IPC-A-620

IPC/WHMA-A-620 January 2002

1 2 3 4 567

Requirements and Acceptance for Cable and Wire Harness Assemblies

®

Developed by the IPC Task Group (7-31f) of the Product Assurance Subcommittee (7-30) and the WHMA Industry Technical Guidelines Committee (ITGC)

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Notice

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©Copyright 2002. IPC, Northbrook, Illinois and Wire Harness Manufacturers Association, Arlington Heights, Illinois. All rights reserved under both international and Pan-American copyright conventions. Any copying, scanning or other reproduction of these materials without the prior written consent of the copyright holder is strictly prohibited and constitutes infringement under the Copyright Law of the United States.

IPC/WHMA-A-620 ASSOCIATION CONNECTING ELECTRONICS INDUSTRIES ®

®

Requirements and Acceptance for Cable and Wire Harness Assemblies

Developed by the IPC Task Group (7-31f) of the Product Assurance Subcommittee (7-30) and the WHMA Industry Technical Guidelines Committee (ITGC)

March 20, 2002

Users of this standard are encouraged to participate in the development of future revisions. Contact: IPC 2215 Sanders Road Northbrook, Illinois 60062-6135 Tel 847 509.9700 Fax 847 509.9798

Wiring Harness Manufacturers Assoc. 3335 N. Arlington Heights Road, Suite E Arlington Heights, Illinois 60004 Tel 847 577.7200 Fax 847 577.7276

This Page Intentionally Left Blank

Acknowledgment Any Standard involving a complex technology draws materials from a vast number of sources. While the principal members of the IPC/WHMA-A-620 joint working group comprised of IPC Task Group (7-31f) of the Product Assurance Subcommittee (7-30) and the WHMA Industry Technical Guidelines Committee (ITGC) are shown below, it is not possible to include all of those who assisted in the evolution of this standard. To each of them, the members of the IPC and WHMA extend their gratitude. Product Assurance Committee

IPC/WHMA-A-620 Joint Working Group

Chair Mel Parrish Soldering Technology International

Garry McGuire, SRSIS NASA/Goddard Space Flight Center

Vernon Judy, Sr. Qualastat Electronics

Technical Liaisons of the IPC Board of Directors

James Moffitt Moffitt Consulting Services

Ray Sweeney Unlimited Services

Dr. William Beckenbaugh Sanmina

Ralph Hersey Ralph Hersey Associates

John A Mastroianni Intercon, Inc.

Members of the IPC/WHMA-A-620 Joint Working Group Troy Agner, ESI America Inc.

Leo P. Lambert, EPTAC Corporation

Tim Armstrong, Global Wire Technologies

Charles A. Lawson,

Roman Belej, Data Cable Company, Inc.

Frederic W. Lee, Northrop Grumman Norden Systems

G. Les Bogert, Bechtel Plant Machinery, Inc.

John A. Mastroianni, Intercon, Inc.

Kim Boyce, Reflect Scientific

Mike Mathews, Electrotest

Mark Brockey, Global Wire Technologies

Karla Maxwell, RF Industries

Byron Case, L-3 Communications

William Dean May, NSWC - Crane

Alan S. Cash, Northrop Grumman Corporation

Wade McFaddin, Nextek, Inc.

Gary W. Chance, Gnubi Communications Inc. Dr. James C. Chiang, Nextek, Inc.

Garry D. McGuire, SRSIS, NASA/Goddard Space Flight Center

Judy Childers, Electronic Theatre Controls

Randy McNutt, Northrop Grumman

Mark Cross, Lockheed Martin

Brett A. Miller, USA Harness, Inc.

Ramon A. Diaz, Solectron Technology Inc.

James H. Moffitt, Moffitt Consulting Services

Bruce Dudley, SAI Spectrum Assembly, Inc.

Anthony M. Monteiro, United Technologies

Eddie Fields, J.C.R. Industries Inc.

Ken A. Moore, Omni Training Corp.

Lila Floria, Electronic Manufacturing, Inc.

Stu Moorhead, Unison Industries

Richard Francis, Carlyle Inc.

Gordon Morris, Raytheon System Technology

Mahendra S. Gandhi, Space Systems/Loral

Kirk Mueller, Boeing Phantom Works

Constantino J. Gonzalez, ACME, Inc.

Kirk D. Mueller, Raytheon Systems Company

Michael R. Green, Lockheed Martin Space Systems

Mary Muller, Eldec Corporation

Hue T. Green, Lockheed Martin Space Systems

Terry L. Munson, CSL Inc.

Ralph J. Hersey, Ralph Hersey Associates

Charles C. Myers, Storage Technology Corp.

Charles Highlan, SCI Systems Inc.

Conrad Neri, RF Industries

David Hollesen, Lucent Technologies, Inc.

Riley L. Northam, EMPF/ACI

Ronald Hotchkiss, Innovative Technology

John S. Norton, Xerox Corporation

Greg Hurst, BAESystems

Seppo Nuppola, Nokia Networks Oyj

James Jenkins, Harris Corporation

Lowell Nutter, Array Connector Corporation

Vernon Judy, Sr., Qualastat Electronics

Gregg Owens, Omni Training Corp.

Brenda Klingenberg, L & L Assemblies Toru Koizumi, Fujikura Ltd.

Deepak K. Pai, C.I.D., General Dynamics Information Sys. Inc.

Richard J. LaFay, RF Industries

Meena Parkera, Western Electronics

IPC/WHMA-A-620

January 2002

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Acknowledgment (cont.) Mel Parrish, Soldering Technology International

Denise Soter, Waters Corporation

Andy Puglisi, Eric Electronics

Rich Stickler, MWC

William A. Rasmus, Jr., Aerojet

Bill Strachan, AsTA - Highbury College

Sam Resurreccion, APW eMech Systems

Ray Sweeney, Unlimited Services

Ronnie Rice, RF Industries

Blen F. Talbot, L-3 Communications

William J. Rickett, Woven Electronics

Ronald E. Thompson, NSWC - Crane

Jon M. Roberts, PEI Electronics, Inc.

Linda Tucker, Blackfox Training Institute

Susan Roder, Rochester Industrial Control Inc.

Sharon T. Ventress, U.S. Army Aviation & Missile Command

Teresa M. Rowe, AAI Corporation

Steve Whittall, Elite Technical, Inc.

Chris La Rue, Crimping & Stamping Technologies, Inc.

Leo Wiemelt, S&C Electric Company

Jan Saris, OCE Technologies B.V.

William J. Wind, ESI Holdings, Inc.

Marlin C. Shelley, Cirris Systems Corporation

James Walter Woodford, Department of Defense

Joseph L. Sherfick, NSWC - Crane

Fonda B. Wu, Raytheon Systems Company

Rick B. Smith, Motorola, Inc. SPECIAL ACkNOWLEDGMENT

We would like to provide special acknowledgment to the following members for providing pictures and illustrations that are used in this revision. Troy Agner, ESI America Inc.

James H. Moffitt, Moffitt Consulting Services

Richard Francis, Carlyle Inc.

Riley L. Northam, EMPF/ACI

Ralph J. Hersey

Seppo Nuppola, Nokia Networks Oyj

Vernon Judy, Sr., Qualastat Electronics

Gregg Owens and Ken A. Moore, Omni Training Corp.1

John A. Mastroianni, Intercon, Inc.

Mel Parrish, Soldering Technology International

Karla Maxwell, RF Industries

Susan Roder, Rochester Industrial Control Inc.

Garry D. McGuire, SRSIS, NASA/Goddard Space Flight Center

Ray Sweeney, Unlimited Services Blen F. Talbot, L-3 Communications

Randy McNutt, Northrop Grumman

1. Figures 3-9, 4-1, 4-3, 4-4, 4-13, 4-14, 4-15, 4-30, 4-33, 4-36, 4-37, 4-39, 4-40, 4-44, 4-45, 4-46, 4-47, 4-51, 4-52, 4-53, 4-54, 4-55, 4-56, 4-57, 4-58, 4-59 are ©Omni Training Corporation, used by permission.

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IPC/WHMA-A-620

Table of Contents 1 Requirements and Acceptance for Cable and Wire Harness Assemblies ................................... 1-1

2 Applicable Documents ................................................ 2-1 2.1 IPC ............................................................................... 2-1

1.1

Scope ........................................................................ 1-1

1.2

Purpose .................................................................... 1-1

1.3

Approach To This Document ................................ 1-1

1.4

Specialized Designs ............................................... 1-1

2.4 American National Standards Institute (ANSI) ........................................................................... 2-2

1.5

Terms and Definitions ........................................... 1-1

2.5 ESD Assocations (ESDA) ......................................... 2-2

1.6

Classes of Products ............................................... 1-1

3 Preparation .................................................................... 3-1

1.7

Document Hierarchy .............................................. 1-2

3.1 Strand Damage ......................................................... 3-2

1.8

Tool and Equipment Control ................................ 1-2

3.2 Conductor - Deformation ........................................ 3-3

1.9

Observable Criteria ................................................ 1-2

3.3 Wire Separation (Birdcaging) .................................. 3-3

1.10 Defects and Process Indicators .......................... 1-3

3.4 Damaged Insulation ................................................. 3-5

1.11 Inspection Conditions ............................................ 1-3

4 Soldered Terminations ................................................ 4-1

2.2 Joint Industry Standards (ANSI J-STD) ................ 2-1 2.3 Department of Defense (Military) .......................... 2-2

1.11.1 1.11.2 1.11.3 1.11.4 1.11.5 1.11.6

Target ................................................................. Acceptable ......................................................... Process Indicator ............................................... Defect ................................................................. Disposition .......................................................... Product Classification Implied Relationships ...................................................... 1.11.7 Conditions Not Specified ....................................

1-3 1-3 1-3 1-3 1-3

4.1 Wire Preparation, Tinning ....................................... 4-2 4.2 Parts Preparation, Gold Removal .......................... 4-3 4.3 Cleanliness ................................................................ 4-4

1-4 1-4

1.12 Electrical Clearance .............................................. 1-4

4.3.1 4.3.2 4.3.3 4.3.4

Prior to Soldering .................................................. Solder Connections .............................................. Particulate Matter .................................................. Flux Residue .........................................................

4-4 4-4 4-4 4-5

1.13 Measurement Units and Applications ................ 1-4

4.4 Insulation .................................................................... 4-6

1.14 Verification of Dimensions ................................... 1-5

4.4.1 Clearance ............................................................. 4-6 4.4.2 Damage from Soldering ........................................ 4-7

1.15 Visual Inspection .................................................... 1-5

4.5 Flexible Sleeve Insulation ....................................... 4-9

1.15.1 Lighting .............................................................. 1-5 1.15.2 Magnification ...................................................... 1-5

4.6 Birdcaged Wire (Soldered) .................................... 4-11

1.16 Electrostatic Discharge (ESD) Protection .......... 1-5 1.17 Workmanship/Handling ......................................... 1-5 1.18 Cleaning ................................................................... 1-5

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Table of Contents (cont.) 4.7 Connection Requirements .................................... 4-12

6.2 Discrete Wire Termination ...................................... 6-9

4.7.1 4.7.2 4.7.3 4.7.3.1 4.7.3.2 4.7.3.3 4.7.4 4.7.5 4.7.6 4.7.7 4.7.8

6.2.1 6.2.2 6.2.3 6.2.4 6.2.5 6.2.6 6.2.7 6.2.8

Terminals ......................................................... Turret Terminals .............................................. Bifurcated Terminals ........................................ Side Route Attachments ................................. Bottom and Top Route Attachments .............. Staked Wires ................................................... Slotted Terminals ............................................ Pierced/Perforated/Punched Terminals ........... Hook Terminals ............................................... Cup Terminals ................................................. Series Connected Terminals ...........................

4-12 4-12 4-14 4-14 4-16 4-17 4-18 4-19 4-20 4-21 4-22

General ................................................................. 6-9 Position of Wire .................................................. 6-10 Overhang (Extension) .......................................... 6-11 Wire Holder ......................................................... 6-13 Damage in Connection Area ............................... 6-15 End Connectors .................................................. 6-16 Wiremount Connectors ....................................... 6-18 Subminiature D-Connector (Series Bus Connector) ................................................... 6-19 6.2.9 Modular Connectors (RJ Type) ........................... 6-21 7 Ultrasonic Welding ....................................................... 7-1

4.8 Solder Requirements ............................................. 4-23

4.8.1 4.8.2 4.8.3 4.8.4 4.8.5 4.8.6 4.8.7 4.8.8

General ............................................................... Fillet .................................................................... Turret Terminals .................................................. Bifurcated Terminals ........................................... Slotted Terminals ................................................ Pierced/Perforated Terminals .............................. Hook Terminals ................................................... Cup Terminals ....................................................

4-24 4-25 4-27 4-28 4-29 4-30 4-31 4-32

5 Crimp Terminations ..................................................... 5-1 5.1 Stamped and Formed Contacts ............................. 5-2

5.1.1 5.1.2 5.1.3 5.1.4 5.1.5 5.1.6

Insulation Support Crimp ...................................... 5-3 Insulation Inspection Window ............................... 5-6 Conductor Crimp .................................................. 5-7 Crimp Bellmouth ................................................. 5-10 Conductor Brush ................................................ 5-11 Carrier Cutoff Tab ............................................... 5-14

5.2 Machined Crimp Contacts .................................... 5-15

5.2.1 Insulation Clearance ............................................ 5.2.2 Insulation Support (Insulation Support Style Contacts) ................................................... 5.2.3 Conductor Location ............................................ 5.2.4 Crimping ............................................................. 5.2.5 Under Size Conductor - CMA Buildup Crimps ...................................................

5-15 5-17 5-18 5-20

7.1 Insulation Clearance ................................................ 7-2 7.2 Weld Nugget .............................................................. 7-3

7.2.1 Geometry .............................................................. 7-3 8 Splices ............................................................................ 8-1 8.1 Soldered Splices ....................................................... 8-2

8.1.1 8.1.2 8.1.3 8.1.4

Mesh .................................................................... Wrap ..................................................................... Hook ..................................................................... Lap .......................................................................

8-2 8-3 8-4 8-5

8.2 Splices - Crimped ..................................................... 8-6

8.2.1 Barrel .................................................................... 8-6 8.2.2 Double Sided ........................................................ 8-8 8.3 Splices - Ultrasonic Welded ................................. 8-11 9 Connectorization .......................................................... 9-1 9.1 Hardware Mounting .................................................. 9-2

9.1.1 Jackscrews ........................................................... 9-2 9.2 Strain Relief ............................................................... 9-3

9.2.1 Sleeving ................................................................ 9-3 5-22 9.3 Sleeving and Boots ................................................... 9-4

6 Insulation Displacement Connection (IDC) ............. 6-1

9.3.1 Position ................................................................. 9-4 9.3.2 Bonding - Conductive Adhesive ........................... 9-5

6.1 Mass Termination, Flat Cable ................................ 6-2

6.1.1 6.1.2 6.1.3 6.1.4 6.1.5 6.1.6

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End Cutting .......................................................... Notching ............................................................... Planar Ground Plane Removal .............................. Connector Position ............................................... Connector Skew and Lateral Position ................... Retention ..............................................................

6-2 6-3 6-4 6-5 6-7 6-8

9.4 Connector Damage ................................................... 9-7

9.4.1 Criteria .................................................................. 9-7 9.4.2 Limits - Hard Face - Mating Surface ..................... 9-8 9.4.3 Limits - Soft Face - Mating Surface or Rear Seal Area ..................................................... 9-9 9.4.4 Contacts ............................................................. 9-10

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Table of Contents (cont.) 10 Molding/Potting ........................................................ 10-1

13.2

10.1 Molding ................................................................... 10-2

13.2.1 Crimp ............................................................... 13-4 13.2.2 Solder ............................................................... 13-6

10.1.1 10.1.2 10.1.3 10.1.4 10.1.5 10.1.6

Insulation Damage ............................................ Filling ................................................................ Terminal Positioning ......................................... Fit to Wire or Cable .......................................... Flashing ............................................................ Chill Marks (Knit Lines), Stress Lines or Cracks ......................................................... 10.1.7 Compound Color ..............................................

10-2 10-3 10-5 10-6 10-8

13.3

13.4

Coaxial Connector - Printed Wire Board Mount ...................................................... 13-11

13.5

Coaxial Connector - Center Conductor Length - Right Angle Connector .................... 13-12

13.6

Terminal Cover - Soldering ............................ 13-14

13.7

Shield Termination ........................................... 13-16

10.2 Potting .................................................................. 10-10

11 Cable Assemblies and Wires ................................. 11-1

Solder Ferrule Pins ............................................ 13-8

13.3.1 General ............................................................. 13-8 13.3.2 Insulation ........................................................ 13-10

10-9 10-9

10.2.1 Filling .............................................................. 10-10 10.2.2 Fit to Wire or Cable ........................................ 10-11 10.2.3 Curing ............................................................ 10-12

Center Conductor Termination ........................ 13-4

13.7.1 Clamped Ground Rings .................................. 13-16 13.7.2 Crimped Ferrule .............................................. 13-17

11.1 Cable Assemblies ................................................. 11-2

11.1.1 11.1.1.1 11.1.1.2 11.1.2

Reference Surfaces ........................................ Straight/Axial Connectors ............................... Right-Angle Connectors ................................. Length Measurement .....................................

11-2 11-2 11-2 11-3

13.8

Center Pin Position .......................................... 13-19

13.9

Semirigid Coax .................................................. 13-20

11.2.1 Electrical Terminal Reference Location ............. 11-4 11.2.2 Length Measurement ....................................... 11-5

13.9.1 13.9.2 13.9.3 13.9.4 13.9.5

12 Marking/Labeling ..................................................... 12-1

13.10 Swage-Type Connector ................................... 13-30

12.1 Content ................................................................... 12-2 12.2 Legibility ................................................................. 12-2

13.11 Soldering and Stripping of Biaxial or Twinaxial Wire - Low Temperature Insulation ........................................................... 13-31

12.3 Permanency ........................................................... 12-4

13.11.1 Jacket and Tip Installation ............................. 13-31 13.11.2 Ring Installation ............................................. 13-33

12.4 Location .................................................................. 12-4

14 Wire Bundle Securing ............................................. 14-1

12.5 Functionality .......................................................... 12-5

14.1

11.2 Wires (As an Assembly) ....................................... 11-4

12.6 Marker Sleeve ....................................................... 12-6

12.6.1 Wrap Around .................................................... 12-6 12.6.2 Tubular ............................................................. 12-8

13.1 Stripping ................................................................. 13-2

IPC/WHMA-A-620

13-20 13-23 13-24 13-27 13-28

Tie Wrap/Lacing Application ............................ 14-2

14.1.1 Tightness .......................................................... 14-6 14.1.2 Damage ............................................................ 14-7 14.1.3 Spacing ............................................................ 14-8 14.2

13 Coaxial and Twinaxial Cable Assemblies ............ 13-1

Bending and Deformation ............................... Surface Condition ........................................... Dielectric Cutoff .............................................. Dielectric Cleanliness ...................................... Solder .............................................................

Breakouts ............................................................. 14-9

14.2.1 Individual Wires ................................................ 14-9 14.2.2 Spacing .......................................................... 14-10

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Table of Contents (cont.) 14.3 Wire Bundles ....................................................... 14-13

14.3.1 14.3.2 14.3.3 14.3.4

Wire Crossover ............................................... Coaxial Cable Routing .................................... Unused Wire Termination ............................... Ties over Splices and Ferrules ........................

14-13 14-14 14-15 14-16

17 Installation ................................................................ 17-1 17.1 General ................................................................... 17-2 17.2 Hardware Installation .......................................... 17-3

15.1.1 Direct Applied ................................................... 15-3 15.1.2 Pre-Woven ....................................................... 15-4

17.2.1 Sequence ......................................................... 17-4 17.2.2 Type and Missing ............................................. 17-6 17.2.3 Minimum Torque for Electrical Connections ..................................................... 17-7 17.2.4 Wires ................................................................ 17-8 17.2.5 High Voltage Applications ............................... 17-11

15.2 Shield Termination ............................................... 15-5

17.3 Wire/Harness Installation ................................. 17-12

15.2.1 Pick Off ............................................................ 15-5 15.2.2 No Pick Off ..................................................... 15-11 15.2.3 Low Temperature Insulated Wire With Pick Off .................................................. 15-13

17.3.1 Stress Relief ................................................... 17-12 17.3.2 Wire Dress ...................................................... 17-13 17.3.3 Service Loops ................................................ 17-14

15 Shielding .................................................................... 15-1 15.1 Braided ................................................................... 15-2

18 Solderless Wrap ....................................................... 18-1 15.3 Shield Termination - Shrink and Crimp ......... 15-15 18.1 Number of Turns ................................................... 18-2 15.4 Shield Termination - Splicing ........................... 15-19 18.2 Turn Spacing ......................................................... 18-3 15.5 Tapes - Barrier and Conductive, Adhesive or Non-Adhesive ................................ 15-21

18.3 End Tails, Insulation Wrap .................................. 18-4

15.6 Conduit (Shielding) ............................................. 12-22

18.4 Raised Turns Overlap .......................................... 18-6

15.7 Conductive Coating ............................................ 15-23

18.5 Connection Position ............................................. 18-7

15.8 Shrink Tubing - Conductive Lined .................. 15-24

18.6 Wire Dress ............................................................. 18-9

16 Cable/Wire Harness Protective Coverings ......... 16-1

18.7 Wire Slack ............................................................ 18-10

16.1 Braid ........................................................................ 16-2

18.8 Plating ................................................................... 18-11

16.1.1 Direct Applied ................................................... 16-2 16.1.2 Pre-Woven ....................................................... 16-4

18.9 Damage ................................................................ 18-12

16.2 Taping ..................................................................... 16-5

18.9.1 Insulation ........................................................ 18-12 18.9.2 Wires and Terminals ....................................... 18-13

16.3 Sleeving .................................................................. 16-6

Appendix A ......................................................................... A-1

16.3.1 Shrink Tubing ................................................... 16-6 16.4 Spiral Plastic Wrap (Spiral Wrap Sleeving) ......................................... 16-7

Appendix B ........................................................................ B-1 Standard Improvement Form

16.5 Conduit (Containment) ........................................ 16-8

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1 Requirements and Acceptance for Cable and Wire Harness Assemblies

Foreword 1.1 Scope

This standard is a collection of visual Quality Acceptability Requirements for Cable, Wire and Harness Assemblies. It was prepared by the ITGC Industry Technical Guidelines Committee of the Wire Harness Manufacturers Association and the Product Assurance Committee of IPC - Association Connecting Electronic Industries. IPC/WHMA-A-620 can be used as a stand-alone document for purchasing products, however it does not specify frequency of in-process inspection or frequency of end product inspection. No limit is placed on the number of process indicators or the number of allowable repair/rework of defects. Such information should be developed with a statistical process control plan (see IPC-9191).

1.5 Terms and Definitions

Terms are consistent with the definitions provided by IPC-T50. For the understanding of this document, selected definitions are listed below and in Appendix A. Shall or Must – Mean that the requirement or attribute discussed is mandatory for all Product Classes. Should – Reflects recommendations and is used to reflect general industry practices and procedures for guidance only.

1.2 Purpose

This publication describes acceptability criteria for producing crimped, mechanically secured, or soldered interconnections and the associated lacing/restraining criteria associated with cable and harness assemblies. It is not the intent of this document to exclude any acceptable procedure used to make the electrical connection; however, the methods used must produce completed assemblies that conform to the acceptability requirements described in this document. 1.3 Approach To This Document

The illustrations in this document portray specific points noted in the title of each section. A brief description follows each illustration. The development committee recognizes that different parts of the industry have different definitions for some terms used herein. For the purposes of this document, the terms cable and wire harness are used interchangeably. 1.4 Specialized Designs

IPC/WHMA-A-620, as an industry consensus document, cannot address all of the possible product design combinations. However, the standard does provide criteria for commonly used technologies. Where uncommon or specialized technologies are used, it may be necessary to develop unique acceptance criteria. The development of unique criteria should include customer involvement or consent and the criteria developed should include an agreed upon definition for acceptance of each characteristic.

IPC/WHMA-A-620

Whenever possible, new criteria, or criteria on specialized products should be submitted, using the Standard Improvement Form included in this standard, to the IPC Technical Committee to be considered for inclusion in upcoming revisions of this standard.

Wire Diameter – In this document, wire diameter (D) is the overall diameter of conductor plus insulation. 1.6 Classes of Products

The customer has the ultimate responsibility for identifying the class to which the assembly is evaluated. Thus, accept and/or reject decisions must be based on applicable documentation such as contracts, drawings, specifications, standards and reference documents. Criteria defined in this standard reflect three Product Classes, which are as follows: Class 1 – General Electronic Products

Includes products suitable for applications where the major requirement is the function of the completed assembly. Class 2 – Dedicated Service Electronic Products

Includes products where continued performance and extended life is required, and for which uninterrupted service is desired but not critical. Typically, the end-use environment would not cause failures. Class 3 – High Performance Electronic Products

Includes products where continued performance or performance-on-demand is critical, equipment downtime cannot be tolerated, end-use environment may be uncommonly harsh, and the equipment must function when required, such as life support systems and other critical systems.

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Foreword 1.7 Document Hierarchy

In the event of conflict, the following order of precedence applies: 1. Procurement as agreed between customer and vendor. 2. Master drawing or master assembly drawing reflecting the customer’s detailed requirements. 3. When invoked by the customer or per contractual agreement, IPC/WHMA-A-620. 4. Other documents to extent specified by the customer. The developing committee recognizes that some requirements in IPC/WHMA-A-620 differ from those in other industry standards such as IPC-A-610 and IPC/EIA J-STD-001. When IPC/WHMA-A-620 is cited or required by contract as a standalone document for inspection and/or acceptance, the requirements of IPC/EIA J-STD-001 Requirements for Soldered Electrical and Electronic Assemblies or IPC-A-610 Acceptability of Electronic Assemblies do not apply unless separately and specifically required. When IPC/WHMA-A-620, IPC/EIA J-STD-001, IPC-A-610 and/or other related documents are cited, the order of precedence is to be defined in the procurement documents.

a. Measurement standards used for calibrating tools shall be traceable to National Institute of Standards and Technology (NIST). Calibration of tools shall be performed in an environment compatible with the environmental requirements of the tools. b. Calibration intervals shall be based on the type of tool and records of the tool’s calibration. Intervals may be lengthened or shall be shortened on the basis of stability demonstrated over previous calibration periods. c. Procedures shall be generated and utilized for the calibration of all tooling stated herein. Procedures shall include, as a minimum, standards to be used, parameters to be measured, accuracy, tolerances, environmental factors, and steps in the calibration process. The procedures may be the manufacturer’s specifications if judged adequate, and need not therefore be rewritten, but shall be documented. d. Records shall be maintained that document calibration. e. Tools shall be labeled to indicate, as a minimum: (1) Date of calibration. (2) Calibration due date.

The user (customer) has the opportunity to specify alternate acceptance criteria.

(3) Any limitation of use. If not practical to place the label directly on the tool, then the label shall be affixed to the tool container or other location as documented in the procedures.

1.8 Tool and Equipment Control

(4) Tool identification.

Each manufacturer shall: a. Select tools to be used for crimping, cabling, wiring, measuring, inspecting and in work preparation areas appropriate to the intended function. b. Clean and properly maintain all tools and equipment. c. Examine all elements of tools, used in cabling, for physical damage. d. Prohibit unauthorized, defective, or uncalibrated tools in the work area. e. Document detailed operating procedures and maintenance schedules for tools and equipment requiring calibration or set-ups. f. Maintain records of tool and equipment calibration and functional testing.

1.9 Observable Criteria

The manufacturer shall have a documented calibration system in accordance with ANSI/NCSL Z540-1 or other National or International standard. The minimum standard shall be:

In the case of a discrepancy, the written description or written criteria always takes precedence over the illustrations.

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The acceptance criteria of this standard are based on visual inspection of the assemblies. Visual inspection may be supplemented by the measurement of characteristics appropriate to the product being assembled (e.g., go/no-go gauges, pull force measurements, torque measurement). Measurement of dimensions provided in this standard (i.e., insulation extension, solder fillet percentage, crimp depth dimensions and determination of percentages) is not required except for referee purposes. Many of the examples (figures) shown are grossly exaggerated to clearly depict the condition being described.

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Foreword 1.10 Defects and Process Indicators

Characteristics or conditions that do not conform to the requirements of this standard that are detectable by inspection or analysis are classified as either defects or process indicators. Not all process indicators are specified by this standard. Process indicators should be monitored but the hardware need not be dispositioned (see 1.11.3). It is the responsibility of the user to define unique defect categories applicable to the product. It is the responsibility of the manufacturer to identify defects and process indicators that are unique to the assembly.

• Such condition is a result of material, design and/or operator/machine related causes that create a condition that neither fully meets the acceptance criteria nor is a defect. • Process indicators should be monitored as part of the process control system. If the number of process indicators indicates an abnormal variation in the process, identifies an undesirable trend, or displays other conditions that indicate the process is (or is approaching) out of control, the process shall be analyzed. This may result in action to reduce the variation and improve yields. • Disposition of individual process indicators is not required and affected product should be used as is.

1.11 Inspection Conditions

For this document, target, acceptable and defect conditions are listed for each product class. Where applicable, process indicator conditions are also listed. The inspector shall not select the product class for the assembly under inspection. Documentation that specifies the applicable class for the assembly under inspection shall be provided to the inspector. The descriptions of these conditions follow. 1.11.1 Target

A condition that is close to perfect (in the past has sometimes been labeled as ‘‘preferred’’). It is a desirable condition, not always achievable, and may not be necessary to ensure reliability of the assembly in its service environment. 1.11.2 Acceptable

This characteristic indicates a condition that, while not necessarily perfect, will maintain the integrity and reliability of the assembly in its service environment.

• Process control methodologies are to be used in the planning, implementation and evaluation of the manufacturing processes used to produce soldered electrical and electronic assemblies. The philosophy, implementation strategies, tools and techniques may be applied in different sequences depending on the specific company, operation, or variable under consideration to relate process control and capability to end product requirements. The manufacturer needs to maintain objective evidence of a current process control/continuous improvement plan that is available for review. 1.11.4 Defect

A defect is a condition that fails to meet the acceptance criteria of this document and is insufficient to ensure the form, fit, function, or reliability of the assembly in its end use environment. The manufacturer must document and disposition each defect. 1.11.5 Disposition

1.11.3 Process Indicator

A process indicator is a condition (not a defect) that identifies a characteristic that does not affect the ’’form, fit, function or reliability’’ of a product.

IPC/WHMA-A-620

Disposition is the determination of how defects should be treated. Dispositions include, but are not limited to, rework, use as is, scrap or repair. Customer concurrence may be required for use as is dispositions.

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Foreword Table 1-1

1.11.6 Product Classification Implied Relationships

A defect for a Class 1 product means that the characteristic is also a defect for Class 2 and 3. A defect for a Class 2 product means that the characteristic is also a defect for a Class 3 product, but may not be a defect for a Class 1 product where less demanding criteria may apply. 1.11.7 Conditions Not Specified

Conditions that are not specified as defective or as a process indicator are considered acceptable unless it can be established that the condition affects end user defined form, fit, function or reliability. 1.12 Electrical Clearance

Electrical clearance spacing between conductors should be maximized whenever possible. The minimum spacing between conductors, and between conductive materials (such as conductive markings or mounting hardware) and conductors should be defined on the applicable drawings or documentation. When mixed voltages appear on the same assembly, the specific areas and appropriate clearances should be identified on the master drawing. Failure to adhere to this criteria can cause equipment operating problems, and in the case of high voltages or high power applications, potential severe damage/fire. Although minimum electrical clearance distances are normally fixed by the design/drawing (e.g., minimum spacing between two terminal studs), it is possible to violate the minimum spacing by the installation method. For example, improper orientation of an uninsulated terminal lug or an excessively long wire wrap/solder connection pigtail with orientation that places the connections closer to non-electrically common conductors could violate the minimum spacing. Electrical clearance distance is defined as the shortest pointto-point distance in air between uninsulated energized parts or between an energized part and ground. The minimum electrical clearance distance depends on the circuit voltage rating and the normal volt-ampere rating. In cases where no minimum electrical clearance value is otherwise defined, the criteria in Table 1-1 (excerpted from MIL-E-917) may be used as a guideline.

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Electrical Clearance

Voltage

Set*

Clearance

Up to 64

A B C

1.6 mm [0.062 in] 3.2 mm [0.125 in] 3.2 mm [0.125 in]

Over 64-150

A B C

1.6 mm [0.062 in] 3.2 mm [0.125 in] 6.4 mm [0.25 in]

Over 150-300

A B C

1.6 mm [0.062 in] 3.2 mm [0.125 in] 6.4 mm [0.25 in]

Over 300-600

A B C

1.6 mm [0.062 in] 3.2 mm [0.125 in] 6.4 mm [0.25 in]

Over 600-1000

A B C

3.2 mm [0.125 in] 6.4 mm [0.25 in] 12.7 mm [0.5 in]

Over 1000-3000

A B C

50 mm [2 in]

Over 3000-5000

A B C

75 mm [3 in]

*Set A = Normal operating volt-ampere rating up to 50. *Set B = Normal operating volt-ampere rating of 50 to 2000. *Set C = Normal operating volt-ampere rating over 2000.

1.13 Measurement Units and Applications

All dimensions and tolerances as well as other forms of measurement (temperature, weight, force, etc.) in this standard are expressed in SI (System International) units (with Imperial English equivalent dimensions provided in brackets). Dimensions and tolerances use millimeters as the main form of dimensional expression; micrometers are used when the precision required makes millimeters too cumbersome. Celsius is used to express temperature. Weight is expressed in grams. ‘‘Hard’’ measurements are used for both SI and Imperial English. Rounding may cause variations between the two actual measurements. The order of precedence (SI or Imperial) is to be defined in the procurement documents. Appendix B is a cross-reference of English (Imperial) to SI units.

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Foreword 1.14 Verification of Dimensions

Actual measurement of specific part mounting and solder fillet dimensions and determination of percentages are not required except for referee purposes. For the purposes of determining conformance to this specification, all specified limits in this standard are absolute limits as defined in ASTM E29.

Referee magnification power is to be used only to verify a product rejected at the inspection magnification. For assemblies with mixed wire size, the greater magnification may be (but is not required to be) used for the entire assembly. 1.16 Electrostatic Discharge (ESD) Protection

1.15 Visual Inspection

Assemblies that contain components or parts sensitive to ESD must be protected. ESD protection shall be in accordance with ANSI/ESD-S20.20-1999 or as otherwise specified.

1.15.1 Lighting

1.17 Workmanship/Handling

Illumination at the surface of workstations should be 1000 lm/m2 minimum. 1,000 lm/m2 at the work surface is the accepted practice for the minimum level of illumination in which operators and inspectors should be expected to perform their tasks. 1,000 lm/m2 is approximately equivalent to 100 foot-Lamberts measured using a photographic light meter.

Care must be taken during assembly activities and acceptability inspections to ensure product integrity at all times. Improper handling can readily damage components and assemblies (e.g., cracked, chipped or broken components and connectors, broken wire strands, or bent or broken terminals). Physical damage of this type can ruin the entire assembly or attached components.

1.15.2 Magnification

1.18 Cleaning

Magnification aids in accordance with Table 1-2 below shall be used for visual inspection of in-process and completed assemblies. The tolerance for magnification aids is 15% of the selected magnification power, (i.e., 15% or a range of 30% centered at the selected magnification power). The magnification power of aids used for inspection need to be appropriate with the item being processed. Lighting needs to be adequate for the magnification aids used and thus may exceed 100 foot-Lamberts in some cases. The magnification used is based on the AWG size (gauge) of the wire being inspected. The magnification levels shown in Table 1-2 shall apply:

Assemblies produced in accordance with this Standard shall be free of all extraneous matter (including but not limited to: wire clippings, insulation slugs, strands of shielding braid or any other item not required to be present). See Section 4 for cleanliness criteria specific to soldered assemblies.

Table 1-2

Magnification Aids Inspection

Referee

Wire Size AWG Diameter mm [inch]

Magnification Power

Magnification Power

>14 AWG 2.0 mm [0.081]

N/A

1.75X

14 to 22 AWG 1.6 - 0.63 mm [0.064 to 0.025]

1.75X

4X

<22 AWG >0.63 mm [<0.025]

4X

10X

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2 Applicable Documents

Applicable Documents

2.1 IPC IPC-9191

General Guidelines for Implementation of Statistical Process Control (SPC)

IPC-T-50

Terms and Definitions for Interconnecting and Packaging Electronic Circuits

IPC-CH-65

Guidelines for Cleaning of Printed Boards and Assemblies

IPC-A-610

Acceptability of Electronic Assemblies

IPC-TM-650

Test Methods Manual

2.2 Joint Industry Standards (ANSI J-STD) IPC/EIA J-STD-001 Requirements for Soldered Electrical and Electronic Assemblies

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2 Applicable Documents

2.3 Department of Defense (Military) MIL-E-917

Electric Power Equipment Basic Requirements

2.4 American National Standards Institute (ANSI) ANSI/NCSL

Z540-1-1994

2.5 ESD Association (ESDA) Association Standard for the Development of an Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment

ANSI/ESD-S20.20-1999 ESD

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3 Preparation

Preparation This section provides requirements and acceptance criteria for preparation of wires that will be used in the cable/wire harness fabrication process. The following topics are addressed in this section: 3.1 Strand Damage 3.2 Conductor - Deformation 3.3 Wire Separation (Birdcaging) 3.4 Damaged Insulation

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3 Preparation

3.1 Strand Damage Target Condition - Class 1,2,3

• Strands are not scraped, nicked, severed or otherwise damaged.

Figure 3-1

Acceptable - Class 1 Process Indicator - Class 2,3

• Strands scraped, nicked, or severed but does not exceed the limits specified in Table 3-1. Defect - Class 1,2,3 Figure 3-2

• Scraped, nicked (1), or severed strands exceed the limits specified in Table 3-1. Table 3-1

Maximum Allowable Strands Scraped, Nicked or Severed for Class 1,2

Maximum Allowable Strands Scraped, Nicked or Severed for Class 3 Crimped Terminations

Maximum Allowable Strands Scraped, Nicked or Severed for Class 3 Soldered Terminations

Less than 7

0

0

0

7-15

1

0

1

16-25

3

0

2

26-40

4

3

3

41-60

5

4

4

Number of Strands

Figure 3-3

Allowable Strand Damage

61-120 121 or more

6

5

5

6%

5%

5%

Note 1: The requirements in Table 3-1 are different than the wire/strand damage requirements of IPC-A-610 and IPC/EIA-J-STD-001 (see 1.7). Note 2: No damaged strands for wires used at a potential for 6 kV or greater.

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3 Preparation

3.2 Conductor – Deformation Target – Class 1,2,3

• Strands are not flattened, untwisted, buckled, kinked or otherwise deformed.

Figure 3-4 Acceptable - Class 1,2,3

• Wire strands disturbed during insulation removal have been restored to approximate their original lay.

Figure 3-5

3.3 Wire Separation (Birdcaging) Target - Class 1,2,3

• No birdcaging. Acceptable - Class 1,2,3

• Wire strands have separation (birdcaging) but do not exceed the lesser of: • One strand diameter or • Do not extend beyond wire insulation outside diameter. Figure 3-6

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3 Preparation

3.3 Wire Separation (Birdcaging) (cont.) Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Wire strands have separation exceeding one strand diameter but do not extend beyond wire insulation outside diameter.

Figure 3-7

Acceptable - Class 1 Defect - Class 2,3

• The general spiral lay of the strands has not been maintained. • Wire strands extend beyond wire insulation outside diameter. Figure 3-8

Defect - Class 1,2,3

• Wire strands are kinked.

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3 Preparation

3.4 Damaged Insulation Target - Class 1,2,3

• Insulation has been trimmed neatly with no signs of pinching, pulling, fraying, discoloration, charring or burning.

Figure 3-9

Acceptable - Class 1,2,3

• Slight uniform impression in the insulation from the gripping of mechanical strippers. • Insulation thickness is not reduced by more than 20%. • Uneven or ragged pieces of insulation is less than 50% of the insulation outside diameter or 1.0 mm [0.039 in] whichever is less. • Insulation is discolored from the thermal stripping operation. Figure 3-10

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3 Preparation

3.4 Damaged Insulation (cont.) Defect - Class 1,2,3

• Any cuts or breaks in insulation (not shown). • Insulation thickness is reduced by more than 20% (Figures 3-11, 3-12). • Uneven or ragged pieces of insulation are greater than 50% of the insulation outside diameter or 1.0 mm [0.039 in] whichever is more (Figure 3-13). • Insulation is charred (Figure 3-14). • Insulation is melted into the wire strands (not shown). Figure 3-11

Figure 3-12

Figure 3-13

Figure 3-14

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4 Soldered Terminations

Soldered Terminations Soldered terminations are used infrequently in cable/harness assembly and for that reason may merit special consideration. IPC-HDBK-001 provides additional technical information and guidance on how to achieve solder connections that comply with the requirements stated below.

4.5 Flexible Sleeve Insulation

This section separately provides lead forming/placement and soldering criteria. Forming and placement for all terminal types is provided first, followed by soldering criteria beginning at 4.8.

4.7.1 4.7.2 4.7.3 4.7.3.1 4.7.3.2 4.7.3.3 4.7.4 4.7.5 4.7.6 4.7.7 4.7.8

Stranded wires shall be tinned prior to forming for attachment to solder terminals. (Stranded wires for attachment to crimp terminals shall not be tinned, see 5 Crimped Terminations.) The following topics are addressed in this section. 4.1 Wire Preparation, Tinning

4.6 Birdcaged Wire (Soldered) 4.7 Connection Requirements

Terminals Turret Terminals Bifurcated Terminals Side Route Attachments Bottom and Top Route Attachments Staked Wires Slotted Terminals Pierced/Perforated/Punched Terminals Hook Terminals Cup Terminals Series Connected Terminals

4.2 Parts Preparation, Gold Removal 4.8 Solder Requirements 4.3 Cleanliness

4.3.1 4.3.2 4.3.3 4.3.4

Prior to Soldering Solder Connections Particulate Matter Flux Residue

4.4 Insulation

4.4.1 4.4.2

Clearance Damage from Soldering

IPC/WHMA-A-620

4.8.1 4.8.2 4.8.3 4.8.4 4.8.5 4.8.6 4.8.7 4.8.8

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General Fillet Turret Terminals Bifurcated Terminals Slotted Terminals Pierced/Perforated Terminals Hook Terminals Cup Terminals

4-1


4.1 Wire Preparation, Tinning Purpose – Tinning is primarily performed to assure that the wire to be soldered has a uniform and readily solderable surface. Tinning of stranded wire has the added benefit of bonding the individual wire strands together, thereby allowing the wire to be formed to terminals or attachment points without separation of the individual strands. Note: Wires intended to be secured in threaded fasteners or crimp terminations shall never be tinned. For Classes 2 and 3: • Portions of wire that will be soldered shall be tinned prior to mounting. • The solder shall wet the tinned portion of the wire and penetrate to the inner strands of stranded wire. • Limited solder wicking during soldering of wire is permissible as long as the solder does not extend to a portion of the wire that is required to remain flexible. The tinning should leave a smooth coating of solder, and the outline of the strands should be visible.


• Wire is uniformly coated with a smooth solder coat. • Stranded wire is uniformly coated with a thin coat of solder with the individual strands of the wire easily visible. • Untinned length of strands from end of insulation is not greater than one wire diameter (D). Process Indicator - Class 2,3

Figure 4-1

• Strands not discernible but does not interfere with form, fit, function or reliability. Defect - Class 2,3

• Stranded wire not tinned prior to assembly. Defect - Class 1,2,3

• Wire has pinholes, voids or areas where solder has not wetted to the wire. Defect - Class 3

• Length of untinned strands from end of insulation is greater than one wire diameter (D).

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4.2 Parts Preparation, Gold Removal Gold shall be removed from 95% of all surfaces to be soldered, regardless of gold thickness. A double tinning process or dynamic solder wave may be used for gold removal. These requirements may be eliminated if there is documented objective evidence available for review that there are no gold related solder problems associated with the soldering process being used. Acceptable - Class 1,2,3

• Gold plated parts have been tinned to eliminate gold from areas to be soldered. Process Indicator - Class 2 Defect - Class 3

• Gold plated parts have not been tinned to eliminate gold from areas to be soldered.

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4.3 Cleanliness

4.3.1 Cleanliness – Prior to Soldering Cleanliness of terminals, component leads, and conductors shall be sufficient to assure solderability prior to soldering operations.

4.3.2 Cleanliness – Solder Connections Assemblies using soldered connections shall be visually examined to detect the presence of flux residues and particulate matter. The visual examination may, based on product application and customer/user needs/requirement, need to be supplemented with extraction based tests. For information on cleaning assemblies see IPC-CH-65 (Cleaning Handbook). For information on extraction based tests see IPC/EIA J-STD-001 and/or Test Methods of IPC-TM-650. Solder connections that are accomplished using flux chemistries that are intended to be cleaned, should be cleaned in a manner that assures removal of residual flux and activators. Methods and materials that are used to clean soldered assemblies shall be compatible with the product and assembly materials so that the cleaning process does not adversely affect the performance characteristics.

4.3.3 Cleanliness – Particulate Matter No illustrations. Target - Class 1,2,3

• Clean. Defect - Class 1,2,3

• Dirt and particulate matter on assembly, e.g., solder splatter, solder balls, dirt, lint, dross, metallic particles, etc.

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4.3.4 Cleanliness – Flux Residue Flux residue may be present if it is no-clean flux residue that is not intended to be cleaned. (No illustrations) Target - Class 1,2,3

• No visible flux residue. Acceptable - Class 1 Process Indicator - Class 2,3

• Flux residue does not inhibit visual inspection. • Flux residue does not inhibit access to test points of the assembly. Acceptable - Class 1 Defect - Class 2,3

• Flux residue on, around, or bridging between noncommon conductors. • Flux residue inhibits visual inspection. • Flux residue inhibits access to test points of the assembly. Defect - Class 1,2,3

• Wet, tacky, or excessive flux residues that may spread onto other surfaces. • No-clean flux residue on any electrical mating surface that inhibits electrical connection.

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4.4 Insulation

4.4.1 Insulation – Clearance Target - Class 1,2,3

• There is an insulation clearance (C) of one diameter (D) between the end of the insulation and the top of the solder fillet.


• The insulation clearance is two wire diameters (D) or less including insulation or 1.5 mm [0.060 in] (whichever is greater). • Insulation clearance does not permit shorting to adjacent conductors. • Insulation clearance is near zero.

Figure 4-3

Figure 4-4

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4.4.1 Insulation – Clearance (cont.) Process Indicator - Class 2,3

• The insulation clearance is greater than two wire diameters including insulation or 1.5 mm [0.060 in], whichever is greater, but does not permit shorting to adjacent conductor. Defect - Class 1,2,3

• Insulation clearance permits shorting to adjacent conductors.

Figure 4-5

4.4.2 Insulation – Damage from Soldering Target - Class 1,2,3

• Insulation is not melted, charred or otherwise damaged from the soldering process.

Figure 4-6

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4.4.2 Insulation – Damage from Soldering (cont.) Acceptable - Class 1,2,3

• Slight melting of insulation.

Figure 4-7

Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Wire insulation is embedded in the solder.

Figure 4-8


• Insulation charred. • Solder connection contaminated by burnt or melted insulation.

Figure 4-9

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4.5 Flexible Sleeve Insulation Target - Class 1,2,3

• Insulation sleeving overlaps the connector terminal (at arrows) and extends over the wire insulation four wire diameters (D). • Insulation sleeving is one wire diameter (D) from the point where the connector terminal enters the connector insert.

Figure 4-10


• Insulation sleeving overlaps the connector terminal and the wire insulation by a minimum of two wire diameters, whichever is smaller. • Insulation sleeving is more than 50% wire diameter and not more than two wire diameters from the point where the connector terminal enters the connector insert.

Figure 4-11

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4.5 Flexible Sleeve Insulation (cont.) Defect - Class 2,3

• Insulation sleeving is split (A). • Insulation sleeving overlaps the wire insulation by less than two wire diameters (B). • Insulation sleeving is more than two wire diameters from the point where the connector terminal enters the connector insert (C). • Insulation sleeve is loose on the terminal (could slide or vibrate off, exposing more than the allowed amount of conductor or terminal) (D). • Insulation sleeving is less than 50% wire diameter from the point where the connector terminal enters the connector insert (A, B, D). Figure 4-12

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4.6 Birdcaged Wire (Soldered) Target - Class 1,2,3

• No birdcaging. Acceptable - Class 1,2,3

• Wire strands have separation (birdcaging) (see Figure 3-6) but do not exceed the lesser of: • One strand diameter or • Do not extend beyond wire insulation outside diameter.

Figure 4-13


• Wire strands have separation exceeding one strand diameter but do not extend beyond wire insulation outside diameter. • The general spiral lay of the strands has not been maintained.

Figure 4-14

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4.7 Connection Requirements

4.7.1 Connection Requirements – Terminals Applies to both wires and component leads. The preferred wrap conditions achieve a mechanical connection between the lead/ wire and the terminal sufficient to assure that the lead/wire does not move during the soldering operation. Typically the mechanical connection includes a 180° mechanical wrap to effect mechanical connection. As an exception to the wrap conditions described above, it is acceptable when attaching leads/wires to bifurcated, slotted, pierced, punched or perforated terminals for the lead/wire to extend straight through the opening of the terminal with no wrap. Except for slotted terminals (4.6.4), leads/wires with no wrap shall be staked, bonded, or constrained to a degree that: • assures the wire/terminal interface will not be disturbed (moved) during the soldering operation • the solder connection is protected from any force subsequently exerted on the lead/wire.

4.7.2 Connection Requirements – Turret Terminals Target - Class 1,2,3

• Wraps parallel to each other and to the base. • Wire mounted against terminal base. • On straight pins, the top wire on terminal is one wire diameter below the top of the terminal. • Wraps are a minimum of 180° and a maximum of 270°.

Figure 4-15

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4.7.2 Connection Requirements – Turret Terminals (cont.) Acceptable - Class 1,2,3

• Wires and leads mechanically secure to terminals before soldering. • Wires and leads wrapped a minimum of 180° and do not overlap.

Figure 4-16 1. Upper guide slot 2. Lower guide slot 3. Base

Process Indicator - Class 2,3

• Wire end overlaps itself. Defect - Class 2

• Wrap has less than 90° contact between the wire and terminal. Process Indicator - Class 2 Defect - Class 3

• Minimum wrap for round posts has less than 180° of contact between the wires and the terminal.

Figure 4-17

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4.7.3 Connection Requirements – Bifurcated Terminals 4.7.3.1 Connection Requirements – Bifurcated Terminals – Side Route Attachments Target - Class 1,2,3

• The wire or lead contacts two parallel faces (180° bend) of the terminal post. • The cut end of the wire contacts the terminal (not shown). • No overlapping of wraps. • Wires placed in ascending order with largest on the bottom. • Multiple wire attachments alternate terminal posts.

Figure 4-18


• Wire ends may extend beyond the base of the terminal providing minimum electrical spacing is maintained. • Wire passes through the slot and makes positive contact with at least one corner of the post. • Wires/leads 0.75 mm [0.030 in] or larger in diameter are routed straight through the posts. • The number of attachments does not exceed the top of terminal post.

Figure 4-19

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4.7.3.1 Connection Requirements – Bifurcated Terminals – Side Route Attachments (cont.) Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Any portion of the wrap extends above the terminal post. • If wrap is required, minimum wrap is less than 90° around the terminal. • Wire does not pass through slot.

Figure 4-20


• Wire end violates minimum electrical clearance. See 1.12.

Figure 4-21

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4.7.3.2 Connection Requirements – Bifurcated Terminals – Bottom and Top Route Attachments Target - Class 1,2,3

• Wire insulation does not enter base or posts of terminal. • Bottom route wire wrap contacts two parallel sides of post (180°). • Wire is against base of terminal. • Top route wire has space between posts filled by using separate filler or bending the wire double (Figure 4-23 B, C).

Figure 4-22

Figure 4-23 Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Wire insulation enters base or posts of terminal. • Top route wire is not supported with filler. • Bottom route wire not wrapped to terminal base or post with a minimum 90° bend.

Figure 4-24

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4.7.3.3 Connection Requirements – Bifurcated Terminals – Staked Wires As an alternative to wrap requirements of 4.7.3.1, the following criteria apply to wires/leads/components that are staked, bonded or otherwise constrained to provide support for the solder connection.


• Wire terminated with a 90° bend or inserted straight through bifurcated posts or opening in pierced/perforated terminal with mechanical support. • Wire is permanently staked or component body bonded to the board or adjacent surface or constrained by a permanent mounting device. • Wire contacts base of terminal or the previous wire. • Wire extends through posts of bifurcated terminal. • Wire extends beyond the eye of pierced/perforated terminals. Figure 4-25

• Wire contacts two sides of pierced/perforated terminals.

Process Indicator - Class 2 Defect - Class 3

• Wire not staked or component body not bonded to board or adjacent surface or retained by a mounting device prior to soldering. • Wire does not extend through posts of bifurcated terminal or the eye of pierced/perforated terminal. • Wire does not contact base of bifurcated terminal or two sides of pierced/perforated terminal or a previously installed wire.

Figure 4-26

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4-17


4.7.4 Connection Requirements – Slotted Terminals Target - Class 1,2,3

• Lead or wire extends completely through slot and is visible on the exit side. • Wire is in contact with base of terminal area or previously installed wire.

Figure 4-27


• Lead or wire end is discernible on the exit side of terminal. Note: A ‘‘J’’ hook or wrap is not required on a slotted terminal.

Figure 4-28


• Lead end not discernible on exit side of terminal. Defect - Class 1,2,3

• Wire end violates minimum electrical clearance.

Figure 4-29

4-18

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4.7.5 Connection Requirements – Pierced/Perforated/Punched Terminals Target - Class 1,2,3

• Wire passes through the eye of the terminal. • Wire wrapped to contact opposite sides of the terminal. • Insulation clearance one wire diameter.

Figure 4-30

Figure 4-31


• Wire wrap less than 90°. • Wire does not pass through the eye of the terminal (not shown). Defect - Class 2,3

• Terminal altered to accept oversized wire or wire group. • Conductor strands cut or modified to fit into the terminal. Defect - Class 1,2,3 Figure 4-32

• Wire does not contact two sides of the terminal. • Wire end violates minimum electrical clearance to noncommon conductor (not shown). • Wire is fractured at bends (not shown).

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January 2002

4-19


4.7.6 Connection Requirements – Hook Terminals Target - Class 1,2,3

• Wire wrap contacts terminal for a minimum of 180°. • Minimum of one wire diameter space from end of hook to the closest wire. • Wires attached within the 180° arc of the hook. • Wires do not overlap. • Insulation clearance one wire diameter.


• Wire contacts and wraps terminal at least 180°. • No overlap of wire turns. • Minimum of one wire diameter space from end of hook to the closest wire.


• Wire is wrapped less than one wire diameter from end of hook. • Wire wrap is less than 180°. • Wire is attached outside the arc of the hook and is less than two lead diameters or 1.0 mm [0.039 in] whichever is greater from the base of the terminal. Defect - Class 1,2,3

Figure 4-35

4-20

• Wire end violates minimum electrical clearance to noncommon conductor.

January 2002

IPC/WHMA-A-620


4.7.7 Connection Requirements – Cup Terminals Target - Class 1,2,3

• Solder cups having the wire(s) inserted straight in and contact the back wall or other inserted wires for the full depth of the cup.

Figure 4-36


• Wire(s) inserted for full depth of cup, not in contact with back wall and does not interfere with subsequent assembly operations.

Figure 4-38

Defect - Class 2,3

• Solder cup altered to accept oversized wire or wire group. • Wire placement interferes with subsequent assembly operations. • Conductor strands cut or modified to fit into the terminal. Defect - Class 1,2,3

• Strand damage exceeds allowance of Table 3-1.

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4.7.8 Connection Requirements – Series Connected Terminals When a common bus wire connects three or more terminals the end terminals shall meet the required wrap for individual terminals. Solder criteria are based on the individual terminal attachment.

Target - Class 1,2,3

• Stress relief radii between each terminal.

Figure 4-39

• Turrets - Wire contacts base of terminal or a previously installed wire, and wraps around or interweaves each terminal. • Hooks - Wire wraps 360° around each terminal. • Bifurcated - Wire passes between posts and contacts base of terminal or previously installed wire. • Pierced/Perforated - Wire contacts two nonadjacent sides of each terminal.


• Turret Terminals - Wire does not wrap 360° around each inner terminal or is not interwoven between terminals. Figure 4-40

• Hook Terminals - Wire wraps less than 360° around inner terminal. • Bifurcated - Wire does not pass between the posts or is not in contact with the terminal base or a previously installed wire. • Pierced/Perforated - Wire does not contact two nonadjacent sides of each inner terminal. Defect - Class 1,2,3

• No stress relief between any two terminals.

4-22

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4.8 Solder Requirements The preferred conditions of the solder to metal interface, from the physics of wetting, require low or near zero contact angles. Wetting cannot be judged by surface appearance; it can only be inferred by the presence of a low or near zero degree contact angle. A nonwetted condition is normally considered to exist if the solder alloy does not wet parts of the original surface. Normally this implies that the contact angle exceeds 90° (see Figure 4-41). All target solder connections have from a shiny to a satin luster, generally smooth appearance and exhibit wetting as exemplified by a concave meniscus between the objects being soldered. High temperature solders may have a dull appearance. Touch-up (rework) of soldered connections is performed with discretion to avoid causing additional problems, and to produce results that exhibit the acceptability criteria of the applicable class.

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4.8.1 Solder Requirements – General The following general requirements are applicable to all terminals herein unless there is a specific requirement for a given terminal, i.e., 4.8.4.


• Solder fillet appears generally smooth and exhibits good wetting of the solder to the parts/wires being joined. • Outline of the part/wire is easily determined. • Solder at the part/wire being joined has a feathered edge. • Fillet is concave in shape. Figure 4-41


• The acceptable solder connection must indicate evidence of wetting and adherence when the solder blends to the soldered surface, forming a contact angle of 90° or less, except when the quantity of solder results in a contour which is limited by the edge of the attached surfaces. Note: Blowholes, pinholes, voids, etc., are process indicators providing that the solder connection meets the minimum coverage and wetting requirements. Defect - Class 1,2,3

• Nonwetting. • Non-Soldered. • Disturbed solder. • Cold solder. • Fractured. • Insufficient. • Inclusions (foreign material). • Solder that violates minimum electrical clearance (e.g., bridges, solder splashes, solder balls, solder peaks). • Lead or wire extensions that violate minimum electrical clearance. • Contaminated solder connections (e.g., flux residues after cleaning). • Wetting contact angle is greater than 90° except when the quantity of solder results in a contour which is limited by the edge of the attached surfaces.

4-24

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4.8.2 Solder Requirements – Fillet Target - Class 1,2,3

• Solder fillet 100% of the circumference of the wire/lead and terminal interface (full extent of wrap). • Height (climb on wire) of solder is greater than 75% of wire diameter. • Solder wets the wire/lead and terminal and forms a discernible fillet feathering out to a smooth edge. • Wire/lead is clearly discernible in the solder connection. • No blowholes, pinholes or voids. Acceptable - Class 1,2,3

• Solder fillet at least 75% of the circumference of the wire/ lead and terminal interface. • Height (climb on wire) of solder is greater than 50% of wire diameter. • Wire/lead is discernible in solder.

Figure 4-42

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4.8.2 Solder Requirements – Fillet (cont.) Acceptable - Class 1 Process Indicator - Class 2,3

• Wire/lead not discernible in solder connection. • Blowholes/pinholes/voids, etc., providing the solder connection meets minimum requirements. Process Indicator - Class 2 Defect - Class 3

• Height (climb on wire) of solder greater than 25% but less than 50% of wire diameter. Defect - Class 1,2,3

• Poor wetting. • Any evidence of nonwetting to wires or terminals. • Dewetting of either wire or terminal. Defect - Class 1,2

• Height (climb on wire) of solder is less than 25% of wire diameter.

Figure 4-43

4-26

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4.8.3 Solder Requirements – Turret Terminals Target - Class 1,2,3

• Lead outline is discernible, smooth flow of solder on wire and terminal. • Solder fillet at all points of wire/lead and terminal interface (see 4.8.2 and Figure 4-42).

Figure 4-44


• Solder fillet is less than 75% of the circumference of the wire and terminal interface. • Poor wetting. • Acceptance criteria of 4.8.1 and 4.8.2 are not met.

Figure 4-45

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4.8.4 Solder Requirements – Bifurcated Terminals Target - Class 1,2,3

• Lead outline is discernible; smooth flow of solder on wire and terminal. • Solder fillet at all points of wire/lead and terminal interface.

Figure 4-46


• Solder is wetted to at least 75% of the circumference of the wire/lead and terminal interface or 75% of the height for top route wires. Process Indicator - Class 2 Defect - Class 3

• Less than complete wetting where 90° bend is used. Defect - Class 1,2,3

• Acceptance criteria of 4.8.1 and 4.8.2 are not met. • Less than 75% solder height for top route wires. Figure 4-47

4-28

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4.8.5 Solder Requirements – Slotted Terminals Solder should form a fillet with that portion of the lead or wire that is in contact with the terminal. Solder may completely fill the slot but should not be built up on top of the terminal. The lead or wire should be discernible in the terminal.


• Solder forms a fillet with that portion of the lead or wire that is in contact with the terminal. • There is visible insulation clearance.

Figure 4-48


• Solder fills terminal slot. • Lead or wire end is discernible in the solder on the exit side of terminal.

Figure 4-49


• Lead end not discernible on exit side of terminal. Defect - Class 1,2,3

• Wire end violates minimum electrical clearance.

Figure 4-50

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4.8.6 Solder Requirements – Pierced/Perforated Terminals Target - Class 1,2,3



• Solder fillet joins the wire to the terminal for at least 75% of the wire and terminal contact. Process Indicator - Class 2 Defect - Class 3

• Less than 100% wetting of terminal/wire interface where 90° bends are used.

Figure 4-52


• Solder dewetted from terminal or wire/lead. • Solder contact angle greater than 90°. • Acceptance criteria of 4.8.1 and 4.8.2 are not met.

Figure 4-53

4-30

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4.8.7 Solder Requirements – Hook Terminals Target - Class 1,2,3


Figure 4-54


• Solder fillet joins the wire to the terminal for at least 75% of the wire and terminal contact.

Figure 4-55


• Does not exhibit a solder fillet joining the wire to the terminal for at least 75% of the wire and terminal contact. • Wetting contact angle is greater than 90° except when the quantity of solder results in a contour which is limited by the edge of the attached surfaces. • Acceptance criteria of 4.8.1 and 4.8.2 are not met.

Figure 4-56

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4.8.8 Solder Requirements – Cup Terminals Target - Class 1,2,3

• Solder wets the entire inside of the cup. • Solder fill is 100%. • Outside of cup free of solder. Acceptable - Class 1,2,3

• Thin film of solder on the outside of the cup. • Solder fill greater than 75%. • Solder buildup on the outside of the cup that does not affect form, fit, function or reliability.

Figure 4-57

Defect - Class 2,3

• Solder buildup on the outside of the cup negatively affects form, fit, function or reliability (Figure 4-58). • Solder vertical fill less than 75% (Figure 4-59).

Figure 4-58

Figure 4-59

4-32

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5 Crimp Terminations

Crimp Terminations

A critical element of any wire termination is the connection between the wire and the contact. Crimping of terminal contacts is one method of achieving this connection.

requirements and instructions. All crimped terminations need to meet industry requirements, such as EIA, IEC, NEMA, UL or other as designated.

A good termination both ensures mechanical integrity and meets electrical requirements for the application.

The following topics are addressed in this section:

In addition to the basic requirements outlined in this section, there should also be no damage to plating or finish, no contact deformation that would cause friction or increase force to insert or load the contact into the connector body, and no contact deformation that does not allow all contact locking tabs or wings to fully engage and lock into the connector body. Conductors should not be cut or modified in any manner in order to fit into the contact. Conductors should not be tinned prior to termination, unless otherwise specified.

5.1.1 5.1.2 5.1.3 5.1.4 5.1.5 5.1.6

Insulation Support Crimp Insulation Inspection Window Conductor Crimp Crimp Bellmouth Conductor Brush Carrier Cutoff Tab

5.2 Machined Crimp Contacts

5.2.1 5.2.2 5.2.3 5.2.4 5.2.5

Insulation Clearance Insulation Support (Insulation Support Style Contacts) Conductor Location Crimping Under Size Conductor - CMA Buildup Crimps

January 2002

5-1

All crimping needs to comply with the manufacturers’ published requirements, i.e., crimp height, pull test, etc., without regard to the specific tooling used. For complete understanding, refer to applicable connector or terminal manufacturer’s

IPC/WHMA-A-620

5.1 Stamped and Formed Contacts


5.1 Stamped and Formed Contacts Criteria for insulated lugs is included. There are different configurations for insulation support and crimp areas and for the conductor crimp. Additionally, there may be an outer insulator over part or all of the crimp area. Figures 5-1 and 5-2 identify the component parts of typical stamped and formed contacts. When attaching multiple wires to a single terminal, each wire is to meet the same acceptability criteria as a single wire termination. The attachment of a single wire or combination of multiple wires attached to a terminal/contact must meet the manufacturer’s specifications for a single wire i.e., total wire area may not exceed the circular mil area for the terminal specified.

Figure 5-2 1. 2. 3. 4. 5. 6. 7. 8. 9.

Insulation inspection window Bellmouth Brush inspection window Locking tab/tang Insulation crimp area Conductor crimp area Terminal mating area Cut off tab (may be at either end of terminal) Terminal stop ear

Figure 5-1

5-2

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5.1.1 Stamped and Formed Contacts – Insulation Support Crimp Target - Class 1,2,3

• Insulation fully enters and extends past the insulation crimp tabs. • If multiple wires are used insulation from all wires extend past the insulation crimp tabs. • Insulation crimp does not cut or break insulation. • Insulation crimp tabs fully wrap and support insulation. • For insulated lugs, the insulation crimp is evenly formed and contacts the wire insulation providing support without damaging the insulation (Figure 5-5).

Figure 5-3

Figure 5-4


• Puncturing of the insulation surface by the insulation crimp tabs, provided that the tabs do not penetrate down to the conductor.

Figure 5-6

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5-3


5.1.1 Stamped and Formed Contacts – Insulation Support Crimp (cont.) Acceptable - Class 2,3

• Minor deformation of the insulation surface as long as the insulation crimp tabs do not cut, break, penetrate or puncture the surface of the wire insulation. • Insulation crimp tabs provide a minimum side support of 180° to the wire insulation and both tabs contact the top of the wire insulation. • Insulation rimp tabs do not meet at the top, but encircle the wire leaving an opening of 45° or less at the top. • The outer insulation sleeve on insulated terminals shall remain secured to the terminal after crimping.

Figure 5-7


• For insulated terminals, irregular shaped insulation crimp contacts the wire insulation providing support without damaging the insulation (Figures 5-8 and 5-9).

Figure 5-8

Figure 5-9

5-4

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5.1.1 Stamped and Formed Contacts – Insulation Support Crimp (cont.) Defect - Class 1,2,3

• The insulation crimp tabs pierce the insulation penetrating down to the conductor (Figure 5-10). • The insulation crimp tabs do not provide support at least 180° around the insulation (Figure 5-11). • Crimp tabs that encircle the wire but leave an opening of more than 45° at the top (Figure 5-12). • Both insulation crimp tabs are not in contact with the top of the insulation (Figure 5-13). • Conductors are in insulation crimp area of the contact (Figures 5-14, 5-15). Figure 5-10

Figure 5-11

Figure 5-12

Figure 5-13

Figure 5-14

Figure 5-15

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5.1.2 Stamped and Formed Contacts – Insulation Inspection Window Figure 5-16 identifies the insulation inspection window.


• Insulation and conductor transition line centered within the inspection window.

Figure 5-16


• Insulation is flush with but does not enter the wire crimp area (1). • Insulation is flush with the inspection window edge of the insulation crimp tabs and does not enter the inspection window area (2).

Figure 5-17

Acceptable - Class 2,3

• Both insulation and conductor are visible within the inspection window.

Figure 5-18

5-6

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5.1.2 Stamped and Formed Contacts – Insulation Inspection Window (cont.) Defect - Class 1,2,3

• Insulation extends into conductor crimp area (Figure 5-19, arrow points to end of insulation within the crimp area). • Insulation and conductor transition line is within insulation crimp area (Figure 5-20, arrow points to end of insulation within the crimp area).

Figure 5-19

Figure 5-20

5.1.3 Stamped and Formed Contacts – Conductor Crimp Figure 5-21 identifies the conductor crimp area.


• No insulation in the conductor crimp area. • Conductor extends to the middle of the brush area. • No conductor strands broken, folded back into crimp area, or not captured by the conductor crimp tabs. • Crimp centered on the conductor crimp area with correct bellmouth. Figure 5-21

• Crimp indentations uniform and meet contact/tooling manufacturer’s requirements. • No deformation of contact such as a banana shape after crimping. • Locking tabs in place with no signs of deformation or damage. • Conductor strands not twisted, cut or modified to fit into the terminal.

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5-7


5.1.3 Stamped and Formed Contacts – Conductor Crimp (cont.) Acceptable - Class 1,2,3

• No insulation in the conductor crimp area. • The conductor end (and filler wire if specified) is visible within brush inspection window. • No conductor strands broken, folded back into crimp area, or not captured by the conductor crimp tabs. • Crimp indentations uniform and meet contact/tooling manufacturer’s requirements. • Minor deformation of contact such as a banana shape that does not affect form, fit, function or reliability. • Locking tabs in place with no signs of deformation or damage. • Filler wire, if specified, is within insulation crimp and does not extend beyond the edge of the lug insulation. Figure 5-22

• If drawings require foldback of conductor in the crimp area, the fold is visible in the brush area and the cut end is visible at the entry bellmouth. Acceptable - Class 1,2 Process Indicator - Class 3

• Minor deforming of the contact does not alter its form, fit, function or reliability. Note: A trial mating may be required for final acceptance.


• Conductor is flush to end of conductor crimp area. • Crimp indentations not uniform but do not affect form, fit, function or reliability.

Figure 5-23

5-8

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5.1.3 Stamped and Formed Contacts – Conductor Crimp (cont.) Acceptable - Class 1 Defect - Class 2,3

• Filler wire extends beyond edge of the lug insulation.

Figure 5-24 Defect - Class 1,2,3

• Insulation extends into conductor crimp area (Figure 5-25, arrow points to end of insulation within the crimp area). • Conductor does not extend out of the crimp area and is not visible within the brush-end bellmouth (Figure 5-26 and Figure 5-28). • Deformation (banana) of the contact/terminal that affects form, fit, function or reliability (Figure 5-27).

Figure 5-25

• Any loose conductor strands that are outside the crimp area, trapped strands, folded back strands (Figure 5-29).

Figure 5-26

Figure 5-27

Figure 5-28

IPC/WHMA-A-620

Figure 5-29

January 2002

5-9


5.1.4 Stamped and Formed Contacts – Crimp Bellmouth The bellmouth areas identified in Figure 5-30 are considered to be part of the conductor crimp area.

Figure 5-30 1. Entry bellmouth 2. Brush-end bellmouth


• Bellmouth at each end of the conductor crimp area. • Bellmouth height at the conductor entry end is 2X the thickness of the contact/terminal base metal.

Figure 5-31 1. Metal thickness 2. Bellmouth height 2X metal thickness


• Bellmouth only at the conductor entry end (1) and not at the conductor brush end of the crimp (2). • Bellmouth at conductor entry is visible but less than 2X the thickness of the metal.

Figure 5-32 1. Conductor entry bellmouth 2. Brush-end bellmouth

5-10

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5.1.4 Stamped and Formed Contacts – Crimp Bellmouth (cont.) Defect - Class 1,2,3

• No visible bellmouth at the conductor entry end of the crimp (1). • Excessive bellmouth indicating over crimping or undersize wire gauge (2).

Figure 5-33 1. Conductor entry bellmouth 2. Brush-end bellmouth

5.1.5 Stamped and Formed Contacts – Conductor Brush Figure 5-34 identifies the conductor brush area.


• The conductor strands protrude slightly past the end of the conductor crimp forming a ‘‘conductor brush.’’ • The conductor strands forming the brush are kept together as a group and not flared out.

Figure 5-34

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5.1.5 Stamped and Formed Contacts – Conductor Brush (cont.) Acceptable - Class 1 Process Indicator - Class 2,3

• Conductor strands not protruding past but flush with the end of the conductor crimp area of the contact (Figure 5-35 (1)). Acceptable - Class 1,2,3

• Conductor strands flared out but not extending outside of the contact (Figure 5-35 (2)). • Conductor strands extend past the end of the crimp of insulated terminal.

Figure 5-35

Figure 5-36

5-12

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5.1.5 Stamped and Formed Contacts – Conductor Brush (cont.) Acceptable - Class 1 Defect - Class 2,3

• Any conductor strands extending outside of the contact (Figures 5-37, 5-38). • The conductor strands extend into the mating area of the contact (Figures 5-39, 5-40). Defect - Class 1,2,3

• Outer insulation of insulated terminal is damaged exposing metal (Figure 5-40).

Figure 5-37

Figure 5-38

Figure 5-39

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Figure 5-40

January 2002

5-13


5.1.6 Stamped and Formed Contacts – Carrier Cutoff Tab Figure 5-41 identifies a carrier cutoff tab at the wire entry end. It is located at the mating end of some terminal types.


• No damage to contact or terminal. • Cutoff does not prevent complete mating of the contact/ terminal. Process Indicator - Class 2,3

• Cutoff tab length at mating end is greater than 2X its thickness but does not impede mating. • Cutoff tab length at wire entry end is greater than 2X its thickness but does not protrude when inserted into connector body. Figure 5-42


• Carrier cutoff tab length is greater than 2X its thickness (Figure 5-43). • Removal of cutoff tab has damaged contact or terminal. • Cutoff tab protrudes from connector body when contact has been inserted. • Mating end cutoff tab prevents complete mating. • No carrier cutoff tab visible and contact/terminal is damaged.

Figure 5-43

5-14

Note: Contact/terminal needs to meet form, fit, function and reliability requirements. A trial mating may be required for final acceptance.

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5.2 Machined Crimp Contacts These criteria are also applicable to closed barrel stamped insulated and uninsulated lugs and terminals.

5.2.1 Machined Crimp Contacts – Insulation Clearance Figure 5-44 defines the parts of a machined crimp contact. See 5.2.2 for machined crimp contacts - insulation support style criteria.

Figure 5-44 1. Insulation clearance 2. Conductor crimp area 3. Inspection window


• 50% overall wire diameter (D) clearance (C) between the insulation and contact barrel.

Figure 5-45

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5.2.1 Machined Crimp Contacts – Insulation Clearance (cont.) Acceptable - Class 2,3

• Conductor is visible between the insulation and contact barrel but no greater than one wire diameter (Figure 5-46). Acceptable - Class 1 Process Indicator - Class 2,3

• Insulation is flush to the end of the contact barrel (not shown).

Figure 5-46


• Insulation is greater than one but less than two wire diameters from the end of the contact barrel (Figure 5-47).

Figure 5-47 Defect - Class 2,3

• Insulation is greater than two wire diameters from the end of the contact barrel (Figure 5-48). Defect - Class 1,2,3

• Exposed conductor violates minimum electrical clearance. • Insulation enters barrel of terminal (Figures 5-49, 5-50).

Figure 5-48

Figure 5-49

5-16

Figure 5-50

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5.2.2 Machined Crimp Contacts – Insulation Support (Insulation Support Style Contacts) Figure 5-51 defines the parts of an insulation support style machined crimp contact.

Figure 5-51 1. Insulation support barrel 2. Insulation funnel

3. Inspection window


• Wire insulation seated in the insulation support entry funnel (Figure 5-52). Acceptable - Class 1,2,3

• Wire insulation enters insulation support barrel (Figure 5-53).

Figure 5-52


• Wire insulation not inserted into the insulation support barrel of the contact.

Figure 5-54

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5.2.3 Machined Crimp Contacts – Conductor Location This section is applicable to all machined crimp contacts.


• Conductor bottomed in the contact. • Conductor strands fill the inspection window. • No conductor strands outside of the contact.

Figure 5-55


• Conductor partially visible in the inspection window. • No conductor strands outside of the contact.

Figure 5-56

5-18

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5.2.3 Machined Crimp Contacts – Conductor Location (cont.) Defect - Class 1,2,3

• Conductor strands not visible in the inspection window of the contact (Figure 5-57). • Insulation visible in the inspection window of the contact (Figure 5-58). • Conductors twisted together before insertion into the contact (Figure 5-59). • Any conductor strands outside of the conductor crimp area (Figure 5-60).

Figure 5-57

Figure 5-58

Figure 5-59

IPC/WHMA-A-620

Figure 5-60

January 2002

5-19


5.2.4 Machined Crimp Contacts - Crimping The crimp area is defined as the area between the wire entry end of the contact and the closest edge of the inspection window.


• Crimp indent is centered between the inspection window and the wire entry end of the barrel. • Crimp indents around the contact barrel are evenly spaced and of equal depth. • No loose wire strands. • Contact has no visible fractures, cracks, or exposed base metal.

Figure 5-61


• The crimp indent is outside the crimp area. • Wire entry end of the barrel is deformed by the crimp.

Figure 5-62

Figure 5-63

5-20

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5.2.4 Machined Crimp Contacts - Crimping (cont.) Acceptable - Class 2,3

• The crimp is not centered and the inspection window is not deformed. • The wire entry end of the barrel is not deformed by the crimp.

Figure 5-64

Defect - Class 2,3

• The crimp touches the top edge of the inspection window. • Contact has exposed base metal.

Figure 5-65


• Wire is not secured by crimp. • Contact has visible fracture or cracks. • Double crimping of electrical terminations or connector contacts unless otherwise specified. • Contact barrel is deformed or bent.

Figure 5-66

Figure 5-67

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5.2.5 Machined Crimp Contacts – Under Size Conductor – CMA Buildup Crimps Circular mil area (CMA) is not to be built up unless specified on design drawings.


• The circular mil area of the conductor is built up so that it falls within the minimum and maximum CMA range of the contact. • The CMA range is built up using one of the methods listed below: • The conductor is folded or bent back to achieve the correct CMA buildup.

Figure 5-68

• The conductor area is increased by the use of bare (noninsulated) filler conductors as needed to achieve the correct CMA buildup. • A combination of both the foldback and the filler method are used to achieve the correct CMA buildup. • Special ‘‘CMA Adapter Bushings’’ are used when called out on the assembly documentation. (Use of these adapters will usually require special additional insulating coverage requirements.) • The filler is visible at the wire entry end of the barrel. Acceptable - Class 1,2,3

• The filler conductors and the wire conductor are visible in the inspection window of the contact. Figure 5-69

5-22

• The filler conductor is of the same type conductor as the wire being crimped into the contact. (Gauge can be different as needed but the base metal and the plating if any needs to be the same.)

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IPC/WHMA-A-620


5.2.5 Machined Crimp Contacts – Under Size Conductor – CMA Buildup Crimps (cont.) Defect - Class 1,2,3

• A single solid conductor used to build up the CMA. • The filler conductors and/or the wire conductor are not visible in the inspection window.

Figure 5-70

Defect - Class 2,3

• Fill wire extends beyond the insulation of the primary wire.

Figure 5-71


• The flair or splay of conductor used extends past or exceeds the contact diameter. • Exposed conductor violates minimum electrical clearance.

Figure 5-72

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5-23



5-24

January 2002

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6 Insulation Displacement Connection (IDC)

Insulation Displacement Connection (IDC) Insulation displacement connection (IDC), sometimes referred to as insulation displacement termination (IDT) is a method for terminating an insulated wire to a connector or terminal without pre-stripping the insulation from the conductor. However, this method may be used for an uninsulated wire as well. It is recognized that this technology is utilized by a significant number of different connector types. This section attempts to define common acceptance criteria regardless of the connector type. It is extremely important to recognize that the wire, the connector, and the assembly process are compatible, as normally specified by the connector manufacturer. Variations in wire gauge, wire-to-wire spacing (for multiple conductor flat or ribbon cable), insulation thickness, insulation type, application tooling, or alignment of the cable to the connector may result in an unreliable connection or in an electrical open or short circuit. It is also recognized that in some insulation displacement products, visual inspection of the wire/termination connection is not possible without destructive analysis.

IPC/WHMA-A-620

The following topics are addressed in this section: 6.1 Mass Termination, Flat Cable

6.1.1 6.1.2 6.1.3 6.1.4 6.1.5 6.1.6

End Cutting Notching Planar Ground Plane Removal Connector Position Connector Skew & Lateral Position Retention

6.2 Discrete Wire Termination

6.2.1 6.2.2 6.2.3 6.2.4 6.2.5 6.2.6 6.2.7 6.2.8 6.2.9

January 2002

General Position of Wire Overhang (Extension) Wire Holder Damage in Connection Area End Connectors Wiremount Connectors Subminiature D-Connector (Series Bus Connector) Modular Connectors (RJ Type)

6-1


6.1 Mass Termination, Flat Cable

6.1.1 Mass Termination, Flat Cable – End Cutting Target - Class 1,2,3

• The cable is cut perpendicular to the cable edge. • Cable is cut straight with no visible variation (wave or unevenness). • No conductor strands protrude beyond the insulation of the cable.

Figure 6-1


• The cable end is cut so that it allows compliance to all other assembly requirements. • Conductor protrusion from the end of the cable ≤50% diameter of the conductor.

Figure 6-2


• Uneven or wavy cutting of the cable end precludes compliance to any other assembly requirement. • Conductor protrusion from the end of the cable >50% diameter of the conductor.

Figure 6-3

6-2

January 2002

IPC/WHMA-A-620


6.1.2 Mass Termination, Flat Cable – Notching Target - Class 1,2,3

• The connector mounting notches are cut parallel to the conductors and does not reduce the wire insulation. • The notch length and width allows correct connector mounting including strain relief clips or covers if used. Acceptable - Class 1,2,3

• Variations in parallelism of the notch do not interfere with the mounting and crimping of the connector or reduce conductor insulation. • Tooling marks do not break the surface of the insulation. Figure 6-4


• Notching that cuts, nicks or exposes the conductors. • Variations in parallelism of the notch interfere with the mounting and crimping of the connector or reduce conductor insulation. • Tooling marks break the surface of the insulation.

Figure 6-5

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January 2002

6-3


6.1.3 Mass Termination, Flat Cable – Planar Ground Plane Removal Target - Class 1,2,3

• Planar ground screen removed prior to installing and crimping an IDC connector to the cable. • No insulation damage such as cuts or nicks. Acceptable - Class 1,2,3

• Minor tooling marks that do not break the surface of the insulation.

Figure 6-6


• Planar ground screen not removed from connector crimp area. • Nicked or cut insulation after removal of the planar ground screen layer. • Connector crimped on any portion of the cable that has not had the planar ground screen removed.

Figure 6-7

6-4

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6.1.4 Mass Termination, Flat Cable – Connector Position Target - Class 1,2,3

• Cut end of the cable is flush with the outside edge of the connector body. • The connector cover is fully compressed to the connector body along its entire length. • Cover hold down latches are fully engaged and latched. • Cable foldback inside radius, if applicable, is two cable thicknesses.


• The cable end is flush or extends beyond the outside edge of the connector one cable thickness or less and does not violate minimum electrical clearance • Minor tooling marks that do not break the surface of the insulating material of the connector or cable. • Cable foldback inside radius, if applicable, is flush with connector body and does not interfere with installation of the connector.

Figure 6-8

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January 2002

6-5


6.1.4 Mass Termination, Flat Cable – Connector Position (cont.) Defect - Class 1,2,3

• Cover hold down latches are not fully engaged and latched (Figure 6-9). • Any broken cover hold down latches or barbs (not shown). • Cable does not extend into IDC contacts for all wires (not shown). • Exposed wires violate minimum electrical clearance (not shown). • Cable foldback, if applicable, interferes with mechanical fit of the connector (Figure 6-10). Acceptable - Class 1 Defect - Class 2,3 Figure 6-9

• Cable extends beyond the edge of the connector greater than one thickness of cable (Figure 6-11).

Figure 6-10

Figure 6-11

6-6

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6.1.5 Mass Termination, Flat Cable – Connector Skew and Lateral Position Target - Class 1,2,3

• Connector is aligned perpendicular to the edge of the flat cable. • Cable end is flush along the entire length of the outside edge of the connector. • All conductors are centered within the v-notch of the connector contacts. Acceptable - Class 1,2,3

• Connector is aligned so that all conductors are centered in their respective v-notches of the cable.

Figure 6-12


• Connector misalignment precludes contact of all wires to the IDC contacts. • Connector misalignment permits shorting of conductors in the IDC contact area. • Connector misalignment precludes assembly of connector cover. • Connector misalignment causes wire damage during crimping. • Face of the cable is not parallel to the face of the connector (Figure 6-14).

Figure 6-13

Figure 6-14

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January 2002

6-7


6.1.6 Mass Termination, Flat Cable – Retention Acceptable - Class 1,2,3

• Wires are retained in the connector. • Strain relief features of the connector, if applicable, are utilized. • Where present, connector-locking tabs are properly engaged.

Figure 6-15


• Wires are not retained in the connector (Figure 6-16). • Strain relief features of the connector, if applicable, are not utilized. • Where present, connector-locking tabs are not engaged (Figure 6-17).

Figure 6-16

Figure 6-17

6-8

January 2002

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6.2 Discrete Wire Termination

6.2.1 Discrete Wire Termination – General Figure 6-18 shows construction of an insulation displacement connection. Only accepted materials and appropriate equipment and methods shall be used in insulation displacement connections. Insulation displacement connections shall not be mechanically stressed after making the connection, e.g., the connection must not be ‘‘repaired’’ afterwards by moving the wire or the mechanics of the slot. Figure 6-19 is an example of connector tab.

Figure 6-18

Figure 6-19

1. Electrical slot 2. Mechanical slot 3. Connection area

1. Dual cantilever contact 2. Contact points 3. Electrical contact

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January 2002

4. Mechanical contact 5. Strain relief

6-9


6.2.2 Discrete Wire Termination – Position of Wire Target - Class 1,2,3

• Connection area of the wire is in the center in the connection area of the slot. Acceptable - Class 1,2,3

• Connection area of the wire is completely in the connection area of the slot.

Figure 6-20


• Connection area of the wire is not completely in the connection area of the slot in both the front and back wire slots of a dual slot contact. • Conductor is not completely within the connection area of the slot.

Figure 6-21

Figure 6-22

6-10

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6.2.3 Discrete Wire Termination – Overhang (Extension) These criteria are not applicable to pass-through IDC connectors.


• Overhang (L) of the wire extends to the far edge of the IDC connectors. Acceptable - Class 1

• Wire end is flush with electrical (second) contact. Acceptable - Class 2,3

• Overhang of L of the wire is equal or greater than 50% overall wire diameter.

Figure 6-23


• Wire does not pass through both IDC contacts. • Exposed conductors violate minimum design electrical clearance.

Figure 6-24

Figure 6-25

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January 2002

6-11


6.2.3 Discrete Wire Termination – Overhang (Extension) (cont.) Defect - Class 2,3

• Overhang L of the wire is less than 50% overall wire diameter (Figure 6-26). • Wire is deformed and extends out of the connector (Figure 6-27).

Figure 6-26

Figure 6-27

6-12

January 2002

IPC/WHMA-A-620


6.2.4 Discrete Wire Termination – Wire Holder The requirements of 5.2.1 Insulation Support Crimp also applies.


• Both holders bent snug to insulation. • Maximum height of the holders is below the top of the housing.

Figure 6-28


• Wire is contained (space is permitted between insulation and holders).

Figure 6-29

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January 2002

6-13


6.2.4 Discrete Wire Termination – Wire Holder (cont.) Defect - Class 2,3

• Both crimp tabs are not crimped to prevent the wire escaping the holders. • Crimp tabs violate electrical isolation distance. • Crimp tabs pierce insulation.

Figure 6-30

Figure 6-31

6-14

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6.2.5 Discrete Wire Termination – Damage in Connection Area Target - Class 1,2,3

• There is no damage in the construction of the slot(s) on the circled area shown in Figure 6-32.

Figure 6-32 Acceptable - Class 2,3

• Minor deformation not piercing wire insulation on both sides of the slots. • Minor damage in the holder tabs does not affect functionality.


• Tool damage on the connection area. • Slot(s) twisted, bent or otherwise damaged. • Corrosion damage or other detrimental impurities on the surface of the slot.

Figure 6-34

• Plating of holder damaged so that the base metal is exposed. • Contact damage that causes the side beams of the wire slot to not be parallel with each other.

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January 2002

6-15


6.2.6 Discrete Wire Termination – End Connectors Target - Class 1,2,3

• Wire fully seated into the contact. • Wire extends at least 50% of the distance between the contact edge and the back wall of the connector.

Figure 6-35


• Wire touches back wall with slight deformation but the top of the wire does not rise above the back wall. • Portions of bare conductor are visible but no bare conductor extends outside the connector body. • Exposed conductors do not violate minimum design electrical clearance.

Figure 6-36

6-16

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6.2.6 Discrete Wire Termination – End Connectors (cont.) Defect - Class 1,2,3

• Wire stripped or partially stripped before being inserted into the connector. • Wire not within retaining barbs. • Two wires into a single contact unless the contact or connector specifications indicate that this is acceptable. • Deformation of the connector body due to wires with oversize insulation. • Insufficient stress relief on wires entering connector. • Wire size does not meet connector parameters.

Figure 6-37

• Wire not fully seated in both sets of v-notches of the IDC contact. • The wire extends less than one wire diameter out of the rear contact. • Broken retaining barbs on the connector.

Figure 6-38

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6-17


6.2.7 Discrete Wire Termination – Wiremount Connectors Target - Class 1,2,3

• Connector perpendicular in relation the cable/wire centerline.


• Contact not at 90° in relation to the wire centerline and this position does not cause any wire stress. • Wire position is within the wire connection area (see 6.2.2).


• Wire stripped or partially stripped before being inserted into the connector (not shown). • Wire not within retaining barbs (A and G). • Wire not fully seated in both sets of v-notches of the IDC contact (A and E). • Wire size does not meet connector parameters (not shown). • Two wires into a single contact unless the contact or connector specifications indicate that this is acceptable (not shown). Figure 6-41

• Deformation of the connector body due to wires with oversize insulation (not shown). • Insufficient stress relief on wires entering connector (not shown). • Broken retaining barbs on the connector (G).

6-18

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IPC/WHMA-A-620


6.2.8 Discrete Wire Termination – Subminiature D-Connector (Series Bus Connector) Target - Class 1,2,3

• Wire ends flush with termination cover plates or extend less than 0.5 mm [0.02 in].

Figure 6-42


• Wire may extend to the end of free space.

Figure 6-43

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January 2002

6-19


6.2.8 Discrete Wire Termination – Subminiature D-Connector (Series Bus Connector) (cont.) Defect - Class 1,2,3

• Wire recessed (Figure 6-44). • Wire is bent upwards in the free space over the top of the connector body (Figure 6-45). • Termination cover plate is broken or deformed (Figure 6-46, 47). • Contact base metal is exposed (not shown). • Contact is bent after termination and does not fit within the termination cover slots (not shown).

Figure 6-44

• Covers are not fully seated against connector housing at cover ends or cover is clearly convex at the center (not shown).

Figure 6-45

Figure 6-46

6-20

Figure 6-47

January 2002

IPC/WHMA-A-620


6.2.9 Discrete Wire Termination – Modular Connectors (RJ Type) The following criteria apply to Type RJ telecommunications connectors with or without loading bar.


• All wires are bottomed in connector and visible through the front of the connector. • The primary strain relief is crimped tightly against the cable jacket. • The cable jacket extends past the point of the strain relief. • For connector without a loading bar, the secondary strain relief is crimped so that it is in contact with the insulation. • The contacts are crimped so that no part of the contacts are above the plane created by the top of the plastic dividers between the contacts. Acceptable - Class 1,2,3

• Wires are not bottomed but all are within 0.5 mm [0.02 in] or less of the end wall but all are inserted at least past the terminal. • Contacts meet the connector manufacturers crimp height specification.

Figure 6-48 1. 2. 3. 4.

Loading bar Wire end clearance Secondary strain relief Primary strain relief


• The primary strain relief is not in tight contact against the cable jacket or is not latched. • The cable jacket does not extend past the primary strain relief. • Wire ends are not within 0.5 mm [0.02 in] or less of the contact end wall. or are not inserted past the terminal. • All wire ends are not visible through the face of the connector. • Connector without loading bar the secondary strain relief is not in contact with the wires or is not latched. • The contacts are not crimped sufficiently and extend above the plane created by the top of the plastic dividers between the contacts.

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January 2002

6-21



6-22

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7 Ultrasonic Welding

Ultrasonic Welding The following topics are addressed in this section: 7.1 Insulation Clearance 7.2 Weld Nugget

7.2.1 Geometry

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January 2002

7-1


7.1 Insulation Clearance Target - Class 1,2,3

• End of Insulation is between one and two wire diameters from weld nugget.


• Insulation is embedded in weld nugget. • Insulation gap is so large that it causes the conductor to violate minimum electrical spacing.


• End of insulation is less than one wire diameter or more than two wire diameters from weld nugget.

Figure 7-3

7-2

January 2002

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7.2 Weld Nugget

7.2.1 Weld Nugget – Geometry


• Nugget width to height ratio is 1.5 to 1. • Individual wire strands are not distinguishable on compression surfaces (top & bottom) of nugget.

Figure 7-4


• Nugget width to height ratio is more than 1 to 1 but does not exceed 2 to 1.

Figure 7-5

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January 2002

7-3


7.2.1 Weld Nugget – Geometry (cont.) Acceptable - Class 1, Process Indicator - Class 2,3

• Individual wire strands are distinguishable on compression surfaces, but there are no loose strands.

Figure 7-6

Defect - Class 2, 3.

• Any loose wire strands.

Figure 7-7

Defect - Class 1, 2, 3

• Any discoloration of the conductors.

Figure 7-8

7-4

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8 Splices

Splices The following topics are addressed in this section. 8.1 Soldered Splices

8.1.1 8.1.2 8.1.3 8.1.4

Mesh Wrap Hook Lap

8.2 Splices - Crimped

8.2.1 Barrel 8.2.2 Double Sided 8.3 Splices - Ultrasonic Welded

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January 2002

8-1

8 Splices

8.1 Soldered Splices Using splices to repair broken or damaged conductors are not permitted for Classes 2 and 3 without end-user concurrence prior to the repair. For solder and cleanliness requirements, see 1.18 and 4.

8.1.1 Soldered Splices – Mesh Acceptable - Class 1,2,3

• Interlocking of conductive strands into a smooth joined section for a minimum of three but not more than five wire diameters. Figure 8-1

• Insulation covers splice and overlaps wire insulation a minimum of one wire diameter. • No conductive strands piercing the insulation.

Figure 8-2


• Wire bulges the insulation but does not pierce it.

Figure 8-3


• There are sharp points or projections. • Conductive strands pierce the insulation. • Wire splice area is exposed. Figure 8-4

• Insulation does not overlap wire splice area for a minimum of one wire diameter.

Figure 8-5

8-2

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8 Splices

8.1.2 Soldered Splices – Wrap The contact area between the two wires shall be a minimum of three wraps (not twists) of each wire around the other.


• Interlocking of two wire strands into a smooth joined section for a minimum of three wraps of each conductor. • No conductive strands piercing the insulation. Figure 8-6

• Insulation covers splice and overlaps wire insulation a minimum of one wire diameter (not shown).



Figure 8-7


• There are sharp points or projections. • Conductor strands pierce the insulation. • Wire splice area is exposed. Figure 8-8

• Insulation does not overlap wire splice area for a minimum of one wire diameter. • Less than three wraps of each conductor.

Figure 8-9

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January 2002

8-3

8 Splices

8.1.3 Soldered Splices – Hook The contact area between the two wires shall be a minimum of three wraps (not twists) of each wire around the other.

Acceptable - Class 1,2,3 3 Wraps Min.

• Interlocking of two wire strands into a smooth joined section for a minimum of three wraps. • No conductive strands piercing the insulation. • Insulation covers splice and overlaps wire insulation a minimum of one wire diameter (not shown).

Figure 8-10

• Conductive strands form a smooth joined section. • Conductive strands are covered with insulation.




• Wire splice area is exposed. • Insulation does not overlap wire splice area for a minimum of one wire diameter. Figure 8-12


• There are sharp points or projections. • Conductor strands pierce the insulation. • Less than three wraps of each conductor. Figure 8-13

8-4

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8 Splices

8.1.4 Soldered Splices – Lap Acceptable - Class 1,2,3

• Wires are parallel for at least three but not more than five wire diameters. • Conductive strands form a smooth joined section. Figure 8-14

• Insulation covers splice and overlaps wire insulation a minimum of one wire diameter. • No conductive strands piercing the insulation.

Figure 8-15



Figure 8-16


• There are sharp points or projections. • Conductor strands pierce the insulation. • Wires not parallel at least three wire diameters. Figure 8-17

• Wire splice area is exposed.

Figure 8-18

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January 2002

8-5

8 Splices

8.2 Splices – Crimped

8.2.1 Splices – Crimped – Barrel Target - Class 1,2,3

• Wire insulation is flush against end of barrel splice (A). • Bare wire ends are flush with barrel splice, bellmouth is evident (B). • Crimp is centered and properly formed to retain wires (C). • Barrel splice is not cracked. • Sleeving extends past the bare wire conductors 6 mm [0.25 in] minimum on both sides of the barrel splice (not shown).

Figure 8-19


• Wire insulation gap is within two wire diameters (A). • Bare wire end is less than flush, but is visible and included in crimp indentation (B). • Crimp slightly offset but properly formed, bellmouth is evident (C). • Barrel splice is not cracked. • Sleeving extends past the (D) bare wire conductors 6 mm [0.25 in] minimum on both sides of the barrel splice (not shown). • Does not violate minimum electrical clearance. Figure 8-20

8-6

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8 Splices

8.2.1 Splices – Crimped – Barrel (cont.) Acceptable - Class 1,2 Process Indicator - Class 3

• Bare wire ends extend no more than two wire diameters including insulation.

Figure 8-21

Acceptable - Class 1,2 Process Indicator - Class 3

• Crimp not correctly positioned but bellmouth is evident.

Figure 8-22


• Insulation gap exceeds two wire diameters. • Wire ends protrude greater than two wire diameters. • Insulation extends into barrel splice crimp (not shown).

Figure 8-23

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January 2002

8-7

8 Splices

8.2.1 Splices – Crimped – Barrel (cont.) Defect - Class 1,2,3

• Barrel splice is cracked (Figure 8-24 arrow). • Crimp indentation is off the end of the barrel splice, bell mouth is evident. • Wires are not contained in the crimp.

Figure 8-24

8.2.2 Splices – Crimped – Double Sided Target - Class 1,2,3

• Ends of wires are visible through the inspection window and are flush to the wire stop (A) (B). • Bellmouth is evident. • Wire insulation is flush with ends of splice. • Crimp is centered and properly formed to retain wires. • Heat shrinkable sleeve is centered and overlaps both insulation gaps (not shown).

Figure 8-25

8-8

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8 Splices

8.2.2 Splices – Crimped – Double Sided (cont.) Target - Class 1,2,3

• Correct color-coded heat shrinkable sleeve used (A). • Heat shrinkable sleeve is centered on the ferrule. • Meltable sealing rings have flowed.


• Ends of wires do not butt against wire stop. Wires are visible through inspection windows (arrows). • Wire insulation gap is less than two wire diameters including insulation. • Bellmouth is evident.


• Wire insulation gap is within two wire diameters including insulation on both ends (not shown). • Heat shrinkable sleeve ends are sealed to the wire insulation (no wire strands are exposed).

Figure 8-28

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January 2002

8-9

8 Splices

8.2.2 Splices – Crimped – Double Sided (cont.) Acceptable - Class 1,2,3

• Crimp indents are rotated (seamless splices only).

Figure 8-29 Acceptable - Class 1 Process indicator - Class 2,3

• Heat shrinkable sleeve is not centered yet sleeve ends are sealed to the wire insulation.


• Wire insulation extends into the wire crimp barrel (A). • Crimp indent is off the end of the splice (B). • Wire end(s) are not visible through the inspection window(s) (C). • Wire insulation gap is greater than two wire diameters including insulation (D). • Heat shrinkable sleeve does not overlap both insulation gaps (not shown).

Figure 8-31

8-10

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8 Splices

8.2.2 Splices – Crimped – Double Sided (cont.) Defect - Class 1,2,3

• Wire strands extend out of inspection window.


• Wire strands have pierced the heat shrinkable sleeve.

Figure 8-33

8.3 Splices – Ultrasonic Welded Refer to Section 7 for ultrasonic splice requirements.

IPC/WHMA-A-620

January 2002

8-11

8 Splices


8-12

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9 Connectorization

Connectorization The following topics are addressed in this section. 9.1 Hardware Mounting

9.1.1 Jackscrews 9.2 Strain Relief

9.2.1 Sleeving 9.3 Sleeving and Boots

9.3.1 Position 9.3.2 Bonding - Conductive Adhesive 9.4 Connector Damage

9.4.1 9.4.2 9.4.3 9.4.4

Criteria Limits - Hard Face - Mating Surface Limits - Soft Face - Mating Surface or Rear Seal Area Contacts

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January 2002

9-1

9 Connectorization

9.1 Hardware Mounting

9.1.1 Hardware Mounting – Jackscrews This section covers the height relationship of the face of the jackscrew to the associated connector face. This is critical to obtain maximum connector pin contact. Hardware stack-up for mounted connectors may be varied in order to locate the face of the jackscrew flush to 0.75 mm [0.030 in] below the face of the connector.


• Jackscrew face is flush to 0.75 mm [0.030 in] below the face of the connector. • Height is obtained by adding or removing washers (supplied with jackscrews).

Figure 9-1


• Jackscrew face extends above the connector face (Figure 9-2). • Face of Jackscrew is greater than 0.75 mm [0.030 in] below the connector face (Figure 9-3).

Figure 9-2

Figure 9-3

9-2

January 2002

IPC/WHMA-A-620

9 Connectorization

9.2 Strain Relief

9.2.1 Strain Relief – Sleeving Strain relief sleeving (e.g., insulating tape or sleeving or multi-conductor cable outer jacket) used to prevent wire movement when pushed or pulled length wise of the cable.


• Sleeving is visible between the clamp and the connector. • The split-lock washers are collapsed. Note: Clamps must be tightened to secure the bundle but need not be fully closed (touching).


• Sleeving is flush with the end of clamp (arrow). • Tape/sleeving is secured by the clamp to maintain sufficient strain relief.


• Sleeving inserted beyond connector causing stress on the wires (A). • The split lock washers are not collapsed (B). • Damage to sleeving that exposes the harness or other protected material (Not Shown).

Figure 9-6

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January 2002

9-3

9 Connectorization

9.3 Sleeving and Boots

9.3.1 Sleeving and Boots – Position Criteria applies to both adhesive and non-adhesive lined boots.


• Boot (A) is securely shrunk on the rear of connector adapter (crimp ring area). • Boot does not cover threaded adapter ring (B). • Boot overlap (C) of cable sleeving or jacket is at least three cable diameters in length to prevent exposed wires or braid when flexed. • Boot overlap does not interfere with operation of locking ring (D).

Figure 9-7


• Boot is shrunk over threaded adapter ring. • Boot does not interfere with locking ring ring.


• Boot interferes with locking ring. Defect - Class 2,3

• Boot overlap of cable sleeving or jacket is insufficient to prevent exposure of wires or braid when flexed.

Figure 9-9

9-4

January 2002

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9 Connectorization

9.3.2 Sleeving and Boots – Bonding – Conductive Adhesive Target - Class 1,2,3

• The boot is bonded to the connector on all sides with minimal adhesive buildup. The structural adhesive (typically black) fillet is visible. • The boot is parallel with the face of the connector in both axis. • There is no conductive adhesive (typically silver) outside the boot.

Figure 9-10


• The boot is parallel within 10° to the connector face in both axes. • The boot is bonded to the connector on all sides, and the structural adhesive is visible. Pin-holes are allowed.


• There is conductive adhesive outside the boot within the structural adhesive. • Boot and adhesive buildup does not exceed 3 mm [0.12 in] from connector surface (arrow).

Figure 9-12

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January 2002

9-5

9 Connectorization

9.3.2 Sleeving and Boots – Bonding – Conductive Adhesive (cont.) Acceptable - Class 1 Defect - Class 2,3

• Void or separation between the boot and connector. • Non-parallelism of boot and connector face exceeds 10° in either axis.

Figure 9-13


• Boot and adhesive buildup exceeds 3 mm [0.12 in] from the connector surface.

Figure 9-14


• Adhesive interferes with subsequent assembly steps.

Figure 9-15

9-6

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9 Connectorization

9.4 Connector Damage

9.4.1 Connector Damage – Criteria Target - Class 1,2,3

• Shell surface is clean, unmarked and undamaged. • Key or keyways are not distorted or damaged or mispositioned.

Figure 9-16


• Shell or positioning keys are damaged or contain deep scratches or burrs (A). • Damaged inner or outer ring (out-of-round condition) (B). • Key width or height has been reduced (C). • Key is mispositioned (Not Shown). • Connector shell or body is cracked, fractured or otherwise damaged.

Figure 9-17

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9-7

9 Connectorization

9.4.2 Connector Damage – Limits – Hard Face – Mating Surface Target - Class 1,2,3

• Connector face is intact with no evidence of chipping, cracks or other damage.

Figure 9-18 Acceptable - Class 1 Process Indicator - Class 2,3

• Connector face has been chipped but dielectric between seals is intact. • Chipping does not extend from one pin to the outer diameter of any adjacent pin.


• Chipping of the dielectric extends from pin to the outside diameter of any adjacent pin. • Crack extends from one pin to another.

Figure 9-20

9-8

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9 Connectorization

9.4.3 Connector Damage – Limits – Soft Face – Mating Surface or Rear Seal Area Target - Class 1,2,3

• Connector face is intact, with no evidence of cracks, chips, or damage.

Figure 9-21


• Material is missing with no damage to dielectric between cups (A). • Cut, fracture or tear that does not extend beyond cup diameter (B). • Cut, fracture or tear in dielectric face does not extend into the cup area (C).

Figure 9-22


• Cut, fracture or tear in dielectric extends beyond cup diameter. • Cut, fracture or tear that extends from cup through dielectric face or from one cup into another.

Figure 9-23

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January 2002

9-9

9 Connectorization

9.4.4 Connector Damage – Contacts Unless otherwise specified all unused contact locations will be filled with non-crimped contacts. When the contact must be crimped in order to install it in the connector housing, then the unused locations will be filled with crimped contacts. Contacts will be inspected for seating / locking position using a push force not to exceed 3.5 lbs. maximum. This Inspection is a check for loose contacts only. Care must be taken to use a probe that is compatible to the contact size and the push force must be parallel to the contact to prevent damage. Exceptions to the inspection include: • Prewired molded connectors. • Potted or molded connectors after molding/potting. Note: Inspection for contact seating is prior to potting or molding. • Solder Cup connectors. • Connector contact lead ends that are soldered into position (i.e., CCA’s). • Connector contact locking device that is visible through an inspection window. • Miniaturized connectors where contact size and configurations are vulnerable to push force damage.

9-10

January 2002

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9 Connectorization

9.4.4 Connector Damage – Contacts (cont.) Target - Class 1,2,3

• All connector contacts are to be installed in the connector to ensure they are fully seated and locked into position. • All locations in connector have been filled. Acceptable - Class 1,2,3

• When connector contacts have an assigned part number and contacts are not provided for all positions, it is not required to fill unused positions. • Connectors that are designed with coax contacts are exempt from the fill requirement for unused locations unless otherwise specified on the drawing.

Figure 9-24


• Socket is not fully seated and locked. Process Indicator - Class 2 Defect - Class 3

• Contact(s) missing when unused positions are required to be filled.

Figure 9-25

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January 2002

9-11

9 Connectorization

9.4.4 Connector Damage – Contacts (cont.) Defect - Class 1,2,3

• Pin is not seated and locked into position. • Damaged contact. • Contact is bent.

Figure 9-26

Figure 9-27

9-12

January 2002

IPC/WHMA-A-620

10 Molding/Potting

Molding/Potting The requirements in this chapter are imposed primarily to give confidence in the reliability of the wire or cable. Any allowable cosmetic anomalies should be agreed upon between the manufacturer and the user prior to the molding or potting operation. The following topics are addressed in this section. 10.1 Molding

10.1.1 10.1.2 10.1.3 10.1.4 10.1.5 10.1.6 10.1.7

Insulation Damage Filling Terminal Positioning Fit to Wire or Cable Flashing Chill Marks (Knit Lines), Stress Lines or Cracks Compound Color

10.2 Potting

10.2.1 10.2.2 10.2.3

Filling Fit to Wire or Cable Curing

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10 Molding/Potting

10.1 Molding

10.1.1 Molding – Insulation Damage Target - Class 1,2,3

• No insulation damage. Acceptable - Class 1,2,3

• The molding process has not damaged insulation beyond criteria listed in 3.4.

Figure 10-1


• Insulation is damaged beyond the insulation damage criteria listed in 3.4.

Figure 10-2

10-2

January 2002

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10 Molding/Potting

10.1.2 Molding – Filling Target - Class 1,2,3

• Mold filled completely with no recessions, bubbles, blowthrough or other cosmetic or functional abnormalities.


• Part has all features required by the drawing or specification. • All required marking is legible.

Figure 10-4

Acceptable - Class 1 Process Indicator - Class 2

• Blow through that is not on an electrical mating surface or does not prevent proper mating or function of the connector.

Figure 10-5

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10 Molding/Potting

10.1.2 Molding – Filling (cont.) Defect - Class 1,2,3

• Voids where molding material should be present. • Marking is incomplete or not legible.

Figure 10-6

Defect - Class 1,2

• Blow through present on an electrical mating surface or prevents proper mating or function of the connector. Defect - Class 3

• Blow through is present.

Figure 10-7

10-4

January 2002

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10 Molding/Potting

10.1.3 Molding – Terminal Positioning Target - Class 1,2,3

• Terminals fully inserted and aligned as required by drawing or specification. Acceptable - Class 1,2,3

• Any variation in contact height or alignment that does not compromise the electrical or physical function of the connector.

Figure 10-8


• Any variation in contact height or alignment that compromises the electrical or physical function of the connector.

Figure 10-9

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10 Molding/Potting

10.1.4 Molding – Fit to Wire or Cable Target - Class 1,2,3

• Molded material provides intimate contact with the wire or cable jacket for entire circumference of the wire or cable. Acceptable - Class 1

• No exposed conductors. • Molded material adheres to at least 75% of the circumference of the wire or cable jacket. Acceptable - Class 2,3

• No exposed conductors. • No exposed inner wires for multi-wire cables. • No gaps between molded material and wire or cable jacket when the assembly is in the as-molded configuration. Figure 10-10

10-6

• Molded material adheres to the entire circumference of the wire or cable jacket.

January 2002

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10 Molding/Potting

10.1.4 Molding – Fit to Wire or Cable (cont.) Defect - Class 1

• Any exposed conductors. • Molded material that does not adhere to at least 75% of the circumference of the wire or cable jacket. Defect - Class 2,3

• Any exposed conductors. • Any exposed inner wires for multi-wire cables. • Any gaps between molded material and wire or cable jacket when the assembly is in the as-molded configuration. • Molded material that does not adhere to the entire circumference of the wire or cable jacket.

Figure 10-11

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10 Molding/Potting

10.1.5 Molding – Flashing Target - Class 1,2,3

• No flashing.

Figure 10-12


• Flashing is not present on electrical mating surfaces. • No exposed sharp edges. • Flashing does not interfere with mating of the connector. Defect - Class 1,2 (not illustrated)

• Flashing on electrical mating surfaces. • Any sharp edges. • Any flashing that interferes with mating of the connector. Defect - Class 3 (not illustrated)

• Any Flashing.

Figure 10-13

10-8

January 2002

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10 Molding/Potting

10.1.6 Molding – Chill Marks (Knit Lines), Stress Lines or Cracks Target - Class 1,2,3

• No chill marks or stress lines (not illustrated). Process Indicator - Class 2 Defect - Class 3

• Any chill marks, stress lines or cracks.

Figure 10-14

10.1.7 Molding – Compound Color Not illustrated. Acceptable - Class 1,2,3

• Color is uniform and in accordance with drawing or specification. Defect - Class 2,3

• Color is not in accordance with drawing or specification. • Color is not consistent across the surface(s).

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10 Molding/Potting

10.2 Potting There are no illustrations for the potting section.

10.2.1 Potting – Filling Target - Class 1,2,3

• Potting material extends over insulation of all wires. • No potting material on the mating surfaces of the connector. • No bubbles or entrapped air. • No spillage. Acceptable - Class 1,2,3

• No bubbles or cavities that bridge between conductors. • No spillage present that interferes with the electrical or physical function of the connector. Defect - Class 1,2,3

• Potting material present on electrical mating surfaces of connector. • Any exposed conductors. • Any spillage that interferes with the electrical or physical function of the connector. Defect - Class 2,3

• Potting material that does not extend at least two wire diameters of the largest wire in the bundle above the end of the insulation of the wire(s). • Any bubbles or cavities that bridge between conductors.

10-10

January 2002

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10 Molding/Potting

10.2.2 Potting – Fit to Wire or Cable Target - Class 1,2,3

• Potting material provides intimate contact with the wire(s) or cable jacket for entire circumference of the wire(s) or cable. Acceptable - Class 1

• Potting material adheres to at least 75% of the circumference of the wire(s) or cable jacket. • No exposed conductors. Acceptable - Class 2,3

• No exposed inner wires for multi-wire cables. • No gaps between potting material and wire(s) or cable jacket when the assembly is in the as-potted configuration. • Potting material adheres to the entire circumference of the wire(s) or cable jacket. • No exposed conductors. Defect - Class 1

• Potting material that does not adhere to at least 75% of the circumference of the wire or cable jacket. • Any exposed conductors. Defect - Class 2,3

• Any exposed inner wires for multi-wire cables. • Any gaps between potting material and wire or cable jacket when the assembly is in the as-potted configuration. • Potting material that does not adhere to the entire circumference of the wire or cable jacket. • Any exposed conductors.

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10 Molding/Potting

10.2.3 Potting – Curing Target - Class 1,2,3

• Potting material is within manufacturer’s specified hardness range and tack free to the touch after following the manufacturer’s recommended cure schedule. Acceptable - Class 1,2

• Potting material has hardened and is tack free to the touch after following the manufacturer’s recommended cure schedule. Acceptable - Class 3

• Potting material is within the manufacturer’s specified hardness range after following the manufacturer’s recommended cure schedule. Defect - Class 1,2,3

• Potting material is tacky after following the manufacturer’s recommended cure schedule. Defect - Class 3

• Potting material is not within the manufacturer’s specified hardness range after following the manufacturer’s recommended cure schedule.

10-12

January 2002

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11 Cable Assemblies and Wires

Cable Assemblies and Wires The following topics are addressed in this section. 11.1 Cable Assemblies

11.1.1 11.1.1.1 11.1.1.2 11.1.2

Reference Surfaces Straight/Axial Connectors Right-Angle Connectors Length Measurement

11.2 Wires (As an Assembly)

11.2.1 11.2.2

Electrical Terminal Reference Location Length Measurement

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January 2002

11-1


11.1 Cable Assemblies

11.1.1 Cable Assemblies – Reference Surfaces 11.1.1.1 Cable Assemblies – Reference Surfaces – Straight/Axial Connectors Figure 11-1 identifies the points on a cable that are to be used as the reference surfaces.

C A D B

Figure 11-1

11.1.1.2 Cable Assemblies – Reference Surfaces – Right-Angle Connectors Figure 11-2 identifies the points on a cable that are to be used as the reference surfaces.

A

C

B

D

Figure 11-2

11-2

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11.1.2 Cable Assemblies – Length Measurement The length of a cable is measured from one end of the cable assembly to the other end. If reference surfaces are not specified on documentation, the reference surfaces shall be as specified in 11.1.1.1 and 11.1.1.2. Cable length measurement tolerance is provided in Table 11-1. Table 11-1 Cable Length Measurement Tolerance Cable Length Tolerance Metric

English

≤0.3 mm

+25 mm -0 mm

≤1 ft

+ 1 in -0 in

>0.3 mm - 1.5 m

+50 mm -0 mm

>1 ft - 5 ft

+ 2 in -0 in

>1.5 m - 3 m

+100 mm -0 mm

>5 ft - 10 ft

+ 4 in -0 in

>3 m - 7.5 m

+150 mm -0 mm

>10 ft - 25 ft

+6 in -0 in

>7.5 m

+5% -0%

>25 ft

+5% -0%


• Cable length meets specified nominal drawing length.

Figure 11-3


• Cable length is equal to or less than maximum acceptable. min max

• Cable length is equal to or greater than minimum acceptable.

Figure 11-4


A D

B C

• The cable length is less than minimum (A, D). • The cable length exceeds maximum (B, C).

min max

Figure 11-5

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11.2 Wires (As an Assembly) Wires as a finished assembly or product generally consists of an insulated wire with one or both ends of the wire installed into electrical terminal(s).

11.2.1 Wires – Electrical Terminal Reference Location If reference locations are not specified on documentation, use the reference surfaces specified in 11.2.1 and 11.2.2. Figure 11-6 illustrates the dimensional reference location (RL) or surface (RS) for several types of insulated and uninsulated electrical terminals. For ring (A), hook (B) and fork (C) terminals the fastener hole center shall be used as the reference location (RL). For quick-disconnect (D) and bullet (E) terminals the end of the terminal shall be used as the reference surface (RS). Figures 11-7, 11-8 and 11-9 illustrate the dimensional reference location for wires and cables.

RL

A

B

C RS

D

D

E

Figure 11-6

11-4

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11.2.2 Wires – Length Measurement The overall wire length, as an assembly, of a wire includes all or a portion of the electrical terminal(s) from their reference location or reference surface.


• The wire lengths from one wire end reference location or reference surface to the other are equal to the ‘‘nominal’’ wire length (nom).

nom Figure 11-7 Acceptable - Class 1,2,3

• Wire length is equal to or less than maximum acceptable. • Wire length is equal to or greater than minimum acceptable.

min max Figure 11-8


• The wire length exceeds maximum acceptable (A).

A

• The wire length is less than minimum acceptable (B).

B min max Figure 11-9

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11-6

January 2002

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12 Marking/Labeling

Marking/Labeling Note: For the purposes of this section, marking and labeling are referred to as marking. Marking is not required unless specified on the controlling document. If a marking method has not been specified by the controlling document, any marking method that meets the requirements of this section is acceptable. Regardless of the marking method used, markings must contain the required information, be legible, be permanent in the intended application, and must not damage the product nor impair its function. Note: Additional (non-required) information may be marked onto the product for internal purposes. This marking is not subject to the provisions of this section, provided that: • The marking does not conflict with, and is separated from, required information; and,

The following topics are addressed in this section. 12.1 Content 12.2 Legibility 12.3 Permanency 12.4 Location 12.5 Functionality 12.6 Marker Sleeve

12.6.1 12.6.2

Wrap Around Tubular

• Prior to delivery non-permanent internal markings should be removed for Class 2 and shall be removed for Class 3 products. Criteria with obvious understanding may not have illustrations.

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12 Marking/Labeling

12.1 Content Acceptable - Class 1,2,3

• Markings include the content specified by the controlling document. Defect - Class 1,2,3

• Marking content incorrect. • Marking missing.

12.2 Legibility Target - Class 1,2,3

• Markings legible when viewed without magnification. Markings are distinct, of uniform height, and of a color that contrasts with the background. • Machine-readable markings (bar codes) must be of the proper specified industry standard format. • Bar codes can be read successfully with one attempt using either a wand or laser type scanner.

Figure 12-1

12-2

January 2002

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12 Marking/Labeling

12.2 Legibility (cont.) Acceptable - Class 1,2,3

• Marking legible but blurred. • Bar codes can be successfully read with three or fewer attempts using a wand type scanner. • Bar codes can be successfully read with two or fewer attempts using a laser scanner.

Figure 12-2


• Marking not legible. • Bar codes cannot be successfully read with three or fewer attempts using a wand type scanner. • Bar codes cannot be successfully read with two or fewer attempts using a laser scanner.

Figure 12-3

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12 Marking/Labeling

12.3 Permanency Note: Marking should be resistant to its handling, assembly and service environment. The service environment should be defined in the procurement documents. Handling is the normal exposure to assembly, storage and transport environments. Acceptable - Class 1,2,3

• Markings remain legible after exposure to handling, assembly and required environmental testing. Defect - Class 1,2,3

• Markings not legible or present after exposure to handling, assembly and required environmental testing.

12.4 Location Acceptable - Class 1,2,3

• Marking present in location(s) designated by controlling document. Acceptance - Class 1 Defect - Class 2,3

• Marking not in specified location(s). • If the location is not specified on an individual conductor or breakout, the marking is more than 150 mm [6 in] from the end of the conductor or breakout.

12-4

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12 Marking/Labeling

12.5 Functionality Target - Class 1,2,3

• The marking does not impair the function of the product in its intended application. • The marking process has not damaged the product.


• Insulation deformation does not exceed 50% of the insulation thickness for 20 AWG and smaller wire diameters. • Insulation deformation does not exceed 25% of the insulation thickness for 18 AWG and larger wire diameters. • Insulation exhibits slight discoloration as a result of marking. • Insulation deformation does not reduce insulating properties to less the minimum dielectric requirements.

Figure 12-5


• Insulation deformed more than 50% of the insulation thickness for 20 AWG and smaller wire diameters. • Insulation deformed more than 25% of the insulation thickness for 18 AWG and larger wire diameters. • Insulation scorched, charred, melted or brittle as a result of the marking process. • Marking present on exposed (uninsulated) conductor in region where conductor will connect to mating surface or hardware. Figure 12-6

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12 Marking/Labeling

12.6 Marker Sleeve

12.6.1 Marker Sleeve – Wrap Around Target - Class 1,2,3

• The marker sleeve wraps around the cable 1.5 times and is secure. • The overlap of the marker sleeve is aligned at the edges. • The marker sleeve is smooth.

Figure 12-7


• The marker sleeve wraps around the cable a minimum of 1.25 times to a maximum of 2 times and is secure. • The marker sleeve is slightly wrinkled and skewed. • The identification legibility is maintained.

Figure 12-8


• The marker sleeve is severely wrinkled, or skewed.

Figure 12-9

12-6

January 2002

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12 Marking/Labeling

12.6.1 Marker Sleeve – Wrap Around (cont.) Defect - Class 1,2,3

• The marker sleeve overlap is not secure.

Figure 12-10


• The marker sleeve does not overlap.

Figure 12-11

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January 2002

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12 Marking/Labeling

12.6.2 Marker Sleeve – Tubular Target - Class 1,2,3

• The identification marking reads towards the connector. • The marker sleeve is completely shrunk and secure. • The marker sleeve is positioned next to the boot (or connector when no boot exists).

Figure 12-12


• The identification marking reads away from the connector. • The marker sleeve is shrunk sufficient to remain secure (no sliding). • The marker sleeve is positioned on the boot. • Marker sleeve may be positioned over ferrules and splices (not shown).

Figure 12-13


• Any splits or holes.

Figure 12-14

12-8

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13 Coaxial and Twinaxial Cable Assemblies

Coaxial and Twinaxial Cable Assemblies For coaxial and twinaxial assemblies to function properly, it is critical to follow all assembly instructions provided by the manufacturer. In general, the pieces of the connectors must remain as concentric as possible. The relationship of the outside diameter (OD) of the cable center conductor/connector contact, the thickness of the dielectric, and the inside diameter (ID) of the connector body and cable shielding are critical to electrical and mechanical function of the assembly. Insulation integrity is important to preclude shorting of shields to each other or shorting of shields to the center conductor. The following topics are addressed in this section: 13.1 Stripping

13.6 Terminal Cover - Soldering 13.7 Shield Termination

13.7.1 13.7.2

Clamped Ground Rings Crimped Ferrule

13.8 Center Pin Position 13.9 Semirigid Coax

13.9.1 13.9.2 13.9.3 13.9.4 13.9.5

Bending and Deformation Surface Condition Dielectric Cutoff Dielectric Cleanliness Solder

13.2 Center Conductor Termination

13.2.1 13.2.2

13.10 Swage-Type Connector

Crimp Solder

13.3 Solder Ferrule Pins

13.11 Soldering and Stripping of Biaxial or Twinaxial Wire - Low Temperature Insulation

13.3.1 13.3.2

13.11.1 Jacket and Tip Installation 13.11.2 Ring Installation

General Insulation

13.4 Coaxial Connector - Printed Wire Board Mount 13.5 Coaxial Connector - Center Conductor Length Right Angle Connector

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January 2002

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13.1 Stripping Coaxial cable is manufactured with several primary amounts of braid/shield coverage. The majority of cable fits into just a few groups. Some cable is identified as double ‘‘shield’’ but the shield is a foil wrap rather than a second braid. The foil is not used during mechanical attachment so this type of cable would still be identified as a single braid. The largest group of coaxial cable types has approximately 90% braid coverage and can tolerate a greater quantity of missing or damaged braid that may result from the stripping operation. Another group of coaxial cable types, typified by RG-6/U, has approximately 61% braid coverage. With this amount of coverage, effectively 40% is already ‘‘missing’’ and additional damage requirements are much tighter. Double braid coverage is the most tolerant of missing strands while still maintaining the required functionality. Table 13-1 provides the damaged or missing braid allowances. Table 13-1 Damaged or Missing Braid Allowances Specified Braid Coverage

Maximum Amount of Missing or Damaged Braid

<63%

10%

≥63%

25% Outer Braid 50%

Double Braid

Cumulative 25%


• Smooth, clean cut; no jagged edges. • No burn marks or damage on insulation or dielectric. • Braid/shield cut even; no long strands. • Braid lies smooth and flat after cut with no damaged or loose pieces.

Figure 13-1

13-2

January 2002

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13.1 Stripping (cont.) Acceptable - Class 1,2,3

• Slight marks on dielectric. • Minor unraveling of braid. • Slight discoloration on dielectric from thermal stripping. Acceptable - Class 1 Process Indicator - Class 2,3 Figure 13-2

• Missing or damaged braid (circumference) does not exceed requirements of Table 13-1.


• Braid twisted/birdcaged. • Scored braid (circumference) exceeds the allowance of Table 13-1. • Outer jacket/insulation frayed, damaged. • Missing or damaged braid (circumference) exceeds the allowance of Table 13-1. • Uneven cut on braid; any long strands. • Discernible nicks or cuts in center conductor. • Burns or melted areas on dielectric. • Damage to center dielectric reducing insulation diameter by more than 10%.

Figure 13-3 1. 2. 3. 4. 5. 6.

Braid twisted Braid scored Outer jacket frayed Unwoven braid, missing strands Ragged dielectric, tool marks Incomplete removal of strands

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13-3


13.2 Center Conductor Termination

13.2.1 Center Conductor Termination – Crimp Target - Class 1,2,3

• Crimp is centered on crimp area of terminal. • No damage to terminal or dielectric. • Equal compression on all crimp surfaces. Acceptable - Class 1,2,3

• Crimp not centered on crimp area of terminal but does not cause damage to terminal. Figure 13-4

13-4

• Dielectric does not enter barrel of terminal.

January 2002

IPC/WHMA-A-620


13.2.1 Center Conductor Termination – Crimp (cont.) Defect - Class 1,2,3

• Crimp is not centered in crimp area of terminal and causes damage to terminal (Figure 13-5). • Conductor strand(s) not captured in terminal (Figure 13-6). • Terminal damaged by crimp (Figures 13-5, 7 and 8). • Pin shows ‘‘dog ear’’ of excess material (Figure 13-7). • Crimp loose - does not hold terminal (not shown). Figure 13-5

• Braid strand(s) caught in terminal (not shown).

Figure 13-6

Figure 13-7

Figure 13-8

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January 2002

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13.2.2 Center Conductor Termination – Solder Target - Class 1,2,3

• During assembly center conductor visible across full diameter of inspection window. • The inspection window is filled with solder. • No solder on outside of terminal. • Solder in inspection window does not protrude beyond terminal barrel. Figure 13-9

• Solder is wetted to both the terminal and the conductor. • No melt/damage to dielectric or terminal. • No residue when connection is required to be clean. • Terminal is flush against dielectric.


• Solder slightly protrudes from inspection window, but will not interfere with assembly. • Minor flare of dielectric due to heat from solder does not interfere with assembly of connector. • Gap between dielectric and terminal meets manufacturer’s requirements. In the absence of manufacturer’s specs, there is no gap. Figure 13-10

13-6

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13.2.2 Center Conductor Termination – Solder (cont.) Defect - Class 1,2,3

• Braid extends into barrel of terminal (not shown). • Strand(s) of center conductor not captured in terminal (not shown). • Solder not visible in inspection window (Figure 13-11). • No discernible solder fillet or wetting between terminal and conductor (Figure 13-11). • Center conductor not visible in inspection window (not shown).

Figure 13-11

• Excess solder prevents proper assembly of connector and electrical impedance of the connector (Figure 13-12). • Damage to dielectric due to heat from solder (Figure 13-12). • Residue remains when connection is required to be clean. • Terminal embedded into dielectric. • Gap between terminal and dielectric exceeds manufacturer’s requirements.

Figure 13-12

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January 2002

13-7


13.3 Solder Ferrule Pins

13.3.1 Solder Ferrule Pins – General Target - Class 1,2,3

• Solder fillet is evident in inspection holes. • Shield weave pattern is intact.

Figure 13-13


• Wire twist form is disturbed. • Solder fillet is evident in inspection holes.

Figure 13-14

13-8

January 2002

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13.3.1 Solder Ferrule Pins – General (cont.) Defect - Class 1,2,3

• Shield strand is protruding through sleeving or out of inspection hole. • Solder ring is improperly flowed. • Solder buildup on outside surface of contact.

Figure 13-15

Figure 13-16

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January 2002

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13.3.2 Solder Ferrule Pins – Insulation Target - Class 1,2,3

• Pin tip insulation shows no evidence of melting. • Insulation in inspection hole is flush with outside pin surface.

Figure 13-17


• Pin tip insulation has melted flush to the surface of contact, and contact hole is free of insulation obstruction. • Insulation in inspection hole is protruding beyond the pin surface. Does not prevent contact mating.


• Insulation has melted beyond the outside surface of contact, and contact hole is obstructed (not shown). • Insulation in inspection hole is protruding beyond the pin surface. Prevents contact mating.

Figure 13-19

13-10

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13.4 Coaxial Connector – Printed Wire Board Mount Target - Class 1,2,3

• Wire is positioned and centered between the four connector leads. • Shield weave pattern is intact. • Solder fillet is evident between shield and connector. • Sleeve completely covers shield.

Figure 13-20


• Wire is positioned 0.75 mm [0.03 in] or less from center of the four connector leads. • Solder fillet is evident between shield and connector. • Shield weave pattern is slightly disturbed.

Figure 13-21

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January 2002

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13.4 Coaxial Connector – Printed Wire Board Mount (cont.) Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Shield extends beyond sleeving (A). • Shield is piercing sleeving (B). Defect - Class 1,2,3

• Solder fillet is not evident between shield and connector. • Wire is positioned greater than 0.75 mm [0.03 in] from the center (C) of the four connector leads.

Figure 13-22

13.5 Coaxial Connector – Center Conductor Length – Right Angle Connector Target - Class 1,2,3

• Center conductor is flush with edge of the slotted terminal. • End of dielectric is flush with inside of connector cavity (not shown).

Figure 13-23

13-12

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13.5 Coaxial Connector – Center Conductor Length – Right Angle Connector (cont.) Acceptable - Class 1,2,3

• Center conductor extends beyond the edge of the slotted terminal no greater than one center conductor diameter. • Center conductor does not contact connector housing. • Dielectric extends into connector cavity. Air gap is maintained between slotted terminal and dielectric.


• Center conductor is not flush, or visible beyond the edge of the slotted terminal.


• Center conductor extends beyond the edge of the slotted terminal greater than one center conductor diameter. • Center conductor contacts connector housing. Acceptable - Class 1 Process Indicator - Class 2,3

• Dielectric extends into connector cavity and touches the slotted terminal.

Figure 13-26

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13.6 Terminal Cover – Soldering Target - Class 1,2,3

• Continuous solder fillet between connector body and cover.

Figure 13-27

Acceptable - Class 1

• Solder fillet, although non-continuous, exists greater than 330° around connector body and cover. Acceptable - Class 2,3

• Fillet is continuous between connector body and cover.

Figure 13-28

13-14

January 2002

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13.6 Terminal Cover – Soldering (cont.) Acceptable - Class 1,2,3

• Solder buildup over entire cover, but does not interfere with subsequent assembly steps.

Figure 13-29

Defect - Class 1

• Solder fillet is non-continuous or less than 330° around connector body and cover. Defect - Class 2,3

• Solder fillet is non-continuous or less than 360° around connector body and cover.

Figure 13-30

IPC/WHMA-A-620

January 2002

13-15


13.7 Shield Termination

13.7.1 Shield Termination – Clamped Ground Rings Target - Class 1,2,3

• Braid/shield evenly distributed around the ground ring. • Shield wires are close to, but not in contact with, the outer shoulder flange of the shield ground ring. • Shield ground wires hold the shield ground ring in tight contact with the cable outer jacket.

Figure 13-31 1. Braid 2. Ground Ring


• Shield wires not uniformly distributed around the ground ring. • Shield wires contact outer shoulder flange of the shield ground ring but do not impede assembly of the connector.

Figure 13-32


• Shield wires do not hold the shield ground ring in tight contact with the cable outer jacket. • The connector turns on the cable.

13-16

January 2002

IPC/WHMA-A-620


13.7.2 Shield Termination – Crimped Ferrule Target - Class 1,2,3

• Crimp on ferrule located tight against connector body. • Ferrule butted up tight to connector body. • Connector and/or ferrule do not turn or move on cable after crimping.

Figure 13-33


• Ferrule not butted up tight to connector body but gap is less than 25% of ferrule length. Acceptable - Class 2,3

• Gap between connector body and ferrule is less than 0.75 mm [0.030 in]. • Distance between connector body and start of crimp is less than 0.75 mm [0.030 in].

Figure 13-34

IPC/WHMA-A-620

January 2002

13-17


13.7.2 Shield Termination – Crimped Ferrule (cont.) Defect - Class 1,2,3

• Crimp extends over the cable. • Double crimps on ferrule (Figure 13-36). • Ferrule and/or connector turns/moves on cable after crimping. • Gap between ferrule and connector body is more than the maximum allowed. • Distance between connector body and crimp is more than the maximum allowed. • Ferrule shows ‘‘dog ear’’ of excess material (Figure 13-37 shows cross section example of ‘‘dog ear’’).

Figure 13-35

Figure 13-36

Figure 13-37 1. Acceptable 2. Dog ear

13-18

January 2002

IPC/WHMA-A-620


13.8 Center Pin Position The location of the center conductor’s connector contact is critical to meeting the electrical signal’s integrity requirements. In the case of ‘‘fixed’’ coaxial cable center conductor contacts, the position of the center contact is determined by the design of the connector, and the assembly process generally minimally affects the position of the center conductor’s contact. The position of ‘‘floating’’ center conductor contacts is greatly affected by the assembly, primarily due to shield termination and wire preparation cut/trim lengths.


• Center pin fully seated into housing of connector. • Pin height is correct.


• Center pin not fully seated into housing of connector. • Center pin is bent.

Figure 13-39

IPC/WHMA-A-620

January 2002

13-19


13.9 Semirigid Coax The acceptability of semirigid cable assemblies is greatly affected by three factors. • Application - Bend radii and deformation of a cable assembly have a greater or lesser effect depending upon the frequency the cable will carry. • Cleanliness - Mating surfaces, including test equipment must be free of all foreign material (i.e., flux residue, metallic or other particles). • Tooling - Proper tooling will prevent cable deformation and surface damage. The criterion that follows will establish acceptance conditions for the most common applications. Visual inspection of the cable cannot, in all cases determine its fitness for use. With the exception of obvious damage or improper solder connections, the correct function of the cable assembly will be the determining factor of acceptance.

13.9.1 Semirigid Coax – Bending and Deformation Target - Class 1,2,3

• Bend is uniform and has an inside radius greater than 3.5 times the cable diameter. • Diameter of cable is constant and does not deform in the bend area. • No evidence of wrinkles.

Figure 13-40

13-20

January 2002

IPC/WHMA-A-620


13.9.1 Semirigid Coax – Bending and Deformation (cont.) Acceptable - Class 1,2,3

• Inside bend radius is equal to or greater than the limits shown in Table 13-2. • No obvious wrinkles. Table 13-2 Nominal Cable Diameter

Inside Bend Radius

0.141 in

2.5 mm [0.100 in] min

0.086 in

1.25 mm [0.050 in] min

0.047 in

1.25 mm [0.050 in] min

Note: Nominal cable diameters are industry-defined using only the Imperial measurements shown.

Figure 13-41


• Deformation (eccentricity) of the cable is within the limits of Table 13-3. Table 13-3 Cable Eccentricity Limits in any Dimension

Nominal Cable Diameter

Maximum

Minimum

0.141 in

0.151 in

0.131 in

0.086 in

0.092 in

0.080 in

0.047 in

0.051 in

0.043 in


Figure 13-42

IPC/WHMA-A-620

January 2002

13-21


13.9.1 Semirigid Coax – Bending and Deformation (cont.) Defect - Class 1,2,3

• Cable bend is distorted and not uniform. • Minimum bend radius is less than the limits of Table 13-2. • Deformation (out-of-round) is beyond the limits of Table 13-3. • Cable jacket has obvious wrinkles.

Figure 13-43

13-22

January 2002

IPC/WHMA-A-620


13.9.2 Semirigid Coax – Surface Condition Target - Class 1,2,3

• Outside surface of the cable is smooth. • No tool marks, scratches or abrasions.

Figure 13-44


• Outside surface of the cable has minor tooling marks, scratches or abrasions. • Base metal (copper) is not exposed.

Figure 13-45


• Cable has deep tool marks, scratches or abrasions. Defect - Class 1,2,3

• Base metal (copper) is exposed.

Figure 13-46

IPC/WHMA-A-620

January 2002

13-23


13.9.3 Semirigid Coax – Dielectric Cutoff Acceptable - Class 1,2,3

• Dielectric is flush with connector face. • No air gap between dielectric and cable shield.

Figure 13-47


• Dielectric is flush with connector face. • Center conductor is perpendicular to dielectric/connector face.

Figure 13-48


• Dielectric is below flush with connector face.

Figure 13-49

13-24

January 2002

IPC/WHMA-A-620


13.9.3 Semirigid Coax – Dielectric Cutoff (cont.) Acceptable - Class 1,2,3

• Shield roll over is minimal. Distance from the edge of the center conductor (A) to the shield is equal to, or greater than the values in Table 13-4. Table 13-4 Nominal Cable Diameter

Minimum Distance - Edge of Center Conductor to Shield

0.141 in

0.75 mm [0.03 in]

0.086 in

0.50 mm [0.02 in]

0.047 in

0.25 mm [0.01 in]


Figure 13-50


• Air gap between dielectric and cable shield.

Figure 13-51

Figure 13-52

IPC/WHMA-A-620

January 2002

13-25


13.9.3 Semirigid Coax – Dielectric Cutoff (cont.) Defect - Class 1,2,3

• Dielectric protrudes above connector face. • Center conductor is bent.

Figure 13-53


• Shield roll over reduces the distance from the edge of the center conductor to the shield less than the limits of Table 13-4.

Figure 13-54

13-26

January 2002

IPC/WHMA-A-620


13.9.4 Semirigid Coax – Dielectric Cleanliness Acceptable - Class 1,2,3

• Dielectric material has no foreign particles (metallic or nonmetallic) embedded in or on its surface.

Figure 13-55


• Dielectric material is contaminated with foreign particles.

Figure 13-56

IPC/WHMA-A-620

January 2002

13-27


13.9.5 Semirigid Coax – Solder Target - Class 1,2,3

• Solder fillet 100% around the connector body and cable. • No solder outside joint region. • No residue when connection is required to be clean. • No voids or separation between connector body and cable. • No solder on connector body. • Shield inserted in connector body.


• Solder film/build-up on connector body but will not interfere with subsequent assembly steps.

Figure 13-58 Acceptable - Class 1 Defect - Class 2,3

• Insufficient solder. • Solder fillet greater than 270° but less than 360°. • Solder fillet has voids or is dewetted (not shown).

Figure 13-59

13-28

January 2002

IPC/WHMA-A-620


13.9.5 Semirigid Coax – Solder (cont.) Defect - Class 1

• Solder fillet is less than 270°. Defect - Class 2,3

• Solder fillet is less than 360°. Defect - Class 1,2,3

• Voids or areas of missing solder. • Excess solder onto cable or connector impedes subsequent assembly operations. • Residue when connection is required to be clean. • Evidence of dewetting. • Solder buildup on connector body that interferes with subsequent assembly steps. Figure 13-60

• Solder is nonwetted or dewetted. • Shield strand is not contained in connector barrel (not shown).

Figure 13-61

Figure 13-62

IPC/WHMA-A-620

January 2002

13-29


13.10 Swage-Type Connector Acceptable - Class 1,2,3

• Swage ferrule is compressed into the connector body. • Gap between ferrule shoulder and nut face does not exceed 0.5 mm [0.02 in].

Figure 13-63


• Gap between ferrule shoulder and nut face exceeds 0.5 mm [0.02 in]. • Swage ferrule is not compressed into connector body.

Figure 13-64

13-30

January 2002

IPC/WHMA-A-620


13.11 Soldering and Stripping of Biaxial or Twinaxial Wire – Low Temperature Insulation 13.11.1 Soldering and Stripping of Biaxial or Twinaxial Wire – Low Temperature Insulation – Jacket and Tip Installation Figure 13-65 shows the parts of this connector. All adjacent parts need to contact each other to insure the stability of connector. This criteria applies to both male and female connectors.

2

1

3

4

5

6 8

7

Figure 13-65 1. Tip 2. Cone

3. Shield 4. Nut

5. Jacket 6. Dielectric

7. Conductors 8. Ring


• Cone is under shield and jacket. Shield is flush with edge of cone (A). • Tip conductor insulation is extended more than 50% of window length in (notched insert), and there is no exposed wire showing (B). • Solder on the solder section of tip is flush to slightly concave (C). Note: Complete connector assembly not shown.

Figure 13-66

IPC/WHMA-A-620

January 2002

13-31


13.11.1 Soldering and Stripping of Biaxial or Twinaxial Wire – Low Temperature Insulation – Jacket and Tip Installation (cont.) Acceptable - Class 1 Process Indicator - Class 2,3

• Shield and jacket extends over more than 50% of cone (A). • Tip conductor exposed wire is less than 50% of window length (notched insert) (B). • A thin film of solder is on the outside solder section of tip surface. (Solder film is not allowed on contact mating surface.)

Figure 13-67


• Jacket extends less than 50% over cone as required securing nut (A). • Insulation on both conductors is less than 50% of notch insert window (B). • Solder buildup on solder section of tip (C). • Solder film on the mating end of tip (D). (Solder film is not allowed on mating surface of tip.)

Figure 13-68

13-32

January 2002

IPC/WHMA-A-620


13.11.2 Soldering and Stripping of Biaxial or Twinaxial Wire – Low Temperature Insulation – Ring Installation Target - Class 1,2,3

• Wire, Insulation, or solder does not extend above ring profile.

Figure 13-69


• The ring (A) has a thin film of solder on the outside surface. • Solder film is not on mating surface (B).

Figure 13-70


• Wire, insulation, or solder extends above ring profile. • Solder on mating surface.

Figure 13-71

IPC/WHMA-A-620

January 2002

13-33



13-34

January 2002

IPC/WHMA-A-620

14 Wire Bundle Securing

Wire Bundle Securing The following topics are addressed in this section: 14.1 Tie Wrap/Lacing Application

14.1.1 14.1.2 14.1.3

Tightness Damage Spacing

14.2 Breakouts

14.2.1 14.2.2

Individual Wires Spacing

14.3 Wire Bundles

14.3.1 14.3.2 14.3.3 14.3.4

Wire Crossover Coaxial Cable Routing Unused Wire Termination Ties over Splices and Ferrules

IPC/WHMA-A-620

January 2002

14-1


14.1 Tie Wrap/Lacing Application Figures 14-1, 14-2 and 14-3 are provided as guidance for applying lacing. The ends start and finish with clove-hitches that are secured with square knots. Figure 14-1 also shows running lock stitches. Figure 14-3 is an example of a surgeons knot. Note: Do not subject wax impregnated lacing tape to cleaning solvents.

Figure 14-2

Figure 14-1

14-2

Figure 14-3

January 2002

IPC/WHMA-A-620


14.1 Tie Wrap/Lacing Application (cont.) Target - Class 1,2,3

• The first and last stitch of continuous lacing is tied with a clove hitch and secured with a square knot, surgeons knot, or other approved knot (1). • Continuous lacing is done with lock stitches (2). • Continuous lacing utilizes a double lock stitch before and after each breakout of four or more wires (3). • Continuous branch lacing is started on the trunk. • Lacing is trimmed 10 mm [0.40 in] after the knot (4). • Restraining devices are locking. (They should remain secure for the expected service life of the product.) • Cut end of tie wrap is square and flush to the face of the tie wrap. Figure 14-4


• The end of the tie wrap is cut off not greater than one tie wrap thickness and is reasonably square to the face of the tie wrap. Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Cut end protrusion (1) greater than tie wrap thickness.

Figure 14-5

IPC/WHMA-A-620

January 2002

14-3


14.1 Tie Wrap/Lacing Application (cont.) Acceptable - Class 1,2,3

• Cable lacing begins and ends with a locking knot. • Lacing is tight and wires are kept secure in a neat bundle.

Figure 14-6 Acceptable - Class 2,3

• Continuous lacing may utilize a single lock stitch on a branch after a double lock stitch.

Figure 14-7 Defect - Class 1

• Square knot, surgeons knot, or other approved knot not used where required (1). Defect - Class 2,3

• Lock stitches not used. • Double lock stitch not used where required. • Branch lacing not started on trunk. • Excess lacing trimmed either too close to knot (less than 6 mm [0.25 in]) (2), or too far from knot (greater than 25 mm [1.0 in]) (3).

Figure 14-8

14-4

January 2002

IPC/WHMA-A-620


14.1 Tie Wrap/Lacing Application (cont.) Defect - Class 1,2,3

• Lacing or spot tie is loose, leaving wires loose in the wire bundle (1). • Lacing or spot tie is too tight, cutting into insulation (2). • Continuous lacing does not use lock knots. • Wires not constrained securely and uniformly or are birdcaged. • Cable tied with a bowknot or other non-locking knot. This tie may eventually loosen.

Figure 14-9

Figure 14-10

IPC/WHMA-A-620

January 2002

14-5


14.1.1 Tie Wrap/Lacing Application – Tightness Target - Class 1,2,3

• Restraining devices do not move. • Restraining devices do not cause noticeable indentation or distortion of the wires of the assembly.

Figure 14-11


• Bundle is distorted by the restraining devices. • Insulation is compressed or damaged by the restraining device. • Continuous lacing does not employ lock stitches. • Tie wraps are inverted or not locked. • Restraining devices move.

Figure 14-12

14-6

January 2002

IPC/WHMA-A-620


14.1.2 Tie Wrap/Lacing Application – Damage Target - Class 1,2,3

• Restraining devices are not worn, frayed, nicked, or broken in any location. • Restraining devices do not have sharp edges that may be a hazard to personnel or equipment.

Figure 14-13

Acceptable - Class 1,2 Defect - Class 3

• Restraining devices exhibit minor fraying, nicks, or wear of less than 25% of the device thickness. Defect - Class 1,2,3

• Damage or wear to restraining device (1). • Sharp edges that are a hazard to personnel or equipment (2). • Broken lacing ends are not tied off using a square knot, surgeons knot, or other approved knot (3).

Figure 14-14

IPC/WHMA-A-620

January 2002

14-7


14.1.3 Tie Wrap/Lacing Application – Spacing Target - Class 1,2,3

• Spacing (S) of restraining devices from the rearmost connector accessory or between each other is three diameters of the wire bundle or 10 cm [4 in] whichever is less. • Spacing of restraining devices is uniform. Acceptable - Class 1 Process Indicator - Class 2,3

• Restraining devices are irregularly spaced. Acceptable - Class 2,3 Figure 14-15

• Spacing of restraining devices is not greater than four wire bundle diameters or 13 cm [5 in], whichever is less. Defect - Class 1

• Spacing of restraining devices is so large that the shape of the wire bundle is not maintained. Defect - Class 1,2,3

• Wire bundles show evidence of birdcaging. Defect - Class 2,3

• Spacing of restraining devices is greater than four wire bundle diameters or 10 cm [4 in], whichever is less.

14-8

January 2002

IPC/WHMA-A-620


14.2 Breakouts

14.2.1 Breakouts – Individual Wires Acceptable - Class 1,2,3

• A restraining device is used prior to each breakout. • If continuous lacing is used, the first wire breakout in a series is double lock stitched (not shown). • A double lock stitch is used before and after any breakout of four or more wires.

Figure 14-16

IPC/WHMA-A-620

January 2002

14-9


14.2.1 Breakouts – Individual Wires (cont.) Defect - Class 2,3

• Spot tie or tie wrap not used prior to wire breakout (1). • Spot tie or tie wrap not used prior to breakout of up to three wires in close proximity. • Double lock stitch not used before and after breakout of four or more wires when continuous lacing is used.

Figure 14-17

14.2.2 Breakouts – Spacing Target - Class 1,2,3

• Restraining device is used immediately before and after each branch. • The closest restraint on any branch of a breakout is two diameters (D) of that bundle or 1.25 cm [0.5 in] whichever is greater.

Figure 14-18

14-10

January 2002

IPC/WHMA-A-620


14.2.2 Breakouts – Spacing (cont.) Acceptable - Class 1,2,3

• Restraining devices are placed before and after all breakouts. • Spacing of first restraint from the breakout is three diameters of the wire bundle or 10 cm [4 in] whichever is less. Note: Figures 14-19 through 14-25 provide examples of typically acceptable restraining configurations. Figure 14-19

Figure 14-20

Figure 14-21

Figure 14-22

Figure 14-23 1. Single lock stitch 2. Double lock stitch

Figure 14-24

IPC/WHMA-A-620

Figure 14-25

January 2002

14-11


14.2.2 Breakouts – Spacing (cont.) Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Spacing of first restraint from the breakout is more than three diameters of the wire bundle or 10 cm [4 in] whichever is less.

Figure 14-26


• Restraining device not used at each branch (1). • Restraining device located too far from junction (2). • Restraining device imparts stress on any wires in the bundle by deforming the radius (3).

Figure 14-27

14-12

January 2002

IPC/WHMA-A-620


14.3 Wire Bundles

14.3.1 Wire Bundles – Wire Crossover Target - Class 1,2,3

• Wire lay is essentially parallel to the axis of the bundle with no crossover. • Spot ties or tie straps around the bundle are tight but not to the point of cutting or permanently damaging wire insulation. • Spot ties or tie straps are spaced evenly and at an increment that will maintain the bundles rigidity and desired form.

Figure 14-28


• Wires twist and crossover, but bundle is essentially uniform. • Wires are not kinked sharply nor is wire insulation damaged at cross over or tie points.

Figure 14-29

Defect - Class 2,3

• Bundle has lost uniformity.

Figure 14-30

IPC/WHMA-A-620

January 2002

14-13


14.3.2 Wire Bundles – Coaxial Cable Routing Acceptable - Class 1,2,3

• Inside bend radii for coaxial cable is equal to or greater than five times the coax cable diameter (including insulation).

Figure 14-31


• Coaxial cable inside bend radius is less that five times the coax cable diameter (including insulation).

Figure 14-32

14-14

January 2002

IPC/WHMA-A-620


14.3.3 Wire Bundles – Unused Wire Termination Target - Class 1,2,3

• Ends of unused wires are covered with shrink sleeving. • Wire is folded back inside the sleeving. • Sleeving covers end of wire. • Unused wire is tied into the wire bundle.

Figure 14-33


• Ends of unused wires are covered with shrink sleeving. • Wire may extend straight down length of bundle without foldback (see Figure 14-34). • Sleeving extends at least two wire diameters beyond end of wire. • Sleeving extends on to the wire insulation for a minimum of four wire diameters or 6 mm [0.25 in], whichever is greater. • Unused wire is tied into the wire bundle.

Figure 14-34


• Ends of unused wires are exposed. • Unused wire is not tied into the wire bundle. Acceptable - Class 1 Process Indicator - Class 2 Defect - Class 3

• Insulating sleeving extends beyond end of wire less than two wire diameters and end of wire is not exposed. • Insulating sleeving extends onto wire insulation less than four wire diameters or 6 mm [0.25 in] whichever is greater. Figure 14-35

IPC/WHMA-A-620

January 2002

14-15


14.3.4 Wire Bundles – Ties over Splices and Ferrules Acceptable - Class 1,2,3

• Spot ties or straps are placed over or near splices contained in the wire bundle. • No stress on wires exiting splices.

Figure 14-36


• Spot ties or straps are placed over or near solder ferrules contained in the wire bundle. • No stress on wires exiting splices.

Figure 14-37


• Spot tie or strap is placing stress on the wire(s) exiting the splice.

Figure 14-38


• Spot tie or strap is placing stress on the wire(s) exiting the ferrule.

Figure 14-39

14-16

January 2002

IPC/WHMA-A-620

15 Harness/Cable Electrical Shielding

Shielding The following topics are addressed in this section:

15.4 Shield Termination - Splicing

15.1

15.5 Tapes - Barrier and Conductive, Adhesive or Non-Adhesive

15.1.1 15.1.2

Braided

Direct Applied Pre-Woven

15.6 Conduit (Shielding) 15.2 Shield Termination

15.2.1 15.2.2 15.2.3

Pick Off No Pick Off Low Temperature Insulated Wire - With Pick Off

15.7 Conductive Coating 15.8 Shrink Tubing - Conductive Lined

15.3 Shield Termination - Shrink and Crimp

IPC/WHMA-A-620

January 2002

15-1


15.1 Braided Metal braid shielding can either be woven directly over a core or obtained in prefabricated form and installed by sliding it over the wire bundle. All breakouts need to be properly secured prior to applying the braid. Figure 15-1 shows using tape to provide the breakouts. Lacing or cable ties may also be used, see 14 Securing/Harnessing. To prevent potential damage, (e.g., cold flow or shorting to) of the underlying wire, a separator such as the tape shown in Figure 15-2 needs to be applied over the wire bundle. Directly applied braid is to be back braided to lock weave. Pre-woven braids are to be secured at the ends by cable straps, spot ties, clamps (backshell type), or a potting material. When using cable straps or spot ties, fold the braid over itself, secure, and cover the end with heat shrink tubing or tape. Depending on final usage, pre-woven metallic braid may need to be cleaned to remove contamination prior to installation over the harness.

Figure 15-1

15-2

Figure 15-2

January 2002

IPC/WHMA-A-620


15.1.1 Braided – Direct Applied Target - Class 1,2,3

• Braid coverage meets drawing requirements. • Braiding is not so tight as to causes indention or distortion to the wires of the assembly. • Braid is free of loops. • All loose strands are trimmed flush and terminated with solder or tape. • No fraying or unraveling of braid ends. • No visible wire or shield braid through the fabric braid. • Braid strands smooth and evenly placed. • 38 mm [1.5 in] overlap of material at branches and breakouts. • Back braid lock stitch is a minimum of 13 mm [0.5 inch].

Defect - Class 2

• Braiding at breakouts and branches does not overlap. Defect - Class 2,3

• Braid strands bunched (excess overlap). • Braid coverage does not meet drawing requirements. • Wire or shield braid visible through braid. Defect - Class 3

• Braiding overlap less than 13 mm [0.5 in] at breakouts and branches. Figure 15-3

IPC/WHMA-A-620

January 2002

15-3


15.1.1 Braided – Direct Applied (cont.) Defect - Class 1,2,3

• Braid has loops. • Ends not secured, frayed or unraveling. • Tears and/or cuts of braiding. • Broken/end strands not trimmed.

Figure 15-4

Figure 15-5

15.1.2 Braided – Pre-Woven Target - Class 1,2,3

• Braid is smooth with firm contact against the wires. • Free of ballooning or bunching. • Ends secured with no fraying or unraveling. Defect - Class 1,2,3

• Ends not secured. • Tears and/or cuts of braiding. Defect - Class 2,3

• Ends frayed or unraveling. • Loose ends protruding from potting or shrink sleeving. Defect - Class 3

• Braid ballooned or bunched.

15-4

January 2002

IPC/WHMA-A-620


15.2 Shield Termination

15.2.1 Shield Termination – Pick Off Shield should terminate as close as possible to inner conductor termination point. Terminations made with self-sealing heat shrinkable devices shall be exempt from the cleaning requirements. Solder ferrules, including those supplied with an integral pick off wire, can be changed one size up or down to achieve correct fit.


• The solder preform (ring) is melted and a fillet is visible between shield and pick off. Shield and pick off lead contour is tinned and discernible (A). • Shield and pick off strip length are the same length and are lined up (B). • Meltable sealing rings have flowed. • Sleeve and wire insulation shows no discoloration due to excessive heat. • Shield weave pattern is intact.

Figure 15-6

Figure 15-7 1. Sleeve removed for clarity.

IPC/WHMA-A-620

January 2002

15-5


15.2.1 Shield Termination – Pick Off (cont.) Target - Class 1,2,3

• Solder ferrules used in a daisy chain application are staggered within the specified limits from the end of the wire (to minimize buildup). Note: Ferrules/splices may be located under clamps as long as protection is provided under the clamp, i.e., tape/sleeving or grommet.

Figure 15-8


• Shield used as a pick off, shield weave pattern is intact.

Figure 15-9


• Solder fillet has formed between the shield and pick off (see 4.8). • Shield and pick off lead is discernible.

Figure 15-10


15-6

January 2002

IPC/WHMA-A-620


15.2.1 Shield Termination – Pick Off (cont.) Acceptable - Class 1,2,3

• Strip length on braid and pick off does not exceed 6 mm [0.25 in] and is greater than 4 mm [0.15 in]. • Plastic sleeve is slightly discolored but not burned or charred. • Shield weave pattern is disturbed but a smooth concave solder fillet is visible. • Minimum solder fillet has formed between shield and pick off.

Figure 15-12



• Solder ferrules are staggered within the specified limits from end of wire. (Some ferrules are not staggered as much as target condition.)

Figure 15-14

IPC/WHMA-A-620

January 2002

15-7


15.2.1 Shield Termination – Pick Off (cont.) Acceptable - Class 1,2,3

• Shield used as a pick off, shield is combed out and re-twisted.


• Meltable sealing ring has flowed over the outside of the solder fillet but is not affecting the solder fillet.

Figure 15-16


• Pick off is not aligned with the stripped portion of the shield. • Solder fillet between pick off and shield does not meet requirements (see 4.8).

−

Figure 15-17


15-8

January 2002

IPC/WHMA-A-620


15.2.1 Shield Termination – Pick Off (cont.) Defect - Class 1,2,3

• Pick off wire extends beyond stripped surface of shield preventing wire from contacting shield (A). • Pick off lead has pierced the ferrule sleeve (B).

Figure 15-19



• Shield strand is protruding from end of ferrule (A). • Shield strand has pierced the sleeving (B).

Figure 15-21

IPC/WHMA-A-620

January 2002

15-9


15.2.1 Shield Termination – Pick Off (cont.) Defect - Class 1,2,3

• Insufficient solder flow, contour of solder preform is discernible.

Figure 15-22



• Plastic sleeve burned/charred, obscuring the solder connection.

Figure 15-24


• Ferrule is not properly positioned on the shield and bare shield is exposed.

Figure 15-25

15-10

January 2002

IPC/WHMA-A-620


15.2.2 Shield Termination – No Pick Off When the braid is not terminated it shall be covered with heat shrink sleeving.


• Exposed shield is less than 3 mm [0.12 in] in length (A). • Sleeving overlaps 6 mm [0.25 in] beyond the exposed shield in each direction (B). • Loose strands are not evident under the sleeving. • No discoloration on sleeving or wire insulation.

Figure 15-26


• Shield terminations are staggered within the specified limits from end of wire.

Figure 15-27


• Exposed shield is equal to or less than 3 mm [0.12 in]. • Sleeving or wire insulation may be discolored but may not be burned or charred.

Figure 15-28

IPC/WHMA-A-620

January 2002

15-11


15.2.2 Shield Termination – No Pick Off (cont.) Defect - Class 1,2,3

• Sleeving pierced by wire strand (not shown). Process Indicator - Class 1,2,3

• Stripped shield length exceeds 3 mm [0.12 in].

Figure 15-29


• Sleeving overlap is less than 6 mm [0.25 in]. • Sleeve or wire insulation is burned or charred. • Any split in sleeving (not shown).

Figure 15-30


• Sleeving is loose.

Figure 15-31

15-12

January 2002

IPC/WHMA-A-620


15.2.3 Shield Termination – Low temperature Insulated Wire – With Pick Off Target - Class 1,2,3

• Smooth, concave solder fillet between shield and pick off, Shield and pick off lead is tinned and is discernible. • Flux residue from cleanable flux has been removed prior to shrinking of the sleeving. • Sleeve and wire insulation shows no discoloration or melting. • Shield weave pattern is intact.

Figure 15-32


• Sufficient solder fillet has formed between the shield and pickoff lead, solder joint indicates minimum flow (A). • Strip length on shield and pick off does not exceed 6 mm [0.25 in] and is greater than 4 mm [0.15 in] (B). • Plastic sleeve is slightly discolored but not charred. • Shield weave pattern is disturbed but a properly wetted solder fillet is visible.

Figure 15-33

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January 2002

15-13


15.2.3 Shield Termination – Low temperature Insulated Wire – With Pick Off (cont.) Defect - Class 1,2,3

• Insulation is melted on the inner conductors. • Improperly wetted solder fillet (not shown).

Figure 15-34


• Insulation is melted on the outer jacket.

Figure 15-35


• Any split in sleeving.

Figure 15-36

15-14

January 2002

IPC/WHMA-A-620


15.3 Shield Termination – Shrink and Crimp Target - Class 1,2,3

• Shrinkable ring is shrunk (A). No movement of the ring or shield is evident. (Ring has lost its original color.) • Shield is visible between shrinkable ring and the backshell (B). • Shield is approximately 3 mm [0.12 in] from backshell (C). • Shield weave pattern is intact.

Figure 15-37


• Band is wrapped around the shield twice and clinched (A). No movement of the ring or shield is evident. • Sharp edges of the band cut off area have been removed (B) or covered with epoxy. • Shield is approximately 3 mm [0.12 in] from backshell (C). • Shield is visible between band and the backshell (D). • Shield weave pattern is intact.

Figure 15-38

IPC/WHMA-A-620

January 2002

15-15


15.3 Shield Termination – Shrink and Crimp (cont.) Acceptable - Class 1,2,3

• Shrinkable ring is shrunk (A). No movement of the ring or shield is evident. (Ring has lost its original color). • Shield is visible between shrinkable ring and the backshell (B). • Shield weave pattern is disturbed (not shown).

Figure 15-39


• Shield is against backshell and is visible between backshell and ring.

Figure 15-40

15-16

January 2002

IPC/WHMA-A-620


15.3 Shield Termination – Shrink and Crimp (cont.) Acceptable - Class 1,2,3

• Shield weave pattern is disturbed; gaps in weave pattern are present (A). • Shield is visible between ring and the backshell (B). • Crimp ring is crimped. No movement of the ring or shield is evident. • Shield strands not contained prior to the crimp ring are trimmed and do not exceed 10% of total strands.

Figure 15-41


• Crimp ring extends greater than 10% of the crimp ring length beyond backshell.

Figure 15-42

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January 2002

15-17


15.3 Shield Termination – Shrink and Crimp (cont.) Defect - Class 1,2,3

• Shield is not visible between shrinkable ring and backshell. • Shrinkable ring is not shrunk, movement of the ring and shield is evident. (Ring has retained its original color.)

Figure 15-43


• Shield extends beyond backshell crimp area (A). • Sharp edges are present in the band cut off area (B). • Shield strands not contained within crimp ring have not been trimmed (C). • Band is not wrapped around backshell two times.

Figure 15-44

15-18

January 2002

IPC/WHMA-A-620


15.3 Shield Termination – Shrink and Crimp (cont.) Defect - Class 1,2,3

• Backshell is damaged (A). • Shield is not visible at edge of crimp ring (B).

Figure 15-45

15.4 Shield Termination – Splicing Target - Class 1,2,3

• Tack solder is attaching all breakouts (arrows). • The spliced area is flexible. • Shield overlap is two times the diameter of the large (combined) wire bundle. • Shield weave pattern is undisturbed.

Figure 15-46

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January 2002

15-19


15.4 Shield Termination – Splicing (cont.) Acceptable - Class 1,2,3

• Tack solder is attaching all breakouts with sufficient solder flow. • Shield overlap is from one to three times the diameter of the large (combined) wire bundle.

Figure 15-47 Process Indicator - Class 1,2,3

• A solder fillet is present around the entire shield overlap area (arrow). • Shield overlap area is still flexible. • Shield weave pattern is disturbed.


• Tack solder has not flowed to inner shields (arrows). • Shield overlap is less than one times the diameter of the large (combined) wire bundle (not shown).


• Solder flow in the shield overlap area is excessive with no flexibility.

Figure 15-50

15-20

January 2002

IPC/WHMA-A-620


15.5 Tapes – Barrier and Conductive, Adhesive or Non-Adhesive Target - Class 1,2,3

• 50% overlap of tape. • Conforms to bundle. • Tape ends secured. Acceptable

• Meets requirements of Table 15-1. Table 15-1

Tape Overlap

Minimum Tape Overlap

Figure 15-51 Class 1

Class 2,3

25% of tape width

50% of tape width

Process Indicator - Class 1,2,3

• Tape does not conform to bundle. • Tape overlap not in conformance with Table 15-1. Defect - Class 1,2,3

• Tape loose or unraveling. • Ends not secure.

Figure 15-52

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January 2002

15-21


15.6 Conduit (Shielding) (Not illustrated.) Target - Class 1,2,3

• Conduit is free of dents, kinks or cracks. • No sharp edges or burrs at conduit ends. • If conduit is plated no base metal exposed. Acceptable - Class 1

• Cracks that do not expose wire bundle. Acceptable - Class 2

• Dents that do not compress or restrict passage of wire bundle. Defect - Class 2,3

• Any cracks. • Exposed base metal when plating is required. • Any kinks. • Sharp edges or burrs at conduit ends. Defect - Class 3

• Any dents or deformation.

15-22

January 2002

IPC/WHMA-A-620


15.7 Conductive Coating (Not illustrated.) Target - Class 1,2,3

• Conductive coating shows no loss of adhesion from the base material. • Coating is free of voids, bubbles, blisters, peeling or flaking. • Coating does not contain foreign material. Defect - Class 1,2,3

• Any foreign material in coating. • Any void, bubbles, blisters, adhesion loss, peeling or flaking. • Coating has not been applied to required areas. • Coating on areas required to be free of coating.

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January 2002

15-23


15.8 Shrink Tubing – Conductive Lined (Not illustrated.) Target - Class 1,2,3

• Tubing is tight on cable and connector/cable accessories. • No cracks or tears. • No overlapping of tubing. • Multiple pieces electrically connected. Acceptable - Class 1

• Tubing tight on connector/cable accessories, but not tight on cable. Defect - Class 1,2,3

• Tubing not tight on connector/cable accessory. • Cracks or tears in the tubing. • Multiple pieces not electrically connected. Defect - Class 3

• Tubing is not tight on cable.

15-24

January 2002

IPC/WHMA-A-620

16 Cable/Wire Harness Protective Coverings

Cable/Wire Harness Protective Coverings Protective coverings can take several forms and they may completely cover a cable harness or only selected portions. The primary purpose is abrasion resistance to protect internal wires. If woven, they can either be woven directly over a core or obtained in prefabricated form and installed by sliding it over the wire bundle. Other types of protective covering include heat shrink tubing, extruded jacket, spiral wrap sleeving, and taping. The following topics are addressed in this section: 16.1 Braid

16.1.1 16.1.2

Figure 16-1

Direct Applied Pre-Woven

16.2 Taping 16.3 Sleeving

16.3.1

Shrink Tubing

16.4 Spiral Plastic Wrap (Spiral Wrap Sleeving) 16.5 Conduit (Containment)

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January 2002

16-1


16.1 Braid

16.1.1 Braid – Direct Applied Fabric braids woven directly on interconnecting harnesses or cables may be loose or tight, as necessary to produce the degree of flexibility required. The braid shall be smooth and shall be free of gaps through which wires can be seen. No frayed ends shall be visible. All pigtails shall be secured. Braids applied tightly shall not terminate so close to connectors that they stress wires attached to solder cups or open connector sealing grommets. Spot ties, plastics straps, lacing and other temporary holding means shall be removed from wire bundles prior to braid application. Flat tapes may be left under braid if the tape has a low profile.

Figure 16-2


• Braiding is not so tight as to cause indention or distortion to the wires of the assembly. • No fraying or unraveling of braid ends. • Braid strands smooth and evenly placed. • 11⁄2 inch overlap of material at branches and breakouts. • Back braid lock stitch is a minimum of 13 mm [0.5 in].

Figure 16-3

16-2

January 2002

IPC/WHMA-A-620


16.1.1 Braid – Direct Applied (cont.) Acceptable - Class 2,3

• Small opening in overbraid but no visible wire through the fabric braid.

Figure 16-4


• Ends not secured. • Tears and/or cuts of braiding. • Broken/end strands not trimmed. Defect - Class 2,3

• Ends not secured, frayed or unraveling. Defect - Class 2

• Braiding at breakouts and branches does not overlap. Defect - Class 3

• Gap or absence of braid where coverage is required. • Wire or shield braid visible through braid. • Braiding overlap less than 13 mm [0.5 in] at breakouts and branches. Figure 16-5

IPC/WHMA-A-620

January 2002

16-3


16.1.2 Braid – Pre-Woven Pre-woven braid or sleeving is to be secured at the ends by spot ties, clamps, tape or heat shrink tubing. When secured, the covering will not slide freely. Adhesive, a hot knife or other process is used to prevent end fraying. For breakouts and branches the sleeving is not to be cut to allow passage of the wire. Depending on the weave the strands may be separated to allow wires to pass through. The number of wires is not to cause deformation or bunching of the sleeving.


• Ends not secured. • Tears and/or cuts of braiding. Defect - Class 2,3 Figure 16-6

• Ends not secured, frayed or unraveling. Defect - Class 3

• Loose ends protruding from potting or shrink sleeving. • Braid ballooned or bunched up.

Figure 16-7

16-4

January 2002

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16.2 Taping (Not Illustrated) Target - Class 1,2,3

• Tape is installed with a 50% overlap. • Tape does not bunch or add excessive bulk to bundle. • Ends are secured. Acceptable - Class 1

• Overlap is at least 25%. Acceptable - Class 2,3

• Overlap is at least 50%. Process Indicator - Class 2,3

• Tape overlap is less than 50%. Defect - Class 1,2,3

• Tape loose or unraveling. • Ends not secure. • Tape too tight causing indenture or distortion of bundle. Defect - Class 3

• Overlap causes excess bulk. • Tape is bunched.

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January 2002

16-5


16.3 Sleeving

16.3.1 Sleeving – Shrink Tubing (Not Illustrated) Target - Class 1,2,3

• Tubing is tight on cable and connector/cable accessories. • No cracks or tears. • Multiple pieces overlapped by at least 13 mm [0.5 in]. Acceptable - Class 1

• Tubing is tight on connector/cable accessories, but not tight on cable. Defect - Class 1,2,3

• Tubing is not tight on connector/cable accessory. • There are cracks or tears in the tubing. • Overlap is less than 13 mm [0.5 in].

16-6

January 2002

IPC/WHMA-A-620


16.4 Spiral Plastic Wrap (Spiral Wrap Sleeving) Spiral wrap sleeving is used for two purposes. One is to contain a group of wires/cables. Spiral wrap sleeving used for containment may or may not be overlapped and frequently the inner cables and wires are visible. The sleeving may be butted or applied as an open spiral. The other purpose is for abrasion protection. For this use, the sleeving needs to be overlapped (see 16.2). The ends of the spiral wrap need to be trimmed to eliminate sharp edges or points that might damage the insulation. When spiral sleeving is applied, the ends of the wire bundle need to be secured by string tie or other means. There are no illustrations for these criteria. Target - Class 1,2,3

• Spiral sleeving makes firm contact with the bundle. • Ends trimmed to eliminate sharp edges or points. • The sleeving is applied butt or open spiral, but does not overlap. • The ends of the wrap are secured. Defect - Class 2,3

• Ends not secured. • Ends have sharp edges or points. Defect - Class 3

• Spiral sleeving overlaps. Process Indicator - Class 1

• Ends have sharp edges or points.

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January 2002

16-7


16.5 Conduit (Containment) See 15.3.

16-8

January 2002

IPC/WHMA-A-620

17 Installation

Installation The following topics are addressed in this section: 17.1 General 17.2 Hardware Installation

17.2.1 17.2.2 17.2.3 17.2.4 17.2.5

Sequence Type and Missing Minimum Torque for Electrical Connections Wires High Voltage Applications

17.3 Wire/Harness Installation

17.3.1 17.3.2 17.3.3

Stress Relief Wire Dress Service Loops

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January 2002

17-1

17 Installation

17.1 General In many cases cable and wire harness assemblies are manufactured at one facility and shipped with or without end termination as a completed harness assembly to another facility where the harnesses are installed into an end-item (e.g., chassis, drawer or enclosure). This section provides acceptance criteria for installation of a harness. Mechanical assembly refers to mounting of assemblies requiring the use of any of the following: screws, bolts, nuts, washers, fasteners, clips, component studs, adhesives, tie downs, rivets, connector pins, etc. This section covers visual criteria. Compliance to torque requirements is to be verified as specified by customer documentation. Where the criteria are self-explanatory, no illustrations are provided. When no specific requirements have been established by other documentation, the following criteria apply. Acceptable - Class 1,2,3

• Wires and cables are positioned or protected to avoid contact with rough or irregular surfaces and sharp edges and to avoid damage to conductors or adjacent parts. • Minimum electrical clearance is maintained. • Installation hardware is tight, including applicable torque if required. • Wiring connections to ground are free of any protective finishes (e.g., paint, anodize coating, etc.) that can preclude an adequate ground connection. • Wire routing meets requirements for drip loops, no mechanical interference, etc. • Soldered connections meet the requirements of 4 Soldering. • Crimping meets the requirements of 5 Crimping. • Splice connections meet the requirements of 8 Splices. • Wiring is terminated at the destination specified by the wire marker/documentation. • Wire is not routed through ‘‘keep out’’ zones, e.g., hot surfaces or mechanical interference areas. • Adhesives are applied at the required location and properly cured. • Wire(s) not stressed. • Design cable wire/harness bend radius maintained. If not otherwise specified, the minimum bend radius is five to ten times the diameter of the wire or bundle, whichever is larger. • Wire and cable are supported with mounting hardware to preclude stress. • Cable ties, straps or clamps do not compress or damage wire insulation. • If required, a service loop is provided to allow at least one (1) field repair. Defect Class - 1,2,3

• Product that does not conform to the above criteria.

17-2

January 2002

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17 Installation

17.2 Hardware Installation This section illustrates several types of mounting hardware. Process documentation will specify what to use (drawings, prints, parts list, build process); deviations need to have prior customer approval. Visual inspection is performed in order to verify the following conditions: a. b. c. d. e.

Correct parts and hardware. Correct sequence of assembly. Correct security and tightness of parts and hardware. No discernible damage. Correct orientation of parts and hardware.

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January 2002

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17 Installation

17.2.1 Hardware Installation – Sequence A minimum of one and one half threads need to extend beyond the threaded hardware, (e.g., nut) unless otherwise specified by engineering drawing. Bolts or screws may be flush with the end of the threaded hardware only where threads could interfere with other components or wires and when locking mechanisms are used. Thread extension should not be more than 3.0 mm [0.12 in] plus one and one-half threads for bolts or screws up to 25 mm [0.984 in] long or more than 6.3 mm [0.248 in] plus one and one-half threads for bolts or screws over 25 mm [0.984 in]. This is providing that the extension does not interfere with any adjacent part and that the designed electrical clearance requirements are met.


• Proper hardware sequence. 1 2

3

4

2 3

4 1

Figure 17-1 1. 2. 3. 4.

Lock washer Flat washer Nonmetal Metal (not conductive pattern or foil)

17-4

January 2002

IPC/WHMA-A-620

17 Installation

17.2.1 Hardware Installation – Sequence (cont.) Defect - Class 1,2,3

• Hardware material or sequence not in conformance with drawing.

1

• Lock washer against nonmetal/laminate.

2

• Flat washer missing. 3

1

2

3

Figure 17-2 1. Lock washer 2. Nonmetal 3. Metal (not conductive pattern or foil)

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January 2002

17-5

17 Installation

17.2.2 Hardware Installation – Type and Missing Acceptable - Class 1,2,3

• Slot is covered with flat washer.

1

• Hole is covered with flat washer.

2 3

2

1 3

Figure 17-3 1. Slot or hole 2. Lock washer 3. Flat washer

Defect - Class 1,2,3 1

• Hardware missing or improperly installed.

2

Figure 17-4 1. Slot or hole 2. Lock washer

17-6

January 2002

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17 Installation

17.2.3 Hardware Installation – Minimum Torque for Electrical Connections When electrical connections are made using threaded fasteners they must be tight to ensure the reliability of the connection. When split-ring type lock washers are used, the threaded fastener must be tight enough to compress the lock washer. When required, fasteners are tightened to the specified minimum torque value.


• Fasteners are tight and split-ring lock washers, when used, are fully compressed. • Proper torque applied when torque is a requirement.

Figure 17-5


• Lock washer not compressed.

Figure 17-6

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January 2002

17-7

17 Installation

17.2.4 Hardware Installation – Wires When the use of terminal lugs is not required, wires are wrapped around screw type terminals in a manner that precludes loosening when the screw is tightened, and the ends of the wire are kept short to preclude shorting to ground or other current carrying conductors. If a washer is used, the wire/lead is to be mounted under the washer. Unless otherwise noted, all requirements apply to both stranded and solid wires.


• Strands of wire tightly twisted together (stranded wire). • Wire wrapped a minimum of 270° around the screw body. • Wire end secured under screw head. • Wire wrapped in the correct direction. • All strands are under screw head.

Figure 17-7

17-8

January 2002

IPC/WHMA-A-620

17 Installation

17.2.4 Hardware Installation – Wires (cont.) Acceptable - Class 1,2,3

• Wire wrapped around the screw body in the correct direction, but a few strands have unraveled in tightening the screw. • Less than 1⁄3 of the wire diameter protrudes from under the screw head. • Wire extending outside the screw head does not violate minimum electrical clearance. • Mechanical attachment of the wire is in contact between the screw head and the contact surface for a minimum of 180° around the screw head. • No insulation in the contact area. • Wire does not overlap itself.

Figure 17-8

Figure 17-9

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January 2002

17-9

17 Installation

17.2.4 Hardware Installation – Wires (cont.) Defect - Class 1,2,3

• Wire not wrapped around screw body (A). • Wire is overlapped (B). • Solid wire wrapped in wrong direction (C). • Stranded wire wrapped in wrong direction (tightening the screw unwinds the twisted wire) (D). • Insulation in the contact area (E). • Wire was tinned.

Figure 17-10

17-10

January 2002

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17 Installation

17.2.5 Hardware Installation – High Voltage Applications This section provides the unique requirements of mechanical assemblies that are subject to high voltages.


• There is no evidence of burrs or frayed edges on the hardware.

Figure 17-11


• Hardware has burrs or frayed edges.

Figure 17-12

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January 2002

17-11

17 Installation

17.3 Wire/Harness Installation

17.3.1 Wire/Harness Installation – Stress Relief


• The wire approaches the terminal with a loop or bend sufficient to relieve any tension on the connection during thermal/vibration stress.

Figure 17-13


• There is insufficient stress relief. • The wire is under stress at the wrap.

Figure 17-14

17-12

January 2002

IPC/WHMA-A-620

17 Installation

17.3.2 Wire/Harness Installation – Wire Dress Acceptable - Class 1,2,3

• The direction of the stress-relief bend places no strain on the mechanical wrap or the solder connection.

r

Figure 17-15


• The wire is formed around the terminal opposite to the feed-in direction.

Figure 17-16


• Bends are not kinked.

B

Figure 17-17


• Bends are kinked.

B

Figure 17-18

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January 2002

17-13

17 Installation

17.3.3 Wire/Harness Installation – Service Loops Acceptable - Class 1,2,3

• Sufficient service loop is provided to allow one field repair to be made.

Figure 17-19


• The wire is too short to allow an additional wrap if repair is necessary.

Figure 17-20

17-14

January 2002

IPC/WHMA-A-620

18 Solderless Wrap

Solderless Wrap This section establishes visual acceptability criteria for connections made by the solderless wrap method. It is assumed that the terminal/wire combination has been designed for this type of connection. It is also assumed that a monitoring system exists using test connections to verify that the operator/tooling combination is capable of producing wraps that meet strip force requirements. Depending on the service environment, the connecting instructions will specify whether the connection will be conventional or modified. Once applied to the terminal, an acceptable solderless wrap connection must not be subjected to excessive heat nor have any mechanical operations performed on it. No attempt to correct a defective connection by reapplying the wrapping tool or by applying other tools is to be made. The reliability and maintainability advantages of the solderless wrap connection method are such that no repair of a defective wrap by soldering is to be made.

The following topics are addressed in this section: 18.1 Number of Turns 18.2 Turn Spacing 18.3 End Tails, Insulation Wrap 18.4 Raised Turns Overlap 18.5 Connection Position 18.6 Wire Dress 18.7 Wire Slack 18.8 Plating 18.9 Damage

18.9.1 18.9.2

Insulation Wires and Terminals

The defective connections must be unwrapped using a special tool (not stripped off the terminal) then a new wire wrapped. New wire must be used for each rewrap, but the terminal post may be rewrapped.

IPC/WHMA-A-620

January 2002

18-1

18 Solderless Wrap

18.1 Number of Turns

1 2 3 456

7

For this requirement, countable turns are those turns of bare wire in intimate contact with the corners of the terminals starting at the first contact of bare wire with a terminal corner and ending at the last contact of bare wire with a terminal corner (see Table 18-1).

0

A modified wrap is required for Class 3. It has an additional amount of insulated wire wrapped to contact at least three corners of the terminal. Target - Class 1,2,3

Figure 18-1

• One half (50%) more turn than the minimum shown in Table 18-1. Acceptable - Class 1,2

• Countable turns meet the requirements of Table 18-1. Acceptable - Class 3

• Countable turns meet the requirements of Table 18-1 and there is an additional amount of insulated wire wrapped to contact at least three corners of the terminal. Table 18-1

Minimum Turns of Bare Wire

Wire Gauge (AWG)

Turns

28 - 34

7

26

6

24

5

22

5

20

4

18

4

Note: Maximum turns of bare and insulated wire is governed only by tooling configuration and space available on the terminal. Defect - Class 1,2,3

• Number of countable turns does not comply with Table 18-1.

18-2

January 2002

IPC/WHMA-A-620

18 Solderless Wrap

18.2 Turn Spacing Target - Class 1,2,3

• No space between any turns. 1 2 3 4 567

Figure 18-2 Acceptable - Class 1

• No space over one wire diameter. Acceptable - Class 2

• No space over 50% diameter of wire within countable turns; no space over one wire diameter elsewhere. Acceptable - Class 3

• No more than three turns spaced apart, not more than 50% wire diameter apart. Figure 18-3


• Any space over one wire diameter. Defect - Class 2

• Any space over half wire diameter within countable turns. Defect - Class 3

• Any space more than half wire diameter, more than three spaces any size.

Figure 18-4

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January 2002

18-3

18 Solderless Wrap

18.3 End Tails, Insulation Wrap Target - Class 1,2,3

• No wire clippings present. Target - Class 1,2

• End tail does not extend beyond outer surface of wrap. Insulation reaches terminal. Target - Class 3

• End tail does not extend beyond outer surface of wrap with insulation modified wrap (see 18.1).

Figure 18-5


• Insulation back and end tail any distance from outer surface, but does not violate clearance requirements to other circuitry. 2

Acceptable - Class 2 1 1

Figure 18-6 1. Insulation clearance 2. Wire diameter

• Insulation end meets clearance requirements to other circuitry and is not over 3.2 mm [0.125 in] from outer surface wrap. Acceptable - Class 3

• End tail projects no more than one wire diameter from outer surface of wrap. • Insulation must contact minimum of three corners of post.

18-4

January 2002

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18 Solderless Wrap

18.3 End Tails, Insulation Wrap (cont.) Acceptable - Class 1 Defect - Class 2,3

• End tail is greater than 3.2 mm [0.125 in]. Defect - Class 3

• End tail is greater than one wire diameter.

Figure 18-7


• End tail violates minimum electrical clearance requirements. • Any wire clippings.

Figure 18-8

IPC/WHMA-A-620

January 2002

18-5

18 Solderless Wrap

18.4 Raised Turns Overlap Raised turns are squeezed out of the helix and are no longer in contact with the terminal corners. Raised turns may overlap or override other turns.


• No raised turns.

Figure 18-9 Acceptable - Class 1

• Raised turns anywhere provided remaining total turns still in contact meet minimum turn’s requirement. Acceptable - Class 2

• No more than half turn raised within countable turns, any amount elsewhere. Acceptable - Class 3 Figure 18-10

• No raised turns within countable turns, any amount elsewhere.


• Remaining total turns still in contact do not meet minimum turn requirements • More than half raised turn within countable turns. Defect - Class 3

• Any raised turns within countable turns.

Figure 18-11

18-6

January 2002

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18 Solderless Wrap

18.5 Connection Position Target - Class 1,2,3

• All turns of each connection on working length of terminal, visible separation between each connection.

Figure 18-12


• Extra turns of bare wire or any turns of insulated wire (whether or not for modified wrap) beyond end of working length of terminal.

1


• Extra turns of bare wire or any turns of insulated wire overlap a preceding wrap. 2

Figure 18-13 1. Wrap extends above contact length 2. Insulation turn overlaps previous wrap


• Turns of insulated wire only overlap a preceding wrap. Acceptable - Class 3

• Wraps may have an insulated wire overlap the last turn of uninsulated wire. • No turns of bare or insulated wire beyond either end of working length.

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January 2002

18-7

18 Solderless Wrap

18.5 Connection Position (cont.) Defect - Class 1,2,3

• Any countable turns of bare wire off either end of working length. • Any countable minimum turns of bare wire overlapping wire turns of a preceding connection.

Figure 18-14

Figure 18-15

18-8

January 2002

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18 Solderless Wrap

18.6 Wire Dress Acceptable - Class 1,2,3 1

2

• Wire Dress: The dress of wire needs to be so oriented that force exerted axially on the wire will not tend to unwrap the connection, or to relieve the bite of wire on the corners of the terminal post. This requirement is satisfied when the wire is routed so as to cross the 45° line as shown.

45˚

Figure 18-16 1. Direction of turns 2. Proper radius

Defect - Class 1,2,3 1

• Wire Dress: Axially external forces on the wrap will cause the wrap to unwind or loosen the wire bite at the post corners.

2

45˚

Figure 18-17 1. Direction of turns

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January 2002

18-9

18 Solderless Wrap

18.7 Wire Slack Acceptable - Class 1,2,3

• Wiring needs to have sufficient slack so that it will not pull around corners of the other terminal posts or bridge and load other wires.

Figure 18-18


• Wire Slack: Insufficient wire slack causing: • Abrasion between wire insulation and wrap post. • Tension on wires between wrap post and possible distortion of posts. • Causing pressure on wires that are crossed by a taut wire.

1

Figure 18-19 1 Wire crossing

18-10

January 2002

IPC/WHMA-A-620

18 Solderless Wrap

18.8 Plating Tin or silver plating on the wire enhances the reliability of the connection. Copper wire used for solderless wrap is normally plated with tin or silver to improve joint reliability and minimize subsequent corrosion.


• After wrapping, uninsulated wire has no exposed copper. Acceptable - Class 1

• Countable turns may show exposed copper. Acceptable - Class 1,2

• Up to 50% of countable turns show exposed copper. Defect - Class 2

• More than 50% of countable turns show exposed copper. Figure 18-20

Defect - Class 3

• Any exposed copper (last half end and wire end excluded).

IPC/WHMA-A-620

January 2002

18-11

18 Solderless Wrap

18.9 Damage

18.9.1 Damage – Insulation


• After initial contact with post: • Insulation damage. • Splits. • Cut and fraying on the wrap.

1 Figure 18-21 1. Initial corner

Figure 18-22


• Minimum electrical spacing requirements are violated.

2

Defect - Class 2,3

• Splits, cuts or fraying of insulation between wrap terminals (prior to initial corner of post).

1

• Spacing requirements are violated. Figure 11-23 1. Initial corner 2. Split insulation, etc., between wrap terminal. Conductor is exposed.

18-12

January 2002

IPC/WHMA-A-620

18 Solderless Wrap

18.9.2 Damage – Wires and Terminals Target - Class 1,2,3 C B A

• Wire finish is not burnished or polished, nicked, scraped, gouged or otherwise damaged. • Wire wrap terminals shall not be burnished, scraped or otherwise damaged. Acceptable - Class 1,2,3

• Finish on the wire is burnished or polished (slight tool marks) (A). • The top or last turn damaged from the wrap tool such as nicks, scrapes, gouges, etc., not exceeding 25% of wire diameter (B). Figure 18-24

• Damage to terminal caused by tool such as burnishing, scraping, etc. (C). Acceptable - Class 1,2 Defect - Class 3

• Base metal is exposed on terminal.

IPC/WHMA-A-620

January 2002

18-13

18 Solderless Wrap


18-14

January 2002

IPC/WHMA-A-620

Appendix A

Terms and Definitions Definitions marked with an * are from IPC-T-50 Terms and Definitions for Interconnecting and Packaging Electronic Circuits. Additional terms and definitions applicable to cables and wire harnesses may be found in: SAE ARP 914A

Glossary of Electrical Connection Terms

SAE ARP 1931A ISO 8815

Glossary of Terms with Specific Reference to Electrical Wire and Cable.

Aircraft Electrical Cables and Cable Harnesses - Vocabulary, 1st Edition

American Wire Gage (AWG)

A standard system for designating wire diameter. Primarily used in the United States.

Ampacity

See current carrying capacity

Annealed Wire

Wire, which after final drawdown, has been heated and slowly cooled to remove the effects of cold working.

Armored Cable

A cable provided with a wrapping of metal, usually steel wires or tapes, primarily for the purpose of mechanical protection.

AWG Equivalent

The American Wire Gauge (AWG) round-conductor number that is used to designate a flat conductor with an equal cross-sectional area.

Bellmouth

The raised portion at the front and/or back of the wire barrel crimp that provides a gradual entrance and exit for the wire strands without causing damage.

Binder

A spirally served tape or thread used for holding assembled cable components in place awaiting subsequent manufacturing operations. (The IPC-T-50 ‘‘binder’’ definition is not applicable to this document.)

Boot

A form placed around wire termination of a multiple-contact connector to contain the liquid potting compound before it hardens. Also, a protective housing usually made from a resilient material to prevent entry of moisture into a connector. Can also be preformed, heat shrinkable and can be purchased with self-adhesive or bonded with an adhesive.

Braid

Woven bare metallic or tinned copper wire used as shielding for wires and cables and as ground wire for batteries or heavy industrial equipment. Also, a woven fibrous protective outer covering over a conductor or cable.

Braid Angle

The smaller of the two angles formed by the shielding strand the axis of the cable being shielded.

Braid Carrier

A spool or bobbin on a braider which holds one group of strands or filaments consisting of a specific number of ends. The carrier revolves during braiding operations.

Braid Ends

The number of strands used to make up one carrier. The strands are wound side by side on the carrier bobbin and lie parallel in the finished braid.

Breakdown Voltage

The voltage at which the insulation between two conductors ruptures

Breakout

The point at which a conductor or group of conductors is separated from a multiconductor cable or wiring harness to complete circuits at other points.

BusBar Wire

Uninsulated tinned copper wire used as a common lead.

Butt Splice

Device for joining conductors by butting them end to end.

Cable

A group of individually insulated conductors in twisted or parallel configuration under a common sheath.

Cable, Assembly

A cable with plugs or connectors attached.

Cable, Camber

*The planar deflection of a flat cable or flexible laminate from a straight line.

IPC/WHMA-A-620

January 2002

A-1

Appendix A

Terms and Definitions (cont.) Cable, Clamp

A device used to give mechanical support to the wire bundle or cable at the rear of a plug or receptacle.

Cable, Coaxial

(1) A cable consisting of two cylindrical conductors with a common axis separated by a dielectric. (2) *A cable in the form of a central wire surrounded by a conductor tubing or sheathing that serves as a shield and return.

Cable, Flat

(1) Any cable with two smooth or corrugated but essentially flat surfaces. (2) *Two or more parallel, round or flat, conductors that are contained in the same plane of a flat insulating base material.

Cable, Flat Conductor

A planar construction with two or more flat conductors.

Cable, Flat, Margin

*The distance between the reference edge of a flat cable and the nearest edge of the first conductor.

Cable, Reference Edge

*The edge of a cable or conductor from which measurements are made.

Cable, Ribbon

(1) A flat cable of individually insulated conductors lying parallel and held together by means of adhesive film laminate. (2) *A flat cable with round conductors.

Cable, Transmission

*Two or more transmission lines in the form of an interconnection-wiring cable.

Cable/Harness, Indoor Use

(Also Harness) Product intended and designed for indoor use only.

Cable/Harness, Outdoor Use

(Also Harness) Outdoor Use Cables/Harnesses: Product expected to withstand exposure to the elements of weather.

Camber

*The planar deflection of a flat cable or flexible laminate from a straight line.

Circular Mil

The area of a circle one mil [0.001 in] in diameter; 7.845 x 10-7 sq. in. Used in expressing wire cross sectional area.

Circular Mil Area

Cross-sectional area of a current carrying portion of a conductor expressed in circular mils.

Circumferential Crimp

Final configuration of a terminal barrel made when crimping dies completely surround the barrel and form symmetrical indentations.

Closing

An operation where all leads are to be covered and the jacket insulation is captured by a type of hood or cover.

CMA

See Circular Mil Area

Cold Flow

Deformation of the insulation as a result of mechanical force or pressure (not due to heat softening).

Compression Connector

Connector crimped by an externally applied force; the conductor is also crimped by such force inside the tube-like connector body. Compression connectors are in very intimate contact with the two ends of the conductors being spliced.

Concentricity

In a wire or cable, concentricity is the measurement of the location of the center of the conductor with respect to the geometric center of the surrounding insulation.

Conductor

An uninsulated wire or the conductor of an insulated wire suitable for carrying electrical current.

Conductor, Flat

*A rectangular conductor that is wider than it is high.

Conduit

A tube in which insulated wires and cables are passed.

Connector

(1) A device used to physically and electrically join two or more conductors. (2) *A device used to provide mechanical connect/disconnect service for electrical terminations.

Contact

The conducting part of a connector that acts with another such part to complete or break a circuit.

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January 2002

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Appendix A

Terms and Definitions (cont.) Contact Angle (Bonding)

*The angle between the bonding lead or wire and the bonding land.

Contact Angle (Soldering)

*The angle of a solder fillet that is enclosed between a plane that is tangent to the solder/basis-metal surface and a plane that is tangent to the solder/air interface (see Figure 4-41).

Contact Area

*The common area between a conductor and a connector through which the flow of electricity takes place.

Contact Length

*The distance of travel made by a contact in touch with another during the insertion and removal of a connector.

Contact Resistance

*The electrical resistance of metallic surfaces, under specified conditions, at their interface in the contact area.

Contact Retention

The maximum axial load in either direction that a contact must withstand while remaining firmly fixed in its normal position within the connector insert or housing.

Contact Retention Force

*The minimum axial load in either direction that a contact withstands while it is in its normal position in a connector insert.

Contact Size

Defines the largest size wire that can be used with the specific contact. By specification dimensioning, it also defines the diameter of the engagement end of the pin.

Continuity

(1) A continuous path for the flow of current in an electrical circuit. (2) *An uninterrupted path for the flow of electrical current in a circuit.

Core

In cables, a component or assembly of components over which additional components (shield, sheath, etc.) are applied.

Corona

A discharge due to ionization of air around a conductor due to a potential gradient exceeding a certain critical value.

Coupling Ring

A device used on cylindrical connectors to lock a plug and receptacle together.

Creep

(1) The dimensional change with time of a material under load. (2) *Time-dependent strain occurring under stress.

Crimp

Final configuration of a terminal barrel formed by the compression of terminal barrel and wire.

Crimp Height

A measurement taken of the overall wire barrel height after the terminal has been crimped.

Cut Off Tab

The small tabs that remain on the front and back of a terminal after it has been applied.

Daisy Chain

Connections in series that render all of the connections common.

Dielectric

(1) Any insulating medium that intervenes between two conductors. (2) *A material with a high resistance to the flow of direct current, and which is capable of being polarized by an electrical field.

Dielectric Breakdown

*The complete failure of a dielectric material that is characterized by a disruptive electrical discharge through the material that is due to deterioration of material or due to an excessive sudden increase in applied voltage.

Dielectric Strength

*The maximum voltage that a dielectric can withstand under specified conditions without resulting in a voltage breakdown, usually expressed as volts per unit dimension. Also called Disruptive Gradient of Electric Strength.

Dielectric Withstanding Voltage

Maximum potential gradient that a dielectric material can withstand without failure.

Discontinuity

(1) A broken connection, or the loss of a specific connection characteristic.

IPC/WHMA-A-620

January 2002

A-3

Appendix A

Terms and Definitions (cont.) Dot Coding

Process of tool imprinting a 22-10 AWG PIDG terminal. Dot coding indicates whether the proper tool has been used.

Double Crimp

The process of two or more mechanical crimping operations on the same location in a single terminal.

Drain Wire

In a cable, the uninsulated wire in intimate contact with a shield to provide for easier termination of such a shield.

Electromagnetic Compatibility (EMC)

Describes a device’s ability to function properly in the customer’s environment without causing electromagnetic interference to other equipment, or itself being susceptible to external interference.

Electromagnetic Interference (EMI)

(1) The Undesirable electromagnetic emissions from a product, which can interfere with the proper operation of other devices. (2) *Unwanted radiated electromagnetic energy that couples into electrical conductors.

EMC

See electromagnetic compatibility.

EMI

See electromagnetic interference.

End Bell

An accessory similar to a cable clamp that attaches to the back of a plug or receptacle. It serves as an adaptor for the rear of connectors.

End Cap Splice

An insulated splice in which two or more wires overlap and enter the splice from the same end of the barrel.

Ferrule

(1) A short tube. Used to make solderless connections to shielded or coaxial cable. (2) An item molded into the plastic inserts of multiple contact and fiber optic connectors to provide strong, wear-resistant shoulders on which contact retaining springs can bear. (3) A terminal crimped onto stranded wire to allow insertion into terminal blocks.

Filler

(1) A material used in multiconductor cables to occupy voids formed by the assembled conductors. (2) An inert substance added plastics to improve properties or decrease cost. (3) *A substance that is added to a material to improve its solidity, bulk, or other properties.

Gas-Tight

(1) The characteristic of a contact that is impervious to ingress by corrosive gases. (2) *The common area between mated-metal surfaces from which gas vapors and impurities are excluded.

Grommet

A rubber seal used on the cable side of multiple contact connector to seal the connector against moisture, dirt or air.

Harness

A group of wires and cables, usually made with breakouts, which are tied together or pulled into a rubber or plastic sheath. A harness provides interconnection of an electric circuit.

Harness, Indoor Use

(Also Cable) Product intended and designed for indoor use only.

Harness, Outdoor Use

(Also Cable) Outdoor Use Cables/Harnesses: Product expected to withstand exposure to the elements of weather.

Hipot Test

(1) A test designed to verify the integrity of a wire’s insulation when subjected to high voltage. (2) *A method in which the unit under test is subjected to a high alternating current (AC) voltage.

Hood

A type of cover used to enclose wires that are assembled into a connector.

Hook-Up Wire

A single insulated conductor used for low current, low voltage (usually under 1000 volts) applications within enclosed electronic equipment.

Hot Stamping

Permanent markings in letters or numbers that are stamped by heat under pressure onto wire.

Hygroscopic

The characteristic of a material to absorb moisture from the air.

IDC

See insulation displacement connector.

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January 2002

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Appendix A

Terms and Definitions (cont.) Insert, Connector

*The element that holds connector contacts in their proper arrangement and electrically insulates the contacts from one another and from the connector shell.

Insert Retention

Axial load in either direction that an insert must withstand without being dislocated from its normal position in the connector shell.

Insertion Force

The effort, usually measured in ounces, required to engage mating components.

Insertion Tool

A small, hand-held tool used to insert contacts into a connector.

Insulation

A material that offers high electrical resistance making it suitable for covering components, terminals and wires to prevent the possible future contact of adjacent conductors resulting in a short circuit.

Insulation Crimp

Area of a terminal, splice or contact that has been formed around the insulation of the wire.

Insulation Displacement Connector (IDC)

A mass termination connector for flat cable with contacts that displace the conductor insulation to establish simultaneous contact with all conductors.

Insulation Resistance

*The electrical resistance of an insulating material that is determined under specific conditions between any pair of contacts, conductors, or grounding devices in various combinations.

Insulation Support

An extension of the rear portion of the contact that gives the wire side support, but not longitudinal support. This section is not crimped.

Insulation Thickness

The wall thickness of the applied insulation.

Insulator

*A material with a high resistance to the flow of electrical current. (See also ‘‘Dielectric.’’)

Interconnection

Mechanically joining devices together to complete an electrical circuit.

Interstices

Voids or valleys between individual strands in a conductor or between insulated conductors in a multiconductor cable during extreme flexing.

Jacket

An outer covering, usually non-metallic, mainly used for protection against the environment.

Jackscrew

A screw attached to one half of a two-piece, multiple-contact connector and used to draw both halves together and to separate them.

Jumper Cable

A short flat cable interconnecting two wiring boards or devices.

Keying

Mechanical arrangement of guide pins and sockets, keying plugs, contacts, bosses, slots, keyways, inserts or grooves in a connector housing shell or insert that allows connectors of the same size and type to be lined up without the danger of making a wrong connection.

Keying Plug Contact

A component that is inserted into a cavity of a connector housing or insert to assure engagement of identically matched components.

Kinked

An abrupt bend from which a wire strand is not easily restored to its original condition.

Lacing Cord or Twine

Used for lacing and tying cable forms, hook-up wires, cable ends, cable bundles and wire harness assemblies. Available in various materials and impregnants.

Lanyard

A device attached to certain connectors that permits uncoupling and separation of connector halves by a pull on a wire or cable.

Lap Joint

Two conductors joined by placing them side by side so that they overlap. See Parallel Splice.

Lead

(1) A wire, with or without terminals, that connects two points in a circuit. (2) *A length of insulated or uninsulated metallic conductor that is used for electrical interconnections.

Locator

Device for positioning terminals, splices or contacts in crimping dies.

Lug

A wire terminal.

IPC/WHMA-A-620

January 2002

A-5

Appendix A

Terms and Definitions (cont.) Mastic

A meltable coating used on the inside of some shrink products which when heated flows to encapsulate the interstitial air voids.

Mate

To join two connector halves in a normal engaging mode.

MCM

One thousand circular mils.

Multiple-Conductor Cable

A combination of two or more conductors cabled together and insulated from one another and from sheath or armor where used.

Nest

Part of a crimping die set, the nest provides the location and support for the terminal barrel as it is being deformed into the desired crimp configuration by the indentor. Also called Anvil.

O Crimp

An insulation support crimp for open barrel terminals with a crimped form resembling an O. It conforms to the shape of round wire insulation.

Parallel Splice

A parallel splice is a device for joining two or more conductors in which the conductors lie parallel and adjacent. See Lap Joint.

Pick

Distance between two adjacent crossover points of braid filaments. The measurement in picks per inch indicates the degree of coverage.

Pitch

(1) In flat cable, the nominal distance between the index edges of two adjacent conductors. (2) *The nominal center-to-center distance of adjacent conductors. (When the conductors are of equal size and their spacing is uniform, the pitch is usually measured from the reference edge of the adjacent conductors.)

Plenum

The air return path of a central air handling system, either ductwork or open space over a dropped ceiling.

Plenum Cable

Cable approved by Underwriters Laboratories for installation in plenums without the need for conduit.

Plug

The part of the two mating halves of a connector that is free to move when not fastened to the other mating half.

Polarization

Polarization is a mechanical arrangement of inserts and/or shell configuration (referred to as clocking in some instances) that prohibits the mating of mismatched plugs and receptacles. This is to allow connectors of the same size to be lined up, side by side, with no danger of making the wrong connection.

Polarizing Pin

A pin located on one half of a two-piece connector in such a position that by mating with an appropriate hole on the other half during assembly of the connector, it will assure that only related connector halves can be assembled.

Polarizing Slot

*A slot in the edge of a printed board that is used to assure the proper insertion and location of the board in a mating connector. (See also ‘‘Keying Slot.’’)

Positioner

A device attached to the crimping tool to position conductor barrel between the indentors.

Potting

Sealing of a component (e.g., the cable end of a multiple contact connector) with a plastic compound or material to exclude moisture, prevent short circuits and provide strain relief.

Potting Compound

*A material, usually organic, that is used for the encapsulation of components and wires.

Potting Cup

An accessory that, when attached to the rear of a plug or receptacle, provides a pouring form for potting the wires and the wire entry end of the assembly.

Potting Mold

An item, solid or split, designed to be used as a hollow form into which potting compound is injected and allowed to cure or set to seal the back of an electrical connector.

Ratchet Control

A ratchet control is a device to ensure the full crimping cycle of a crimping tool.

Ratchet Hand Tool

Tool designed with ratchet device to insure completion of the crimping cycle.

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January 2002

IPC/WHMA-A-620

Appendix A

Terms and Definitions (cont.) Recovered Diameter

Diameter of shrinkable products after heating has caused it to return to its extruded diameter.

Reference Edge

*The edge of a cable or conductor from which measurements are made.

RF Connector

Connector used for connecting or terminating coaxial cable.

RFI

Abbreviation for radio frequency interference.

RG/U

Abbreviation for Radio Government Universal, RG is the military designation of coaxial cable in MILC-17 and U stands for ‘‘general utility.’’

Ribbon Cable

See cable, ribbon.

Ring Tongue Terminal

Round-end tongue terminal with hole to accommodate screw or stud.

Sealing Plug

A plug that is inserted to fill an unoccupied contact aperture in a connector insert. Its function is to seal, especially in environmental connectors.

Sheath

The outer covering or jacket of a multiconductor cable.

Shell

The outside case of connector into which the insert and contacts are assembled.

Shield

(1) A metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields. (2) *The material around a conductor or group of conductors that limits electromagnetic and/or electrostatic interference.

Shield Adapter

An intermediate device that allows the termination of the cable shield to the connector shell.

Shield Coverage

The physical area of a cable that is covered by the shielding material and is expressed in percent.

Shielding, Electronic

*A physical barrier, that is usually electrically conductive, that reduces the interaction of electric or magnetic fields upon devices, circuits, or portions of circuits.

Solder Terminal

*An electrical/mechanical connection device that is used to terminate a discrete wire or wires by soldering. (See also ‘‘Solder Terminal, Bifurcated,’’ ‘‘Cup Solder Terminal,’’ ‘‘Hook Solder Terminal,’’ ‘‘Perforated (Pierced) Solder Terminal,’’ and ‘‘Turret Solder Terminal.’’)

Solder Terminal, Bifurcated

*A solder terminal with a slot or slit opening through which one or more wires are placed prior to soldering.

Solder Terminal, Cup

*A cylindrical solder terminal with a hollow opening into which one or more wires are placed prior to soldering.

Solder Terminal, Hook

*A solder terminal with a curved feature around which one or more wires are wrapped prior to soldering.

Solder Terminal, Perforated (Pierced)

*A flat-metal solder terminal with an opening through which one or more wires are placed prior to soldering.

Solder Terminal, Turret

*A round post-type stud (stand-off) solder terminal with a groove or grooves around which one or more wires are wrapped prior to soldering.

Solderless Contact

A contact with a back portion that is a hollow cylinder which allows it to accept a wire. After a bared wire is inserted, a crimping tool is applied to crimp the contact metal firmly against the wire. Usually called a crimp contact.

Solderless Wrap

*The connecting of a solid wire to a square, rectangular, or V-shaped terminal by tightly wrapping a solid-conductor wire around the terminal with a special tool.

Splice

(1) A joint connecting conductors with good mechanical strength and which provide good conductivity. (2) A terminal that permanently joins two or more wires.

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January 2002

A-7

Appendix A

Terms and Definitions (cont.) Strain Relief

A technique or item which reduces the transmission of mechanical stresses to the conductor termination.

Strain Relief Connector

*A receptacle connector device that prevents the disturbance of the contact and cable terminations.

Strain Relief Clamp

An adjustable collar, usually secured by a nut and bolt, that clamps the wire or cable attached to the connector so as to relieve the strain on the contact terminations. See Cable Clamp.

Strands, Nicked

Nicked strands have been partially cut or broken but are still attached. Severed strands have been cut or broken to where they are no longer attached.

Strands, Scraped

Strands have been damaged due to a stripping instrument removing material from strand.

Stress Relief

(1) A predetermined amount of slack to relieve tension in component or lead wires. (2) *The portion of a component lead or wire lead that is formed in such a way as to minimize mechanical stresses after the lead is terminated.

Tab

(1) The flat blade portion of certain terminals. (2) On strip terminals, the projection that results when the point-of-shear is not flush with the terminal body (i.e., cut-off tab).

Tensile

Amount of axial load required to break or pull a wire from the crimped barrel of a terminal, splice or contact.

Tensile Strength

The pull stress required to break a given specimen.

Terminal

(1) A device designed to terminate a conductor that is to be affixed to a post, stud, chassis, another conductor, etc., to establish an electrical connection. Some types of terminals include ring, tongue, spade, flag, hook, blade, quick-connect, offset and flanged. (2) *A metallic device that is used for making electrical connections. (See also ‘‘Solder Terminal.’’)

Thermocouple

A device consisting of two dissimilar metals in physical contact, which when heated will develop an EMF output.

Tinned Copper

Tin coating added to copper to aid in soldering and inhibit corrosion.

Tinning

*The application of molten solder to a basis metal in order to increase its solderability.

Tracer Stripe

When more than one color-coding stripe is required, the first (widest) stripe is the base stripe, the others usually narrower stripes, being termed tracer stripes.

Tray Cable

A factory-assembled multiconductor or multi-pair control, signal or power cable specifically approved under the National Electrical Code for installation in trays.

Tubing

A tube of extruded non-supported plastic or metallic material.

Wetting, Solder

*The formation of a relatively uniform, smooth, unbroken, and adherent film of solder to a basis metal.

Wire

A wire is a slender rod or filament of drawn metal.

Wire Diameter

The overall conductor plus insulation thickness.

Wire Wrap

See solderless wrap.

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January 2002

IPC/WHMA-A-620

Appendix B

Metric Conversion Table micrometers (microns)

mm

inch

micrometers (microns)

9.0

0.0090

0.00036

FIVE DECIMAL PLACES

mm

inch

FOUR DECIMAL PLACES (cont.)

0.05

0.00005

0.000002

0.06

0.00006

0.000002

9.5

0.0095

0.00038

0.07

0.00007

0.000003

10.0

0.0100

0.00040

0.08

0.00008

0.000003

10.5

0.0105

0.00041

0.09

0.00009

0.000004

11.0

0.0110

0.00043

0.10

0.00010

0.000004

11.5

0.0115

0.00045

0.11

0.00011

0.000004

12.0

0.0120

0.00047

0.12

0.00012

0.000005

12.5

0.0125

0.00050

0.13

0.00013

0.000005

13.0

0.0130

0.00050

0.14

0.00014

0.000006

13.5

0.0135

0.00053

0.15

0.00015

0.000006

0.20

0.00020

0.000008

1

0.001

0.00004

0.25

0.00025

0.000010

2

0.002

0.00008

THREE DECIMAL PLACES

FOUR DECIMAL PLACES

3

0.003

0.00012

0.1

0.0001

4

0.004

0.00016

0.2

0.0002

0.00001

5

0.005

0.00020

0.3

0.0003

0.00001

6

0.006

0.00024

0.4

0.0004

0.00002

7

0.007

0.00028

0.5

0.0005

0.00002

8

0.008

0.00032

0.6

0.0006

0.00002

9

0.009

0.00036

0.7

0.0007

0.00003

10

0.010

0.00040

0.8

0.0008

0.00003

11

0.011

0.00043

0.9

0.0009

0.00004

12

0.012

0.00047

1.0

0.0010

0.00004

13

0.013

0.00050

1.1

0.0011

0.00004

14

0.014

0.00055

1.2

0.0012

0.00005

15

0.015

0.00060

1.3

0.0013

0.00005

20

0.020

0.00080

1.4

0.0014

0.00006

25

0.025

0.00100

1.5

0.0015

0.00006

30

0.030

0.00120

2.0

0.0020

0.00008

35

0.035

0.00140

2.5

0.0025

0.00010

40

0.040

0.00160

3.0

0.0030

0.00012

45

0.045

0.00180

3.5

0.0035

0.00014

50

0.050

0.00200

4.0

0.0040

0.00016

55

0.055

0.00220

4.5

0.0045

0.00018

60

0.060

0.00240

5.0

0.0050

0.00020

65

0.065

0.00260

5.5

0.0055

0.00022

70

0.070

0.00280

6.0

0.0060

0.00024

75

0.075

0.00300

6.5

0.0065

0.00026

80

0.080

0.00320

7.0

0.0070

0.00028

85

0.085

0.00340

7.5

0.0075

0.00030

90

0.090

0.00360

8.0

0.0080

0.00032

95

0.095

0.00380

8.5

0.0085

0.00034

100

0.100

0.00400

IPC/WHMA-A-620

January 2002

B-1

Appendix B

Metric Conversion Table (cont.) micrometers (microns)

mm

inch


1000

THREE DECIMAL PLACES (cont.) 105

0.105

0.00410

110

0.110

115

0.115

120

inch

TWO DECIMAL PLACES (cont.) 1.00

0.0400

0.00430

1.05

0.0410

0.00450

1.10

0.0430

0.120

0.00470

1.15

0.0450

125

0.125

0.00500

1.20

0.0470

130

0.130

0.00500

1.25

0.0500

0.135

0.00530

1.30

0.0500

1.40

0.0550

135

TWO DECIMAL PLACES

B-2

mm

10

0.01

0.0004

1.50

0.0600

20

0.02

0.0008

1.60

0.0630

30

0.03

0.0012

1.70

0.0670

40

0.04

0.0016

1.80

0.0700

50

0.05

0.0020

1.90

0.0750

60

0.06

0.0024

2.00

0.0800

70

0.07

0.0028

2.10

0.0830

80

0.08

0.0032

2.20

0.0870

90

0.09

0.0036

2.30

0.0900

100

0.10

0.0040

2.40

0.0950

110

0.11

0.0043

2.50

0.1000

120

0.12

0.0047

2.60

0.1030

130

0.13

0.0050

2.70

0.1050

140

0.14

0.0055

2.80

0.1100

150

0.15

0.0060

2.90

0.1150

160

0.16

0.0063

3.00

0.1200

170

0.17

0.0067

3.10

0.1230

180

0.18

0.0070

3.20

0.1250

190

0.19

0.0075

3.30

0.1300

200

0.20

0.0080

3.40

0.1330

250

0.25

0.0100

3.50

0.1370

300

0.30

0.0120

3.60

0.1400

350

0.35

0.0140

3.70

0.1450

400

0.40

0.0160

3.80

0.1500

450

0.45

0.0180

3.90

0.1530

500

0.50

0.0200

4.00

0.1570

550

0.55

0.0220

4.10

0.1600

600

0.60

0.0240

4.20

0.1650

650

0.65

0.0260

4.30

0.1700

700

0.70

0.0280

4.40

0.1730

750

0.75

0.0300

4.50

0.1770

800

0.80

0.0320

4.60

0.1800

850

0.85

0.0340

4.70

0.1850

900

0.90

0.0360

4.80

0.1900

950

0.95

0.0380

4.90

0.1930

January 2002

IPC/WHMA-A-620

Appendix B


mm

inch


TWO DECIMAL PLACES (cont.)

IPC/WHMA-A-620

mm

inch

TWO DECIMAL PLACES (cont.)

5.00

0.1970

9.30

0.3650

5.10

0.2000

9.40

0.3700

5.20

0.2050

9.50

0.3750

5.30

0.2100

9.60

0.3770

5.40

0.2130

9.70

0.3800

5.50

0.2170

9.80

0.3850

5.60

0.2200

9.90

0.3900

5.70

0.2250

10.00

0.3930

5.80

0.2300

ONE DECIMAL PLACE

5.90

0.2330

0.1

0.004

6.00

0.2350

0.2

0.008

6.10

0.2400

0.3

0.012

6.20

0.2450

0.4

0.016

6.30

0.2500

0.5

0.020

6.40

0.2500

0.6

0.024

6.50

0.2550

0.7

0.028

6.60

0.2600

0.8

0.032

6.70

0.2630

0.9

0.036

6.80

0.2670

1.0

0.040

6.90

0.2700

1.1

0.043

7.00

0.2750

1.2

0.047

7.10

0.2800

1.3

0.050

7.20

0.2830

1.4

0.055

7.30

0.2870

1.5

0.060

7.40

0.2900

2.0

0.080

7.50

0.2950

2.5

0.100

7.60

0.3000

3.0

0.120

7.70

0.3030

3.5

0.140

7.80

0.3070

4.0

0.160

7.90

0.3100

4.5

0.180

8.00

0.3150

5.0

0.200

8.10

0.3200

5.5

0.220

8.20

0.3230

6.0

0.240

8.30

0.3270

6.5

0.260

8.40

0.3300

7.0

0.280

8.50

0.3350

7.5

0.300

8.60

0.3400

8.0

0.320

8.70

0.3400

8.5

0.340

8.80

0.3450

9.0

0.360

8.90

0.3500

9.5

0.380

9.00

0.3550

10.0

0.400

9.10

0.3600

10.5

0.410

9.20

0.3630

11.0

0.430

January 2002

B-3

Appendix B


mm

inch


ONE DECIMAL PLACE (cont.)

inch

NO DECIMAL PLACES (cont.)

11.5

0.450

15

0.60

12.0

0.470

20

0.80

12.5

0.500

25

1.00

13.0

0.500

30

1.20

NO DECIMAL PLACES

B-4

mm

35

1.40

1

0.04

40

1.60

2

0.08

45

1.80

3

0.12

50

2.00

4

0.16

55

2.20

5

0.20

60

2.40

6

0.24

65

2.60

7

0.28

70

2.80

8

0.32

75

3.00

9

0.36

80

3.20

10

0.40

85

3.40

11

0.43

90

3.60

12

0.47

95

3.80

13

0.50

100

4.00

14

0.55

January 2002

IPC/WHMA-A-620

ASSOCIATION CONNECTING ELECTRONICS INDUSTRIES ®

Standard Improvement Form The purpose of this form is to provide the Technical Committee of IPC with input from the industry regarding usage of the subject standard.

Individuals or companies are invited to submit comments to IPC. All comments will be collected and dispersed to the appropriate committee(s).

IPC/WHMA-A-620 If you can provide input, please complete this form and return to: IPC 2215 Sanders Road Northbrook, IL 60062-6135 Fax 847 509.9798 E-mail: [email protected]

1. I recommend changes to the following: Requirement, paragraph number Test Method number

, paragraph number

The referenced paragraph number has proven to be: Unclear

Too Rigid

In Error

Other

2. Recommendations for correction:

3. Other suggestions for document improvement:

Submitted by: Name

Telephone

Company

E-mail

Address City/State/Zip

Date

ASSOCIATION CONNECTING ELECTRONICS INDUSTRIES ®

The purpose of this form is to keep current with terms routinely used in the industry and their definitions. Individuals or companies are invited to comment. Please complete this form and return to: IPC 2215 Sanders Road Northbrook, IL 60062-6135 Fax: 847 509.9798

ANSI/IPC-T-50 Terms and Definitions for Interconnecting and Packaging Electronic Circuits Definition Submission/Approval Sheet SUBMITTOR INFORMATION: Name: Company: City: State/Zip: Telephone: Date:

❑ This is a NEW term and definition being submitted. ❑ This is an ADDITION to an existing term and definition(s). ❑ This is a CHANGE to an existing definition. Term

Definition

If space not adequate, use reverse side or attach additional sheet(s).

Artwork: ❑ Not Applicable ❑ Required ❑ To be supplied ❑ Included: Electronic File Name: Document(s) to which this term applies:

Committees affected by this term:

Office Use IPC Office Date Received: Comments Collated: Returned for Action: Revision Inclusion:

Committee 2-30 Date of Initial Review: Comment Resolution: Committee Action: ❑ Accepted ❑ Rejected ❑ Accept Modify IEC Classification

Classification Code • Serial Number Terms and Definition Committee Final Approval Authorization: Committee 2-30 has approved the above term for release in the next revision. Name:

Committee:

IPC 2-30

Date:

Related IPC Documents and Videos Be sure your organization has the following: IPC-A-610C

Acceptability of Electronic Assemblies The industry’s most widely used acceptability document. IPC-A-610C illustrates industry-accepted workmanship criteria for electronic assemblies with over 600 full-color photographs and illustrations in a spiral bound format. Topics include component orientation and soldering criteria for through-hole, SMT and discrete wiring assemblies, mechanical assembly cleaning, marking, coating and laminate requirements. Buy it in hard copy or electronic format.

IPC/EIA J-STD-001C

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VT-56

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VT-58

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VT-59

Wire Preparation Video A visual introduction to wire preparation for wire harness manufacturing. Explains wire types, characteristics, AWG and insulation. Covers typical set up and operation for all types of applications. Defines parameters for cut and strip length and demonstrates insulation stripping. Reviews typical problems and provides evaluation guidelines.

Visit www.ipc.org/bookstore for pricing information and to place your order quickly and easily.

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ISBN: 1-580982-95-6

IPC-A-620

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