Empfasis - IPC WHMA-A-620

A publication of the National Electronics Manufacturing Center of Excellence

February 2004

EMPF Director
Michael D. Frederickson
mfrederickson@aciusa.org

IPC/WHMA-A-620, Requirements and Acceptance for Cable and Wire Harness Assemblies, describes the acceptability criteria for producing crimped, mechanically secured or soldered interconnections as well as the lacing and restraining criteria related to cable and harness assemblies. IPC/WHMA-A-620 was jointly developed by the IPC and WHMA (Wire Harness Manufacturer's Association) along with 86 additional user and supplier companies.

In addition to providing Industry with this new specification, IPC/WHMA has developed the Operator Proficiency Training Program to accompany the specification. The course is designed to enable operators to recognize the difference between an acceptable and unacceptable assembly. The ability to properly identify acceptable assemblies will help dramatically reduce the amount of rework required during manufacturing. In an effort to meet and exceed customer and quality system requirements, electronics manufacturers are relying more on standardized training for their workforce. Assembly operators, technicians, and engineers are ideal candidates for this course. The knowledge they gain in just a few days can be immediately applied to many process issues related to cable and wire harness assemblies.

The Operator Proficiency course is designed modularly in order to accommodate the wide variety of cable and wire harness assemblies currently being used in industry. There are eighteen modules and manufacturers can select the ones they need to meet their needs. Proficiency in understanding the specification is determined
through a series of written standardized exams developed by the IPC/WHMA. Operators will be tested on each module in which they are trained. Operators who demonstrate proficiency will receive a portable certification in the areas where proficiency is demonstrated. Certifications are valid for 2 years. A brief description of each module follows.

Modules 1 and 2 (prerequisites for modules 3-18): covers the purpose and scope of the document, general criteria, and related applicable industry specifications. Students will learn how to properly interpret the acceptability requirements, understand the difference between the classes of electronics, and become familiar with commonly used terminology. Companies can select additional training to the various other cable and wire assembly acceptance requirements.

Module 3-Preparations: Covers the allowable amount of conductor strand damage, wire separation, and insulation damage.

Module 4-Solder Terminations: Covers the requirements for tinning and gold removal of wires, cleanliness, insulation, flexible sleeve insulation, wire separation, wire attachment and solder requirements for wires attached to commonly used terminals.

Module 5-Crimp Terminations: Covers the requirements and allowable deformation for stamped/formed contacts and machined crimp contacts.

Module 6-Insulation Displacement Connections (IDC): Covers the acceptance criteria for mass termination, flat cable and discreet wire terminations.

Module 7-Ultrasonic Welding: Covers the insulation clearance and weld nugget criteria.

Module 8-Splices: Covers soldered splices, crimped splices and ultrasonic welded splices.

Module 9-Connectorization: Covers acceptance criteria for hardware mounting, strain relief, sleeving, boots and allowable amount of connector damage.

Module 10-Molding Potting: Covers the requirements for molding and potting of cables and wires.

Module 11-Cable Assembly and Wires: Covers the identification of reference designators and surfaces and how to properly measure wire lengths.

Module 12-Marking and Legibility: Covers the requirements for marking content, legibility, permanency, location, functionality, and marker sleeves.

Module 13-Coaxial and Twinaxial Assemblies: Covers the requirements for stripping, center conductor terminations, solder ferrule pins, coaxial connectors, terminal covers, shield terminations, center pin position, semi-rigid coax, swage-type connector, and soldering and stripping of biaxial or twin axial wires.

Module 14-Wire Bundle Securing: Covers the proper tie wrap and lacing application, requirements for wire breakouts, and wire bundles.

Module 15-Shielding: Covers the requirements for electrical shielding. Operators will learn requirements for braided shielding, shield termination, proper tape wrapping, conduit shielding, conductive coating, and shrink tubing.

Module 16-Cable and Wire Harness Protective Coverings: Covers protective coverings used for cable and wire harness assemblies. Subjects include braid, taping, sleeving and spiral plastic wrap.

Module 17-Installation: Covers the requirements for installation of hardware and wire harness installation. Operators will learn the proper assembly sequence for hardware and the stress relief required for wires.

Module 18-Solderless Wrap: Covers the acceptance requirements for solderless wrap connections. Topics include number of turns, turn spacing, end tails, insulation wrap, raised turns, connection position, wire dress, wire slack, plating and damage.

At the request of industry, the EMPF is now offering Operator Proficiency training to this latest industry consensus specification. Interested parties should call the EMLC Registrar for more information at (610) 362-1295 or send email to registrar@empf.org.

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