Cables and wires have a major role when it comes to the manufacturing of different cable assemblies. Owing to this, its vital role ensures that the cable being used is up to standard. The wires have to meet the necessary requirements set aside by IPC-A-620. IPC-A-620 is an industry-consensus standard document for the requirements and acceptance of cable and wire harness assemblies. The IPC and Cable Harness Manufacturers Association developed the IPC/WHMA-A-620. The standard gives the necessary criteria required in wire prep, formed and stamped contacts crimping, terminals’ soldering, machined contacts, splicing, and molding. The standard also provides wrapping or lacing, marking, connectors, shielding, splicing, ultrasonic welding, wire-wrap terminations, and insulation displacement connectors.
IPC/WHMA-A-620 describes the materials, strategies, testing criteria, and acceptance methods applied in the production of crimped, soldered, and mechanically secured interconnections plus intertwined assembly practices linked with the cable and wire assemblies. IPC/WHMA-A-620 stands to be used as a document for product purchase. Nevertheless, it does not identify the end product or in-process frequency inspection.
Terms and Definitions
IPC-T50 provides specific terms that go in handy with their definitions. Such terms are used on the IPC-A-620 document with different definitions to describe particular requirements.
- Shall or Must- This means the requirement discussed in the document is “Mandatory” for every product class.
- Should- This depicts “recommendations” and can be applied to reflect on general industrial procedures and practices to provide guidance.
- Wire Diameter- This is denoted as “D.” It means the overall conductor’s diameter and insulation.
Classes of Products
A client is expected to identify the class to which the cable and wire assembly is examined. The acceptance or rejection decision needs to depend on applicable documentation. This includes specifications, contracts, standards, drawings as well as reference documents. IPC-A-620 provides a procedure that defines this standard comprising three product classes. These classes are;
- Class 1 (General Electronic Products)- The class comprises products significant for applications. The primary requirement includes the completed assembly function.
- Class 2 (Dedicated service Electronic Products)- This category contains products that require continuing performance and extended life, as well as products that require seamless services but are not necessarily vital. In most cases, failures are not caused by the end-user environment.
- Class 3 (High-Performance Electronic Products)- This class involves products that require performances required on-demand or continued performances are vital. Also, it includes where equipment downtime is not permitted or where the equipment should operate anytime needed, for example, a life support system and any other vital system(s), and lastly, where the end-use environment is likely to be hostile.
Specialized Designs
IPC-A-620 acting as an industry consensus standard document provides criteria for the technologies commonly applied. However, the document does not address the necessary combination of product design. Whenever there is an application of specialized or uncommon technologies, it is likely vital to have a specific acceptance criterion. When developing a specific criterion, there is an inclusion of customer consent and involvement. This means that the developed criteria will include an agreed definition for acceptance of all product characteristics. If possible, criteria, either new or old, on specialized products must be submitted using the Standard Improvement Form comprised in the standard.