Know About Wire Harness Components From the IPC A620 Digital Standard
HomeHome > News > Know About Wire Harness Components From the IPC A620 Digital Standard

Know About Wire Harness Components From the IPC A620 Digital Standard

Apr 02, 2023

A wire harness assembly creates a systematic electronic or electrical wiring system intended to transport information, sensor signals, and electrical power, which groups wires, cables, connections, and other components together. Such assemblies connect electrical and electronic components that generate power and convey signals for any given system to work, from laptops to cars. Therefore, any equipment must have a wire harness assembly to be powered accordingly.

You must purchase IPC A620 digital standard as it is the sole industry-accepted standard for the requirements and acceptance of cable and wire harness assemblies. The IPC 620 states the accepted standards and compliance, rules, and various industrial norms that will help you to know about cable assembly and wire harness assembly 101.

The standard outlines requirements for

Wire prep



Crimping of stamped

Machined Contacts

Formed contacts

Insulation displacement connectors


Ultrasonic welding







Coax/biax cables

Wire-wrap terminations



Wire Harness vs. Cable Assembly

The main distinction between wire harness assembly and cable assembly is as follows. Wire harness assemblies connect many points or circuits with several breakouts traveling in different directions, as opposed to cable assemblies, which are made to provide a passage from one point or circuit to another. The wire harness has other terminations for each breakout to accommodate its various functions. Once put together, wire harnesses typically include several branches that run in an equal number of directions, each having the necessary terminals at the end.

Components Of Wire Harnesses

In today's wiring systems, wire harness assemblies comprise dozens of wires and numerous components, and terminations are not unusual. Each element can impact the effectiveness of a wire harness. Therefore, picking the correct parts for the wire harness to match its application requirements is crucial when the design phase is complete. Is it for a stifling workplace or a spotless interior office space? Will it be outside in the weather? Is it exposed to harsh temperatures, chemicals, or fumes? Will it flex, or will it stay in place?

The application determines the best wire to use, including the number and kind of conductors, the sort of conductive material, the components’ plating, and the conductors’ stranding. The answers to these questions will influence the choice of the appropriate components. The most adaptable conductor material, for instance, is copper. Copper is compatible with different coatings that improve its corrosion resistance, even though it cannot be utilized alone due to its low corrosion resistance.

Moisture and Corrosion

Conductors can operate in even the most difficult situations with the help of plating, which can offer essential corrosion protection. The plating will help to increase the application's conductivity if corrosion is a problem. Tin is preferred in applications where moisture is a major concern because it resists corrosion, is inexpensive, and helps with termination. Coatings like silver or nickel allow conductors to function dependably up to 200°C and 260°C, respectively, for extreme temperature wire harness applications.

Conductive Substance

It's crucial to pick the proper conductive substance. The conductivity needs of the application will dictate whether a single thick strand of material or numerous thin strands of substance should be chosen. Use higher quantities of more delicate strands when flexibility is required. The conductor's measurements will be based on how much current it will carry if the conductor is intended to supply power. Wherever a signal must be sent, the length and speed will decide the conductor material.

Sheathing and Insulation

The application's requirements will also define the best material to use for sheathing and insulation of the wire harness assembly. Materials can be made of thermoplastic or thermoset compositions and can be made to conform to various environmental conditions or come in multiple colors to aid in identification. The correct material for insulating the wire harness assembly must consider the operating temperature, the harshness of the environment, exposure to chemicals and fluids, and the voltage or current considerations the assembly will carry. For instance, a hefty, tough sheath would be necessary for high-temperature uses that require a dynamic condition of constant movement to work as intended.

EMI Shielding

Additionally, insulation can be used to block EMI from outside sources. Twisting pairs of cable or wires further decreases EMI in assemblies for data transmission and communication. To increase flexibility and create a more aesthetically beautiful harness, conductors or twisted pairs of cable can be wrapped together using cabling. When shielding is done correctly, EMI or any radio frequency interference (RFI), if any, can be further controlled. There are various choices, including spiral, foil, and braided shields. Both the high or low-frequency requirement and flex life will affect the shielding choice. The most effective and flexible interference protection across all frequencies is provided by a foil as well as a braided shielding combination, which is also the priciest choice.

The material for the outer sheath or the harness's protective jacket must withstand the environment's physical demands, maintain its flexibility, and be flame-resistant. The more popular and reliable jacket for harnesses is PVC, a polymeric substance.


The signal's kind and speed will influence the connections chosen for a wire harness assembly. The terminal options will depend on the type of connector. The two main choices are crimp-type connectors or soldered or welded connections.

Last but not least, make sure the wiring harness assembly is suitably attired before installation. Wires entering and leaving the bundle should be tidy and attractive, with terminal strain relief. Wires in the assembly should always be handled carefully and should never be overbent. Add a servicing loop beyond the termination point to prevent or reduce strain, which can happen during breakouts, mounting, or when wires expand or contract during temperature swings, as well as to allow such flexibility.

Finding the proper wire harness assemblies for today's wiring systems can be difficult. The correct components must be chosen for a wire harness after the design specifications have been accepted for the application in order to guarantee its integrity, functioning, and lifespan, with little routine maintenance needed.