Prediction of Electrical Contact Resistance of Tin-Plated and Silver-Plated Terminals

Automotive wiring harness helps the interaction between electrical equipment such as in-vehicle controllers, sensors, actuators, and lamps. An automotive connector, on the other hand, is one of the important parts, which connects wiring harness to other harnesses or electrical devices. Automotive connector terminals are generally made of tin, gold and silver plated copper alloys. Figure 1 shows an example of a sectional drawing of the terminals in engagement status. The female terminal has a spring made of copper alloy. An electric current can flow between the male and female terminals because these terminals have a mechanical contact caused by the force of the spring. For the design of new connectors, the terminal resistance must be known before starting the trial-production of the terminals. For this reason, it is important to predict electric contact resistance influenced by terminal design factor such as contact force, contact shape, plating material and plating thickness.