The reliability investigation of gold plated electrical contacts under sliding conditions

The reliability of electronic systems is greatly depended on the reliability of electrical contacts inside. Gold plating is usually adopted as the top finish of the electrical contacts in dry circuits because of its excellent stability and conductibility. But driven by cost pressure, gold finish becomes thinner and thinner. It is even considered to coat gold plating only on one side of a pair of contacts. In this paper, the electrical contact performance of gold plated contacts was studied by sliding experiments. The failure mechanism was analyzed by the wear morphology and the element compositions in the wear tracks of gold plated contacts. Orthogonal experiments were used to study the influencing factors to cause sliding contact failure, including the coating states of gold finish on contact pairs (either on the probe or on the coupon), the thickness of gold plating, the normal force of the contact interfaces. The range analysis was carried out to show the significance of various influencing factors on contact failure during sliding. The life of the electrical contacts with gold plating on one contact side under sliding conditions was analyzed and discussed.