Qualification of Connectors Manufactured with Diffused Gold R156 Inlay Contacts

A qualification test has been performed to determine the long-term reliability of two inlay materials used in contacts for printed circuit board (PCB) connect0rs. The contacts were fabricated from diffused gold R156 (DGR156) and Western Electric No. 1 Metal (# 1) inlay materials.. The qualification of the DGR156 inlay materials is especially important, since implementation of this material system results in a considerable cost reduction for this family of PCB con~ nectors. The performance of the two inlay materials was compared against a hard gold electroplated finish. The contact was tested in a mated condition against gold-p!ated 0.025-in square coined backplane :pins. Test samples were subjected to two wear levels of 50 and 200 insertion/withdrawal cycles. Different sets of test contacts were then submitted to a wear evaluation, mechanical vibration test, andthe following accelerated aging tests: high humidity with temperature cycling, thermalaging, temperature cyel!ng, and two BTL corrosion gas tests. Theresults of the wear evaluation, mechanical tests, and accelerated aging tests show satisfactory performanc9 for the contact system. Thus we have recommended that DGR156 inlay material be substituted for the Co hardened Au finish used inthe PCB family of connector codes. This will result in considerable cost savings without significant decrease in reliability