An Evaluation of Palladium and Palladium-Silver Alloy in a Dual-in-Line Package Switch

Palladium and R-156 alloy (60%Pd-40%Ag) were evaluated as potential substitutes for the gold contacts in a dual-in-line package (DIP) switch. The DIP switch was of the rocker type employing a spring loaded spherical gold electroplated ball as the movable contact. Prototype switches employing stationary contacts punched and formed from selectively striped inlay material of palladium or R-156 alloy were constructed. Switches were evaluated for the following: 1) thickness and hardness, 2) formability and adhesion, 3) porosity before and after 2000 cycles, 4) wearability, 5) contact resistance before and after 2000 cycles. The test data indicated that gold to palladium or gold to R-156 contact systems will provide stable contact resistance with acceptable wear properties over the life of the switch.