Fig. 4: Contact resistance characteristics of passivated silver plated spring pins on PCB with chemical nickel gold plating during temperature cycling.

• 温度循环试验后，光学观察显示PCB的化学镍金层整体有平滑的烙印，但化学镀金层完好无损。弹簧引线镀银层同样也没有受磨损。