REDUCTION OF OUTGASSING FROM SILVER ALLOY CONTACTS SURFACE BY AU ELECTROPLATED LAYER FOR USE IN HERMETIC RELAYS

The gold electroplated surface layer of silver alloy (Ag with 0.1 wt% Mg) appears to play an important role for hermetic relays, simultaneou sly decreasing contact resistance with increasing lifetime. The thickn ess of the gold layer is approximately 0.5 mu m. The annealing at 135 degrees C and 200 degrees C provides a surface of extremely low outgas sing at contact operation. The surface of the gold layer is investigat ed by Auger Electron Spectroscopy (AES) and the outgassed products by mass spectroscopy in a high vacuum experimental system. The gold elect roplating and subsequent annealing improve the desorption of the surfa ce at low outgassing rate.