Reduction of outgassing from silver alloy contacts surface by Au electroplated layer for use in hermetic relays

Abstract

The gold electroplated surface layer of silver alloy (Ag with 0.1 wt% Mg) appears to play an important role for hermetic relays, simultaneously decreasing contact resistance with increasing lifetime. The thickness of the gold layer is approximately 0.5 μm. The annealing at 135 °C and 200 °C provides a surface of extremely low outgassing at contact operation. The surface of the gold layer is investigated by Auger Electron Spectroscopy (AES) and the outgassed products by mass spectroscopy in a high vacuum experimental system. The gold electroplating and subsequent annealing improve the desorption of the surface at low outgassing rate.