Effect of switching rate on contact failure from contact resistance of micro relay under environment containing silicone vapor

Abstract

The undesirable effect of silicone vapor on contact resistance characteristics was examined by using micro relays. From the view-point of vapor transportation and deposition onto the contact surface, the thickness of adsorbed silicone vapor was clarified in conjunction with the formation of SiO/sub 2/. The growth of deposition of silicone molecules was proportional to the exposure time until monolayer formation. After this, growth of the film saturated regardless of the silicone vapor concentration. Furthermore, since molecules should be adsorbed on the contact surface during the breaking state of contacts, dependence of switching rate, operations per unit time, on the contact resistance characteristics was clarified. It was found that the number of operations to the contact failure was remarkably affected by the switching rate. Namely, adsorbed silicone increases with decrease in the switching rate. Therefore, as the switching rate increases, the number of operations until the failure caused by high contact resistance increases. However, after the monolayer formed, this number of operations until contact failure may be independent of the concentration and the switching rate.