Analysis of failure modes and mechanisms in thermally actuated micromachined relays for harsh environments space applications

This paper reports test results on electrical characteristics, evaluation of design, failure modes, and reliability of thermally actuated, commercially available micromachined relays. The selected parts have been characterized over a wide range of temperatures (from -100°C to +180°C) and varying load conditions (voltages from 10 V to 70 V, and currents from 5 mA to 200 mA). Mechanical integrity of the parts was evaluated by subjecting them to multiple mechanical shocks in the range from 100 G to 1000 G acceleration with up to 10,000 shocks. Operational life testing was performed at different contact voltages and current loads during 108 switching cycles. All components intended for space applications have to operate in vacuum conditions. To simulate space operation conditions, operational characteristics of the parts were monitored during vacuum testing. Typical failure modes associated with different test conditions are discussed in this paper.