Reliability of gold wire leads for MEMS gyroscopes under a thermo-mechanical coupling field

In this study, we investigate the vibration characteristics and failure modes of gold wire leads in MEMS gyroscopes under high-temperature and thermal-shock conditions through simulation and experimental analysis. The simulation results indicate a gradual degradation in the intrinsic frequencies of the leads as the temperature rises from -40 °C to 120 °C. The simulation results are verified by testing the intrinsic frequency with a percentage error of less than 2%. The average temperature drift of the intrinsic frequency is approximately - 8.82 Hz/°C. When comparing the intrinsic frequency changes before and after burn-in and thermal-shock tests, it is evident that the mechanical degradation of the gold wire leads is limited under the severe thermo-mechanical coupling field, with frequency fluctuations ranging from 0.01% to 17%. There is no occurrence of a lead fracture or solder joint failure. The main failure modes are lead collapse and short-circuit failure due to the fatigue of long leads. Minimizing the span and height of the leads can reduce the risk of fatigue and short-circuit failures.