Research on the Method of Optimizing the Stress and Improving the Performance for MEMS Gyroscope Based on the Cantilever-Plate Structure.

Thermal stress is one of the most important factors damaging the temperature-dependent performance of MEMS gyroscopes. To reduce thermal stress and improve their performance, this paper deduced the production and effects of thermal stress on a high-precision MEMS butterfly gyroscope theoretically, which provided a basis for optimization and experiments. A novel cantilever plate structure was designed based on the working modes of the MEMS butterfly gyroscope and optimized based on our simulation to achieve stress isolation. The simulation results showed that after integrating the cantilever plate structure, the stress acting on the MEMS butterfly gyroscope was reduced by 346 times, while the average capacitance gap error was also reduced by 36 times within the same variable temperature range. In addition, the cantilever plate structure was fabricated and integrated with the MEMS butterfly gyroscope. Experiments were also conducted to demonstrate the effect of reducing the thermal stress, and the results showed that the frequency variation was reduced by 28.6% and the bias stability increased by about 2 times over the full temperature range after integrating the cantilever plate structure into the gyroscope. This demonstrated that the cantilever plate structure can effectively reduce thermal stress and improve the performance of the MEMS butterfly gyroscope.