Research on the Temperature-dependent Performance Improvement of Butterfly Gyroscope with Stress Isolation

Abstract

The temperature-dependent performance of the x/y-axis MEMS gyroscopes still becomes a limit for high precision. This paper theoretically analyzed the zero offset output and scale factor of the butterfly gyroscope influenced by thermal stress and the hysteresis of strain. And the stress isolated structure was designed to integrate with the gyroscope for relieving the thermal stress. The pre-buried etched mask process was proposed for its fabrication. Tested in variable-temperature environment, the zero offset output difference between heating and cooling process of optimized butterfly gyroscope was declined from 0.08°/s to 0.01°/s. Moreover, the zero-bias stability and instability after compensation were also improved from 32.16°/h to 8.67°/h and 3.04°/h to 0.78°/h respectively, which demonstrate the effectiveness of optimization design. At the same time, the reported temperature-dependent performance reached a high level in the x/y-axis MEMS gyroscopes.