Transition interface for improving the temperature characteristics of micromachined gyroscopes

Abstract

This paper reports a method for improving the temperature performance of micromachined gyroscopes by using a transition interface between the sensitive structure and the vacuumed package. We analyzed the effect of transition interface on the thermal stress of the micromachined gyroscopes. The temperature dependence of the static capacitance, resonant frequency and zero output were experimentally studied over the range ź40 to 60 °C. A micromachined gyroscope suspended by a slanted beam was adopted in the experiment. In order to identify how the factors affect the temperature performance of the micromachined gyroscope, two types of the introduced gyroscopes were characterized. One was the original gyroscope having no transition interface, and the other was using 2 mm silicon as the transition interface. In contrast to the original gyroscope having no transition interface, the static capacitance and resonant frequency of the gyroscope adopting transition interface had a smaller temperature coefficient, especially for the static capacitance which has more than an order of magnitude improvement. As a result, the bias instability of the gyroscope improved to a higher level over temperature variations. It would provide a convenient and practical method for improving the temperature performance of micromachined gyroscopes.