Electrical method to measure the dynamic behaviour and the quadrature error of a MEMS gyroscope sensor

The electronics on board of a vibrating MEMS sensor is able to compensate only for small changes in the mechanical characteristics of the device. Thus, it is of great importance to find an easy and fast way to evaluate the mechanical parameters, such as the resonance frequency and the damping coefficient, of a MEMS sensor before putting the device on the market [A. Cigada, E. Leo, M. Vanali, Optical and electrical methods to measure the dynamic behaviour of a MEMS gyroscope sensor, Proceedings of IMECE2005 ASME International Mechanical Engineering Congress and Exposition 2005, Orlando, Florida, USA [14]]. Moreover, for a vibrating MEMS gyroscope also the quadrature error, i.e. [Y.Y. Bao, C.L. Yung, Modelling and compensation of quadrature error for silicon MEMS microgyroscope], has to be kept below a given threshold in order to be able to acurately measure low angular speeds.Verification tests are usually carried out at the end of the production process, i.e. when the package is complete. Thus, only electrical measurements are possible. In the present paper, a reliable approach to determine mechanical parameters as well as the quadrature error of the MEMS device through electrical measurements is proposed and results are compared to more traditional optical measurements.