微加速度计摆片质量的测量方法研究

STUDY ON ESTIMATION OF THE PROOF MASS OF A MEMS ACCELEROMETER

梳齿式微机械加速度计摆片的质量是影响其性能的重要机械参数,获得实测值十分必要。提出一种基于开环频率响应试验和静态静电力试验求取摆片质量的方法,由加速度计的开环传递函数及摆片的力平衡方程,得到包含摆片质量的方程组,通过求解该方程组得出摆片的实际质量。对具体加速度计的试验结果表明,该方法能准确地估算摆片的实际质量,并能在制造现场使用,不需要特殊的测量环境和仪器设备,是一种简便而有效的试验方法。

The proof mass of a comb-finger MEMS acceler-ometer is an important mechanical parameter, which will affect the performance of the accelerometer greatly, so it is necessary to acquire the actual value of the proof mass. A method based on the open-loop frequency response experiment and the static electrostatic force experiment is investigated for this purpose. The equation set which contains the variable of the proof mass can be derived from the open-loop transfer function and the equation of the force balance. Then the actual value of the proof mass can be resolved from the equation set. The experimental results show that the actual value of the proof mass can be estimated with a high accuracy by this method. It is also a convenient and useful method to be used in the fieldwork without the special requirement of environment and costly facilities.