低热机械噪声MEMS加速度计设计

Design of low thermal-mechanical noise MEMS accelerometer

介绍了一种能够在大气条件下具备低噪声、高灵敏度特性的MEMS加速度计设计、制作与测试。器件采用梳齿电容检测方法,利用MEMS体硅加工工艺,实现了210对梳齿的加速度计制作。该加速度计不需要真空封装和阻尼孔就能实现低热机械噪声特性,其理论热机械噪声为0.018μg/槡Hz。加速度计芯片在大气封装和无阻尼孔情况下Q值高达455.06,与理论分析结果相符,具有较低的热机械噪声。

The design, manufacture and test results of a MEMS accelerometer with low thermal-mechanical noise and high sensitivity is presented. This acceleration sensor is based on comb finger capacitance testing and realized by bulk silicon process. There are 210 pairs of comb finger in the acceleration sensor. This sensor does not need vacuum package to achieve low thermal-mechanical noise. The theoretic value of thermal-mechanical noise is 0. 018 μg/Hz. The test result shows that the Q factor achieves 455.06 in atmosphere package and without damping holes, which matches the analysis result in theory.