一种硅微机械结构振动幅度的电学测量方法及实验研究

Electrical Measurement Method and Experiment Study on Vibration Amplitude for a Silicon Micro-Structure

针对硅微机械结构振动幅度由于封装难以计算机视觉测量及电学测量中的精度受接口电路参数影响的问题,在对静电梳齿驱动、平板电容检测的硅微谐振结构进行建模分析后,提出基于单边带电压比的电学测量振动幅度的方法并分析了测量方法的原理。实验表明研制的某硅微机械谐振加速度计在受迫振动下的振动幅度为0.25μm,频谱分析还表明存在上电噪声引起的振动幅度,该测试方法还能应用于硅微谐振结构的谐振频率测量,同时为高品质因数的硅微机械谐振结构的可静电自激驱动提供了依据。

Drawback of computer aided vision measurement method presents because of the package of the silicon micromachined structure system, that the vibration amplitude accuracy of mechanical system is affected by the interface circuit parameters for electrical measurement. A model for silicon resonant structure with driving combs and sensing parallel plates is constructed and a new electrical measurement is also proposed based on single sideband ration. Experiment result show that the vibration amplitude is 0.25 p.m for a resonant micro accelerometer with 20 kHz AC driving voltage. Spectral analysis also showed the presence of vibration amplitude caused by electrical noise, this test method can also be applied to measure the resonant frequency for silicon micro structure.