基于梳齿间距偏差的硅微加速度计冲击与阶跃信号响应模型

Pulse and Step Signal Response Models of Micro-Accelerometers Based on the Comb Gaps Deviation

源于概率统计理论,针对梳齿电容的微细加工偏差,给出了当各梳齿间距偏差在一定范围内独立且均匀分布时,单边电容和双边电容驱动的硅微加速度计冲击与阶跃信号响应物理模型.经过有限元仿真和Monte Carlo模拟验证,结果表明理论模型与仿真值之差小于10%.模型指出,当梳齿间距偏差由0变化到20%,加速度计在受到冲击与阶跃加速度信号作用时,其可靠工作范围将比无偏差理想情况下降10%~15%.该模型可望应用于实际有加工偏差的微加速度计可靠工作范围预先评估与设计.

Based on probability and statistical theory,pulse and step acceleration signal response models of capacitive micro-acceler- ometer with single-sided driving mode and double-sided driving mode are investigated,respectively,which are established on the assumption that the comb gaps conform to the uniform distribution within a given scope induced by the MEMS processing non-ideality. The precision of the models has been verified by the FEA and monte carlo methods with ANSYS software. The deviation between them is less than 10%. The models suggest that the reliable operation ranges of the accelerometers will decrease 10% -15% when the comb gaps deviate 0-20% from the ideal value. The models can be used in the estimation of the reliable operation ranges of capacitive accelerometers.