A study on MEMS acoustic vibration sensor technology

By using ANASYS finite element analysis software to analyze the first three order resonance frequencies and strain values of the porous and porous free structure of the acoustic sensing chips, the optimization of the structure indicates: the resonance frequency of the porous structure varies lower relatively, but the stress improves relatively higher, we utilize beam membrane structure, the featured size of the beam thickness is 50 um. We utilize MEMS technology to fabricate acoustic vibration sensor chips on single crystalline silicon, and use second order vibration mode test unit to measure vibration signal, on condition of 5v power supply, the sensitivity of chip is about 26.8mV/g, resonance frequency is 5.19kHz, frequency response range is over 20∼2000Hz, the frequency at the point of 3dB is 2.93kHz.