Effect of residual stress on modes of coupled MEMS resonator array

The residual stress introduced in the packaging process of the MEMS device will cause the drift of the eigenfrequencies, thereby affecting the function of the device. In this paper, the influence of residual stress on the modal characteristics of MEMS resonator array is analyzed by laser Doppler method, and the local vibration of coupling beam with 432nm amplitude is measured by stroboscopic method. The finite element analysis model including residual stress is established. The results show that the effect of residual stress on the eigenfrequencies of different modes of the resonator differs by 14.47 times, and the in-plane mode eigenfrequency of one of the resonators increases by 170.5%. The in-plane vibration test shows that the in-plane mode of the resonator is coupled with the local mode of the coupling folded beam.