Packaging effects on the performances of MEMS for high-G accelerometer with double-cantilevers

摘要

In this work, finite element simulation has been applied in frequency-domain and time-domain analyses for a packaged accelerometer used in high-G environments. In order to understand the effect of the adhesive material, which is filled in the gap between the sensor chip and the package bulk, on the output signal of accelerometer, a simplified packaged structure has been adopted in this analysis. The results from simulations show that the Young's moduli of seal adhesive has important influences on the mode shapes of the packaged accelerometer and a small Young's modulus will bring in strong distortion of output signal of accelerometer. As the Young's moduli increased, the waveform of accelerometer output signal became better after digital filtering. The seal adhesive with Young's modulus like molding compound in IC packaging would not induce significant problems in signal distortion. The frequency and averaged amplitude of output signal of the packaged accelerometer were not affected by Young's modulus of seal material. The accelerometer output was linearly dependent on the input of acceleration impulse and the response was very well when the input of the acceleration amplitudes changed. The simulations for a practical packaging structure defined in this work showed that the results were similar to the simulations for the simplified structure of accelerometer with packaging, and the simulation results from the simplified structure could serve as a basis for design of high-G accelerometer packaging in a certain degree. (C) 2003 Published by Elsevier Science B.V. [References: 8]