Study on Packaging Thermal Stress of Micromechanical Silicon Resonant Accelerometer

Abstract

Packaging thermal stress is harmful to the performance of the micromechanical silicon resonant accelerometer. In order to decrease the packaging thermal stress, correlations of packaging thermal stress with the material properties, curing temperature and geometrical size of adhesive layers of adhesive materials were discussed. A finite element model of package was developed to analyze the influence of surface mounting technology (SMT） on the micromechanical silicon resonant accelerometer. The simulation results show that the Young’s modulus, thermal expansion coefficient, curing temperature and geometrical sizes of adhesive layers are important influencing factors for packaging thermal stress and the warpage of the chip. The thermal stresses during the process of SMT will cause the resonant frequency shift.