Effects of adhesive on silicon microgyroscopes

The silicon microgyroscopes are very sensitive to the residual stresses, which degrade the microgyroscopes performance. This study used finite element analysis to simulate the residual stresses induced during the packaging process. The silicon microgyroscope is fabricated with SOG (Silicon-on-Glass) technology and packaged with ceramic packages. FEM simulation based on a simplified structure of the packaged gyroscope was applied in static analyses in order to find out the affections of adhesive on the thermal stresses during the packaging process. The simulation results show that the Young's modulus of adhesive has influence on thermal stresses. When the height of the adhesive layer is above 60 microns and the plane dimension of adhesive layer is larger than that of microgyroscope chip, the stress is small.