Application of selective anodic bonding technology in grating gyroscope

Anode bonding technology is widely used in wafer-level MEMS device manufacturing and packaging. For devices with cantilever beam structure, it is easy to attract during bonding. Selective anode bonding technology is used to prevent the gyro from attracting failure during bonding. The formula of electrostatic pull-in voltage between gyro beam and glass was educed, and the relationship model between pull-in voltage and silicon structure glass gap was established. First, the gyroscope structure was made by DRIE, then the grating was made by sputtering Al/Cr on the glass substrate, and finally the anodic bonding was performed. The results showed that the bonding interface has no defects, and the conductivity of Cr and its oxides made the silicon-glass anodic bonding without electrostatic attraction. The average bonding strength was 33.94 MPa, and the bonding quality was good.