A Resonating Comb/Ring Angular Rate Sensor Vacuum Packaged Via Wafer Bonding

The best features of a comb and ring device have been combined to provide an improved micromachined angular rate sensor. The use of differential combs attached to a centrally supported ring gives this electroformed surface micromachine improved signal output and temperature performance. Previous results have been reported for vibratory ring sensors vacuum packaged in solder sealed CERDIPs. Bulk silicon etching and wafer to wafer bonding, used to fabricate millions of pressure sensors and accelerometers each year, have been employed to vacuum package this new CMOS integrated micromachine. Wafer level packaging allows for MEMS chip-scale packaging at the board level. The goal of this project is to develop a low cost sensor capable of reliably functioning at temperatures between -40 °C and 85 °C. The design, modeling, process, package, performance and automotive applications of this sensor will be covered.