A silicon micromachined tuning fork gyroscope

Silicon micromachined vibrating gyroscopes with several proof mass sizes (600/spl times/600/spl times/360 mm/sup 3/, 1000/spl times/1000/spl times/360 mm/sup 3/, 2000/spl times/1000/spl times/360 mm/sup 3/) have been fabricated with the same technology including wafer scale packaging. The angular rate sensor is driven in lateral direction by electromagnetic force, and detects the perpendicular movements due to the Coriolis forces by means of four piezoresistors connected in a Wheatstone bridge configuration. First measurements showed excellent linearity with a maximum sensitivity of 4 nV/deg/sec with the largest mass. The last characterization deals with temperature dependence and excitation considerations.