Patent ID: 8664029

Claim:
A process for fabricating a capacitance type tri-axial accelerometer comprising: preparing a wafer haying an upper layer, an intermediate layer and a lower layer, said upper and lower layers being made of semiconductor material and said intermediate layer being made of insulating material; etching said lower layer of said wafer to form an isolated proof mass having a core and four segments extending from said core; etching said upper layer of said wafer to form a suspension and four separating plates, said suspension connecting with said core of said proof mass through said intermediate layer; etching away a portion of said intermediate layer located between said four segments of said proof mass and said plates of said upper layer such that said proof mass can freely swing up and down following said suspension; and disposing an electrical conducting means to pass through said intermediate layer from said suspension to said core of said proof mass such that said suspension and said proof mass are electrically connected.