Patent ID: 6892579

Claim:
An acceleration sensor comprising an acceleration sensor element which comprises: a mass portion located in a center of the acceleration sensor element; top plate of the mass portion fixed on an upper end of the mass portion; a rectangular thick support frame surrounding and being at a distance from the mass portion; a top plate of the frame fixed on an upper end of the frame; four elastic support arms bridging the mass portion top plate and the frame top plate and hanging the mass portion in a center of the frame; and strain gauges formed on the elastic support arms; the mass portion top plate having a portion bonded to the mass portion upper end and a portion protruding toward each of the elastic support arms from the bonded portion of the mass portion top plate, so that a cross section of the mass portion top plate on a boundary between the bonded portion and the protruding portion is larger than a cross section connecting the protruding portion to the elastic support arm; and the frame top plate having a portion bonded to the frame upper end and a portion protruding toward each of the elastic support arms from the bonded portion of the frame top plate, so that a cross section of the frame top plate on a boundary between the bonded portion and the protruding portion is larger than a cross section connecting the protruding portion to the elastic support arm.