Patent ID: 7122396

Claim:
A semiconductor acceleration sensor comprising: a semiconductor sensor body including a weight fixing portion located at a central area thereof, a cylindrical support portion located at an outer peripheral area thereof, and a diaphragm portion having flexibility and located between said weight fixing portion and said support portion, an acceleration sensor element composed of diffused resistors formed in said diaphragm portion, and a weight fixed on said weight fixing portion in such a manner that a center of said weight is aligned with a centerline passing through a center of said weight fixing portion and extending in a direction orthogonal to an extending direction of said diaphragm portion, said support portion having an inner peripheral surface constituted by four trapezoidal inclined surfaces of a substantially identical shape that are annularly combined so as to define an outer peripheral surface of a frust-pyramidal internal space of said support portion, wherein said weight has an abutting portion including a linear portion which abuts against said inclined surfaces constituting said inner peripheral surface when said weight makes a maximum displacement in a direction where said diaphragm portion is located, wherein said abutting portion has a circular outline shape as seen from a side where said weight fixing portion is located, and wherein a stopper structure is constituted by said inner peripheral surface of said support portion and said abutting portion, for restricting a displacement range of said weight in a direction where said diaphragm portion is located.