Patent ID: 7464591

Claim:
A semiconductor acceleration sensor having a fixed part and a weight part connected to the fixed part by an elongated pair of beam parts having bending properties so as to electrically detect a movement of the weight part when an acceleration is applied thereto, wherein: the beam parts are formed having a L-shape, each of the beam parts having proximal ends at two opposite corner sides of the weight part and extending along two sides of the weight part adjacent thereto so as to allow a vertical movement of the weight part when an acceleration in a vertical direction is applied to the sensor; there are provided a protruding portion protruding from the fixed part toward the weight part, and a receiving recessed portion which receives the protruding portion protruding from the weight part toward the fixed part to surround the protruding portion, at a location close to the proximal end of each of the beam parts and in a space between the weight part and the fixed part; and the protruding portion contacts an inner wall surface of the receiving recessed portion so as to limit horizontal movement of the weight part, when an acceleration in a horizontal direction is applied to the sensor.