SEMICONDUCTOR ACCELERATION SENSOR

摘要

There is provided a semiconductor acceleration sensor capable of detecting accelerations in two direction parallel to a surface of a diaphragm and orthogonally intersecting each other with appropriate sensitivity. The semiconductor acceleration sensor (10) includes diaphragm pieces (13a to 13d) extending from the center of the surface of the diaphragm along X-axis and Y-axis orthogonally intersecting each other to the wafer outer frame portion (12a). Piezoresistors (Rx1 to Rx4, Ry1 to Ry4, Rz1 to Rz4) are formed thereon. In the diaphragm piece (13a) and the diaphragm piece (13b) arranged on a straight line along the X-axis and the diaphragm piece (13c) and the diaphragm piece (13d) arranged on a straight line along the Y-axis, the areas of the cross section orthogonal to the axes are respectively set in accordance with the maximum value of the acceleration in the X-axis direction or the Y-axis direction.