Piezoelectric acceleration sensor and method of detecting acceleration and manufacturing method thereof

摘要

An acceleration sensor 201 comprises a longitudinal effect type detection unit 203 and a lateral effect type detection unit 204. The longitudinal effect type detection unit 203 comprises a longitudinal effect type piezoelectric element 211 comprising a piezoelectric body 211a of a thin film, an electrode 211b and an electrode 211c, which is formed on a deposition substrate 221 serving also as a weight. The lateral effect type detection unit 204 is constituted by providing a lateral effect type piezoelectric element 213 comprising a piezoelectric body 213a of a thin film, an electrode 213b and an electrode 213c, which is formed on the deposition substrate 221 and is cantilevered above a groovy recessed part 105a on a substrate 105. A detection circuit 116 detects an acceleration in a predetermined direction, based on an output of both the longitudinal effect type detection unit 203 and the lateral effect type detection unit 204. Consequently, it is possible to detect an acceleration in a predetermined direction and to make a wider dynamic range and a wider band.