Patent ID: 6772632
Filing Date: 2004-08-10
Classification: B81B,G01P

Abstract:
An acceleration sensor comprising:a substrate layer having a displacing section provided at a central portion, a fixed section provided around said displacing section, and a connecting portion for connecting said displacing section to said fixed section so that said displacing section can displace; a weight disposed under said substrate layer, said weight including an upper surface peripheral portion that opposes a control surface formed on a lower surface of an inner part of said fixed section; a pedestal which is disposed so as to surround said weight and supports and fixes said fixed section from below; a weight joint layer which is interposed in a region other than said upper surface peripheral portion in a space between said weight and said substrate layer and is made of a material different from that of said weight and said substrate layer, and connects said weight to a lower surface of said displacing section; and a displacement detector for detecting a displacement of said displacing section; wherein when an acceleration is applied to said weight, said displacing section displaces with respect to said fixed section due to bending of said connecting portion, and a thickness of said weight joint layer is set so that said upper surface peripheral portion comes into contact with said control surface to control displacement when a degree of a predetermined directional component of an applied acceleration exceeds a predetermined tolerance.