SEMICONDUCTOR ACCELERATION SENSOR AND VEHICLE CONTROL SYSTEM USING SAME

摘要

PURPOSE:To eliminate a defect in the operation of a sensor due to melt-sticking by covering at least part of the surface of a conductive inertia body or/and conductive surfaces provided on an upper and a lower insulating substrate facing the inertia body, with an electric insulating material. CONSTITUTION:Laminate structure is formed of a semiconductor silicon plate 1 and two insulating plates 2 and 3 and a cantilever 4 and the inertial body 5 are formed on the plate 1. Electric insulating layers 6 and 7 are formed entirely on the top and reverse surfaces of the inertial body 5 and coupled with the main body of the plate 1 by a lever 4 which is thinner than the inertia body 5. Then when acceleration is applied in the up-down direction of the sensor, an inertial force operates on the inertia body 5 and the lever 4 deflects to displace the inertia body 5 in the opposite direction from the acceleration operating on the sensor. Consequently, the gaps between the inertia body 5 and electrodes 8 and 9 provided to the insulating plates 2 and 3 vary in size, so that capacitors formed of the two upper and lower electrodes 8 and 9 and inertial body 5 vary in electrostatic capacity. The electrostatic capacity type acceleration sensor detects the acceleration by an acceleration detecting circuit 10 from the acceleration dependency of the electrostatic capacity.