Capacitance type acceleration sensor

摘要

The capacitance type acceleration sensor disclosed is one in which a variation in a distance between first and second electrodes caused by acceleration is measured as an electrostatic capacity variation. The acceleration sensor includes a fixed electrode, a movable electrode and a reference electrode. The fixed electrode constitutes the first electrode or the second electrode, and a movable electrode constitutes the other of the first or second electrodes. The reference electrode is such that its distance with respect to the first and second electrodes is not caused to be changed by acceleration. The fixed electrode and the movable electrode are disposed in an overlapping position in a direction in which the acceleration is detected. Thus, it is possible to scale down the sensor chip area by the magnitude of the area of the reference electrode.