Acceleration sensor

摘要

In an acceleration sensor, a sensor unit includes a weight portion having a recess section with one open surface and a solid section one-piece formed with the recess section, beam portions for rotatably supporting the weight portion such that the recess section and the solid section are arranged along a rotation direction, a movable electrode, fixed electrodes, detection electrodes electrically connected to the fixed electrodes to detect a capacitance between the movable electrode and the fixed electrodes. A fixed plate is arranged in a spaced-apart relationship with a surface of the weight portion on which the movable electrode is provided, and embedment electrodes are embedded in the fixed plate to extend along a thickness direction of the fixed plate, the embedment electrodes having one end portions facing the movable electrode to serve as the fixed electrodes and the other end portions configured to serve as the detection electrodes.

主权项

1. An acceleration sensor, comprising:
a sensor unit including a weight portion, a pair of beam portions configured to rotatably support the weight portion, a movable electrode provided on a surface of the weight portion, and a fixed electrode; a fixed plate arranged in a spaced-apart relationship with the surface of the weight portion on which the movable electrode is provided, the fixed electrode being arranged on one of two opposite surfaces of the fixed plate which faces the movable electrode; and an embedment electrode having end portions, the embedment electrode embedded in the fixed plate in a way such that the embedment electrode extends through the fixed plate along a thickness direction of the fixed plate so that one of the end portions is arranged on said one of the surfaces of the fixed plate and the other of the end portions is configured to serve as a detection electrode on the other of the surfaces of the fixed plate, wherein the fixed electrode is connected to said one of the end portions of the embedment electrode by an extension portion provided therebetween such that the embedment electrode is arranged out of alignment with the weight portion.