Acceleration Sensor

摘要

An acceleration sensor includes a weight portion having a recess section and a solid section, beam portions, a movable electrode provided on the opposite surface of the weight portion from an open surface of the recess section to extend over the recess section and the solid section, a first fixed electrode arranged at the opposite side of the movable electrode from the recess section, and a second fixed electrode arranged at the opposite side of the movable electrode from the solid section. The acceleration sensor detects acceleration using a change in capacitance between the movable electrode and the fixed electrodes caused by rotation of the weight portion. The beam portions are shifted toward the recess section such that an angle between a perpendicular line extending from a gravity center position of the weight portion to the rotation axis and a surface of the movable electrode becomes equal to 45 degrees.

主权项

1. An acceleration sensor, comprising:
a sensor chip including a first weight portion and a second weight portion, a plurality of beam portions aligned along a straight line and configured to support the first weight portion and the second weight portion, the plurality of beam portions portion including a first beam portion and a second beam portion, a frame portion surrounding the first weight portion and the second weight portion, and electrode portions disposed between the first weight portion and the second weight portion, the electrode portions including a first electrode portion, a second electrode portion and a third electrode portion, wherein one end of the first beam portion is connected to the first electrode portion and another end of the first beam portion is connected to the first mass portion, wherein one end of the second beam portion is connected to the first electrode portion and another end of the second beam portion is connected to the second mass portion, and wherein the second electrode portion is disposed on one side of the straight line and the third electrode portion is disposed on another side of the straight line.