Semiconductor dynamic quantity sensor

摘要

In a dynamic quantity sensor for detecting a dynamic quantity, a movable portion having comb-shaped movable electrodes is connected to a base portion through a beam portion as a spring portion, and moves in direction Y upon receiving dynamic quantity. Comb-shaped fixed electrodes are arranged opposite to the movable electrodes through detection intervals. A Q value of vibration of the movable portion in the direction Y is smaller than {fraction (1/500)} of a resonance frequency of the movable portion in the direction Y. Therefore, free vibration of the movable portion is rapidly damped so as not to adversely affect sensor output.