Robust Z-axis accelerometer

摘要

To provide a Z-axis acceleration meter which compensates for an offset error from bending of a wafer.SOLUTION: The present invention includes a first proof mass 411, a second proof mass 412, a third proof mass 413, and a fourth proof mass 414. The proof masses 411, 412, 413, and 414 are formed as seesaws which receive a rotation to the outside of an xy flat surface in response to a z-axis acceleration. The proof masses 411, 412, 413, and 414 are suspended from the same center anchor point by distortion-flexible lateral suspension parts 421, 422, 423, and 424. Errors caused by an output signal by bending of the wafer can be automatically compensated for by a differential capacity measurement.SELECTED DRAWING: Figure 4a