Tri-axial MEMS accelerometer

US9829504B2 · kind B2 · utility

Assignee

• Chinese Academy of Sciences, Institute of Geology and Geophysics · CN

Inventors

• Chen Sun · Beijing, CN
• Lian Yu · Beijing, CN

Key dates

• Filing date: May 6, 2014
• Grant date: Nov 28, 2017
• Expiry date: Aug 29, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31053
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A tri-axial MEMS accelerometer includes a top cap silicon wafer and a bottom cap silicon wafer coupled with a measurement mass. The measurement mass has a two level structure, each level having an inner frame coupled to an outer frame by a plurality of first elastic beams, a mass coupled to the inner frame by a plurality of second elastic beams, and a comb coupling structure between the mass and the inner frame. The comb coupling structures are arranged in an orthogonal orientation. The top level and bottom level measurement masses measure acceleration in perpendicular directions. The top level and bottom level measurement masses and the inner frame form an integral unit which moves along a third direction. Acceleration in the third direction is measured from the change in capacitance between the integral unit and the top cap silicon wafer and bottom cap silicon wafer.