Capacitive micro-acceleration sensor with symmetrically combined elastic beam structure and production method thereof

Abstract

The invention relates to a capacitive micro-acceleration sensor with a symmetrically combined elastic beam structure and a production method thereof. The acceleration sensor comprises a symmetric center mass block, an external support frame, eight symmetric straight beams, two symmetric frame beams, a combined elastic beam structure, an upper cover plate and a lower cover plate, wherein the eight symmetric straight beams are used for connecting the center mass block with the external support frame, and the combined elastic beam structure is formed by connecting eight symmetric L-shaped beams together; and the other end of each straight elastic beam connected with the frame beams is connected to the middle or a vertex angle at the top end and the bottom end of the lateral face of the center mass block, and the other end of each L-shaped beam connected with the frame beams is connected to the inner side face of the external support frame. The acceleration sensor adopts the combined elastic beam structure which is formed by connecting the symmetric straight beams, the frame beams and the L-shaped beams together, has high symmetry and can remarkably reduce the cross-sensitivity of the sensor; and the sensor is produced by adopting a microelectronic mechanical system technology and is the capacitive micro-acceleration sensor with high sensitivity.

Description

technical field [0001] The invention relates to a capacitive micro-acceleration sensor with a symmetrical composite elastic beam structure, which belongs to the field of micro-electromechanical systems. Background technique [0002] The development of MEMS has greatly promoted the progress of sensor technology and realized the miniaturization of acceleration sensors. The capacitive acceleration sensor made by micromachining technology has advantages in measurement accuracy, temperature characteristics, closed-loop measurement and self-inspection using electrostatic force, and easy integration with electronic circuits. It can be widely used in oil exploration, earthquake monitoring, and medical treatment. Instruments, aerospace, weaponry and many other fields have broad market application prospects. [0003] Common micromechanical acceleration sensors are mainly divided into three types based on the sensitive principle: piezoresistive, piezoelectric and capacitive. The basi...

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Problems solved by technology

But usually the elastic beam of this structure is not in the same plane as the center of the sensitive mass, which will cause a large cross sensitivity, that is, the acceleration signal in the non-sensitive direction will also cause a large output

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