Z-axis capacitive micromachined accelerometer

Abstract

The invention discloses a Z-axis capacitance micro-mechanical accelerometer and belongs to the technical field of inertia sensors in a micro-mechanical electronic system. The Z-axis capacitance micro-mechanical accelerometer comprises a glass base, a torsion structure layer combined on the glass base in a bonding mode, and a metal electrode layer sputtered on the glass base. The torsion structure layer comprises four sub-units of the same structure. If one of the four sub-units rotates in the clockwise direction or the anti-clockwise direction in 90 degrees, 180 degrees and 270 degrees, the rest of the four sub-units are obtained respectively. Sensitivity of the mechanical accelerometer is improved by reducing the ratio between opposite area of capacitor electrode plates and a distance between the electrode plates; due to the totally symmetric torsion structure layer, the structural common mode rejection ratio is large and zero point deviation of an output signal is reduced.

Description

technical field [0001] The invention discloses a Z-axis capacitive micro-machine accelerometer, which belongs to the technical field of inertial sensors in micro-machine electronic systems. Background technique [0002] Micromachined accelerometers are one of the most successful devices in microelectromechanical systems. They have broad application prospects in the military and civilian fields, and have huge social and economic benefits. Improving performance indicators is currently the research focus in the field of micromachined accelerometers. . [0003] The Z-axis capacitive micromachined accelerometer acts on the mass block through the acceleration in the Z-axis direction. The mass block drives the movement of the support beam, and the comb teeth or flat plate on the mass block also move correspondingly. When the comb tooth or flat plate and the fixed When the distance between the capacitance pairs formed by the plates or the distance between the pole plates changes, i...

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Problems solved by technology

Yang Zhenchuan, Liu Xuesong, Hao Yilong, etc. from Peking University introduced a comb-tooth capacitive Z-axis accelerometer and its preparation method (CN 1605871A), including a glass base, movable electrodes and fixed electrodes, support beams and anchor points, movable The electrode takes the support beam as the axis, and its two sides have poor quality. It belongs to the torsion Z-axis capacitive micromachined accelerometer, but because the change of the detection capacitance only depends on the torsion angle of the support beam, and has nothing to do with the fixed electrode, so the sensitivity of the accelerometer smaller

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