MEMS accelerometer

Abstract

An MEMS accelerometer comprises a substrate, an acceleration sensitive chip and an integrated circuit, wherein the acceleration sensitive chip and the integrated circuit are arranged on the substrate, a temperature sensor is further arranged on the substrate and is adjacent to the acceleration sensitive chip, and the acceleration sensitive chip comprises a plurality of measurement bodies. Each measurement body comprises a mass block and a comb tooth structure, wherein the comb tooth structure comprises movable comb teeth extending from the mass block and fixed comb teeth, the movable comb teeth and the fixed comb teeth are arranged at intervals and form a difference detection capacitor, the comb tooth structure is divided into multiple groups, the multiple groups of comb teeth structures are divided into a first part and a second part, the variation direction of movable intervals of the comb tooth structure of the first part and the variation direction of movable intervals of the comb tooth structure of the second part are opposite, and one group of the comb tooth structure and one group of the comb tooth structure of the second part respectively output an electric signal. The MEMS accelerometer resolves the problems that a traditional MEMS accelerometer is large in temperature factor and large in temperature hysteresis.

Description

technical field [0001] The invention relates to a MEMS (micro-electromechanical system) accelerometer, which belongs to the category of MEMS inertial technology. The invention mainly solves many problems of the sensitive chip of the MEMS accelerometer, especially temperature characteristics, measurement accuracy, and environmental adaptability to shock and overload. It can be used as an acceleration sensor for inertial measurement and inertial navigation in the fields of aviation, aerospace, weapons, etc. It can also be used as an acceleration sensor for bridge health monitoring, geological exploration and other fields. Background technique [0002] The principle prototypes of MEMS accelerometers are mostly developed in China, but they are currently facing many difficulties in engineering. Therefore, domestic MEMS accelerometers have not been used on a large scale. The first is the accuracy problem. There is still a large gap between the bias and the stability of the scale f...

AI Technical Summary

Problems solved by technology

[0007] refer to Figure 4 , when the temperature or stress changes cause the movable comb to deform, the movable gap between the measuring body comb structures in the prior art increases or decreases at the same time, resulting in the cumulative increase of the differential capacitance change, resulting in a common mode error, resulting in acceleration Gauge is unstable under temperature changes or stress changes

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