A Folded Beam High Sensitivity Micromachined Accelerometer

Abstract

A folded-beam-type high-sensitivity micro-mechanical accelerometer comprises an upper cover, a sensitive silicon structure and a lower cover. The upper cover is provided with an upper fixing capacitance plate, the lower cover is provided with a lower fixing capacitance plate, the sensitive silicon structure comprises a fixing frame, a sensitive mass block and folded beams, a stress release groove is formed in each lateral side of the fixing frame, the fixing frame forms matching beams between the stress release grooves and the inner side of the fixing frame, the sensitive mass block is arranged in the middle of the fixing frame and connected onto the matching beams through the folded beams, the upper fixing capacitance plate comprises an upper detection electrode and upper matching electrodes, the upper matching electrodes are arranged around the upper detection electrode, the lower fixing capacitance plate comprises a lower detection electrode and lower matching electrodes, the lower matching electrodes are arranged around the lower detection electrode, the sensitive mass block is positioned between the upper detection electrode and the lower detection electrode, and the matching beams are positioned between the upper matching electrodes and the lower matching electrodes. The folded-beam-type high-sensitivity micro-mechanical accelerometer has the advantages of simple structure, convenience in manufacturing, low cost and small temperature drift.

Description

technical field [0001] The invention relates to the field of micro-mechanical sensors, in particular to a folded-beam type high-sensitivity micro-mechanical accelerometer. Background technique [0002] Compared with traditional accelerometers, micro-machined accelerometers based on MEMS technology have outstanding advantages such as small size, light weight, low cost, and high reliability, so they are widely used in automobile motion state control systems, camera stabilization systems, and sports machinery control In fields such as high-sensitivity accelerometers, as an indispensable part of a precise control system, its role is becoming more and more significant. [0003] At present, there are mainly the following ways to improve the sensitivity of the accelerometer, which are to reduce the electrode gap, reduce the stiffness of the support beam, and increase the mass of the movable mass, among which reducing the electrode gap will easily lead to an increase in the relative...

AI Technical Summary

Problems solved by technology

However, after the stiffness of the support beam is reduced, the influence of temperature drift is more obvious, thus affecting the accuracy of detection

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