Capacitive micro inertial sensor with self calibration function

Abstract

The invention relates to a capacitive micro inertial sensor with a self calibration function. An existing sensor with the self calibration function is small in calibration range. According to the capacitive micro inertial sensor with the self calibration function, one sensor mass block is a rectangular silicon slice etched with grid-shaped wells, two corresponding ends of the sensor mass block are connected with anchor points through silicon supporting beams, and rectangular silicon strips are respectively arranged the other two corresponding ends of the sensor mass block. Two driver mass blocks are arranged at two sides of the sensor mass block, an annular groove is formed in the middle of each driver mass block in an engraved mode, movable mass block driving silicon strips and driver driving silicon strips are arranged at two sides of each driver mass block, and the silicon strips connected with the sensor mass block form a mass block driving capacitor along with the corresponding mass block driving silicon strips. Comb tooth strips fixing the driving silicon strips and the movable driver driving silicon strips form a driver driving capacitor. Comb-shaped silicon strips and fixed detection silicon strips connected with the sensor mass block, a grid electrode and an interdigital aluminum electrode on the surface of a substrate form a detecting capacitor. The capacitive micro inertial sensor with the self calibration function increases the mass block driving capacitance, further reduces driving voltage, increases the mass of an oscillator, and reduces Brown noise.

Description

technical field [0001] The invention belongs to the technical field of micro-electronic machinery, relates to a micro-inertial sensor, in particular to a high-precision micro-inertial sensor with a self-calibration function. Background technique [0002] In the past ten years, accelerometers made with micro-mechanical technology have developed rapidly, mainly including optical accelerometers, electromagnetic accelerometers, and capacitive accelerometers. Among these sensors, the capacitive acceleration sensor is the most widely developed type of acceleration sensor due to its small temperature coefficient, high sensitivity, and good stability. With the development of the acceleration sensor, the calibration method of the acceleration sensor has also been developed rapidly. Commonly used calibration methods for acceleration sensors include 1g dynamic rollover test, high-g value centrifuge test, vibration and shock test, etc. When traditionally calibrating the acceleration s...

AI Technical Summary

Problems solved by technology

This calibration method often requires high-precision instruments to provide acceleration signals, which is expensive and complicated to operate. Later, some people have studied the use of electrostatic force to self-calibrate the sensor to replace the inertial force generated by external acceleration, which can reduce costs. The applied voltage easily exceeds the working voltage of the acceleration sensor

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