Multi-bridge tunnel magnetic resistance biaxial accelerometer

Abstract

The invention relates to a multi-bridge tunnel magnetic resistance biaxial accelerometer, which comprises a support frame I, a support frame II, an X-axis mass block, a Y-axis mass block, an X-axis tunnel magnetic resistance element, a Y-axis tunnel magnetic resistance element, an X-axis inflection coil and a Y-axis inflection coil. The X-axis inflection coil and the Y-axis inflection coil are fixedly arranged on the X-axis mass block; the two ends of the X-axis inflection coil and the two ends of the Y-axis inflection coil are connected with corresponding electrodes on the support frame I through wires respectively; the X-axis tunnel magnetic resistance element and the Y-axis tunnel magnetic resistance element are fixedly arranged on the support frame II; the X-axis tunnel magnetic resistance element is arranged right above the X-axis inflection coil; and the Y-axis tunnel magnetic resistance element is arranged right above the Y-axis inflection coil. Multi-bridge circuit structures are arranged in the tunnel magnetic resistance elements. With the biaxial MEMS accelerometer based on the multi-bridge tunnel magnetoresistance, the limit detection capability and the detection sensitivity of the accelerometer are greatly improved.

Description

technical field [0001] The invention relates to the technical field of micro-electromechanical systems and micro-inertial devices, in particular to a multi-bridge tunnel reluctance dual-axis accelerometer. Background technique [0002] The detection methods of MEMS accelerometers include piezoresistive, piezoelectric, capacitive, resonance tunneling, and electronic tunneling. Capacitive detection gyroscope is currently the mainstream detection method. It has the advantages of high precision, good stability, suitable for batch processing and easy integration. Device failure. Although the noise level and detection accuracy of capacitive gyroscopes have been improving, they are still limited by the interface circuit resolution, parasitic capacitance, and process technology. The detection resolution has reached the limit, and the noise level is difficult to break through 0.1° / h; The inherent temperature of the micro accelerometer for resistance effect detection limits its appl...

AI Technical Summary

Problems solved by technology

Capacitive detection gyroscope is currently the mainstream detection method. It has the advantages of high precision, good stability, suitable for batch processing and easy integration. Device failure

Although the noise level and detection accuracy of capacitive gyroscopes have been improving, they are still limited by the interface circuit resolution, parasitic capacitance, and process technology. The detection resolution has reached the limit, and the noise level is difficult to break through 0.1° / h; The inherent temperature of the micro accelerometer for resistance effect detection limits its application, and it is difficult to improve its sensitivity; the sensitivity of piezoelectric effect detection is easy to drift, requires frequent calibration, and is slow to return to zero, so it is not suitable for continuous testing; the detection sensitivity of resonance tunneling effect is higher than that of silicon The piezoresistive effect is an order of magnitude higher, but the detection sensitivity obtained by the test is low. The existing problem is that the fraudulent paper voltage is easy to drift due to the accelerometer drive, resulting in the accelerometer not working stably; the electronic tunnel effect detection manufacturing process is extremely complicated, and the detection circuit is also Relatively difficult to implement, low yield, difficult to work properly

[0003] In 2008, Harbin Institute of Technology disclosed a dual-axis accelerometer with a comb-shaped electrode structure. In the comb-tooth capacitive accelerometer, each movable comb is perpendicular to the edge of the proof mass and placed parallel to the sensitive direction, while The fixed combs are equally spaced on both sides of the moving combs to form a differential capacitance pair. However, this structure requires each fixed comb to be bonded to the substrate separately, which greatly increases the difficulty of the process and is not conducive to the yield. improvement

At present, the detection equipment for biaxial acceleration detection is not perfect, and the limit detection ability and detection sensitivity of the accelerometer used are not high.

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