Multi-Bridge Tunneling Magneto-Resistive Dual-Axis Accelerometer

Abstract

The invention relates to a multi-bridge tunnel reluctance dual-axis accelerometer, which includes a support frame one, a support frame two, an X-axis mass block, a Y-axis mass block, an X-axis tunnel magneto-resistance element, a Y-axis tunnel magneto-resistance element, and an X-axis mass block. X-axis fold-back coil, Y-axis fold-back coil, X-axis fold-back coil and Y-axis fold-back coil that are orthogonal to each other are fixed on the X-axis mass block; the two ends of the X-axis fold-back coil and the two ends of the Y-axis fold-back coil are respectively passed through the wire and the support The corresponding electrodes on the frame one are connected; the X-axis tunnel magneto-resistance element and the Y-axis tunnel magneto-resistance element are fixedly installed on the support frame two; the X-axis tunnel magneto-resistance element is located directly above the X-axis turn-back coil; Directly above the Y-axis folded coil, a multi-bridge structure is arranged inside the tunnel magnetoresistive element. The dual-axis MEMS accelerometer based on the multi-bridge tunnel magnetoresistance proposed by the invention greatly improves the limit detection capability and detection sensitivity of the accelerometer.

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 problem is that the bias 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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