Tri-axial accelerometer with giant magneto-resistance effect

Abstract

The invention discloses a tri-axial accelerometer with giant magneto-resistance effect. The tri-axial accelerometer comprises a bonding substrate, giant magneto-sensitive resistors and micro accelerators, wherein the giant magneto-sensitive resistors are arranged on the upper surface of the bonding substrate, and are in positional correspondence to giant magneto-sensitive resistors on the upper surface of a sensitive mass block of the accelerator in each detection direction; the micro-accelerators are arranged above the bonding substrate and are connected with the bonding substrate; and each of the micro-accelerators comprises the sensitive mass block, a ferromagnetic thin film and a cantilever beam. According to the tri-axial micro-mechanical accelerator disclosed by the invention, an overall structural design is adopted, and three accelerators for detection in different directions are integrally manufactured on the same frame, therefore, the tri-axial accelerometer is reasonable in structure, simple in detection circuit, convenient to use, good in reliability and suitable for microminiaturization.

Description

technical field [0001] The invention relates to the related field of micro-inertial navigation technology, in particular to a three-axis micro-mechanical accelerometer with giant magnetoresistance effect. Background technique [0002] At present, the commonly used detection methods of micromachined accelerometers are piezoresistive, capacitive, piezoelectric and tunnel effect, etc. The piezoresistive is based on the principle of piezoresistive effect of highly doped silicon. Pressure-sensitive devices have a strong dependence on temperature, and the bridge detection circuit composed of pressure-sensitive devices will also cause sensitivity drift due to temperature changes; the improvement of capacitive precision is to increase the capacitance area, due to the miniaturization of devices , its accuracy is difficult to improve due to the reduction of the effective capacitance area. The sensitivity of the piezoelectric effect nano sensor is easy to drift, requires frequent cali...

AI Technical Summary

Problems solved by technology

[0002] At present, the commonly used detection methods of micromechanical accelerometers are piezoresistive, capacitive, piezoelectric and tunnel effect, etc. The piezoresistive is based on the principle of piezoresistive effect of highly doped silicon, and the Pressure-sensitive devices have a strong dependence on temperature, and the bridge detection circuit composed of pressure-sensitive devices will also cause sensitivity drift due to temperature changes; the improvement of capacitive precision is to increase the capacitance area, due to the miniaturization of devices , its accuracy is difficult to improve due to the reduction of the effective capacitance area

The sensitivity of the piezoelectric effect nano sensor is easy to drift, requires frequent calibration, and is slow to return to zero, so it is not suitable for continuous testing

Tunnel effect nanosensors, the manufacturing process is complex, the detection circuit is relatively difficult to implement, the yield is low, and it is not conducive to integration

[0003] The measurement of the acceleration by the micro-mechanical accelerometer is completed by the force-electricity conversion of the detection device. The detection sensitivity, resolution and other indicators have reached the limit state of sensitive area detection, which limits the further improvement of accelerometer detection accuracy, and it is difficult to meet the needs of modern military and civilian equipment

Images