Resonator based on electrostatic driving and differential piezoresistance detection and pressure sensor thereof

Abstract

The invention belongs to the technical field of sensors, in particular to a resonator based on electrostatic driving and differential piezoresistance detection and a pressure sensor thereof. The pressure sensor comprises a cover cap, a resonator, a pressure sensing structure and a base, the cover cap, the resonator and the pressure sensing structure are rigidly connected through bonding to form avacuum cavity, and an electrostatic driving electrode, a first mass block, a second mass block, a resonance beam, a piezoresistive strip and a first connecting block are located in the vacuum cavity;and the base is in rigid connection with the pressure sensing structure through bonding and is not in contact with the pressure sensing film. An in-plane dynamic balance resonance mode of the annularresonance beam is adopted, the Q value of the sensor is increased, and the thermal elastic loss is reduced; and the working mode of electrostatic driving / differential piezoresistance detection is adopted, the output signal strength of the sensor is improved, the temperature of the resonator can be represented in situ, and the pressure measurement precision is improved through temperature compensation of the sensor.

Description

technical field [0001] The invention belongs to the technical field of sensors, in particular to a resonator based on electrostatic drive and differential piezoresistive detection and a pressure sensor thereof. Background technique [0002] Micro-Electro-Mechanical System (MEMS for short) resonant pressure sensor is a high-end pressure sensor with a detection accuracy better than one ten-thousandth. Detection, process industry and other fields have a wide range of application requirements. It has many advantages such as easy digital integration, compact structure, small size, light weight, low power consumption, and mass production. [0003] The manufacturing materials of MEMS resonant pressure sensors are mainly quartz and single crystal silicon. Both materials have excellent mechanical properties with almost no mechanical fatigue and creep, but single crystal silicon has various processing methods, smaller device volume, and lower manufacturing costs. Etc. Its core stru...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of signal detection, temperature compensation and processing of resonant pressure sensor, such as small detection signal, inaccurate temperature collection and difficult processing, the present invention proposes a resonator based on electrostatic drive and differential piezoresistive detection, the resonator The device 2 includes a resonator frame, a ring resonant beam 24, 4 first connecting blocks 23, 4 first mass blocks 27, 4 second mass blocks 26, 4 support beams 25, 8 piezoresistive bars 22 and 2 An electrostatic driving electrode, the ring resonant beam 24 is arranged at the center of the resonator frame, and 4 first connection blocks 23 are evenly arranged on the coaxial peripheral ring of the ring resonator beam 24, and its inner side is rigidly connected with the ring resonator beam 24; 4 Each first mass block 27 is evenly arranged on the coaxial inner ring of the annular resonant beam 24, and each first mass block 27 is located in the middle of two adjacent first connecting blocks 23, and its outer side is rigidly connected to the resonant beam; Four second mass blocks 26 are evenly arranged on the coaxial peripheral ring of the annular resonant beam 24, the inner side of each second mass block 26 is rigidly connected with the resonant beam and the first mass block 27, and the outer side of each second mass block 26 Rigidly connected to the support beam 25; the inner center positions of the four support beams 25 are respectively rigidly connected to the four second mass blocks 26. The two ends of each support beam 25 are connected to the resonator frame through piezoresistive strips 22; two electrostatically driven The comb-toothed electrodes arranged on the outside of the two support beams 25 opposite to the electrodes and the comb-toothed electrodes arranged on the base frame together constitute the electrostatic drive electrodes

Images