Silicon substrate double-paddle structure quartz beam resonant micro pressure sensor

Abstract

A silicon substrate double-paddle structure quartz beam resonant micro pressure sensor comprises a shell body. A cavity of the shell body is communicated with atmosphere through a pressure hole. A sensor chip is arranged inside the shell body cavity and composed of a quartz beam substrate, a silicon substrate and a glass substrate. An air inlet of the glass substrate is opposite to the pressure hole in the bottom of the shell body, the silicon substrate is sealed with the glass substrate, the quartz beam substrate is stuck on a cam of the silicon substrate, a bonding block and two electrode pins on the quartz beam substrate are connected, a press ring and the upper portion of the shell body are connected in a threaded mode. A threaded hole in the press ring is communicated with the cavity of the shell body, and two islets are formed in two back corrosion concave grooves in the bottom of the silicon substrate. Inverse piezoelectric effect of quart is used to drive self-oscillation of a quartz beam. When vibration frequency equals to inherent frequency of the quartz beam, resonance happens. The resonance frequency is detected by a closed-loop control system, variation of the resonance frequency represents size of gas pressure to be measured, and therefore measurement of outer air pressure is achieved. The silicon substrate double-paddle structure quartz beam resonant micro pressure sensor is high in sensitivity, accuracy and resolution and the like.

Description

technical field [0001] The invention relates to a quartz resonant pressure sensor, in particular to a silicon-based double-island structure quartz beam resonant micro pressure sensor. Background technique [0002] The pressure sensors on the market mainly include capacitive, piezoresistive and resonant. Capacitive and piezoresistive outputs are analog quantities, and high-precision conditioning circuits must be used to process weak signals. These factors will inevitably lead to a decrease in measurement accuracy; and resonant The pressure sensor uses the pressure change to change the resonant frequency of the object, so as to indirectly measure the pressure by measuring the frequency change, and its output is a quasi-digital frequency signal, which has high measurement accuracy, high sensitivity, high resolution, strong anti-interference ability, and It is suitable for long-distance transmission without reducing its accuracy, and is more suitable for high-precision detection...

AI Technical Summary

Problems solved by technology

At present, the research on MEMS resonant pressure sensors at home and abroad is mainly silicon micro-resonant pressure sensors. The elastic elements and sensitive elements of the sensors are all made of silicon materials and processed by silicon technology. The disadvantage is that it is difficult to process complex high-quality factors. Resonator structure, and it is difficult to excite and detect the resonator

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