A full quartz differential resonant pressure sensor chip

Abstract

The invention relates to an all-quartz differential-type resonating pressure sensor chip. The all-quartz differential-type resonating pressure sensor chip comprises a push rod, wherein the tail end ofthe push rod is connected with a substrate by virtue of a flexible hinge, a first two-end clamped tuning fork and a second two-end clamped tuning fork connected to two sides of the tail end of the push rod form a differential working unit; a side surface substrate of the push rod is provided with a reference unit of a third two-end clamped tuning fork as a correction working unit, and a stressedend of the push rod is connected to an accessory pressure sensitive structure; the two-end clamped tuning forks, the flexible hinges, the push rod and the substrate are integrally machined by quartz crystals; and the accessory pressure sensitive structure converts the pressure to the displacement, the push rod is pushed to rotate around the flexible hinge, two quartz tuning fork beams of the working unit are driven to deform, one quartz tuning fork beam suffers the pull stress, the frequency increases, the other one suffers the pressing stress, the frequency decreases, the frequency differencebetween the two quartz tuning fork beams is in a proportional relation with the pressure, and the measured pressure is obtained by measuring the frequency difference; and the all-quartz differential-type resonating pressure sensor chip has the advantages of digital signal output, high sensitivity and good interference resistance.

Description

technical field [0001] The invention belongs to the technical field of resonant pressure sensors, in particular to an all-quartz differential resonant pressure sensor chip. Background technique [0002] The differential resonant pressure sensor not only has high sensitivity and precision, but also can effectively suppress conjugate interference such as temperature drift and time drift. At present, although there is a plan to use SOI technology, use silicon dioxide as a sacrificial layer, and integrate silicon materials to manufacture resonators, silicon resonators have problems such as low vibration frequency, poor sensitivity, and low quality factor Q value. Therefore, it is a better choice to use single crystal quartz crystal material to make the resonator. However, quartz resonant pressure sensors with differential outputs are relatively rare. There are certain problems with the limited number of quartz resonant pressure sensors with differential output structures. For...

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Problems solved by technology

For example, the differential mechanism is complicated, the process is complex and cumbersome, the cost is high, and the volume is large

Moreover, the resonant components are bonded to the pressure conversion components. Due to the different thermal properties of the materials, the temperature influence is very serious, and the aging and creep of the glue used for bonding are also unavoidable problems.

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