Silicon substrate-based quartz resonance acceleration sensor chip with four-beam structure

Abstract

The invention discloses a silicon substrate-based quartz resonance acceleration sensor chip with a four-beam structure. The quartz resonance acceleration sensor chip comprises a periphery silicon substrate support, wherein the periphery silicon substrate support is bonded with a glass substrate; a double-end quartz tuning fork is fixed on a boss of the silicon substrate support through organic gel; and the other end is fixed on a boss of a mass block; the mass block is provided with four cantilever beams supported on the silicon substrate; a layer of metal electrode is arranged at the part (corresponding to the mass block) on the glass substrate; the metal electrode is used for preventing the electrostatic adherence between an acceleration mass block and the glass substrate during the electrostatic bonding; the sensor chip senses the input of the acceleration through the mass block, the double-end quartz tuning fork is thereby transformed, a resonance frequency of the quartz tuning fork is output through a frequency detecting circuit, and an acceleration signal is converted into an electric signal so as to accomplish the digital induction and measurement to the acceleration. The sensor chip has the advantages of good frequency output, small size, high sensitivity, high quality factor and the like.

Description

technical field [0001] The invention belongs to the technical field of micro-mechanical electronics, and in particular relates to a silicon-based four-beam structure quartz resonant acceleration sensor chip. Background technique [0002] At present, high-precision, high-resolution digital acceleration measurement methods have been developed more and more widely, and have broad application prospects in medium and high-precision high-speed digital navigation systems, gravimetry, cruise missiles, and autonomous underwater navigation. The output of this type of accelerometer is a frequency signal, without the loss of accuracy caused by digital-to-analog conversion, and can be combined with a high-precision digital measurement system. At present, the commonly used sensors processed by MEMS are mainly divided into piezoresistive and capacitive. The piezoresistive sensor senses acceleration through a resistor with piezoresistive effect and a beam-mass block with a certain structur...

AI Technical Summary

Problems solved by technology

The above two commonly used acceleration sensors output analog signals, the post-processing circuit is complex, the sensitivity is low, there is an analog-to-digital conversion error, and it cannot be directly combined with a high-precision digital system

At present, there are also a small number of resonant silicon micro-acceleration sensors. Although such sensors output digital signals, they have problems such as low resonance frequency and poor sensitivity. At the same time, they have complex structures, difficult processing, and high costs.

In short, the existing accelerometers generally have problems such as analog output, low sensitivity, and complicated processing.

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