Sandwich type micro accelerometer with high signal to noise ratio

Abstract

The invention discloses a sandwich type micro accelerometer with a high signal to noise ratio. The micro accelerometer comprises an upper electrode structure layer, an upper bonding contract area, a middle electrode structure layer, a lower bonding contract area and a lower electrode structure layer from top to bottom, wherein the upper electrode structure layer is provided with the upper bondingcontract area bonded with the middle electrode structure layer; the lower electrode structure layer is provided with the lower bonding contract area bonded with the middle electrode structure layer; the upper bonding contract area and the lower bonding contract area form a bonding contact layer; the upper electrode structure layer, the middle electrode structure layer and the lower electrode structure layer are fused and bonded in the upper bonding contract area and the lower bonding contract area to form a self-sealed structure; and the middle electrode structure layer comprises a moveable mass block. Stray capacitance values of the upper electrode structure layer, the lower electrode structure layer and the middle electrode structure layer on a device can be reduced to a large extent, and in case of a same electrode plate interval, the signal to noise ratio property of the sandwich type micro accelerometer can be remarkably improved.

Description

technical field [0001] The invention relates to the research field of micro-accelerometers, in particular to a sandwich-type micro-accelerometer with a high signal-to-noise ratio. Background technique [0002] Sandwich type micro-accelerometer is a device or device for measuring acceleration. It is widely used in industrial control, aviation instrumentation, military and other fields with high signal-to-noise ratio and high measurement accuracy requirements. The traditional sandwich micro-accelerometers mainly have glass-silicon-glass structure and silicon-silicon-silicon (full silicon) structure, and the sandwich micro-accelerometer composed of glass-silicon-glass structure does not have the influence of parasitic capacitance, but its The thermal mismatch problem is relatively large, and the temperature characteristics are poor, which will affect the measurement accuracy of the device. The sandwich micro-accelerometer composed of an all-silicon structure has a small thermal...

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Problems solved by technology

The traditional sandwich micro-accelerometers mainly have glass-silicon-glass structure and silicon-silicon-silicon (full silicon) structure, and the sandwich micro-accelerometer composed of glass-silicon-glass structure does not have the influence of parasitic capacitance, but its The thermal mismatch problem is relatively large, and the temperature characteristics are poor, which will affect the measurement accuracy of the device. The sandwich micro-accelerometer composed of an all-silicon structure has a small thermal mismatch problem and good temperature characteristics, but the silicon-silicon bonding of the device Because the insulating layer is very thin, there is a large parasitic capacitance, which will greatly reduce the signal-to-noise ratio characteristics of the device. The above-mentioned conditions cannot take into account the application requirements of high signal-to-noise ratio and high measurement accuracy of the sandwich micro-accelerometer

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