Micro-acceleration transducer capable of avoiding parasitic capacitance structure, and manufacturing method thereof

Abstract

The invention relates to a micro-acceleration transducer capable of avoiding a parasitic capacitance structure, which comprises a top electrode cover plate, a lower electrode cover plate and a mass block, wherein the top electrode cover plate and the lower electrode cover plate are respectively arranged at the upper end and the lower end of the mass block; the upper surface of the mass block is provided with an upper capacitance gap, and the lower surface of the mass block is provided with a lower capacitance gap; and the lower surface of the top electrode cover plate and the upper surface of the lower electrode cover plate are respectively provided with an isolation groove used for realizing isolation among a top electrode bonding pad, a middle electrode bonding pad and a lower electrode bonding pad. The micro-acceleration transducer is easy to manufacture, stable in working performance and wide in application.

Description

technical field [0001] The invention relates, in particular, to a micro-acceleration sensor avoiding a parasitic capacitance structure and a manufacturing method thereof. Background technique [0002] Micro-accelerometer is a very important micro-inertial device, which has developed very rapidly and has been widely used in different fields. Among them, the capacitive micro-acceleration sensor has the advantages of good temperature stability, high sensitivity, good dynamic response, low noise, etc., and is widely used in various fields, such as various guidance and measurement and control systems, robots, medical instruments, microgravity measurement and high precision exploration, etc. High-performance micro-acceleration sensors are usually designed as a differential capacitive structure with feedback compensation, but it is a difficult problem to detect the small differential capacitance change, and the design of the processing circuit requires reducing the interference of...

AI Technical Summary

Problems solved by technology

However, the upper electrode, middle electrode, and lower electrode of most sandwich structure micro-accelerometers (that is, the bonding surface between the silicon wafer and the silicon wafer) are electrically insulated by insulating materials such as silicon dioxide, which brings a A series of problems, for example, the bonding between silicon wafers with insulating materials (especially the bonding of three-layer silicon wafers or even four-layer silicon wafers) has high requirements and poor bonding strength. In addition, it is more The most important thing is that the parasitic capacitance of the bonding area is relatively large. The parasitic capacitance of the sensor makes its work unstable and affects the measurement accuracy. It has high requirements for the current driving capability of the interface circuit. It is necessary to try to eliminate the influence of the parasitic capacitance on the performance of the sensor.

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