Related Techniques Of Micro-Accelerometer Based On Metal And Multi-Beam Disc Mass

Accelerometer is a typical inertial navigation sensor. With thedevelopment of MEMS (Micro-electro-mechanical-systems), MEMSaccelerometer sensors play more important role in industry market today.Miniature Inertial Measurement Unit (MIMU) which comprises ofmicro-accelerometer and micro-gyroscope has irreplaceable effect in inertialmeasurement. Especially in recent years, industry needs higher precisionMIMU devices in consumer electronics, Aeronautics and Astronautics andautomobile electronics applications. Hence, it is necessary to research anddevelop higher precision, higher scale, lower power consuming and lowercost micro-accelerometer utilizing MEMS technology.This thesis developed a novel micro-accelerometer based on metal andmulti-beam disc mass. This accelerometer adopts metal materials as the mainstructure material because metal has higher fracture toughness than siliconmaterials, and metal materials can prevent emerge of fracture, improveanti-force capability.This thesis did some researches from the following several points: 1. This thesis improves the process of micro-accelerometer. This thesisresearches top and bottom electrodes and basic process flow. And, this thesisfabricated the bottom and middle electrodes successfully. It’s time to detectsingle capacitance.2. This thesis constructs3-D model of micro-accelerometer and carriesout some FEM analysis for damping of this accelerometer withCOVENTORWARE software. This thesis constructs3D model of theaccelerometer utilizing COVENTORWARE FEM software, and computesdamping situation of micro-accelerometer in different temperature, differentgas and different distance between middle electrode and bottom electrode,compares damping situation of mass with holes and without holes.3. This thesis researched closed-loop control system ofmicro-accelerometer. This thesis verified phase-sensitive demodulationcircuit and PID control circuit by Labview software. This thesis tests thecapacitance of bottom capacitance of micro-accelerometer utilizing AD7747evaluation board. Finally, this thesis designs the hardware test circuit withAD7747chip.