Design Of A Large Range Of Capacitive Accelerometer

In this paper, a design of large bulk silicon process based on differentialcapacitive micro accelerometer. Through theoretical analysis and finite elementanalysis software ANSYS to simulate the accelerometer microstructure.Analysis ofthe static and dynamic performance, and realizes micro concrete design structureand optimization.In this paper, the design of accelerometer with differential capacitanceprinciple, adopted the "sandwich" structure of glass silicon glass. This design canrealize larger mass, high sensitivity. This design uses the straight8arm type elasticbeam structure, further sensitivity adjustment range and the sensor can be adjustedby changing the thickness of the elastic beam structure.Through the finite element method using ANSYS on the micro mechanicalaccelerometer static, modal, harmonic response characteristic and the simulationand analysis. The micro structure was established using MATLAB, to achieve thedesired effect. The micro structure of beam thickness40μm are processed, themicro structure of the area is2×2mm2. Analysis shows that when the capacitor gapis7μm, simulation results show that the sensor impact can reach±150000g, rangeis±100000g. And the first-order natural frequency of the structure of122.3KHz,can effectively reduce the external low frequency interference. Through thediscussion on the key technologies in the process. The corrosion and compensationand ICP deep groove etching of packaging technology, and makes a comparativeanalysis, design the circuit diagram.