Related Techniques Of A New Micro-accelerometer Based On Non-silicon MEMS

MEMS is widely used in many kinds of fields, among which acceleration sensor is significant. The micro inertial acceleration sensor is the key basic component for MIMU (Micro Inertial Measurement Unit), which will be more and more applied in future. The micro-accelerometer produced by MEMS technology can help us minimizing the volume of equipment, integrating function and improving reliability, reducing cost.The main study focus on the design of structure and fabrication techniques of the designed micro accelerometer and the detecting circuit, including the followings:1 The basic theories and detection principles on micro mechanical accelerometer are studied.2 The model of the micro accelerometer is set up based on the design tasks and performance requirements. The so-called sandwich structure is chosen from some typical structures. The electrodes are in the shape of circle with many folded springs to improve the characteristic of the micro accelerometer such as measuring range and stability requirements. The structures of the designed micro accelerometer are simulated by ANSYS software. The micro accelerometer also has the self-test function. The symmetry of the structure can be tested by the detecting circuit easily because of this kind of structure.3 The fabrication techniques of the micro accelerometer are also designed. Some metallic materials are used in the processing instead of Si. The fabrication flow has several main process steps: glass procedure, bonding and release of the micro structure.4 Testing circuit is designed to detect the characteristic of the micro accelerometer. In the detecting circuit, MS3110 which is designed for testing capacitive especially is used to test capacitive and Single chip is used to change parameters inside of MS3110 to ensure it work in an area with good linearity and sensitivity. LabVIEW is used to collect data.The bottom fixed electrode and the mass of the micro accelerometer are produced and tested by the detecting circuit. The result shows that the micro accelerometer produced has good symmetry characteristic.