Integrated Design And Implementation Of Three-axis Silicon Micro Accelerometer

Micromechanical accelerometers with advantages in small size, long durability, low power and easiness for volume-production have been widely implemented in many fields such as battlefield missile midsection guidance, smart bomb and all sorts of situations compared lower precision. In company with the development of science and technology, also the requirement of military and commercial, most of all as the important part of Micro Inertial Measurement Unit (MEVIU), high precision and three-axis monolithic integration micromechanical accelerometers has widely researched at present.In the thesis, a difference capacity micromechanical accelerometer is achieved, and is preliminary tested with matching the interface detection circuit. The main works of this thesis are as following:1. The mathematical models of linear and pendulum acceleration are established, with the optimization objective of maximum detection sensitivity, the sensitivity capacity structures and elastic fixing structures are designed, last the slide flim damping and squeeze flim damping of the structures are discussed.2. A MEMS integrated design methodology is adopted. System level models are established, the resonance frequency and resonance time are simulated. Solid models are established, the static analysis and the model analysis are accomplished. Technology layout and process are designed.3. Several sorts of little capacity sensing circuit are researched, based on the theory of charge amplifier, a scheme of switch phase sensitivity demodulate is designed, according the experiment, the result proved it's a valuable interface circuit.4. The three-axis micromechanical accelerometer is processed, and preliminary test is accomplished, the result is that the sensitivity of X axis accelerometer and Z axis accelerometer are 56.1mV/g and 32.6 mV/g.In the thesis, a MEMS integrated design methodology is adopted, it effectivelyenhances the sensitivity of the accelerometer and has the important reference value to the designing level.