Analysis Of Residual Stresses On Micromachined Z-Axis Vibrating Rate Gyroscope And Structural Optimization Design

Sillicon micromachined vibratory gyroscope is a new kind of gyroscopes developed in the last ten years, which is an important research branch of MEMS (Microelectromechanical System). After more than ten years' hard work, we have had the capability of researching and developing the MEMS inertia instruments. However, there is a wide disparity on industrialization of sillicon micromachined gyroscopes between our country and other advanced foreign country. An important causation is the poor performance of gyroscope caused by residue stress, which is result from the unadvanced techniques and the lack of design experience. First of all, based on the principles of gyroscope dynamics and material mechanics, this thesis dose a general research on the operation scheme and structural design of micromachined vibratory gyroscope. Second, the thesis deduces the cause and distributing of the residue stress, through the analyzing of the process of silicon micromachined gyroscopes and making the use of ANSYS FEA model. And a formula of residue stress and frequency also has been deduced. Third, several structures of beams has been suggested, on the basis above. And choose the folded beam to replace the straight beam, after simulate by ANSYS. Finally, with reference to the test results of the two gyroscope samples, the conclusion that fold beam is better than the straight beam on stress release is farther improved.