Key Techniques Of Design And Manufacture For Non-driven Silicon Micromechanical Gyroscope

MEMS gyroscope is generally use the Coriolis force to sensitive velocity. At home and abroad, research on MEMS gyroscope mainly with driving part. We developed the MEMS gyoscope without driving part is aimed at the rotating carrier for their own characteristics, mainly for rotating carrier attitude control, which installed on the rotating carrier, use rolling angular velocity as driving force. So it does not has driving part as well as the ordinary MEMS gyroscope, that greatly simplifid the overall structure of the gyroscope, thus reduced the processing difficult, also reduced manufacturing costs. This gyroscope has not only a simple structure, high reliability, and in the SINS platform using the geographic coordinates of the accelerometer benchmark, through the Coriolis forces effect of capacitance change to detect yaw and pitch angular velocity of the rotation carrier, can sensitive carrier three axial angular velocity and Angle at the same time, namely the gyroscope for a two-directional gyroscope. In this thesis, a bulk micro-machining technology to prepare’the non-drive structure MEMS gyroscope as the study object, research the robustness of the MEMS gyroscope structure, in order to solve the stability of product quality and performance in robust design, proposed micro-structure performance analytical methods based on cantilever rectangular thin plate theory, process improvement based on bulk micromachining technology, steady-state production of MEMS gyroscope based on Statistical process control (SPC) techniques:(1) Analyed non-drive structure MEMS gyroscope work principle and dynamic model, built dynamic formula based on Tait-Bryan angle coordinate transformation, obtained MEMS gyroscope output angle in the relationship of the input angle and the torsional stiffness of the beam, proved the gyroscope can sensitive three axial velocity mechanism in theory. Studied the structural parameters of the gyroscope and error analysis.(2) Ultilized the transient impact performance based on energy method and cantilever rectangular thin plate theory, analysis of the vibration modes of MEMS gyroscope mass, frequency characteristics and transient characteristics, determine a reasonable beam structure. Through beam cross-section characteristics analysis, combined with the anisotropic wet etching characteristics, we changed twice robust design method of the beam structure to enhance the impact. Improve the dynamic performance of the MEMS gyroscope, analysis of the different MEMS gyroscope elastic beam structure, and use the integration method derived curved beam torsional stiffness, the beam characteristics of the MEMS gyroscope is analyzed theoretically. Using the Coventor software suite simulation software to establish the model, simulated and compared centroid offset and defects on the gyroscope.(3) To solve problems of instability caused by uncertainties in the micro-structure processing, proposed improved processing methods based on bulk micromachining technology. Production of the last step for sensitive chip is a small piece separate production, its difficulties and heavy. Put forward the whole piece of making molding and re-designed the masks, production from the device level to the wafer-level, improve product consistency and repeatability, and shorten the production cycle.(4) To resolve uncertainties in the process of MEMS gyroscope performance variation caused by the problem of instability of the product quality, put forward gyroscope stabilization state production based on the SPC statistical techniques,. Analysis to determine the key processes and key parameters of the gyroscope production, and data acquisition, control charts to monitor the key parameters of various processes in the production process to achieve improvements in a timely manner to ensure that the purpose of product quality.Study on MEMS gyroscope dynamic performance analysis and robust design, in the case of changed the cantilever structure, improved the micro-machining technology and SPC steady-state production, reducing the variation of the dynamic performance of MEMS gyroscope, improving the stability of the system performance. This paper presents the research not only for the study of MEMS gyroscope, and for other micro-structure and product characteristics have important application value. In view of this, we study the non-drive MEMS gyroscope is of great significance and value.