Design And Research Of A New Type Of Mems Inertial Accelerometers

The MEMS devices produced by the Micro Electro Mechanical System(MEMS) technology can help us minimizing the volume of equipment, integrating function and improving reliability, reducing cost, which is very important for the development of the fields of advanced technology. 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 research of MEMS inertial accelerometer is of great scientific significance.This paper is one part of the UESTC's assignment——"The Design and Research of MIMU"。By the research for MEMS and the MEMS acceleration sensor, This assignment will finish a series of MIMU system,which will be applied to the rocket and the missile guided system.This thesis mainly include following facets:Research the mature MEMS processing technic at the present, develop a type of capacitive acceleration sensor which structure is simple and based on a set of new silicon bulk micromachining process.This paper explained the operating principle of the capacitive acceleration sensor, derive the important formula in detail, researched the mechanical and electricity performance of capacitive acceleration sensor. A new type of four central suspension beams structure is designed and optimum designed.In order to calculate the deflection parameters of cantilever beam, a static, mode and harmonic finite element analysis (FEA) using the ANSYS Finite-Element program is performed. The results derived from FEA are well analyzed for the discipline of structure and its displacement, resonant frequency and mode. By these analyses, optimization design and arts design are performed.Discussing the influence of the electrostatic force upon the system function making good use of this electrostatic force,we can design to open-loop system and closed-loop servo system. choosing suitable feedback and bias voltage and creating a electrostatic servo system will raise the quantity range and stability.