Micromachined capacitive accelerometer with crab-shape

Abstract

Perhaps more popular than the piezoresistive type are the capacitive type of micromachined accelerometers. The capacitive accelerometer has many fine characteristics, such as simple structure, high sensitivity, strong ability of resisting disturbance, fast dynamic response and so on. It can also work under abominable condition. So it is occupying an important status in the technology of electronical measurement and being used in many kinds of metrical systems. In this paper, the capacitive accelerometer (CA) we will introduce and design is a parallel plate CA with crab-shape. It will detect the acceleration signal by the change of distance between two electrode plates, and its design standard came from the industrial requirements ofKENTRON Company. The whole paper can be divided into four main phases-introduction, study, design and analysis. At first, we have introduced the purpose and background of this thesis, and then the study and the discussion of relative literature. The content of these articles is mainly about the basic principle, types and applications of micro-sensors and this information will be very helpful to the design and analysis ofmy own CA. The course of design is primarily structure design. The main structures of CA are parallel plate structure and cylinder structure. The parallel plate structure is chosen for our CA after we did the comparison of performance and technique of making between these two types of structures. We use the concentrative mass as the top electrode plate and four beams are connected on the two sides of the plate separately.