Recently, as a automobile becomes more electronic and intelligent, MEMS(Micro Electro Mechanical System) sensors lead the technology and market of automotive sensor by overcome limitation of size, accuracy and reliability of mechanical sensors. Accelerometer, gyro, and pressure sensor are mainly studied MEMS sensor in the automobile field. Specially, intensification of safety regulation has increased the requirement and interest of the accelerometer. There are piezoelectric, piezoresistive, capacitive type in the sensing method of the accelerometer. Among these, piezoelectric method has high sensitivity feature with a simple manufacturing process.
In this paper, we fabricated Flexural Plate Wave(FPW) accelerometer which sense frequency change of the vibrating piezoplate and found a optimum condition of the piezoplate shape and manufacturing condition to improve performances by using the design of experiment. Therefore, we altered the shape of the piezoplate to rectangular, bridge and bridge with mass structure and changed thickness of a piezoplate. We produced sensor assay with each of the conditions and measured sensitivity, non-linearity, noise, bias drift, cross-axis sensitivity and durability characteristics and then we conducted vehicle test with CDC system.