Design Of Micro-range Linkage Film Pressure Sensitive Chip

MEMS pressure sensor is the earliest MEMS microsensor with a huge market share.It has been widely used in transportation,process control,medical,and other industries because of its small size,fast response,simple structure,and easy processing of output signals.With the gradual maturity of MEMS technology and the demand for micro-pressure measurement,the development of MEMS pressure sensors in the direction of micro-range is promoted.This subject has designed a micro-range linkage thin-film pressure sensitive chip(CPSSLF)for the needs of small-range pressure measurement.The finite element software COMSOL Multiphysics was used to model and simulate the chip structure,and the performance of the pressure-sensitive structure of the square diaphragm and the pressure-sensitive structure of the circular diaphragm was studied.Through analysis,it is concluded that the pressure-sensitive structure of the linkage membrane is more suitable for the circular diaphragm.Through simulation analysis,the influence of the size of the linkage thin-film pressure-sensitive chip on the linear working range is studied,and the pressure-sensitive chip size is determined.The impact of the size of the pressure-sensitive chip on the fracture strength of single crystal silicon is also analyzed,and the overload capacity of the pressure-sensitive chip is improved by reducing the height of the lower cavity.The analysis results show that the designed linkage film pressure-sensitive chip has a range of 0-7KPa,of which the linear working range is 3.4-7KPa,the sensitivity is 0.693 p F/KPa,the non-linearity is 1.22%FS,and its overload capacity is about12 MPa,about It is 119 times the atmospheric pressure.Finally,the performance of the CPSLF and TMCPS structures under the same size is studied.The result analysis shows that the linear working range of the CPSLF structure is about 2.1 times that of the TMCPS structure.Compared with the TMCPS structure,the CPSSLF structure has a broader application prospect in micro-range applications.Based on SOI technology,this project designed a linkage thin-film pressure-sensitive chip.By optimizing the size of the pressure-sensitive chip,the linear working range,sensitivity,and anti-overload capability of the micro-range pressure-sensitive chip are improved.Also,the manufacturing process flow of the linkage thin-film pressure-sensitive chip and the required layout in the process flow are designed,which provides a feasible solution for the production and preparation of the pressure-sensitive chip.