基于MEMS工艺的热膜式流量传感器芯片的研制

Research and fabrication of hot-film flow sensor chip based on MEMS

基于托马斯(Thomas)流量计原理,研制了热膜式流量传感器芯片。该敏感元件采用MEMS工艺,制作出了3μm厚度的带固支边的敏感膜结构,在膜上设计有一只加热电阻器和一组微型热敏电阻器。通过工艺研究,解决了膜上Pt电阻与基底的热匹配问题,并将该芯片应用于汽车进气流量传感器研制中。测试结果表明:使用该芯片流量传感器的测量准确度为1%FS,满足发动机系统使用要求。

Hot-film flow sensor chip based on Thomas flow meter theory is researched and fabricated.This sensitive device uses MEMS technology and sensitive membrane structure with 3 μm thickness fixed support edge is fabricated,a heating resistor and a set of micro temperature sensitive resistor are designed on the film.By a series of technique researches,key problems of technique are resolved.Temperature matching of Pt resistor and substrate are very well,this chip is used in research of automotive intake flow sensor.Test result shows that the measurement accuracy of this chip flow sensor is 1 %FS,which will correspond with engine system standard demand.