Design And Implementation Of Digital Pressure Sensor

Sensor is a tool for human to obtain information．Through the development of humanautomation process， its development trend is miniaturization， intelligent andnetworked．Pressure sensor，as one of the most important application of sensor technology，the research of its miniaturization，intelligent and network has more practical significance．Using silicon piezoresistive effect and microelectronics technology，diffusion siliconpressure sensor is a new type of pressure sensor．By packaging technology of MEMS（Micro-Electro-Mechanical Systems）doing the primary packaging，such as T0packaging，connecting with weak signal amplification circuit，and doing the secondarypackaging，can complete products to measure the pressure of gas or liquid．Due to thesecondary packaging，for mass production，the pressure sensor package cost will behigher，and the volume is bigger．So，we need to research new MEMS packagingtechnology for reducing costs，decreasing volume，and ensuring its reliability．Diffusionsilicon pressure sensor is widely used with its high precision，good stability，low price，easy to miniaturization and the advantages of mass production．However，the materialproperties of semiconductor silicon such as pressure resistance coefficient，P-N junctioncharacteristics are a function of temperature，so the output of diffusion silicon pressuresensor has temperature correlation．The output should be temperature compensated．Inrecent years，with the rapid development of control technology，computer technology andbroadband network technology， using a sensor independently has fewer and feweroccasions， then a multi-sensor system which used to realize multiple parametermeasurement and control object．That puts forward higher requirements on sensor，such ashigh accuracy，good reliability，easy networking and with the function such as informationprocessing and testing．Therefore，the development of high reliability and fully functionalnetworked pressure sensor is becoming the concerned focus．In view of the development trend of the pressure sensor，this topic research thestructure and properties of the diffusion silicon pressure sensor， temperaturecompensation，weak signal detection and reliability．Designing the hardware circuit and software program．Having a simple introduction to CAN bus specification，a intelligentnodes with CAN bus communication is designed．The MEMS packaging technology wasstudied，and a pressure sensor is designed based on system level packaging technology．...