Research And Mechanics Property Analysis Of Elastic Element Of Pressure Sensor

Sensor technology is the most important sign of the level of the development of modern science and technology, and is one of three greatests technique of the information(include communication technique and calculator technique). Si pressure sensor is the mostly widely used among all the kinds of sensors. The conventional piezoresistive pressure sensor are made by forming diffused strain gauges in a Wheatstone bridge configuration on the thin silicon diaphragm. A known limitation of these silicon-based devices using isolation by reverse biased pn-juncitons is the rising junction leakage current at elevated temperature up to 120°C,which make them in unstable state, Research on high temperature micro type pressure sensor become necessary with the requirement for piezoresisitive pressure sensor to operate in high temperature and harshment environment. Typical such areas are in oil industry and a host of others.The working temperature and insulating function of pressure sensor can be enhanced with the technology of separation by implanted oxygen. The core of this paper is to discuss the stress distribution of strain diaphragm of high temperature micro type pressure sensor.First, stress distribution of high temperature micro type pressure sensor strain diaphragm is deduced by elastic mechanics theory and theory of plates and shells and it will provide reference for the disposition of sensing resister in strain membrane. Then a series of micro high temperature mirco type pressure sensor chips are analysed and simulated by using ANSYS software on the account of Finite-Element Analysis (FEA) theory. The stress distribution of strain diaphragm and rationality of the monolayer model and the effect of dimension of strain diaphragm to the difference between stress is demonstrated carefully and reliable result is achieved. In addition the paper investigates how to make the elastic element structure optimization come true by using the ANSYS software,And establishes the mechanics model,optimization parameter model,optimization mathematics model for the elastic element of high temperature pressure sensor,at the same time,discusses the design space,programs analysis file and optimization control file are worked out by the ANSYS parameter design language.The optimization is obtained after computing and the optimization result indicates that the method is efficient to optimize the elastic element structure.The output-input relation of optimum and the relation between design variable and object function are simulated by using ANSYS. At last analysis of dynamic characteristic of sensor elastic element structure is studied in modal and harmonic and transient structure dynamics by ANSYS software, and well dynamic characteristic is derived from the analysis result.The creativity points in the paper are:1. Prove the rationality of the monolayer model using numerical computing method.2. Thoroughly analysed the strain membrane, including how width-height ratio and thickness affect the theoretical output of the high temperature pressure sensor.3. Sensor sensitivity is enhanced through the optimization of high temperature pressure strain diaphragm by using ANSYS software.4. The anisotropic etching the silicon cup was simulated in special MEMS software-IntelliSuite. Simulated result demonstrated the feasibility of design scheme.5. Dynamic characteristic of sensor elastic element is studied, and well dynamic responsing characteristic is derived from the analysis result.