【作者】 袁圆；

【导师】 刘胜；

【作者基本信息】 华中科技大学 ， 精微制造工程， 2009， 硕士

【摘要】 随着现代科学技术的高速发展,汽车电子化、智能化的程度越来越高,传感器作为汽车控制系统的关键器件,其使用数量和技术水平决定了汽车控制系统的性能。本论文主要研究了一种扩散硅压力传感器,该传感器以硅薄膜为弹性膜,利用光刻、掩膜、溅射等微加工工艺和隔离封装方法制成。扩散硅压力传感器在汽车电子领域主要可用于检测发动机润滑油压力、轮胎空气压力、进气歧管压力、共轨压力等。本论文的主要研究内容包括:(1)简述了硅的压阻效应、压阻系数等,在此基础上给出了压力传感器芯片的工作原理和电路结构,介绍了传感器芯片的常见结构以及制作的工艺流程;(2)在有限元软件ABAQUS中通过详细的步骤对传感器芯片的应力、应变进行模拟分析,特别记录了一条路径上各节点的两个正交应力,分析了压敏电阻布置的最佳区域,粗略计算了芯片的灵敏度;(3)简要介绍了阳极键合方法,分析了是否封接玻璃衬底对传感器输出的影响;分析了不同杨氏模量、不同厚度的贴片胶对传感器输出性能的影响;(4)介绍了压力传感器的隔离式封装,通过有限元方法模拟了不同厚度、不同波纹厚度、不同波纹数的波纹膜片对传感器输出性能的影响;实验比较了封装不同参数波纹膜片时传感器的输出,选择了较优的一组参数;(5)分别通过实验和模拟的方法作出了隔离式封装传感器的温度漂移曲线,设计了两种结构来改善传感器的温漂,有限元模拟的结果证明的结构的可行性。更多还原

【Abstract】 Along with the rapid development of modern science and technology, automobile is becoming more and more electronic and intelligent. As the key device of automotive control system, the use quantity and technology level of sensor determine the automotive performance. A diffused silicon pressure sensor which adopts silicon wafer as elastic membrane, is developed by micromachining techniques such as photolithography, mask, sputtering etc. and methods of stress isolation package. The diffused silicon pressure sensors in automotive electronic field are mainly used to detect engine oil pressure, tire pressure,intake manifold pressure and common rail pressure etc. The thesis mainly comprises 4 parts:(1) Based on the piezoresistive effect, piezoresistive coefficient of silicon, the working principle and the circuit structure of the sensor chip are briefly introduced. In addition, the fabrication processes of regular structure of the sensor chip are studied;(2) The stress and strain of the sensor chip is simulated and analyzed by finite element software ABAQUS in detail. Two orthogonal stresses of each node on a specified path are recorded. Then the optimum region where the piezoresistive resistors are placed is analyzed and the sensitivity of the chip is approximately calculated;(3) The method of anodic bonding is briefly introduced, and the impact on the sensor output whether the glass substrate packaged is analyzed. The change of the sensor output is investigated when respectively using different Young’s modulus and thickness of adhesive;(4) Stress isolation package method is presented. The diaphragm thickness, corrugated depth and quantity which are the major parameters of corrugated diaphragm are respectively simulated to analyze the influence on the sensor output by ABAQUS. The outputs of sensor are compared by experiment when packaging different parameters of corrugated diaphragm, and the optimal one is chosen;(5) The temperature drift curves of the stress isolated packaged sensor are presented by experiments and FEA respectively. Two kinds of structure are designed to improve the temperature drift of the sensor, finite element simulation results prove the feasibility of the structure.更多还原