【作者】 张五金；

【导师】 金仁成；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2008， 硕士

【摘要】 随着微机械加工技术和MEMS技术的快速发展,微型化成为传感器发展的重要方向。采用与标准IC工艺相兼容技术制作而成的微热板式微气压传感器由于具有体积小、功耗低、量程宽、热响应快等优点,已成为国内外MEMS领域的重要研究方向。本文主要从理论分析、结构优化、以及性能测试等方面对微热板式微气压传感器进行了研究。主要包括以下内容:用经典传热理论和稀薄气体动力学对微热板式微气压传感器进行了电热理论分析并建立了传感器电热理论分析模型;采用有限元分析软件CoventorWare对三种薄膜厚度分布不同的微热板进行了热力分析,仿真结果表明,微热板结构层薄膜厚度分布的不同会影响微热板的变形方向;之后,结合微热板传热理论分析与热力有限元模拟建立了微热板式微气压传感器电热力耦合分析理论模型;采用MATLAB软件对理论模型计算求解,研究分析了微气压传感器在恒流、恒温工作模式下微热板的热变形对传感器耦合信号输出的影响。介绍了微热板式微气压传感器设计中的关键问题,采用ANSYS软件对悬浮微热板的三种不同支撑方式作了分析比较。仿真结果表明,环形支撑结构微热板不仅固体热损耗小,而且能够有效缓解薄膜材料膨胀引起的热变形。针对传感器动态性能测试的要求,完善了测控系统气压自动控制算法,设计了一种参数在线自调整模糊控制器,并实现气压自动控制。实验结果表明,该控制器具有动态响应快,稳态误差小的特点,在整个气压范围内能够获得较好的控制效果。另外,开展了微热板式微气压传感器的测试研究,测试了传感器在恒电流、恒电压和恒温三种工作模式下的响应特性。测试结果表明,恒电流与恒电压工作模式下,在10～5×10~4Pa气压范围内传感器较灵敏,但气压更高时由于工作温度太低,传感器灵敏度很低,在10～10~5Pa气压范围内传感器输出电压摆幅仅为几百毫伏;恒温工作模式下传感器输出电压随气压增加而增加,输出摆幅达到几伏,在10～10~5Pa范围内都有较高灵敏度。此外,从多次测试过程响应曲线的变化情况可以看出,传感器的重复性比较好,稳定性比较高。更多还原

【Abstract】 As the rapid development of microelectronic and micromachining technology, micromation has become an important development direction of a sensor. As micro gas pressure sensor based on micro-hotplate (MHP) fabricated using the technology compatible with standard IC process has less volume, lower power, wider range, and more fast thermal response, etc, so it has become an important research direction in MEMS field at home and abroad. This paper mainly researched MHP-based micro pressure sensor from theory analysis, structure optimization, and performance test. The main contents as follows:Electro-thermal theoretical analysis of the sensor is conducted using classical heat transfer theory and rarefied gas dynamics, and electro-thermal theoretical analysis model is built; Thermal-mechanical analysis of the MHP with different thickness distributions of thin films is conducted using finite element analysis software CoventorWare. The simulated results show that the MHP thermal deformation direction is related with thickness distributions of thin films. Then, combining the MHP electro-thermal theoretical analysis and thermal-mechanical finite element modeling, coupled electro-thermal-mechanical theoretical analysis model of sensor is built. The theory model is solved using MATLAB, and studying the MHP thermal deformation effect on the coupled signal output of sensor at constant current condition and constant temperature condition respectively.The key problems in MHP-based micro gas pressure sensor design are introduced, three different support styles of suspended MHP are analyzed and compared using ANSYS software. The simulated results show that circular support structure MHP not only has little solid heat loss, but also can release thermal deformation induced by the expansion of thin films.Aiming at the requirement of the sensor dynamic performance test, perfect pressure automatic control algorithm of the measurement and control system, and design a fuzzy controller of online adjusting parameters to realize gas pressure automatic control. The experiment results show that the controller has characteristics of fast dynamic response and small error, and can acquire better control result over the entire pressure range. Furthermore, the MHP-based micro gas pressure sensor test research is also developed, and test the sensor response characteristic at the conditions of constant current, constant voltage and constant temperature. The test results show that for constant current and constant voltage operating mode, the sensor is apparently sensitive in the pressure range of 10～5×10~4Pa, while the sensitivity falls down at higher gas pressure due to too low working temperature, and the output voltage amplitude is only a few hundreds of millivolts from 10 Pa to 10~5Pa. For constant temperature mode, the sensor output voltage increases if elevating gas pressure, and higher sensitivity appears in the pressure range of 10～10~5Pa so that the output voltage amplitude is about a few volts. In addition, from many times test process, the sensor has good repeatability and stability.更多还原