【作者】 张绪瑞；

【导师】 胡明；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2007， 硕士

【摘要】 近几年来,随着微电子机械系统(MEMS)的发展,多孔硅优良的机械性能和热学性能逐渐为人们所关注。本文主要针对多孔硅材料在MEMS微热传感器中作为绝热层的应用进行了研究及模拟。本论文以多孔硅基热电偶式MEMS微热传感器为研究对象,研究了传热学、薄膜传热、有限元以及热电偶等基础理论知识;实验测量了在不同多孔硅基底上沉积金属薄膜电阻条的功率—温度曲线,进而对比验证多孔硅的绝热性能,为微传感器制作做好准备;用ANSYS软件进行建模来模拟多孔硅绝热性能验证实验,模拟中采用实验和数值计算结合的方法对有限元分析的载荷进行确定,结果表明所建立的有限元模型以及参数(特别是热生成率载荷大小)取值比较合理,模拟结果与实验相符合。实验提出热电偶式微热传感器模型,按照一定的工艺步骤完成传感器雏形,并通过给热端电阻条通电流加热的方式代替温度场,对热电偶的冷热端温差进行测量说明了传感器的可行性;利用ANSYS软件建立有限元模型,采用平面、三维直接、拉伸法以及壳单元等方法尝试建模,分别模拟电阻自加热和热端施加恒定温度场两种情况下热电偶式微热传感器的温度分布,特别是冷热端温度分布进行模拟,与实验值对比接近;最后以增加温差为目的,对多孔硅基热电偶式微热传感器进行了热学设计,得出扩大温差的要素和最终设计方案。模拟出最终设计的方案冷热端温差效果,给热端施加恒定100℃温度场,热电偶冷热端温差可达12℃左右,而瞬态分析结果在最初的12秒内温差可达30℃。更多还原

【Abstract】 Recently, with the development of Micro-Electro-Mechanical System (MEMS) technology, porous silicon (PS) has got more and more attention due to its excellent mechanical and thermal isolation properties. In this paper, the application of PS as thermal isolation layer in MEMS micro thermal sensor is studied and simulated.A PS-based thermocouple micro thermal sensor was present in this paper. Theories about heat transfer, thermal conduct of film, finite element and thermocouple were studied first. An experiment was designed to testify thermal insulation property of PS that to deposit metal film like Pt on PS layer and get its power consume-temperature curves. The experiment which made a good preparation for micro sensor was simulated by ANSYS finite element analysis (FEA) software. The Loads of FEA were gotten by experiments and numerical calculation. The results of the simulations were close to the experiment because of the right FEA model and appropriate value of parameters (especially heat generation rate).A thermocouple micro thermal sensor was advanced, and the rudiment sensor was finished according to a certain experiment steps. Then the temperature of hot and cold ends was measured to test the feasibility of the sensor, and the heat of the hot end was gotten by electrified metal resistance instead of exposing to heat filed. The FEA models were built by using the method of plane, 3-dimension, volume offset and shell elements. Temperature distribution of the thermocouple micro thermal sensor was simulated by those methods. Heat generation and constant temperature field were respectively loaded on the hot end of the sensor in the simulation and the temperature of the cold end was close to the experiment data. Finally, the work of thermal design for PS-based thermocouple micro temperature sensor was carried out with the purpose of increasing the difference in temperature between hot and cold ends. The difference in temperature of final project was simulated by FEA static thermal analysis. 12℃temperature difference between hot and cold ends could be gotten when a constant temperature field of 100℃was loaded on hot end, while 30℃temperature difference in the first 12 seconds by using transient analysis.更多还原