一种MEMS热电制冷器的设计

Design and Optimization of a Microelectromechanical System Thermoelectric Cooler

研究一种基于MEMS工艺的微型热电制冷器.采用薄膜热电材料减小器件的尺寸,采用微机械加工工艺形成的硅杯结构降低衬底的热泄漏.器件在材料和工艺上都与微电子工艺兼容,易于与电子器件集成.分别讨论了热电臂长度、厚度及绝缘膜厚度等结构参数对器件最大制冷温差、制冷系数、制冷功率等性能的影响,得出最优的设计参数.分析中考虑了绝缘层热泄漏,制冷区的热对流和热辐射,以及接触电阻等非理想因素.分析结果表明,器件工作时达到的最大温差为40K;冷端温度为290K时,制冷功率为3mW.

A microelectromechanical system(MEMS) thermoelectric cooler is designed to be built upon a Si rim to diminish the substrate's thermal bypass. The thermoelectric thermoelements were fabricated in Bi_2Te_3 films which have the high figure of merit at room temperature. Increased reduction in size makes the cooler smaller, and the fabrication of the MEMS cooler is made compatible with microelectronics fabrication processes, so that the cooler can be easily integrated with electronic devices. The length and thickness of thermoelectric elements are optimized for achieving maximum cooling performance of the cooler. Effects of substrate thermal bypass, convection and radiation heat loads and electrical contact resistances are taken into account in the calculation. As a result, the cooling power of a few milliwatts or a maximum temperature difference of 40 K can be achieved.