- 學位論文
薄膜熱電致冷元件之熱傳及熱應力分析
The Analysis of the Heat Transfer and Thermal Stresses in Thermoelectric Cooler
摘要
熱應力攸關薄膜熱電致冷元件的製作成敗。本文內容主要在建立一個簡易一維薄膜熱電元件通用之分析模型，並且和二維ANSYS薄膜熱電元件的熱應力分析比較。從分析中得知，一維分析在分布趨勢上可以和二維分析相似，但因為少考慮了z方向位移，故在應力值會小許多，且無法察覺出接腳處的應力。 此外，一般在熱電之相關書籍或論文中常會忽略湯姆生效應，而本文將其納入討論之中，目的在於能更廣泛的分析熱電元件的溫度及應力分布。由理論分析結果中發現湯姆生係數之值愈大，對於致冷能力之效果提升愈顯著，但是熱電元件所承受的正向應力也越大，層與層之間的剪應力也越大。此部份之結果可作為熱電材料發展之參考方向。而一維分析僅能提供一個初步的估算；若接腳問題能另有可靠製程解決，則一維分析也不失為一個快速提供有效數據的方法。
並列摘要
The thermal stress is a critical issue to the success of a thin-film thermoelectric cooler. The main purpose of this thesis is to establish a simple 1-D model for a thermal stress analysis of a thin-film thermoelectric element. Numerical computations in use of the software ANSYS are also performed for a comparison. This study shows that 1-D results share similar trends to those observed from computations, but the stress magnitudes are smaller. The reason is because in 1-D analysis, the potential effect on the stresses of the Z-direction displacement is ignored. Moreover, junction stresses can not be correctly captured in the 1-D model. Furthermore, Thomson effect is also taken into consideration while it is usually ignored in the literatures. Taking advantage of this effect, a better cooling ability can be attained, although also resulted are bigger thermal stresses. This 1-D model can thus offer a primary estimation for the design of novel thermoelectric cooler without deep consideration of junction stress.