電化學沉積技術應用於微型熱電致冷器之研製

Abstract

隨著電子及光電元件產品封裝縮小化及高發熱密度的趨勢，高效率的冷卻及精確控溫技術越來越重要。微熱電元件具有體積小、無污染、控溫效率高等優點，正好符合此一趨勢。由於微電子及微機電技術的進步，使得熱電元件的設計及製程技術而有了新的發展及應用，而微小化的熱電元件更適合應用於微小的電子元件散熱，延長使用壽命及提高元件穩定度。 本研究利用電化學沉積的技術，電鍍n-type熱電材料Bi2Te3及p-type熱電材料Sb2Te3的合金電鍍，研製微型熱電致冷晶片，並探討不同金屬基板上其熱電材料的表面形貌，並找出較佳的電鍍參數，以比較在各個參數不同的情形下之改變，可達到材料之最佳匹配。利用黃光微影的製程分別將上下金屬電極及p-type及n-type腳位做連結，以完成製程整合。 本實驗以濃度為7.5 × 10-3 M 的Bi2O3與10 ×10-3 M 的TeO2，成功鍍出了緻密性良好的n-type Bi2Te3熱電材料，其鍍率約為6 um/hr，其成分為Bi約為45 %，Te成分約為55 %，故後續將再調變濃度，期望達到Bi 40 %及Te 60 %p-type Sb2Te3熱電材料已接近材料所需之成分比率，Sb成分約為42 %，Te成分約為58 %，但對於其表面粗操度仍需進ㄧ步的改善。 而由實驗結果做一實際運作，並對微熱電製冷晶片做特性量測，包括了XRD、SEM、Seebeck 係數、熱傳導係數以及電阻值的量測。With the electronic and optoelectronic components products and packaging technology grow up, and high fever of electronic products, high-efficiency cooling and precise temperature control technology is increasingly important. Micro thermoelectric element is small, clean, efficient, high temperature control device. By using its cooling application, we use costless electrochemical technique to fabricate micro thermoelectric cooler, in order to solution thermal problem of electronic products. We use Bi2O3, Sb2O3 and TeO2 metal oxide powder dissolve in diluted HNO3 for preparing electrolyte. And, we use different metal based plate to electroplate thermoelectric materials, in order to find better based for electroplating n-type junction Bi2Te3 and p-type junction Sb2Te3. We find a better electroplating conditions to electroplate Bi2Te3 material.The concentration of the metal powder choose 7.5 × 10-3 M Bi2O3 and 10 × 10-3 M TeO2 to electroplate a smooth morphology junction, and the composition of Bi near 45 % and Te 55 %, the growth rate is about 6 um/hr. The other thermoelectric material Sb2Te3 can be found that the composition of Sb is neat 42 ％, and Te 58 ％, it is very close the proportional composition. But, the smoothness of Sb2Te3 is needed to be improve.