研究錫銦與銅界面之介金屬生長機制

由於歐盟實施了危害物質限用指令(RoHS , Restriction of Hazardous Substance)，限制有鉛銲料的使用，使得發展無鉛銲料成為重要課題，但隨著銲料組成的改變，製程溫度因熔點提高而增加，會導致因溫度提高而引發的缺陷，如翹曲、元件損傷等。低溫銲料的使用可有效改善此問題，本實驗使用Sn52In無鉛銲料，除了具低熔點的優點外，還有良好濕潤性、延展性，以及更長的疲勞壽命等。探討Sn52In銲料與Cu基板在140 C下進行反應2分鐘，之後進行固態長時效熱處理，觀察介金屬相轉變與生長動力學分析，相關文獻焊接溫度在180 oC左右，本實驗使用低溫140 oC接合溫度，以研究在此低溫接合下，其顯微結構演變。在固液反應下，發現介金屬Cu6(Sn , In)5的生成，若放置在室溫一段時間會生成介金屬Cu(In , Sn)2。而在固態時效熱處理下，發現介金屬Cu6(Sn , In)5以及Cu(In , Sn)2生長於界面。利用奈米壓痕儀器分析介金屬的機械性質，觀察介金屬Cu6(Sn , In)5的硬度與楊氏模數皆與Cu6Sn5無異。最後研究介金屬的生長動力學，將不同溫度與不同反應時間之介金屬厚度對時間作圖，並與文獻進行比較。

關鍵字

低溫銲料；錫銦銲料；奈米壓痕；活化能

並列摘要

The European Union carried out the Restriction of Hazardous Substances (RoSH), lead-free solders have displaced lead-bearing solders owing to the risk of toxic lead. Because of the change of the solder composition, the process temperature increased, which would lead to some defects, such as warpage and component failure. The low-temperature solders can solve the problems of thermal effect. This study was conducted to investigate the interfacial microstructures between Sn52In and Cu after solid-liquid and solid-solid reactions. Sn52In solder is a potential candidate for lead-free solder due to its low melting point, good wettability, good ductility and longer fatigue life. Cu6(Sn, In)5 was formed at interface after the reaction at 140 oC for 2 min. Besides, Cu(In, Sn)2 was formed after room temperature storage. It is of outmost important to carried out the storage of In-based solders. Cu6(Sn, In)5 and Cu(In, Sn)2 were found after aging at 60 oC to 110 oC for different reaction time. The mechanical properties of the hardness and Young's modulus of Cu6(Sn, In)5 were measured by nanoindenter. No significant difference between Cu6(Sn,In)5 and Cu6Sn5 on mechanical properties. Based the aforementioned results, the growth mechanism of the intermetallic compounds was discussed at the end of this study.