本實驗使用錫銀鉍銦無鉛銲錫在Si晶片U型溝槽中製作出銲料導線並研究其電遷移行為。兩極的銅導線首先以電鍍方式製備於溝槽中，將自行混合的實驗銲料84Sn3Ag3Bi10In(數字部分表示重量比)迴焊於電極中間完成實驗導線，電遷移實驗於不同溫度及電流密度等實驗條件下進行。添加Bi與In的84Sn3Ag3Bi10In銲錫液相線溫度降至203°C，而於相同對應溫度下比較84Sn3Ag3Bi10In與94Sn3Ag3Bi的失效時間，發現84Sn3Ag3Bi10In有較長的失效時間，本論文進而探討84Sn3Ag3Bi10In在電遷移效應下的反應機制。 在電極界面處會因為Cu原子溶入焊料而生成介金屬化合物Cu6(Sn,In)5，化合物的存在有助於銲錫凸塊與印刷電路板上的金屬墊層能夠更穩定的結合；銲料中出現Cu6(Sn,In)5及ζ-phase兩種介金屬化合物，ζ-phase為Ag4Sn 與Ag3In之固溶相。利用EPMA分析導線中介金屬化合物微量的成分變化，並估算其自由能以討論電遷移效應對銲料微結構之影響。結果顯示，ζ-phase的形成在電遷移失效機制中扮演很重要的角色。 Pb-free SnAgBiIn solder lines were prepared in Si(001) U-grooves to investigate the behaviors under electromigration. Cu electrodes were electroplated in the grooves and the solders were consequently reflowed between the electrodes. The samples were tested under various temperatures and current densities. The addition of indium and bismuth could decrease the melting point of 84Sn3Ag3Bi10In to 203°C, Average failure time was compared for 84Sn3Ag3Bi10In and 89Sn3Ag3Bi at the same homologous temperature. The results show that the 84Sn3Ag3Bi10In has longer life time than 89Sn3Ag3Bi. Therefore, we will discuss the mechanism of microstructure evolution 84Sn3Ag3Bi10In under electromigration effect. The intermetallic compound formed between the solders and Cu electrodes are Cu6(Sn,In)5, and those formed inside the solder had the composition of ζ-phase, which is the solid solution of Ag4Sn and Ag3In. The exact composition of the compounds under current was identified by EPMA. Gibbs free energies of the formation of compounds were calculated to discuss the variations of microstructure by current. The results suggested that the existence of ζ-phase plays an important role under electromigration.
