鋁線由於價格低廉，在過去一直是打線接合的應用線材。鋁線在接合過程中是與鋁膜進行接合，因此其優勢在於不會有介金屬化合物的問題發生，但由於易氧化、高電阻率及低延性，故主要應用於產品附加價值較低的產品。另外，鋁線因為低潤濕性而無法於放電成球過程中形成置中正圓球，而以楔型接合應用，侷限了在封裝產業的發展。本研究使用高強度的20 μm Al-0.5Si合金線為芯線，並鍍上約80及250奈米鋅層形成鍍鋅精細鋁矽線(ZAS80及ZAS250)，以幫助鋁線放電成球。
鋁線表面容易產生高熔點的氧化鋁而不利線材之尾端熔融成球，而熔融鋅具有跟氧化合較低的自由能，因此可降低成球時氧化鋁含量而順利成球。成球外觀方面，藉由比較不同厚度的鋅層，可觀察到ZAS80結球外觀為正圓，從剖面特徵可發現球內部有微氣孔生成。當鋅層厚度提升至250 nm，因反應時間增加，內部氣孔消失，但同時因氧化還原反應激烈，致使球部外觀粗糙。此外，本研究以電子微探儀調查球部與線材元素分佈，發現球部與熱影響區皆不易偵測到鋅，直至距球部中心約100 μm處才能明顯偵測鋅訊號，主要理由是而放電結球過程溫度遠高於鋅沸點，所以球部與熱影響區部位的鋅容易氣化揮發而導致不易偵測其訊號。
透過通電試驗與拉伸測試，顯示當電流愈接近線材熔斷值時，較厚的鋅鍍層ZAS250會有劣化現象，導致無論在電性表現亦或機械性質上皆有明顯衰退，而ZAS80與原材則呈現良好的應用特性。
在第一銲點拉伸測試中，不同鋅層厚度之鋁矽線皆具有良好接合強度，即使ZAS80球內有微氣孔亦不影響接合特性。將第一銲點進行長時間通電試驗後，ZAS80仍有符合標準之強度，顯示其有良好接合性。此外，在試驗前後界面處皆無觀察到IMC生成，因此能減低對接合可靠度的影響。針對打線接合迴路之電性調查，ZAS80迴路電阻低且熔斷電流高。
就第二銲點經熱時效及硫化試驗處理後的表面形貌進行分析，熱時效後原材及ZAS80仍表現良好的接合性；而根據長時間硫化後結果顯示，鍍鋅層也具備抵抗硫的能力。綜觀上述實驗結果，ZAS80為具放電成球性且有較佳電性及可靠度穩定之新型鍍層鋁線材，極具封裝應用潛力。

Aluminum wire is the common material of the wire bonding due to its resistance to oxidation and low price. It does not melt when becoming a free air ball (FAB) during the electronic flame-off (EFO) process with wettability, and is applied by wedge bonding. This study used 20 μm(0.8 mil) Zn-Coated Al-0.5wt.%Si (ZAS) wires to improve the shape of the FAB after the EFO process, while maintaining stability of the mechanical properties, such as the interface bonding strength and hardness. In order to test circuit stability after wire bonding, the current test was performed. During the experiment, it was found that 80 nm ZAS with wire bonding has lower resistance and higher fusing current. To verify the first bond reliability of ZAS80, the bonded samples with different fusing current were tested for 24 hours. The results showed that it still had good bond strength and there were no IMCs at the bonding interface. Besides, 175℃ aging and sulfide tests were used to understand the second bond reliability. It indicated that AS and ZAS80 would not be affected by the heat and sulfur. Accordingly, ZAS80 could be a promising candidate for wire bonding in the future.

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