高溫銲錫的應用已擴展到汽車、航空、電力半導體封裝等領域。高鋅含量的錫鋅合金可作為一種很好的高溫無鉛銲料，但高含量的鋅會導致低潤濕性。本研究選取Cu和Ti作為合金元素，用於改善Zn- 25Sn銲料合金的潤濕性，並深討Zn-25Sn-x(0.1-0.3)Cu-(0.01-0.03)Ti合金與Cu基板之間的潤濕性和金屬間化合物的形成行為。本實驗使用潤濕天平 (Wetting balance) 在銅基板上塗佈助焊劑，實驗溫度為高於Zn-25Sn銲料的熔點溫度的 40°C。實驗結果顯示，添加Ti和Cu降低潤濕時間和提升潤濕力。本實驗添加量的銅添加量太多不會增加銲料合金的潤濕性，然而鈦的連續添加會待續增Zn-25Sn-xCu-yTi的潤濕性。潤濕反應在銲料/Cu界面形成CuZn5和Cu5Zn8 IMC，反應產物以Cu5Zn8 IMC層為主。元素分佈分析指出Ti趨向於在銲料表層和界面層中積累，從而降低了銲料合金與基材之間的表面張力；Cu和Ti的結合也增加了IMC層的厚度，降低了Zn-25Sn系統中Cu5Zn8IMC形成的活化能。

The Zn-Sn solder of high Zn content could be a great alternative high temperature Pb-free solder. But high content of Zn may give rise to poor wettability. Cu and Ti were selected in this study as alloying elements for improving the wettability of Zn-25Sn solder alloys. The present study investigated the wetting behavior and intermetallic compound formation behavior between Zn-25Sn-x(0.1-0.3)Cu-(0.01-0.03)Ti solder alloys and Cu substrate. The wetting behavior were investigated using wetting balance at Cu substrate with flux at a temperature ~40°C above the liquidus temperature of the Zn-25Sn solder. The results indicate that a combination addition of Ti and Cu improves the performance in terms of wetting time and wetting force. Higher addition of Cu in the concentration range investigated did not further enhance the wettability of solder alloy. On the other hand, continuous addition of Ti improves the wettability of Zn-25Sn-xCu-yTi. The wetting interaction formed CuZn5 and Cu5Zn8 IMCs at the solder/Cu interface, with Cu5Zn8 as the dominant IMC layer. The elemental distribution analysis pointed out Ti tends to accumulate at the solder surface layer and in the interfacial layer. The adsorption of Ti lowers tension between the solder alloy and the substrate. The combination of Cu and Ti also increaseas the thickness of IMC layer and decreasing the activation energy of Cu5Zn8 IMC formation in the Zn-25Sn system.

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