新型LED晶片接合無鉛銲料開發

本研究探討新型BiAg系晶片接合銲料性質，調查其與Cu基材間介面型貌，並進行銲點拉伸性質測試。實驗結果顯示Bi11wt%Ag合金電阻率86.5µΩ-cm，較共晶組成銲料（Bi-2.5wt%Ag, 116.5 µΩ-cm）改善許多。此外，Bi11wt%Ag合金與Cu基材潤濕性亦較佳，銲點強度與Pb-5Sn相彷，具取代現有Pb-5Sn及Au-Sn銲料潛力。

This study investigated the properties of a new Pb-free die-attach solder system, Bi-Ag alloys, as well as the interfacial morphology and tensile behavior of the Bi-Ag/Cu joints. The results show that the electrical resistivity of the Bi-11wt%Ag alloy was 86.5 µΩ-cm, which is much lower that that of the Bi-2.5wt%Ag eutectic specimen, 116.5 µΩ-cm. Also, the Bi-11wt%Ag alloy showed a fair wettability to the Cu substrate and comparable joint tensile strength to commercial Pb-5Sn solder Thus it has the potential to be the replacement for the present LED die attach solders, Pb-5Sn and Au-20Sn alloys.