(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院， 長沙 410083;
2. 中南大學(xué) 粉末冶金國家重點實驗室， 長沙 410083)
摘 要: 焊料與基體的界面反應(yīng)對高性能電子材料焊接接頭的力學(xué)性能和可靠性都有著很重要的影響。 把焊接過程分為界面反應(yīng)和剩余焊料凝固兩個過程進(jìn)行討論，在相圖熱力學(xué)的基礎(chǔ)上， 通過計算亞穩(wěn)相圖、 比較界面處局部平衡時各相形成驅(qū)動力大小， 預(yù)測了Sn-3.5%Ag/Cu、 Sn-25%Ag/Cu和Sn-3.5%Ag/Ni擴(kuò)散偶界面反應(yīng)過程中的中間相形成序列； 同時利用Scheil-Gulliver凝固模型模擬了Sn-25%Ag/Cu體系中過剩焊料的非平衡凝固過程， 預(yù)測了焊料在隨后冷卻過程中的相演變信息。計算預(yù)測的結(jié)果與前人的實驗結(jié)果吻合很好。
關(guān)鍵字: 無鉛焊料；界面反應(yīng)； 反應(yīng)通道； 相圖計算； 中間化合物
of electronic materials
（1. School of Materials Science and Engineering,
Central South University, Changsha 410083, China;
2. State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract:It is believed that reaction products in the interface between solder and substrate have great effects on mechanical properties and reliability of the solder/substrate joint. Based on the calculations of metastable phase equilibria between the solder and the substrate and the comparison of the driving forces of formation of individual intermetallic compounds, a thermodynamics method was used to predict the formation sequence of the intermetallic compounds during the interfacial reaction period. This method was applied to the interfacial reaction of Sn-3.5%Ag/Cu, Sn-25%Ag/Cu, and Sn-3.5%Ag/Ni solder/substrate systems. In addition, by using Scheil-Gulliver model, the non-equilibrium solidification of Sn-25%Ag/Cu system was modeled and the microstructure evolution was also predicted. The results from thermodynamic calculations are in good agreement with previously reported experiments.
Key words: lead-free solder; interfacial reaction; reaction path; CALPHAD technique; intermetallics
