Phase reaction in Sn-9Zn solder with Ni/Au surface finish bond-pad at 175°C ageing
Phase reaction in Sn-9Zn solder with Ni/Au surface finish bond-pad at 175°C ageing
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DOI：
10.1016/j.jallcom.2006.01.106
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发表时间：
2007-01-31
影响因子：
6.2
通讯作者：
Hsieh, Ker-Chang
中科院分区：
文献类型：
--
作者：
Chang, Shih- Chang;Lin, Sheng-Chih;Hsieh, Ker-Chang
γ-Au 3 Zn 7和γ（2）-AuZn 3在回流焊后的焊料中形成带状相。在175 ℃时效期间，γ和γ（2）转变为γ（3）-AuZn 4，最后（Zn）相沉淀出ε-AuZn 8。Ni 5 Zn 21形成于焊盘界面。时效一定时间后，在金属间化合物（IMC）区附近出现无Zn区。Ni可通过无（Zn）区扩散并与Au-Zn IMC反应形成新的（Ni，Au）Zn-4三元相。剩余的γ（3）-AuZn 4相向富Au相转变，形成γ（2）-AuZn 3相，然后形成γ-Au 3 Zn 7相。根据本研究结果，回流共晶（Zn）相的存在是维持Sn-Zn钎料中不同相平衡的关键因素。(c)2006 Elsevier B. V.保留所有权利。
gamma-Au3Zn7 and gamma(2)-AuZn3 formed as band-shaped phases in solder after reflow process. During 175 degrees C ageing, gamma and gamma(2) transformed to gamma(3)-AuZn4 and finally (Zn) phase precipitated out next to epsilon-AuZn8. Ni5Zn21 formed in the bond-pad interface. There were (Zn)-free zones near intermetallic compound (IMC) regions after certain ageing period. Ni could diffuse through the (Zn)-free zone and react with Au-Zn IMC and formed a new (Ni, Au)Zn-4 ternary phase. The rest part of Au-Zn IMC such as gamma(3)-AuZn4 transferred toward Au-rich IMC as gamma(2)-AuZn3 and then gamma-Au3Zn7 phase. According to the results of this study, the existence of reflowed eutectic (Zn) phase is the key factor to maintain the different phase equilibrium in the Sn-Zn solder. (c) 2006 Elsevier B.V. All rights reserved.