Fast penetration of Sn into Ag by diffusion induced recrystallization
Fast penetration of Sn into Ag by diffusion induced recrystallization
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DOI：
10.2320/matertrans.47.822
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发表时间：
2006-03
影响因子：
1.2
通讯作者：
T. Takenaka;M. Kajihara
中科院分区：
文献类型：
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作者：
T. Takenaka;M. Kajihara
在Ag基导体合金和Sn基焊料合金之间的互连处，由于在通常的退火条件下的固态加热期间的扩散诱导再结晶（退火），Sn快速渗透到导体合金中。与二元Ag-Sn化合物的形成一样，Sn的渗透使互连处的导电性劣化。为了考察Sn在导体合金中的渗透速率，本文对Ag（Sn）体系中Sn的渗透动力学进行了实验观察。实验是使用扩散连接技术制备的Sn/Ag/Sn扩散偶进行的。将扩散偶在具有硅油的油浴中在T1/4 433{473 K}的温度下等温退火不同时间，最高达t1/4 1100 h。由于退火，在T1/4 453和473 K下，由于退火，在Ag中形成与Sn合金化的区域。然而，在T/4 433 K时，不能清楚地识别出α区。Sn在Ag区的浓度约为Sn在Ag中溶解度的一半。在t 453 K时，相变区的平均厚度l达到4 mm，在t 473 K时，相变区的平均厚度l达到5 mm。利用数学模型对实验结果进行了理论分析。分析表明，在实验退火时间内，晶界区的生长受晶界区运动边界处的界面反应控制。然而，在较长的退火时间，界面反应不再是移动边界的迁移的瓶颈和晶界扩散跨越的晶界区域支配的生长的晶界区域。
At interconnection between a Ag-base conductor alloy and a Sn-base solder alloy, fast penetration of Sn into the conductor alloy occurs due to diffusion induced recrystallization (DIR) during solid-state heating under usual energization conditions. Like formation of binary Ag–Sn compounds, the penetration of Sn deteriorates the electrical conductivity at the interconnection. In order to examine the penetration rate of Sn into the conductor alloy, the kinetics of DIR in the Ag(Sn) system was experimentally observed in the present study. The experiment was carried out using Sn/Ag/Sn diffusion couples prepared by a diffusion bonding technique. The diffusion couples were isothermally annealed at temperatures of T ¼ 433{473 K for various times up to t ¼ 1100 h in an oil bath with silicone oil. Due to annealing, a region alloyed with Sn is formed in Ag due to DIR at T ¼ 453 and 473 K. At T ¼ 433 K, however, the DIR region could not be recognized clearly. The concentration of Sn in the DIR region is about half of the solubility of Sn in Ag. The mean thickness l of the DIR region reaches to 4 mm for t ¼ 1100 ha t T ¼ 453 K and 5 mm for t ¼ 890 ha tT ¼ 473 K. The experimental results were theoretically analyzed using mathematical models. The analysis indicates that the growth of the DIR region is controlled by the interface reaction at the moving boundary of the DIR region within the experimental annealing times. At longer annealing times, however, the interface reaction is no longer the bottleneck for migration of the moving boundary and the grain boundary diffusion across the DIR region governs the growth of the DIR region.