Kinetics of reactive diffusion between Au and Sn during annealing at solid-state temperatures
Kinetics of reactive diffusion between Au and Sn during annealing at solid-state temperatures
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DOI：
10.1016/j.msea.2004.08.053
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发表时间：
2005-01
期刊：
影响因子：
6.4
通讯作者：
T. Yamada;K. Miura;M. Kajihara;N. Kurokawa;K. Sakamoto
中科院分区：
文献类型：
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作者：
T. Yamada;K. Miura;M. Kajihara;N. Kurokawa;K. Sakamoto
采用扩散连接技术制备了锡/金/锡扩散偶，在固相温度下研究了金和锡之间的反应扩散。扩散偶在T=393和473K的温度下，在硅油油浴中进行不同时间的热处理。热处理后，在Au/Sn界面上形成了由AuSn4、AuSn2和AuSn3组成的化合物层。在T=393K和473K时，AuSn4层的厚度分别是AuSn2层和AuSn层的6倍和4倍。化合物层的厚度之比保持恒定，与退火时间无关。化合物层的总厚度L由方程L=k(t/t0)n描述为热处理时间t的函数，其中t0为单位时间，1s。在T=393K时，指数n几乎等于1/2，但在T=473K时，指数n的值在1/4和1/2之间。在T=473K时，n的中间值表明晶界扩散对反应扩散有贡献，并且以一定的速率生长。随着退火温度的降低，晶界扩散的贡献将变得更加显著，但晶粒长大的速度会变慢。因此，在T=393K时，n变得接近1/2。根据厚度比的恒定，得出在恒定的退火温度下，AuSn4、AuSn2和AuSn3层的速率控制过程是相同的。
The reactive diffusion between Au and Sn was experimentally studied at solid-state temperatures using Sn/Au/Sn diffusion couples prepared by a diffusion bonding technique. The diffusion couples were annealed at temperatures of T=393 and 473K for various times in an oil bath with silicone oil. After annealing, compound layers composed of AuSn4, AuSn2and AuSn were recognized to form at the Au/Sn interface. The thickness of the AuSn4layer is about six and four times greater than those of the AuSn2and AuSn layers at T=393 and 473K, respectively. The ratio of the thicknesses of the compound layers is kept constant independently of the annealing time. The total thickness l of the compound layers is described as a function of the annealing time t by the equation l=k(t/t0)n, where t0is unit time, 1s. The exponent n is nearly equal to 1/2 at T=393K but takes a value between 1/4 and 1/2 at T=473K. Such an intermediate value of n at T=473K indicates that the grain boundary diffusion contributes to the reactive diffusion and the grain growth occurs at certain rates. As the annealing temperature decreases, the contribution of the grain boundary diffusion should become more remarkable, but the grain growth will slow down. Consequently, n becomes close to 1/2 at T=393K. According to the constancy of the ratio of the thicknesses, it is concluded that the same rate-controlling process works in the AuSn4, AuSn2and AuSn layers at a constant annealing temperature.