Size effect on IMC growth induced by Cu concentration gradient and pinning of Ag3Sn particles during multiple reflows

作者：Ma, Haoran; Kunwar, Anil; Huang, Ru; Chen, Jun; Wang, Yunpeng; Zhao, Ning^*; Ma, Haitao^*

来源：Intermetallics, 2017, 90: 90-96.

DOI：10.1016/j.intermet.2017.06.013

• Intermetallics
• Diffusion
• Crystal growth Joining
• Interfaces Grain boundary

Size effect on growth kinetics of interfacial intermetallic compound (IMC), induced by Cu concentration gradient and pinning effect of Ag3Sn particles during multiple reflows, was investigated in this article. The simulation results, for Cu distributions in solder bulks of different volumes after a single reflow for 60 s at 250 degrees C, show that Cu concentration gradient in liquid increases with the growing size of solder bump. On the contrary, resistive pressure of nano particles decreases gradually with the increasing bump size. In conclusion, the pinning effect of Ag3Sn particles on IMC grains plays a dominant role in small samples, whereas the inhibiting effect of Cu concentration gradient is mainly functional in big samples. Combining the two factors, solder bump in an intermediate diameter of 800 mu m benefits most and has the largest IMC thickness during multiple reflows.

• 出版日期2017-11
• 单位大连理工大学