This study investigated the effects of the passage of electric currents of 500 A/cm~2 density through Sn/Ag couples annealed at 120 and 160 deg C. The results showed that when the direction of electron flow was from the Sn side to Ag, it enhanced the growth of the Ag_3Sn phase at the interface, and it retarded the Ag_3Sn phase growth when the electrons flowed from the Ag side to Sn. Similar results were found in the Sn/Ni system. The Ni_3Sn_4 phase formed in the Sn/Ni couples annealed at 160 and 180 deg C. The growth rate of the Ni_3Sn_4 phase increased when the electrons flowed from the Sn side to Ni side, and decreased if the direction of electron flow was reversed. The thickness of the reaction layers was measured, and the apparent effective charges Z_a* for Sn were determined. The values of Z_a* decreased with increasing temperatures, which indicated that the effect of electromigration on interfacial reactions became less significant at higher temperatures.
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