Interfacial Segregation of Bi during Current Stressing of Sn-Bi/Cu Solder Interconnect
Authors: Yang, Q.L.; Shang, J.K.
Source: Journal of Electronic Materials, Volume 34, Number 11, November 2005 , pp. 1363-1367(5)
Abstract:Effect of electromigration on the interfacial structure of solder interconnects was examined in a Sn-Bi/Cu interconnect system. At current densities above 104 A/cm2, Bi migrated along the direction of the electron flow in the solder alloy. A continuous Bi layer was found at the solder interface on the anode side, while a Sn-rich region formed at the cathode side of the electrical connection. The presence of the Bi layer inhibited further growth of Cu-Sn intermetallic phase at the interface by acting as a diffusion barrier to the reacting species.
Document Type: Regular paper
Publication date: 2005-11-01