Morphology and chemical composition of Cu/Sn/Cu and Cu(5 at-%Ni)/Sn/Cu(5 at-%Ni) interconnections

In the present paper, scanning and transmission electron microscopies as well as energy dispersive X-ray spectroscopy investigations were performed to describe the morphology and chemical composition of the intermetallic phases growing in Cu/Sn/Cu and Cu(Ni)/Sn/Cu(Ni) interconnections during the diffusion soldering process. The obtained results revealed that even a small amount of Ni addition (5 at-%) to the Cu substrate totally changes the morphology and the rate of formation of the intermetallic phase layers in the solder/substrate reaction zone of the interconnections prepared at the same time and joining temperature conditions. The presented studies are promising in terms of the shortening of the soldering time in the electronic industry.