Effect of Cu6Sn5 nanoparticles on the morphology and properties of SAC3005/Cu solder joints
This work aims to investigate the impact of Cu6Sn5 nanoparticles on the morphology and properties of intermetallic compounds(IMCs)in SAC3005 solder joints.Cu6Sn5 nanoparticles were synthesized using a wet chemical method and then added into the SAC3005 solder.The resulting composite solder joints,named as SAC3005-xCu6Sn5(x= 0%,0.12%,0.18%for mass fraction),were prepared through a reflow soldering process.Metallographic microscopy was used to characterize the cross-sections of the solder joints and detect the present of IMCs.Additionally,ANSYS finite element software was utilized to simulate the interface of IMCs and analyze the failure mechanism of solder joints on printed circuit board(PCB).The results indicate that the Cu6Sn5 nanoparticles in SAC3005/Cu solder joints leads to thinner intermetallic compound(IMCs)layers by comparing with the ones without nanoparticles.The presence of Cu6Sn5 nanoparticles inhibits the growth of IMCs during the reflow soldering process,thereby,to improve the reliability of the solder joints.Nanoparticles hinder the diffusion of Sn and Cu atoms at the interface,which prevent the growth of Cu6Sn5 IMCs.The optimal suppression was achieved at the addition of 0.12%mass fraction of Cu6Sn5 nanoparticles.The Cu6Sn5 and Cu3Sn layers experience stress and strain concentration at the solder joint interface,which is a weak point during the solder joint service life.