Impact Properties of Sn-0.75Cu Lead-Free Solder Ball Joint
Impact properties of a solder ball joint with a Sn-0.75mass%Cu lead-free solder were investigated under aging conditions at 393 K. Moreover, obtained impact properties were compared with those of the joints with Sn-3.5mass%Ag and Sn-3.5mass%Ag-0.5mass%Cu solders. Ball impact force of a Sn-0.75Cu joint was stable at 4.5~5 N, which is similar to that of a Sn-3.5Ag-0.5Cu joint without aging, upon aging at 393 K for 1000 h. In the Sn-0.75Cu joint without aging, main fracture mode was complex fracture of the solder and an intermetallic compound (IMC) formed in a joint interface. Main fracture mode changed from the complex mode to solder fracture upon aging, and thus the impact toughness improved.
H.S. Lee, I.S. Yoon and M.H. Aliabadi
I. Shohji et al., "Impact Properties of Sn-0.75Cu Lead-Free Solder Ball Joint", Key Engineering Materials, Vols. 385-387, pp. 745-748, 2008