Effect of Electrode Material on Joint Strength of Soldered Joints With Sn-Bi and Sn-Bi-Sb Lead-Free Solder Balls

Abstract

The aim of this study is to investigate the joint properties of Sn-58mass%Bi and Sn-57mass%Bi-0.5mass%Sb low-melting lead-free solder balls on the electroless Ni/Au and Ni/Pd/Au plated Cu electrodes fabricated with a lead-free plating solution. Compared with the conventional Ni plating solution containing lead, the soldered joints with Ni/Au and Ni/Pd/Au electrodes fabricated with the lead-free plating solution showed comparable joint properties. In the joints with Ni/Pd/Au electrodes, ball shear force increased when the Pd layer is dissolved into solder by multi reflows. In both joints with Ni/Au and Ni/Pd/Au electrodes, a part of the Ni layer was dissolved into solder and thus the (Ni,Cu)3Sn4 intermetallic compound layer formed at the joint interface. Ball shear force decreased upon aging due to the growth of the (Ni,Cu)3Sn4 layer at the joint interface.

Effect of Sb and Zn Addition on the Microstructures and Tensile Properties of Sn–Bi-Based Alloys

“…Finally, dog-bone-type specimens (Figure 1) were machined from the cylindrical Sn-40Bi-based alloy ingots for the tensile tests. enhance the mechanical properties and wettability of Pb-free solders for green electronic devices [16][17][18][19][20][21][22]. Takao et al [23], for instance, reported that Sn-Bi and Sn-Bi-Cu alloys exhibit superplasticity.…”

“…Recently, several research groups have focused on manufacturing new alloys doped with micro-/nanometer-sized particles, e.g., Ni, Fe, Zn, Ag, Al, ZrO 2 , Al 2 O 3 , TiO 2 , etc., to enhance the mechanical properties and wettability of Pb-free solders for green electronic devices [16][17][18][19][20][21][22]. Takao et al [23], for instance, reported that Sn-Bi and Sn-Bi-Cu alloys exhibit superplasticity.…”