Characterization of Intermetallic Compounds Formed during the Interfacial Reactions of Liquid Sn and Sn-58Bi Solders with Ni Substrates

Interfacial reaction between Sn-Bi alloy and Ni substrate

“…This indicates that the growth of Ni 3 Sn 4 is controlled by a diffusion mechanism, in agreement with the literature. [9][10][11][12][13][14] Moreover, the average thickness of Ni 3 Sn 4 decreases with increasing Bi content (see Fig. 3).…”

“…Chen et al 10 investigated the interfacial reaction between solid Sn-Bi eutectic alloy and Ni substrate at different temperatures for various reaction times. Recently, Young et al 11 reported the interfacial reaction for electroplated Ni and electroless Ni with Sn-Bi eutectic alloy annealing at 418 and 453 K. In their work, [9][10][11][12][13][14] only Ni 3 Sn 4 was found as a product of the interfacial reaction at each reaction temperature for various reaction times. This seems unreasonable, as two IMCs exist in the Ni-Bi binary system (NiBi and NiBi 3 ) and three (Ni 3 Sn, Ni 3 Sn 2, Ni 3 Sn 4 ) in the Ni-Sn binary system according to the Ni-Bi and Ni-Sn binary phase diagram.…”

“…Several studies [9][10][11][12][13][14] have reported on the interfacial reaction between Sn-Bi eutectic alloy and Ni substrate. Kang et al 9 studied the interfacial reaction between liquid Sn-Bi eutectic alloy and Ni substrate at 443 K for 20 min.…”

Intermetallic Reactions in Sn-0.4Co-0.7Cu Solder BGA Packages with an ENIG Surface Finish

“…The interfacial reactions between Sn-0.4Co-0.7Cu eutectic alloy and immersion Au/electroless Ni(P)/Cu substrates have also been analyzed by Sun et al 5 Both CoSn 2 and Cu 6 Sn 5 particles were found in the Sn-0.4Co-0.7Cu solder matrix, while only one ternary (Cu,Ni) 6 Sn 5 intermetallic compound appeared at the solder/pad interface. The Ni 3 Sn 4 intermetallic phase, as commonly reported in the literature [6][7][8] for the interfacial reactions between Sn-based solders and Ni substrates, was absent in the study of Sun et al 5 In order to clarify the intermetallic reactions in this ternary eutectic Sn-0.4Co-0.7Cu alloy system, the chemical composition and morphology of intermetallic compounds formed in the Sn-0.4Co-0.7 Cu solder matrix and at its joint interface with Au/Ni/Cu pads after reflowing and aging processes were analyzed. In addition, the growth of interfacial intermetallics was measured and its kinetics discussed.…”

Mechanisms for the intermetallic formation during the Sn-20In-2.8Ag/Ni soldering reactions

“…However, an overgrowth of such intermetallics will cause cracking along the interfaces. Nickel is one of the most popular substrate materials for soldering, so the solid/liquid reactions of Ni with certain commonly used solders (such as pure Sn, 7-9 pure In, 10 Sn-51In, 11,12 Sn-58Bi, 8 Sn-9Zn, 13 and Sn-37Pb 14 alloys) have been investigated. In this present study, the interfacial reactions between liquid Sn-20In-2.8Ag solder and Ni substrates take place at temperatures ranging from 225°C to 350°C for 15-90 min, with the aim that the mechanism of soldering reactions for this newly developed solder alloy be clarified.…”