Interfacial Reactions of Sn-58Bi and Sn-9Zn Lead-Free Solders with Au/Ni/SUS304 Multilayer Substrate

Abstract

The liquid/solid interfacial reactions of Sn-58Bi (SB) and Sn-9Zn (SZ) lead-free solders with Au/Ni/SUS304 multilayer substrates have been investigated in this study. In the SB/Au/Ni/SUS304 couple, only the Ni 3 Sn 4 phase with needle-like grains was formed at the SB/Au/Ni/SUS304 interface. The Ni 5 Zn 21 phase with a column structure was formed at the SZ/Au/Ni/SUS304 interface. The thickness of both intermetallic compounds (IMCs) increased with increasing reaction temperature and time. Meanwhile, the growth mechanism of these two IMCs is seen to follow a parabolic law and is diffusion controlled.

Kinetic analysis of Ni5Zn21 growth at the interface between Sn–Zn solders and Ni

“…The prefactor and apparent activation energy were determined to be 7.3 Â 10 À3 m s À1 and 8.4 Â 10 À11 m 2 s À1 , and 70.4 kJ/mol and 47.2 kJ/mol for chemical reaction and diffusion, respectively. Compared the previous studies [10,14], the activation energy for diffusion presented in this work was relatively smaller. Chan et al [10] reported the activation energy to be 68.9 kJ/mol.…”

“…Chan et al [10] reported the activation energy to be 68.9 kJ/mol. Recently, Yen and his coworkers [14] studied the interfacial reactions of Sn-9wt%Zn solders with Au/Ni/SUS304 substrate and they determined the activation energy for Ni 5 Zn 21 growth to be 92.6 kJ/mol. In addition, the corresponding results were summarized in Table 4(a) and (b).…”

“…However, only a few studies associated with Ni 5 Zn 21 growth kinetics have been reported. Chan et al [10] reported that Ni 5 Zn 21 growth is diffusion-controlled at the liquid/solid Sn-9wt%Zn/Ni interface at temperatures ranging from 250 C to 350 C for 1 h to 4 h. Yen et al [14] studied the interfacial reactions of Sn-9wt%Zn with Au/Ni(1.6 mm)/SUS304 at 240 Ce270 C. They also observed that the interfacial reactions are governed by diffusion mechanism. Zhu et al [15] studied the solid/ solid interfacial reactions between Ni and SneZn solders (Sn-8at% Zn, Sn-35at%Zn and Sn-60at%Zn) at 190 C for various durations from 480 h to 1200 h. Similarly, the Ni 5 Zn 21 growth results implied that the mechanism is diffusion-controlled.…”

Interfacial reactions of Pb-free solders with Au/Pd/Ni/brass multilayer substrates

“…An Au/Pd/Ni multilayer structure is commonly electroplated onto a metallic substrate surface to improve the joint reliability and wettability between the solder and substrate. Numerous studies have reported on the interfacial reactions of Pb-free solders with Au/Pd/Ni/metallic substrates [14][15][16][17][18][19][20][21][22][23][24][25][26]. However, research on the interfacial reactions between the solder and Au/Pd/Ni/brass systems is lacking.…”

Effects of Minor Amounts of Zn on the Sn-Zn/Ni Interfacial Reactions and Phase Equilibria of the Ternary Sn-Zn-Ni System at 250°C

“…10,19,20 In our previous study, 10 the effects of Zn content (1 wt.% to 9 wt.%) in Sn-Zn solders were investigated at the Ni interface. As the Zn content is decreased below 2 wt.% Zn, the dominant phase changes from Ni 5 Zn 21 to (Ni,Zn) 3 Sn 4 .…”