Inhibition of intermetallic compounds growth at Sn–58Bi/Cu interface bearing CuZnAl memory particles (2–6 μm)

In total, 0.5 wt% CuZnAl memory particles with the diameters (2–6 μm) were added into Sn–58Bi solder in order to enhance the properties of solder joints in electronic packaging. The interface reaction and the growth kinetics of intermetallic compounds at Sn–58Bi/Cu interface and Sn–58Bi–0.5CuZnAl/Cu interface were studied systematically at 250 °C, 230 °C and 210 °C, the results indicate that the growth rate of intermetallic compounds (IMC) at both interfaces at 250 °C was higher than that at 230 °C, the addition of CuZnAl memory particles can reduce the diffusion coefficient of interfacial IMC, and however, at 210 °C the inhibition effect of CuZnAl particles was so small. Based on the transient liquid phase bonding, it is demonstrated that Cu/Sn–58Bi–0.5CuZnAl/Cu-bonded joints can achieve the chip stacking in 3D packaging with 10 μm thickness with obvious superiority.