Interfacial structures and mechanical properties of Cu/Sn/Cu containing SiC nanowires under transient liquid phase bonding

In order to achieve low-temperature bonding and high-temperature service, Cu/Sn/Cu and Cu/Sn-0.6SiC/Cu structure were fabricated by transient liquid phase (TLP) bonding, and the microstructure evolution of intermetallic compound (IMC) and mechanical performance of TLP bonding solder joints were investigated. The results demonstrated that the scalloped Cu 6 Sn 5 IMC and lamellar Cu 3 Sn IMC formed at Sn/Cu interface gradually grew up in both solder joints as the bonding time increased. The asymmetrical growth of IMC was formed on both sides at TLP solder joints interface, whereas the interfacial IMC growth rate of Cu/Sn-0.6SiC/Cu was smaller than that of Cu/Sn/Cu solder. After TLP bonding for 120 min, Cu/Sn/Cu structure was composed of total Cu 6 Sn 5 and Cu 3 Sn IMC and Cu/Sn-0.6SiC/Cu structure still contained remaining Sn phase. SiC nanowires (SiC NWs) dispersed in the solder matrix could impede the growth path between Sn and Cu, so SiC NWs doped to Sn solder could slow down the IMC growth. Moreover, introducing SiC NWs could promote the shear strength of composite solder compared with Sn solder joints during TLP bonding. • The effect of SiC nanowires on the interfacial evolution of pure Sn solder by transient liquid phase bonding was studied. • In previous studies, the addition of SiC nanowires to pure Sn solder in three-dimensional packaging has not been reported. • This research can provide a theoretical basis for the modification of lead-free solder in electronic packaging.