Interfacial reaction and properties of Sn/Cu solder reinforced with graphene nanosheets during solid-liquid diffusion and reflowing

In this paper, different mass fractions (0, 0.01, 0.03, 0.05, 0.07, and 0.09 wt.%) of graphene nanosheets (GNSs) were selected as a strengthening phase to promote the performances of Sn/Cu solder joint. The wettability and shear performance of Sn-xGNSs/Cu solder and the growth behavior of intermetallic compound (IMC) during solid-liquid diffusion at 250 degrees C and under multiple reflows (1, 2, 4, and 8 times) were systematically discussed. Results exhibited that the wettability of GNSs doped solder improved as GNSs added and 0.05% GNSs addition would promote the spreading area of the composite solder effectively. The scalloped Cu6Sn5 IMC layer was formed at the interfacial Sn-xGNSs/Cu. Based on the adsorption theory, GNSs doping was conducive to prohibiting the interfacial IMC growth of Sn solder reinforced with GNSs during soldering process and reflowing process. Meanwhile, the IMC overtly became thinner in Sn-0.05GNSs solder with comparison to plain solder. What's more, GNSs addition brought about an enhancement in the mechanical performance of GNS-containing solder. The fracture surface of solder joint after doping GNSs transformed from a brittle pattern to a ductile pattern.

Automated summary

This study investigated the use of graphene nanosheets (GNSs) at different mass fractions to enhance the performance of Sn/Cu solder joint. Results showed that 0.05% GNSs addition effectively promoted the spreading area of the composite solder while inhibiting the growth of intermetallic compound (IMC) layer. Additionally, GNSs doping improved the mechanical properties of the solder joint, transforming the fracture pattern from brittle to ductile.