Novel Sn-0.7Cu composite solder reinforced with ultrafine nanoscale nickel particles/porous carbon

Abstract

In this study, the nickel-based metal organic framework (Ni-MOF) was carbonized at high temperature and the nanoscale nickel particles anchored in the carbon skeleton ([email protected]) with flake structure were obtained. The composite solders were subsequently prepared successfully by adding the [email protected] flakes to Sn-0.7Cu solder. The effects of [email protected] on the properties, microstructure and interface reaction of the Sn-0.7Cu solders were systematically investigated. The results showed that the [email protected] flakes had a negligible effect on the melting point of the solders and improved the wettability significantly. The wetting angle decreased by 15.04% when the [email protected] was 0.08 wt% in content. In addition, the size of matrix β-Sn grains were significantly reduced and the matrix β-Sn grains appeared very fine structure after adding the [email protected] flakes. Meanwhile, the elongated (Cu, Ni)6Sn5 phase transformed from rod-shape to dot-shape. During the reflow process, the morphologies of intermetallic compounds (IMCs) gradually changed from shell-shaped to continuously planar, and their thickness decreased by 26.6%. The (Cu, Ni)6Sn5 forming at the interface and the porous carbons distributing in solder matrix effectively hindered the diffusion of Cu and Sn respectively and retarded the growth rate of IMCs.