Interfacial reaction between novel high entropy alloy SnPbInBiSb and Cu substrate

With the rapid development of electronic packaging technology, the high reliability of 3D integrated circuit packaging calls for new functional solder. In this study, a novel high entropy alloy SnPbInBiSb with a low melting point of 112.8 °C was fabricated and investigated. The low melting point and excellent wettability of SnPbInBiSb alloy prove its great potential as a new kind of solder applied in low-temperature electronic packaging. Moreover, the interfacial reaction of the Cu/SnPbInBiSb/Cu solder joint was studied. The sluggish diffusion effect and lattice distortion effect of SnPbInBiSb distinctly restrained the interdiffusion between alloying elements and Cu, thus hindering the growth of intermetallic compounds along the SnPbInBiSb/Cu interface.