Abstract: With the increasing demand for lead-free and high integration of electronic packaging, the development of low-cost and high-performance lead-free packaging materials to effectively replace the traditional lead-containing materials has become a global focus. The Sn-0.3Ag-0.7Cu (SAC0307) solder with the lowest silver content in the currently developed Sn-Ag-Cu lead-free solder has the advantages of good ductility, impact drop resistance and low cost, but its reliability is reduced due to its high melting point, low mechanical properties and low thermal fatigue resistance. In order to further promote the development of low-silver SAC0307 solder for electronic packaging and improve its mechanical properties and reliability, the research of new low-silver SAC0307 composite solder has become one of the important research directions. The research status of SAC0307 composite solder with low silver content in recent ten years is elaborated. The research results on the modification of low-silver SAC0307 solder are reviewed and summarized from the aspects of adding alloy elements, metal nanoparticles, metal oxide particles, carbon nanoparticles and other non-metallic materials. It is expected to provide some help for the subsequent research and development of high-performance new low-silver SAC0307 composite solder.

Key words: Sn-0.3Ag-0.7Cu, alloy element, nanoparticles, intermetallic compound, mechanical properties