Effect of surfactants on the chemical preparation of tin-silver-copper nanoparticles

SnAgCu alloys with low melting points and solderability are good candidates for Sn/Pb eutectics. In this paper, Sn-3.0Ag-0.5Cu nanoalloy powders were prepared by a chemical co-reduction method. The microscopic morphology, phase composition and melting behavior of the powders were analyzed with emphasis on the effect of surfactants on the powder particle size. The results showed that the average particle size of the powder was well controlled by the synergistic effect of the surfactants 1,10-phenanthroline and PVP, and the average particle size of the powder obtained was about 19 nm when the mass ratio of 1,10-phenanthroline to PVP was 4 and the addition amount was 10% of the precursor mass. The powder consists of three phases β-Sn, Ag3Sn, and Cu6Sn5. The initial melting temperature of the powder is approximately 185.8 °C, which is close to the melting point of conventional Sn/Pb solder (183 °C).