In this study, silicon carbide (SiC) reinforced lead-free solder (SAC305) was prepared by the powder metallurgy method. In this method SAC305 powder and SiC powder were milled, compressed and sintered to prepare composite solder. The composite solders were characterized by optical and scanning electron microscopy for the microstructural investigation and mechanical test. Addition of 1.5 wt. % and 2 wt. % ceramic reinforcement to the composite increased compressive strengths and microhardness up to 38% and 68% compared to those of the monolithic sample. In addition, the ceramic particles caused an up to 55% decrease in the wetting angle between the substrate and the composite solder and porosity was always increased with increase of SiC particles.

To fabricate a lead-free solder with better properties, a surface-modified precipitate calcium carbonate (PCC) was added as a reinforcement phase to tin-zinc (Sn-9Zn) solder. The surface modification of PCC was done by using electroless plating to deposit nickel (Ni) layer on the PCC. Based on microstructure analysis, a thin layer of Ni was detected on the reinforcement particle, indicating the Ni-coated PCC was successfully formed. Next, composite solder of Sn-9Zn-xNi-coated PCC (x = 0, 0.25, 0.50, 1.00 wt.%) was prepared. The morphology and phase changes of the composite solder were evaluated by using optical microscope and X-ray diffraction (XRD). Significant refinement on the grain size of Zn was seen with the additions of Ni-coated PCC, with a new phase of Ni3Sn4 was detected along with the phases of Sn and Zn. The wettability of Sn-9Zn was also improved with the presence of Ni-coated PCC, where the wetting angle decreased from 28.3° to 19.4-23.2°. Brinell hardness test revealed up to 27.9% increase in hardness for the composite solder than the pristine Sn-9Zn solder. This phenomenon contributed by the increased in dislocation resistance through Zener pinning effect and Zn grain refinement within the composite solder which enhanced the overall properties of the composite solder.