Development od SiC reinforced SnCu and SAC based lead-free solder composite via powder metallurgy route

Abstract

Nowadays, composite solder has gain researcher’s attention due to its promising improvement in physical and mechanical properties for lead free solder. This study was carried out to investigate the effect of SiC particle on microstructure evolution, physical and mechanical properties of SAC and SnCu based solder alloys. Both SAC and SnCu composite solders were synthesized by powder metallurgy method (PM), which consistsof several processes such as mechanical blending, compaction and sintering. Five different weight percentages of SiC particles; 0.00, 0.25, 0.50, 0.75 and 1.00 were mechanically blended with SAC and SnCu lead-free solder. There were two phases involved. The first phase was investigation on the bulk composite solder properties and the second phase was investigation on the as-soldered composite solder connection. The wettability result showed the smallest contact angle for SnCu-SiC which is 18.60 degrees with 0.75 wt.% of SiC. While the smallest contact angle for SAC-SiC which is 20.00 degrees with 1.00 wt.% SiC. The optimum density value for SnCu-SiC and SACSiC were 7.162 g/cm3 and 7.274 g/cm3 respectively when 0.75 wt.% of SiC. The hardness values for SnCu-SiC samples was 13.0 HV starting at 0.75 wt.% to 1.00 wt.% of SiC addition while SAC-SiC reach the maximum value 18.6 HV at 1.00 wt.% of SiC addition. The shear strength for SnCu-SiC reach 14.95 MPa as an optimum value with addition 0.50 wt.% of SiC. After that, the value decreased until the addition 1.00 wt.% of SiC. The optimum value of SAC-SiC shear strength, 17.79 MPa was reached with the addition 0.50 wt.% of SiC. After that the value was decreased when the SiC addition has exceeded 0.75 wt.%. The electrical resistivity (ρ) of bulk SnCu-SiC and SAC-SiC composite lead-free solders was measured with a four-point probe. The result showed there only slightly affected by the addition of SiC for SnCu-SiC and SAC-SiC composite lead-free solders. The value of electrical resistivity for SnCu-SiC and SACSiC composite solder are decreasing when 0.75 wt. % and 1.00 wt. % of SiC particles were added which is their value is 1.18 μΩ.cm, 1.12 μΩ.cm, 0.88 μΩ.cm and 0.81 μΩ.cm respectively. As overall, the result detailed in this work indicate that the addition of SiC particles into SnCu and SAC based lead-free solder able to enhance their physical and mechanical properties.