Influence of 0.03 wt.% Carbon Black Addition
on the Performance of Sn-3.5Ag Lead-Free Solder
In an effort to improve the performance of lead-free solder, Sn-3.5 wt.%Ag (Sn-3.5Ag) solder alloy with 0.03 wt.% carbon black was prepared under high pressure (5.5 GPa) and high temperature (1200°C). We have investigated the microstructure, melting behavior, and mechanical properties of the alloy using x-ray diffraction, differential scanning calorimetry (DSC), Vickers hardness testing, tensile testing, and scanning electron microscopy (SEM). The melting point was found to be unchanged, while the hardness and the tensile strength increased with the addition of carbon black. SEM images showed that the average thickness of the intermetallic compound (IMC) layer decreased with the addition of carbon black, indicating improvement in solder joint reliability.