SAC305 nanocomposite solders were successfully produced with addition of different weight percentage (0.25, 0.50, 0.75 and 1.0 wt.%) of TiO2 and Al2O3 nanoparticles. This study examined how the addition of TiO2 and Al2O3 nanoparticles affects the microstructural changes during the growth of intermetallic compounds (IMCs) in the SAC305 solder alloy. The results show the addition of nanoparticles alter the morphology of IMC layer and restrict the formation of the IMC layer. The morphology of the IMC layer transitions from an elongated scallop-like shape to a rounded scallop-like shape, and subsequently evolves into a wicker shape with additional additions of TiO2 and Al2O3 nanoparticles. The thickness of the IMC layer significantly decreases by 22.84% with the addition of 0.50 wt.% of TiO2 and Al2O3 nanoparticles. Inhibition of intermetallic compound growth of SAC305 nanocomposite solder effectively resulted at 0.50 wt.% addition of TiO2 and Al2O3 nanoparticles. However, excessive addition of weight percentage of TiO2 and Al2O3 nanoparticles promotes the growth of IMC layer.