Discrete phase method particle simulation of ultra-fine package assembly with SAC305-TiO2 nano-reinforced lead free solder at different weighted percentages

摘要

This paper presents a 3D numerical simulation of nano-reinforced lead (Pb)-free solder at the ultra-fine joint component for 01005 capacitor with dimension of 02 x 02 x 0.4 mm(3). The nano-reinforced particles introduced in the Sn-3.0Ag-0.5Cu (SAC305) solder is titanium oxide (TiO2) nanoparticles with approximate diameter of 20 nm at different weight percentages of 0.01, 0.05 and 0.15 wt% respectively. The 3D model developed is based on the reflow thermal profile of nano-reinforced Pb-free solder in the wetting zone temperature of 217 C-239 degrees C. A two way interactions utilizing both volume of fluid method (VOF) and discrete phase method (DPM) are introduced in the current study. The study effectively shows the distribution of the nanoparticles as it is being doped in the molten solder after undergoing soldering process. Based on the findings, it was shown that good agreement can be seen between experimental data obtained using High Resolution Transmission Electron Microscope (HRTEM) system as compared to multiphase DPM based simulation. At weight percentage of SAC305 + 0.05% TiO2 nanopartides, the nanoparticles are well distributed. The fillet height of nano-reinforced solder also meets the minimum requirement for 01005 capacitor. Additionally, as the weight percentage of the doped nanoparticles increases, the time required for the formation of wetted solder also increases. In terms of the velocity and pressure distribution of the nano-reinforced lead (Pb)-free solder, higher weight percentage of doped nanoparticles have higher velocity distribution and lower pressure distributions. (C) 2017 Elsevier Ltd. All rights reserved.