Improved CFD analysis of wave soldering in pin through-hole technology

Analysis of solder penetration, shape and electrical continuity assessed using wave soldering simulations for a lead-free SnAgCu (SAC) solder, along with comparisons to real wave soldering, are presented in this paper. The presented results utilise steady state shear stress transport (SST) melting/solidification models of a single pin-through hole (PTH) on a printed circuit board (PCB) where the ANSYS Fluent Computational Fluid Dynamics (CFD) solver is used for the simulations. The model development is sufficiently mature such that they are capable of capturing and investigating some of the physically salient features, which dominate wave soldering processes, in order that improvements can potentially be pursued. The influence of variations in solder material properties, such as viscosity, surface tension and density with respect to temperature are also incorporated within the models. The results represent an improvement on previous models, particularly with regards to pin tips and, furthermore, areas are identified for further development.