CFD simulations of wave soldering on through-hole printed circuit assemblies

Abstract

This paper presents the main observations and results, which have been collected from wave soldering simulations for a lead-free SnAgCu (SAC) solder, in terms of solder shape, penetration and electrical continuity. The simulation models comprise of steady state transitional shear stress transport (SST) melting/solidification models of a single pin-through hole (PTH) configuration on a printed circuit board (PCB). The simulations make use of the commercially available ANSYS Fluent Computational Fluid Dynamics (CFD) solver. The simulation models have been developed to the extent that they are capable of capturing and investigating some of the physically salient features, which dominate wave soldering processes, such that improvements in efficiency/efficacy can potentially be pursued. The simulations also account for the influence of variations in solder material properties, such as viscosity, surface tension and density with respect to temperature. Furthermore, within this paper, areas are highlighted as to how to improve upon and extend the applicability of the models through future development.