Solder paste reflow modeling

Abstract

Solder paste printing and reflow are well established processes for producing solder joints in electronic assemblies. Solder paste consists of a dense suspension of solder particles in a liquid medium (vehicle) that acts as an oxide reducing agent (flux) during reflow, cleaning the metal surfaces of oxides. This paper reports on attempts to model the physical and chemical processes occurring during solder paste reflow using computational fluid dynamics (CRD). Axisymmetric, 2 dimensional and 3‐dimensional models are described, and a method of reproducing oxide‐like behaviour in these models in introduced.