Modeling Galden layer formation on PCB surface during Vapour Phase Soldering

Abstract

This paper presents a modeling approach of the Galden layer formation on the surface of Printed Circuit Boards (PCBs) during the Vapour Phase Soldering (VPS) process. The layer formation model is a supplement of a board level condensation model which calculates the condensate mass on the surface of the soldered PCB. The Galden layer formation model applies combined transport mechanisms including convective mass transport by the hydrostatic pressure difference in the layer and the gravity force; conductive and convective heat transport. The model applies the Finite Difference Method (FDM) and the three dimensional Forward Time Central Space (FTCS) method. The model can describe the dynamic formation and change of the Galden layer on the PCB surface and the change of the mass and energy flow in the condensate layer. This way the effect of the Galden layer changes on the heating of the soldered PCB can be investigated.