Scaling of Components for Explicit Modelling of Heat Transfer during Vapour Phase Reflow Soldering

Heat transfer aspects of condensation during vapour phase soldering on aligned PCB-based surfaces

“…It is apparent from the literature that only a few are investigating the heat transfer itself and the layered processes in depth. One of the first summary to give a proper description via an explicit description was presented by Leider (2002); however, a more recent approach involved a more sophisticated approach on modelling of the heat transfer on a Printed Circuit Board (PCB) assembly in vapour (Straubinger et al, 2019). The description of the heat transfer originated from Newton's law of heating, and the relevant heat transfer coefficient was derived from the wall-condensation model of Nusselt and the consequential works of Bejan (1991).…”

“…While the first description could fit the model of a horizontal PCB (considered as a thin, horizontal wall), the components need attention from this specific aspect. The approach, where Bejan's (1991) extended model was used to describe the heat transfer on the components, was found to be non-universally applicable for SMD components (Straubinger et al, 2019). The classical analytical models are starting to deviate from measured data, as the geometries are scaled down and the models are extended in verticality; therefore, a refined understanding is required from the aspect of condensation regarding all wall orientations.…”