Investigating the dynamic changes of the vapour concentration in a Vapour Phase Soldering oven by simplified condensation modelling

The dynamic changes of the vapour concentration during Vapour Phase Soldering (VPS) process was investigated by a board level modelling approach of vapour condensation. This model is based on a process (machine) level model which calculates the vapour and temperature space in the VPS tank. The board level condensation model is embedded into the process level model and runs as a co-simulation. The condensation model applies combined transport mechanisms including heat transport by heat conduction; mass transport by phase change during the condensation of the Galden liquid; and energy transport caused by mass transport. The model uses a special dew point calculation which was developed for Galden liquid by experiments. The model can describe the temperature change of soldered assembly, and the vapour consumption around the assembly. This way the effect of the soldered assembly on the vapour space can be investigated. It was also shown that the heat conduction of the vapour space and the immersion speed of the assembly cannot be neglected.