Investigations on Heat Transfer with Different PCB Substrates during Vapour Phase Soldering

The purpose of this article is to present our experiments with Vapour Phase Soldering, where the temperature distribution and heat transfer mechanisms were investigated on four test-boards with different substrates. We developed a method to measure the temperature gradients on-board inside an experimental vapour phase soldering oven. VP soldering process is suitable for consistent and rapid heating on boards from small scale to large ones with power components showing considerable thermal capacities. The measurements were performed on FR4, ceramic, alumina composite and flexible substrates, where the results show significant differences between the different materials, and point to investigations with thermal diffusivity for future research.