Investigations on Heat Extraction in Multilayer PCB Structures

This article presents experiments of the measurement of heat transfer in multilayer structures of FR4 material with different topologies at the first and second levels in the presence of thermoal vias. For the purpose of the experiment a power diode in SMC package is used as heat source and copper pads are placed on the second conductive layer in order to extract the heat. The thermoal vias, connecting the top solder pads and the copper pads, are designed with a different diameter and the structures are electrically charged. The goal is to investigate the change in the diode temperature when applying a different power supply. This article illustrates the heat dissipation dependence on the diameter and thickness of the thermal-vias. The measurement of the temperatures for obtaining the results is done by a thermal camera FLIR P640.