Thermal Management in High-Density High-Power Electronics Modules Using Thermal Pyrolytic Graphite

Tremendous effort is going on towards the packaging of power electronics modules to reduce the parasitic impedances and in turn, the voltage spikes during switching transients of power devices. The heat dissipated in terms of switching losses for high frequency applications need to be eliminated further to have some flexibility regarding the layout and, for the safe functioning of a power module by reducing junction temperature. Thermal pyrolytic graphite (TPG), with its high basal-plane thermal conductivity along the vertical direction helps direct heat towards the module bottom (cooling system), whereas its extremely low through-plane thermal conductivity along the horizontal direction guarantees minimum heat coupling among devices placed on the substrate surface. FEA simulations to verify thermal benefits of TPG and experimental results have been shown in this work which validates the junction temperature drop of up to 17 ℃ when using TPG as substrate and heat spreader compared with traditional materials.