Modeling of thermal via heat transfer performance for power electronics cooling

For power electronics and Light Emitting Diode (LED) lighting applications, thermal management represents a critical factor having important consequences on electrical performance and overall cost of the assembly. Although advanced solutions for heat removal like Isolated Metal Substrates (IMS) base materials or thermally conductive epoxies have entered the market for a few years they still have a high price tag and add significant manufacturing costs to the finished assembly. Obtaining a good thermal management by using conventional materials and manufacturing techniques is often a key design challenge that engineers have to overcome. By creating thermal paths from one layer to another, the equivalent cooling area for an electronic component can be significantly increased thus lowering the junction-to-ambient thermal resistance which is the main indicator of cooling performance. These thermal paths between layers are commonly defined as through-hole plated vias connected to copper areas. Our paper presents a study of the thermal performances of through-hole thermal vias used for heat transfer between layers on printed circuit boards. Different geometries and scenarios are investigated by simulation using Computational Fluid Dynamics (CFD) software in order to determine steady state thermal behavior.