Identification of influencing PCB design parameters on thermal performance of a QFN package

QFNs are electric components that are producing a substantial amount of heat during operation due to significant power loss. Resulting elevated temperatures can lead to critical damage of the chip and the package which could cause a loss of functionality. Therefore, controlling the maximum temperature within the package is crucial. Using thermal vias embedded in the PCB underneath the QFN is a common approach to control the heat flow. In this paper a simulation approach is presented using 3D-Finite-Element-Modeling to identify the impact of influencing parameters on the temperature distribution within the package. First, a review about relevant literature is given. This paper differs from the available literature by looking more detailed in the 3D-modelling aspect of thermal via designs. It is focused on a simulation approach to determine the temperature distribution within the soldered component and the PCB. Therefore, the build-up of the model is explained and applied material properties are given. Results for the determined temperature distribution for the reference system are presented. Furthermore, geometrical parameters are varied to identify main influencing parameters.