Novel Compact-Thermal-Model Approach to Estimate the Heat Spreading Effects of Flip-Chips on PCB regarding Laminar Flow Regimes

Today, electronic and thermal engineers want to figure out, which location are the most compliant one, to ensure electronic function of the system and get a reliable thermal design. Numerical simulations can help to understand thermal paths and interactions between electronic parts nearby. However, there are often time consuming, to set-up all material parameters and fluid flow properties. The usage of Compact Thermal Models (CTM) are often used for power application [1] and can provide first solutions to heat transfer via solid substrate, thermal spreading and solid to fluid interactions. Those CTM cannot fully replace a complex fluid mechanical analysis with a Computational Fluid Dynamics (CFD) software environment. Furthermore, CTM can take place in preliminary studies during the early design phase of electronic systems within the implementation of key parameters e.g. thermal conductivity of the substrate, fluid flow velocity, power losses and different dimensions of the system. This paper continuous the experimental and numerical study of [2, 3] to complete an approach for CTM based thermal equivalent resistor networks with consideration of dynamic heat spreading along the substrate and laminar convective fluid interactions on typical Printed Circuit Boards (PCB) with micro-electronic Flip-Chip (FC) assemblies.