Liquid Flow Analysis in Porous Media for Large Vapor Chamber With Multiple Heat Sources

The increasing addition of hot components on a single module comes with the challenge to cool the module. The cooling challenges are due to the presence of hot spots and the reduce space for attaching heat sinks to each component. The proposed cooling solution for a multi-chip module is a single vapor chamber shared amongst the multiple heat sources. Designing an application-optimized vapor chamber requires detailed understanding of the different processes occurring, including heat transfer by conduction, two-phase heat transfer, and fluid mechanics in porous media. In this work, a relatively large module with many heat sources is considered. We present a case of two 100W heat sources surrounded by eight heat sources of 10W each. We explore different configurations and their capillary limitations for a vapor chamber (110 mm × 110 mm). We present the comparison of numerical results using two point flux approximation method, CFD model, and a simplified model using potential flow theory to represent flow in the porous media. Results are used to analyze the capillarity limitation of the large vapor chamber in delivering liquid flow to heat source locations for steady state.