2D numerical modeling of the thermal and hydraulic performances of a very thin sintered powder copper flat heat pipe

As integrated circuits become faster and more densely packed with transistors, conventional methods of cooling are not able to overcome the heat problem. Recently heat pipes have proven their efficiency for many applications where high heat fluxes suppress the possibility of using conventional cooling systems. The presented work aims to find efficient passive thermal solution for double sided electronic substrate, part of multifunctional 3D electronic module (European project "Microcooling"). Integrating heat pipe into the double sided slices satisfies the heat transfer requirements and minimizes the overall dimensions of the 3D packaging. To improve the design of the device under test and to provide better understanding of the physical phenomena of the fluid flow and heat transfer in the heat pipes, simplified 2D model was created. Further, according to the real prototype and the experimental setup, the simplified model was developed in more detailed formulation. The results are presented in terms of liquid and vapor pressures within the heat pipe and maximal heat power. Experimental validation, which proves that the new model can be used to predict the heat capacity and to improve the design of flat heat pipes for specific applications, is also presented.