POROUS MEDIA THERMAL MODELING OF AN ELECTRONIC CHIP WITH NON-UNIFORM POWER DISTRIBUTION AND COOLED BY MICRO-CHANNELS

Micro-channels are used for the cooling of electronic chips. However, the 3D-CFD modeling of the large number of channels in a full chip requires huge number of meshes and computation time. Although porous media modeling of micro-channels can significantly reduce the effort of simulation, most porous media models are based upon the assumption that the surface heat flux or temperature is uniform on the chip. In reality, the heat flux on the chip is usually highly non-uniform. As a result, the heat transfer coefficient along the micro-channel is not uniform. In the present study, the porous media model considers the simultaneously developing entrance effect at the micro-channel inlet, and the thermally developing entrance effect due to the severe heat flux variation along the channel. Duhamel integral is used to determine the heat transfer coefficient variation corresponding to the heat flux distribution along the channels, and comparisons are made with the rigorous conjugate conduction-convection modeling. The computing cost of this modeling method is only about 1% (including one time of iteration) of 3D-CFD simulation. To demonstrate this approach, a full scale electronic chip with realistic power distribution on the surface is modeled, and the temperature map on the chip's heating surface is provided.