CFD Analysis on Forced Convection Cooling of Electronic Chips

Abstract

For more than a decade, investigations have been conducted to better understand the fluid flow and heat transfer characteristics in silicon-based microchannel heat sinks designed for applications in electronic cooling. These non-circular channels and silicon based microchannel heat sinks combine the attributes of high material compatibility, high surface area per unit volume ratios and large potential heat transfer performance with highly sophisticated and economic fabrication process. These advantages make these silicon based microchannel heat sinks extremely attractive for a wide variety of commercial applications. The present work addresses electronic chips cooling with forced convection of water in silicon based single microchannel heat sinks by the help of a commercial CFD software FLUENT. The computational domain is discretized with non-uniform grids on the flow face but uniform grid along the flow. For single microchannel, the grid is generated by implementing Gambit software, which is incorporated with Cooper method for 3-dimensional grid generation. The pressure, velocity and temperature contours at inlet and outlet are presented along with the variation of these fields in flow direction for visual comparisons. The output of the single microchannel is in good agreement with the available results for silicon substrate. The Nusselt number variation along the flow direction is presented and compared for three different flow rates. The convection heat transfer co-efficient is also presented for above three cases. During simulation of the aforementioned cases, Semi-Implicit Method for Pressure Linked Equations (SIMPLE) with second order upwind scheme is implemented for laminar fully-developed flow. The continuity, momentum and energy equations are solved in a segregated manner because of its accuracy. As the fluid flows in a icrochannel, the laminar flow is considered during simulation along with the energy equation. The single microchannel solution is converged quickly with minimum number of iterations. The post processing of the output results are carried
out by Excel.