Performance analysis and shape optimization of a water-cooled impingement micro-channel heat sink including manifolds

Abstract

Impingement micro-channel heat sinks are in general preferred over parallel flow micro-channel heat sinks owing to the reduced pressure drop. Splitting the flow in two branches cuts the flow rate and path in half, which leads to lower pressure drop through the channels in impingement heat sinks compared to a parallel flow heat sink. A numerical model was developed to predict the heat sink performance. Because of the significant effect that inlet and outlet manifolds (distributor and collector) have on the heat sink hydraulic and thermal performance, the numerical model includes them. The model was validated both for hydraulic and thermal performance using experimental data. The model was used for shape optimization of the heat sink in constant chip power, coolant inlet temperature and flow rate as well distributor and collector geometry. A parametric study was performed to estimate the effect of the geometric design parameters on the hydraulic and thermal resistances as the response parameters. The chip-base interface temperature profile was very different from typical parallel heat sinks. The coefficient of performance as a measure of the heat sink overall performance (hydraulic and thermal) was measured experimentally. Furthermore, the sensitivity of the heat sink coefficient of performance to chip power, coolant inlet temperature and flow rate was estimated using a regression model fitted on the obtained experimental result.