Design and Analysis of Direct Liquid Multi-Jet Impingement Schemes for Electronics Applications Available to Purchase

The meteoric rise in cooling requirements of commercial computer products mandates the development of extremely aggressive thermal management techniques. Direct liquid jet impingement cooling is one such method, especially if water is the coolant. While the use of water would require advanced chip packaging, it is necessary to investigate, design, and optimize systems using direct water cooling, to meet the cooling needs of the future. The thermal performance of two direct liquid jet impingement configurations, are characterized and studied, via CFD (Computational Fluid Dynamics) models constructed using a commercial numerical solver. The hydraulic performance is analytically estimated using a basic loss coefficient based model. In the first scheme, the coolant is collected at the periphery of the chip, while the second design incorporated fluid return for each jet within the vicinity of the jet itself. A square 10×10×0.75 mm³ chip, dissipating 400W, and cooled by water at 32°C, is considered as the representative example for the analysis. The effect on thermal performance of jet density, in the range of 1–36 jets/cm², for both schemes, is investigated, for several feasible flow parameters, i.e. inlet jet velocity and volumetric flow rate. The peripheral return configuration was found to outperform the parallel return for all of the cases investigated. Barring one case, the peripheral return data from this study, for the effective heat transfer coefficient, compared with Martin’s correlation to within 17% (average) with a standard deviation of 8%. The convective thermal resistance was found to constitute an important part of the total junction-to-ambient thermal resistance.