Establishing the Single-Phase Cooling Limit for Liquid-Cooled High Performance Electronic Devices

Abstract

The objective of this paper is to establish the cooling limit for forced single-phase liquid-cooling of high performance electronic devices such as CPUs, FPGAs and GPUs. This limit is established based on the design and optimization of a liquid-cooled copper cold plate populated with microchannels, which is used to cool a single chip with uniform heat flux. A shape optimization strategy based on the RSM (response surface method) was used to minimize pressure drop and maximum chip case temperature. The effects of the fin thickness and channel spacing were captured by the numerical simulation. The optimization was performed for constant values of coolant flow rate and chip power. The influence of fin geometry, channel geometry total heat transfer surface area on the hydraulic and thermal performance of the heat sink was determined using CFD (computational fluid dynamics) simulations at RSM design points. The optimum designs were achieved by minimizing a weighted objective function defined based on response parameters using the JAYA algorithm. Finally, a parametric study was performed to establish the thermal limit of the single-phase liquid-cooled heat sink within a constrained pressure drop of 10kPa. The best-performing heat sink shows a resistance 0.15 °C cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /W (based on chip area of 4cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ). The current proposed liquid-cooled heat sink can handle close to 170W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a thermal budget of 50°C from chip to the ambient under controlled pressure drop of less than 10 kPa.