Critical heat flux limiting the effective cooling performance of two-phase cooling with an interlayer microchannel

The cooling problem on integrated circuits (ICs) has emerged as the primary issue for higher performance of modern processors and three-dimensional ICs (3D ICs) in particular. Cooling systems with interlayer microchannels in 3D ICs have been widely studied as a promising cooling system for a high-performance processor. However, two-phase cooling systems for 3D ICs cooling have rarely been studied especially in interlayer microchannel structures. In this paper, we report a comparative study on cooling performance of single-phase cooling with water and two-phase cooling with R134a in an interlayer microchannel. The microfluidic and heat transfer problem was solved by using ANSYS Fluent 16.1. Contrary to the general view that two-phase cooling is better than single-phase cooling, we found that two-phase cooling with R134a is more efficient only in the heat flux of below 12 kW/m² than single-phase cooling with water. The critical heat flux (CHF) was the main limitation of two-phase cooling to deal with a higher heat flux at a given mass flux.