Thermal Characterization of Interlayer Microfluidic Cooling of Three-Dimensional IC With Non-Uniform Heat Flux

It is now widely recognized that three-dimensional (3D) system integration is a key enabling technology to achieve the processing speeds and performance needs of future microprocessor integrated circuits (ICs). To provide modular thermal management in 3D stacked ICs, interlayer microfluidic cooling scheme is adopted and analyzed in this study. The effects of cooling scheme and essential geometry variations on the routing completion and congestion of electrical interconnect are quantitatively analyzed. Also, the thermal and hydraulic performance of several two-phase refrigerants is discussed in comparison with single-phase cooling. The results show that refrigerants in two-phase flow are thermally preferred due to the higher heat transfer coefficients, and relatively constant fluid temperature throughout the microchannel. However, the large internal pressure and pressure drop act as significant limiting factors in realizing the merits of two-phase cooling. It is also concluded that integration of high performance hot-spot thermal management is a key to addressing a challenge of mass flow rate mal-distribution.