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A thermal simulator which can perform transient thermal analyses of vertically stacked 3D integrated circuits with inter-tier Microchannel Liquid Cooling.

Among various IC configurations, 3D stacked integrated circuits (3D ICs) comprise an attractive proposition for servers and data centers. In fact, the global market for 3D ICs is expected to reach $8.6 billion by 2021, up from only $2.9 billion in 2014. However, the main factor that impedes market growth is high heat dissipation levels. This is a major worry for server management because of the explosive growth of high-performance computing systems, increasing circuit densities, and proliferation of Multi-Processor Systems-on-Chips (MPSoCs).


Naturally, researchers worldwide have evinced keen interest to develop efficient cooling systems, and there is a body of literature on the subject. Nonetheless, it is imperative to develop tools that can be applied to next-gen IC thermal simulators. In this context, researchers at EPFL’s Embedded Systems Laboratory have taken the lead by developing a thermal simulator called 3D-ICE, which can perform transient thermal analyses of vertically stacked 3D integrated circuits with inter-tier Microchannel Liquid Cooling.

3D-ICE, which stands for 3D Interlayer Cooling Emulator, is based on the Compact Transient Thermal Model (CTTM) developed by the researchers. 3D-ICE is built on an architecture consisting of vertically stacked dies with microchannel cavities glued together with bonding materials, with TSVs running through the microchannel walls. The model works seamlessly with existing thermal CAD tools for ICs. The performance evaluation of the model, relative to a commercial computational fluid dynamics (CFD) simulation tool, revealed a maximum temperature error of only 3.4%, but a speed-up of 975x.

3D-ICE is targeted toward VLSI designers, heat sink engineers, and researchers. It was released in 2010 as an open source Software Thermal Library written in C in Linux. Since then, it has become a trusted tool with more than a thousand downloads.

3D-ICE is the outcome of collaborative research among various laboratories of EPFL and IBM Zurich. Its core team includes principal authors Arvind Sridhar and Alessandro Vincenzi, IBM scientist Thomas Brunschwiler, and supervisors Martino Ruggiero and David Atienza.

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