KAIST's internal chip cooling tech slashes energy use by 90% for AI data centers

New technique cools high-performance chips from the inside out

Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have developed a technique to carve microscopic liquid-cooling channels directly inside silicon semiconductor chips. Interestingly, the computer architecture slashed the energy required for cooling by pumping ordinary, room-temperature water straight through the chip's internal structure. "As the performance of AI semiconductors and advanced electronic packaging becomes increasingly limited by heat, we expect this technology to serve as a foundational cooling solution for future high-performance computing systems," said Professor Sung Jin Kim. The rapid advancement of high-performance AI chips has created a severe energy crisis for data centers, which require massive amounts of electricity both to power intensive computations and to cool down the resulting heat. Typical cooling methods, such as roaring air fans and external copper heat spreaders, are reaching their physical limits. Hence, the industry is urgently looking for thermal alternatives. To appreciate this development, you have to understand why standard liquid cooling is flagging. Most modern liquid systems rely on an external "cold plate" pressed against the outside of a chip. The coolant has to travel from one end of the hardware to the other. This long trek creates immense fluid resistance. It requires heavy-duty pumps pushing with massive pressure, which consumes a ton of energy. And at times, the fluid warms up along the way, leaving some parts of the processor chilled and others dangerously hot. The KAIST team developed a liquid-cooling technology that cools semiconductors from the inside out. It uses ordinary room-temperature water to tackle high-heat-flux conditions at the source. The design features multiple tiny inlets and outlets scattered uniformly across the chip. The innovation centers on a "manifold microchannel" structure embedded directly inside the silicon, which mimics an efficient logistics network by using multiple strategic inlet and outlet points. This decentralized design shortens the fluid's travel distance, reducing flow resistance and pumping pressure. The researchers used a multi-fidelity optimization framework to perfectly balance channel dimensions and flow rates. The KAIST team combined rapid 1D computational models with heavy-duty simulations to map an optimal, perfectly uniform flow. And the experimental results blew past expectations. Notably, the system registered a cooling Coefficient of Performance (COP) of 106,000. That is an abstract engineering metric, but the context is historic: it is ten times higher than the previous world record published in Nature in 2020. In plain terms, it means chip manufacturers need just one-tenth of the pumping power to remove the same amount of heat from a machine. Even under an extreme thermal load of 2,000 watts per square centimeter, the system kept the chip comfortably below 100°C (212°F). Yet, the most disruptive detail of the experiment is how it's made. The researchers didn't use exotic, hyper-expensive materials like synthetic diamond; instead, they used plain water. Furthermore, the entire fabrication process happens below 350°C (662°F). It means the process is entirely compatible with existing commercial semiconductor manufacturing lines. Foundries can integrate this plumbing technique into current chip designs without buying billions of dollars in new machinery. The development was published in the journal Energy Conversion and Management.

KAIST unveils breakthrough that could slash AI data center cooling power - The Korea Times

An image shows how a manifold microchannel cooling device directs coolant through microscopic channels inside a semiconductor chip to efficiently remove heat from high-performance processors. Coutesy of Korea Advanced Institute of Science and Technology As artificial intelligence systems demand ever more computing power, a team of Korean researchers says it has found a way to tackle one of the industry's most expensive and stubborn problems: heat. Researchers at the Korea Advanced Institute of Science and Technology said Tuesday they have developed a liquid cooling technology capable of reducing the power needed for semiconductor cooling to roughly one-tenth of current levels while delivering significantly higher efficiency. The team said the technology integrates microscopic cooling channels, thinner than a human hair, directly into semiconductor chips and combines them with a manifold structure that distributes coolant through multiple pathways. The design is intended to shorten the distance coolant must travel, reducing energy losses while improving heat removal. Researchers said previous manifold microchannel cooling systems often suffered from uneven coolant distribution, with some channels receiving more flow than others. To address that problem, the team optimized the structure so that coolant moves more evenly throughout the system. After fabricating the design on a silicon wafer, the researchers measured a coefficient of performance of 106,000. According to the team, that means a single unit of energy used for cooling can remove 106,000 units of heat. The researchers said the result is more than 10 times higher than the previous global benchmark reported in Nature journal in 2020. The system operates using room temperature water and does not require boiling-based cooling methods, nanostructured surfaces or expensive materials such as diamond, the researchers said. The team also said the technology can be integrated into existing semiconductor manufacturing processes without additional production facilities. Tests applying the design principle to data center cold plates showed cooling performance improvements of more than 30 percent compared with conventional systems. The findings were published Sunday in the journal Energy Conversion and Management. This article was published with the assistance of generative AI and edited by The Korea Times.