In early 2026, NVIDIA officially unveiled the heat dissipation solution for its next-generation Vera Rubin architecture GPU—a combined process of "diamond-copper composite heat dissipation + 45°C warm water direct liquid cooling". The news sent the entire semiconductor industry into an uproar. How has a single "stone" been chosen by the chip giant as the heat dissipation partner for the next-generation computing power core?

The answer lies in a staggering set of figures. The thermal design power (TDP) of NVIDIA's GPUs has soared from 400W for the A100 in 2020 to 700W for the H100 and 1200W for the B200. The Rubin architecture has directly broken through 2300W, and the next-generation Rubin Ultra is expected to surge to 3500W. Over six years, the power consumption has nearly multiplied by nine. The core area of a chip is no bigger than a fingernail, yet it has to bear heat equivalent to that of a household induction cooker. Traditional heat-dissipating materials such as copper and aluminum are already far from sufficient.

Heat dissipation has evolved from a "nice-to-have" feature to the biggest bottleneck restricting the release of AI computing power. Diamond, however, is widely recognized in the industry as the "game-changer" that can break this deadlock.

The demand for computing power in AI training and inference is endless, and chip power consumption has been rising accordingly. When the power consumption of a single chip approaches 2300W and the local heat flux exceeds 1000W/cm², the physical ceiling of traditional heat dissipation solutions is completely broken through.

Air cooling? The volumetric heat capacity of air is only about 1/3500 of that of water, and the upper limit of 30 kW per cabinet has long been broken. Pure copper heat sink? The thermal conductivity of copper is only about 400 W/(m·K), and it is simply too late to "move" the heat away in the face of the terrifying heat generated in an area the size of a fingernail. Heat spreader? It is also stretched thin in the face of extreme heat flux density.

Complicating matters further is the issue of "local hotspots." Modern AI chips feature extremely high transistor density internally, so heat is not distributed evenly but instead accumulates intensely in tiny areas. Traditional materials conduct heat too slowly to keep up with the rate of heat generation, and once a chip triggers frequency reduction protection, its computing power takes an immediate hit. Heat dissipation capability has thus become the physical boundary of AI computing power.

Diamond is known as the "ceiling" of heat dissipation materials, primarily due to its terrifying thermal conductivity. The thermal conductivity of natural type IIa single-crystal diamond at room temperature is as high as 2000-2200 W/(m·K), and high-purity CVD synthetic diamond can also reach 2000-2400 W/(m·K). What does this mean? It is about 5 times that of copper and 10 times that of aluminum. A small piece of diamond the size of a fingernail can theoretically dissipate 2000 watts of heat.

Where does this ultra-high thermal conductivity come from? Diamond has a cubic crystal structure, and each carbon atom forms regular tetrahedral covalent bonds with four adjacent carbon atoms through sp³ hybrid orbitals. All valence electrons are locked in the covalent bonds with no free electrons, so heat is not transferred by electrons but by "phonons" generated by the vibration of carbon atoms propagating at high speed in the crystal lattice. The diamond crystal structure is highly stable with minimal phonon scattering and damping, allowing heat to be conducted out almost at "full speed".

High thermal conductivity is not enough. When a chip is in operation, it undergoes repeated thermal expansion and contraction. If the thermal expansion degree of the heat-dissipating material is inconsistent with that of the chip, huge thermal stress will be generated, leading to interface delamination, solder joint fracture, and chip warpage.

The coefficient of thermal expansion of diamond is approximately 1.0-1.5×10(-6)/K, which is very close to that of silicon chips at 2.6×10(-6)/K. In contrast, the coefficient of thermal expansion of copper is about 17×10(-6)/K, and that of aluminum is about 23×10(-6)/K, an order of magnitude different from silicon. Diamond can "breathe synchronously" with the chip, greatly reducing damage caused by thermal cycling. It will not crack or fail under tens of thousands of temperature cycles, fundamentally ensuring the long-term reliability of the chip.

Diamond also has an easily overlooked advantage: it is an excellent electrical insulator. Because all valence electrons are bound by covalent bonds, no free electrons participate in conduction. This means the heat dissipation layer can be placed directly close to the core area of the chip, without the need for an additional insulating isolation layer like in metallic heat dissipation materials.

This is crucial for high-density packaging, multi-layer stacking, and 3D chip architectures. The heat dissipation layer works directly "in close contact" with the chip, which not only simplifies packaging design but also improves the reliability and integration of the overall system.

There is not just one way to achieve diamond-based heat dissipation; there are currently three mainstream paths in the industry, each with different performance and cost characteristics.

Direct Growth of Diamond Thin Films — Diamond thin films are directly grown on silicon substrates via the CVD method to serve as the heat dissipation layer for chips. It offers the highest integration level but faces great process difficulties and size limitations, and is currently mostly in the R&D and verification stage.

Diamond-copper composite materials — composites made by combining diamond particles or fibers with a copper matrix have a thermal conductivity of 600-1000 W/(m·K). They balance high thermal conductivity with machinability, and their cost is only one-fifth to one-tenth that of pure diamond. This is currently the fastest route for industrialization and commercialization, and NVIDIA's Vera Rubin adopts exactly this solution.

Diamond Substrates and Liners — Using large-size diamond wafers as the carrier substrates for chips solves the heat dissipation problem from the ground up. They offer the highest thermal conductivity, but manufacturing large-size single crystals is extremely challenging. At present, China can only produce 1-2-inch ones, with extremely high costs. In the short term, they are mainly used in high-end scenarios such as aerospace and military applications.

In terms of industrial rhythm, we are currently making breakthroughs in mass production along two routes: thin films and composite materials, while the substrate route is a longer-term goal.

Nvidia is not the only player betting on diamond. AMD's high-end graphics cards have begun testing diamond heat dissipation solutions. The world's first Nvidia H200 server equipped with diamond cooling technology has been delivered for commercial use. Akash Systems has also launched a diamond cooling server powered by AMD MI350X GPUs. Leading overseas enterprises have accumulated profound experience in single-crystal and composite heat dissipation technologies and have formed partnerships with chip and packaging factories.

In China, the moves have been equally rapid and forceful. On February 28, 2026, the domestic first 8-inch diamond heat sink production line invested by a subsidiary of Huanghe Whirlwind officially commenced operation, with a total investment of 1.2 billion yuan. The first phase equipped with 50 MPCVD devices can achieve an annual output of 20,000 pieces. Sifangda successfully developed diamond heat sinks with a thermal conductivity of more than 2000W/(m·K) in 2025, which have entered the small-batch delivery stage, and has laid out a CVD diamond project with an annual output of 25,000 pieces in Xinjiang. Lishi Diamond has fully transferred the original planned investment of over 1 billion yuan for cultured diamonds to the R&D of diamond functional materials, while Wald has developed 12-inch diamond heat dissipation wafers with high flatness.

95% of the world's synthetic diamonds are produced in China, with Henan-based enterprises being the absolute main force. A complete industrial chain and lower production costs are advantages, but the fact that core components of high-end equipment still need to be imported and the long certification cycle for chip customers are real shortcomings.

From the laboratory to mass production, every step is arduous, including the growth of large-size single crystals, the reduction of thermal resistance at the bonding interface between diamond and metal, and the improvement of processing yield. At present, most enterprises are still in the sample delivery stage, and real large-scale procurement has not yet been fully rolled out.

Diamond is known as the "ultimate cooling artifact" for AI chips essentially because its intrinsic material properties perfectly meet the extreme heat dissipation needs—excellent thermal conductivity, matched thermal expansion, electrical insulation, and high temperature resistance. Such "natural adaptability" is something that other materials can hardly possess simultaneously.

2026 is recognized by the industry as the year for the large-scale commercialization of diamond heat dissipation, and the global market is expected to surge from 50 million US dollars in 2025 to 1.2 billion US dollars. In the long run, besides AI servers, electric vehicle power chips, 6G base station power amplifiers, laser devices, and aerospace electronics may all become stages for diamond heat dissipation, and the ceiling of this track is far more than 10 billion yuan.

Of course, the industry is still in its early stages. High costs, manufacturing difficulties, slow certification, and the overheating risk of capacity expansion are all hanging questions. But the direction is clear: as chip power consumption continues to surge, the revolution in heat dissipation materials will never stop.

Besides AI chips, in which high-power fields can diamond heat dissipation really shine?

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