Application of Diamond Materials in AI Server GPU Liquid Cooling

(For GPUs with 700–2000W Power Consumption)

As AI server GPU power densities surge to 700–2000W, conventional copper and aluminum cold plates have reached their thermal limits. Single-crystal / polycrystalline diamond, diamond‑copper and diamond‑aluminum composites have become core materials for direct cooling, microchannel cold plates, immersion cooling, and two‑phase evaporative cooling.

They are applied across six major modules:

I. GPU/CPU Chip‑Level Heat Spreaders

Taiwan terminology: Diamond Heat Spreader, CVD Polycrystalline Heat Spreader, Single‑Crystal Diamond Vapor Chamber

Applications: Direct Liquid Cooling (DLC), Chip Backside Liquid Cooling

1.Polycrystalline CVD Diamond Heat Spreaders

Thermal conductivity: 1500–1800 W/m·K

Mounted on the backside of GPUs and HBM memories to rapidly homogenize chip hotspots and eliminate local overheating.

When integrated with liquid cooling cold plates, chip junction temperatures are reduced by 10–24°C, significantly reducing frequency throttling.

Suitable for single‑phase liquid cooling plates and rack‑mounted liquid cooling systems.

2.Single‑Crystal Diamond (SCD) Wafer Substrates

Thermal conductivity: 2000–2200 W/m·K

Used directly as AI chip substrates, enabling heat to transfer straight from the die to the liquid cooling interface.

Thermal resistance reduced by over 50%, supporting ultra‑high‑power chips exceeding 3000W.

Enables near‑atmospheric water phase‑change evaporative cooling, cutting data center water consumption by 55 times.

3.Key Advantages

Diamond has a coefficient of thermal expansion (CTE ≈ 1.1 ppm/K) closely matched to silicon, preventing warpage or delamination during thermal cycling.

As an intrinsic electrical insulator, it eliminates the need for extra insulating layers that add thermal resistance.

II. Diamond Composite Liquid Cooling Cold Plates (Microchannel Cold Plates)

Taiwan terminology: Diamond‑Copper Liquid Cooling Plate, Diamond Composite Microchannel Cold Plate

English: Diamond‑Copper Composite Liquid Cold Plate

1.Diamond‑Copper (Diamond‑Cu) Cold Plates

Thermal conductivity: 600–800 W/m·K, 1.5–2× that of pure copper.

Capable of precision microchannel machining for integration into AI server liquid cooling modules.

Mass‑adopted in Wiwynn and Sugon megawatt‑class liquid cooling racks, improving overall system thermal efficiency by 80%.

Single racks support high‑density computing clusters exceeding 60kW.

2.Diamond‑Silicon Carbide (Diamond‑SiC) Composite Cold Plates

CTE perfectly matched to silicon, eliminating thermal stress and cracking.

Designed for premium AI accelerators above 2000W under continuous full‑load operation.

Resistant to corrosion and deformation in long‑term liquid cooling environments.

3.Value Benefits

Density is only 67% that of copper, reducing server weight and solving high‑density rack loading constraints.

Cold plate volume is reduced at equivalent cooling capacity.

III. Diamond Thermal Modules for Immersion Liquid Cooling

Taiwan terminology: Immersion Cooling Diamond Thermal Module, Phase‑Change Immersion Heat Sink

In immersion‑cooled racks, GPUs are equipped with external diamond‑copper vapor chamber blocks submerged in dielectric coolant.

These modules rapidly spread heat to the fluid interface, enhancing solid‑liquid heat exchange efficiency and lowering PUE below 1.1, meeting green AI data center standards.

When paired with two‑phase immersion cooling, diamond uniformly elevates the chip heat surface temperature to enable stable boiling phase change of coolant.

Thermal dissipation performance improves by 10–100×, eliminating the need for high‑flow liquid cooling loops.

IV. Miniature Diamond Heat Spreaders for HBM High‑Bandwidth Memory

AI server HBM memories feature dense stacking and severe local hotspots, while conventional copper heat spreaders are too bulky.

Ultra‑thin polycrystalline diamond sheets attached to the backside of memory stacks, combined with side‑flow liquid cooling channels, resolve overheating‑induced throttling and increased access latency.

V. Thermal Bridges and Vapor Chamber Connectors for Liquid Cooling Systems

Taiwan terminology: Diamond Thermal Bridge, Diamond Vapor Chamber Pad

Diamond‑copper transition blocks placed between GPU dies and liquid cooling cold plates, replacing conventional copper heat blocks to reduce total interface thermal resistance and reduce reliance on thermal interface materials (TIM).

For multi‑GPU parallel liquid cooling manifolds: diamond composite materials are used as vapor chamber distribution plates to balance temperature differences across GPUs, preventing single‑card overheating from limiting overall cluster performance.

VI. Liquid Cooling Substrates for High‑Power PSUs and Switches

High‑voltage DC power supplies and network switches in AI racks consume several kilowatts.

Diamond composite substrates integrated into liquid cooling modules resolve heat accumulation in power MOSFETs, ensuring stable long‑term operation of rack power delivery systems.