Entegris and Element Six develop bonded diamond for GPU and RF cooling

Entegris and Element Six are developing bonded synthetic diamond structures for GPU and RF packages, combining diamond materials with surface preparation and bonding processes. Their partnership covers both single crystal and polycrystalline diamond, with wafer level and heterogeneous integration among the proposed manufacturing routes.^[1][2]

Heat from the semiconductor must cross the bond before it reaches the diamond, so thermal resistance at that boundary can limit how much benefit the material provides. Voids interrupt contact, while an intermediate layer may simplify bonding at the expense of a poorer thermal path. Even highly conductive diamond cannot compensate for a dominant resistance elsewhere in the stack.

To form a consistent interface, the process must control surface flatness, roughness and chemistry across the area being joined. It then has to preserve that contact as the materials expand by different amounts during operation. Repeated temperature cycling loads the bond, which means the thermal performance measured on a fresh sample may change if stress damages the interface.

The partners plan engineered surfaces and bonded technologies for different device architectures, retaining both crystal forms rather than committing to one structure. An RF device with a concentrated hotspot and a large compute die present different heat spreading geometries, affecting diamond placement, dimensions and the cost of the assembly. Their programme is intended to accommodate those differences.^[2]

Entegris has separately acquired Advanced Abrasives, adding diamond abrasive consumables for polishing hard substrates to its SiC processing materials. Its existing offering includes slurries, pads, cleaning and surface conditioning, and it plans a new Taiwan manufacturing line for the expanded SiC range. Exploratory work on thermal interface materials will continue in the US.^[1]

Those consumables support the preparation of surfaces for further processing, while the Element Six partnership develops the bonded thermal structures. Neither company has published thermal resistance results from an assembled package or performance after reliability testing. Until those measurements are available, the bulk conductivity of diamond supports the material choice but cannot quantify the reduction in device temperature.

Sources

1. Entegris, Advanced Abrasives acquisition and Element Six partnership, 3 November 2026
2. Element Six and Entegris, diamond integration scope for GPU and RF packages, 3 November 2026

Copper heat pipes and an aluminium heatsink. Illustrative cooling hardware, not the bonded diamond assembly. Photo: SHOX ART / Pexels. Photo source. Free Pexels licence.