The explosion of large-model computing power has driven the power density of AI chips and third-generation semiconductor devices ever higher. Traditional copper and aluminum heat sinks have hit the ceiling of physical performance. In high-heat-flux scenarios, heat dissipation breakthroughs no longer rely on structural optimization alone-the intrinsic material performance limits have become the decisive bottleneck for the stability and service life of high-end devices. Thanks to its outstanding comprehensive physical properties, diamond is rapidly transitioning from a laboratory material to industrial application, becoming the core material reshaping the thermal management landscape of high-end chips.
Diamond's overall heat dissipation performance is exceptional, with its core advantage stemming from its unique thermal conduction mechanism. Unlike copper and aluminum, which rely on free electrons for heat transfer and have inherent limitations, diamond conducts heat through phonon transport, fundamentally breaking through the thermal dissipation ceiling of traditional metallic materials.
Single-crystal diamond achieves a room-temperature thermal conductivity of 2000–2200 W/(m·K)-5 to 6 times that of copper and more than 9 times that of aluminum. At the same time, its low coefficient of thermal expansion (1.0–1.2×10⁻⁶/K), ultra-high electrical resistivity, and low dielectric constant make it perfectly compatible with chip packaging requirements. It simultaneously addresses the three major challenges of high thermal load, thermal mismatch, and electrical interference, and is recognized as the "ultimate material" for heat dissipation in AI chips and GaN power devices.
For chip heat sinks, one must simultaneously consider thermal conductivity, structural adaptability, and mass-production cost. While pure single-crystal diamond offers extreme performance, it is difficult to process and costly to produce over large areas, making it unsuitable for large-scale manufacturing. This is the key reason why the industry has abandoned the route of universal pure diamond heat sinks and instead pivoted to prioritizing diamond composite materials.
Currently, the most industrially mature and closest to large-scale deployment is the diamond‑copper composite material. This material uses diamond particles as the reinforcing phase and copper as the matrix, combining the ultra-high thermal conductivity of diamond with the ductility and solderability of copper, achieving a balance between performance and engineering practicality. Its thermal conductivity reaches 600–1000 W/(m·K), 1.5–2.5 times that of pure copper. By adjusting the diamond volume fraction, the coefficient of thermal expansion can be precisely matched to semiconductor materials such as SiC and GaN, effectively solving the warpage and solder-joint failure issues caused by thermal mismatch in traditional copper heat sinks.
However, there is a hidden engineering barrier: the quality of the diamond‑copper interface bonding directly determines the ultimate heat dissipation performance of the finished product. Poor interfacial bonding leads to severe interfacial thermal resistance, significantly degrading thermal conductivity. Therefore, fine processes such as diamond surface modification and copper matrix alloying are core technological barriers that separate leading companies from the rest and ensure production yield-they are also the key competitive points in the industry.
The diamond industry follows two main technical routes-single-crystal and polycrystalline-with markedly different industrialization paces. Single-crystal diamond is not only an excellent heat-dissipation material but also a high-performance wide-bandgap semiconductor, offering advantages such as high breakdown voltage, strong radiation resistance, and high carrier mobility, with future potential for use in high-temperature chip fabrication. However, large-area single-crystal growth remains extremely challenging. The mainstream methods-three-dimensional growth and (tiling) expansion-have stringent requirements on seed crystal quality and deposition environments, and still suffer from issues like gaps and non-uniform growth, making near-term commercial deployment difficult.
Polycrystalline diamond produced by CVD processes, although having slightly lower thermal conductivity (1000–1800 W/(m·K)) than single-crystal diamond due to phonon scattering at grain boundaries, can be manufactured over large areas and at lower cost on a mass scale. Its thermal conductivity steadily improves with increasing grain size. Among these, microcrystalline and large-grain polycrystalline diamonds offer a good balance of performance, size, and cost, and their industrialization progress in high-end power device heat dissipation far outpaces that of high-end single-crystal products.
Currently, CVD diamond fabrication mainly relies on four types of methods, among which the MPCVD (microwave plasma chemical vapor deposition) process is the preferred choice for producing high-quality polycrystalline diamond due to its advantages of no electrode contamination, stable plasma, and controllable parameters. However, this process faces a hard equipment bottleneck: the preparation of large-area diamond films requires higher microwave power and lower microwave frequency, so the product size and output are entirely constrained by the hardware performance of the microwave generator.
This equipment limitation directly affects the entire industrial chain. High-end imported MPCVD systems are expensive and have long delivery lead times, constraining the pace of domestic capacity expansion. At the same time, domestically produced high-power MPCVD equipment is rapidly iterating and breaking the overseas technological monopoly. The speed of its mass-production deployment will directly determine the cost-reduction trajectory of diamond heat-dissipation materials, and thus whether this material can penetrate from high-end specialized applications into mainstream computing-power industries such as AI servers and accelerator cards.