Diamond Heat Sink: The Ultimate Thermal Solution to Break the Thermal Barrier of 5G Chips

As the wave of 5G communication technology sweeps across the globe, the technical features of high data rate, low latency, and massive connectivity are reshaping the digital world with unprecedented depth. As the core engine of this technological revolution, every leap in 5G chip performance is accompanied by an exponential increase in power consumption and a sharp rise in heat flux density. When traditional thermal management technologies gradually reach their physical limits, diamond heat sink, hailed as the "ultimate thermal management material", is emerging prominently. With its exceptional thermal management capabilities, it provides a disruptive solution for the continuous evolution of 5G chips and becomes the key to breaking through the "thermal barrier" bottleneck.

The thermal challenges facing 5G chips are systematic and multi-dimensional. Traditional thermal solutions, such as metal heat sinks like copper and aluminum, or emerging ceramic substrates such as aluminum nitride and beryllium oxide, typically have a thermal conductivity ranging from 200 to 400 W/(m·K). Confronted with the extreme thermal load of 5G chips, these materials are increasingly struggling to meet the demand. Excessively high thermal resistance leads to a significant temperature rise from the junction to the package surface, forcing the chip to either operate at a reduced frequency—sacrificing performance—or risk overheating and failure. Therefore, finding substrates or thermal spreading materials with higher thermal conductivity to achieve rapid and efficient heat transfer from the chip junction area to the external environment has become an urgent core issue for the 5G industry.

Transforming the extraordinary properties of diamond into a thermal solution for 5G chips relies on a series of precision material preparation and integration technologies.

Direct Bonded Heat Sink: A fabricated diamond thin film is metallized (e.g., with Ti/Pt/Au) and then bonded to the backside or hotspots of the chip via eutectic bonding (e.g., Au-Sn) or transient liquid phase bonding. This is currently the most direct and effective solution, particularly suitable for high-power-density devices such as GaN High Electron Mobility Transistors (HEMTs).

GaN Epitaxy on Diamond: Directly growing GaN device layers on a single-crystal diamond substrate. This achieves the "shortest heat dissipation path" from the active region to the heat sink, delivering the highest thermal efficiency and representing one of the ultimate solutions. However, it poses enormous technical challenges, involving the precise regulation of lattice mismatch and thermal mismatch.

Diamond Composite Substrate: Depositing a CVD diamond film onto substrates such as Mo or Cu to form a composite substrate, or manufacturing diamond particle-reinforced metal matrix composites. These solutions balance excellent thermal conductivity with mechanical support, processability, and cost-effectiveness, making them suitable for cost-sensitive applications.

Embedded Microchannel Cooling: Fabricating micron-scale fluid channels inside diamond using laser or etching technology, combined with microfluidic liquid cooling, to achieve hybrid enhanced heat dissipation through convection and conduction. This approach can address heat dissipation requirements of kilowatt-level and beyond.

The advantages of diamond heat sinks are reflected in the following key aspects:

Significant Junction Temperature Reduction: Experimental data shows that replacing traditional Cu or CuW heat sinks with diamond heat sinks can reduce the junction temperature of GaN power amplifiers by more than 30%. For every 10–15°C decrease in junction temperature, the device lifespan can be approximately doubled.

Enhanced Output Power and Efficiency: Lower temperatures translate to improved carrier mobility and reduced on-resistance, enabling power amplifiers to operate at higher power levels while boosting Power-Added Efficiency (PAE). This is crucial for base station energy conservation and extending the battery life of terminal devices.

Increased Power Density and Integration: Effective heat dissipation allows for more compact chip layouts and higher power density tolerance, supporting more complex multi-functional integration and driving device miniaturization.

Guaranteed High-Frequency Stability: For 5G chips operating in the millimeter-wave band, temperature fluctuations can severely impact the stability of radio frequency (RF) performance. The excellent temperature uniformity of diamond heat sinks is key to ensuring consistent high-frequency signal quality.

From breakthroughs in materials science to innovations in packaging and integration technologies, diamond heat sinks represent a fundamental technical pathway to solving the thermal bottleneck of 5G chips. It is not merely an upgrade of thermal components, but a critical enabling technology that empowers 5G chips to break through existing performance boundaries toward higher frequencies, higher power, and greater integration. On the path to 6G and beyond, how to efficiently manage the "heat" generated by extreme computing power and communication capabilities will remain a core proposition.

CSMH uses the MPCVD method to prepare large-sized and high-quality diamonds,and currently has mature products such as diamond heat sinks, diamond wafers, diamond windows,diamond composite materials,etc.Among them,the thermal conductivity of di     amond heat sinks is 1000-2200w/（m.k）, which has been applied in aerospace, high-power semiconductor lasers, optical communication, chip heat dissipation, nuclear fusion and other fields.