Can thermal grease become a key medium for efficient heat dissipation in electronic devices?
Publish Time: 2025-11-13
In high-performance computing, 5G communication, new energy vehicle electronic control systems, and consumer electronics, the thermal management of chips and power devices directly determines product stability, lifespan, and performance limits. Thermal grease—a functional interface material with a silicone oil matrix and composite high thermal conductivity fillers—has become the most widely used and technologically mature thermal interface material (TIM) in the field of electronic heat dissipation due to its excellent thermal conductivity, electrical insulation, flexible filling ability, and long-term reliability. Although it is only a thin layer of paste, it bridges the gaps in the micrometer scale, facilitating efficient heat conduction and silently protecting the cool operation of electronic systems.
The core advantage of thermal grease lies first and foremost in its superior dual properties of thermal conductivity and electrical insulation. By uniformly dispersing alumina (Al₂O₃), boron nitride (BN), silver powder, or carbon-based thermally conductive fillers in high-purity silicone oil, a continuous thermal pathway network is formed, achieving a thermal conductivity of 1.0–8.0 W/(m·K) or even higher, significantly superior to natural interstitial media such as air (0.026 W/(m·K)). Simultaneously, both the selected fillers and the matrix possess excellent dielectric strength (typically >10 kV/mm), ensuring no breakdown in high-voltage circuits, making it suitable for applications with stringent electrical safety requirements, such as IGBT modules, power adapters, and LED drivers.
Its flexible and malleable physical properties allow it to perfectly adapt to microscopically uneven surfaces. Even after precision machining, gaps of several micrometers to tens of micrometers still exist between heat-generating chips such as CPUs, GPUs, or power MOSFETs and the metal base of heat sinks. Thermal grease, with its low elastic modulus and high ductility, can fully wet the interface under assembly pressure, displacing air, filling unevenness, and significantly reducing contact thermal resistance. This "self-adaptive filling" capability is unmatched by rigid thermal pads or phase change materials, making it particularly suitable for applications requiring high flatness or frequent disassembly and reassembly.
Long-term stability and environmental adaptability are equally outstanding. High-quality thermal grease uses high-viscosity index silicone oil and antioxidant additives to effectively suppress the "pump-out effect" and cracking at high temperatures, maintaining stable performance over a wide temperature range of -50℃ to +200℃. After 1000 hours of high-temperature aging testing, thermal conductivity decays by less than 10%, ensuring continuous and efficient heat dissipation throughout the equipment's lifespan. Some high-end models also feature low volatility (<1%), non-corrosiveness, and halogen-free properties, complying with RoHS, REACH, and UL certification requirements, making them suitable for high-reliability applications such as medical and aerospace.
Ease of application further enhances its engineering value. The paste-like form facilitates automatic dispensing or manual application, with controllable thickness (typically 0.05–0.2mm), requiring no pre-forming or curing time, and is ready for use immediately after assembly. Compared to high thermal conductivity solutions like liquid metals, thermal grease offers safer operation, controllable cost, and strong compatibility, eliminating concerns about short-circuit risks and making it an ideal choice for balancing performance, safety, and economy.
At a deeper level, thermal grease embodies the ultimate focus of thermal management technology on the "microscopic interface." With Moore's Law slowing down, chip performance improvements increasingly rely on breakthroughs in heat dissipation bottlenecks. Optimizing the interface by even one micrometer can result in a reduction of several watts in thermal resistance, thereby unlocking more of the processor's performance potential. From smartphone SoCs to data center server CPUs, from electric vehicle OBCs to photovoltaic inverters, thermal grease remains an indispensable "invisible hero" in the hands of thermal design engineers.
Furthermore, the product offers a high degree of customization. By adjusting the type of filler, particle size distribution, and volume fraction, it can precisely match the different application scenarios' requirements for thermal conductivity, viscosity, hardness, and dielectric properties. For example, boron nitride systems are suitable for high-frequency circuits to avoid signal interference, while silver-filled types are used in scenarios requiring ultra-high thermal conductivity but allowing electrical conductivity.
In conclusion, thermal grease is no longer just an auxiliary material, but a crucial functional medium in electronic thermal management systems, bridging the gap between hot and cold environments. Based on silicone oil, it carries thermal conductivity; with fillers as bridges, it connects hot and cold regions; and with its flexibility, it bridges microscopic gaps. When a chip remains cool under heavy load, it is precisely this thin layer of thermal grease that silently and efficiently transfers heat—this seemingly ordinary paste is actually the "cooling cornerstone" for the reliable operation of modern electronic devices.
