When it comes to maintaining optimal performance and preventing overheating in electronic devices, thermally conductive grease plays a vital role. Thermal paste improves heat transfer between CPUs/GPUs and heatsinks by filling tiny gaps that air cannot. But what exactly is thermally conductive grease, and why does it matter so much in cooling systems? In this article, we’ll explore the purpose, benefits, and importance of thermally conductive grease in effective thermal management.
What is Thermally Conductive Grease?
Thermal paste is a material applied between a heat-producing component, like a CPU or GPU, and its cooler. It helps improve heat transfer by filling tiny air gaps, which don’t conduct heat well, with a substance that moves heat much more efficiently.
Pros
- Great at improving heat transfer.
- Fits uneven surfaces perfectly.
- Easy to apply.
Cons
- Can be messy.
- May dry out or lose performance over time.
- Metal-based thermal pastes can cause short circuits if applied incorrectly.
Thermal paste is key to keeping electronics cool. Apply a thin, even layer to maximize heat transfer and protect your components.
How Thermally Conductive Grease Works
- Microscopic surface imperfections – Even though the CPU and heatsink look smooth, under a microscope, they’re full of tiny bumps and dents. These uneven spots stop the surfaces from touching completely.
- Air gaps block heat – The gaps between them trap air, which is a terrible heat conductor—over 100 times worse than thermal grease and thousands of times worse than metals like copper. This slows down heat transfer.
- Filling the gaps – Thermal grease flows into those tiny spaces, pushing out the air. This increases real surface contact and makes heat flow more easily.
- Heat transfer process – Heat moves from the CPU chip to its metal cover (IHS), then through the thermal grease into the heatsink or cold plate, where it’s carried away by air or liquid cooling.
Advantages of Thermally Conductive Grease
- Efficient Heat Transfer
Contains materials like aluminum oxide or boron nitride to keep devices cool and stable.
- Flexible and Easy to Apply
Can be brushed, spread, or dispensed automatically. You can adjust the layer thickness to suit different cooling needs.
- Wide Temperature Range
Functions reliably from –50 °C to +200 °C, with some types handling even higher temperatures.
- Electrically Insulating
Most thermal greases prevent electrical shorts, protecting sensitive electronics.
- Non-Curing and Maintenance-Friendly
Stays soft over time, making it easy to remove and reapply when upgrading or servicing components.
- Durable and Environmentally Friendly
Resists aging, oxidation, and corrosion. Many meet environmental standards like RoHS.
Thermal grease not only transfers heat but also ensures your cooling system runs efficiently, safely, and reliably for both everyday industrial applications.
Popular Thermally Conductive Grease Products
- TG-N909 Non-Silicone Thermal Paste
TG-N909 is a high-performance, non-silicon thermal paste ideal for heat-sensitive applications.
Key Features
- High Thermal Conductivity (9 W/m·K): Efficiently transfers heat from high-wattage components.
- Silicone Oil Free: No silicone evaporation or oil precipitation.
- No Overflow & Low Thermal Resistance: Stays in place and ensures minimal heat blockage.
- Non-Silicone Base & Eco-Friendly: Safe for the environment and sensitive equipment.
Applications: CPUs, chip coolers, LEDs, optical instruments, and other silicon-sensitive electronics.
Key Benefit: Enhances heat dissipation, improves component efficiency, and extends lifespan without silicone-related issues.
- TG-AS808 / TG-S808 Thermal Paste
Key Features
- Good Leveling & No Overflow: Even spread without spilling.
- Fills Microscopic Gaps: Enhances thermal contact by filling uneven surfaces.
- Low Thermal Resistance: Minimizes heat blockage between components and heatsinks.
- Eco-Friendly: Made from organic silicon materials.
Applications: Electric locomotives, 5G servers, automated driving systems, HPC systems, CPUs, ICs, LEDs, motherboards, power supplies, heat sinks, notebooks, mobile devices, routers, AI, and IoT devices.
- TG-AS606C / S606C Thermal Paste
Key Features
- Thermal Conductivity: 5.3 W/m·K for effective heat dissipation.
- Easy Application: Can be applied in a thin layer, minimizing thermal interface thickness.
- High Stability: Maintains performance over time for moderate-power devices.
- Good Gap Filling: Effectively fills small gaps to improve heat transfer.
Applications: PCs, robots, consumer electronics, and other devices with moderate heat loads.
Key Consideration: Less suitable for high-power or hard-to-replace products, as it may dry out over time.
- TG-AS606B / S606B Thermal Paste
- Thermal Conductivity: 1.9 W/m·K, suitable for low to moderate heat dissipation.
- High Stability: Maintains performance in various electronic setups.
- Good Gap Filling: Effectively fills small contact interface gaps to reduce thermal resistance.
- Cost-Effective: Ideal for budget-conscious projects or applications that don’t require high thermal conductivity.
Applications: ICs and general electronic products with moderate heat loads and limited design space.
Key Consideration: Not suitable for high-wattage or high-performance components.
Select thermal paste considering its conductivity, application ease, long-term stability, and your system type.
How to Apply Thermal Paste Correctly
Applying thermal paste correctly helps your CPU or GPU stay cool by transferring heat efficiently to the heatsink. Follow these steps:
- Clean the Surfaces
Make sure both the CPU/GPU and heatsink are clean. Remove old thermal paste, dust, and oils using 90%+ isopropyl alcohol and a lint-free cloth or cotton swab. Clean surfaces ensure the thermal paste performs effectively.
- Apply a Thin, Even Layer
- For most CPUs, place a pea-sized dot (~0.3–0.4 ml) in the center of the CPU.
- When you attach the heatsink, the paste will spread evenly.
- For AMD Ryzen CPUs with a curved surface, use five small dots in a cross pattern to evenly cover the surface.
- Avoid Over-Application
- Too much paste can spill onto other parts and may cause short circuits if the paste is conductive.
- Use a plastic spreader or the included applicator to control the amount.
- Reapply When Needed
- Thermal paste wears out over time, which can cause an increase in temperatures.
- Reapply every 2–5 years, or sooner if your system runs hotter than usual.
- Always reapply when replacing or reseating the heatsink.
Tools You’ll Need
- Thermal Paste: High-quality brands like Noctua NT-H2 or Thermal Grizzly Kryonaut.
- Isopropyl Alcohol (90%+): For cleaning surfaces.
- Lint-Free Cloth or Cotton Swabs: For cleaning.
- Plastic Spreader (optional): For spreading paste evenly.
- Anti-Static Wrist Strap: To avoid damaging components with static electricity.
Common Mistakes to Avoid
- Too Much Paste: Creates a thick layer that reduces heat transfer.
- Avoid Metal Tools: Metal can scratch or damage the CPU/GPU surface. Use a plastic spreader or the applicator that comes with the thermal paste instead.
- Over-Tightening Screws: Can warp the heatsink and leave gaps.
