THERMALLY CONDUCTIVE GREASE
- Silicone or silicone-free
- Pre-applicable printable or dispensable
Thermal greases are very commonly used thermally conductive materials.
The liquid or paste-like greases, based on silicone or non-silicone polymers, fill unavoidable air pockets caused by roughness and convex or concave unevennesses between the power component and the heat sink.
As a result, they enable more efficient heat transfer by minimizing thermal contact resistance, with the layer thickness (bondline) being very thin in the two-digit micrometre range.
The composition of thermal greases depends on the application. To achieve high thermal conductivities (1 to 8 W/mK and more) they are filled with thermally conductive particles such as ceramic powders like zinc oxide, boron nitride or aluminium oxide or metal powders, silver particles or carbon, graphite flakes.
Their disadvantage is that they are permanently fluid (viscosities of 10 and 10,000 mPas at densities of 2 to 4 g/cm³) and can only be applied safely in a process with great effort, e.g., by automated stencil printing. The risk of smearing and pump-out due to heat-changing geometries (micropumping due to CTE mismatch) during operation is high.
The use in applications that are mechanically exposed to shock and vibration is critical for a robust design from a risk point of view.
They are particularly suitable for stationary applications, e.g. in laptops, PCs, graphics cards, game consoles, computer mainboards, CPU coolers, heat spreaders, heat pipes in electronic devices in telecommunications, power electronics or consumer electronics.
FAQ
Thermally conductive grease is a liquid or paste-like thermal interface material (TIM) based on silicone or non-silicone polymers, filled with thermally conductive particles such as zinc oxide, boron nitride, aluminium oxide or graphite flakes. It fills air pockets caused by surface roughness between power component and heat sink, minimising thermal contact resistance with a very thin bondline in the two-digit micrometre range.
Silicone-based thermal greases offer excellent temperature stability and broad chemical resistance. Silicone-free thermal greases are essential where volatile siloxanes must be avoided — in automotive paint shops, sensitive electrical contacts or applications with strict silicone restrictions. For completely silicone-free gap-filling solutions, see also our silicone-free gap fillers.
Thermal grease remains permanently fluid and can only be applied process-safely with significant effort such as automated stencil printing. The risk of smearing and pump-out due to CTE mismatch during thermal cycling is high. For a process-safe alternative with the same low thermal resistance, phase change materials offer dry pre-assembly capability. For larger gaps, gap fillers provide consistent bondline thickness without smearing risk.
HALA thermal greases achieve thermal conductivities of 1 to 8 W/mK and more, depending on the filler system used. For higher thermal conductivities without the process risks of grease, silicone gap fillers reach up to 20 W/mK with process-reliable bondline thickness. Request a free sample.
Thermal grease is particularly suitable for stationary applications with planar surfaces and tight tolerances: laptops, PCs, graphics cards, game consoles, CPU coolers, heat spreaders and heat pipe assemblies in consumer electronics, telecommunications and power electronics. It is less suitable for applications subject to mechanical shock, vibration or frequent thermal cycling.
