Thermal Grease for Low Thermal Resistance Interfaces
Haktak supplies thermal grease and thermal paste materials for electronics assemblies that need excellent surface wetting, thin bond lines and stable heat transfer between components and heat sinks, housings or metal spreaders.
What Is Thermal Grease?
Thermal grease, also called thermal paste or thermal compound, is a soft thermally conductive material applied between a heat source and a cooling surface. Its main job is to wet microscopic surface roughness, displace air and reduce contact resistance at thin interfaces.
Improves surface contact
Even polished metal surfaces contain small gaps and roughness. Thermal grease fills those microvoids so heat can move more efficiently across the interface.
Works at thin bond lines
Thermal grease is most effective when the surfaces are flat, pressure is controlled and the material layer remains thin.
Supports reworkable assemblies
Because it usually does not cure into a hard bond, thermal grease is useful when serviceability, replacement or inspection may be required.
Where Thermal Grease Is the Right Choice
Flat, Mated Surfaces
Thermal grease is well suited for machined heat sinks, metal lids, module bases and housings where the real gap is small and clamping pressure is available.
Low Interface Resistance
At thin bond lines, grease can provide excellent wetting and low thermal contact resistance, often outperforming thicker pads in flat interfaces.
Rework and Maintenance
Thermal grease is useful for devices that may be opened, repaired, replaced or reassembled, such as heat sinks, power modules and serviceable electronics.
Thermal Grease Applications
CPUs and Computing Hardware
Used between processors, lids, heat sinks and cold plates where thin interfaces and strong surface wetting are needed.
Power Electronics
Supports heat transfer from power modules, MOSFETs, IGBTs, converters and drivers to metal bases or housings.
LED and Lighting
Helps reduce thermal resistance between LED boards, aluminum substrates and heat spreaders in lighting systems.
Telecom and Industrial Devices
Used in communication modules, control units, sensors and rugged electronics requiring serviceable thermal contact.
Thermal Grease vs Pad vs Gap Filler vs Adhesive
| Material | Best Use | Strengths | Watch Points |
|---|---|---|---|
| Thermal grease | Thin interfaces between flat, clamped surfaces. | Excellent wetting, low contact resistance, reworkable application. | May pump out, dry out, bleed oil or require careful thickness control. |
| Thermal pad | Controlled gap filling, insulation and easy assembly. | Clean handling, defined thickness, good dielectric options. | Higher thickness can increase thermal resistance in flat interfaces. |
| Liquid gap filler | Variable gaps, automated dispensing and complex surfaces. | Conforms to uneven gaps and reduces die-cut pad complexity. | Requires dispensing and cure/process control. |
| Thermal adhesive | Interfaces needing heat transfer plus mechanical bonding. | Combines fixation and thermal transfer. | Stress, cure, bond strength and reworkability need careful design. |
How to Apply Thermal Grease Reliably
Clean the surfaces
Remove oil, dust, oxide residue and old compound so the grease can wet the surface consistently.
Control application volume
Use a repeatable dot, line, stencil, screen print or dispensing method to avoid excessive thickness.
Apply the right pressure
Clamping force and surface flatness help spread the grease and reach the intended bond line.
Validate aging behavior
Check thermal impedance, pump-out, oil bleed and dryness after temperature cycling and operating exposure.
Need a Thermal Grease Matched to Your Interface?
Send your assembly details, target thermal performance, bond line, operating temperature and application process. Haktak can help recommend a standard material or adjust viscosity, thermal performance and reliability behavior for your project.
Thermal Grease FAQ
Is thermal grease the same as thermal paste?
Yes, thermal grease, thermal paste and thermal compound are often used to describe soft paste-like thermal interface materials for thin bond line applications.
When should I choose thermal grease instead of a thermal pad?
Choose thermal grease when surfaces are flat, the gap is very thin, clamping pressure is available and low contact resistance is the priority.
Can thermal grease fill large gaps?
Thermal grease is not ideal for large gaps. For larger or variable gaps, thermal pads or liquid gap fillers are usually more appropriate.
What causes thermal grease pump-out?
Pump-out can be caused by thermal cycling, vibration, CTE mismatch, excessive thickness or an unstable formulation. It should be validated under real operating conditions.
Is thermal grease electrically insulating?
Many thermal greases are electrically insulating, but electrical properties vary by formulation. Dielectric performance should be confirmed for power electronics and high-voltage assemblies.