Thermal interface material

• Thermal paste: Mostly used in the electronics industry, it provides a very thin bond line and therefore a very small thermal resistance. It has no mechanical strength and will need an external mechanical fixation mechanism. Because it does not cure, it is used only where the material can be contained or in thin application where the viscosity of the paste will allow it to stay in position during use.
• Thermal adhesive: As with the thermal paste, it provides a very thin bond line, but provides some additional mechanical strength to the bond after curing. Thermal glue allows thicker bond line than the thermal paste, as it cures.
• Thermal gap filler: It could be described as "curing thermal paste" or "non-adhesive thermal glue". It provides thicker bond lines than the thermal paste as it cures while still allowing an easy disassembly thanks to limited adhesiveness.
• Thermally conductive pad: As opposed to previous TIM, a thermal pad does not come in liquid or paste form, but in a solid state. Mostly made of silicone or silicone-like material, it has the advantage to be easy to apply. It provides thicker bond lines, but will usually need higher force to press the heat sink on the heat source so that the thermal pad conforms to the bonded surfaces.
• Thermal tape: It adheres to surface, requires no curing time and is easy to apply. It is essentially a thermal pad with adhesive properties.
• Phase-change materials : Naturally sticky materials, used in place of thermal pastes. Its application is similar to solid pads. After achieving a melting point of - 55-60 degrees, it changes to a half liquid status and fills all gaps between the heat source and the heat sink.
• Metal thermal interface materials : Metallic materials offer substantially higher thermal conductivity as well as the lowest thermal interface resistance. This high conductivity translates to less sensitivity to bondline thicknesses and coplanarity issues than polymeric TIMs.