Heat-conducting polymer survives up to 200°C
1 min read
Researchers in the US have created a polymer which they say can improve the interface between silicon and heatsinks.
Created using an electropolymerisation process by a team from Georgia Tech, the patent pending material can be adhered to a range of surfaces and is able to withstand temperatures up to 200°C.
"A material like this, which could also offer higher reliability, could be attractive for addressing thermal management issues," said lead researcher Baratunde Cola. "This material could ultimately allow us to design electronic systems in different ways."
The researchers created the interface material from a conjugated polymer, polythiophene, in which aligned polymer chains in nanofibres facilitate the transfer of phonons – but without the brittleness associated with crystalline structures.
Formation of the nanofibres produces an amorphous material with thermal conductivity of up to 4.4W per meter Kelvin at room temperature.
To fabricate the material, Cola and his team covered an aluminium template containing tiny pores with an electrolyte containing monomer precursors. These were formed into hollow nanofibres by applying a voltage to the template.
After formation of the monomer chains, the nanofibers were cross-linked with an electropolymerisation process, and the template removed.
The resulting structure can be attached to electronic devices through the application of water or a solvent, which spreads the fibres and creates adhesion through capillary action and van der Waals forces.
"With the electrochemical polymerisation processing approach that we took, we were able to align the chains of the polymer, and the template appears to prevent the chains from folding into crystals so the material remained amorphous," Cola explained. "Even though our material is amorphous from a crystalline standpoint, the polymer chains are highly aligned – about 40% in some of our samples."
Though the technique still requires further development and is not fully understood theoretically, Cola believes it could be scaled up for industrial use.
The new material could even allow reliable thermal interfaces as thin as 3µm, he said.
