Thermal paste with a cool solution for PCs

A US materials engineer has developed a thermal paste that could help solve the problem of overheating in high-performance PCs and other electronic devices.

According to Professor Deborah Chung, a materials researcher at the University of Buffalo, New York State, her carbon-filled organic material can produce better results than expensive materials such as carbon nanotube-based pastes.

‘Heat dissipation is the most critical problem in the electronics industry because it limits the performance, speed and further miniaturisation of microelectronics,’ said Chung.

To prevent a microprocessor from overheating, leading to burn-out, a heat sink must be placed on it. The heat sink itself is made of an extremely low heat-resistant material with a large surface area, and a fan blows air across it, keeping the processor cool.

To ensure the maximum amount of heat is removed, the processor and sink have a layer of conductive thermal paste placed between them, which are currently made from silicone containing materials such as silver or aluminium oxide. Researchers have recently been experimenting with pastes containing diamonds and carbon nanotubes to improve heat removal.

Chung’s paste is made from carbon black, a material used in tyres and rubber manufacturing. The carbon is dispersed in a mixture of polyethylene glycol and dissolved ethyl cellulose.

When tested against solder made from tin, lead and antimony, the paste’s thermal conductive ability was a third better. Solder has better conductivity than commercial pastes but is not commonly used as it must be heated to be applied. The paste also out-performed materials containing carbon nanotubes and diamonds.

Chung said the material also had potential for improving the efficiency of heat pipes that draw geothermal energy from the ground.