The technique uses a “heat spreader” made of a copper-graphene composite, which is attached to the electronic device using an indium-graphene interface film “Both the copper-graphene and indium-graphene have higher thermal conductivity, allowing the device to cool efficiently,” says Dr Jag Kasichainula, associate professor of materials science and engineering at North Carolina State University and author of a paper on the research.
Kasichainula found that the copper-graphene film’s thermal conductivity allows it to cool approximately 25 percent faster than pure copper, which is what most devices currently use.
The paper also lays out the manufacturing process for creating the copper-graphene composite, using an electrochemical deposition process. “The copper-graphene composite is also low-cost and easy to produce,” Kasichainula says. “Copper is expensive, so replacing some of the copper with graphene actually lowers the overall cost.”
Samples of graphene composites with matrix of copper were prepared by electrochemical codeposition and copper-graphene composite films with a thickness greater than 200microns showed an improvement in thermal conductivity over that of electrolytic copper. Modeling of the experimental results indicate that the interface thermal resistance is not a limiting factor to improve the thermal conductivity of the copper-graphene composites.