Highly Thermally Conductive and Light Weight Copper/Graphene Film Laminated composites for Cooling Applications
Paper in proceedings, 2018
A light-weight, robust and highly thermal conductive copper/graphene film laminated structure was developed as novel heat spreading materials for thermal management applications. The advantages of the copper/graphene film laminated structure lie in its ability to combine both good mechanical properties of metals and excellent thermal properties of graphene film. Graphene films (GFs) were fabricated via self-assembly of graphene oxide (GO) sheets and post-treated by high temperature graphitization and mechanical pressing. The resulted GFs show excellent flexibility and greatly improved tensile strength which is over 3 times higher than commercial PGS. The successful lamination between copper and GFs was realized by indium bonding. Thin indium layers can provide complete physical contact between copper and GFs, and thereby, minimize the contact resistance induced by surface roughness. The measured contact thermal resistance between copper and GFs bonded by indium is in the range of 2-5 Kmm(2)/W for a working temperature between 20 degrees C to 100 degrees C. This value is orders magnitude lower than other bonding methods, including direct hot pressing of copper and GFs, tape bonding and thermal conductive adhesive (TCA) bonding. By tailoring the thickness of GFs, desirable laminated composites with optimized thermal conductivity can be obtained, which offers an efficient heat dissipation solution for power driven systems.