Constructing covalently bonded interfaces between graphene films and Al-coated Cu substrates for reduced interfacial thermal resistance

The intrinsic chemical inertness of graphene films prevents effective bonding with substrates, which leads to high interfacial thermal resistance and limits their potential in chip-level thermal management. Here, the Al-coated Cu substrate was functionalized using a silane solution, and a graphene film/Al-coated substrate interconnection structure was fabricated by combining it with graphene films functionalized with a mixed acid solution. The thermal resistance of the graphene film/Al-coated Cu substrate interconnection structure first decreases and then increases with longer silane functionalization time, reaching a minimum of 3.36 ± 0.16 mm 2 ·K·W −1 at 30 minutes. Functionalized graphene films and Al-coated Cu substrates were integrated into chip cooling systems. Despite added thermal resistance from functionalization and Al-coating, carboxyl-silane interconnects maintained significantly lower chip temperatures across varying voltages compared to conventional thermal tape. These results provide valuable insights for optimizing interface bonding and heat transfer in electronic systems, which helps improve device thermal performance.