NANODIAMOND THICK FILMS FOR THERMAL MANAGEMENT

The decreasing size of modern electronic devices, combined with increasing performance demands, leads to higher heat density in smaller spaces. Efficient diffusion or extraction of this thermal energy may limit the miniaturization of these heat-generating electronics. To enable denser packaging of higher performance chips, innovations are required in thermally conductive materials, liquid or liquid-vapor based heat removal methods, and thermal buffering materials. Diamond has the highest thermal conductivity among all known materials while being uniquely electrically insulating. This is due to its strong covalent bonds, which facilitate high phonon-based thermal conduction, unlike the electron-based thermal conduction found in metals like copper. However, the use of macroscale diamond as a thermal conduction material in electronics is limited by its cost and machinability. In contrast, detonation nanodiamond is relatively inexpensive, produced from a TNT/RDX explosion in an oxygen-poor environment. Furthermore, electrophoretic deposition allows these nanodiamonds to be incorporated into electronics as conformal coatings. Here, we present advancements in the electrophoretic deposition of nanodiamond thick films, their thermal conductivity characterization, and potential applications. This includes suspending nanodiamonds in a solution with high zeta potential, improving deposition chemistry and drying processes to mitigate film cracking, and performing 3-omega thermal conductivity measurements on the deposited films.