Deposition of nanocomposites coating on polyimide films by atmospheric pressure plasma for enhanced thermal conductivity

The increasing demand for flexible electronics has spurred the development of flexible substrates with high thermal conductivity. Herein, nanocomposite coatings based on aluminum nitride (AlN) and siloxane matrix are deposited on polyimide (PI) films by atmospheric pressure plasma for improved thermal conductivity. Commercially available aluminum nitride powders are incorporated into methyltrimethoxysilane (MTMS) pre-cursor to form nanocomposite coatings at atmospheric pressure. The evolution of the as-prepared coatings is systematically investigated upon the variations of the deposition time. The smooth surface is transformed into a rough surface with spherical nanoparticles, and the silicon containing functional groups with AlN nanoparticles are introduced into the surface. After 6 min deposition, the surface energies of the PI film can be improved to 32.8 mJ/m2, and the thermal conductivity can be enhanced to 1.68 W/mK with a coating hardness of 2H. The results demonstrate that the nanocomposite coatings prepared by plasma deposition are an efficient way to modify flexible materials with improved thermal conductivity.