Thermally conductive and protective coating for electronic device

An electronic device, comprising:

• a substrate
• a thin film circuit layer disposed over the substrate;
• and
• a protective coating layer disposed over the thin film circuit layer, the protective coating layer comprising:
• a first coating;
• and
• two layers of a second coating contacting the first coating, including a first layer of the second coating disposed below the first coating and contacting the film circuit layer, and a second layer of the second coating disposed over the first coating,
• wherein
• the first coating and the second coating are thermally conductive, each of the first coating and the second coating has a cross-plane thermal conductivity in a direction normal to a respective coating surface equal to or higher than 0.5 W/(m*K),
• the first coating and the second coating are each made of a material comprising the same chemical element or elements but having differing crystal structure and amorphous structure, different crystal lattice arrangements, different crystalline orientations, or a combination of different crystal lattice arrangements and crystalline orientations,
• the first coating has a hardness lower than that of the second coating, and
• the cross-plane thermal conductivity of at least one of the first coating and the second coating is higher t ha n a respective in-plane thermal conductivity in a direction parallel to the respective coating surface.