Heat spreading coating for electronic assemblies

An electronic assembly with heat spreading coating comprising:

• a printed circuit board (PCB) having electric conducting traces and at least one heat producing electronic component;
• an electrically isolating polymeric coating applied over the electric conducting traces and the at least one heat producing electronic component, wherein the polymeric coating comprises parylene, and wherein the polymeric coating at least partially covers the PCB, and wherein the electrically isolating polymeric coating conforms with an irregular structure of the PCB;
• a first heat spreading layer, applied over the polymeric coating, comprises:
• at least one heat spreading zone selected from the group consisting of:
• a plurality of graphene nano-platelets, a plurality of graphene particles, a plurality of boron-nitride particles, a plurality of graphene flakes, a plurality of boron-nitride flakes, at least one graphene sheets, and combination thereof;
• and
• a binder,
• wherein the electrically isolating polymeric coating adheres to the PCB and covers the electric conducting traces and the at least one heat producing electronic component, and the first heat spreading layer conforms to the irregular structure of the polymeric coating.