Performance Enhanced Heat Spreader
Embodiments of the present invention include methods of disposing a metallic coating layer comprising a metal in an amorphous and/or fine grain microstructure over at least a portion of a surface of a pyrolytic graphite substrate, the metal comprising Nickel, Iron, a Nickel-Iron Alloy, or any combination thereof, and the grains of the metal being of 1 nm to 10000 nm in size. Embodiments of the invention also encompass the coated pyrolytic graphite articles. The coated substrate exhibits a thermal conductivity not less than the uncoated substrate.
1 . A method:
disposing a metallic coating layer comprising a metal over at least a portion of a surface of a pyrolytic graphite substrate, the metal comprising Nickel, Iron, a Nickel-Iron Alloy, or any combination thereof, and the grains of the metal being of 1 nm to 10000 nm in size, the metal being amorphous, or both.
2 . The method of claim 1 , wherein the pyrolytic graphite is highly oriented pyrolytic graphite, chemical vapor deposition deposited pyrolytic graphite, or a combination thereof.
3 . The method of claim 1 , wherein the coating is a Nanovate™ N2040 coating.
4 . The method of claim 1 , wherein the metal grain size is from 2 nm to 5000 nm.
5 . The method of claim 1 , wherein the coating comprises an alloying addition.
6 . The method of claim 5 , wherein the alloying addition is selected from the group consisting of B, C, H, O, P, S, and combinations thereof.
7 . The method of claim 1 , wherein the coating comprises solid particulate of metals; metal oxides; carbides of B, Cr, Bi, Si, W, or a combination thereof; carbon; glass; polymer materials; MoS 2 , or any combination thereof.
8 . The method of claim 7 , wherein the coating comprises up to 95% by volume solid particulates.
9 . The method of claim 1 , wherein the metallic layer coating thickness is 10 μm to 50 mm.
10 . The method of claim 1 , wherein one or more intermediate coating layers are applied before the application of the metallic coating layer.
11 . The method of claim 10 , wherein the intermediate coating layer comprises a metal, a polymer, or both a metal and a polymer.
12 . The method of claim 10 , wherein the intermediate coating layer thickness is less than the metallic coating layer thickness.
13 . The method of claim 1 , wherein the metallic coating layer covers all of the exterior surface of the substrate.
14 . The method of claim 1 , wherein the metallic coating layer covers only a portion of the exterior surface of the substrate.
15 . The method of claim 1 , wherein the substrate coated with the metallic coating layer exhibits a thermal conductivity not less than the uncoated substrate.
16 . The method of claim 1 , wherein the substrate coated with the metallic coating layer exhibits a thermal conductivity of about 105% of the thermal conductivity of the uncoated substrate, or of not less than 105% of uncoated substrate and also not more than 250% of the uncoated substrate.
17 . The method of claim 1 , wherein the substrate coated with the metallic coating layer exhibits a thermal conductivity of about 110% of the thermal conductivity of the uncoated substrate, or of not less than 110% of uncoated substrate and also not more than 250% of the uncoated substrate.
18 . The method of claim 1 , wherein the substrate coated with the metallic coating layer exhibits a thermal conductivity of about 115% of the thermal conductivity of the uncoated substrate, or of not less than 115% of uncoated substrate and also not more than 250% of the uncoated substrate.
19 . The method of claim 1 , wherein the metallic coating layer has a room temperature coefficient of linear thermal expansion in all directions of less than 25×10 −6 K −1 .
20 . An article comprising:
a substrate of pyrolytic graphite;
a metallic coating layer comprising a metal deposited over at least a portion of a surface of the pyrolytic graphite substrate, the metal comprising Nickel, Iron, a Nickel-Iron Alloy, or any combination thereof, and the grains of the metal being of 1 nm to 10000 nm in size, the metal being amorphous, or both.