Vapor deposition apparatus and process for continuous indirect deposition of a thin film layer on a substrate
View Patent ↗An apparatus and related process are provided for vapor deposition of a sublimated source material as a thin film on a photovoltaic (PV) module substrate. A deposition head is configured for sublimating a source material supplied thereto. The sublimated source material condenses onto a transport conveyor disposed below the deposition head. A substrate conveyor is disposed below the transport conveyor and conveys substrates in a conveyance path through the apparatus such that an upper surface of the substrates is opposite from and spaced below a lower leg of the transport conveyor. A heat source is configured adjacent the lower leg of the transport conveyor. The source material plated onto the transport conveyor is sublimated along the lower leg and condenses onto to the upper surface of substrates conveyed by the substrate conveyor.
1. An apparatus for indirect vapor deposition of a sublimated source material as a thin film on a photovoltaic module substrate, said apparatus comprising:
a deposition head configured for sublimating a source material supplied thereto;
a transfer conveyor disposed below said deposition head onto which the sublimated source material plates, wherein said transport conveyor is movable in an endless loop between an upper leg and a lower leg, said transport conveyor comprises a plurality of interconnected slats;
a substrate conveyor configured to convey substrates in a conveyance path through said apparatus;
said transfer conveyor movable to a position opposite to an upper surface of the substrates; and,
a heat source configured adjacent to said transfer conveyor;
wherein source material initially plated onto said transport conveyor is sublimated and transferred to the upper surface of substrates conveyed by said substrate conveyor.
2. The apparatus as in claim 1 , wherein said transport conveyor comprises an upper surface onto which the sublimated source material plates as said transport conveyor moves in said upper leg, said substrate conveyor disposed below said lower leg, and said heat source configured adjacent said lower leg.
3. The apparatus as in claim 2 , wherein said substrate conveyor moves in a direction opposite to said transport conveyor along said lower leg.
4. The apparatus as in claim 2 , wherein said substrate conveyor moves in the same direction as said transport conveyor along said lower leg.
5. The apparatus as in claim 4 , said transport conveyor further comprising a top member, said top member defining an open deposition area in said upper leg within which the source material plates onto said transport conveyor, said top member further defining a seal surface for said deposition head.
6. The apparatus as in claim 2 , wherein each of said slats has a respective flat planar outer surface and transverse edge profiles such that, in said upper leg, said outer surfaces of said slats lie in a common horizontal plane and define an uninterrupted flat deposition surface presented to said deposition head.
7. The apparatus as in claim 2 , wherein said substrate conveyor is configured directly opposite said lower leg of said transfer conveyor without intervening structure between the upper surface of a substrate carried by said substrate conveyor and said lower leg of said transport conveyor.
8. The apparatus as in claim 7 , wherein a diffusion length for sublimated source material from said lower leg of said transport conveyor to the upper surface of the substrates is from about 2 mm to about 50 mm.
9. The apparatus as in claim 1 , wherein said substrate conveyor comprises a roller conveyor.
10. The apparatus as in claim 1 , wherein said substrate conveyor comprises an endless loop conveyor having an upper leg that defines said conveyance path.
11. The apparatus as in claim 10 , wherein said endless loop conveyor comprises a plurality of interconnected slats, each of said slats having a respective flat planar outer surface and transverse edge profiles such that said outer surfaces of said slats lie in a common horizontal plane in said upper leg and define an uninterrupted flat support surface for said substrates.