Vapor deposition apparatus and process for continuous 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 receptacle is disposed within a vacuum head chamber and is configured for receipt of a source material. A heated distribution manifold is disposed below the receptacle and includes a plurality of passages defined therethrough. The receptacle is indirectly heated by the distribution manifold to a degree sufficient to sublimate source material within the receptacle. A distribution plate is disposed below the distribution manifold and at a defined distance above a horizontal plane of a substrate conveyed through the apparatus. The distribution plate includes a pattern of holes therethrough that further distribute the sublimated source material passing through the distribution manifold onto the upper surface of the underlying substrate.
1. An apparatus for vapor deposition of a sublimated source material as a thin film on a photovoltaic (PV) module substrate, said apparatus comprising:
a deposition head;
a receptacle disposed in said deposition head, said receptacle configured for receipt of a granular source material;
a heated distribution manifold disposed below said receptacle, said distribution manifold comprising a plurality of passages defined therethrough, said receptacle indirectly heated by said distribution manifold to a degree sufficient to sublimate source material within said receptacle, wherein said distribution manifold comprises internal heating elements arranged between said passages in said manifold;
a distribution plate disposed below said distribution manifold and at a defined distance above a horizontal conveyance plane of an upper surface of a substrate conveyed through said apparatus, said distribution plate comprising a pattern of passages therethrough that further distribute the sublimated source material passing through said distribution manifold; and
a conveyor system positioned below the distribution plate and configured to convey the substrate through said apparatus.
2. The apparatus as in claim 1 , wherein said receptacle comprises transversely extending end walls and longitudinally extending side walls, said end walls spaced from said deposition head a distance such that the sublimated source material flows primarily as transversely extending leading and trailing curtains of vapor over said end walls and downwardly through said distribution manifold.
3. The apparatus as in claim 2 , wherein said passages in said distribution plate are in a pattern such that flow of the sublimated source material from said distribution manifold is uninterrupted across said distribution plate transverse to a conveyance direction of the substrate through said apparatus.
4. The apparatus as in claim 1 , further comprising a transversely extending seal at each longitudinal end of said deposition head, said seals defining an entry and exit slot for a substrate conveyed through said apparatus, said seals disposed at a distance above the surface of the substrate that is less than the distance between the surface of the substrate and said distribution plate.
5. The apparatus as in claim 1 , further comprising a movable shutter plate disposed above said distribution manifold, said shutter plate comprising a plurality of passages therethrough that align with said passages in said distribution manifold in a first position of said shutter plate to allow passage of sublimated source material through said distribution manifold, said shutter plate movable to a second position wherein said shutter plate blocks said passages in said distribution manifold to flow of sublimated material therethrough.
6. The apparatus as in claim 5 , further comprising an actuation mechanism connected to said shutter plate to move said shutter plate between said first and second positions.
7. The apparatus as in claim 1 , wherein said distribution manifold comprises an upper shell member and a lower shell member, said shell members defining internal cavities in which said heating elements are disposed.
8. The apparatus as in claim 1 , further comprising a distributor configured in a top wall of said deposition head to disperse the source material around said receptacle.
9. The apparatus as in claim 1 , further comprising a debris shield disposed between said distribution manifold and said receptacle.
10. The apparatus as in claim 1 , wherein the conveyor system comprises a conveyor disposed below said deposition head, said conveyor unit comprising a continuous loop conveyor on which the substrates are supported below said distribution plate, said conveyor configured to convey the substrates at a constant linear speed through said apparatus between an entry slot and an exit slot such that leading and trailing sections of the substrates are exposed to generally the same vapor deposition conditions within said deposition head in a direction of conveyance of the substrates through said apparatus.