Entrance and exit roll seal configuration for a vapor deposition system

An apparatus for vapor deposition of a sublimated source material as a thin film on discrete photovoltaic (PV) module substrates conveyed in a continuous non-stop manner through said apparatus, comprising:

• a vapor deposition head configured for receipt and sublimation of a source material, and for distributing the sublimated source material onto an upper surface of substrates conveyed through a deposition area of said apparatus;
• a roll seal configuration with at least one of an entry slot and an exit slot for the substrates conveyed through said apparatus;
• said roll seal configuration further comprising a cylinder rotatably supported at a defined gap height above a conveyance plane of the substrates such that said cylinder is not in continuous rolling contact with the substrates in a defined active semiconductor area of the substrate;
• said cylinder floatable in a vertical direction relative to the conveyance plane of the substrates such that said cylinder rolls up and over surface variations in the substrates that exceed said gap height as the substrates are conveyed under said cylinder;
• said cylinder comprising a stepped diameter with increased greater diameter bands at ends thereof, said increased diameter bands configured to roll continuously or intermittently on lateral edge portions of the substrates.