Cool-down system and method for a vapor deposition system
View Patent ↗A system for vapor deposition of a thin film layer on photovoltaic (PV) module substrates includes a system for cool-down of the vacuum chamber through which substrates are conveyed in a vapor deposition process. The cool-down system is configured with the vacuum chamber to recirculate a cooling gas through the vacuum chamber and through an external heat exchanger in a closed cool-down loop. An associated method for forced cool-down of the vacuum chamber is also provided.
1. A system for vapor deposition of a thin film layer on photovoltaic (PV) module substrates, comprising:
a vacuum chamber through which substrates are conveyed in a vapor deposition process wherein a source material is sublimated and deposited onto a surface of the substrates;
said vacuum chamber further comprising:
a vapor deposition chamber;
an entry vacuum lock station, and an exit vacuum lock station;
a conveyor configured for receipt and conveyance of individual PV module substrates through said entry vacuum lock station, said vapor deposition chamber, and said exit vacuum lock station;
a feed device configured with said vapor deposition chamber to supply source material thereto;
wherein said vapor deposition chamber further comprises a vapor deposition apparatus configured to sublimate the source material from said feed device and deposit the sublimated source material as a thin film layer onto the PV module substrates carried by said conveyor through said vapor deposition chamber; and
a cool-down system configured with said vacuum chamber to recirculate a cooling gas through said vacuum chamber, said cool-down system including a heat exchanger external to said vacuum chamber through which the cooling gas recirculates in a closed cool-down loop, wherein said cool-down system further comprises:
an intake duct connected at a first location to said vacuum chamber;
a supply duct connected at a second location to said vacuum chamber that is spaced from said first location;
a cool-down chamber external to said vacuum chamber, said intake duct and said supply duct connected to said cool-down chamber;
said heat exchanger disposed within said cool-down chamber;
a blower disposed within said cool-down chamber; and,
an inert gas supply configured to introduce the cooling gas into said closed loop cool-down system;
wherein said cooling gas is drawn through said vacuum chamber, cooled in said cool-down chamber, and recirculated back through said vacuum chamber in the closed cool-down loop.
2. The system as in claim 1 , further comprising a vacuum pump configured with said cool-down chamber.
3. The system as in claim 1 , further comprising a cooling device configured with said intake duct.
4. The system as in claim 1 , wherein said cool-down system further comprises isolation valves in said intake and supply ducts to isolate said cool-down chamber from said vacuum chamber.
5. The system as in claim 1 , wherein said inert gas supply is disposed so as introduce the inert gas into said vacuum chamber.
6. The system as in claim 1 , wherein said inert gas supply is disposed so as to introduce the inert gas into said cool-down chamber.
7. The system as in claim 1 , wherein said vacuum chamber further comprises a plurality of pre-heat modules upstream of said deposition chamber in a conveyance direction of the substrates, and a plurality of cool-down modules downstream of said vapor deposition chamber in a conveyance direction of the substrates, said closed loop cooling system comprising a supply duct connected to one of said pre-heat modules and an intake duct connected to one of said cool-down modules.
8. The system as in claim 1 , further comprising a vacuum pump configured with said cool-down chamber.