Web based chemical bath deposition apparatus

Abstract

Disclosed are methods and systems for processing a web. The web ( 402 ) has a first surface, a second surface opposite the first surface, and includes a magnetic material. An example system includes a processing bed ( 202 ) configured to support the web while the first surface of the web undergoes one or more processing steps. The system also includes magnets ( 300 ) positioned relative to the processing bed so as to exert a magnetic force on the web that pulls the center of the web ( 403 ) toward the processing bed. The system further includes a conveyor belt ( 404 ) configured to move the web over the processing bed ( 202 ). The conveyor belt has a first contact surface and a second contact surface opposite the first contact surface. The first contact surface is configured to contact the second surface of the web, and the second contact surface is configured to contact the processing bed.

1 . A system for processing a web, wherein the web has a first surface, a second surface opposite the first surface, and comprises a magnetic material, the system comprising:
 a processing bed, wherein the processing bed is configured to support the web while the first surface of the web undergoes one or more processing steps, and wherein the processing bed includes a center portion having a flat surface and side portions having curved surfaces;   a plurality of magnets, wherein the plurality of magnets are positioned relative to the processing bed so as to exert a magnetic force on the web that pulls the web toward the processing bed, and wherein the magnetic force is sufficient to shape the web so that the web substantially conforms to the flat surface and curved surfaces of the processing bed; and   a conveyor belt configured to move the web over the processing bed while the web is shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, wherein the conveyor belt has a first contact surface and a second contact surface opposite the first contact surface, wherein the first contact surface is configured to contact the second surface of the web, and wherein the second contact surface is configured to contact the processing bed.   
     
     
         2 . The system of  claim 1 , wherein the first contact surface of the conveyor belt is configured to apply traction to the second surface of the web such that the web moves along with the conveyor belt, and wherein second contact surface of the conveyor belt is configured to slide over the flat surface of the processing bed. 
     
     
         3 . The system of  claim 1 , wherein the magnets are embedded in the processing bed. 
     
     
         4 . The system of  claim 1 , wherein the curved surfaces of the processing bed extend upwardly from opposite sides of the flat surface of the processing bed. 
     
     
         5 . The system of  claim 1 , wherein the web has a trough shape when shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, and wherein the trough shape is capable of holding a fluid on the first surface of the web while the first surface of the web undergoes the one or more processing steps. 
     
     
         6 . The system of  claim 5 , further comprising:
 a fluid delivery apparatus positioned above the processing bed, wherein the fluid delivery apparatus is configured to deliver one or more chemicals in fluid form onto the first surface of the web while the web has the trough shape.   
     
     
         7 . The system of  claim 6 , further comprising:
 a fluid stirring apparatus positioned above the processing bed, wherein the fluid stirring apparatus is configured to stir the one or more chemicals in fluid form on the first surface of the web while the web has the trough shape.   
     
     
         8 . The system of  claim 1 , wherein the processing bed comprises at least two sections heated to different temperatures. 
     
     
         9 . The system of  claim 8 , further comprising:
 at least one thermal divider disposed between the at least two section of the processing bed and configured to thermally isolate the two section from each other.   
     
     
         10 . The system of  claim 1 , wherein the one or more processing steps relate to fabrication of photovoltaic cells. 
     
     
         11 . A method for processing a web, wherein the web has a first surface, a second surface opposite the first surface, and comprises a magnetic material, the method comprising:
 supporting the web using a processing bed while the first surface of the web undergoes one or more processing steps, wherein the processing bed includes a center portion having a flat surface and side portions having curved surfaces;   applying a magnetic force on the web using a plurality of magnets positioned relative to the processing bed so as to pull the web toward the processing bed, wherein the magnetic force is sufficient to shape the web so that the web substantially conforms to the flat surface and curved surfaces of the processing bed; and   moving the web over the processing bed using a conveyor belt while the web is shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, wherein the conveyor belt has a first contact surface and a second contact surface opposite the first contact surface, wherein the first contact surface is configured to contact the second surface of the web, and wherein the second contact surface is configured to contact the processing bed.   
     
     
         12 . The method of  claim 11 , further comprising:
 delivering one or more chemicals in fluid form onto the first surface of the web while the web moves over the processing bed; and   stirring the one or more chemicals in fluid form on the first surface of the web using an array of fans without contacting the one or more chemicals.   
     
     
         13 . The method of  claim 11 , wherein moving the web over the processing bed using comprises:
 applying traction by the first contact surface of the conveyor belt to the second surface of the web such that the web moves along with the conveyor belt, wherein second contact surface of the conveyor belt is configured to slide over the flat surface of the processing bed.   
     
     
         14 . The method of  claims 11  wherein the substrate comprises a stainless steel support and an absorber layer and the chemical fluids comprise precursors to Cadmium sulfide. 
     
     
         15 . An apparatus for processing a web, wherein the web has a first surface, a second surface opposite the first surface, and comprises a magnetic material, the apparatus comprising:
 a plurality of magnets embedded in a processing bed configured to support the web, wherein the processing bed comprises a center portion having a flat surface and side portions having curved surfaces that extend upwardly from opposite sides of the flat surface of the processing bed, and wherein the plurality of magnets are configured to apply a magnetic force on the web that pulls the web toward the processing bed to shape the web into a trough shape that substantially conforms to the flat surface and curved surfaces of the processing bed; and   a conveyor belt configured to move the web over the processing bed while the web is shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, wherein the conveyor belt has a first contact surface and a second contact surface opposite the first contact surface, wherein the first contact surface is configured to contact the second surface of the web, and wherein the second contact surface is configured to contact the processing bed.   
     
     
         16 . The apparatus of  claim 14 , further comprising:
 a fluid delivery device positioned above the processing bed and configured to deliver one or more chemicals in fluid form onto the first surface of the web while the web has the trough shape, wherein the trough shape is capable of holding the one or more chemicals on the first surface of the web.   
     
     
         17 . The system of  claim 3 , wherein
 the curved surfaces of the processing bed extend upwardly from opposite sides of the flat surface of the processing bed; and   the web has a trough shape when shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, and wherein the trough shape is capable of holding a fluid on the first surface of the web while the first surface of the web undergoes the one or more processing steps.   
     
     
         18 . The system of  claim 17 , wherein the processing bed comprises at least two sections heated to different temperatures; and
 the system further comprises at least one thermal divider disposed between the at least two section of the processing bed and configured to thermally isolate the two section from each other.   
     
     
         19 . The method of  claim 12 , wherein moving the web over the processing bed using comprises:
 applying traction by the first contact surface of the conveyor belt to the second surface of the web such that the web moves along with the conveyor belt, wherein second contact surface of the conveyor belt is configured to slide over the flat surface of the processing bed.   
     
     
         20 . A system for processing a web, wherein the web has a first surface, a second surface opposite the first surface, and comprises a magnetic material, the system comprising:
 a processing bed, wherein the processing bed is configured to support the web while the first surface of the web undergoes one or more processing steps, and wherein the processing bed includes a center portion having a flat surface and side portions having curved surfaces;   a plurality of magnets, wherein the plurality of magnets are positioned relative to the processing bed so as to exert a magnetic force on the web that pulls the web toward the processing bed, and wherein the magnetic force is sufficient to shape the web so that the web substantially conforms to the flat surface and curved surfaces of the processing bed;   wherein the web has a trough shape when shaped by the magnetic force to substantially conform to the flat surface and curved surfaces of the processing bed, and wherein the trough shape is capable of holding a fluid on the first surface of the web while the first surface of the web undergoes the one or more processing steps; and   wherein the system further comprises   a fluid delivery apparatus positioned above the processing bed, wherein the fluid delivery apparatus is configured to deliver one or more chemicals in fluid form onto the first surface of the web while the web has the trough shape; and   a fluid stirring apparatus positioned above the processing bed, wherein the fluid stirring apparatus is configured to stir the one or more chemicals in fluid form on the first surface of the web while the web has the trough shape.