Continuous web apparatus and method using an air to vacuum seal and accumulator

Abstract

A deposition apparatus includes an input spool located in non-vacuum input module, at least one vacuum process module, an accumulator, and an air to vacuum sealing mechanism. The accumulator and the sealing mechanism are configured to continuously provide a web substrate from the input spool at atmosphere into the at least one process module at vacuum without stopping the web substrate.

What is claimed is: 
     
         1 . A layer deposition method, comprising:
 passing a web substrate from an input module not under vacuum to an output module not under vacuum through an accumulator and through at least one process module under vacuum, such that the web substrate continuously extends from the input module to the output module while passing through the accumulator and the at least one process module;   removing a first roll of the web substrate from an input spool in the input module;   mounting a second roll of the web substrate on the input spool;   attaching a trailing edge of the web substrate from the first roll which is removed from the input spool to a leading edge of the web substrate from a second roll which is mounted on the input spool;   changing a length of a path of the trailing edge of the web substrate from the first roll in the accumulator during the steps of removing, mounting and attaching such that the web substrate passes through the at least one process module during the steps of removing, mounting and attaching without stopping; and   depositing at least one layer on the web substrate moving through the at least one process module during the steps of removing, mounting and attaching.   
     
     
         2 . The method of  claim 1 , wherein the at least one process module comprises a plurality of independently isolated, connected process modules, and the depositing at least one layer comprises depositing at least one different layer in each of the plurality of process modules. 
     
     
         3 . The method of  claim 2 , wherein the depositing at least one different layer in each of the plurality of process modules comprises forming a solar cell by sputtering a first electrode, a CIGS p-type absorber layer, an n-type semiconductor layer and a transparent second electrode over the substrate in corresponding process modules of the plurality of independently isolated, connected process modules without breaking vacuum during the steps of removing, mounting and attaching. 
     
     
         4 . The method of  claim 2 , wherein the step of attaching comprises welding. 
     
     
         5 . The method of  claim 2 , further comprising passing the web substrate from the accumulator to the at least one process module through an air to vacuum sealing mechanism. 
     
     
         6 . The method of  claim 5 , wherein web substrate passes through the air to vacuum sealing mechanism and the at least one process module without stopping at about the same rate before, during and after the steps of removing, mounting and attaching. 
     
     
         7 . The method of  claim 6 , wherein the accumulator increases the path length of the trailing edge of the web substrate from the first roll prior to the step of removing and gradually decreases the path length of the trailing edge of the web substrate during the steps of removing, mounting and attaching such that the trailing edge of the web substrate moves through the at least one process module at the about the same rate during the steps of removing, mounting and attaching.