Micro-Extrusion Printhead With Nozzle Valves

Abstract

A solar cell extrusion printing system includes a printhead assembly having one or more elongated valve structures that are adjustably disposed adjacent to the outlet orifices of selected nozzle channels, and a valve control device for controlling the position of the valve structures to facilitate controllable ink flow through selected nozzle channels of the printhead assembly during the gridline printing process. The printhead assembly defines an elongated opening (e.g., a slot or hole) that that intersects (i.e., passes through) each of the selected nozzle channels, and an elongated member is movably disposed in the slot and is selectively movable between a first (opened) position, in which the valve structure extrusion material is passed by the valve structure through the nozzle channel and out of the printhead, and a closed position, in which the extrusion material is blocked by the valve structure and prevented from passing through the nozzle channel.

1 . A method for forming a plurality of parallel gridlines on a target substrate using a printhead assembly, the printhead assembly including a reservoir for receiving one or more materials from a material feed system, a plurality of elongated nozzle channels, each nozzle channel extending between said reservoir and a corresponding nozzle outlets, where at least one valve structure is adjustably disposed adjacent to the nozzle outlets of each of said plurality of elongated nozzle channels, wherein the method comprises:
 controlling said at least one valve structure such that said at least one valve structure closes all of said plurality of nozzle channels, whereby said one or more materials are prevented by said at least one valve structure from passing from the reservoir to the outlets of said plurality of nozzle channels;   positioning said printhead assembly over the surface of the target substrate such that the plurality of nozzle channels of the printhead assembly are disposed over the target substrate;   while moving said printhead assembly relative to said substrate, controlling said at least one valve structure to open at least one of said plurality of nozzle channels such that said one or more materials pass through the outlet of said at least one nozzle channel onto said substrate, whereby said material is deposited onto said substrate and forms one of said plurality of parallel gridlines.   
     
     
         2 . The method of  claim 1 ,
 wherein said at least one valve structure comprises an elongated member that is movably positioned inside an opening defined in said printhead, and   wherein controlling said at least one valve structure comprises sliding the elongated member inside the opening.   
     
     
         3 . The method of  claim 1 , wherein controlling said at least one valve structure to open at least one of said plurality of nozzle channels comprises:
 moving the at least one valve structure into a first position such that a first nozzle channel of said plurality of nozzle channels is opened, but a second nozzle channel of said plurality of nozzle channels remains closed, and   after a predetermined amount of time, moving the at least one valve structure into a second position such that both the first nozzle channel and the second nozzle channel are opened.   
     
     
         4 . The method of  claim 1 , further comprising controlling said at least one valve structure to close said plurality of nozzle channels after said plurality of gridlines are formed on said substrate. 
     
     
         5 . The method of  claim 4 , wherein closing said nozzle channels comprises:
 moving the at least one valve structure into a first position such that a first nozzle channel of said plurality of nozzle channels is closed, but a second nozzle channel of said plurality of nozzle channels remains opened, and   after a predetermined amount of time, moving the at least one valve structure into a second position such that both the first nozzle channel and the second nozzle channel are closed.   
     
     
         6 . The method of  claim 1 ,
 wherein said at least one valve structure comprises an elongated member having a plurality of openings that is movably positioned inside an opening defined in said printhead, and   wherein controlling said at least one valve structure comprises sliding the elongated member inside the opening such that each of the plurality of openings is aligned with a corresponding nozzle channel of said plurality of nozzle channels.   
     
     
         7 . The method of  claim 1 ,
 wherein said at least one valve structure comprises an elongated member that is movably positioned inside an opening defined in said printhead, and   wherein controlling said at least one valve structure comprises rotating the elongated member inside the opening.