Roll-to-roll electroless plating system with micro-bubble injector

Abstract

A roll-to-roll electroless plating system including a reservoir containing plating solution. A web advance system advances a web of media though the plating solution in the reservoir, wherein a plating substance in the plating solution is plated onto predetermined locations on a surface of the web of media. A distribution system injects an inert gas into the plating solution to reduce the amount of dissolved oxygen. The distribution system includes an injector having a converging tube segment, a diverging tube segment downstream of the converging tube segment, a throat formed at a junction of the converging tube segment and the diverging tube segment, and an inlet for the inert gas in proximity to the throat.

1 . A roll-to-roll electroless plating system, comprising:
 a reservoir containing plating solution;   a web advance system for advancing a web of media from an input roll through the plating solution in the reservoir to a take-up roll, wherein a plating substance in the plating solution is plated onto predetermined locations on a surface of the web of media as it is advanced through the plating solution in the reservoir; and   a distribution system for injecting an inert gas into the plating solution, wherein the distribution system includes an injector for injecting the inert gas into the plating solution, wherein the injector includes:
 a converging tube segment; 
 a diverging tube segment downstream of the converging tube segment; 
 a throat formed at a junction of the converging tube segment and the diverging tube segment; and 
 an inlet for the inert gas in proximity to the throat. 
   
     
     
         2 . The roll-to-roll electroless plating system of  claim 1 , wherein diameters of the converging and diverging tube segments increase with distance from the throat. 
     
     
         3 . The roll-to-roll electroless plating system of  claim 1 , wherein the injector is located downstream of a pump which pumps the plating solution through the injector. 
     
     
         4 . The roll-to-roll electroless plating system of  claim 1 , wherein the injector injects micro-bubbles of the inert gas into the plating solution, wherein the micro-bubbles have a diameter between about one micron and one millimeter. 
     
     
         5 . The roll-to-roll electroless plating system of  claim 1 , wherein the plating substance is copper, silver, nickel or palladium. 
     
     
         6 . The roll-to-roll electroless plating system of  claim 1 , wherein the inert gas is nitrogen or argon. 
     
     
         7 . The roll-to-roll electroless plating system of  claim 1 , further including a recirculation system including:
 a recirculation pump including an inlet and an outlet;   an inlet line for moving plating solution from the reservoir to the pump inlet; and   an outlet line for returning plating solution from the pump outlet to the reservoir.   
     
     
         8 . The roll-to-roll electroless plating system of  claim 7 , wherein the distribution system is configured to inject the inert gas into the outlet line. 
     
     
         9 . The roll-to-roll electroless plating system of  claim 7 , further comprising a filter in the outlet line. 
     
     
         10 . The roll-to-roll electroless plating system of  claim 1 , wherein the distribution system includes a plumbing assembly having a plurality of distributed orifices for providing bubbles of inert gas into the reservoir. 
     
     
         11 . The roll-to-roll electroless plating system of  claim 10 , wherein the plumbing assembly is disposed proximate to a bottom of the sump. 
     
     
         12 . The roll-to-roll electroless plating system of  claim 1 , further comprising an oxygen sensor. 
     
     
         13 . The roll-to-roll electroless plating system of  claim 12 , further comprising a controller, wherein the controller is configured to receive data from the oxygen sensor and to control a rate of injection of the inert gas into the plating solution in response to the data received from the oxygen sensor. 
     
     
         14 . The roll-to-roll electroless plating system of  claim 13 , wherein a dissolved oxygen content of the plating solution is controlled to be between 0.5 and 2 parts per million. 
     
     
         15 . The roll-to-roll electroless plating system of  claim 1 , wherein the reservoir further includes a reservoir cover. 
     
     
         16 . The roll-to-roll electroless plating system of  claim 1 , wherein the distribution system further includes a static mixer. 
     
     
         17 . The roll-to-roll electroless plating system of  claim 1 , wherein the predetermined locations include features printed onto the web of media with ink including a catalyst for plating. 
     
     
         18 . An article having features that were plated using the roll-to-roll electroless plating system of  claim 1 . 
     
     
         19 . The article of  claim 18 , wherein at least some of the features have widths between 2 microns and 10 microns.