Metalization of flexible polymer sheets

Abstract

A conductive grid formation system, apparatus, and related methods may include a drum having a conductive surface, an insulation layer coating said surface, and a grid pattern formed in the insulation layer to expose portions of the conductive surface. The drum surface may be rotated into and out of a chemical bath, such that a metallic grid is electrodeposited in the exposed portions of the conductive surface. A polymer sheet may be laminated to the surface of the drum and then removed, such that the metallic grid attaches to the polymer sheet and is removed with the polymer sheet. Heat, pressure, and/or adhesive may be utilized in various steps of the process, to facilitate preferential adhesion of the metallic grid to the polymer sheet.

What is claimed is: 
     
         1 . A method of manufacturing a flexible electrical circuit, comprising:
 applying an electrically insulating coating to a cylinder, wherein the coating is patterned to expose portions of the surface of the cylinder in a pattern corresponding to an electrical circuit to be formed;   immersing the cylinder at least partially into a metal-containing solution;   electrodepositing metal from the metal-containing solution onto the exposed portions of the surface of the cylinder;   rotating the cylinder until the electrodeposited metal comes into contact with a flexible substrate contacting a portion of the cylinder; and   separating the flexible substrate from the cylinder with the electrodeposited metal attached to the substrate in the pattern corresponding to the flexible electrical circuit.   
     
     
         2 . The method of  claim 1 , wherein the flexible circuit is a radio frequency identification tag (RFID tag). 
     
     
         3 . The method of  claim 1 , wherein the flexible substrate is a flexible polymer sheet. 
     
     
         4 . The method of  claim 1 , further comprising patterning the electrically insulating coating with a laser, after applying the electrically insulating coating to the cylinder. 
     
     
         5 . The method of  claim 1 , wherein the electrically insulating coating is formed from a synthetic fluoropolymer. 
     
     
         6 . The method of  claim 1 , further comprising applying a release layer to the exposed portions of the surface of the cylinder. 
     
     
         7 . The method of  claim 1 , further comprising compressing the flexible substrate against the cylinder to increase adhesion between the flexible substrate and the electrodeposited metal, before separating the flexible substrate from the cylinder. 
     
     
         8 . A method of manufacturing a flexible electrical circuit, comprising:
 immersing a cylinder at least partially into a metal-containing solution, wherein the cylinder is electrically conductive and includes an electrically insulating coating adhered to the outer surface, and wherein the coating is patterned to expose portions of the outer surface in a pattern corresponding to an electrical circuit to be formed;   electrodepositing metal from the metal-containing solution onto the exposed portions of the outer surface of the cylinder;   rotating the cylinder until the electrodeposited metal comes into contact with a flexible substrate wrapped around a portion of the cylinder; and   separating the flexible substrate from the cylinder with the electrodeposited metal attached to the flexible substrate in the pattern corresponding to the electrical circuit.   
     
     
         9 . The method of  claim 8 , wherein the electrical circuit to be formed is a flexible circuit. 
     
     
         10 . The method of  claim 9 , wherein the pattern corresponds to a radio frequency identification tag (RFID tag). 
     
     
         11 . The method of  claim 8 , wherein the flexible substrate is a flexible polymer sheet. 
     
     
         12 . The method of  claim 8 , wherein the electrically insulating coating is formed from a synthetic fluoropolymer. 
     
     
         13 . The method of  claim 12 , wherein the synthetic fluoropolymer coating is formed from a material chosen from the set consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP) and a parylene polymer. 
     
     
         14 . The method of  claim 8 , further comprising applying a release layer to the exposed portions of the surface of the cylinder, prior to immersing the cylinder at least partially into the metal-containing solution. 
     
     
         15 . A method of manufacturing a flexible electrical circuit, comprising:
 providing an electrically conductive cylinder having an electrically insulating coating applied over the outer surface, wherein the coating is patterned to expose portions of the outer surface in a pattern corresponding to a flexible electrical circuit to be formed;   immersing the cylinder at least partially into a metal-containing solution;   electrodepositing metal from the metal-containing solution onto the exposed portions of the outer surface of the cylinder;   rotating the cylinder until the electrodeposited metal comes into contact with a flexible substrate; and   separating the flexible substrate from the cylinder with the electrodeposited metal attached to the substrate in the pattern corresponding to the flexible electrical circuit.   
     
     
         16 . The method of  claim 15 , further comprising patterning the electrically insulating coating with a laser to expose portions of the outer surface in the pattern corresponding to the flexible electrical circuit to be formed, prior to immersing the cylinder at least partially into the metal-containing solution. 
     
     
         17 . The method of  claim 15 , further comprising compressing the flexible substrate against the cylinder to increase adhesion between the flexible substrate and the electrodeposited metal, before separating the flexible substrate from the cylinder. 
     
     
         18 . The method of  claim 15 , wherein the flexible substrate is a flexible polymer sheet including a heat activated adhesive disposed on one side, and further comprising heating the flexible polymer sheet to activate the adhesive and increase adhesion between the flexible polymer sheet and the electrodeposited metal, before separating the flexible polymer sheet from the cylinder. 
     
     
         19 . The method of  claim 18 , further comprising cooling the flexible polymer sheet to reduce adhesion of the flexible polymer sheet to the cylinder, before separating the flexible polymer sheet from the cylinder. 
     
     
         20 . The method of  claim 15 , wherein the pattern corresponds to a radio frequency identification tag (RFID tag).