Method for Manufacturing an Emi Shielding Element

Abstract

A method for manufacturing an EMI shielding element from a sheet of polymer material includes forming the shielding element by vacuum- or pressure-molding. The formed element is then chemically etched to roughen its surface on a microscopic scale. The surface is subsequently treated with a catalyzing solution to enable the shielding element to be plated by electroless plating. A first metallic layer is deposited on the etched and catalyzed surface by electroless plating, and a second metallic layer is deposited on the first by electrolytic plating.

1 . A method for manufacturing a shielding element for use in providing EMI shielding for electronic equipment, said method comprising the steps of:
 a) providing a sheet of a polymer material;   b) forming a part having a three-dimensional geometry desired for said shielding element from said sheet of polymer material;   c) etching said part to roughen the surface thereof on a microscopic level;   d) catalyzing said surface of said part with a catalyzing solution to enable said surface to be plated by electroless plating;   e) performing electroless plating on said part to deposit a first metallic layer on the surface thereof; and   f) performing electrolytic plating on said part to deposit a second metallic layer on said first metallic layer.   
     
     
         2 . A method as claimed in  claim 1  wherein said polymer material is selected from the group consisting of polytetrafluoroethylene, polyester and polypropylene. 
     
     
         3 . A method as claimed in  claim 1  wherein said polymer material is ABS (acrylonitrile-butadiene-styrene copolymer). 
     
     
         4 . A method as claimed in  claim 1  wherein said polymer material is HIPS (high-impact polystyrene). 
     
     
         5 . A method as claimed in  claim 1  wherein said polymer material is PC-ABS (polycarbonate-acrylonitride-butadiene-styrene copolymer). 
     
     
         6 . A method as claimed in  claim 1  wherein said part is formed from said sheet by pressure-molding. 
     
     
         7 . A method as claimed in  claim 1  wherein said part is formed from said sheet by vacuum-molding. 
     
     
         8 . A method as claimed in  claim 1  further comprising, between steps b) and c), the step of cleaning said part formed from said sheet of polymer material. 
     
     
         9 . A method as claimed in  claim 8  wherein said cleaning step includes dipping said part in a solvent. 
     
     
         10 . A method as claimed in  claim 9  wherein said solvent is 1-propanol. 
     
     
         11 . A method as claimed in  claim 1  wherein said etching step includes immersing said part in a chrome/sulfuric acid etching solution. 
     
     
         12 . A method as claimed in  claim 11  wherein said part is rinsed under running deionized water following immersion in said etching solution. 
     
     
         13 . A method as claimed in  claim 1  wherein said catalyzing solution has a tin and palladium mixture as a catalyzer. 
     
     
         14 . A method as claimed in  claim 1  wherein said catalyzing solution has a metal selected from the group consisting of palladium, gold, silver and platinum as a catalyzer. 
     
     
         15 . A method as claimed in  claim 1  wherein said electroless plating includes immersing said part in an electroless plating solution. 
     
     
         16 . A method as claimed in  claim 13  wherein said electroless plating solution has a metal selected from the group consisting of copper, nickel, cobalt, silver, gold and tin as the metal being plated to deposit said first metallic layer. 
     
     
         17 . A method as claimed in  claim 1  wherein a nickel anode in a sulfamate nickel solution is used in said electrolytic plating step to deposit nickel as said second metallic layer. 
     
     
         18 . A method as claimed in  claim 1  wherein a metal selected from the group consisting of nickel, tin, copper, zinc and chromium is deposited by electrolytic plating as said second metallic layer.