Very ultra thin conductor layers for printed wiring boards

Abstract

Disclosed is a metal-clad laminate product having a carrier film, a aqueous soluble release or parting layer deposited onto the carrier film and which can be mechanically separated from the carrier film, and an ultra thin metal layer deposited onto the parting layer. Also disclosed is a method for making the metal-clad laminate product.

It is claimed:  
     
         1 . A metal-clad laminate product for the manufacture of printed circuit boards, the product comprising: 
 (a) a carrier film;    (b) a release agent layer covering a surface of the carrier film, the release agent layer comprising an aqueous soluble polymer, the release agent layer being capable of being mechanically peeled from the carrier layer; and    (c) a conductive metal layer deposited onto the release agent layer, the metal layer having a thickness of at most 10,000 Angstroms.    
     
     
         2 . The laminate product of  claim 1  wherein the release agent layer comprises polyvinyl pyrrolidone.  
     
     
         3 . The laminate product of  claim 2  wherein the polyvinyl pyrrolidone in the release layer has a molecular weight of between 10,000 and 5,000,000.  
     
     
         4 . The laminate product of  claim 1  wherein the carrier layer is a polymeric film.  
     
     
         5 . The laminate product of  claim 1  wherein the carrier layer is a metal foil.  
     
     
         6 . The laminate product of  claim 1  further comprising an adhesive layer on the metal layer on its side opposite from the release agent layer.  
     
     
         7 . The laminate product of  claim 1 , further comprising at least one semi-cured resin laminate layer adhered to the conductive metal layer.  
     
     
         8 . A metal-clad laminate intermediate product for use in the manufacture of printed circuit boards, the product comprising: 
 (a) a carrier film;    (b) a release agent lay covering one surface of the carrier film, the release agent layer comprising an organic polymer which facilitates the release layer being mechanically peeled from the carrier film;    (c) a primary conductive metal layer deposited onto the release layer, the metal conductive layer being no thicker that about 10,000 Angstroms; and    (d) a secondary metal layer deposited on the primary metal layer, the secondary layer having a thickness of at most 300 Angstroms.    
     
     
         9 . The laminate product of  claim 8  wherein the release agent layer comprises polyvinyl pyrrolidone.  
     
     
         10 . The laminate product of  claim 9  wherein the polyvinyl pyrrolidone in the release layer has a molecular weight of between 10,000 and 5,000,000.  
     
     
         11 . The laminate product of  claim 8  wherein the carrier layer is a polymeric film.  
     
     
         12 . The laminate product of  claim 8  wherein the carrier layer is a metal foil.  
     
     
         13 . The laminate product of  claim 8  further comprising an adhesive layer on the metal layers on the side opposite from the release agent layer.  
     
     
         14 . The laminate product of  claim 8  further comprising at least one semi-cured resin layer adhered to the conductive layer.  
     
     
         15 . A method for making a metal-clad laminate product comprising the steps of: 
 (a) providing a carrier film of dimensionally stable material;    (b) depositing onto the carrier layer a release agent layer, the release agent layer comprising an aqueous soluble polymer, the release agent layer being capable of being mechanically peeled from the carrier layer;    (c) forming a conductive metal layer on the release agent layer, the metal layer comprising a metal selected from the group consisting of copper, gold, chrome, tin, nickel, aluminum, titanium, zinc, and mixtures thereof, the metal layer having a thickness of at most about 10,000 Angstroms;    (d) bonding the metal layer to a resin circuit board laminate layer; and    (e) peeling the carrier film from the metal layer without damaging the metal layer attached to the circuit board laminate layer.    
     
     
         16 . A method as claimed in  claim 15  wherein the release agent layer is formed of polyvinyl pyrrolidone.  
     
     
         17 . A method for making a metal-clad laminate product comprising the steps of: 
 (a) providing a carrier film of dimensionally stable suitable material;    (b) depositing onto the carrier film a release agent layer, the release agent layer comprising an aqueous soluble polymer, the release agent layer being capable of being mechanically peeled from the carrier layer;    (c) forming a conductive metal layer on the release agent layer, the metal layer comprising a metal selected from the group consisting of copper, gold, chrome, tin, nickel, aluminum, titanium, zinc, and mixtures thereof, the metal layer having a thickness of at most about one μm;    (d) applying a first one resin circuit board laminate layer to the metal layer and semi-curing the resin;    (e) applying a second resin circuit board laminate layer to the first resin circuit board laminate layer and semi-curing the second layer while additionally curing the first layer; and    (f) removing the carrier film without damaging the conductive metal layer.    
     
     
         18 . A method as claimed in  claim 17  wherein the release agent layer is polyvinyl pyrrolidone.