Chromium-free antitarnish adhesion promoting treatment composition

Abstract

The present invention is directed to an aqueous, antitarnish and adhesion promoting treatment composition, comprising: zinc ions; metal ions selected from the group consisting of tungsten ions, molybdenum ions, cobalt ions, nickel ions, zirconium ions, titanium ions, manganese ions, vanadium ions, iron ions, tin ions, indium ions, silver ions, and combinations thereof; and optionally, an electrolyte that does not contain potassium or sodium ions; wherein the treatment composition is substantially free of chromium, and wherein the treatment composition forms a coating on a substrate or material that enhances adhesion of a polymer to the material. The present invention is also directed to materials coated with the above treatment composition, and methods of coating materials using the above composition.

1 . An aqueous, antitarnish and adhesion promoting treatment composition, comprising: 
 zinc ions;    metal ions selected from the group consisting of tungsten ions, molybdenum ions, cobalt ions, nickel ions, zirconium ions, titanium ions, manganese ions, vanadium ions, iron ions, tin ions, indium ions, silver ions, and combinations thereof; and    optionally, an electrolyte that does not contain potassium or sodium ions;    wherein said treatment composition is substantially free of chromium, and wherein said treatment composition is capable of forming a coating on a material, wherein said coating enhances adhesion of a polymer to said material.    
     
     
         2 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said zinc ions are derived from a zinc salt.  
     
     
         3 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 2 , wherein said zinc salt is selected from the group consisting of zinc sulfate, zinc oxide, zinc chloride, zinc fluoborate, zinc acetate, hydrates thereof, and combinations thereof.  
     
     
         4 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said zinc ions comprise from about 0.1 g/L to about 100 g/L.  
     
     
         5 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said zinc ions comprise from about 0.5 g/L to about 50 g/L.  
     
     
         6 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said zinc ions comprise from about 0.5 g/L to about 20 g/L.  
     
     
         7 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said metal ions are derived from a corresponding metal salt or metal acid.  
     
     
         8 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 7 , wherein said metal salt is selected from the group consisting of nickel sulfate, ammonium molybdate, molybdenum oxide, potassium permanganate, manganese sulfate, hydrates thereof, and combinations thereof.  
     
     
         9 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 7 , wherein said metal acid is selected from the group consisting of molybdic acid, tungstic acid, tungstosilicic acid.  
     
     
         10 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said metal ions are selected from the group consisting of molybdenum and tungsten.  
     
     
         11 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said metal ions comprise from about 5 to about 20,000 ppm, based on the total parts of said treatment composition.  
     
     
         12 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said metal ions comprise from about 15 to about 2,000 ppm, based on the total parts of said treatment composition.  
     
     
         13 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said metal ions comprise from about 25 to about 300 ppm, based on the total parts of said treatment composition.  
     
     
         14 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said optional electrolyte is selected from the group consisting of ammonium sulfate, boric acid, citric acid, gluconic acid, rubidium hydroxide, ammonium chloride, and combinations thereof.  
     
     
         15 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said electrolyte comprises from about 1 g/L to about 500 g/L.  
     
     
         16 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said electrolyte comprises from about 5 g/L to about 200 g/L.  
     
     
         17 . The aqueous, antitarnish and adhesion promoting treatment composition of  claim 1 , wherein said electrolyte comprises from about 10 g/L to about 50 g/L.  
     
     
         18 . A material coated with an antitarnish and adhesion treatment coating, comprising 
 zinc or zinc oxide atoms; and    metal or metal oxide atoms selected from the group consisting of tungsten, molybdenum, cobalt, nickel, zirconium, titanium, manganese, vanadium, iron, tin, indium, silver, and combinations thereof;    wherein said coating is substantially free of chromium, and wherein said coating provides a tarnish resistance at least for 30 min at 250° C., and wherein said coating contains nodular structures that enhance adhesion of a polymer to said material.    
     
     
         19 . The coated material of  claim 18 , wherein said material comprises a material selected from the group consisting of copper, copper alloy, nickel, iron, aluminum, steel, stainless steel, zinc, tin, silver, palladium, gold, titanium, carbon, metallized non-conductors, and combinations thereof.  
     
     
         20 . The coated material of  claim 18 , wherein the thickness of said coating on said substrate ranges from about 15 to about 500 Angstroms.  
     
     
         21 . The coated material of  claim 18 , wherein said coating contains from about 25 to about 1000 of said nodular structures per 16 square microns.  
     
     
         22 . The coated material of  claim 18 , wherein said nodular structures each have an average length in the range of from about 0.01 micron to about 1 micron, and an aspect ratio (length to diameter) of from about 1:1 to about 8:1.  
     
     
         23 . The coated material of  claim 18 , comprising a coated substrate.  
     
     
         24 . The substrate of  claim 23 , comprising an electronic device.  
     
     
         25 . The substrate of  claim 23 , comprising a device/leadframe assembly.  
     
     
         26 . The coated material of  claim 18 , wherein said enhanced adhesion comprises greater than 1000 psi following exposure of said coated substrate to 85% RH/80-85° C. for 168 hr, followed by a thermal shock in approximately 260° C. solder for 120 sec.  
     
     
         27 . A method of forming a material coated with an antitarnish and adhesion promoting coating, comprising the steps of: 
 contacting said material with an aqueous, antitarnish and adhesion promoting treatment composition, comprising: 
 zinc ions;  
 metal ions selected from the group consisting of tungsten ions, molybdenum ions, cobalt ions, nickel ions, zirconium ions, titanium ions, manganese ions, vanadium ions, iron ions, tin ions, indium ions, silver ions, and combinations thereof; and  
 optionally, an electrolyte that does not contain potassium or sodium ions;  
 wherein said treatment composition is substantially free of chromium; and  
   passing an electric current through said treatment composition under conditions which deposit said antitarnish and adhesion promoting coating on said material to form said material coated with said antitarnish and adhesion promoting coating, wherein said coating enhances adhesion of a polymer to said material.    
     
     
         28 . The method of  claim 27 , wherein said material comprises a material selected from the group consisting of copper, copper alloy, nickel, iron, aluminum, steel, stainless steel, zinc, tin, silver, palladium, gold, titanium, carbon, metallized non-conductors, and combinations thereof.  
     
     
         29 . The method of  claim 27 , wherein said conditions comprise temperatures in the range of from about 100 to about 150° F.  
     
     
         30 . The method of  claim 27 , wherein said electric current ranges from about 2 to about 200 asf.  
     
     
         31 . The method of  claim 27 , wherein said conditions comprise deposition times ranging from about 1 to about 200 seconds.  
     
     
         32 . The method of  claim 27 , wherein said zinc ions are derived from a zinc salt selected from the group consisting of zinc sulfate, zinc oxide, zinc chloride, zinc fluoborate, zinc acetate, hydrates thereof, and combinations thereof.  
     
     
         33 . The method of  claim 27 , wherein said zinc ions comprise from about 0.1 g/L to about 100 g/L.  
     
     
         34 . The method of  claim 27 , wherein said metal ions are derived from a corresponding metal salt selected from the group consisting of nickel sulfate, ammonium molybdate, molybdenum oxide, potassium permanganate, hydrates thereof, and combinations thereof; or a metal acid selected from the group consisting of molybdic acid, tungstic acid, tungstosilicic acid, and combinations thereof.  
     
     
         35 . The method of  claim 27 , wherein said metal ions comprise from about 5 to about 20,000 ppm, based on the total parts of said treatment composition.  
     
     
         36 . The method of  claim 27 , wherein said electrolyte is selected from the group consisting of ammonium sulfate, boric acid, citric acid, gluconic acid, rubidium hydroxide, ammonium chloride, and combinations thereof.  
     
     
         37 . The method of  claim 36 , wherein said electrolyte comprises from about 1 g/L to about 500 g/L.  
     
     
         38 . The method of  claim 27 , wherein said coating on said substrate has a thickness ranging from about 15 to about 500 Angstroms.  
     
     
         39 . The method of  claim 27 , wherein coated substrate contains from about 25 to about 1000 of said nodular structures per 16 square microns.  
     
     
         40 . The method of  claim 27 , wherein said nodular structures each have an average length in the range of from about 0.01 micron to about 1 micron, and an aspect ratio (length to diameter) of from about 1:1 to about 8:1.  
     
     
         41 . The method of  claim 27 , wherein said material comprises a substrate.  
     
     
         42 . The method of  claim 41 , wherein said substrate comprises an electronic device.  
     
     
         43 . The method of  claim 41 , wherein said substrate comprises a device/leadframe assembly.