Method for providing a conductive surface on a non-conductive polymeric surface

Abstract

The invention relates to a method for providing a conductive surface on a non-conductive surface, in particular a polymeric surface. In particular the method relates to attaching silver ions to a polymeric surface to facilitate the adhesion of a metallic layer to the polymeric surface.

1 . A method for providing a conductive surface on a nonconductive substrate comprising the steps of:
 a. providing a nonconductive substrate;   b. conditioning the nonconductive substrate with a hydrophilizing agent to render the substrate hydrophilic;   c. contacting the nonconductive substrate with an aqueous solution comprising a metal ion;   d. covalently bonding the metal ion to the conditioned nonconducting substrate by the application of energy to form an activated substrate surface comprising metal seeds; and   e. contacting the activated substrate surface with an electroless plating solution comprising a plating metal salt and a reducing agent, the reducing agent being suitable for reducing both the plating metal salt and the metal ion seeds on the activated substrate surface to thereby form a conductive surface on the nonconductive substrate.   
     
     
         2 . The method of  claim 1  wherein the nonconductive substrate is a polymeric substrate. 
     
     
         3 . The method according to  claim 1 , wherein the conditioned chemical bonds on the surface of the nonconducting substrate includes a percentage/proportion of carbon-carbon double bonds of between about 10 to about 50% of the carbon backbone of the substrate. 
     
     
         4 . The method according to  claim 1 , wherein the hydrophilizing agent is a solution comprising one permanganate salt, one acid and one complexing agent sourced from phosphorus containing species, having a phosphorus containing anion group of between about 0.01 and about 1 mol/L. 
     
     
         5 . The method according to  claim 1  wherein the conditioning step with the hydrophilization agent is performed between about 5 and about 20 minutes. 
     
     
         6 . The method according to  claim 1  where the conditioning step with the hydrophilization agent is performed between about 25 and about 45 degrees Celsius. 
     
     
         7 . The method according to  claim 1 , wherein the aqueous solution comprising a metal ion further includes a complexing agent, and optionally a surfactant. 
     
     
         8 . The method according to  claim 7  wherein,
 i. the complexing agent may be an ammonium ion; 
 ii the surfactant when present is polyvinylpyrrolidone (PVP). 
 
     
     
         9 . (canceled) 
     
     
         10 . The method according to  claim 7  wherein the aqueous solution comprising a metal ion is maintained at a temperature of between about 10 and about 40 degrees Celsius. 
     
     
         11 . The method according to  claim 1 , wherein the non-conducting substrate is contacted with the aqueous solution comprising a metal ion. 
     
     
         12 . The method according to  claim 11 , having a contact time between the nonconductive substrate and the aqueous solution of between about 1 and about 10 minutes. 
     
     
         13 . (canceled) 
     
     
         14 . The method according to  claim 1 , wherein the aqueous solution comprising a metal ion comprises one or more of AgNO 3 , CuSO 4 , NiSO 4 , or CuCl 2  in a concentration between about 0.005 and about 0.1 mol/L. 
     
     
         15 . The method according to  claim 1 , wherein the energy source is heat and the temperature is between about 60 and about 90 degrees Celsius. 
     
     
         16 . The method according to  claim 15 , wherein the energy source is applied as a hot air stream or a hot air environment. 
     
     
         17 . The method according to  claim 1 , wherein the energy is applied for a contact time of between about 2 and about 10 minutes. 
     
     
         18 . The method according to  claim 1 , wherein
 i. the metal is Ag, and the electroless plating solution comprises electroless nickel boron, and the reducing agent amine borane; or   ii the metal is Ag, and the electroless plating solution comprises copper, and the reducing agent is selected from formaldehyde and amine borane.   
     
     
         19 . (canceled) 
     
     
         20 . A conductive metal surface comprising a hydrophilic conditioned nonconductive substrate, activated metal seeds, an electroless metal deposited metal surface, and an electroplated metal surface. 
     
     
         21 . The conductive metal surface according to  claim 20 , having a density of activated metal seeds is sufficient to produce a bonding strength of 10 N/cm or higher when tested according to ASTM B533. 
     
     
         22 . A conductive metal surface comprising a hydrophilic conditioned nonconductive substrate, activated metal seeds, an electroless metal deposited metal surface, and an electroplated metal surface, produced according to the process of  claim 1 .