Pyrophosphate-containing bath for cyanide-free deposition of copper-tin alloys

Abstract

A pyrophosphate-containing bath for the cyanide-free deposition of copper alloys on substrate surfaces, comprising a reaction product of a secondary monoamine with a diglycidyl ether, is described. The electrolyte bath is suitable for the galvanic deposition of glossy white, even and uniform copper-tin alloy coatings.

1 - 25 . (canceled) 
     
     
         26 . A pyrophosphate-containing bath for the cyanide-free deposition of copper-tin alloys on substrate surfaces, comprising a reaction product of a secondary monoamine with a diglycidyl ether, wherein the secondary monoamine is morpholine and the diglycidyl ether is selected from the group consisting of glycerol diglycidyl ether, poly(propylene glycol) diglycidyl ether, poly(ethylene glycol) diglycidyl ether and mixtures thereof. 
     
     
         27 . The pyrophosphate-containing bath according to  claim 26 , wherein the diglycidyl ether is glycerol diglycidyl ether. 
     
     
         28 . The pyrophosphate-containing bath according to  claim 26 , wherein the molar ratio of diglycidyl ether to secondary monoamine is 0.8 to 2. 
     
     
         29 . The pyrophosphate-containing bath according to  claim 28 , wherein the molar ratio is 0.9 to 1.5. 
     
     
         30 . The pyrophosphate-containing bath according to  claim 26 , wherein the reaction product is contained in a concentration of 0.0001 to 20 g/l. 
     
     
         31 . The pyrophosphate-containing bath according to  claim 30 , wherein the reaction product is contained in a concentration of 0.001 to 1 g/l. 
     
     
         32 . The pyrophosphate-containing bath according to  claim 26 , further comprising an additive selected from the group consisting of orthophosphoric acid, an organic sulfonic acid, boric acid, an antioxidant agent and an organic brightener. 
     
     
         33 . The pyrophosphate-containing bath according to  claim 26 , further comprising N-methylpyrrolidone. 
     
     
         34 . The pyrophosphate-containing bath according to  claim 33 , wherein the N-methylpyrrolidone is contained in a concentration of 0.1 to 50 g/l. 
     
     
         35 . The pyrophosphate-containing bath according to  claim 34 , wherein N-methylpyrrolidone is contained in a concentration of 0.5 to 15 g/l. 
     
     
         36 . The pyrophosphate-containing bath according to  claim 26  with a pH value of 3 to 9. 
     
     
         37 . The pyrophosphate-containing bath according the  claim 36  with a pH value of 6 to 8. 
     
     
         38 . A method for the galvanic deposition of glossy and even copper-tin alloy coatings, comprising the introducing of a substrate to be coated into an aqueous cyanide-free electrolyte bath according to  claim 26  and depositing the copper-tin alloy coating on the substrate. 
     
     
         39 . The method according to  claim 38 , wherein the bath is operated at a set current density of 0.01 to 2 A/dm 2 . 
     
     
         40 . The method according to  claim 39 , wherein the bath is operated at a set current density of 0.25 to 0.75 A/dm 2 . 
     
     
         41 . The method according to  claim 38 , wherein the bath is operated at a temperature of 15 to 50° C. 
     
     
         42 . The method according to  claim 38 , wherein the bath is operated at a temperature of 20 to 30° C. 
     
     
         43 . The method according to  claim 38 , wherein the coatings are deposited on a conductive substrate by means of a rack plating method. 
     
     
         44 . The method according to  claim 38 , wherein membrane anodes are used as anodes. 
     
     
         45 . The reaction product of a secondary monoamine with a diglycidyl ether, wherein the secondary monoamine is morpholine and the diglycidyl ether is selected from the group consisting of glycerol diglycidyl ether, poly(propylene glycol) diglycidyl ether, poly(ethylene glycol) diglycidyl ether and mixtures thereof. 
     
     
         46 . The reaction product according to  claim 45 , wherein the diglycidyl ether is glycerol diglycidyl ether. 
     
     
         47 . The reaction product according to  claim 45 , wherein the molar ratio of diglycidyl ether to secondary monoamine is 0.8 to 2. 
     
     
         48 . The reaction product according to  claim 45 , wherein the molar ratio is 0.9 to 1.5. 
     
     
         49 . The use of a reaction product according to  claim 45  as brightener.