Plating bath for the electroless plating of a substrate

Abstract

A plating bath for electroless plating of a substrate with nickel. The plating bath includes a nickel ion source and a stabilizing system comprising an iodate ion source and a heavy metal ion source. The substrate can be a copper or aluminum substrate.

1 . A plating bath for electroless plating of a substrate with nickel, the plating bath comprising a nickel ion source and a stabilizing system comprising an iodate ion source and a heavy metal ion source. 
     
     
         2 . The plating bath according to  claim 1 , wherein the heavy metal ion source is a copper salt. 
     
     
         3 . The plating bath according to  claim 1 , wherein the iodate ion source is potassium iodate. 
     
     
         4 . The plating bath according to  claim 1 , further comprising at least one reducing agent. 
     
     
         5 . The plating bath according to  claim 1 , wherein the nickel ion source is nickel sulfate. 
     
     
         6 . The plating bath according to  claim 1 , wherein the iodate ion source has a concentration of approximately 100 μl of a 0.05 molar solution/l to approximately 400 μl of a 0.05 molar solution/l and the heavy metal ion source has a concentration of approximately 20 μl of a 0.1 molar solution/l to approximately 80 μl of a 0.1 molar solution/l. 
     
     
         7 . The plating bath according to  claim 1 , wherein the plating bath has a pH of approximately 3 to 5 and a temperature of approximately 80° C. to 90° C. 
     
     
         8 . A use of an iodate ion source and a heavy metal ion source, in particular a copper ion source, for stabilizing a nickel plating bath. 
     
     
         9 . A method for depositing nickel on a substrate, the method comprising the following steps:
 a) treating the substrate to be plated with an acid;   b) activating the substrate surface using palladium;   c) contacting the activated substrate with a plating bath according to  claim 1 .   
     
     
         10 . The plating bath of  claim 1 , wherein the substrate is a copper or aluminum substrate. 
     
     
         11 . The plating bath according to  claim 1 , wherein the heavy metal ion source is a copper sulfate. 
     
     
         12 . The plating bath according to  claim 4 , wherein the reducing agent comprises sodium hypophosphite and/or DMAB (dimethylaminoborane). 
     
     
         13 . The plating bath according to  claim 4 , wherein the reducing agent comprises at least one complexing agent and at least one pH adjuster. 
     
     
         14 . The plating bath according to  claim 6 , wherein the iodate ion source is potassium iodate. 
     
     
         15 . The plating bath according to  claim 6 , wherein the heavy metal ion source is CuSO 4 .5H 2 O. 
     
     
         16 . The plating bath according to  claim 6 , wherein the iodate ion source-has a concentration of approximately 200 μl of a 0.05 molar solution/l, and the heavy metal ion source has a concentration of approximately 40 μl of a 0.1 molar solution/l. 
     
     
         17 . The plating bath according to  claim 1 , wherein the plating bath has a pH of approximately 4.4, and a temperature of approximately. 
     
     
         18 . The method of  claim 9 , wherein the step of treating the substrate to be plated comprises treating the substrate with sulfuric acid.