Nickel electroplating compositions with copolymers of arginine and bisepoxides and methods of electroplating nickel
Nickel electroplating compositions containing copolymers of arginine and a bisepoxide enable the electroplating of nickel deposits which have uniform bright surfaces over wide current density ranges.
1. A nickel electroplating composition comprising one or more sources of nickel ions, one or more compounds chosen from sodium saccharinate, boric acid and salts of boric acid, optionally, one or more sources of acetate ions, and one or more copolymers of arginine and one or more bisepoxides, wherein the one or more one or more bisepoxides have a formula:
wherein Y 1 and Y 2 are independently chosen from H and linear or branched (C 1 -C 4 )alkyl;
A is OR 1 or R 2 , wherein R 1 is ((CR 3 R 4 ) m )O) n , wherein R 3 and R 4 are independently chosen from H, hydroxyl and methyl, and R 2 is (CH 2 ) y , wherein m is a number from 1 to 6, n is a number from 1 to 20 and y is a number from 0 to 6 and when y is 0, A is a covalent chemical bond.
2. The nickel electroplating composition of claim 1 , wherein the one or more copolymers of arginine and one or more bisepoxides are in amounts of at least 0.1 ppm.
3. The nickel electroplating composition of claim 1 , wherein the one or more sources of acetate ions are chosen from nickel acetate, nickel acetate tetrahydrate, alkali metal salts of acetate and acetic acid.
4. The nickel electroplating composition of claim 1 , further comprising one or more sources of chloride.
5. The nickel electroplating composition of claim 1 , wherein a pH of the nickel electroplating composition is from 2 to 6.
6. A method of electroplating nickel metal on a substrate comprising:
a) providing the substrate;
b) contacting the substrate with a nickel electroplating composition comprising one or more sources of nickel ions, one or more compounds chosen from sodium saccharinate, boric acid and salts of boric acid, optionally, one or more sources of acetate ions, and one or more copolymers of arginine and one or more bisepoxides, wherein the one or more bisepoxides have a formula:
wherein Y 1 and Y 2 are independently chosen from H and linear or branched (C 1 -C 4 )alkyl; A is OR 1 or R 2 , wherein R 1 is ((CR 3 R 4 ) m )O) n , wherein R 3 and R 4 are independently chosen from H, hydroxyl and methyl, and R 2 is (CH 2 ) y , wherein m is a number from 1 to 6, n is a number from 1 to 20 and y is a number from 0 to 6 and when y is 0, A is a covalent chemical bond; and
c) applying an electric current to the nickel electroplating composition and substrate to electroplate a bright and uniform nickel deposit adjacent the substrate.
7. The method of claim 6 , wherein the one or more sources of acetate ions of the nickel electroplating composition are chosen from nickel acetate, nickel acetate tetrahydrate, alkali metal salts of acetate and acetic acid.
8. The method of claim 6 , wherein the nickel electroplating composition further comprises one or more sources of chloride.
9. The method of claim 6 , wherein the nickel electroplating composition has a pH of 2 to 6.