Electrodeposition of bright tin-nickel alloy
AssigneeNASGLO International Corporation
InventorMartin H. Pollack
Life of this patent
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Abstract
An alloy of 0.001-0.30 weight percent nickel, the balance being essentially tin. The alloy provides a brightness, smoothness, solderability and electrical conductivity comparable to gold and is electrodeposited from an aqueous bath containing nickel sulfate, nickel fluoborate, nickel sulfamate, stannous sulfate or stannous fluoborate, benzene sulfonic acid, sulfuric acid, fluoboric acid or sulfamic acid providing a pH not higher than 1, and a brightener. The concentration of the tin salt in the bath is at least about 1 oz./gal. and the weight ratio of the nickel salt to the tin salt is at least 0.20 to 1. Substrates which may be coated with the alloy include iron, nickel, silver and copper, alloys of copper, and aluminum or zinc coated with nickel, silver or copper, or any combinations thereof.
Claims7
An aqueous electroplating bath capable of depositing an alloy consisting essentially of 0.001- 0.30 wt. % nickel and the balance tin, said bath consisting essentially of (a) a nickel salt selected from nickel sulfate, nickel fluoborate and nickel sulfamate, (b) a corresponding tin salt, (c) sulfuric acid, sulfamic acid, benzene sulfonic acid or fluoboric acid in an amount providing a pH of not higher than 1, and (d) an effective amount of a brightening agent, wherein the concentration of said tin salt is at least about 1 oz./gal. and the weight ratio of said nickel salt to said tin salt is at least 0.20 to 1.
Dependencies are inferred from the claim text.