Electroless nickel plating solutions
AssigneeAtotech Deutschland GmbH
InventorGeorge E. Shahin
Life of this patent
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Abstract
This invention relates to aqueous electroless nickel plating solutions, and more particularly, to nickel plating solutions based on nickel salts of alkyl sulfonic acids as the source of nickel ions. The plating solutions utilize, as a reducing agent, hypophosphorous acid or bath soluble salts thereof selected from sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite. The electroless nickel plating solutions of the invention are free of added nickel hypophosphite, and free of alkali or alkaline earth metal ions capable of forming an insoluble orthophosphite.
Claims26
An aqueous electroless nickel plating solution comprising:
- (A) a nickel salt of an alkyl sulfonic acid, and
- (B) hypophosphorous acid or a bath soluble salt thereof selected from sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite,
- wherein the solution is free of added nickel hypophosphite, and free of alkali or alkaline earth metal ions capable of forming an insoluble orthophosphite.
An aqueous electroless nickel plating solution prepared from:
- (A) a nickel salt of an alkyl sulfonic acid, and
- (B) hypophosphorous acid or a bath soluble salt thereof selected from sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite,
- wherein the solution is free of added nickel hypophosphite, and free of alkali or alkaline earth metal ions capable of forming an insoluble orthophosphite.
A process for the electroless deposition of nickel on a substrate from a nickel plating solution which comprises contacting the substrate with a solution comprising:
- (A) a nickel salt of an alkyl sulfonic acid, and
- (B) hypophosphorous acid or a bath soluble salt thereof selected from sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite,
- wherein the solution is free of added nickel hypophosphite, and free of alkali or alkaline earth metal ions capable of forming an insoluble orthophosphite.
A process for the electroless deposition of nickel on a substrate with a nickel plating solution which comprises:
- (A) preparing a nickel plating solution comprising
- (i) a nickel salt of methane sulfonic acid or methane disulfonic acid,
- (ii) hypophosphorous acid or a bath soluble salt thereof selected from sodium hypophosphite, potassium hypophosphite and ammonium hypophosphite
- wherein the nickel plating solution is free of added nickel hypophosphite, and free alkali or alkaline earth metal ions capable of forming an insoluble orthophosphite, and
- (B) contacting the substrate with the plating solution prepared in (A).
Dependencies are inferred from the claim text.