Method of electrolytically dissolving nickel into electroless nickel plating solutions

US8177956B2 · kind B2 · utility

Inventors

• Nicole J. Micyus · South Lyon, US
• Carl Steinecker · South Lyon, US
• Duncan P. Beckett · Tamworth, GB

Key dates

• Filing date: Mar 12, 2008
• Grant date: May 15, 2012
• Expiry date: Mar 16, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C18/36
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method of extending the lifetime of an electroless nickel plating bath by avoiding the addition of unwanted anions to the process and of improving the pH stability of the bath and minimizing additions of pH correcting additives. The method includes the steps of (a) depositing electroless nickel from an electroless nickel plating bath onto a substrate, wherein the electroless nickel plating bath preferably contains a source of nickel ions and a source of hypophosphite ions; (2) immersing a nickel anode in the plating bath; (3) completing the circuit by utilizing a cathode separated from the nickel bath by an ion exchange membrane and using a catholyte comprising an acid or a salt thereof; and (4) passing a current through the bath. Nickel is dissolved into the plating bath to maintain the nickel concentration and hydrogen is discharged from the cathode.