Patent ID: 6500482
Filing Date: 2002-12-31
Classification: C23C

Abstract:
A process for electrolessly plating nickel, which process comprises contacting a substrate with a plating composition contained within a plating tank, which plating composition comprises:(a) a soluble source of nickel ions; (b) complexing agents; (c) a hypophosphite reducing agent; and (d) a pH adjusting agent selected from the group consisting of alkali metal hydroxides, alkaline earth hydroxides, and mixtures of the foregoing; wherein a portion of the plating composition is regularly or continually removed from the plating tank, cooled to below about 140Â° F., and then the pH of the removed and cooled portion of the plating solution is monitored and adjusted by adding the pH adjusting agent with mixing, and thereafter returning the removed and cooled portion of the plating composition to the plating tank wherein the pH adjusting agent is a solution of an alkali metal hydroxide comprising less than about 700 g/l of alkali metal hydroxide.