Macdermid, Incorporated

Leo J Slominski

Harold Leever

Thomas A Rau

A method of electrolessly depositing copper onto a suitably prepared substrate surface is disclosed in which passivity to an otherwise autocatalytic electroless depositing solution is cured by application of a cathodic current for a brief period of time until autocatalytic deposition commences. The method is suitable for coating surfaces which per se are passive to the depositing solution as well as for coating surfaces which normally are receptive to the autocatalytic deposition and which have been so coated up to a certain point where interruption of the plating thereafter renders the surface passive to further deposition.

Method for electroless deposition of copper on conductive surfaces and

An electroless nickel plating method and composition is disclosed wherein a soluble acetylenic compound is included within the plating bath in small amounts effective to improve the specularity of the nickel deposit without substantially decreasing the electroless plating rate of the bath. The method and compositions of the invention are useful in producing mirror-bright electroless nickel coatings free of haze.

Method and composition for electroless nickel deposition

Apparatus and a method are disclosed for replenishing an electroless plating bath with those of its components which are consumed during plating operation, in order that the concentration of components be maintained as nearly constant as possible in the working bath. The system involves withdrawing from the bath a small sample stream at fixed rate, and subjecting this automatically to a sequence of analyses. The system is particularly adapted to control of electroless copper solutions comprising copper ion, hydroxide and formaldehyde as the consumable components. Sequential analyses are made of the sample stream for these components using instrumentation to control actuators which introduce replenisher solutions into the plating tank in response to signals generated by the instruments whenever deviation occurs from a pre-set level. Standardized test solutions of known concentration and rate of feed are introduced into the test stream to optomize test conditions during the analyses. Changes in bath composition occurring during normal plating operations thus provide changes in instrument readings which are analogs of the concentration of the respective components and signals produced by such readings serve to activate the respective replenisher solution feed controls.

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Bristol, CT, United States of America

Leo J Slominski