Electroless nickel plating

About: Electroless nickel plating is a research topic. Over the lifetime, 1593 publications have been published within this topic receiving 14940 citations.

Replenishment of electroless nickel solutions

Abstract: This invention concerns replenishment of aqueous electroless nickel plating solutions and to apparatus useful therefor. The process of the invention comprises addition of replenishers in essentially dry form in a manner that avoids triggering of the bath. Typical replenishers that may be added in dry form include one or more of a soluble source of nickel ions such as nickel chloride, a reducing agent for nickel ions, bath stabilizers, brighteners, surfactants and the like. These ingredients may be added singularly or admixed with each other. Essentially dry materials are used for replenishment rather than a solution as in the prior art, to prevent volume growth of the plating solution.

Method for controlling electroless plating bath

Abstract: A method and an apparatus for controlling an electroless plating bath such as an electroless nickel plating bath such that the bath is useable for an extended period of time without remaking are disclosed. The method comprises the steps of: continuously or intermittently measuring the concentration of at least one consumable ingredient of the electroless plating bath, and automatically adding to the plating bath a first replenishing composition essentially consisting of the consumable ingredient after detecting that the measured value has reached a predetermined concentration; while continuously or intermittently measuring one physical property of the electroless plating bath to determine the degree of aging of the bath, and automatically discharging a predetermined volume of the plating solution and automatically adding to the plating bath a second replenishing composition containing unconsumable ingredients in an amount essentially corresponding to the lost amount by the discharging after detecting that the measured value has reached a predetermined value of the physical property.

Electroless deposition of nanosized nickel over graphite substrate with better coating coverage and catalytic activity for fuel cell application

Abstract: Nickel nanoparticles of the size 50−60 nm were deposited on graphite particles by electroless plating. The sensitized and activated graphite powder was used as substrate precursor. The depositions of nickel and under layers of Pd and Sn on graphite particles were characterized by the Field Emission Scanning Electron Microscopy (FESEM), XRD, XPS and Energy Dispersive X-ray (EDX) techniques. The FESEM images have shown the deposition of the nickel nanoparticles. The Zeta particle analyser (ZPA) has inferred about the conductivity and average particle sizes of graphite and nickel/graphite powder. The calculated active surface area and surface coverage of Ni-deposited electrode are 0.15 × 10−2 cm2 and 2.4409 × 10−7 mol cm−2, respectively. The Electrochemical studies of graphite and Sn/graphite, Pd/Sn/graphite and finally the Ni−Pd/Sn/graphite were carried out using cyclic voltammetry (CV) in the potential range between −1.0 and 1.0 (V versus SCE) at the scan rate of 50 mV s−1. The electrocatalytic activity of the catalyst substance was investigated for methanol oxidation in KOH medium. Electrochemical Impedance Spectroscopy (EIS) studies of the above electrodes for methanol oxidation in 0.5 M KOH solution have shown a very small arc in the high-frequency region, which corresponds to low charge resistance and high capacitance. This implied that nickel supported on graphite would be a better electrocatalyst for fuel cell application. Nickel nanoparticles of 50–60 nm size were deposited on graphite substrates by electroless nickel plating. The formation of Ni/graphite powders were proven by SEM, XRD, ZPA, XPES and EDX techniques. A significant electrochemical/catalytic activity of the Ni/graphite electrode was observed by impedance spectroscopy and cyclic voltammetry for methanol oxidation.