Showing papers on "Electroless nickel plating published in 1971"

A New Technique for Investigating the Electrochemical Behavior of Electroless Plating Baths and the Mechanism of Electroless Nickel Plating

Abstract: The electrochemical potential of electroless nickel and electroless cobalt plating baths can be altered by the addition of a variety of chemical compounds to the baths. At the same time, the metal‐to‐phosphorus ratio in the deposit is altered. This behavior has been studied for a series of baths using typical accelerators including thiourea, glycine, and formate; each of these represents a different type of accelerator characteristic. A Tafel‐like behavior was observed to apply for the deposition of nickel (or cobalt) and also for the deposition of phosphorus. Therefore, given a suitable reference point, the plating rate and metal‐to‐phosphorus ratio can be predicted from the measured potential. A model based on a modified hydride mechanism is proposed for the electroless deposition of nickel‐phosphorus. With the help of this model, the hydrogen evolved during deposition can be quantitatively accounted for.

The application of electrochemical methods to the study of the electroless nickel deposition from hypophosphite solutions

Abstract: The rotating disk electrode has been used for the study of the electroless nickel plating from an acid bath strongly buffered by acetate. The variations of the mixed potential with the temperature have been investigated, and explained by means of polarization curves. These latter present an anodic peak which is typical of the electroless nickel deposition. The polarization resistance measurements allow a direct determination of the plating rate. All these experiments, related to mechanical measurements of plating rate, show the important inhibitor effect of the dissolved oxygen on the deposition reaction. The preliminary study of the faradaic impedance of the metal-electrolyte interface shows that the deposit occurs with not less than two heterogeneous steps, involving an adsorbed intermediate species, which could be NiOHads.

Electroless nickel plating

Abstract: THE SUBJECT MATTER OF THIS INVENTION IS AN ELECTROLESS NICKEL PLATING SOLUTION ESPECIALLY FORMULATED FOR NICKEL PLATING ALUMINUM ALLOYS, ALUMINUM IS A DIFFICULT METAL TO PLATE FROM AN ELECTROLESS BATH BECAUSE ALUMINUM IS ACTIVE AND DEPOSITION OVER ALUMINUM TAKES PLACE AT A RAPID RATE. AS A RESULT, THERE IS EXCESSIVE GASSING AT THE ALUMINUM INTERFACE RESULTING IN MIGRATION OF SMUT PARTICLES FROM THE ALUMINUM SURFACES INTO THE PLATING BATH. THESE PARTICLES ACT AS NUCLEI FOR DEPOSITION OF NICKEL RESULTING IN SPONTANEOUS DECOMPOSITION (TRIGGERING) OF THE BATH AND LOSSS THEREOF, AS WELL AS PLATE-OUT ON WALLS OF THE PLATING TANK, RACKS AND THE LIKE. THE INVENTION OVERCOMES THESE DIFFICULTIES BY ADDITION OF AN UNSATURATED CARBOXYLIC ACID TO THE SOLUTION ALONE OR PREFERABLY IN COMBINATION WITH A SECOND STABILIZER. THE ACID ACTS TO SUPPRESS THE RATE OF DEPOSITION OVER ALUMINUM DECREASING GAS EVOLUTION AND MIGRATION OF SMUT INTO THE SOLUTION. AS A RESULT, TRIGGERING OF THE SOLUTION IS RETARDED.

Electroless nickel solution

Abstract: THE INVENTION RELATES TO ELECTROLESS NICKEL SOLUTIONS CHARACTERIZED BY THE ADDITION OF A SMALL BUT EFFECTIVE AMOUNT OF A SOURCE OF IODATE IONS FOR INCREASED BATH STABILITY. IT IS KNOWN IN THE ART THAT SOLUTIONS FOR ELECTROLESS NICKEL PLATING ARE UNSTABLE AND TEND TO DECOMPOSE WITH USE. IT IS ALSO KNOWN THAT DECOMPOSITION CAN BE RETARDED AND THE USEFUL LIFE OF A PLATING SOLUTION INCREASED BY THE ADDITION OF VARIOUS ADDITIVES, FREQUENTLY CATALYTIC POISONS, IN VERY SMALL CONCENTRATIONS. IN ACCORDANCE WITH THE PRESENT INVENTION, IT HAS BEEN FOUND THAT THE STABILITY OF AN ELECTROLESS NICKEL PLATING SOLUTION CAN BE SUBSTANTIALLY INCREASED BY THE ADDITION OF A SOURCE OF CUPROUS IONS.

Electroless nickel plating process

Abstract: A METHOD FOR NICKEL PLATING CERAMIC PARTS HAVING REFRACTORY-METALIZED AREAS WHEREIN A THIN, POSSIBLY DISCONTINUOUS, COATING OF NICKEL IS PLACED ON THE PART BY BURNISHING OR TUMBLING. THEREAFTER, THE PART IS ELECTROLESSLY PLATED WITH A EUTECTIC NICKEL-PHOSPHOROUS COMPOSITION. THE COATED PARTS ARE HEATED UNTIL THE COMPOSITION MELTS AND RUNS OFF OF ONLY THE CERAMIC, HAVING THE REFRACTORYMETALIZED AREAS UNIFORMLY NICKEL PLATED REGARDLESS OF AREA.

Apparatus for finishing patterns and core boxes

Abstract: An apparatus for finishing patterns and core boxes which are used under abrasive conditions and in production operations. The invention concerns the formation of an electroless nickel plating on at least the surface portions of the patterns and core boxes which are subject to wear because of repeated contact with molding and core forming materials. The electroless nickel solution is contained in a holding tank comprising a large inert plastic structure supported by surrounding insulating walls. The plastic tank is removable so that a clean tank can be utilized at all times thereby increasing the efficiency and effectiveness of the nickel plating operation. A circulating system including a heat exchanger and filter means is employed to provide maximum efficiency with respect to the use of the plating solution.

A New Technique for Investigating the Electrochemical Behaviour of Electroless Plating Baths and the Mechanism of Electroless Nickel Plating

Abstract: The electrochemical potential of electroless nickel and electroless cobalt plating baths can be altered by the addition of a variety of chemical compounds to the baths. At the same time the metal-t...

Chemical nickel plating bath and process

Abstract: 1,243,134 Electroless nickel plating TEXAS INSTRUMENTS Inc June 17, 1969 [July 29, 1968], No 30592/69 Heading C7F An electroless nickel-hyposphosphite plating bath contains glutamic acid or a glutamate The bath may comprise Ni ions 0A079 to 0A189 moles/l, hypophosphite ions 0A132 to 0A297 moles/1, glutamate ions at least twice that of the Ni ions, succinate ions at least twice that of the Ni ions and ammonium thiocyanate 0A3 to 0A6 pp m, temperature 170‹ F to boiling and pH 4A0 to 9A0 The glutamate may be monoammonium, monosodium, monopotassium and calcium glutamates Thiourea may be added as a stabilizer The substrate may be Cu, Fe, Co, Ni, Pd, Pt, Ag, Au, Al, B or plastics activated with Pd The constituents of the bath may be prepared as a dry mix which may be pelleted or packaged in water-soluble plastics bags

Application of Electroless Nickel Plating to Commercial Practice

Abstract: With the rapid expansion of the use of electroless nickel plating in industry the authors have made a detailed assessment of: (1) plant considerations; (2) solution types available; (3) required pr...