Abstract: A method of providing nickel barrier end terminations for a zinc oxide semiconductor device with exposed body surfaces and end terminal regions, in which the device is controllably reacted with a nickel plating solution only on an exposed end terminal region and thereafter provided with a final tin or tin-lead termination.

Abstract: An improved fluxing method for the galvanization of steel, particularly batch galvanization, is disclosed. In this process, a metallic element is deposited (for example, by electroless plating) on the surface of the steel sheet or other article prior to its being dipped in the galvanization bath. Preferred metals for use in this fluxing process are tin, copper, nickel, with tin being more preferred, and mixtures of copper and tin being most preferred. This metallic film layer has a thickness between about 5 and about 50 nm. The process of the present invention provides a number of benefits when compared to conventional fluxing processes: for example, it is compatible with the inclusion of aluminum in the galvanization bath; it permits a greater time delay between the fluxing and galvanization operations; and it eliminates the formation of hydrogen chloride or other toxic fumes when the fluxed article is dipped in the molten zinc galvanization bath.

Abstract: A process for selective electroless plating onto a substrate, including providing a substrate having at least a catalytic surface; providing a plating gel comprising a carrier vehicle, an electroless platable metal compound capable of providing metal ions to the carrier vehicle at a specific pH, a reducing agent, and a polymeric thickening agent; applying said plating gel to the substrate surface in a selected pattern, and inducing plating of said metal on the substrate surface in said selected pattern. A stabilizer, and/or buffering and/or organic chelating agent, and/or surfactant and/or a humectant may be included in the plating gel. Preferably the metal compound is a gold complex, and the substrate is aluminum nitride.

Abstract: The present invention provides methods of electrolessly depositing metal onto the surfaces of electronic components using an enclosable single vessel. The methods of the present invention include contacting the electronic components with an activation solution followed by contacting the electronic components with a metal deposition solution. In a preferred embodiment of the present invention, the oxygen levels in the activation solution and metal deposition solution are controlled in a manner for improved processing results. In another preferred embodiment of the present invention, the activation and metal deposition solutions are used one time without reuse.

Abstract: A method for preventing formation of a "bridge" is provided for electrolessly plated nickel or gold between copper patterns. A circuit board having a copper pattern is immersed in a pretreatment solution containing thiosulfate for electroless nickel plating, or the pretreatment solution is sprayed over the board. The pretreatment solution may be incorporated with an additive, such as a pH adjustor, complexing agent, surfactant or corrosion inhibitor.

Abstract: A process for the co-deposition of fluorinated carbon and diamond material with electroless metal in which the electroless plating bath is formulated to contain an aqueous dispersion of the fluorinated carbon, the finely divided diamond material and an electroless metal salt in aqueous suspension. the plating bath can be used to plate workpieces wherein the fluorinated carbon and diamond material are co-deposited in a plated electroless metal matrix. It has been found that the use of a finely divided diamond material having an average diameter less than 10 nm provides not only improved bath stability but also facilitates the codeposition of the diamond material and fluorinated carbon with the electroless metal.

Abstract: A medium-P/high-P type Ni--P plating coating, the hardness of which can be furthermore enhanced by heat treating, is used for plating on the surface of a sliding member. However, its wear resistance does not arrive at the desired level. In addition, although the P content of the conventional Ni--P--B electroless plating coating is lower than that of Ni--P electroless plating coating, P considerably disordered the crystallinity of Ni crystals and hence impaired the sliding characteristics. There is provided as a Ni--P--B electroless plating coating, which can eliminate the above described problems, a plating coating containing from 0.05 to 5% by weight of P and from 0.01 to 0.05% by weight of B. Furthermore, barrel polishing, shot blasting, laser-beam irradiation, high-frequency induction heating and the like are applied to the plating coating.

Abstract: A process is provided for enhancing the wear resistance of aluminum and other materials by depositing on the substrate a nickel, cobalt, phosphorous alloy coating using an electroless plating bath to provide a plated alloy having a cobalt content of at least about 20% by weight and a % Co/% P weight ratio of at least about 5. A preferred bath contains an effective amount of glycolic acid or salts thereof. The alloy deposit is preferably plated over a zincated aluminum substrate.

Abstract: An electrolytic process and apparatus which can operate in a hydrogen reaction chamber at a hydrogen reaction rate corresponding to the increase in the rate of production of hydrogen accompanying the increase in the electrolysis rate and maintain the current efficiency at a very high value with respect to the electrolytic current for producing hydrogen and a process for the production of an electrode for this purpose.

Abstract: An electroless plating apparatus heats a plating bath solution with precise uniformity and avoids localized high temperatures within the bath. The electroless plating apparatus achieves this performance using two solution tanks included an inner tank nested inside an outer tank. A distributed heating element encases a plurality of surfaces of the outer tank, which contains an ethylene glycol solution. The inner tank contains a plating bath solution. A substrate is placed inside the inner tank for plating. Each of the outer tank and the inner tank include a device for evenly distributing the applied heat. In one embodiment, the outer tank heat distributing device is a pump which mixes the ethylene glycol solution. The inner tank heat distributing device is a pump which recirculates plating bath solution, applying returning solution via a sparger.

Abstract: The invention is directed to corrosion and wear resistant metallic coatings containing nickel and boron. The coatings are preferably deposited on catalytically active substrates from an electroless coating bath containing nickel ions, lead tungstate as a stabilizer, a metal ion complexing agent, and a borohydride reducing agent, at a pH of about 10 to about 14. With post-coating heat treatment the coated surfaces exhibit hardness levels as high as about 2200 Knoop.

Abstract: Orthophosphite ions produced by oxidation of hypophosphite in an electroless nickel plating bath can be removed by precipitation with an alkali metal or alkaline earth metal cation such as calcium. In order to avoid the precipitation of calcium sulfate and the generation of large amounts of particulates in the bath, nickel sulfate can be replaced by a nickel salt of an alkylsulfonic acid or hypophosphorous acid, whose anion forms a soluble salt with an alkali metal or alkaline earth metal cation.

Abstract: A continuous ceramic composite plating method for long doctor base materials which comprises a degreasing step, rinsing step, acid immersion step, rinsing step, electroless ceramic composite nickel plating step, plating solution collection step, rinsing step, and drying step between a first step of supplying continuously one or a plurality of long doctor blade base materials held on one or a plurality of material reels spirally while the blade surfaces are maintained in a horizontal direction with respect to the surface of a solution; and a predetermined interval therebetween is maintained and a final step of taking up continuously the one or plurality of blade base materials on a plurality of corresponding take-up reels while the one or plurality of blade base materials are cramped by a plurality of pinch rolls, as well as an apparatus therefor. The doctor blades can be plated continuously and efficiently.

Abstract: Method for plating an electroless nickel phosphorus containing alloy deposit on a substrate where the deposit has a high weight percent of phosphorus above 8 or 10 weigh percent and is plated at high deposition rates above 10 and up to 25 micrometers per hour and where the plating deposition is conducted in the presence of a nickel chelating agent having a stability constant, log K.sub.a, above 3 such as citric acid and at a pH of from about 5.0 to about 8.0.

Abstract: A flexible meshing type gear device 1 has an internal gear 2 having internal teeth 21, a flexible external gear 3 having external teeth 31, and a wave generator 4. Only the internal teeth 21 of the internal gear 2 are formed thereon with a metal plated coating 21a. Further, a tooth profile 211 of the internal teeth 21 of the rigid internal gear 2 before metal plating is modified from a desired tooth profile of the internal teeth so that a tooth profile 212 defined by a surface of the internal teeth 21 after metal plating corresponds substantially to the desired tooth profile of the internal teeth for assuring a proper meshing between the internal and external gears. Accordingly, a flexible meshing type gear device having a high wear resistance can be realized while maintaining a high fatigue strength of the external gear and a proper meshing between gears.

Abstract: A process for producing a low-stress electrolessly deposited layer of nickel yielding a clean nickel film and having a wettable surface is described. Diffusion is performed in a non-oxidizing environment, using a gas mixture containing nitrogen. The diffusion temperature is optimally set at a temperature of at least 500.degree. C., i.e., at least 150.degree. C. below typical prior art diffusion temperatures. The presence of nitrogen during diffusion changes the direction of the outgoing born away from the surface of the film, and eliminates the requirement that the nickel film be plated on refractory metal that contains glass, which was previously required to provide a media for the boron to diffuse into it for its subsequent removal.

Abstract: An extrusion die for forming a honeycomb structure such as a catalyst carrier of a catalytic converter for internal combustion engines is provided. The extrusion die includes material inlet ports and latticed slits. The slits are formed in a die base and have first inner walls leading to an outer surface of the die base and second inner walls leading to the material inlet ports, respectively. Metal-plated layers are formed on the first inner walls of the slits to define outlets of the die and have the width smaller than those of the second inner walls of the slits, respectively. This die structure facilities easy extrusion of the honeycomb structure made up by thin honeycomb walls with a smaller extrusion resistance.

Abstract: A process of electrolessly metallizing a body on the surface thereof with a metal coating incorporating particulate matter therein, which process comprises contacting the surface of said body with a stable electroless metallizing bath comprising a metal salt, an electroless reducing agent, a complexing agent, an electroless plating stabilizer, a quantity of particulate matter which is essentially insoluble or sparingly soluble in the metallizing bath, and a particulate matter stabilizer (PMS), and maintaining said particulate matter in suspension in said metallizing bath during the metallizing of said body for a time sufficient to produce a metallic coating with said particulate matter dispersed therein.

Abstract: A plating jig for plating a corrugated tube includes a linear center rod, a circular rod helically formed with the center rod as its center axis, support rods each having a base fixed to the center rod and an end extended in the radial direction of the circular rod, and suspensions provided at the ends of the support rods respectively, extended in the same direction as the center rod and connected to the one-end side outer circumferential surface of the circular rod.

Abstract: A zinciferous plated steel sheet which comprises a steel sheet, at least one zinciferous plating layer formed on at least one surface of the steel sheet, and an Fe--Ni--O film as an uppermost layer formed on the zinciferous plating layer. The total quantity of metallic elements in the Fe--Ni--O film is within a range of from 10 to 1,500 mg/m.sup.2, and the oxygen content in the Fe--Ni--O film is within a range of from 0.5 to under 30 wt. %. The ratio of the iron content (g/l) relative to the total quantity of the iron content (g/l) and the nickel content (g/l) in the Fe--Ni--O film is preferably within a range of from over 0 to under 1.0.

Abstract: A copper-tungsten or copper-molybdenum substrate is plated with a nickel/gold plating by first activating a surface of the substrate. In activating, the surface is contacted to a concentrated alkaline solution at elevated temperature, and then to a concentrated acidic solution. The surface is thereafter plated with a nickel strike layer, plated with a nickel primary layer overlying the nickel strike layer, sintered, re-activated in a concentrated acidic solution, plated with a nickel secondary layer overlying the nickel primary layer, and plated with a gold layer overlying the nickel secondary layer.

Abstract: A process for depositing catalytically active platinum metal layers from an ionogenic, acidic, platinum metal ions-containing solution which further contains sulfonic acid. This activation leads to more uniform catalyst layers with greater surfaces which are catalytically more efficient. The process according to the invention can be implemented in any chemical process utilizing platinum metal catalysts, e.g. chemical synthesis, environment applications or metallization of surfaces.

Abstract: In the manufacture of a microelectronic component having metallic features on a polyimide layer, the metallic features being spaced from one another by gaps, at least some of which gaps have widths in a range from about one micron to about 500 microns, corrosion protection is provided by plating those features by electroless deposition of a nickel-phosphorus alloy forming a layer having a thickness in a range from about 200 .ANG. to about 3000 .ANG., at a rate of about 100 .ANG. per minute, in an aqueous plating bath comprising nickel sulfate hexahydrate in an amount of about 5.5 grams per liter, sodium hypophosphite in an amount of about six grams per liter, boric acid in an amount of about 30 grams per liter, sodium citrate in an amount of about 45 grams per liter, lead acetate in an amount of about one part per million by weight of lead, and a surfactant in an amount of about 0.1 grams per liter. The bath has a temperature of about 72.degree. C. and a pH of about 8.1.

Abstract: A method of selectively fabricating metallization on a dielectric substrate is disclosed. A seed layer is sputtered on a polymer dielectric, a patterned photoresist mask is disposed over the seed layer, exposed portions of the seed layer are etched, the photoresist is stripped, and copper is deposited without a mask by electroless plating on the unetched seed layer to form well-adhering high density copper lines without exposing the photoresist to the electroless bath.

Abstract: A method for the deposition of a diamond film, which includes the steps of immersing metallic or nonmetallic substrate in and electroless nickel plating bath containing a reducing agent to form a nickel layer; and depositing the diamond film on the electroless nickel plated substrate. As a result, employing electroless plating to form an inter layer is improved. In addition, the diamond film can be formed regardless of the type of materials used.

Abstract: A method producing a coating on a substrate by aluminizing, chromizing or siliconizing the substrate, and depositing on the coated substrate by electrolytic or electroless deposition a metal matrix M.sub.1 from a bath containing particles of CrAlM.sub.2 to co-deposit the particles with the matrix as M.sub.1 CrAlM.sub.2, where M.sub.1 is Ni, Co or Fe or two or all of these elements and M.sub.2 is Y, Si, Ti, Hf, Ga, Nb, Mn, Pt, a rare earth element or two or more of these elements. Preferably, the method includes platinum aluminizing of the substrate. Heat treatments may be incorporated before and after deposition of the M.sub.1 CrAlM.sub.2. The deposition of the M.sub.1 CrAlM.sub.2 is carried out at a current density of less than 5 mA per square centimeter. Preferably, the deposition forms a M.sub.1 CrAlM.sub.2 layer less than 50 microns thick, and occurs at a bath loading of less than 40 grams per liter of the particles.

Abstract: A process for preparing a solder bump can be prepared by the following procedure. The chip package was cleaned with an alkali or acid solution followed by Zn displacement (zincating)in a displacement solution which comprises NaOH, Z.sub.n o, potassium sodium tartrate and sodium nitrate. After zinc displacement the chip package was performed the electroless Ni--Cu--P deposit in the strong reducing solution which contains NaH.sub.2 PO.sub.2. The chip package deposited with Ni--Cu--P was then dipped into an organic solution as flux which is a mixture of the stearic acid and glutamic acid. Finally, dip soldering of the Ni--Cu--P deposited chip packages in a molten solder bath at a temperature 40.degree..about.80.degree. C. higher than the melting point of the corresponding Pb--Sn alloy.

Abstract: A wobble plate in a wobble plate compressor has a bevel gear positioned at a central portion thereof. The bevel gear is provided with a centered ball seat. A second bevel gear is supported on the cylinder block and also has a centered ball seat. A bearing ball is seated in both of the ball seats so that the wobble plate nutates about the ball. At least one of the bevel gears is coated with electroless composite plating layer having a self-lubricative material, such as polytetrafluoroethylene (PTFE), dispersed therein. Consequently, the bevel gears have low frictional resistance, high hardness and improved anti-seizure characteristics.

Abstract: Metal hydrides are activated by an electrochemical procedure. In this procedure, a bulk sample of the corresponding metal is immersed in an aqueous electrolyte and contacted by a cathode. Current passed through the aqueous electrolyte causes electrolysis of the water and a concomitant reaction with the formation of metal hydride. As a result, the metal hydride is fractured and smaller particles result. Additionally, the resulting metal hydride has a substantial amount of absorbed hydrogen. A novel plating method, taking advantage of the reducing power of hydrogen absorbed in a metal hydride, is useful to encapsulate such metal hydride with a variety of metals. Therefore, such hydrides are uniformly coated by using plating solutions without the standard reducing agent and stabilizer.

Abstract: In a process for the electroless plating of nickel onto a substrate made of aluminum or an aluminum alloy, an aqueous acidic solution containing as an essential component a palladium salt is used as an activator of the substrate prior to the nickel plating of the substrate. The activating solution contains a palladium salt, an alkali metal fluoride or hydrofluoric acid, a carboxylic acid complexing agent, an alkali metal salt of gluconic acid, an iron salt, a nickel salt, and deionized water.

Abstract: An electroless plating bath for forming black coatings containing a nickel salt and a reducing agent, which further contains a sulfur-containing compound, zinc ions and optionally microparticles, and a method for forming black coatings by electroless plating, wherein an article to be plated is immersed in the plating bath for a certain period of time, which provide black plated coatings without any post-treatments for blackening. Also provided is an article having an electrolessly plated black coating formed by the method.

Abstract: The improved method comprises contacting a substrate 5 at least once by a liquid containing the elements that compose a pure metal or an alloy with which the small holes or recesses 3a in the substrate 5 are to be filled or covered, whereby the liquid wets the inner surfaces of said small holes or recesses 3a while, at the same time, said pure metal or said alloy is deposited on the surface of said substrate 5. The method is capable of filling small holes or covering small recesses in the surface of the substrate 5 with improved efficiency while, at the same time, it improves the heat resistance and materials stability of the part that contains the formed filling or covering layer.

Abstract: A process for the selective variation in density of particulate matter codeposited within metallic matrices deposited onto articles utilizing increased levels of rotation of said articles during plating cycle to attain said selective codeposition density. The attainment of varying densities of codeposited particulate matter in the plated layer along the surface of the substrate is particularly useful in cost reduction and improved product performance.

Abstract: A method is provided for creating gated filament structures for a field emission display. A multi-layer structure is provided that includes a substrate, an insulating layer, a metal gate layer positioned on a top surface of the insulating layer and a gate encapsulation layer positioned on a top surface of the metal gate layer. A plurality of gates are provided and define a plurality of apertures on the top of the insulating layer. A plurality of spacers are formed in the apertures at their edges on the top surface of the insulating layer. The spacers are used as masks for etching the insulating layer and form a plurality of pores in the insulating layer. The pores are plated with a filament material to create a plurality of filaments. The pores can be overplated to create the plurality of filaments. The filaments are vertically self-aligned in the pores.

Abstract: In knitting parts (a jacquard guide needle, a guide, a needle, a tongue, a sinker, a separator, etc.), each having a portion which is brought into contact with a knitting yarn when fitted to a knitting machine to perform knitting, the surface of a portion of a metallic part base material (10) thereof is coated with a compound plating layer (12) made of a non-electrolytic nickel alloy plating layer including minute silicon particles dispersed therein, each of the silicon particles being coated with a hard carbon film. As a result, it is possible to improve the durability of the knitting parts similarly to those in which the surface of the part base material is coated with the hard carbon film and moreover remarkably reduce the processing cost.

Abstract: Silicon and germanium containing materials are used at surface of conductors in electronic devices. Solder can be fluxlessly bonded and wires can be wire bonded to these surfaces. These material are used as a surface coating for lead frames for packaging integrated circuit chips. These materials can be decal transferred onto conductor surfaces or electrolessly or electrolytically disposed thereon.

Abstract: A process is provided for plating zinc die cast substrates with an electroless nickel coating comprising depositing an electrolytic zinc layer on the substrate followed by depositing a first electroless nickel layer on the electrolytic zinc layer using a first alkaline electroless nickel bath and then depositing a finish electroless nickel layer on the first electroless nickel layer using an acidic electroless nickel bath. In a preferred embodiment, a second electroless nickel layer is deposited on the first electroless nickel layer using a second alkaline electroless nickel bath. It is preferred that at least one and preferably all of the electroless nickel baths contain an effective amount of antimony ions to enhance bath stability and metal to metal adhesion. Mechanical cleaning of the zinc die casting before plating is preferred.

Abstract: Printed circuit board having excellent peel strength and conductance resistance is provided with a substrate, a resin insulating layer formed thereon and roughened at its surface, and a conductor formed thereon, in which at least a portion of the conductor is composed of an eutectic metal layer.

Abstract: Electroless nickel baths for producing high hardness nickel alloys "as-deposited" containing phosphorus which are produced using baths employing hypophosphite reducing agents at a particular pH range advantageously above 6 and in the presence of a fluoborate anion. The nickel phosphorus alloys "as-deposited" do not require age or heat treatments to produce high hardness with Vickers Harness Number values above about 700 and generally above about 800 to 900 (VHN.sub.100) and have phosphorus contents below about 4 weight percent and a crystalline nature with crystallite diameters in excess of 60 Angstroms.

Abstract: A method is provided for wire bonding an aluminum wire to a surface of a lead of an electronics package. The method entails a nickel plating process and an ultrasonic bonding process which together cooperate to form a reliable and highly repeatable joint between the wire and the lead member. The ultrasonic bonding process is specifically tailored to the nickel plating produced by the plating process, so as to significantly enhance the bond strength of the resulting ultrasonic bond joint. The plating process is devised to produce a nickel plating which is thicker than that generally practiced, and whose surface is characterized as having a relatively smooth microfinish which unexpectedly serves to enhance the bond strength of the ultrasonic bond joint.

Abstract: A corrosion-resistant fiberglass spinner is prepared by applying consecutive, alternating layers of chromium and nickel to the bores of the spinner, and thereafter thermally interdiffusing the chromium and nickel to form a corrosion-resistant coating.

Abstract: A wobble plate in a wobble plate compressor has a bevel gear positioned at a central portion thereof. The bevel gear is provided with a centered ball seat. A second bevel gear is supported on the cylinder block and also has a centered ball seat. A bearing ball is seated in both of the ball seats so that the wobble plate nutates about the ball. At least one of the bevel gears is coated with electroless composite plating layer having a self-lubricative material, such as polytetrafluoroethylene (PTFE), dispersed therein. Consequently, the bevel gears have low frictional resistance, high hardness and improved anti-seizure characteristics.

Abstract: An improved process is disclosed for treating aluminum for memory disk applications and for producing metal plated aluminum memory disks. It has been found that a solution prepared from methane sulfonic acid and sodium peroxydisulfate can be used as a direct replacement for a nitric acid bath in the processing of aluminum substrates for memory disk application. In accordance with the present invention, the methane sulfonic acid/sodium peroxydisulphate solution can be used to deoxidize the aluminum substrate prior to zinc deposition and also to remove the first zinc film in either alkaline or acid double zinc plating processes.

Abstract: A method of selectively seeding or activating metal interconnections patterned on polyimide dielectric surfaces using an aqueous solution of palladium sulfate, palladium perchlorate, palladium trifluoromethane sulfonate, palladium nitrate or other palladium salts having poorly coordinating counter ions. This strongly selective seeding and the corresponding ability to reliably remove all traces of the seeding material from the polyimide surface eliminates shorting, bridging and reduction of breakdown voltage during electroless plating of a thin layer of nickel or cobalt.

Abstract: A method of producing an oil-free screw compressor has the following steps: preparing a semi-finished metallic female rotor which has a spiral profile, and a semi-finished metallic male rotor which has a spiral profile; forming a metallic coating film containing particles of grinding material on the surface of the semi-finished female rotor; forming, on the surface of the semi-finished male rotor, a coating film of a material softer than the metallic coating film on the female rotor; grinding the surfaces of the semi-finished rotors into predetermined configurations; mounting the ground rotors on bearings so that the rotors are assembled in a rotor casing with a substantially constant spacing held between the axes of the semi-finished rotors; mounting timing gears on the rotors so as to drivingly connect the rotors each other; and driving the rotors by driving means while restraining the back lash in the rotating direction by means of the timing gears and applying a compression load to the rotors so that the

Abstract: The invention relates to improvement in well drilling tools to prevent drilling fluids and solid particles present in a subterranean location from adhering to drilling equipment. A nickel-phosphorus coating is deposited by an electroless plating process on the entire surface of the tool, so as to substantially reduce porosity of the tool and prevent penetration of the foreign matter into the ferrous core of the tool.

Abstract: In a preferred method, a zinc-rich alloy coating is applied to a substrate using an electrolysis deposition solution which contains a metal salt of zinc and a metal salt of nickel each in an amount sufficient to provide a weight ratio of zinc to nickel (Zn:Ni) of at least about 1:1; a phosphorus-containing reducing agent in an amount sufficient to cause reduction of the zinc and the nickel to ions thereof; sufficient complexing agent to maintain the nickel ions and the zinc ions in solution; and a buffer in an amount sufficient to achieve a desired pH. Preferably, the surface of the substrate is pretreated or precatalyzed before deposition by a sensitizing step using tin and an activating step using palladium.

Abstract: A process of electrolessly metallizing a body on the surface thereof with a metal coating incorporating particulate matter therein, which process comprises contacting the surface of said body with a stable electroless metallizing bath comprising a metal salt, an electroless reducing agent, a complexing agent, a quantity of particulate matter which is essentially insoluble or sparingly soluble in the metallizing bath, and a particulate matter stabilizer (PMS), and maintaining said particulate matter in suspension in said metallizing bath during the metallizing of said body for a time sufficient to produce a metallic coating with said particulate matter dispersed therein.

Abstract: Cyanate ester polymer articles, particularly fiber-reinforced, are metallized by electroless deposition preceded by a series of pretreatment steps which improve adhesion of the metal layer or layers. Said steps include aqueous alkali followed by nitric acid treatment. They preferably also include an initial alkaline permanganate treatment, preferably preceded by aqueous alkali.

Abstract: An electroless plating solution comprises nickel ion, a chelating agent for nickel ion, dimethylamine borane, one or more soluble salts of a condensate of an arylsulfonic acid with formalin, and thiodiglycolic acid, and an electroless plating method comprises the step of immersing a substrate to be plated in this electroless plating solution for sufficent time period to form a nickel or nickel alloy layer on the substrate. The electroless plating solution has a high bath stability and is capable of forming an excellent thick deposit free from pits and cracks.