Showing papers on "Electroless nickel plating published in 1995"

Study of electroless nickel plating of ceramic particles

Abstract: In the production of aluminum-based metal matrix composites (MMC), the wettability of the reinforcement particulates by the matrix is an important factor. The manufacture of MMC reinforced with alumina particles require the use of specialized fabrication techniques such as rheocasting in order to achieve effective particle incorporation. Several surface treatments have been applied to alumina and other reinforcement particulates in order to modify particle wettability. The aim of this study was to investigate the deposition of Ni-P onto several ceramic particulate surfaces without the use of the conventional sensitization and activation steps. This nickel plating treatment, had the potential to improve the incorporation of alumina particles in aluminum melts, with respect to MMC formation by the plasma transferred arc (PTA) surfacing process.

Effect of Surfactants Addition on the Suspension of PTFE Particles in Electroless Plating Solutions

Abstract: SummaryThis study examines the effect of the presence of a variety of surfactants on the suspension of PTFE particles in electroless nickel plating solutions. It has been identified that the suspension of the particles was improved by the addition of non-ionic surfactants especially in the case of polyoxyethylene nonyl phenyl type surfactants.

Uniform heat distribution apparatus and method for electroless nickel plating in fabrication of thin film head gaps

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.

Effect of electroless nickel plating on fatigue strength of 30CrMoA steel

Abstract: The effect of electroless nickel plating on the fatigue properties of 30CrMoA steel was investigated by means of up and down load fatigue tests, scanning electron microscopy (SEM) and optical metallograph. The results show that electroless Ni-P alloy on quenched and tempered 30CrMoA steel decreases its fatigue strength by 39 percent, but that shot-peening before plating can increase the strength by 30 percent, compared with plating directly, and that the fatigue source appears almost at the interface between the coating and the substrate. On the coating, some parallel cracks vertical to the stress axis form after testing

Process for copper plating a wiring board

Abstract: An electroless nickel plating is used as a primer for electroplating of copper. Preferably, electroless nickel plating is conducted after the surface of aluminum is subjected to nickel substitution with a nickel salt under a strongly acidic condition (pH: 1 or less). More preferably, the nickel substitution is carried out after the oxide film on the surface of aluminum is removed.

Recovery of valuable substances

Abstract: Valuable substances are recovered from a spent electroless nickel plating solution containing a water-soluble nickel salt, organic complexing agent, hypophosphite, phosphite, and alkali metal ion by adding oxalic acid to the plating solution for causing a nickel ion to precipitate as nickel oxalate for removal and recovery; optionally adding a sulfide to the plating solution for causing a heavy metal ion to precipitate as a heavy metal sulfide for removal; adding a mineral acid and calcium oxide, calcium hydroxide, calcium carbonate, calcium sulfate, calcium chloride or a calcium salt of organic acid to the plating solution from which the nickel ion has been removed; firing solids of the solution in air for converting the alkali metal ion into an alkali metal salt of mineral acid, converting phosphorus into hydroxyapatite, and pyrolyzing off the organic material; and pouring a solid mixture of the alkali metal salt of mineral acid and hydroxyapatite into water for dissolving the alkali metal salt of mineral acid in water for separate recovery of hydroxyapatite and the alkali metal salt of mineral acid.

Electroless nickel plating solution and plating method

Abstract: PURPOSE: To obtain an electroless nickel plating solution excellent in fine pattern property by adding a compound having S-S sulfur bond into an electroless nickel plating solution containing a water-soluble nickel salt, a reducing agent and a complexing agent. CONSTITUTION: The compound having S-S sulfur bond is added into the electroless nickel plating solution containing the water-soluble nickel salt, the reducing agent and the complexing agent. As the nickel salt, nickel sulfate, nickel chloride or the like is used and the quantity to be used is preferably 0.01-1mol/l. As the reducing agent, hypophosphorous acid is preferably used by 0.01-1mol/l. As the complexing agent, malic acid or the like is preferably used by 0.01-2mol/l. As the compound having S-S sulfur bond, thiosulfat dithionate, polythionate, dithinite is preferable and the quantity to be added is suitably 0.01-100mg/l. COPYRIGHT: (C)1996,JPO

Electroless nickel plating bath using monoamine-type biodegradable chelating agent

Abstract: PURPOSE: To obtain a plating bath excellent in stability and capable of realizing an Ni plating having a high content of P at a high rate by incorporating a specified monoamine-type biodegradable chelating agent into an electroless Ni plating bath as an effective component. CONSTITUTION: At least one kind of the monoamine-type biodegradable chelating agent shown by the formula (where R is hydrogen or an unsubstituted or substituted hydrocarbonic group, R and R are hydrogen or an unsubstituted or substituted hydrocarbon group, R is hydrogen, -COOM-, -SO3 M or -PO3 M, and M is hydrogen, alkali metal or ammonium group) as a complexing agent is incorporated into an electroless Ni plating bath as the effective component. In this case, 0.2-30mols of the chelating agent is preferably used for 5-500mM of Ni ion, and the plating bath is preferably alkalized by NaOH, KOH or NH4 OH. Further, sodium hypophosphite is used as the reducing agent of the bath, and an Ni coating film having a high content of P is obtained at a high rate.

Method for treating aged electroless nickel plating liquid

Abstract: PURPOSE:To provide a method for treating an aged electroless nickel plating liquid capable of stepwise classifying respective dissolved ions of sodium, sulfate and phosphite ions in the liquid and recovering a separated mother liquor containing valuable components such as nickel and hypophosphite ions as a recyclable plating liquid. CONSTITUTION:This method for treating an aged electroless nickel plating liquid is to successively carry out the first step for adding sulfuric acid to the aged electroless nickel plating liquid, then cooling the resultant liquid, crystallizing and separating Glauber's salt octahydrate, the second step for adding a calcium salt to the separated mother liquor, reacting the resultant mixture at pH<=3, crystallizing and separating the produced hydrous gypsum and the third step for adding slaked lime to the separated mother liquor, reacting both in a weak acidic region, crystallizing and separating the produced calcium phosohite.

Production of printed wiring board

Abstract: PURPOSE:To provide a method for producing a printed wiring board having different types of surface metal plating layers at low cost by eliminating one step for forming a plating resist thereby reducing the material cost and manhour. CONSTITUTION:When a photoresist 2 is formed on an insulating board on which a circuit is formed, screen printing is performed such that the circuit is exposed at a part subjected to first surface plating. It is then dried and a first metal plating layer, i.e., an electroless palladium plating layer 5, is formed. Subsequently, a plating resist 6 is formed on the electroless palladium plating layer 5 and a second surface metal plating layer, i.e., an electroless nickel plating layer 7, is formed on the circuit at a part covered with no plating resist 6, which is eventually stripped off. Consequently, the step for forming the plating resist can be eliminated at the time of formation of the first surface metal plating layer.

Fabrication of nickel film on a glass disk by electroless nickel plating

Abstract: A glass substrate was used in the fabrication of the original optical memory disks, such as CD and CD-ROM. Because of pinholes and corrosion with conventional silvering, electroless nickel film was substituted

Fabrication of Microbump on Aluminum by Electroless Nickel Plating

Abstract: Chip bumping for flip chip and tape automated bonding (TAB) assembly has become increasingly important in microelectronic devices. Several methods using vapor deposition followed by electrolytic deposition to form bumps on a spattered aluminum electrode have been reported. The metallization process can be simplified by use of the electroless plating process. Generally the zincate process is used for electroless nickel plating on aluminum substrate. However, the process can not be applied to the metallization of fine circuits, pads or microbumps with photoresists because photoresist are attacked by the highly alkaline zincate solution. Accordingly, electroless nickel plating on aluminum substrate by methods other than the zincate process have been investigated. As a result, straight-walled bumps of up to approximately 20μm in height and between 20μm to 80μm in cubic area can be formed without damege to the photoresist by nickel displacement followed by electroless plating. In addition, nickel bumps can be more uniformly fabricated on an aluminum substrate initially accelerated with DMAB and followed by electroless nickel plating.

Continuous in-situ regeneration of electroless nickel baths during powder plating

Abstract: Continuous addition of nickel to an electroless nickel plating bath, equivalent to ∼18 turnovers of the original nickel content, was made without performance deterioration. Plating was conducted on 118-μm powders at loadings of 100 g/dm 3 or ∼2 m 2 /dm 3 . The formation and precipitation of nickel orthophosphite was prevented by continuous addition of lactic acid to control the free nickel ion activity. Nickel activities with lactic acid additions were determined from EMF measurements on nickel substrates. Stress and toughness measurements of the deposits showed that addition of lactic acid increased the tensile stress in the deposit and decreased the toughness. These effects were overcome by lowering the operating pH of the electroless process.

Printed wiring board and manufacture thereof

Abstract: PURPOSE:To provide the title manufacturing method having high bond properties of copper plating onto aluminum as well as printed wiring board by a method wherein electroless nickel plating step as preprocessing is performed in order to copper-plate the aluminum of an inermediate layer circuit of multilayered printed wiring board using the aluminum on a part of a conductor. CONSTITUTION:Copper foil circuits 3 are formed on both surface and rear surface of a resin laminated board 2 containing multilayered aluminum intermediate layer circuits 1. Before the formation of a through hole copper plating layer 6 from the through hole 4 inner wall surface of this laminated board to the surface and rear surface layer, an electroless nickel plating layer 5 as an underneath layer is formed. Due to the adoption of the electroless nickel plating as the underneath layer of the copper electroplating having the bond properties onto both aluminum and copper plating, excellent copper plating is to be made feasible. Especially, the bond properties can be furthermore enhanced by removing the oxide film on the aluminum surface before the electrolytic nickel plating step as well as substituting the aluminum surface with nickel under strong acidity.

Electroless composite planting device

Abstract: PURPOSE:To easily and uniformly disperse grains in a plating tank to suppress a run away reacton by forming the plating device with a first tank contg. an electroless nickel plating soln. and a second tank contg. a heating medium, covering the periphery of the first tank and heating the plating soln. indirectly. CONSTITUTION:A composite plating bath, in which grains are dispersed in an electroless nickel plating soln. to conduct plating by chemical reduction, is used to apply electroless nickel composite plating to a material to be plated. At this time, the composite plating bath consists of an inner tank 2 contg. a plating soln. and an outer tank 1 covering the periphery of the tank 2 and contg. a heating medium to indirectly heat the plating soln. in the tank 2. The outside of the outer tank 1 is supported by struts 3, the tank 2 has a conical bottom 4 at an incliniation of >=45 deg., and a plating soln. circulating pipe 5 is fixed to the tip of the bottom 4. As a result, the plating film forming rate is accurately controlled without complicating the device structure.

Mechanism parts and formation of film thereon

Abstract: PURPOSE:To produce mechanism parts capable of securely operating over a long period by successively laminating an electroless nickel plating substrate and a ceramic layer at least on either contact face of mechanism parts mechanically connected and mutually contacted rotatably and slidingly. CONSTITUTION:A substrate 21 is formed on parts 20 such as a roller and a pawl by electroless Ni-B plating treatment, and its hardness is increased by heat treatment. Next, a ceramic film 22 of TiC or the like is formed on the substrate 21 by a physical deposition method or the like. Thus, the mechanism parts sufficiently withstanding even if being used for a part subjected to high bearing pressure over a long period can be obtd.

Printed wiring board and manufacture thereof

Abstract: PURPOSE:To enable a printed wiring board to be enhanced in abrasion resistance and solderability and lessened in cost by a method wherein gold and palladium islands are mixedly disposed on a nickel plating film on a conductor pattern. CONSTITUTION:A board 1 on which a conductor pattern is formed is plated with nickel through an electroless plating method to be provided with an electroless nickel plating 4. The board 1 provided with the electroless nickel plating 4 is subjected to substitution-type electroless gold plating and substitution-type electroless palladium plating. At this point, either of substitution-type electroless gold plating and substitution-type electroless palladium plating may precede the other. That is, Au 6 formed through substitution- type electroless gold plating and Pd 5 formed through substitution-type electroless palladium plating are disposed in spots and separately exposed on a surface as Au 6 is not covered with Pd 5 or vice versa.

Electroless nickel plating method

Abstract: PURPOSE: To recycle a recovered mother liquor as a plating solution and a pH adjuster by allowing a phosphite in an aged electroless nickel plating solution to react with calcium carbonate to be precipitated and removed. CONSTITUTION: This electroless nickel plating is performed by using a plating solution having a basic composition using nickel hydroxide, nickel carbonate or nickel hypophosphite as a nickel source and hypophosphorous acid or nickel hypophosphite as a reducing agent in combination. At this time, the phosphite is accumulated in the aged plating solution by the oxidation of the hypophosphite. The phosphite is allowed to react with calcium carbonate or calcium hydroxide in a range of pH6-9 at room temp. and the formed precipitated calcium phosphite is separated and removed. In such a case, the concn. of calcium ion dissolved in the recovered mother liquor is preferably controlled to ≤0.1g/l. Therefore, if necessary, the recovered mother liquor is concentrated by heating to separate and remove calcium phosphite again. COPYRIGHT: (C)1996,JPO

Foaming resin mold and manufacture thereof

Abstract: PURPOSE:To remarkably improve the releasability of a foaming resin molded article by a method wherein composite film layer, which is produced through the dispersed eutectoid of finely divided polytetrafluoroethylene particles in Ni-P matrix formed by electroless nickel plating, is formed on the surface of mold base material. CONSTITUTION:The mold concerned has composite film layer 3, which is produced through the uniformly dispersed eutectoid of finely divided polytetrafluoroethylene(PTFE) particle in electroless plating plated through ground layer 2 on the surface 11 of the base of mold base material 1 such as aluminum alloy or the like. At the formation of the composite film layer 3, the base material 1 is buffed, cleansed with ethane and degreased and cleaned with weak alkali so as to form the ground layer 2 for zinc film on the surface 11 of the base. Next, PTFE is dispersed in electroless nickel plating solution having hypophosphate as reducer. After that, composite film layer 3 is preferably formed by directly immersing the base material 1, on which the ground layer 2 is formed, in the mixed liquid just mentioned above at normal temperature for 10-24 hours.

Method for electroless nickel plating aluminum or aluminum alloy

Abstract: PURPOSE:To provide an electroless nickel plating method capable of applying a lustrous nickel plating film having high adhesive strength and an extremely smooth surface on an aluminum or aluminum alloy. CONSTITUTION:An aluminum or aluminum alloy is anodized by using phosphoric acid or pyrophosphoric acid as the treating bath and using an AC current or a reversing current as the current to form an anodic oxide film having 0.05-0.20mum thickness measured by ESCA on the aluminum or aluminum alloy, then a catalyst nucleus is deposited on the film, and then electroless plating is applied.

Method for regenerating used electroless nickel plating solution and device therefor

Abstract: PURPOSE:To selectively remove phosphorous acid compds. from a used electroless Ni plating soln. without precipitating Ni ions and to reutilize the used soln. by adding calcium hydroxide as a treating agent to the used soln. CONSTITUTION:Ammonium hydroxide is added to a used electroless Ni plating soln. contg. an oxidized hypophosphite by 0.2-4mol, preferably 1.8-2.2mol per 1mol Ni ions in the used soln. and then a phosphorous acid treating agent contg. one or more of hydroxides of Ca, Ba and Sr is added. Phosphorous acid compds. are selectively removed from the used soln. without precipitating Ni ions and the used soln. is reutilized.

Electrolytic Regeneration of Contaminated Electroless Nickel Plating Baths

Abstract: : Electroless nickel (EN) plating is used to apply a protective coating to a substrate without the use of an electric current. Following a catalytic activation step, a nickel phosphorous alloy (NiP) is deposited through chemical reactions on the surface of the part. The advantages over other metal coatings include: (1) coating uniformity, (2) corrosion resistance, (3) wear resistance, (4) desirable magnetic and electrical properties, and (5) indifference to part shape. The most common nickel source is nickel sulfate. Nickel ions are reduced to nickel metal by accepting electrons from an electron donor, typically hypophosphite, present in solution as sodium hypophosphite. Some of the hypophosphite is reduced to phosphorous, and is co-deposited with nickel to form a NiP alloy. As the nickel is plated onto the part, the concentrations of nickel and hypophosphite in the bath decrease. Nickel sulfate and sodium hypophosphite are periodically added to replenish these losses. When 100 percent of the original nickel has been replaced, this is termed a metal turnover (MTO).

Method for recovering valuable material

Abstract: PURPOSE:To separate and recover a valuable material without discharging a pollutant by treating a waste electroless nickel plating soln with oxalic acid, removing the precipitate, then adding mineral acid and a calcium compd and firing the obtained precipitate in the air CONSTITUTION:Oxalic acid is added to a waste electroless nickel plating soln to convert the nickel ion to nickel oxalate, which is precipitated, filtered off and recovered Mineral acid and a calcium compd are added to the plating soln free from nickel ion The water is vaporized off, the solid is fired at 700-870 degC in the air to convert the alkalm metal ion to the alkalm metal salt of the mineral acid and the phosphorus in the hypophosphite and phosphite to hydroxyapatite, and the org matter (nickel complexing agent) is removed by thermal decomposition The solid mixture of the alkali metal salt of mineral acid and hydroxyapatite is then introduced into water to dissolve the metal salt in water, and the hydroxyapatite and metal salt are separated and recovered

Electroless nickel plating solution

Abstract: PURPOSE:To conveniently and economically prevent mold from growing in an electroless nickel plating soln. with a high productivity and obtain the soln. capable of forming a highly reliable coating film by incorporating a nickel source, complexing agent, reducing agent and copper as an antiseptic. CONSTITUTION:This electroless nickel plating soln. contains a nickel source, complexing agent, reducing agent and copper as an antiseptic, hence the molding of the soln. is suppressed, a defective plating film is not formed, and the pipeline is not clogged. The copper concn. is preferably controlled to <=10mg/l, and the upper limit is determined by the allowable copper concn. in the nickel coating film. Easily-soluble copper sulfate, copper chloride, etc., are preferably used as the copper source.

Thin film load cell

Abstract: PURPOSE:To obtain a load cell of a precise shape by treating the whole surface of a strain generating body by way of an electroless nickel plating and forming an etching barrier so as not to dissolve the strain generating body at the etching time. CONSTITUTION:An aluminum alloy A2024 is mechanically processed into a strain generating body 1 with a strain generating part. A face where a pattern is to be formed is ground, and a nickel plating 2 as an etching barrier is formed 13mum thick on the whole surface in an electroless plating method. Then, a polyimide 3 is spin-coated 5mum thick as the insulating coating, which is thermally treated. An iron-chromium alloy 4 is formed 2000Angstrom as a functional metallic thin film over the surface and further, a palladium 5 and a gold 6 are coated respectively 2000Angstrom and 5000Angstrom as an electrode film, thereby to obtain a coated base body. A pattern is formed by a photoresist on a substrate with the electrode. Thereafter, the substrate is washed with water and thermally treated at 300 deg.C for one hour to adjust a temperature coefficient. The load cell is obtained in this manner.