Showing papers on "Electroless nickel plating published in 1997"

Electroless nickel plating solution and method

Abstract: To an electroless nickel plating solution comprising a water-soluble nickel salt, a reducing agent, and a complexing agent is added a polythionate or dithionite. The invention also provides a high-build electroless gold plating method comprising the steps of immersing a workpiece in the electroless nickel plating bath, thereby chemically depositing a nickel coating on the workpiece, and immersing the nickel-plated workpiece in an electroless gold plating bath, thereby chemically depositing a gold coating on the workpiece.

Method for electroless nickel plating of metal substrates

Abstract: The present invention relates to a method for plating nickel onto metal substrates. The method broadly comprises the steps of passing the metal substrate to be plated through a dilute organic acid bath solution to remove contaminants and other deleterious materials, agitating the bath solution as the metal substrate passes therethrough, and thereafter electrolessly plating nickel on the surfaces of the metal substrate. The method of the present invention may be used to nickel plate substrates formed from steel, copper and aluminum.

Fabrication of Nickel Microbump on Aluminum using Electroless Nickel Plating

Abstract: Fabrication of nickel microbumps on an aluminum electrode using a nickel displacement and a direct nickel plating process was investigated. Electroless nickel plating reaction with hypophosphite as a reducing agent was not initiated on the aluminum substrate, because aluminum does not have catalytic action on the oxidation of hypophosphite. Accordingly, nickel was initially deposited on the aluminum using nickel displacement plating for the initiation of the electroless plating. Nickel bumps on the aluminum electrode were fabricated by treatment of the nickel displacement plating followed by electroless nickel plating. Nickel microbumps also can be formed on the aluminum electrode without the displacement plating process. Activation of the aluminum surface is an indispensable process to initiate electroless nickel plating. Uniform bumps 20 μm wide and 15 μm high with good configuration were obtained by direct nickel plating after being activated with dimethyl amine borane.

Turbo molecular pump

Abstract: PROBLEM TO BE SOLVED: To keep the temperature of a rotor blade at comparatively low, and enhance its corrosion prevention properties by restraining the rotor blade from being increased in temperature due to a heat source at the intake port side of a turbo-molecular pump SOLUTION: A rotor blade 4 to be rotated at high speed and a stator are provided, at least the end surface 40 at the upstream side of the rotor blade 4 and the surface of a first step 41 at the upstream side of the rotor blade 4, are plated with nickel by means of electroless deposition restraining heat transfer from a heat source at the intake port side to the rotor blade, and composite plating B for forming its lower layer into an electroless nickel plating layer high in corrosion prevention properies enhancing the heat radiation of the rotor blade, and forming its upper layer into an electroless nickel plating layer in which particles high in heat radiation factor are dispersed, is applied to the surface 4a other than the surfaces to which electroless deposition is applied By this constitution, at least the heat radiation factor of the surface at the upstream side of the rotor blade is made low, and the heat radiation factor of the surface at the downstream side of the rotor blade is made high, and the corrosion prevention properties of the surfaces can be enhanced

Electroless Nickel Plating of Magnesium

Abstract: The development of a reliable production process for the electroless nickel plating of magnesium die casting alloy is described. The chemistries of the pre-treatment process and the electroless nickel solution itself are interdependent. SEM, EDX and EPS studies were made of the magnesium surface at various stages in the pre-treatment in an effort to explain the mechanism of adhesion and deposition.

Activation bath for electroless nickel plating

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

Therm-optic analysis of bi-metallic mirrors

Abstract: The optical surfaces of metal mirrors are often plated with electroless nickel to reduce light scattering. The thermalcoefficient of expansion of electroless nickel, 13.5 x 106 rn/rn-K, is significantly different from that of a typical mirrorsubstrate material such as aluminum. A change in temperature produces a "bi-metallic" bending stress in an electrolessnickel plated mirror, which can induce optical surface distortion. Possible solutions to the "bi-metallic" bending effectinclude: metal matrix composites with a thermal coefficient matched to that of the plating, thick mirrors with sufficientstiffness to resist bending, symmetric cross sections producing equal and opposite bending, and plating of both sides of themirror to balance bending deformations. These solutions are compared using a design example from a cryogenic instrument,the Gemini Near Infrared Spectrograph (GNIRS). Deflections are calculated using both finite element and closed formsolutions. The closed form solution produces an order of magnitude estimate, which may not be a reliable guide to the actualtherm-optic performance of a plated metal mirror. More sophisticated analytical techniques, which determine the actual typeof optical surface error, such as focus, piston, and aberration terms, are required to determine the performance of a mirrorundergoing "bi-metallic" bending.Keywords: bi-metallic bending, athermalization, cryogenic optics, metal mirrors, electroless nickel plating, Gemini 8-mtelescope, near-infrared spectrograph, opto-mechanical design

Removal of orthophosphite ions from electroless nickel plating baths

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.

Electroless silver-plated powder and its production

Abstract: PROBLEM TO BE SOLVED: To produce electroless silver-plated powder in which a uniform and dense silver coating film is formed on the surface of powder and excellent in electric conductivity and to provide a method for producing the same. SOLUTION: This electroless silver-plated powder is the one in which copper- coated inorganic or organic grains have a nickel plating coating base layer as a base material, and silver coating film is formed on the surface of the base material by an electroless plating method. This powder is produced by successively executing a primary stage in which the inorganic or organic grains are applied with electroless nickel plating, a secondary stage in which the nickel plating-coated grains are applied with copper plating and a third stage in which the copper plating-coated grains are applied with silver plating.

Method for circulating electroless nickel plating solution

Abstract: A method of circulating an electroless nickel plating solution is characterized in that the system comprises the following process steps effected in the following order: (A) a step of electrolessly plating nickel using a plating solution having nickel hypophosphite contained as a chief chemical material for supplying a plating metal ion Ni 2+ and a hypophosphorous acid ion H 2 PO 2 − acting as a reducing agent; (B) a step of removing HPO 3 2− from a plating solution that has aged in the step (A); (C) a step of desalting the mother liquor separated from the step (B); and (D) a step of adjusting the components of the treated plating solution and then circulating same back into the step (A) of electroless nickel plating According to the present invention, the plating solution is free from the formation and accumulation of a sulfuric acid salt and hence a long service life is ensured and a great advantage in environmental protection is provided

Substrate for mounting semiconductor and its production

Abstract: PROBLEM TO BE SOLVED: To provide a substrate for mounting semiconductors having excellent joining strength of solder ball terminals and solder balls and a process for producing the same. SOLUTION: This substrate for mounting the semiconductors is constituted by forming an electroless nickel plating film on circuits consisting of metals, forming an electroless palladium plating film on the electroless nickel plating film and forming an electroless gold plating film on the electroless palladium plating film. The electroless nickel plating film is a nickel-phosphorus alloy plating film and a nickel-boron alloy film formed thereon. This process for producing the substrate for mounting the semiconductors consists in successively forming the electroless nickel-phosphorus alloy plating film, the electroless nickel-boron alloy plating film, the electroless palladium plating film and the electroless gold plating film on the circuits consisting of the metals. COPYRIGHT: (C)1999,JPO

Effects of Electroless Nickel Plating on Resistivity-temperature Characteristics of (Ba 1- x Pb x )TiO 3 thermistor

Abstract: Effects of electroless nickel plating on resistivity-temperature (R-T) characteristics of (Ba1-xPbx)TiO3 thermistor were studied. Comparison experiments showed that not only the permeation of plating solution, but also the reaction of electroless nickel plating influences the positive temperature coefficient (PTC) effect, and that the two effects are different in nature. It is first proposed in this paper that hydrogen atoms generated in electroless nickel plating may reduce components of PTC ceramics.

A new low-temperature electroless nickel plating process

Abstract: A new low-temperature electroless nickel plating process was developed by adding some inorganic agents to the plating solution, in which citrate acted as complexing agent. With the optimum process determined, high deposition rate was obtained, resulting in a bright deposit with excellent adhesion.

Method of treating electroless plating bath

Abstract: Disclosed is a method of treating an electroless nickel plating bath mainly containing a water-soluble nickel salt, a complexing agent for complexing the nickel salt, and sodium hypophosphite as a reducing agent for reducing the nickel salt, including the steps of:repeatedly regenerating and reusing the electroless nickel plating bath in which a phosphite is accumulated by adding nickel sulfate to the plating bath to produce and precipitate nickel phosphite and separating the nickel phosphite from the plating bath; and adding sulfuric acid or a mixture of sulfuric acid and sodium sulfate to the nickel phosphite separated from the plating bath to convert the nickel phosphite into nickel sulfate and phosphorous acid or NaH 2 PO 3 , and recovering the nickel sulfate. According to this method, it is possible to simply, positively and inexpensively separate phosphite ions, without inclusion of any impurity, from an aged electroless plating bath in which phosphite ions are accumulated in a large amount, and to simply recover nickel sulfate from the nickel phosphite thus separated from the plating bath and effectively use the nickel sulfate as a reactive medium for removing a plating bath component or phosphite ions.

Enhanced sintering of an Fe-Ni-P coated composite powder prepared by electroless nickel plating

Abstract: An Fe-8.2 % Ni-6.0 % P powder was prepared by electroless nickel plating on a carbonyl iron powder, where phosphorous appeared as a contaminant of the plating process. Because of the high phosphorous concentration, persistent liquid phase sintering was effective at temperatures higher than 1000 °C. The sintered microstructure was dramatically different from the conventional approaches, where a low concentration of phosphorous was added in the form of Fe3P. Sintering the alloy at a temperature as low as 1050 °C for 30 min yielded a sintered density of 98.6% theoretical and rounded grains having an average grain size of 53 µm. The rounded grains were surrounded by a large volume fraction of intergranular (Fe,Ni)3P phase, arising from the high phosphorous concentration, which slightly deteriorated the magnetic saturation but significantly increased the electrical resistivity of the alloy. Generally speaking, the magnetic saturation of the sintered alloy was improved with respect to the iron-phosphorus, iron-nickel, or iron-silicon alloys fabricated by powder processing.

Method for nickel plating onto aluminum electrode

Abstract: PROBLEM TO BE SOLVED: To obtain a method for electroless nickel plating onto an aluminum electrode required for formation of a highly reliable electrode. SOLUTION: Nucleus is formed of a deposit 14 of palladium on an aluminum electrode 12 using an activation liquid and a reducing agent, i.e., sodium hypophosphite, is dissolved into pure water. While conditioning the pH in the range of 9.0-12.0 using a sodium hydroxide solution, water is added to produce a solution 15 having total volume of 1000mL. The aluminum electrode 12 of semiconductor element is immersed into the solution 15 and then plated using an oxidation-reduction electroless plating liquid of 80-90 deg.C having pH in the range of 5.0-6.8 thus depositing nickel 16 containing phosphorus on all aluminum electrode 12 of semiconductor element.

Low core loss grain-oriented silicon steel sheet and its production

Abstract: PROBLEM TO BE SOLVED: To improve the core loss of a grain-oriented silicon steel sheet and to improve its corrosion resistance by applying electroless nickel plating to a finish-annealed grain-oriented silicon steel sheet having forsterite oxide coating and in which secondary recrystallization is finished. SOLUTION: The surface of a steel sheet is applied with two layer of a primary layer in which ferrite is coated with forsterite oxide coating or nickel coating, the thickness of the nickel coating is regulated to 0.1 to 1.0μm and the occupying ratio of nickel is regulated to =50wt.%. Furthermore, the steel sheet having forsterite finish-annealed coating is applied with electroless nickel plating, after that, a coating soln. having the above compsn. as the secondary layer is prepd., which is applied thereto, and it is dried and is subjected to baking at 400 to 1,000 deg.C to produce the low core loss grain-oriented silicon steel sheet excellent in corrosion resistance.

Production of fertilizer aqueous solution from electroless nickel plating waste liquid and device

Abstract: PROBLEM TO BE SOLVED: To convert a phosphorus component in a treating liquid into a phosphoric acid fertilizer aqueous solution and utilize an electrolytic Ni plating waste liquid by performing an electrolytic oxidation treatment without diluting the electroless Ni plating waste liquid, as it is. SOLUTION: A production method of a fertilizer aqueous solution from the waste liquid comprises a process for feeding the electroless Ni plating waste liquid to an electrolytic oxidation tank 7 provided with at least a pair of electrodes and vibration agitators 1, 5, 8, 9 for vibrating and stirring the tank inside, and performing electrolytic oxidation, a process for removing harmful metals by treating the waste liquid treated by this process with ion-exchange (an ion exchange body 23) or with an adsorption treatment and a process for neutralizing the treating liquid (a neutralizing tank 25).

Build-up printed wiring board and its manufacturing method

Abstract: PROBLEM TO BE SOLVED: To prevent the surface of an insulation layer from directly contacting a strong alkali plating liquid on electroless copper plating treatment by forming a metal plating film on the roughening surface of the insulation layer by oxidation electroless metal plating treatment. SOLUTION: In a copper-clad lamination plate 10, a copper foil 12 is laminated on both surfaces of an insulation substrate, thus forming a first circuit pattern. An alkali development type photosensitive insulation resin is applied to the inner surface of the copper-clad lamination plate 10 and is dried and cured properly, thus forming an insulation layer 30. Then, after the surface roughening, oxidation electroless nickel plating treatment is performed, thus forming a nickel plating film 50. The thickness of the nickel plating film 50 is determined by considering that the roughening surface of the insulation layer 30 does not directly contact a strong alkali plating liquid on later-process electroless copper plating treatment.

Electrode formation of semiconductor device

Abstract: PROBLEM TO BE SOLVED: To form an electrode of a semiconductor device of uniform and high quality electroless nickel plating by cleaning an exposed semiconductor surface and thereafter immersing it in catalytic water solution wherein pure water of low dissolved oxygen is used as water. SOLUTION: Boron ions are implanted to one surface of a silicon substrate 1 and phosphorus ions are implanted to the other surface, a silicon oxide film is formed by oxidation, a part of a silicon oxide film is removed and etched for forming a mesa groove wherein a p-n junction consisting of a p -type semiconductor region 2 and an n -type semiconductor region 3 is exposed. Then, a silicon oxide film is removed and a glass film 5 is formed. Thereafter, a silicon oxide film formed in a surface of the p -type semiconductor region 2 which becomes an anode layer and the n -type semiconductor region 3 which becomes a cathode layer is removed. After it is immersed in catalytic solution wherein pure water of low dissolved oxygen is used and is subjected to catalyzation treatment, first electroless nickel plating is carried out and an anode electrode 20 and a cathode electrode 30 are formed.

Pretreating liquid for electroless nickel plating and pretreatment

Abstract: PROBLEM TO BE SOLVED: To provide an easier-to-use activator liquid by solving the conventional problem of a narrow management range where the 'bridging' and 'skipping' of the activator liquid hardly arises in a pretreating liquid for electroless nickel plating. SOLUTION: The pretreating liquid for electroless nickel plating is so prepd. as to include chloride ions, palladium (II) ions and substitution accelerator and to assume acidity. One or more kind selected from hypophosphite, phosphite, hydrazine, hydroyxylamine, borane and formalin are used as the substitution accelerator. The acidity is specified to >=0.1N. Further, a compd. which forms a complex with palladium (II) ions, such as an ammonium salt or amines, may be added thereto.

Electroless nickel plating device

Abstract: PROBLEM TO BE SOLVED: To provide an electroless nickel plating device by which a plating soln. and a reducing agent are excellently mixed and consuming only the necessary minimum amt. of liq. without causing an oxygen-rich atmosphere in a system supporting a glass disk in the horizontal direction. SOLUTION: A glass disk 1 on which a rugged pattern is formed in accordance with a recorded signal is electroless-plated by this device to form the metallic master disk for an optical disk. In this case, the glass disk surface is catalytically activated as the pretreatment, and then a plating soln. contg. nickel ion and a reducing agent are sprayed respectively from the gas spray nozzles 6, 7, 70 and 71 and applied on the glass disk. COPYRIGHT: (C)1998,JPO

Preparation of anisotropic conductive fine particles by electroless nickel plating.

Abstract: Demand for mechanical solderless chip connection methods using anisotropic conductive particles has increased in the field of electronic devises. In this study, the preparation of conductive resin particles (5 to 10μm in diameter) by electroless nickel plating and the surface morphology of nickel film were investigated. Since the surface area of particles are much larger than in a bulk substrate, a batch-type electroless plating bath is unstable. Therefore, we applied the continuous dropping method to improve the stability of the Electroless nickel plating. The surface morphology of the deposited nickel was greatly influenced by the complexing agent used, the bath temperatrue and solution pH. Uniform deposits on the particles were obtained at pH 5 by using ammonium acetate as the complexing agent. In contrast, extraneous deposits were recognized at pH 5 when using sodium tartrate as the complexing agent and in baths at pH6. This extraneous deposition could be decreased by lowering the bath temperature.

Activation treating solution for electroless nickel plating, etching solution and production of semiconductor device

Abstract: PROBLEM TO BE SOLVED: To provide an etching soln. and an activation treating soln. of pH11 to 13 improving the adhesiveness of selective electroless nickel plating to aluminum. SOLUTION: This activation treating soln. is obtained by dissolving a palladium compound and a chelating agent contg. ammonium radical in an aq. soln. of an inorganic base in which pH is adjusted. The palladium compound can be selected from among PdCl2 , PdSO4 and Pd(NO3 )2 , the chelating agent can be selected from among NH4 OH, NH4 Cl, (NH4 )2 CO3 and NH4 HCO3 , and the inorganic base can be selected from KOH and NaOH. The etching soln. is obtained by dissolving a palladium compound or zinc compound in an aq. soln. of sulfuric acid. The palladium compound can be selected from among PdCl2 , PdSO4 , Pd(NO3 ) and (NH4 )2 PdCl4 , and the zinc compound an be selected from ZnCl2 and ZnSO4 .

Composite sintered sliding material

Abstract: PROBLEM TO BE SOLVED: To improve the mechanical properties of a material while its slidability caused by a solid lubricant is maintained by composing it of a sintered body composed of copper series base material particles and solid lubricant particles subjected to electroless nickel plating. SOLUTION: As the copper series base material particles, e.g., the ones composed of, by weight, 88 to 92% copper powder and 12 to 8% tin powder can be used. As the solid lubricant particles, e.g., molybdenum disulfide or graphite can be used. As for the electroless nickel plating coating uniformly formed on the surface of the solid lubricant particles, its comps. is composed of about 88 to 97% Ni and about 12 to 3% P. Furthermore, relating to the solid lubricant particles, the weight ratio of the solid lubricant components to the plating coating components is preferably regulated to 1:(0.2 to 1.5). The production of the sliding material is executed by compacting a mixture obtd., e.g. by mixing copper powder, tin powder and the solid lubricant particles and sintering this at a sintering temp. of about 800 to 1100K in a reducing atmosphere. COPYRIGHT: (C)1999,JPO