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Showing papers on "Electroless nickel plating published in 1984"


Patent
08 Aug 1984
TL;DR: In this paper, a process for improving the electroless nickel plating of aluminum which has been pretreated with a barrier coating such as zinc by employing multiple plating baths under controlled operating conditions is provided.
Abstract: A process is provided for improving the electroless nickel plating of aluminum which has been pretreated with a barrier coating such as zinc by employing multiple plating baths under controlled operating conditions.

44 citations


Patent
05 Mar 1984
TL;DR: In this paper, an improved aqueous electroless nickel plating bath and process for chemically depositing nickel on a substrate were described. But they did not consider the effect of supplemental organic and/or inorganic rate stabilizers.
Abstract: An improved aqueous electroless nickel plating bath and process for chemically depositing nickel on a substrate comprising an aqueous solution containing nickel ions, hypophosphite ions, a complexing agent, preferably a buffering agent and a wetting agent, and a small but effective amount of a sulfonium betaine compound sufficient to control the rate of nickel deposition and the concentration of phosphorus in the nickel deposit, preferably, in further combination with supplemental organic and/or inorganic rate stabilizers. The invention further contemplates a process for rejuvenating an electroless nickel bath which has been rendered inoperative due to the presence of excessive concentrations of supplemental stabilizing agents by the addition of a controlled effective amount of a sulfonium betaine compound sufficient to restore the bath to an operative plating condition.

33 citations


Journal ArticleDOI
TL;DR: In this article, the catalytic activity of copper, palladium-activated copper, gold, and platinum for electrooxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to 0.92V vs SCE.
Abstract: The catalytic activity of copper, palladium-activated copper, gold, and platinum for electro-oxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to -0.92V vs. SCE. Early stages of nickel plating on copper-palladium substrates were studied by scanning electron microscopy in conjunction with EDAX. It was found that palladium-activated copper and gold were catalytically active in the entire range of potentials examined; copper was active below -0.6 platinum was not active at all. Small amounts of electrolytically deposited nickel considerably increased the electro-oxidation rate of hypophosphite on copper, gold, and palladium. TEM examinations showed that activation of copper in a PdCl/sub 2//HCl solution resulted in the deposition of palladium in the form of separate patches. Electroless nickel deposition on copper substrates with separate palladium spots took place on copper and palladium independently of each other. The deposition on palladium was faster than that on copper. It was concluded that the activation of copper substrates around palladium spots occurred solely through a spontaneous potential shift, induced by electro-oxidation of hypophosphite on the palladium spots. It was suggested that small amounts of one metal synergisticallymore » enhanced the catalytic activity of the other metals.« less

26 citations


Journal ArticleDOI
TL;DR: In this paper, the catalytic activity for electrooxidation of hypophosphite and electroless nickel plating on iron, nickel, and electrolessly plated nickel was investigated in an ammoniacal solution of pH 8.8 at 50°C by potential measurements and linear sweep voltammetry from −0.3V to 0.92V vs. SCE.
Abstract: The catalytic activity for electrooxidation of hypophosphite and electroless nickel plating on iron, nickel, and electrolessly plated nickel (with 2.2–2.9 weight percent (w/o) P) was investigated in an ammoniacal solution of pH 8.8 at 50°C by potential measurements and linear sweep voltammetry from −0.3V to 0.92V vs. SCE. Cathodic polarization of any of the substrates (in ) before testing or permeation of hydrogen through iron foils during testing reduced the incubation time for electroless plating, increased anodic dissolution of the substrates in the passive region, and increased the hypophosphite electrooxidation on nickel and nickel‐phosphorus at potentials of thermodynamic stability for nickel oxides or hydroxides. The nickel‐phosphorus substrate exhibited significantly higher activity than pure nickel, in a similar manner to the effect of cathodic polarization. The effect of cathodic polarization and hydrogen is associated with the electrochemical reduction of surface oxides, whereas the higher activity of nickel‐phosphorus deposits (as compared to that of pure nickel) is explained by the lower protectivity of surface oxides on these deposits.

24 citations


Patent
02 Apr 1984
TL;DR: In this article, an inner glass tube 7 is dipped in a sensitiveness imparting solution for about three minutes, and after cleaning it in water, it was dipped in an activation treating solution at about 40 degC for about thirty seconds Next, it is electroless plated in an electroless nickel plating solution selected from nickel, silver, copper, and cobalt after drying it, a film is formed on it by coating a blended solution of titanium dioxide, tantalum pentoxide, and niobium pentoxide.
Abstract: PURPOSE:To improve heat-resistant properties and reproducibility in a solar heat collector, by forming a metallic layer consisting of selective heat absorption layer on the collector by a method of electroless plating of nickel or the like, and by forming a dielectric film on the metallic layer by coating a solution of such as titanium dioxide on it, and then by treating it in an oxidizing atmosphere CONSTITUTION:An inner glass tube 7 is dipped in a sensitiveness imparting solution for about three minutes, and after cleaning it in water, it is dipped in an activation treating solution at about 40 degC for about thirty seconds Next, it is electroless plated in an electroless nickel plating solution selected from nickel, silver, copper and cobalt After drying it, a film is formed on it by coating a blended solution selected from titanium dioxide, tantalum pentoxide, and niobium pentoxide Then it is heat-treated in an oxidizing atmosphere at the temperature higher than 500 degC to form a selective heat absorption film 6 on the outer surface of a glass bute 7 The glass tube 7 is inserted into an outer glass tube 3, and a parabolic plate mirror 2 is fitted to the glass tube 3 With such an arrangement, heaat-resistant properties and reproducibility can be improved in a solar heat collector

11 citations


Patent
05 Sep 1984
TL;DR: In this paper, a plated plastic material was obtained by supporting noble metallic ions on a plastic material with a surface treating agent having noble metal capturing action and by forming a metallic film having high bonding strength by electroless plating.
Abstract: PURPOSE:To obtain a plated plastic material by supporting noble metallic ions on a plastic material with a surface treating agent having noble metal capturing action and by forming a metallic film having high bonding strength by electroless plating. CONSTITUTION:Phenol resin powder is well mixed with an aminosilane com pound such as gamma-aminopropyltriethoxysilane as a surface treating agent having noble metal capturing action and an aqueous PdCl soln., and the mixture is dried and held at about 110 deg.C to support Pd ions on the surface of the powder. This powder is put in an electroless plating, soln., preferably an electroless nickel plating soln., and plating is carried out under stirring to obtain nickel plated powder. By this method a plated material suitable for use as a resin additive for providing electric conductivity is obtd.

10 citations


Journal ArticleDOI
TL;DR: In this article, the catalytic activity of copper, palladium-activated copper, gold, and platinum for electrooxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to 0.92V vs SCE.
Abstract: The catalytic activity of copper, palladium-activated copper, gold, and platinum for electro-oxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to -0.92V vs. SCE. Early stages of nickel plating on copper-palladium substrates were studied by scanning electron microscopy in conjunction with EDAX. It was found that palladium-activated copper and gold were catalytically active in the entire range of potentials examined; copper was active below -0.6 platinum was not active at all. Small amounts of electrolytically deposited nickel considerably increased the electro-oxidation rate of hypophosphite on copper, gold, and palladium. TEM examinations showed that activation of copper in a PdCl/sub 2//HCl solution resulted in the deposition of palladium in the form of separate patches. Electroless nickel deposition on copper substrates with separate palladium spots took place on copper and palladium independently of each other. The deposition on palladium was faster than that on copper. It was concluded that the activation of copper substrates around palladium spots occurred solely through a spontaneous potential shift, induced by electro-oxidation of hypophosphite on the palladium spots. It was suggested that small amounts of one metal synergisticallymore » enhanced the catalytic activity of the other metals.« less

4 citations


Patent
19 Dec 1984
TL;DR: In this article, a titled plating soln is provided by adding a rhodanine compd. to a soln. This compd is used to prevent decomposition and adjust pH.
Abstract: PURPOSE:To provide a titled plating soln. which has good throwing power and permits plating at a low temp. by adding a rhodanine compd. to a soln. prepd. by contg. Ni ion complexed by pyrophosphate, glycolate, etc. and a boron hydride compd. and adjusting the pH thereof. CONSTITUTION:Ni sulfate is used as a soluble Ni salt and a complexing agent as much as Ni ion can be thoroughly completely complexed or more than said amt. is used. Pyrophosphate, glycolate, malate and citrate are used as the complexing agent. A boron hydride compd. [NaBH4, (CH3)2NHBH3, KBH4] is added as the reducing agent to the soln. and the soln. is made alkaline by NH4OH, KOH, NaOH, etc. for the purpose of preventing decomposition and adjusting pH. A slight amt. of rhodanine or the deriv. of rhodanine, for example, p-dimethyl aminobenzylidene rhodanine is added to such soln. by which a plating soln. having a long soln. life is obtd. If such soln. is used, plating is accomplished at a relatively low temp. on the inside wall of a pipe having about 0.5mm. inside diameter and on plastics as well.

3 citations


Patent
27 Dec 1984
TL;DR: In this paper, TeO2 is added as a brightener to an electroless nickel plating soln to such a degree that it is present in a supersatd state.
Abstract: PURPOSE:To form bright adhesive plating of a uniform thickness on an article of a complex shape, a plastic article or the like by using TeO2 as a brightener. CONSTITUTION:TeO2 is added as a brightener to an electroless nickel plating soln. to such a degree that it is present in a supersatd. state. Since TeO2 is almost insoluble in the plating soln., it is practically added by about several ppm/l.

3 citations


Patent
22 Dec 1984
TL;DR: In this paper, a machined light alloy casting is precision-machined to a prescribed size and is then washed with an org. solvent so that the cutting oil is removed as much as possible.
Abstract: PURPOSE:To prevent generation of dust from the surface of a machined light alloy casting by subjecting said casting to electroless nickel plating then subjecting the remaining cutting oil to a carbonization treatment. CONSTITUTION:A light alloy casting is precision-machined to a prescribed size and is then washed with an org. solvent so that the cutting oil is removed as much as possible. The casting is thereafter subjected to alkali washing to remove the dust failing to be removed and to washing. The casting surface is further etched to remove the deteriorated surface layer of the release agent and oxide film and the etched casting is washed. The surface is subjected to zinc replacement to form about 0.2-0.3mu zinc layer and is washed. Electroless nickel is plated about >=3mu thereon by electroless nickel plating to prevent the dislodging of the fine casting metal pieces and thereafter the casting is washed. A chromic acid soln. having a prescribed concn. is adjusted in pH and is heated to prepare a treating soln. in which the casting is dipped to dissolve and remove the cutting fluid in the blowholes failing to be removed by a carburization treatment. After the casting is washed, an ultrasonic wave is used in combination in hot water to remove thoroughly the chromic acid.

2 citations


Patent
08 Jun 1984
TL;DR: In this article, a process for rejuvenating an electroless nickel bath which has been rendered inoperative due to the presence of excessive concentrations of supplemental stabilizing agents by the addition of a controlled effective amount of the sulphonium betaine compound sufficient to restore the bath to an operative plating condition is described.
Abstract: An aqueous electroless nickel plating bath comprises nickel ions, hypophosphite ions, a complexing agent, preferably a buffering agent and a wetting agent, and a small but effective amount of one or more sulphonium betaine compounds sufficient to control the rate of nickel deposition and the concentration of phosphorus in the nickel deposit. The or each sulphonium betaine compound has the structure: wherein: R1, R2, R3 and R4 are the same or different and each represents H, a C1-C6 alkyl radical or a C1-C6 hydroxy alkyl radical, R represents H or OH, and n is an integer of from 1 to 5. Preferably, supplemental organic and/or inorganic rate stabilizers are also present. A process for rejuvenating an electroless nickel bath which has been rendered inoperative due to the presence of excessive concentrations of supplemental stabilizing agents by the addition of a controlled effective amount of the sulphonium betaine compound sufficient to restore the bath to an operative plating condition.

Journal ArticleDOI
TL;DR: An experimental investigation was made of the effects of optical radiation on the autocatalytic process of electroless nickel plating at an interface betweeen a solid and a liquid as discussed by the authors.
Abstract: An experimental investigation was made of the effects of optical radiation on the autocatalytic process of electroless nickel plating at an interface betweeen a solid and a liquid. Local optical heating gave rise to special features in the reaction. The rate of reduction of the metal was 20?30 times higher than in traditional methods and there was also some ordering of the structure of the deposit.

Patent
02 Apr 1984
TL;DR: In this article, a stem substrate for a power transistor sealed airtightly with lead wires and a heat sink 7 is subjected externally to electroless nickel plating in a soln.
Abstract: PURPOSE:To improve wettability with solder by dipping the soldering parts such as a stem for a power transistor or the like which are subjected externally to electroless nickel plating in a soln. of sodium hypochlorite under specific conditions and rinsing and drying the same. CONSTITUTION:A stem substrate 1 for a power transistor sealed airtightly with lead wires 6 and a heat sink 7 is subjected externally to electroless nickel plating. Soldering of an element such as a transistor pellet or the like to the heat sink 7 is accomplished by dipping the substrate 1 for 3-10min in a soln. of 5-25% sodium hypochlorite heated to 80-90 deg.C then rising and drying the same. The oxidized film on the surface of the plating layer is thus reduced off and the active surface is exposed, whereby the wettability with solder is improved.

Patent
26 Sep 1984
TL;DR: In this paper, the primary metallic film is used to prevent heat from dispersing from a copper pipe to the uppermost surface film and is highly adhesive to copper material, upon which the secondary metallic film 13, which is highly resistant to corrosion to combustion condensate, is overlapped.
Abstract: PURPOSE:To maintain the resistance to corrosion for a long time, by plating a metallic film, having highly adhesive properties to copper, on the surface of copper pipe of a heat exchanger for a tap-controlled gas water heater and the like, and by plating further a metallic film, having high resistance to corrosion to combustion condensate, on the surface of the primary plated surface. CONSTITUTION:The primary metallic film 12, which is to be a prevention for heat from dispersing from a copper pipe to the uppermost surface film and is highly adhesive to copper material, is plated on the surface of a copper pipe 11, upon which the secondary metallic film 13, which is highly resistant to corrosion to combustion condensate, is overlappingly plated. The metallic film 12 is a barrier metallic film, for example, and electroless nickel plating is used for it. For the metallic film 13, tin plating is used, for example. With such an arrangement, the intermediate layer film 12 can prevent the outermost layer film 13 from deteriorating caused by thermal dispersion from the copper pipe 11, so that the resistance to corrosion can be maintained for a long time.

Patent
03 Dec 1984
TL;DR: In this paper, the authors proposed a method to produce a molded article, suitable for boxes of electronic equipment, and having stable electromagnetic wave shielding effect at a low cost by easy operation.
Abstract: PURPOSE:To produce a molded article, suitable for boxes of electronic equipment, and having stable electromagnetic wave shielding effect at a low cost by easy operation, by pretreating continuously a film or sheet of a resin composition, molding the pretreated film or sheet under differential pressure, and covering the molded film or sheet with a plating film. CONSTITUTION:A film or sheet of a resin composition containing an ABS resin e.g. acrylonitrile-butadiene-styrene copolymer or mixed resin thereof with a copolymer consisting essentially of acrylonitrile and alpha-methylstyrene, etc. and/or an MBS resin, e.g. methyl methacrylate-butadiene-styrene copolymeric resin, and a polycarbonate resin is continuously pretreated and molded by the differential pressure molding method, and the surface thereof is then covered with an electroless nickel plating film, preferably consisting of two layers of an Ni-P electroless plating film and Ni-P-Co electroless plating film.

Patent
14 Nov 1984
TL;DR: In this article, a thin sheet core of a ''Sendust'' alloy composed of 6.2wt% Al, 9.6wt% Si, and 84.2t% Fe is presented.
Abstract: PURPOSE:To improve reproducibility and mass-productivity by coating an alloy thin sheet core provided with a magnetic gap and a closed magnetic path with a nonmagnetic metallic plating film. CONSTITUTION:15 denotes a thin sheet core of a ''Sendust'' alloy composed of 6.2wt% Al, 9.6wt% Si, and 84.2wt% Fe. The core 15 is beforehand deposited with an SiO2 film 6'' of about 0.2-0.3mum by a sputtering method, etc. on the magnetic gap 6' between the upper corner parts 4', 5' which are brazed to face each other for the need of facilitating the plating operation by adhering securely core blocks 2' and 3' in the case of butting said core blocks. An Ni-P alloy film 16 as a nonmagnetic metallic plating film is formed by immersing the core 15 in an electroless nickel plating soln. to be subjected to hypophosphite reduction to coat the plating film over the entire surface thereof then polishing the end face covering the gap 6' until the gap 6' is exposed. Since the alloy core is coated and reinforced by the nonmagnetic metallic plating film in the above- mentioned way, the coating is easily accomplished without requiring another reinforcing member and without requiring the stage for sandwiching and assembling the core.