Showing papers on "Electroless nickel plating published in 2000"

Electroless nickel plating from acid bath

Abstract: The electroless nickel (EN) plating mechanism in acid baths has been proposed. The kinetics of this reaction have been investigated and an empirical rate equation for the baths has been developed. The new aspect of hydroxycarboxylic acid influence in EN plating has been presented.

Method for forming flip chip bump and UBM for high speed copper interconnect chip using electroless plating method

Abstract: A method for forming flip chip bumps or UBM for a high speed copper interconnect chip, and more particularly to a method for forming a flip chip bump or UBM of copper/nickel, copper/nickel/copper or etc. which are carried out by a subsequent process of electroless copper plating and electroless nickel plating on a copper I/O pad. According to the method, both of electroless copper and nickel plating methods are used for forming electroless copper/nickel bumps of a copper interconnect chip so that advantages of the electroless copper plating, i.e. excellent selectivity and adhering strength to the copper chip pad and an advantage of the electroless nickel plating, i.e. excellent plating rate can be achieved at the same time.

Printed circuit board and method for manufacturing same

Abstract: In a multilayer printed circuit board having a conductor pattern, covered with an insulation layer having via holes, these via holes are filled with a conductor by means of electroless nickel plating or electroless copper plating.

Removal and Recovery of Nickel Ion from Wastewater of Electroless Plating by Reduction Crystallization

Abstract: Wastewater treatment after electroless nickel plating runs has been known to be difficult and this has been a subject of worldwide concern. Discarding wastewater of electroless nickel plating into sea was prohibited under the London Dumping Treaty since 1996. We have studied on recovering nickel from wastewater by reduction crystallization. In this study, the characteristics of nickel ion removal and recovery were investigated in the process of reduction crystallization using a laboratory scale batch crystallizer (500 ml), in order to propose a new process for wastewater treatment from nickel plating. In the reduction crystallization, which can use hypophosphite ion as a reducing agent for nickel ion in the wastewater, nickel ion could be recovered as a form of nickel metal by seeding nickel powder having large specific surface area.

Electroless Nickel Plating for Nanofabrication in Optics

Abstract: The electroless plating method has played an important role as an indispensable metallization technology for miniaturization of electronic components. This investigation discusses selective metallization on the fine area (nanometer size) by electroless plating. The experimental purpose is to fabricate a probe which is used for scanning near‐field optical microscopy. The probe (cone angle 20°, probe size 4 μm) is comprised of an optical fiber covered with a metal film except for an aperture at the apex of the fiber. Nickel‐plated probes with an aperture of 100 nm were fabricated by optimization of the plating conditions (dissolved oxygen concentration, bath temperature, and bath pH) and the addition of a catalytic poison into the plating bath. © 2000 The Electrochemical Society. All rights reserved.

Assessment on the effects of electroless nickel plating on the reliability of solder ball attachment to the bond pads of PBGA substrate

Abstract: This paper presents an experimental study to assess the reliability of solder ball attachment to the bond pads of PBGA substrate with various plating schemes. The basic structure of under bump metallization is Cu/Ni/Au. Three different kinds of electroless plating solutions are used to deposit the Ni layer, namely, Ni-B, Ni-P (5%), and Ni-P (10%). Also, the conventional electrolytic Ni/Au plating is performed for benchmarking. After solder ball attachment, mechanical tests are conducted to characterize the ball shear strength for comparison. Furthermore, some specimens are subjected to multiple reflows to investigate the thermal aging effect. The testing results reveal that, compared to the electroless Ni-P plating, the electroless Ni-B plating may lead to better solder ball shear strength. However, the conventional electrolytic plating still gives the highest ball shear strength. For most cases under investigation, multiple reflows seem to slightly reduce the solder ball shear strength. In addition to the ball shear tests, scanning electron microscopy is performed to inspect the cross-section and the fracture surface of the tested specimens. From the failure analysis, certain characteristics are identified for various Ni plating schemes.

Diffusion bonding of a superplastic Inconel 718SPF superalloy by electroless nickel plating

Abstract: Although intimate contact can be obtained for diffusion bonding of a superplastic Inconel 718SPF superalloy under a low pressure of 7 MPa, the precipitates formed at the interface retarded achievement of a sound joint. The shear strength was only 41.5 MPa for an overlap length of 12 T (T=1.3 mm, sheet thickness). The diffusion bondability of this Inconel 718SPF superalloy was enhanced by electroless nickel plating. In this situation, the bonding shear strength increased to 70.4 MPa for the same overlap length of 12 T under the same bonding condition, regardless of the roughness of the surface to be bonded. Upon decreasing the overlap length from 12 to 6 T, the bonding strength remained constant.

Electroless nickel plating liquid

Abstract: PROBLEM TO BE SOLVED: To provide an electroless nickel plating liquid which suppresses the production of deposits to be a cause for changing the properties of the plating liquid after being prepared, during storage or during plating operation, maintains excellent liquid stability for a long time and has excellent corrosion resistance and wettability of solder of nickel plating films. SOLUTION: This electroless nickel plating liquid contains metal elements having >=2 kinds of valence at a pH 3 to 8.

Electrochemical Measurements of Electroless Nickel Coatings on Zincated Aluminium Substrates

Abstract: SUMMARYZincate pre-treatment of aluminium substrates and the effects of deposit thickness on the corrosion resistance of electroless nickel deposits on aluminium have been studied by electrochemical methods. The results show the importance of the controlled zincate pre-treatment step on the induction period for electroless nickel plating. The protective properties of the nickel deposit are evaluated, as a function of thickness, using linear polarisation resistance and zero resistance ammetry techniques. The corrosion resistance of the deposits, which is strongly related to their thickness, is compared to the results of porosity testing on steel substrates. An essentially non-porous deposit is obtained after a thickness of 5–10 microns has been deposited on aluminium substrates under the experimental conditions.

Method for plating micro-waveguide with silver

Abstract: PURPOSE: A method for plating silver on a micro-waveguide is provided to produce a micro-waveguide available to prevent loss of high frequency. CONSTITUTION: An acid electroless nickel plating having nonmagnetic property is performed to obtain excellent adherence with an aluminum alloy and corrosion resistance 5 times stronger than an electric nickel. An acid solution for the electroless nickel plating is composed of 4.0-8.0g/l of sulfate of nickel, 20-50g/l of sodium hypophosphoric acid as a complexing agent and caustic soda as pH regulating agent. If electric conductivity of the electroless nickel-plated layer is not sufficient in a high frequency band, an electric copper plating is performed in the thickness of 3-10 micrometers. The electric copper plating is performed by using an alkali cyanide copper plating solution or an acid sulfate copper plating solution as an electric copper plating solution. After the plating process, silver plating is performed.

Electroless Nickel Plating Using Hydrazine Reducing Agent with Excellent Bath Stability

Abstract: An electroless nickel plating bath with a hydrazine reducing agent has been investigated. An electroless nickel plating bath with a deposition rate of about 3μm/hr and superior bath stability as compared to previously reported bath has been developed. The new bath is a simple system consisting of glycine and boric acid in addition to nickel and hydrazine. The optimum plating conditions for the bath are in the range of 85-90°C at a pH of 12. The deposits obtained from the developed bath are black with a surface morphology that has a dendrite structure. Characteristics of deposits such as specific resistance and solderability were superior to those of conventional nickel-phosphorus deposits. Results confirmed that nickel was directly deposited on a copper substrate from an electroless nickel plating bath with a hydrazine reducing agent without an activation step in pretreatment.

Manufacture of rp tools with high quality surface finish using high temperature epoxy resin and electroless nickel plating

Abstract: Rapid tooling is gaining increasing attention in the manufacturing sector, especially for the development of new products, owing to its distinctive characteristics. Rapid prototyping techniques can be used in this prospective manufacturing area to produce tooling either directly or indirectly. Although powder metal based rapid prototyping systems are considered most effective for rapid tooling, the requirements for injection moulding are not yet fully attained. In the present study, rapid tooling produced by direct laser sintering of metal powder has been investigated with the aim of improving its quality for industrial acceptance. High temperature epoxy resin was used to fill the pores to improve compressive strength, and electroless nickel plating was employed to enhance hardness, conductivity, ductility, lubricity, wear, and abrasion resistance without affecting dimensional accuracy. Results demonstrate that these techniques possess significant potential for rapid tool production.

Production of etching parts

Abstract: PROBLEM TO BE SOLVED: To provide process for producing etching parts (seal gaps, etc.), which are not formed with metal plating layers in half-etched regions. SOLUTION: The metal plating layer 12 and metal plating layer 13 of 0.5 to 2.0 μm in film thickness are formed by electroless nickel plating on both surfaces of a metallic base material 11 and a photoresist is applied thereon to form a photosensitive layer 14 and photosensitive layer 15 on the metal plating layer 12 and metal plating layer 13. Next, the photosensitive layer 14 on one surface is subjected to a patterning treatment to form resist patterns 14a. The metal plating layer 12 and metallic base material 11 are partly etched with the resist patterns 14a as a mask by which metal plating pattern layers 12a and apertures 16 are formed. Next, the resist patterns 14a and the photosensitive layer 15 are subjected to a peeling treatment and the prescribed positions of the apertures 16 are blanked, by which the etching parts 10 having the half- etched regions free of the metal plating layers at both ends of the metallic base material 11 are obtained.

Electroless plating method and apparatus therefor

Abstract: PROBLEM TO BE SOLVED: To lessen the occurrence of defects, such as pits, pinholes and gritty feel, without the stagnation of gaseous hydrogen generated at the time of a plating reaction by downwardly facing the effective plating surface of an object to be plated in a plating bath and rotating or revolving the object to be plated. SOLUTION: The object 7 to be plated which is mounted at a fixing shaft 4 is successively subjected to pretreatments including pickling, zinc replacement, dilute nitric acid immersion and zinc replacement. An angle adjusting device 6 is then so regulated that the fixing shaft 4 holding the object 7 to be plated in a prepared electroless nickel plating liquid 8 attains an angle of about 30 deg.. The object 7 to be plated is rotated at a number of revolutions of 1 rpm by a speed variable motor 2 and the gaseous hydrogen generated at the time of the plating reaction is allowed to escape to the outer side of the plating surface without stagnating the gaseous hydrogen at one point by the relation between the curvature of the plating surface and the angle of inclination and the rotation. The object 7 to be plated is revolved by adjusting the number of revolutions of the speed variable motor 2 to about 5 rpm.

Electroless plating method for glass ceramic substrate

Abstract: PROBLEM TO BE SOLVED: To provide an electroless plating method for a glass ceramic substrate by which the adhesion between the glass ceramic substrate as a base body and a conductor pattern is satisfactory even in the case electroless plating of nickel-gold is executed to the glass ceramic substrate in which the conductor pattern had been formed. SOLUTION: When forming a nickel layer-gold layer on a conductor pattern on a glass ceramic substrate by electroless plating, a degreasing cleaning stage using an acid treating soln., an etching stage suing an acid etching soln., an acid activating stage using an acid activating soln. and a palladium treating stage using acid and neutral treating solns. are executed in this order, and, after that, to the surface of the conductor pattern, an electroless nickel plating stage in a neutral bath and an electroless gold plating stage in an acid bath or a neutral bath are executed in this order.

Method of forming nickel film by electroless nickel plating

Abstract: PROBLEM TO BE SOLVED: To provide a method of easily forming a plating film of a low cost having high adhesion without using costly palladium by an electroless nickel plating to metal, such as Bi, which is to be a catalyst poison. SOLUTION: This method of forming nickel film on the surface of a metallic material which is to be a catalyst poison by the electroless nickel plating, comprises using a plating bath having a boron compound as a reducing agent together with a nickel salt of an inorganic acid or organic acid in formation of the metallic film by the electroless nickel plating to the surface of the metallic material which is the catalyst poison, immersing the material to be plated into this plating bath and bringing the metal catalytically active to the reducing agent into contact with the material to be plated in this plating at the start of the plating to effect galvanic initiation. As the boron compound, diimethylamino boron is most preferable.

Metallic microstructures by electroplating on polymers : an alternative to LIGA technique

Abstract: In this paper, a new technique of obtaining nickel electroplated layers on polymethylmethacrylate (PMMA) is presented. It consists of four steps. 1. Conditioning . Strongly oxidizing acid mixtures are used for providing roughness on the surface by generating suitable sites for chemical bonding of subsequently applied metals. 2. Nucleation . Using an acidic solution of a mixture of a palladium salt together with a tin salt it can be obtained an adsorbed film on PMMA’s surface that is reduced to metallic form. 3. Electroless nickel plating . This step transforms PMMA into a conductive surface and builds up metal only to provide sufficient conductivity for electroplating. This is achieved in a classical hypophosphite electroless nickel solution. 4. Nickel electroplating . Metallic microstructures are finally obtained by growing up, at the desired thickness, nickel layers on the thin electroless ones, using a standard sulphamate bath for rapid electroforming. This method of obtaining nickel electroplated microstructures was developed to replace the classical Lithographie, Galvanoformung, Abformung (LIGA) technique (mainly to avoid the use of the costly synchrotron system).

Derivation and rapid spectrophotometric determination of iron in electroless nickel plating solution

Abstract: Experiment has proved that iron can be dissolved in an acidic electroless nickel (EN) plating solution during the plating process when plating iron sheet. The influence of nickel sulfate, organic acids, sodium hypophosphite, pH and temperature on the absorption of Fe(III) was investigated. A new method, using mono-wavelength, to determine the concentration of Fe(III) was developed. Fe(II) was oxidized to Fe(III) to determine the total iron in the range 0.02 to 19.42 mg/L with recovery of more than 96.6 percent. Results confirmed that this method is easy, uses simple instruments, is quick and offers high accuracy in the process of measurement. This method can be applied to rapid determination of total iron in EN solutions, as well as determining whether the substrate is completely covered by Ni-P alloy if iron sheets are used.

Method for treating aged electroless nickel plating solution

Abstract: PROBLEM TO BE SOLVED: To provide a treatment method capable of efficiently separating and removing Ni ions, a phosphite component and organic acids by a simple operation from an aged electroless Ni plating solution. SOLUTION: This treatment method comprises a process 1 in which Ni ions in an aged solution are separated and recovered as Ni metal through an electroless plating reaction caused by bringing an aged electroless Ni plating solution into contact with Ni powder, a process 2 in which the separated host solution in the process 1 is brought into contact with a chelate resin to absorb and separate residual Ni ions, a process 3 in which a dissolved phosphite component is separated and recovered as Ca phosphite by reacting gypsum or mineral acid and hydrated lime with the separated solution in the process 2, a process 4 in which the residual phosphite component is oxidized and decomposed in the presence of an oxidant into a phosphoric acid component and separated and recovered as Ca phosphate by a reaction with a Ca salt, and a process 5 in which organic substances in the separated solution in the process 4 are removed by an activated sludge process.

Manufacture of schottky barrier diode

Abstract: PROBLEM TO BE SOLVED: To obtain a Schottky barrier diode capable of solder connection by forming a barrier electrode constituting a Schottky barrier diode by using electroless nickel plating. SOLUTION: This diode consists of a first conductivity type semiconductor layer 1, a barrier electrode 21 which is formed on the main surface of the semiconductor layer 1 by nickel plating, and a second conductivity type semiconductor region 2 which is formed around the barrier electrode 21 and in ohmic contact with it. The barrier electrode formed by nickel plating is connected with an outer terminal via a solder layer 25, and a Schottky barrier diode is manufactured. In this manufacturing method, the barrier electrode 21 is formed by electroless plating in which dimethylamine borane is used as reducing agent.

Method for regenerating electroless nickel plating solution

Abstract: PROBLEM TO BE SOLVED: To separate phosphite produced and accumulated in an electroless nickel plating solution exhaused in by plating operation as calcium phosphite therefrom and to reuse the same as a plating solution. SOLUTION: For regenerating a plating solution having a fundamental composition obtained by combining nickel hydroxide, nickel carbonate or nickel hypophosphite to form into a nickel source and hypophosphorous acid, nickel hypophosphite or sodium hypophosphite to form into a reducing agent, a calcium carbonate or calcium hydroxide is added to the plating solution. In this way, phosphite produced and accumulated in the plating solution by the oxidation of hypophosphite is precipitated and formed as calcium phosphite. At this time, the amount of calcium carbonate or calcium hydroxide to be added is controlled so that the pH of the solution upon the end of the reaction reaches 4.5 to 5.8, and moreover, hypophosphorous acid is added. The precipitated and formed calcium phosphite is separated, and the recovered mother liquor can be reutilized as a plating solution.

Use of iron(III) hydroxide as an adsorbent for the removal of chromium(VI) from industrial waste water

Abstract: Weakly crystallized α-form of iron(III) hydroxide was synthesized. Its structure-related (the specific surface area, the dominant pore radius, and the total pore volume) and adsorption (the dynamic exchange capacity with respect to chromium(VI)) characteristics were determined. Experiments aimed at the selection of modifying additives increasing the mechanical strength of iron(III) hydroxide were carried out. It was shown that adsorbents modified simultaneously with nickel(II), cobalt(II), zinc, and aluminum have a mechanical strength enough for their use in industrial adsorption units. An economical method was developed for the synthesis of mechanically strong iron(III) hydroxide-based adsorbent for removing chromium(VI) from industrial waste water. The adsorbent can be synthesized from spent solutions used for printed-circuit boards or steel etching or for electroless nickel plating.

Maskless Metal Patterning on Polyimide Substrate Using Laser-Enhanced Electroless Nickel Plating.

Abstract: We studied how polyimide substrate etching and argon laser irradiation conditions affected the deposition of nickel line patterns. Polyimide substrates were etched in NaOH solutions at room temperature, followed by measurement of contact angles, AFM diagrams, and FT-IR spectra to determine optimum NaOH concentration and etching duration ensuring good deposition. After etching at concentrations exceeding 10 wt% and at durations exceeding 30 s, the etched substrate surface consisted of polar molecules and had a low contact angle, resulting in good nickel pattern deposition. Excess etching caused macroscopic roughening of the substrate surface. Although a certain degree of laser power density was needed to ensure deposition, too high a power caused plating solution to boil and substrates to be thermally damaged. When laser beam was scanned at more than 50 ƒÊm/s, no deposition was obtained because substrates were not heated enough. Optimum deposition was at 300-800 W/cm2 and scanning slower than 25 ƒÊm/s for a substrate 50 ƒÊm thick and a beam diameter of 100 ƒÊm. Nickel lines about 100 pm wide and 0.3-0.4ƒÊm thick were obtained, although their width increased with increasing power density.

Molding die and manufacture of optical element

Abstract: PROBLEM TO BE SOLVED: To provide a molding die which does not form wrinkles even when a mumber of dents are formed. SOLUTION: Since this molding die comprises a die base metal 4 having a mumber of pores and an electroless nickel plating layer 5 coating the surface to be molded, when a dent for element 3b is to be formed, the electroless nickel plating layer 5 is deformed in accordance with the surface shape of an indenter on a cavity surface 3a, and the die base metal 4 is also recessed while reducing the volume of the pores in accordance with the surface shape of the indenter. In other words, since the volume change due to the deformation in a process of dents is absorbed in the pores of the die base metal 4, wrinkles are hardly formed around the dents for element 3b, so that the wrinkles can be prevented from being formed on the surface of an array of microoptical element to be molded by the resultant molding die.

Manufacturing method of liquid bearing components, motor provided with fluid bearing components, and disk drive using the same

Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method that enables manufacturing a fluid bearing components in which no excessive wear results after long period of operation and offering an excellent productivity. SOLUTION: After forming a metal layer composed of metallic material having a hardness higher than that of copper over the surface of base material of which chief constituent is the copper, dynamic pressure grooves are built on the metal layer by an electrochemical machining. In view of the hardness of the metal layer and the electrochemical machinability, a metal layer had better be a nickel as a main constituent. A metal layer also had better be formed by a plating, because of an uniform metal layer obtained. In order to improve further the abrasion resistance property by increasing the hardness of the metal layer, it is better that an annealing treatment is applied after the metal layer is formed by an electroless nickel plating. The layer thickness of the metal layer is preferable to be in the range of 5-30 μm, due to a tradeoff between the depth of dynamic pressure grooves and the uniformity of the layer thickness of the formed metal layer. COPYRIGHT: (C)2001,JPO

Corrosion-proof structure of water injection compressor piping

Abstract: PROBLEM TO BE SOLVED: To reduce costs, prevent corrosion, and improve durability by forming piping for a water circulation circuit with aluminum alloy, forming a connecting member of the piping with a cupper alloy material, and covering its outer surface with a metallic material having small corrosion potential difference with respect to the aluminum alloy. SOLUTION: A receiver tank 5 is formed with special alloy serving aluminum as a main body and having strength withstarding the pressure of compressed air. A heat exchanger 11 is also formed with aluminum alloy having a high thermal conduction ratio. Each piping connected to each apparatus, namely, a delivery pipe 4, a water piping 12, a cooling piping 14, and the like are simultaneously formed with aluminum alloy. In a piping coupler as a connecting part of the piping, namely, in a joint, a sleeve and a sleeve nut, an easily passivated metallic surface treating material such as nickel chrome plating, electroless nickel plating, or the like is applied to a surface of a base material made of cupper alloy, and the whole of the base material is covered.

Catalytic activity of sputtered palladium films for electroless nickel plating studied using a quartz crystal microbalance

Abstract: The catalytic activity of palladium films sputtered on a quartz resonator was studied using a nickel bath in which a quartz crystal microbalance was used to determine electroless plating processes. An adhesive interface between the Pd layer and the quartz surface influenced activity. A chromium underlayer suppressed the catalytic activity of Pd film, but a gold underlayer did not. A palladium layer formed on Au a layer operated as a catalyst. The catalytic activity of Pd film on the Cr underlayer was greatly enhanced by cathodic treatment in dilute hydrochloric acid.