Showing papers on "Electroplating published in 1974"

Predetermined thickness profiles through electroplating

Abstract: A metal film having a predetermined thickness profile is obtained on a surface of an article through electroplating. The electroplating of the metal film on the article is done with an apparatus including a plurality of modifying electrodes and a body of plating material suspended in a plating solution. Electrical potentials are established at the article to be plated, the body of plating material, and at each one of the modifying electrodes. The particular electrical potential at the article, the body of plating material and at each one of the modifying electrodes is chosen to provide differences in electrical potential which result in a metal film having the predetermined thickness profile.

Trivalent chromium electroplating baths and electroplating therefrom

Abstract: It is known to attempt to plate chromium from a solution containing trivalent chromium salts and organic complexants. The invention provides an aqueous chromium electroplating system containing trivalent chromium, together with both a formate or acetate and a bromide. Optionally the solution also contains ammonium, borate, chloride, sulphate and alkali metal ions and a wetting agent. The invention has the advantage of providing a solution with commercially acceptable covering and throwing power whose effluent can easily be purified to acceptable standards.

Pretreatment of plastic materials for metal plating

Abstract: Plastics and articles made therefrom are metal plated by conditioning their surface by a treatment with sulfur trioxide vapor or a sulfur trioxide containing atmosphere. The thus conditioned plastics or plastic articles are then metal plated, if required, after sensibilization, nucleation or activation, and treatment with a reducing solution. Metal plating is effected by chemical deposition of the metal or by electroplating. The resulting metal layer is reenforced, if required, also by chemical plating or electroplating. The resulting metal coating has a surprisingly high adhesive strength.

Method of electroplating a conductive layer over an electrolytic capacitor

Abstract: A method is provided for electroplating a solid electrolyte film-forming metal capacitor. The method includes placing an electroprocessed capacitor in an electroplating vessel which contains a plating source and electroplating solution, providing a voltage source and connecting the positive terminal of the voltage source to the anode side of the capacitor and to the plating source and the negative terminal of the voltage source to a conducting layer on the anode body, and then electroplating a layer containing metal over the capacitor. Any metal which can be plated may be used, such metals include electrically conductive metals such as silver, gold, copper, nickel, and mixtures thereof. The electroplated layer over the capacitor provides greater resistance to mechanical shock and allows the welding of a cathode termination means to the electroplated layer of the capacitor.

Palladium electroplating bath, process, and preparation

Abstract: Disclosed is an aqueous plating bath suitable for obtaining electrodeposits of palladium and its alloys. The bath is substantially free of cyanide, nitrate and nitrite, and comprises sulfite ion, palladium in the form of a tetra-coordinated complex with palladium in the +2 oxidation state, an atomic ratio of halide to palladium not in excess of 10, and exhibits a pH of from 7 to 12.

Method for the production of material for printed circuits and material for printed circuits

Abstract: A method for the production of a material for printed circuits is disclosed. A temporary base is coated by electroplating with a thin, unbroken and unpatterned metallic layer having a thickness less than 17 μm and the free surface of said metallic layer is bonded to a final insulating base. The temporary base is thereafter removed and the desired wiring pattern is produced by a process comprising etching of the metal layer. A material for use in production of printed circuits is also disclosed comprising a temporary base which is coated by electroplating with a thin, unbroken and unpatterned metal layer having a thickness less than 17 μm. Said material can comprise a final, insulating base bonded to the free surface of the thin metal layer. The temporary base may be comprised of an aluminum foil coated with a layer of zinc or an aluminum foil to which has been applied zinc and which has the zinc replaced electrochemically by half or partly, by a layer of a metal which is more electro-positive than the metal zinc. In electroplating a thin, unbroken and unpatterned metallic layer onto the temporary base the electroplating takes place in a solution containing copper, pryophosphate and an acid, the pK-value of which is at least 0.8 at 20°C.

Electroplating of recoverable silver from photographic solutions and cell with current control means therefor

Abstract: A system for optimizing current density versus voltage across a device for electroplating recoverablesilver from expended photographic solutions by controlling voltage applied across the electrodes of the device as a controlled function of current flow through the device, current being sensed in terms of voltage across a resistance in series with the device, and that voltage, after comparison with reference voltages being employed to control a voltage regulator in the circuit between a source of dc voltage and the electrodes. The cathode of the device is a removable flexible stainless steel cylinder, and is contained in a cylindrical tank of larger diameter than that of the cathode. The anode is a hollow graphite cylinder on which pivots an arm bearing two stirring paddles which is rotated from interiorly of the anode by means of a magnetic clutch.

Method of removing heavy metals from water and apparatus therefor

Abstract: A method of removing heavy metals such as mercury, nickel, zinc, lead, cadmium, and copper from contaminated aqueous solutions, such as waste waters, including the steps of passing the aqueous solution through an electrochemical cell containing an oxidation resistant anode and a cathode comprising a bed of tin or tin-coated particles; electroplating (and amalgamating in the case of mercury) the heavy metal in solution onto the surface of the tin or tin-coated particles in the electrochemical cell; and discharging the aqueous solution substantially free of heavy metal.

Radiative and Electrical Properties of Exploding Silver Wires

Abstract: The radiative properties of silver wires exploded by capacitive discharge are studied using time-integrated and time-resolved spectroscopy. Discharge current measurements are obtained from a calibrated current shunt and are correlated with time-resolved spectra to obtain a model for the current conduction processes during wire explosions. Two basic explosion mechanisms are described, both of which begin with the conversion of the wire from a conducting solid to a rapidly expanding dielectric cylinder of metal vapor. This results in a rapid reduction of discharge current. Current then may resume in one of two ways. In He at atmospheric and reduced pressure and in air at reduced pressure dielectric breakdown of the gas surrounding the wire occurs with current conduction peripheral to the expanding metal vapor cylinder. In air at atmospheric pressure, dielectric breakdown occurs through the metal vapor. This results in current conduction along the vapor cylinder axis. The advantages of peripheral current conduction for the analysis of metals electroplated on the surface of silver wires are discussed. Parametric studies with Cd-plated silver wires indicate that the intensity of the background continuum can be reduced by nearly 2 orders of magnitude with little effect on Cd line intensities by reducing the pressure from 730 Torr to 50 Torr in He where peripheral current conduction occurs.

Electroforming an endless flexible seamless xerographic belt

Abstract: A method of forming a xerographic belt substrate is provided in which the conductive metal backing is an endless flexible seamless band of nickel. The substrate band is made by electroforming, using a cylindrical mandrel of aluminum with a thin coating of stainless steel, passivated nickel or chromium and an electroplating nickel solution. During the electroforming operation the mandrel is rotated about an anode disposed in the electroplating solution.

Electrolyte and method for electrodepositing rhodium-ruthenium alloys

Abstract: Disclosed is an electroplating bath suitable for depositing a rhodium-ruthenium alloy containing at least 90 weight % rhodium. Rhodium and ruthenium are present in the plating bath in the form of soluble platable compounds in a weight ratio of from 10:1 to 200:1. The deposits obtained by this bath exhibit improved brightness over comparable baths even without the addition of lead, and also exhibit reduced stress as compared to deposits obtained from rhodium-platinum baths.

Horizontal rectilinear type metal-electroplating method

Abstract: A method for electroplating a metal strip to be plated includes continuously running the metal strip through the interior of a plating vessel of a cylindrical form having a rectangular cross section, the upper and lower walls of such vessel being constructed of an insoluble anode material which is to function as an anode, and compulsively circulating a plating solution in a direction counter to the running direction of the metal strip within the plating vessel and an apparatus for carrying out the same, whereby a high speed plating is performed and the replacement of the anodes can be minimized.

Electroplating method and apparatus

Abstract: The interior surfaces of each of a plurality of hollow metal objects are simultaneously electroplated with a uniform layer of electrodeposited metal by positioning an anode centrally within each of the hollow objects and electrically connecting the anodes and the objects being electroplated in series with each other and with a source of an electrolyzing current An electrically conductive electrolyte solution is continuously supplied to the interior of each of the hollow objects and an equivalent quantity of the solution is continuously withdrawn from each of the objects and returned to the source of supply of the solution The electrolyte solution is introduced into and is withdrawn from each object through a conduit that provides a path of high electrical resistance to the flow of an electric current through the electrolyte contained in said conduit so that the stray electrolyzing currents flowing from any of the objects through the solution in the conduit are reduced to a value that will not significantly affect the electroplating operation taking place in the other objects being electroplated

Reduced stresses in iii-v semiconductor devices

Abstract: Substrate tensile stresses resulting from the combination of an electroplated gold or silver heat sink with a metal contact on III-V semiconductor devices, such as GaAs IMPATT diodes, may be substantially compensated by interposing a layer of tungsten under compressive stress between the contact layer and the heat sink Since gold or silver is not easily plated on tungsten, a thin layer of platinum is deposited over the tungsten layer prior to forming the heat sink

Decorative electroplates for plastics

Abstract: A process for electroplating ABS plastic with decorative nickel chrome plate using an essentially all nickel system involving depositing a sublayer of low strength nickel onto a plastic surface which has been made conductive, depositing over said sublayer a super levelling nickel and depositing chromium on the surface. When the ratio of the thickness of the nickel sublayer to the thickness of the super-levelling nickel is at least about 2, the plated plastic is characterized by good appearance, by excellent resistance to thermal cycling and by excellent resistance to the deleterious effect of corrosive media.

Process for electroplating polyoxymethylene

Abstract: An improved process for electroplating polyoxymethylene is provided wherein a shaped article of polyoxymethylene is treated with quinoline or γ-butyrolactone preferably by immersion techniques prior to subjecting the shaped article to surface treatment with an acid etching agent.

Apparatus for electroplating

Abstract: An electroplating roll is provided with a plurality of electrically conductive, contiguous segments insulated from one another and arranged on rotation to make electrical contact consecutively with a synchronously advancing metallic strip submerged in an electroplating bath to feed electric current to the strip. A commutator connects the segments consecutively to a source of electrical potential in a manner such that only segments of the roll which are entirely in contact with the strip are feeding current to the strip. With this electroplating roll, arcing caused by initial contact of the strip with the conductor ring and consequent burning of the strip becomes negligible. Control of electroplating current flow selectively to individual segments of the conductor ring also permits better control of the rate of plating of the strip in contact with the roll.

Method of selective electroplating and products produced thereby

Abstract: A novel method for the selective electrodeposition of a metallic coating onto a base material and the products produced thereby. In the method of the invention, a thin adherent coating of an electrically conductive material is initially applied to the base material to mask off those portions of the material not to be electroplated. The composite thus formed is then placed in a suitable electroplating apparatus wherein a metallic coating such as gold or other precious metal is electrodeposited onto the portions of the composite not covered by the masking material. After electroplating, the masking material may readily be removed from the base material by chemical or mechanical means, or it may be left intact on the plated article to perform a utilitarian or decorative function in the end product application.

Electrodeposition of cermets

Abstract: Modern engineering requirements are frequently near the limits of application of conventional materials. For many purposes, particularly tribological, the most satisfactory solution is frequently the application of a resistant coating to the surface of a common metal. Electrodeposited cermet coatings have proved very satisfactory: some of the factors underlying the cernet electrodeposition process have been investigated. A ceramic particle in contact with an electrolyte solution will carry a charge which may affect the kinetics of the suspended particle under electroplating conditions. Measurerment has been made of this charge on particles of silicon carbide, chrornium diboride and quartz, in contiact with solutions of copper sulphate/ sulphuric acid in terms of the electrokinetic (zeta) potential and also as surface charge density. The methocl used was that of streaming potential and streaming current measurement

Weak acidic bright ductile zinc electrolyte

Abstract: An aqueous acidic zinc bath is used for electroplating bright ductile metallic zinc deposits on metal substrates, said plating bath containing at least one soluble zinc compound capable of being plated by electrolytic deposition and a polypropoxy ether or a polypropoxy-ethoxy ether interpolymer, the amount of ethylene oxide moeity does not exceed 25% by weight of the interpolymer.

Process for the electrodeposition of ductile palladium and electroplating bath useful therefor

Abstract: Non-porous ductile palladium is obtained by electrodeposition from a high chloride bath comprising:

Composition of electroplating bath for the electrodeposition of bright nickel

Abstract: An aqueous, acid electroplating bath which contains as brightening agents the synergistic combination of N-(3-sulfopropyl) pyridinium inner salt and an acetylenic alcohol-ethylene oxide adduct.

Method of improving plating distribution of elnisil coatings

Abstract: An electroplating system for cathodically plating an epitrochoidally shaped internal surface of a rotary engine housing. An anode assembly is provided which is comprised of a perforate walled container of titanium metal or other anodically inert metal to which a voltage potential can be applied; the basket contains anode pieces such as nickel which are shaped to be in intimate contact with each other during the plating operation. The perforate walls of the anode container is shaped from flexible expanded titanium sheet metal interfitted within semi-epitrochoidally aligned grooves respectively machined into titanium plates forming the ends of the anode assembly. The anode walls are thus shaped substantially complimentary to the epitrochoid configuration of the cathode but have a predetermined deviation adjacent the nodes of the trochoid for insuring a uniform but heavy coating thickness under high speed electroplating conditions.

Bright solder plating

Abstract: Disclosed is a method and composition for electroplating a layer of bright solder on a base metal. In addition to soluble divalent tin and lead salts, the bath contains formaldehyde, an aryl primary amine, a condensation product of an aromatic aldehyde and an aromatic amine and a polynuclear aromatic disulfonic acid. Deposits obtained by this bath are not only mirror bright, but exhibit no haze. An important advantage is that the solderability of the deposit may be correlated to its physical appearance.

Making an anode assembly

Abstract: An electroplating system for cathodically plating an epitrochoidally shaped internal surface of a rotary engine housing. An anode assembly is provided which is comprised of a perforate walled container of titanium metal or other anodically inert metal to which a voltage potential can be applied; the basket contains anode pieces such as nickel which are shaped to be in intimate contact with each other during the plating operation. The perforate walls of the anode container is shaped from flexible expanded titanium sheet metal interfitted within semi-epitrochoidally aligned grooves respectively machined into titanium plates forming the ends of the anode assembly. The anode walls are thus shaped substantially complimentary to the epitrochoid configuration of the cathode but have a predetermined deviation adjacent the nodes of the trochoid for insuring a uniform but heavy coating thickness under high speed electroplating conditions.

Corrosion-resistant composite coating to be formed on steel materials and method of forming the same

Abstract: Heretofore, corrosion-resistant coatings on steel materials have been formed as single layers of zinc, lead, tin, copper and so forth or composite layers or alloy layers of these metals, and many improvements have been made in connection with them. However, a coating providing sufficient enough corrosionresistant property has not yet been known. The corrosion-resistant composite coating for steel materials according to the invention is obtained by first forming an electroplating layer of zinc as inner layer, an electroplating layer of copper as intermediate layer and an electroplating layer of tin as outer layer and subsequently heat treating the resultant composite layer to form a Cu-Sn alloy layer intervening between the intermediate and outer layers. The composite coating according to the invention can show very excellent corrosionresistant property. The corrosion-resistant composite coating according to the invention is obtained under unique electroplating conditions and heating conditions. In the electroplating step for forming the outer layer (tin layer), an electroplating liquid with pH of 1 to 4 is used, and in the heating step due care is taken to hold the outer layer practically at a temperature in the neighborhood of the melting point of tin but not in excess of that melting point.

Plating apparatus and method for rotary engine housings

Abstract: An apparatus and method are disclosed for simultaneously highly uniformly electroplating the working surfaces of a plurality of rotary engine housings. Rotary engine housings are vertically stacked in a box around an insoluble hollow perforated conforming anode. The box is substantially closed except for congruent top and bottom openings that are concentric with and slightly larger than the conforming anode. During plating, the box is completely submerged in an electroplating solution. The box openings allow electroplating solution to enter the box and pass into the anode interior through the anode perforations. Electroplating solution is withdrawn from the anode interior and recirculated back to the tank.

Compositions and process for the electroplating of metal or metal alloy coatings of high brightness on a base surface

Abstract: The present invention provides compositions and a process for the electroplating of metal or metal alloy coatings of high brightness on a base surface, and especially coatings of tin or tin-lead alloys having a high brightness. The compositions comprise a 2,4,6 -- substituted phenol, at least one substituent of which includes at least one secondary, tertiary or quaternary nitrogen atom or an alkylene oxide adduct of such phenol and, optionally, an aldehyde and/or a surface -- active compound.