Abstract: A method for forming relatively thick composite coatings on a region of the surface of a metallic member includes exposing the surface region to an electrolyte fluid, either by immersion or by spraying the electrolyte against the surface region. A preferred electrolyte fluid is an aqueous solution including an electrolytic agent, a passivating agent and a modifying agent in the form of a solute or a powder suspended in the solution. A voltage signal is applied to induce a current flow of constant magnitude between the metallic member and the electrolyte fluid so that the metallic member interacts with the passivating agent to form a passive oxide layer on the surface region. The voltage signal increases in magnitude until local voltage reaches a breakthrough level across separate highly localized discharge channels along the surface region of the metallic member.

Abstract: A process and apparatus for electrolytically surface-coating special metal workpieces in which the electrolyte is conveyed in a controlled circuit in and around the electrolysis region in that most of it is conveyed at a high flow rate, at a higher inlet pressure, through the space between a cathodically connected workpiece and an anode and a smaller proportion of it is conveyed at a lower flow rate upwards to the rear of the anode away from the cathode. After leaving the electrolysis region the electrolyte is taken into a separate overflow tank and/or in the feed back system.

Abstract: A method and apparatus for depositing emitter material (3) on a wire cathode by means of electrodeposition. An amount (13) of a suspension comprising an alkaline-earth compound is transferred by a drop holder (11) which is positioned around the wire (2), by movement in a direction transverse to a longitudinal axis of the wire (2), whereafter an electric voltage is applied to the drop holder (11) and the wire (2) to deposit the emitter material (3) on the wire (2), after which the drop holder (11) is withdrawn from the wire (2) again. During the electrodeposition process the drop holder (11) and the wire (2) can be moved with respect to each other along sections of the wire (2) where the emitter material (3) has to be deposited.

Abstract: A passthrough method is provided in which the surface of an industrial grade, low-grease precursor made of copper, with a defined surface roughness, is patinated. For this purpose the precursor material, connected as the anode, is passed through an electrolysis bath, containing sodium carbonate and/or sodium hydrogencarbonate as well as sodium sulfite and/or sodium disulfite, with a temperature of 30.degree. C. to 90.degree. C. and a current density of 1 A/dm.sup.2 to 20 A/dm.sup.2 as bath parameters, for a residence time of 10 seconds to 12 minutes. The precursor material is rinsed and then moved through a fixing bath at a temperature of 35.degree. C. to 95.degree. C. for a residence time of 10 seconds to 120 seconds, and lastly, after a further rinsing, is dried. The fixing bath contains at least one of the oxidation agents: hydrogen peroxide (H.sub.2 O.sub.2), potassium chlorate (KClO.sub.3), potassium peroxodisulfate (K.sub.2 S.sub.2 O.sub.8), potassium permanganate (KMnO.sub.4), of copper sulfate (CuSO.

Abstract: According to the present invention, there is provided a method of forming a corrosion-resistant nickel plated steel sheet or strip comprising a base sheet made of a cold rolled steel sheet or strip. A nickel layer is electroplated on at least one side thereof. A part or all of the nickel plated layer forms Fe-Ni diffusion layer. Moreover, the exposure rate of iron on the surface of the nickel plated layer is 4-30%.

Abstract: A technique for utilizing an electric field to initiate electroless deposition of a material to form layers and/or structures on a semiconductor wafer. The wafer is disposed between a positive electrode and a negative electrode and disposed so that its deposition surface faces the positive electrode. A conductive surface on the wafer is then subjected to an electroless copper deposition solution. When copper is the conductive material being deposited, positive copper ions in the solution are repelled by the positive electrode and attracted by the negatively charged wafer surface. Once physical contact is made, the copper ions dissipate their charges by accepting electrons from the conductive surface, thereby forming copper atoms on the surface. The deposited copper have the catalytic properties so that when a reductant in the solution is absorbed at the copper sites and then oxidized, additional electrons are released into the conductive surface.

Abstract: Embodiments of the present invention provide a new method for producing a three dimensional object, particularly suited to microfabrication applications. The method includes the steps of providing a substrate with a conducting interface, an electrode having a feature or features that are small relative to the substrate, and a solution. The solution has a reactant that will either etch the substrate or deposit a selected material in an electrochemical reaction. The electrode feature is placed close to but spaced from the interface. A current is passed between the electrode and the interface, through the solution, inducing a localized electrochemical reaction at the interface, resulting in either the deposition of material or the etching of the substrate. Relatively moving the electrode and the substrate along a selected trajectory, including motion normal to the interface, enables the fabrication of a three dimensional object.

Abstract: A length of electroplated metal foil, typically copper foil is prepared by placing a stationary arcuate anode concentrically with a rotating cathode drum to define a channel therebetween, passing a plating solution through the channel, conducting electricity across the channel for depositing metal on the cathode drum, and separating the metal deposit from the cathode drum. The anode includes a plurality of circumferentially arranged electrode segments formed of a valve metal material and coated with a platinum group metal or oxide thereof. The electrode segments are removably attached and electrically connected to a back plate. The split anode is easy in assembly and disassembly and, hence, in maintenance and repair, has a high degree of precision in configuration and dimensions, and ensures manufacture of copper foil of quality with a minimized variation in thickness during continuous operation.

Abstract: In a device for electrolytically coating one side of metal strips (2), the metal strips to be coated are guided around a rotary cathodic current roller (1), which they contact, and a partially cylindrical, insoluble anode (3) is arranged approximately concentrically around the current roller, at a distance thereof. The interval (4) between the section (21) of the strip guided on the current roller (1) and the anode (3) is delimited in the area of the strip edges (22) by seals (5) which can be oriented in a direction parallel to the axis of the roller. The electrolyte flows through the interval (4).

Abstract: A photoelectrochemical method and apparatus are disclosed for fabricating electronic circuits. An electroplating solution is applied to the surface of a reverse biased p-type semiconductor material, such as NiO. The solution-covered NiO surface is illuminated with a light beam directed by computer aided design data to photoelectrochemically deposit a seed layer of metal in an electronic circuit pattern. The seed layer may be thickened by further deposition in a plating bath to form metallic circuit traces on the NiO. If desired, the metallic circuitry may be transferred from the NiO to an alternate substrate having a low dielectric constant. The porosity of the NiO surface can be adjusted to optimize the metallic circuit adhesion for image retention or ease of transfer. The metallic traces may also be treated to reduce adhesion of subsequently deposited metal that can be transferred readily.

Abstract: An apparatus and method for simultaneously anodizing the heads of several aluminum pistons includes a plating tank having an array of apertures extending through one of its side walls, one aperture for each piston; and means for securing the head of each piston in its respective aperture. A seal disposed in each aperture ensures that the aperture is sealed upon the securing of the piston therein, with only the piston's head being placed in fluid communication with the interior of the plating tank. An acid electrolyte is directed into the plating tank through electrically-conductive sparging nozzles positioned therein opposite the heads of the pistons, thereby forming an electrolytic cell with the pistons as anodes and the sparging nozzles as cathodes. A power supply simultaneously applies a current to the cell, i.e., across the electrolyte via the pistons and sparger nozzles, to effect electrolytic coating of each piston's head.

Abstract: A system for making porous silicon on blank and patterned Si substrates by "immersion scanning", particularly suitable for fabricating light-emitting Si devices and utilizing an open electrolytic cell having a cathode and an opposing anode consisting of a Si substrate on which the porous silicon is to be formed, both disposed, with their opposing surfaces in parallel, in an aqueous HF solution electrolyte contained in the cell. The substrate anode is mounted to be movable relative to the electrolyte so as to be mechanically cycled or scanned in and out of the electrolyte at a programmable rate during anodization. The uniformity, thickness and porosity of the resulting anodized layer on the substrate are determined by the scanning speed, number of cycles, current density, and HF-based electrolyte parameters of the system, and the Si substrate resistivity, conductivity type, and crystal orientation.

Abstract: An apparatus (10) for electrolytic plating of a substrate (44) includes a tank (14) in which a shaft (30) is centrally mounted for rotation about a first axis (28). The shaft carries an arm (40), on the distal end (112) of which is rotatably mounted a fixture wheel (44). The substrate to be plated is carried on the fixture wheel, which rides on an annular track (50) formed on the bottom of the tank around the shaft. A plurality of spaced pins (52) projecting upwardly from the track engage with a plurality of spaced recesses (56) formed about the perimeter (54) of the wheel, so that the wheel rotates about a second axis (64) while revolving around the first axis. The fixture carries a plurality of electrical contact members (46) that contact the substrate. Each contact member is separately supplied with current from a multichannel power supply (22).

Abstract: An apparatus for use in a radial cell-type electrodeposition cell having a radial cathodic conductor roll with a central conductor band for improving the transfer of electric current between the to be plated strip and the conductor band. The apparatus includes a holddown roll which contacts the strip proximate the contact point of the strip and the conductor roll prior to the entry of the strip into the electrolyte bath and a second holddown roll which contacts the strip after the strip has exited from the electrolyte bath. The holddown rolls urge the strip uniformly against the conductor band to improve current transfer to the strip.