Abstract: An electrolyte solution for the electroforming of metal foil, such as copper, is provided. The electrolyte contains an effective concentration of chloride ions to promote the formation of a uniformly matte surface finish. Foil so formed forms a strong mechanical bond with a dielectric substrate during a subsequent lamination process.

Abstract: A method of imparting tarnish and corrosion resistance to a copper or copper alloy foil in which the foil is first coated with a thin layer of zinc on at least one side. Thereafter, the foil is treated with an aqueous solution of chromic acid and sulfuric acid. The foil may then be rinsed in a dilute basic solution having a pH greater than 8 and then dried.

Abstract: A treatment for metal foil, particularly copper or copper alloy foil, to be used in electrical and electronic applications wherein the bond strength of the foil is improved. The treatment includes applying an aqueous solution of chromic acid phosphoric acid to the foil, rinsing the foil in an aqueous solution having a pH of at least 8 and thereafter forming a plurality of copper or copper oxide dendritic structures on at least one side of the foil. The foil may be further treated by applying a coating of zinc or other suitable material over the dentritic structure and an anti-tarnish treatment applied. The anti-tarnish treatment includes applying a thin coating of zinc to the smooth side of the foil followed by treating the foil with a chromic acid sulfuric acid solution to provide a layer of chromate on both surfaces. The foil is then further treated by rinsing with an aqueous solution of a pH of at least 8 and dried.

Abstract: A process and apparatus for producing metal foil comprises supplying an isotopically polished continuous cathode, a high volume turbulent flow of electrolyte and rigorous filtration to exclude chlorides, sulfides, organics and other impurities from the electrolyte. The foil so produced is free from micro-voids and able to withstand substantially higher biaxial stresses than conventional electrodeposited foil. The micro void free structure also decreases the diffusion rate of an underlying substrate.

Abstract: A method of imparting tarnish and corrosion resistance to a copper or copper alloy foil, particularly wrought foil having one surface roughened by the application of nodules or dendrites. The foil is treated with an aqueous solution of chromic acid and sulfuric acid. The foil may then be rinsed in a basic solution having a pH greater than 8 and then dried.

Abstract: An electrodeposited foil having isotropic tensile elongation properties. The foil is formed by a process and apparatus wherein the plating surface is polished in a random manner. This provides a surface finish on the plating surface having scratches extending in random directions to provide a generally isotropic surface finish.

Abstract: The present invention relates to a heat exchanger assembly having a plurality of heat exchange fluid passageways formed from a modified copper-zinc alloy. The copper-zinc alloy contains from about 21% to about 39% zinc, from about 1% to about 5% nickel, from about 0.02% to about 1% arsenic and the balance essentially copper. In a preferred embodiment, the copper-zinc alloy consists essentially of from about 25% to about 35% zinc, from about 2.5% to about 3.5% nickel, from about 0.03% to about 0.06% arsenic and the balance essentially copper. The heat exchanger assemblies of the present invention have particular utility as motor vehicle radiators.

Abstract: The present invention relates to a process and apparatus for forming a substantially uniform electrodeposit on a metal or metal alloy foil. The apparatus includes a frame assembly for substantially preventing bowing and/or flapping of the metal or metal alloy foil and for promoting substantially uniform electrodeposits by maintaining the gap between the foil and each treatment anode substantially constant. The process and apparatus have particular utility in the treatment of delicate copper foil for use in electronic and electrical applications.

Abstract: The present invention relates to a technique for improving the tarnish and oxidation resistance of copper and copper base alloy materials. The technique of the present invention involves immersing the copper or copper base alloy material in a dilute aqueous chromic acid-phosphoric acid solution. After emerging from the chromic acid-phosphoric acid solution, the copper or copper base alloy material is preferably rinsed with a dilute aqueous caustic solution and dried. Copper and copper base alloy materials treated in accordance with the present invention have particular utility in printed circuit applications.

Abstract: A system for producing continuous lengths of electroformed metal foil or strip having enhanced ductility and a moderately refined grain structure is described. The system includes an anode and a cathode having a moving plating surface at least partially immersed within an electrolytic solution. To obtain the aforementioned improvements in foil or strip properties, the electrolytic solution is sonically agitated in the vicinity of the moving plating surface. Preferably, one or more ultrasonic generators are used to agitate the electrolyte. The generators may be mounted in a variety of locations including within the electrolyte flow path, within one of the anode and the cathode, or in contact with a surface of either the anode or the cathode.

Abstract: The present invention relates to a system and a process for producing improved quality electrodeposited and/or treated metal or metal alloy foil to be used in electrical and electronic applications. The quality of the foil being produced and/or treated by the system is improved by providing each treatment tank in the system with a dual filtration system. The dual filtration system for each tank comprises a filter conditioning loop for substantially continuously withdrawing solution from the tank and removing particulate matter from the withdrawn solution and a system for removing surface impurities from the solution. In a first embodiment, the surface impurities removing system comprises an off-line solution filtration and replenishment system. In a second embodiment, the surface impurities removing system comprises a skimmer floating on the surface of the solution. The present invention has particular utility in systems for producing electrodeposited and/or treated copper foils.

Abstract: The present invention relates to a system and a process for producing improved quality electrodeposited and/or treated metal or metal alloy foil to be used in electrical and electronic applications. The quality of the foil being produced and/or treated by the system is improved by providing each treatment tank in the system with a dual filtration system. The dual filtration system for each tank comprises a filter conditioning loop for substantially continuously withdrawing solution from the tank and removing particulate matter from the withdrawn solution and a system for removing surface impurities from the solution. In a first embodiment, the surface impurities removing system comprises an off-line solution filtration and replenishment system. In a second embodiment, the surface impurities removing system comprises a skimmer floating on the surface of the solution. The present invention has particular utility in systems for producing electrodeposited and/or treated copper foils.

Abstract: The present invention relates to a treatment for improving the adhesive properties of metallic foils to be used in electrical and electronic applications. The treatment of the present invention comprises applying a light substantially uniform layer of metal to at least one surface of the metallic foil just prior to the formation of a plurality of dendritic structures on the surface. The metal layer renders the surface or surfaces to be treated more uniformly electrochemically active and consequently more receptive to the subsequent dendritic treatment. The treatment of the present invention has particular utility in improving the adhesive properties of wrought copper and copper alloy foils. An apparatus for performing the present treatment is also described.

Abstract: The present invention relates to a system for aligning a plurality of rollers in a metal or metal alloy foil production line. The alignment system comprises a reference frame having a longitudinal dimension parallel to the direction of foil travel through the production line and an optical alignment system movably mounted to the frame. The optical alignment system comprises a laser beam generator, beam splitters and a mirror for generating an orthogonal reference frame for aligning each foil contacting roller in the production line.

Abstract: An electroforming apparatus for producing metal foil having a rotating drum cathode and an improved anode construction and a process for using the apparatus are described. The improved anode construction comprises an arcuate anode having a perforated zone. The perforated zone is placed over a manifold for distributing electrolyte into a gap between the cathode and anode for providing a more uniform current distribution and a more uniform foil deposition in the plating region over the manifold as well as other advantages.

Abstract: A process and apparatus for treating a metal foil to enhance its ability to be bonded to a substrate comprise immersing the metal foil in an electrolytic cell having an electrolyte bath solution containing copper and applying a current having regularly recurring pulses and preferably flowing in only one direction to the cell. The current causes a dendritic layer of copper to be deposited on at least one surface of the metal foil at a first current density and bonded thereto at a second current density. The process and apparatus are particularly suited for treating copper foil.

Abstract: A process and apparatus for treating a metal foil to enhance its ability to be bonded to a substrate comprise immersing the metal foil in an electrolytic cell having an electrolyte bath solution containing copper and applying a current having regularly recurring pulses and preferably flowing in only one direction to the cell. The current causes a dendritic layer of copper to be deposited on at least one surface of the metal foil at a first current density and bonded thereto at a second current density. The process and apparatus are particularly suited for treating copper foil.