Abstract: Disclosed is a method of fabricating a microelectronic package, especially a microelectronic package having copper circuitization on a dielectric substrate. The method includes depositing copper on opposite surfaces of the package, and then depositing resist atop the copper. The resist is patterned, e.g., by photolithography or screening so that intended circuitization traces are covered by the resist. The exposed copper is etched, and the resist is stripped off of the unexposed copper. The process is characterized in that the etchant is upwardly sprayed onto a downwardly facing first surface of the package for half of the etching cycle, and then the package is rotated so that etchant is upwardly sprayed onto the downwardly facing second surface of the package.

Abstract: A separable and reconnectable connection for electrical equipment is provided that is suitable for miniaturization in which vertical interdigitating members integrally attached and protruding from a planar portion are accommodated in control of damage in lateral displacement that occurs on mating with an opposite similar contact. Displacement damage is averted through accommodating lateral stresses by providing one or more of a conformal opposing contact, by strengthening through coating and base reinforcement and a deformable coating. The contacts are fabricated by physical and chemical processes including sputtering, normal and pulse electroplating and chemical vapor deposition. Pulse electroplating of palladium provides a dendritic deposit of uniform height, uniform rounded points and less branching. The contacts on completion are provided with a surrounding immobilizing material that enhances rigidity.

Abstract: A separable and reconnectable connection for electrical equipment is provided that is suitable for miniaturization in which vertical interdigitating members integrally attached and protruding from a planar portion are accommodated in control of damage in lateral displacement that occurs on mating with an opposite similar contact. Displacement damage is averted through accommodating lateral stresses by providing one or more of a conformal opposing contact, by strengthening through coating and base reinforcement and a deformable coating. The contacts are fabricated by physical and chemical processes including sputtering, normal and pulse electroplating and chemical vapor deposition. The contacts on completion are provided with a surrounding immobilizing material that enhances rigidity.

Abstract: Spent ferric chloride etching compositions are regenerated by electrolysis which includes introducing spent ferric chloride etching composition containing total iron content substantially equal to the original total iron content of fresh etching composition into the anode compartment of an electrolysis cell that contains an anode compartment, a cathode compartment, and an anion-exchange membrane separating the compartments, and applying voltage of +0.6 to +1.5 volts versus a saturated calomel electrode to the anode.

Abstract: A dielectric substrate is conditioned for plating from an electroless metal plating bath by providing the surface or surfaces of the substrate that are to be plated with semiconductor material whereby the semiconductor material, in the case of n-type material, exhibits energy band where the valence band is equal to or higher than and, in the case of p-type material, exhibits energy band where the valence band is equal to or lower than the redox potential of the metallic ions in the electroless plating bath that are to be deposited as metal on the substrate.

Abstract: A rotating disk electrode system operates at constant speed in a solution whose metal ion concentration is held constant at multiple concentrations within a range of concentration. The current at the working electrode is recorded, while the potential at the working electrode is swept at a predetermined rate for each of the concentration values. The diffusion limiting current is determined for each of the concentration values. Then the rotating disk electrode system is operated continuously in a metal plating bath whose metal ion concentration can vary. A voltage applied to the working electrode produces a current at the electrode whose magnitude is compared to the values of the previous calibration to determine the current metal ion concentration. Alternatively, a rotating disk electrode system is operated over a range of speeds in a solution whose ion concentration is held constant over a range of concentration.

Abstract: A copper plating bath containing a sulfur-containing anion other than sulfate anion and/or a selenium-containing anion other than a selenate anion and/or a tellurium-containing anion other than a tellurate anion in an amount sufficient to increase the plating rate, and method for electroplating copper onto a substrate with the plating bath.

Abstract: A substrate such as carbon, graphite, or various semiconductors is coated with a "two-dimensional" thin film form of flat isolated crystallites of platinum, palladium or silver to form a catalyst useful in a fuel cell. The method of formation of the catalyst is to place the substrate in an electrolyte such as H.sub.2 PtCl.sub.6 about 1% and one molar sulfuric acid. The potentiostatic pulse plating method is employed. A high potential pulse of very short duration is followed by a low potential of substantial duration. The very high potential nucleates crystals at various randomly distributed nucleation sites such as imperfections in the surface of the substrate. The resulting catalyst has a large surface area of hexagonal crystals about 20 to 40 Angstroms in diameter.

Abstract: The concentration of an organic additive in a plating bath is determined by providing a polished and constant current density preplated rotating disc cathode, a reference electrode and anode in an electrolytic copper plating bath, passing an electric current from the anode to the cathode and reference electrode; measuring the voltage difference between the cathode and reference electrode; and comparing the difference to values for known concentrations of the organic additive.

Abstract: Fuel cell catalysts which are efficient, long-lived, and refurbishable in-situ include gold carrying a UPD deposit of another element. UPD Ag, Pt, Pd, Ir, Rh or Tl, Pb and Bi on Au crystallites are carried on and bonded to another substrate. The crystallites cause dissociative adsorption of the oxygen molecules so that four electrons are produced per molecule during the reduction reaction which is involved. In an alkaline electrolyte, the catalyst metals such as Pd, Ir, Ag, Rh and Pt show no tendency to poison the counter electrode (counter relative to the other electrode) since each of those metals is a good catalyst for both electrodes. Suitable fuels include methanol (CH.sub.3 OH), formaldehyde (HCHO), and formic acid (HCOOH).