Abstract: A composition for electroplating copper onto a conductive surface comprising a solution soluble copper salt and an acid electrolyte, said copper salt being present in a concentration of from about 1 to 10 grams per liter of solution and said acid being present in a concentration whereby the acid to copper ratio preferably varies between about 30 to 1 and 50 to 1. The composition is especially useful for the plating of walls of cylindrical openings having a ratio of height to diameter of at least 10 to 1 and a length of at least 0.100 inches.

Abstract: A method for determining the effective quantity of an organic additive in an electroplating bath involving passing an inert electrode through a predetermined sequence of voltammetric steps including a step of plating the electrode at a given applied potential, stripping the plated metal at a given applied potential, and conditioning the inert electrode without applied potential; correlating the quantity of additive with the coulombs utilized during the metal stripping step; and using the same predetermined sequence of voltammetric steps for a bath having an unknown quantity of additive.

Abstract: A method for determining the effective quantity of an organic additive in an electroplating bath involving passing an inert electrode through a predetermined sequence of voltammetric steps including a step of plating the electrode at a given applied potential, stripping the plated metal at a given applied potential, and conditioning the inert electrode without applied potential; correlating the quantity of additive with the coulombs utilized during the metal stripping step; and using the same predetermined sequence of voltammetric steps for a bath having an unknown quantity of additive.

Abstract: This invention relates to a process for identifying the external surface or surfaces of an Al alloy of a homogeneous or composite material by electrochemical means. This method involves forming an anodic layer, in situ, on the products to be identified, by electrolysis under predetermined conditions and following or plotting the development of the voltage U at the terminals of the electrolyzer as a function of time t during an intentiostatic test. The shape and relative position of curves U=f(t), thus obtained, allows the various alloys tested to be identified from a comparison of the derived curve from a curve U=f(t) derived from a known sample. The present method has advantages over the earlier methods of marking in that it provides: non-destructive method employable in situ on products which may have large dimensions (coils, plates, sheets, etc.); almost instantaneous identification; high reliability; and is simple and economic to use.

Abstract: A composition for electroplating copper onto a conductive surface comprising a solution soluble copper salt and an acid electrolyte, said copper salt being present in a concentration of from about 1 to 10 grams per liter of solution and said acid being present in a concentration whereby the acid to copper ratio preferably varies between about 30 to 1 and 50 to 1. The composition is especially useful for the plating of walls of cylindrical openings having a ratio of height to diameter of at least 10 to 1 and a length of at least 0.100 inches.Also disclosed is a device for measuring throwing power of a plating solution. The device comprises two anodes and a cathode suspended in a chamber adapted to contain a plating solution. The cathode is suspended between said anodes and comprises two flat electrode portions in electrical contact with each other, in parallel relationship to each other and spaced apart from each other to define a space containing plating solution.

Abstract: A method of testing coating integrity of containers includes the steps of introducing a probe into an electrolytic solution into the container and applying a constantly-increasing voltage to the probe from a source and taking readings of the voltage when the current flow through the container reaches a predetermined level. The apparatus also includes a gripping mechanism for producing a positive contact between the metal in the container and the remainder of the circuit.

Abstract: A method for simultaneously removing and monitoring the removal of a metallic contaminant from the surface of a metallic workpiece is disclosed. The workpiece and a reference electrode are immersed in an electrically conductive cleaning solution. The potential difference between the workpiece and the reference electrode is periodically measured to generate a series of potential difference values. Differences between successive potential difference values of the series are quantified to generate a noise parameter value. The noise parameter value is compared to a reference value, wherein the reference value is indicative of a maximum allowable amount of contaminant, to determine if an amount of contaminant greater than the maximum allowable amount of contaminant is present on the surface of the workpiece.

Abstract: Disclosed is a method for measuring the metal exposure in a resin covering area of a metal container or a constituent member thereof, which comprises contacting the resin covering area of the metal container or the constituent member thereof with a measuring electrode through an electrolytic solution, relatively moving the resin covering area and the measuring electrode in a certain direction while always holding the electrolytic solution between the measuring electrode and the resin covering area, measuring a leak current between the metal substrate of the metal container or constituent member at predetermined pitches and detecting the metal exposure of the resin covering area as leak currents at respective parts discriminately.According to this measuring method, the degree of the metal exposure can be easily measured as the leak current at respective parts discriminately, and statistical processing of the measured leak current values can be easily performed.

Abstract: The effectiveness of organic additives acting as inhibitors during the electrolytic deposition of metals from aqueous electrolytes, which contain organic additives for improving the deposition of metal, is electrically measured. In order to permit an improved and more reliable check of the effectiveness of the inhibitor and to permit a controlled supply of makeup inhibitors at the required rate, a partial stream of the electrolyte is supplied to flow at a constant velocity in a measuring cell provided with at least three wire electrodes having a fresh conductor surface, a measuring current of 5 mA to 1.0 A is supplied to the electrodes and is maintained, and the slope of the plotted cathode potential-time curve in the range from 0.1 to 50 minutes is taken as a measure of the effective conecentration of the inhibitor.

Abstract: An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

Abstract: A method is disclosed for checking and obtaining in a moving mode the continuity of a metal covering on a metal wire of different nature belonging to the group of a wire being treated by a current strength and issuing from a covering bath and wire, the treatment of which is achieved and coming from a storage wheel. The method comprises continuously bringing the coated wire in contact with a volume of electrolyte solution chemically and physically inert with respect to the wire, and in which the sensitive part of a reference electrode is immersed, sliding the wire issuing from the volume against an electrical contact, measuring the electrical potential variations between the electrode and the contact, and when the potential current oscillates, noting the poorly covered wire and increasing the current strength on the wire being treated.

Abstract: The invention describes a method for determining the assay of gold alloy. It utilizes a dynamic electrochemical process. The specimen gold is wetted by a described electrolyte, and a small current anodizes the surface of the specimen for a metered period of time. A potential sensing device is then applied to the charged surface, and a potential decay is observed. The potential decay information is compared with empirical data and by interpolating said potential decay with the empirical data a determination of the karat quality of the gold alloy may be determined. This same method may be used for other precious metals, employing different electrolytes, empirical standards, and potentiometers.

Abstract: The invention relates to an improved electrodeposition process for the recovery of metals by controlling the concentration of certain impurities in the electrolyte. For a zinc sulfate electrolyte, control of only the antimony impurity level below a predetermined value provides an efficient electrodeposition process.

Abstract: A stripping analysis method comprises a preelectrolysis step during which liquid to be analyzed is introduced into a measurement cell at a pulsating rate, a working electrode is vibrated at an ultrasonic frequency, and the voltage potential between the working electrode and a reference electrode is adjusted to a level which allows the substances to be determined to be deposited on the working electrode. After the preelectrolysis step is a stripping step during which the voltage potential between the working electrode and the reference electrode is scanned through the potential range where the substances to be determined are dissolved back to the liquid and current is measured while the liquid in the measurement cell remains essentially undisturbed. The method also comprises an elimination step during which the voltage potential between the working electrode and the reference electrode is adjusted to a level at which the working electrode is regenerated.

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 method for detecting a start point of electroless plating, which comprises the steps of: immersing a couple of metal electrodes in an electroless plating solution; connecting the metal electrodes to a DC power supply to serve as an anode and a cathode, respectively; applying an electric current across the metal electrodes immediately before immersing an object to be electroless plated in the solution thereby causing metal deposition from the solution at the cathode to activate the same; measuring the potential difference between the activated cathode and the object to be plated; and detecting start of the electroless plating of the object from the measured value of the potential difference between the activated cathode and the object. Also disclosed is an apparatus for carrying out the method of the invention.

Abstract: An electroless plating bath is selectively cleaned of organic contaminants. The organic contaminants are detected by measuring the capacitance between a working electrode and counter electrode with a potentiostat. The capacitance measurements are used to indicate the level of organic contaminants. Exposure of the dummy plating surface in the electroless plating bath is controlled such that the exposed surface is directly proportional to the detected level of organic contaminants.

Abstract: Certain continuous methods for monitoring the quality of ZnSO.sub.4 electrolyte lose sensitivity when the electrolyte contains Sb (V). The sensitivity can be increased by electrochemically reducing Sb (V). A sample of electrolyte which contains impurities including Sb (V) and which may also contain polarization affecting agents is passed through a test cell containing an elongated moving cathode having a predetermined area exposed to the electrolyte, an anode and a reference electrode. A substantially constant current in the range of 0.01 to 0.20 A/cm.sup.2 is applied to the electrodes and the cathode is moved with a speed sufficient to obtain measured values of the cathode polarization potential of zinc deposition on zinc.

Abstract: A process for monitoring an electroless plating bath to determine whether it is in a take mode by electrolessly depositing a film of the metal of the plating bath onto a substrate to provide a preplated cathode; providing the cathode, a reference electrode, and an anode in the electroless bath; passing an electric current and varying the voltage difference, plotting the voltage difference versus the current; and comparing the oxidation peak of the reducing agent to the oxidation peak of the reduced state of the metal ion to be plated to thereby determine whether the bath is in a take mode.

Abstract: Internal stress on an object being electroplated is monitored continuously with a gauge. The gauge includes a metal receptor which is employed as a second cathode in the electrodeposition process. A separate plating current is supplied between the anode and second cathode, distinct from the separately controllable current between the anode and object being plates or electroformed. The stress on the second cathode is measured with a strain gauge, and a stress deviation from a desired plating stress is determined. The currents between the anode and first and second cathodes are adjusted in accordance with the measured internal stress on the metal receptor to achieve a desired stress condition.The internal stress is advantageously monitored with a foil resistance strain gauge. The strain gauge is connected to a carrier disposed in parallel with the metal receptor. The carrier is rigidly connected at opposite ends to the metal receptor.

Abstract: Internal stress on an object being electroplated is monitored continuously with a gauge. The gauge includes a metal receptor which is employed as a second cathode in the electrodeposition process. A separate plating current is supplied between the anode and second cathode, distinct from the separately controllable current between the anode and object being plated or electroformed. The stress on the second cathode is measured with a strain gauge, and a stress deviation from a desired plating stress is determined. The currents between the anode and first and second cathodes are adjusted in accordance with the measured internal stress on the metal receptor to achieve a desired stress condition.The internal stress is advantageously monitored with a foil resistance strain gauge. The strain gauge is connected to a carrier disposed in parallel with the metal receptor. The carrier is rigidly connected at opposite ends to the metal receptor.

Abstract: A method for monitoring the minor constituents present in a plating bath solution which affect plating deposit properties. The method involves applying a predetermined dc potential to a working electrode positioned within the plating bath solution. A constant ac signal is superimposed on the dc potential. The dc potential is varied at a predetermined rate over a predetermined range, which includes potentials which plate and strip the plating deposit. The ac current of the applied ac signal is measured between the working electrode and a counter electrode positioned within the plating bath solution as the dc potential is varied over the predetermined range. The measurement of the ac current in relation to varying dc potential is expressed as an ac current spectra or fingerprint. By optimizing all ac and dc measurement variables, spectra are obtained which contain fine structure and which enable the monitoring of minor plating bath constituents which affect plating deposit properties.

Abstract: Methods are provided for analyzing multilayer structures. The multilayer structure is electrolytically anodized at constant current through a plurality of layers of the structure over a predetermined surface area. During the anodization, the change of the anodization voltage or a time derivative thereof as a function of time is monitored as the anodization through the layers occurs to obtain data. The data may be analyzed in several ways to determine whether degradation of the multilayer structure has occurred, to determine the number of layers present in the multilayer structure and to determine the layer thickness of the multilayer structure.The disclosed methods are accurate, inexpensive and rapid.

Abstract: A method for determining current efficiency in a galvanic bath employs a measuring cell within which a sample is introduced from the galvanic bath. In this sample, onto a preferably rotating electrode metal is precipitated. A negative voltage is applied at constant current during a first predetermined time during the precipitating. Thereafter, the precipitated layer is anodically eroded by use of a suitable electrolyte solution upon pole-reversal of the DC voltage. The current efficiency is then calculated.

Abstract: A mask for precisely defining the area of a thin metal layer on a substrate to be deplated during measurement of the thickness of the thin metal layer utilizing a coulometric technique. The mask having an adhesive on one side for securing the mask to the thin metal layer and for preventing the leakage of electrolyte between the mask and the thin metal layer.

Abstract: The intermittent electrolysis of a portion of the used ammoniacal etching solution generates oxygen at the anode which is mixed into the remainder of the circulated etching solution for reoxidation and regeneration before it is returned to the etching chamber. The portion of the solution which goes through the electrolysis cell, and has its metal content reduced, is returned to the beginning of the circulation loop rather than to the etching chamber, in order that the metal content of the circulated solution may be quickly reduced. This reduction is quickly picked up by a metal content measuring device in the branch supplying solution to the electrolysis cell.

Abstract: The indicator terminal for a coulometric measuring device includes a terminal body with a conically shaped inner space that is coaxial with a tubular nozzle situated in the terminal body. The inner space intersects with a contact mouth formed as a cylindrical recess at a base end portion of the terminal body. A measuring edge of the contact mouth is defined at the base end of the terminal body. The tubular nozzle has a terminus at a predetermined distance before the base end of the terminal body near the contact mouth. Centering and supporting means for the tubular nozzle include three ribs that project across the inner space to engage the periphery of the tubular nozzle and extend along the nozzle in helical fashion so as to be nonparallel with the axis of the nozzle. A reinforcement in the terminal body helps prevent distortion of the contact mouth when the terminal is pressed against a metallic surface.

Abstract: The thicknesses of metallic coatings on a surface is coulometrically measured employing a probe for storing electrolyte solution provided with a power supply and indicating and controlling circuits. The probe comprises a cylinder defining a chamber for storage of electrolyte and having at one end a nozzle of capillary size surrounded by a gasket or cuff adapted to be placed in abutment against the surface to be tested. The opposite end of the cylinder is connected to a source of oscillating pressure which imposes on the electrolyte a corresponding movement against the working surface.

Abstract: An electroplating test cell is disclosed which permits the measurement of the throwing power of an acid. The cell comprises a cathode having a member which is surrounded by an insulating tube. The tube redirects the current in the cell, thereby reducing the amount of metal deposited on the cathode. The pattern of metal deposition on the cathode can be used to estimate the throwing power of the acid in the electrolyte.

Abstract: A plating rate monitor includes a Wheatstone bridge, one branch of which is a monitoring resistor formed on a printed circuit board located in the same environment as an object being plated. The resistor undergoes plating at the same rate as the object. Each time the bridge becomes balanced, another resistor branch of the bridge, which is variable, is incremented by a preselected value to upset the balance. As the monitoring resistor in the plating environment undergoes plating, a change in its resistance causes the bridge to become balanced once again and the time interval for achieving this balance, for a calculated plating thickness change of the monitoring resistor, determines the plating rate.

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: An electrode for use in electrochemical reactions such as electrochemical stripping analysis comprises a plurality of generally parallelly oriented and laterally spatially displaced electrically conductive fibers which are separated and held in a core by electrically insulating bonding material which substantially completely fills the lateral spaces between the fibers. The fibers, preferably carbon fibers, have a crystallographic structure of a plurality of maximum electrical conducting planes extending generally parallel to the fiber. The bonding material is substantially electrically insulating and may be a polyester or epoxy resin.

Abstract: An apparatus for enriching a sought element from a solution for flameless atomic absorption spectroscopy includes a constant voltage current source. The solution is enriched by electrodepositing the sought element therefrom and integrating the current with respect to time.

Abstract: A method for concentrating a vapor of a mercury sample solution is carried out by an apparatus having an electrode of amalgam-forming material which electrode is movable from the sample solution to a heated portion within a tube.