Abstract: A process and apparatus for supplying a soluble metal compound to an electrolyte solution uses a powder wetting device in a loop from a working tank. The powder wetting machine supplies the powdered metal compound directly into the electrolyte solution which rapidly dissolves to replenish the electrolyte compound during the treating process. The process and apparatus are particularly suitable for replenishing the metal salts consumed during an electroplating process.

Abstract: The invention relates to a method and an apparatus for producing an electrode coating. The fundamental idea of the invention is to regulate in a time-defined manner at any instant during an electrolytic deposition process the concentration of the electrolyte constituents and additives in that in the electrolytic bath are provided additional electrodes, through which specific electrolyte constituents and/or additives can be taken up and/or delivered in time-controlled manner.

Abstract: A process for electrochemical oxidation of aldehydes to esters is provided. The invention includes electrooxidation at a pH where an intermediate hemiacetal is favored, thereby providing for maximum selectivity to the desired ester and for maximum reaction efficiency. In particular, the invention provides for the electrooxidation of acetaldehyde to methyl acetate. The invention is illustrated with reference reactants native to the carbonylation process for the manufacture of acetic acid. Processes described herein are readily adapted to an industrial scale, particularly for the removal of acetaldehyde from process streams.

Abstract: A process for the regeneration of a plating bath comprising trivalent chromium involves the use of platinum anode and a copper cathode wherein the anode to cathode ratio is greater than 2:1 upon passage of a charge having a current density of at least 10 Amperes/diameter2 of exposed cathode. An apparatus for conducting the process is also disclosed. The described process obviates the need for an ion exchange resin and is conducted without the formation of any deleterious toxic sludge.

Abstract: Recovery of silver from a photographic fixer solution in an electrolytic cell is controlled so as to maintain a high current efficiency whilst minimizing unwanted side effects. The rate of change of plating voltage at constant current through the cell is monitored, and in response to detection of a maximum value thereof the current is reduced to a new constant level. Such control allows the cell to be operated continually at high current efficiency in response to changing chemical conditions within the cell.

Abstract: A process for recycling a reaction system of electroplating passivation of wafers, in which lanthanum hydroxide (La(OH)3) or magnesium hydroxide (Mg(OH)2) is added to supplement the lanthanum ion or magnesium ion consumed in an electroplating solution when the pH of the electroplating solution decreases to a range from 0.1 to 0.4.

Abstract: An apparatus for monitoring and adding solution to a plating bath and controlling the quality of deposited metal. At least one monitor monitors at least one condition within a plating bath and produces at least one signal corresponding to the at least one condition. At least one controller receives the at least one signal produced by the at least one monitor, processes the at least one signal, determines whether an additional amount of at least one chemical should be added to the plating bath, and controls at least one valve for controlling flow of the additional amount of the at least one chemical. A pre-mix tank pre-mixes chemicals to be added to the tank. A plurality of holding tanks holds chemicals and supplies the chemicals to the pre-mix tank. At least one valve is arranged between each holding tank and the pre-mix tank. At least one valve is also arranged between the pre-mix tank and the plating bath.

Abstract: The invention relates to a method for the electrolytic deposition of metal coatings, in particular of copper coatings with certain physical-mechanical and optical properties and uniform coating thickness. According to known methods using soluble anodes and applying direct current, only uneven metal distribution can be attained on complex shaped workpieces. By using a pulse current or pulse voltage method, the problem of the coatings being of varying thickness at various places on the workpiece surfaces can indeed be reduced. However, the further problem of the geometric ratios being changed continuously during the depositing process by dissolving of the anodes is not resolved thus. This can be avoided by using insoluble anodes.

Abstract: The invention relates to a method for maintaining constant concentrations of substances contained in an electrolytic treatment bath, preferably in baths with aqueous solutions. In order to regenerate the continual depletion of chemicals, substance concentrates are added to the baths according to known methods. The rapid increase in concentrations of damaging substances in the processing solution is disadvantageous. In order to reduce this build-up, a further metering method is known, namely the continuous replacement of bath solution by creating a bath overflow. The addition of bath solution with the bath concentration is balanced out by the overflow. As a consequence of evaporation and entrainment this method also leads to the fact that the operating concentration cannot be maintained for a long period of time in chemically critical baths.

Abstract: A method and apparatus for enriching the chromium concentration in an operating chrome plating from a spent chrome plating solution containing hexavalent chromium, trivalent chromium and extraneous metal ions is dislosed. A spent platining solution vessel is divided into an anode chamber and a cathode chamber by a porous container. A hollow primary anode is provided in the anode chamber and a plurality of cathodes are provided in the cathode chamber. A circularly shaped secondary anode is provided in the cathode chamber surrounding the cathodes and porous container. The primary anode and cathodes are connected to a primary electric circuit and the secondary anode and the cathodes are connected to a secondary electric. Operating solution from an operating plating vessel containing hexavalent chromium at a pre-enriched concentration is pumped to the anode compartment and hexavalent chromium enriched anolyte is flowed from the anode compartment to the operating plating vessel.

Abstract: Disclosed is a process for supplying nickel ions for a nickel alloy electroplating bath so as to replenish nickel ions consumed as electroplating progresses. The process uses an electrolysis cell, which is equipped with a rotatable cathode in the form of a drum or a disk having a surface of titanium or hard chromium plating; and an anode made of a titanium basket in which sulfur-containing metallic nickel is contained. Spent electroplating solution is electrolyzed in the electrolysis cell to dissolve nickel in the anode basket into the solution as ions and deposit a part of the dissolved nickel on the cathode, which is removed therefrom as the cathode rotates, while the rest of the dissolved nickel remains in the solution. The solution thus replenished with nickel ions is reused for the electroplating. The process may also be used to provide cobalt ions to replenish a spent cobalt alloy electroplating solution.

Abstract: A plating system and method is provided for electroplating silicon wafers with copper using an insoluble anode wherein the electrolyte is agitated or preferably circulated through an electroplating tank of the system and a portion of the electrolyte is removed from the system when a predetermined operating parameter is met. A copper containing solution having a copper concentration greater than the copper concentration of the removed portion is added to the copper plating system simultaneously or after electrolyte removal, in a substantially equal amount to the electrolyte removed from the system and balances the amount of copper plated and removed in the removal stream. In a preferred method and system, an electrolyte holding tank is provided which serves as a reservoir for circulating electrolyte. The addition of the copper containing solution and removal of working electrolyte is also preferably made from the holding tank.

Abstract: A copper replenishment system for replenishing copper which is depleted from a copper plating solution. The replenishment is achieved by the use of a compact filter cartridge, which is inserted into a recirculating loop for the solution. The filter cartridge contains a chemical, which when reacting with the solution replenishes the copper into the solution. The filter cartridge is a compact unit which can be easily handled and reduces the amount of contaminants that could be introduced by the presence of the replenishment chemical.

Abstract: A process and apparatus for electrolytically depositing a uniform metal layer onto a workpiece is provided. The workpiece, for example a circuit board, serves as a cathode. The anode is insoluble and dimensionally stable. Both anode and cathode are immersed in a plating solution contained in an electrolytic container. The solution includes (a) ions of the metal to be deposited on the workpiece, (b) an additive substance for controlling physical-mechanical properties of the metal to be deposited, such as brightness, and (c) an electro-chemically reversible redox couple forming oxidizing compounds when contacting the anode. A metal-ion generator is provided, supplying metal parts of the metal to be deposited onto the workpiece; The plating solution is circulated between the container and the ion generator for maintaining a reaction between the oxidizing compounds and the metal parts for forming metal ions.

Abstract: High aspect ratio openings in excess of 3, such as trenches, via holes or contact holes, in a dielectric layer are voidlessly filled employing a pulse or forward-reverse pulse electroplating technique to deposit copper or a copper-base alloy. A leveling agent is incorporated in the electroplating composition to ensure that the opening is filled substantially sequentially from the bottom upwardly.

Abstract: A process and assembly for stabilizing organic additives in an electrolytic solution while electroplating copper. The process includes forming a protective film on a first surface of an anode and minimizing contact between the electrolytic solution and a second surface of the anode which is further from the cathode than the first surface. An anode housing is used to minimize contact between the electrolytic solution and the second surface of the anode. The housing includes two side walls and a bottom wall, each having a groove, and a sealing back plate. The anode is fitted in the grooves such that the first surface of the anode is in contact with the electrolytic solution and the second surface of the anode abuts against the sealing back plate. The anode housing may be used in an electroplating system including the anode housing, a plating tank containing the electrolytic solution, a cathode immersed in the electrolytic solution, and an anode, which preferably is in the shape of a slab.

Abstract: The invention is directed towards a CO-tolerant fuel cell electrode formed from a carbon supported, platinum dispersed, non-stoichiometric hydrogen tungsten bronze electrode catalyst. The electrode catalyst is capable of oxidizing CO at very low potentials, and is sequentially formed from stable precursors.

Abstract: A zinc-containing waste article is recycled by a method in which the zinc of the waste article is recovered in a molten state while the unmolten nickel/copper electroplating layer of the waste article is dissolved in an acidic solution to form a nickel-zinc alloy or a nickel-zinc-copper alloy electroplating solution.

Abstract: Disclosed is a process of preparing an electrode for a solid polymer electrolyte fuel cell which comprises applying a suspension liquid containing a catalyst and ion exchange resin or a catalyst, Ion exchange resin and hydrophobic resin to an electrode substrate, and forming a catalyst layer by drying, sintering the substrate under pressure characterized in that a high boiling point solvent which cannot be removed during the drying procedure is added to the suspension liquid. In this process, the high boiling point solvent such as glycerin and n-butanol which is not removed during the drying step is present in the pressurizing and sintering steps so that the situation of the catalyst layer is maintained constant scarcely influenced by the conditions of the said steps. The above solvent imparts pertinent softness to the ion exchange resin so as not to fill the pores for gas diffusion in the catalyst layer and to sufficiently bond the pieces of the ion exchange having the role of conducting H.sup.

Abstract: The present invention provides a method of controlling a component concentration of a plating solution in continuously electroplating a metallic strip while controlling a metal ion concentration of the plating solution. In the control method, when a total amount of the plating solution flowing in the series of devices varies from a preselected target value of the total bath amount, a feedback control target value of the metal ion concentration is controlled by changing it to a corrected target value of the metal ion concentration computed on the basis of a preselected target value of the metal ion concentration and said variation in the total amount of the plating solution so that the acid concentration or pH of the plating solution is kept constant. This method is capable of continuously electroplating a metallic strip with high efficiency and high precision.

Abstract: A process for tungsten alloy plating wherein a tungsten replenisher concentrate of tungsten ions pre-complexed with a hydroxy carboxylic acid is used for maintenance additions to the bath. A preferred additive includes from about 100 to about 120 g/l of tungsten ions complexed with from about 120 to about 220 g/l of citric acid. The process provides consistent cathode efficiency and produces ductile deposits of tungsten alloy electroplate.

Abstract: A process for the treatment of a hydrated mixture of a salt which comprises an inorganic fluoride and hydrogen fluoride to remove water from the mixture wherein the salt mixture contains an excess of hydrogen fluoride, which process comprises forming a liquid phase of the said mixture by melting the salt therein and feeding an inert gas through the liquid phase of the mixture.

Abstract: The invention relates to a process for electrolytic treatment of copper foil, comprising the steps of: (A) applying a voltage across an anode and cathode, wherein the anode and cathode are in contact with an electroplating composition containing a gelatin component; (B) removing organic particulate matter by contacting the electroplating solution containing the organic particulate matter with an adsorbent polymer; and (C) electrolytically treating the copper foil. The electroplating composition can additionally contain an active sulfur-containing component, such as thiourea.

Abstract: The invention relates to a method of removing iron compounds and chromium compounds from an aqueous electrolytic solution. Said method is characterized by the following succession of steps:a) adding hydrogen peroxide to the solution and, if necessary, adapting the acidity of the solution so that the pH value of the solution is .gtoreq.7;b) separating the iron hydroxide formed;c) adapting the acidity of the solution so that the pH value of the solution is <4;d) adapting the acidity of the solution so that the pH value of the solution is .gtoreq.7;e) separating the chromium hydroxide formed.The above-described method provides a simple manner of selectively removing chromium compounds and iron compounds from an aqueous electrolytic solution which preferably contains sodium nitrate. The necessary redox reactions take place via oxidation and reduction of C ions by means of hydrogen peroxide.

Abstract: A method of purifying a copper electrolytic solution circulated in a copper electrorefining system, wherein a portion of the solution is withdrawn and recycled to the system after purification treatment. The purification treatment includes the addition of a hydrosulfide to the withdrawn solution to generate only the necessary quantity of hydrogen sulfide gas required in the reaction. The hydrogen sulfide gas generated is utilized for purification treatment. One process comprises dividing the solution withdrawn into two portions. Sodium hydrosulfide is added to the first portion to precipitate and separate metals as sulfides. Excess sodium hydrosulfide is further added to the first portion for reaction with residual sulfuric acid in the solution to generate hydrogen sulfide gas, then contacting the second divided portion with the hydrogen sulfide gas thus produced to precipitate and separate metals in the form of sulfides. The filtrate is then recycled to an electrorefining system.

Abstract: The present invention is to provide a method for treating sludge as a by-product of a process of tin electroplating a steel plate by means of a plating bath containing haloid ions, together with an equipment therefor. More specifically, by immersing the sludge in water prior to filtration, the residual sludge is subjected to alkali hydrolysis in the presence or absence of the ions of an alkali earth metal within a temperature range of 100.degree. to 400.degree. C., whereby cyanide compounds and fluoride compounds contained therein under environmental regulations are prepared into environmentally non-hazardous matters. By adjusting the filtrate to pH 7.5 to 10, the precipitate with the principal component of tin hydroxide is deposited to recover the tin components contained in the sludge. Furthermore, the recovered tin is refined into the metal tin, for recycling and use as the electrode by the plating.

Abstract: An apparatus for simultaneously anodizing the heads of several aluminum pistons includes a plating tank with an array of apertures extending through one side wall, one aperture for each piston; a fixture on the wall providing a cylindrical bore aligned with each aperture adapted to receive a piston; and a plurality of actuators which, when pivoted and locked into alignment with the fixture bores, operate to secure individual pistons in their respective apertures. A masking/sealing assembly within each fixture bore ensures that each aperture is sealed upon the securing of a piston therein, with only the piston's head and peripheral land being placed in fluid communication with the interior of the plating tank. A remote storage tank provides a supply of an electrolyte which is circulated by a fluid supply network between the storage tank and the thus-sealed plating tank during electrolysis. After the desired coating is achieved, the electrolyte is drained from the tank.

Abstract: An electrolytic cell comprising bipolar electrodes is employed for electrochemical deposition of copper, zinc, lead, nickel or cobalt. An interior space is provided between the cathode side and the anode side of a bipolar electrode. The electrolyte can flow substantially without an obstruction through the interelectrode space between adjacent electrodes. The current densities in the interelectrode space amount to 800 to 8000 A/m.sup.2. Gas is evolved on the anode side of the bipolar electrodes and causes liquid to flow along the anode side. In the middle of the height of the anode side that liquid flow has a vertical component having a velocity of 5 to 100 cm/second. Electrolyte solution flows from the upper edge portion of the anode side to a return flow space, in which the solution flows downwardly. From the return flow space the solution is returned to the lower portion of the interelectrode space.

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 a plant for regenerating zinc sulfate electrolyte in steel strip electrogalvanizing processes by precipitating dissolved iron from electrolyte circulating through a coating cell. A partial quantity of the circulating electrolyte to be regenerated is removed from the coating cell and the dissolved iron is oxidized to Fe.sup.3+ by a redox-controlled addition of oxidizing agents. Subsequently, by raising the pH value to the precipitation limit of Fe.sup.3+ by a controlled addition of a ZnO/water suspension or a ZnCO.sub.3 /water suspension, the dissolved iron is precipitated as sludge. Any excess ZnO or ZnCO.sub.3 is then dissolved by adding fresh electrolyte. The precipitated iron sludge is conducted through a suitable filter such as a filter press, a filter belt, a decanter, etc., and the precipitated iron is filtered out in this manner. Subsequently, the purified partial quantity of the electrolyte is returned to the coating cell.

Abstract: The present invention relates to an electrode preferably an insoluble electrode for an electrolytic cell. The electrode is located within an enclosure defining a chamber, a wall of said enclosure being formed by a membrane allowing ions to pass therethrough. The enclosure has an opening for feeding electrolyte, an opening for evacuating electrolyte and means conducting the upward current of electrolyte with a velocity in the vicinity of the electrode of at least 0.01 m/s. The invention relates also to plants and processes using such electrode for the plating or deplating of metal strips.

Abstract: The invention describes a process for the electrolytical coating of an object of steel on one or both sides. Preferably, the object is a steel strip with zinc or a zinc iron alloy. Zinc or a zinc iron alloy is deposited on the object when the object is connected to form the cathode of a galvanic cell in an aqueous solution of zinc chloride and iron chloride with a pH of 0.1 to 3.0. The zinc chloride solution has a concentration of 50 to 1000 g/l for the deposition of metallic zinc. A partial flow of electrolyte solution is past continuously into a column filled with metallic zinc, where the trivalent iron formed there during the electrolysis is reduced to a bivalent iron, and metallic zinc is dissolved simultaneously therewith. The invention also describes an apparatus for the electrolytical coating of an object of steel.

Abstract: A process for electroplating a substrate by coating the substrate with a coating of conductive particles. The coating of conductive particles is applied to the substrate from an unstable aqueous dispersion essentially free of a dispersing agent using physical dispersion means to maintain the stability of the dispersion.

Abstract: An apparatus for continuously dissolving metal powder for use in plating includes a dissolving tank for dissolving metal powder for used in plating solution in a solvent, a filter for separating the solution containing undissolved residue into an undissolved residue and a filtrate, a recovery tank of the filtrate, and a plating solution storing tank for supplying recovered filtrate to a plating tank. The filter is a porous substance having a plurality of liquid passages in the axial direction thereof, and the filter is provided with a circuit for returning a liquid solution containing the undissolved residue passed through the passages to the dissolving tank and a pipeline for leading the filtrate to the recovery tank.A method of dissolving a nickel metal, which has a specific surface of 0.003 m.sup.2 /g or more, is dissolved with the use of the above-described apparatus.

Abstract: A system automated for providing at least periodic removal of metal ions and contaminants from a chemical bath, consists of a microprocessor programmed for controlling fluid circuits of pumps and valves, for in one state of operation circulating a first predetermined quantity of the chemical bath from a first tank, through an ion exchange column, and back to the first tank; for in a second state of operation circulating deigned water from a second tank into the IEX column for displacing residual chemical bath therefrom for return to the first tank; for in a third state of operation circulating deigned water through the IEX column, and discharging the rinse water from a waste port; for in a fourth state of operation circulating regenerate acid through the ion exchange column, and discharging the used acid from a waste port; for in a fifth state of operation circulating deionized water through the IEX column for rinsing acid regenerate therefrom and discharging the same out of a waste port; and for in a sixth s

Abstract: A material handling device for reducing spillage of flowable or particulate material dispensed into a storage bin, the device comprising an upper region defining a first opening for receiving such material and a pair of discharge members extending in a direction opposite the first opening. The device is particularly suited for placement over a horizontal support rod from which the bin is typically suspended from. The device finds wide use in electroplating applications providing methods of maintaining a uniform arrangement of bins in an electroplating tank, and methods of protecting hardware utilized for suspending bins from electroplating tank support rods.

Abstract: Incorporating an additive into a tin electroplating bath substantially inhibits soluble ferrous ions, ferric ions, and stannous ions from reacting thus minimizing the formation of stannic tin which is lost in the plating sludge.

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: This invention relates to a process for making copper wire directly from a copper-bearing material, comprising: (A) contacting said copper-beating material with an effective amount of at least one aqueous leaching solution to dissolve copper ions into said leaching solution and form a copper-rich aqueous leaching solution; (B) contacting said copper-rich aqueous leaching solution with an effective amount of at least one water-insoluble extractant to transfer copper ions from said copper-rich aqueous leaching solution to said extractant to form a copper-rich extractant and a copper-depleted aqueous leaching solution; (C) separating said copper-rich extractant from said copper-depleted aqueous leaching solution; (D) contacting said copper-rich extractant with an effective amount of at least one aqueous stripping solution to transfer copper ions from said extractant to said stripping solution to form a copper-rich stripping solution and a copper-depleted extractant; (E) separating said copper-rich stripping solu

Abstract: An aged tin or tin alloy plating bath is regenerated by adding a water-soluble polymer as a coagulant and a polymeric flocculant to remove sludge.

Abstract: A method of regenerating a nickel-plating electrolytic bath containing nickel sulfamate, prior to nickel plating, comprises the steps of subjecting the bath to a reduction treatment to render the bath unable to be used for electrolytic nickel-plating and slowly oxidizing the bath until it is again suitable for nickel-plating.

Abstract: A Zn-Ni alloy having a high Ni content is used for supplying Ni.sup.2+ and Zn.sup.2+ ions into an acidic plating bath and for supplying Ni and Zn into a hot dip galvanizing bath. This alloy is characterized by being produced by using a flux consisting of a fused-salt former, which forms a salt having a melting temperature of 700.degree. C. or less, and Na.sub.2 B.sub.4 O.sub.7 and occasionaly additionally Na.sub.2 CO.sub.3. By using the inventive alloy, the bath can be quickly prepared, and Zn and Ni can be supplied to the bath without leaving the undissolved residue.

Abstract: This invention is directed to a controlled low profile electrodeposited copper foil. In one embodiment this foil has a substantially uniform randomly oriented grain structure that is essentially columnar grain free and twin boundary free and has an average grain size of up to about 10 microns. In one embodiment this foil has an ultimate tensile strength measured at 23.degree. C. in the range of about 87,000 to about 120,000 psi and an elongation measured at 180.degree. C. of about 15% to about 28%.

Abstract: This invention is directed to an electrodeposited copper foil having a matte-side raw foil R.sub.tm of about 4 to about 10 microns, an ultimate tensile strength measured at 23.degree. C. in the range of about 55,000 to about 80,000 psi, an elongation measured at 23.degree. C. of about 6% to about 25%, an ultimate tensile strength measured at 180.degree. C. in the range of about 30,000 psi to about 40,000 psi, an elongation measured at 180.degree. C. of about 4% to about 15%, and a thermal stability of less than about -20%. The invention is also directed to a process for making the foregoing foil, the process comprising: (A) preparing an electrolyte solution comprising copper ions, sulfate ions, chloride ions at a concentration of about 1.2 to about 4.5 ppm, at least one organic additive at a concentration of about 0.4 to about 20 ppm, and at least one impurity at a concentration of about 0.

Abstract: This is to a process for chromium plating metal articles spray rinsing the metal article after it has been cleaned, acid treated, nickel plated, and chromium plated over rinse tanks which are empty except for the rinse collected therein. The rinse water is recirculated to the respective treating tanks as needed.

Abstract: Carbonates, and particularly sodium carbonate, are removed from cyanide containing plating baths by taking from said cyanide containing bath at least part of its bath liquid; stirring and cooling in a cooling container the token liquid while in the metastabile state until crystallization of the carbonates occurs; separating the crystallized carbonates from the liquid; and leading the residual liquor back to the plating bath. Preferably, the quantity of bath liquid taken from the plating bath and the moment of this taking are chosen so as to bring the carbonate content of said plating bath, after leading the residual liquor back to it, to a carbonate content of 25 to 45 grams/liter, and the cooling is continued until the exothermic reaction, which is caused by the liberation of the heat of crystallization, starts, and thereafter the mixture is still held for 2 to 4 minutes at 0.5.degree. C. to 1.degree. C. below this starting temperature.

Abstract: A specially controlled electrolytic process for regenerating for reuse solutions such as the post activator solution used in the direct metallization process for making printed circuit boards is disclosed whereby the contaminant tin level of the operating solution is controlled at desired levels.

Abstract: The present invention is directed to an expert control system for controlling plating bath parameters. The system uses both feed-forward and feed-backward control to determine the amount and timing of replenisher additions of bath constituents to maintain optimum bath efficiency.

Abstract: A real-time measurement is made of the proportions of solid matter and pigment contained in an electrodeposition coating material in an electrodeposition coating material tank. The attenuation of an ultrasonic wave through the electrodeposition coating material and the density and temperature of the electrodeposition coating material are measured, and a real-time measurement is made of the proportions of the solid matter and pigment by means of calculating these proportions on the basis of the measured ultrasonic-wave attenuation, density and temperature. Furthermore, the composition of the electrodeposition coating material is controlled on the basis of the results of said measurement.

Abstract: A process and apparatus for regenerating a plating bath comprising trivalent chromium cations (a trivalent chromium bath). The bath can be continuously, or more preferably, periodically with an ion exchange resin, preferably a cation exchange resin. A useful apparatus comprises a plating tank containing a trivalent chromium plating bath in communication with an ion exchange bed continuing ion exchange resin.