Abstract: Black- or brown-oxidised copper laminates that are to be integrated into an electrical multilayer laminate in a subsequent process step are electrochemically reduced in order to avoid the formation of so-called "pink rings". To that end, they are connected as the cathode of an electrolysis in a suitable electrolyte. The atomic hydrogen produced in statu nascendi during the electrolysis completely or partially reduces the copper oxide layer on the metallic regions of the copper laminates, whereby the resistance of the surfaces of the metallic regions of the copper laminates to subsequent acid attack is considerably improved. The electrochemical reduction may optionally be coupled with a chemical reduction or precede a chemical reduction.

Abstract: Apparatus for the electroplating of thin plastic films (1), which are provided on one or both sides with a conductive coating and, if appropriate, may be provided with through-holes, comprises a conveying device (20 to 23) which moves the plastic film (1) horizontally in the region of the chamber (6) filled with electrolyte. The bonding devices (9 to 16), which bring the plastic film (1) to cathodic potential, are located outside the chamber (6) in the "dry". The conveying device includes at least one pair of squeezing rolls at both the inlet and the outlet of chamber (6), the circumferential speed of the pairs of squeezing rolls increasing in the direction of movement of the plastic film (1).

Abstract: A plant for the manufacture of feedthrough (through-hole plated) printed-circuit boards or multilayers which comprises four modules (1, 11, 16, 21) through which the objects (3) to be treated are passed in a horizontal continuous process. In the first module (1) the surfaces to be coated are conditioned in an alkaline aqueous solution. An oxidative pre-treatment of the surfaces to be coated takes place in the second module (11). In the third module (16) a coating of organic monomers is deposited on the surfaces to be coated. Finally, in the fourth module (21) the deposited monomers are polymerized to form an electrically conductive coating. The printed-circuit boards or multilayers (3) thus treated and made electrically conductive on the lateral surfaces of the drill-holes are then passed on for the metallization of the lateral surfaces of the drill-holes (FIG. 1).

Abstract: Workpieces containing copper, in particular copper laminated printed circuit boards, are etched in an alkaline etching agent which contains a copper tetramine complex as the active component. After etching, the workpieces are washed with a mainly neutral washing liquid consisting of a solution of the salt required for regeneration of the etching agent. This regeneration salt mainly contains ammonia ions and chloride ions. In a regeneration system connected to the etching machine the etching agent is on the one hand set to the correct pH value with ammonia gas and on the other hand diluted with the neutral mixture resulting from the washing process.

Abstract: An installation for etching objects comprises at least one etching machine, in which metal is etched from the treated objects, the etching medium being enriched with metal. The etching medium is regenerated again in several electrolytic cells by the removal of metal. The electrolytic cells are brought into operation successively in adaptation to different instantaneous etching capacities of the etching machine ("loads"). This takes place by means of a device, which integrates the quantity of the enriched etching medium removed from the etching machine, over a predetermined period of time. A certain limit value of this integral is associated with each electrolytic cell; if this limit value is exceeded, the corresponding electrolytic cell is activated. In this way, the total capacity of the respective electrolytic cells in operation is adapted to the instantaneous load of the etching machine.

Abstract: An installation for etching objects comprises at least one etching machine, in which metal is etched from the objects treated, the etching medium being enriched with metal. The etching medium is regenerated in at least one electrolytic cell by removing metal. Two buffer tanks are located in the lines which connect the etching machine to the electrolytic cell. A first control circuit ensures a substantially constant density of the etching medium in the etching machine. This takes place by the supply of depleted etching medium from the first buffer tank to the etching machine and by the removal of enriched etching medium from the etching machine into the second buffer tank. A second control circuit ensures a substantially constant density in the electrolytic cell by the supply of enriched etching medium from the second buffer tank into the electrolytic cell and by the removal of a corresponding quantity of depleted etching medium from the electrolytic cell into the first buffer tank.

Abstract: In a machine for etching objects, a nozzle assembly carries out an oscillating movement transverse to the conveying direction, in which the objects to be etched are guided through the machine. The device, which produces the oscillating movement, comprises a drive motor, whereof the rotary movement is converted by means of a cam disc into the oscillating movement of the nozzle assembly. The cam disc, on whose outer contour pressure engagement members of the nozzle assembly bear against two diametrically opposed points, has the contour of a cardioid. Due to this, a particularly linear displacement-time characteristic of the oscillation movement between the reversing points is achieved, which contributes to making the etching process more uniform.

Abstract: A machine for treating objects with a treatment liquid, in particular with an etching medium, comprises a nozzle assembly, which is able to move to and fro in the manner of a drawer between a working position within the housing and a maintenance position outside the housing. In the maintenance position, nozzles located on the nozzle assembly are easily accessible for cleaning, for alignment or for being exchanged. A plug-in coupling, by which the nozzle assembly is supplied with the treatment liquid, is automatically detached when the nozzle assembly is moved out and re-closes when the nozzle assembly is guided back into its working position.

Abstract: An apparatus for etching supports that have deposited thereon an etchable metal with an etching medium, which apparatus includes an etching chamber, means to convey the supports with metal deposited thereon through the etching chamber, a plurality of nozzles which are positioned to spray etching medium containing acid on the supports as they move through the etching chamber, a sump for receiving residual etching medium withdrawn from the etching chamber, a first circulating system for circulating residual etching medium from the sump back to the plurality of nozzles, a reservoir for an oxidizing agent, a device for regulating the addition of oxidizing agent into the circulating system in an amount which is stoichiometrically in excess of that required to remove metal from the supports, a chamber containing a metal which will react with the oxidizing agent, a second circulating system for circulating residual etching medium from the sump through the chamber containing a metal, a regenerating chamber to receive

Abstract: In a method for etching material to be etched, which consists at least partly of metal, an acid is used, which attacks the metal solely after the addition of an oxidizing agent directly before the actual etching operation. The addition of the oxidizing agent takes place in a quantity which slightly exceeds the quantity stoichiometrically necessary for removing the entire metal, so that a small residue of oxidizing agent remains in the etching medium dropping from the material to be etched. This residual oxidizing agent is then removed from the etching medium by a special device, which contains an excess of metal able to be etched by the etching medium.

Abstract: In an installation for etching material to be etched consisting at least partly of metal, preferably copper, oxidizing agent is added to the etching medium containing an acid, directly before the actual etching operation, in a quantity which is in a ratio to the quantity required according to stoichiometric calculation for etching the quantity of metal to be removed respectively from the material to be etched. For this a device is provided which emits a first electrical signal. This gives information about the quantity of material to be removed from the material to be etched respectively being processed. A second signal is emitted by a detector when the material to be etched enters the actual etching machine. Both signals are processed by a central control unit. This takes place in such a way that the central control unit emits a third signal which it has ascertained according to a memorized program from the first signal and whenever the detector signal is received.