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: 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: 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 method of etching copper and copper alloys by means of an ammoniacal etching solution containing chloride ions and for regenerating this etching solution during this etching process by adding an ammoniacal compound, for example, in the form of ammonium hydroxide or ammonia gas, as well as hydrochloric acid and water to the etching solution in accordance with continuous measurements of the pH-value and the specific gravity of the etching solution.

Abstract: A workpiece is passed through an etching tank, and then through at least an upstream rinsing tank and a downstream rinsing tank. In each of the tanks a respective liquid is pumped up from a sump at the bottom and sprayed over the workpiece as it passes through. Liquid is drawn out of the upstream rinse tank and mixed with regenerator chemicals to replenish liquid lost by the etcher and maintain the liquid in the etcher at full strength. Liquid lost from the upstream rinser in this manner is replenished by introduction into the downstream rinser of fresh water and passage of liquid from the downstream rinser to the upstream rinser through an overflow that maintains a higher liquid level in the downstream rinser than in the upstream rinser.

Abstract: A method of etching copper and copper alloys by means of an ammoniacal etching solution containing chloride ions and for regenerating this etching solution during this etching process by adding an ammoniacal compound, for example, in the form of ammonium hydroxide or ammonia gas, as well as hydrochloric acid and water to the etching solution in accordance with continuous measurements of the pH-value and the specific gravity of the etching solution.