Abstract: This invention relates to an apparatus including pairs of rollers for supporting pressure rolls in a laminating apparatus. The rollers provide the pressure rolls with a uniform pressure distribution across the width of the pressure roll nip.

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.