Abstract: The present invention is concerned with improved means for etching circuit structures on printed circuit board or wafer substrates of copper or copper alloys in a manner effectively removing unwanted copper from such circuit structures leaving behind a smooth copper surface applying an etching solution containing an Fe(II)/Fe(III) redox system and sulfur containing organic additives. It is an advantage of the present invention that the solution can also applied for plating of copper prior to etching.

Abstract: To avoid change in plating performance, even where operation of the plating equipment is interrupted, the properties of the plating solution need to be preserved. For plating equipment having an insoluble anode, add a reservoir (7) for storing a replacement solution to the tank (4) having a metal ion supply source (copper ball (5)) and, upon termination of the plating operation, the entire plating solution is discharged from the tank (4) containing the metal ion supply source, while the solution for replacement is transferred from the reservoir (7) to the empty tank having a metal ion supply source, and immediately prior to the resumption of the plating operation transfer the solution for replacement back to the reservoir (7) and return the plating solution to the tank (4) containing the metal ion supply source.

Abstract: An iron immersion composition of matter is disclosed comprising a compound having a divalent or trivalent iron ion, a compound having a fluoride ion, and a compound having an acid hydrogen ion. A process for treating an aluminum substrate to improve the adhesion of metal layers to the substrate is also disclosed comprising contacting the substrate with the acidic iron immersion composition to produce an iron immersion coating on the alloy, and contacting the iron immersion coating with an etchant to substantially remove the coating and produce a microporous surface on the substrate.

Abstract: A tin immersion composition of matter is disclosed comprising a compound comprising divalent tin ion, a compound comprising fluoride ion, and a compound comprising acid hydrogen ion. A process for treating an aluminum-copper or an aluminum-silicon alloy to improve the adhesion of metal layers to the alloy is also disclosed comprising contacting the alloy with an acidic tin immersion composition to produce a tin immersion coating on the alloy, and contacting the tin immersion coating with an etchant to substantially remove the tin immersion coating and produce an etched alloy surface.