Abstract: In a method for an automatic control of the galvanic deposition of copper coatings in acid copper bath by measuring a maximal current density and a continual dosing of gloss additives to the bath, the maximal current density is measured by cyclically measuring an actual voltage in the bath and compensating for eventual deviations of the actual voltage from the nominal value by an automatic dosing of the additives by means of dosing devices.

Abstract: In a method for galvanic deposition of smooth and ductile copper from acid copper baths, the metal content of the bath is kept constant by using inert anodes together with soluble anodes. The inert anodes are made of precious metal, precious metal alloys or their compounds. The ratio of the geometric surface of inert to soluble anode should amount to from 1:1 to 1:200, preferably from 1:5 to 1:20. The inert anode may be provided with additional potential, and the acid bath may contain organic thio compounds. The method is useful for building up conductor paths of printed circuits.

Abstract: An improved galvanic acid copper bath for the deposition of shiny coatings, particularly suited for the strengthening of the conductor paths of printed circuits, which comprises the addition to standard electrolytic aqueous solutions of mineral acids and copper salts of (a) an amide of the general formula R--CO--NH.sub.2, where R is an aliphatic or aromatic hydrocarbon monomer or polymer residue, (b) an oxygen-containing high molecular weight compound and (c) an organic sulfur compound with water-solubilizing groups.

Abstract: The tarnish resistance of silver and silver alloy surfaces can be improved by brief contact in a liquid medium with compounds of quadrivalent tin bound by at least one valence to alkyl having 2 to 22 carbon atoms, and by the remaining valences to sulfur, the tin compounds being of the formulas ##STR1## IN SAID FORMULAS R.sub.1, R.sub.2, and R' being alkyl having 2 to 22 carbon atoms, R" being alkyl having 4 to 22 carbon atoms or --CH.sub.2 COOR.sub.3, R.sub.3 being alkyl having 1 to 22 carbon atoms, and n being 1, 2, or 3.