Effect of the structure of aromatic disulphides on some physico-mechanical properties of electrodeposited copper coatings

Abstract

The effect of a series of disulphides (diphenyl, dibenzyl, dinaphthyl and di(naphthylmethyl) with sulpho, dimethylamino, hydroxy or oligoethoxylated hydroxy substituents) on the physico-mechanical properties (ductility, tensile strength, microhardness, brightness and levelling) of copper coatings deposited from sulphuric acid electrolytes has been studied. The amount of codeposited carbon and sulphur was also measured. The aromatic disulphides generally gave coatings of better quality than those obtained in the presence aliphatic disulphides studies previously. Strongly enhanced ductility (up to 40%) and reflectivity (∼80%) were achieved in the presence of dimethylamino derivatives. The ductility of the coatings, in contrast to the tensile strength, appears to be correlated to the amounts of codeposited carbon and sulphur.