GB845570A - Electrodeposition of copper - Google Patents

Abstract

845,570. Electrodepositing bright copper. HANSON VAN WINKLE-MUNNING CO. March 7, 1958 [March 14, 1957(2)], No. 7430/58. Class 41. Bright copper is electrodeposited from an aqueous alkaline cyanide copper plating bath containing (a) either from 0À001 to 1 millimol per litre of an alkali-soluble tellurium compound or from 0À01 to 20 millimols per litre of an alkali-soluble selenium compound and (b) from 1 to 250 millimols per litre of a watersoluble acetylenic compound. The bath may contain as additive (a) 0À001 to 1 millimol per litre of the tellurium compound together with 0À001 to 10 millimols per litre of the selenium compound. The additives (a) may be organic or inorganic preferably a tellurite or tellurate in the case of tellurium and sodium selenide or potassium selenocyanate as the selenium compound. The acetylenic compound may be of the formula (Ra)(Rb)(Rc)C-C=-C-R d where Ra and R b are chosen from hydrogen, alkyl, and hydroxysubstituted alkyl; R c is chosen from hydroxy, hydroxy-methyl orethyl, methoxy, ethoxy, and hydroxyethoxy; and R d is chosen from alkyl, alkenyl, alkynyl, or hydroxy-, methoxy-, or ethoxyderivatives thereof, hydrogen, halogen, diethylaminoethyl and morpholinoethyl, or a compound such as the dipotassium salt of acetylene dicarboxylic acid, dimethyl-3-hexyndioate, and acetylenic amines, alkanolamines and ammonium compounds such as proparyglamine, the 3-methyl- or 3-ethyl derivatives of 3-amino-1-butyne, and 1:4(N:N-diethylamino)-2- butyne. The bath may also contain an alkalisoluble nitroxy compound to extend the bright plating current density range, such compounds being inorganic nitrites and nitrates, oximes and nitroalkanes e.g. aldoxime, dimethylglyoxime, nitromethane. Auxiliary brighteners which serves to suppress haze and cloud formation and sequestering agents may also be added to the bath, e.g. lead, typically as tartrates bis-(sulphonaphthyl)-methanes, formaldehydenaphthalene sulphonic acid condensates, wetting' agents such as polyethylene and polyoxyethylene glycols, alkali-soluble nitriles such as succinonitrile, dicyandiamide, #: # <SP>1</SP>-oxydipropionitrile, #-sulphopropionitrile, potassium dicyanoguanidine, polyaminopolycarboxylic acids and their alkali metal and ammonium salts. The copper baths to which the additions are made typically contain tartrates e.g. Rochelle salt.