Abstract: A solution for simultaneously stripping gold and palladium-containing deposits from substrates carrying them is provided, which is capable of efficient operation under practical and desirable conditions, particularly for recovering the precious metal electroplate and flash coatings from electronic components. The solution contains a thallium compound, in addition to a nitrobenzoate derivative, a soluble cyanide, and certain optional ingredients.

Abstract: A bath for electrodepositing gold utilizes, as the essential ingredients of its electrolyte, salts providing the tartrate radical and the carbonate radical. The bath will have a pH value ranging from approximately neutral to highly alkaline, and adjustments to lower the pH will most advantageously be made utilizing tartaric acid. The bath operates with relatively low gold concentrations, and is capable of producing highly pure deposits and highly desirable alloy deposits; it is especially well suited for semi-conductor industry applications.

Abstract: An all-purpose gold cyanide electroplating bath utilizes a cobalt, nickel, or indium hardener as a chelate with the acid form of a methyl vinyl ether/maleic anhydride interpolymer. The bath is capable of producing high levels of hardness in deposits that are substantially pure gold; it is efficient, very stable, resistent to contamination, and it is well-suited for utility at a wide range of current densities.

Abstract: A novel bath is provided for producing bright and relatively stress free electrodeposits of palladium/nickel alloy upon a workpiece. The bath includes, in addition to palladium and nickel ions as ammino complexes, amounts of saccharin and 3-butyne-2-ol that are, respectively, effective to reduce internal stresses and to brighten the deposit.

Abstract: A bath for electroplating hard gold deposits at relatively high current efficiencies comprises an aqueous solution of a phosphate electrolyte, 1-hydroxyethylidene-1,1-diphosphonic acid, metal constituent, alkali metal gold cyanide and a small amount of free alkali metal cyanide. The bath is maintained at a pH of 3.0-13.0 and operated at a current density of 0.1-165 amperes per square decimeter.

Abstract: A bath for electroplating hard gold deposits at relatively high current efficiencies comprises an aqueous solution of an alkali metal dihydrogen phosphate, nitrilotris(methylene) triphosphonic acid, a nickel and/or cobalt phosphate compound, triethanolamine borate, alkali metal gold cyanide and a small amount of free alkali metal cyanide. The bath is maintained at a pH of 3.8-4.5 and operated at a current density of 0.1-20 amperes per square decimeter.

Abstract: An aqueous bath for the electroplating of gold is particularly adapted for plating a gold strike on stainless steel and includes about 2 to 16.5 grams per liter of auric(III) gold in a cyanide complex. Potassium nitrate is employed as an electrolyte and ethylenediamine hydrochloride is added as a complexer. Nickel, cobalt, copper, tin, or indium ions may be present as an alloying ingredient for the gold and pH of the bath is not more than 4.0, preferably not more than 1.5. In the method of preparing the bath, an aqueous solution of potassium gold chloride KAu(Cl).sub.4 and potassium nitrate is prepared. Potassium cyanide is added to the solution and reacts with the potassium gold chloride to form a gold cyanide complex. Ethylenediamine hydrochloride is then added to the solution. The ethylenediamine hydrochloride may include nickel chloride or other salts to provide the alloying metal additives for the gold and hydrochloric acid may be added to adjust the pH.

Abstract: A bath for electroplating substantially pure silver deposits includes 2-240 grams per liter of alkali metal silver cyanide, a water-soluble electrolyte and a water-soluble selenium compound containing selenium in the -2 oxidation state. The bath has a pH of 8-10 and a free cyanide content of less than 1.5 grams per liter. The bath is maintained at a temperature of 18.degree.-24.degree. Centigrade and may be operated to provide current densities of 0.1-75 amperes per square decimeter.

Abstract: An aqueous bath for electroplating a gold/silver alloy includes a water soluble electrolyte such as potassium pyrophosphate, gold and silver present as their respective alkali metal cyanides, and a water soluble brightener system. The water soluble brightener system comprises a selenium compound containing selenium in the -2 valance state and a polyethyleneimine compound. The bath has a pH of about 8 to 10 and may include tetraethanolamine borate ester to decrease the tensile stress of the electrodeposit.

Abstract: An electroplating test cell comprises a tank having a housing supported within it, the housing being divided into an annular anode compartment and an inner cathode compartment. A cylindrical cathode support is mounted for rotation within the cathode compartment and is vertically adjustable therein to vary its position relative to electrolyte flowed within the compartment. The housing is supported near the bottom of the tank so that different levels of electrolyte may be maintained above the housing to provide varying liquid conditions ranging from a static pressure head to spray chamber plating. Rotation speed of the cathode support is variable to simulate different speeds of material movement through a plating bath.