METHOD FOR DEPOSITING TIN ALLOYS

摘要

An electroplating bath medium for electroplating articles with a tin-cobalt, tin-nickel, or tin-cobalt-nickel alloy comprises: at least one tin salt; an alloying metal salt comprising a cobalt salt and/or a nickel salt; a complexant comprising a hydroxycarboxylic acid or alkali metal salt thereof such as a sodium or potassium gluconate or heptonate complexant; boric acid; and a bath soluble substituted phenolic compound. The current regime applied to the plating bath can include time intervals of direct current and of pulsed current in order to selectively control the deposition of tin by activation or diffusion control.