| 摘要 |
817,037. Electroplating with copper. DU PONT DE NEMOURS & CO., E. I. Feb. 26, 1957 [April 30, 1956], No. 6470/57. Drawings to Specification. Class 41. In electrodepositing copper from a selenidecontaining copper cyanide plating bath, the bath composition is maintained by adding thereto a pre-formed aqueous solution prepared from cuprous selenide and an alkali or alkaline earth metal cyanide in proportions to provide by weight 0.9 part of cyanide radical per part of cuprous selenide. Preferably solid mixtures of the cyanide and cuprous selenide are dissolved in water to make the solutions. For bright deposits the bath contains 200-1000 p.p.m. of a brightener methylene-bis (naphthalene sulphonic acid) or its alkali metal salts or polymers thereof and the quantity of cuprous selenide should be sufficient to yield 2-50 p.p.m. of selenium. Periodic reverse plating as described and claimed in Specification 630,165, may be employed to obtain uniform deposits. Specification 801,460 and U.S.A. Specification 2,694,677 also are referred to. |
