aldehydfreies aqueous bath for the galvanic deposition of gold and its alloys and a process for the production of gold and goldlegierungsabscheidungen using this bath

摘要

Bath for galvenic deposition of Au or its alloys comprises (1) aurocyanide complex; (b) a moderate reducing agent; (c) complexing agent; (d) is not 1 g/l. As as its water-soluble cpds. and (e) a polyamine of formula R2N(R'-NR)m-R'-NR2 (I) (=1 R gp. is 1-6C aliphatic or aromatic gp. or its hydroxy deriv.; the others are H. R' = 1-5C alkylene or hydroxy deriv.; m = 0-2). The wt. ratio (I): As is 1-5:1. The bath esp. comprises 6-12 g/l Au; 2-100 g/l N2H4; 1-150 g/l complexing agents; 1-20 mg/l As and 1-100 mg/l (I). Used esp. for coating articles with irregular surface shapes, e.g. electronic components for printed circuits. The Au deposits are not subject to discolouration when heated so are soldered without difficulty, and more uniform plating is achieved.