Patent ID: 7517443

Claim:
A composition to be used in a process for electroplating surfaces with tin, said composition comprising the following components (g/l): Tin (in a form of tin sulfamate) 50-90 Sulfamic acid, free 40-100 Sulfates, in a form of SO 4 2− 0-15 Nitrogen-bearing block copolymer 1-6 of propylene oxide and ethylene oxide said copolymer having a molecular weight of 3950 to 6450, said copolymer further having a number of ethylene oxide links-to-number of propylene oxide links ratio of 1.4-1.2:1.0 at initial buildup of required number of links from propylene oxide followed by oxyethylation, the composition having a pH of 0.6 to 1.1.