abstract |
Tin or tin-lead alloy electroplating bath which comprises (i) a stannous salt or a mixture of a stannous salt and a lead salt, (ii) at least one compound selected from the group consisting of gluconic acid, glucoheptonic acid, alkali metal salts of gluconic acid and glucoheptonic acid, gluconic lactone and glucoheptonic lactone, and (iii) a surface active agent. |