| abstract |
The present invention relates to (a) at least one soluble salt and soluble first tin selected from the group consisting of a soluble first tin salt or a copper salt, bismuth salt, silver salt, indium salt, zinc salt, nickel salt, cobalt salt and antimony salt. A mixture containing a salt, and (b) tin containing at least one aliphatic sulfonic acid selected from the group consisting of alkanesulfonic acid and alkanolsulfonic acid, wherein the aliphatic sulfonic acid has a sulfur atom of +4 or less oxidation number in the molecule; and A tin-containing plating bath is provided, wherein the content of the sulfur compound as an impurity containing a compound having a sulfur atom and a chlorine atom in the molecule is a purified aliphatic sulfonic acid having a trace amount or less. According to the plating bath of this invention, the tin plating film or tin alloy plating film which is excellent in reflow property, a film external appearance, etc. can be formed. |