| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a plating film provided with excellent soldering performance of being hard to be deteriorated due to a heat history in particular by incorporating it with a soluble tin salt and a quaternary compd. SOLUTION: As to a thinning film formed by using a plating bath contg. a soluble tin salt and a quaternary compd., the quaternary compd. is oxidized due to a heat history, by which deterioration in the soldering properties in the surface of the film is prevented. This quaternary compd. is represented by the formula. In the formula, R1, R2, R3 and R4 denote a substituted or nonsubstituted alkyl group, a substituted or nonsubstituted alkenyl group, a substituted or nonsubstituted aryl group or a substituted or nonsubstituted aralkyl group, and R1 and R2 and R3 and R4 may mutually form rings. Z+ denotes a nitrogen atom, a phosphorus atom, an arsenic atom or an antimony atom, and X- denotes an anion such as a chloride ion. As the soluble tin salt, a tin alkanesulfonate, or the like, such as tin methanesulfonate can be examplified.</p> |
