| 摘要 |
An aqueous acidic plating bath for electrodeposition of tin, lead or tin-lead alloys on a substrate is described. The plating baths are free of fluoride and fluoborate ions and comprise (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanolsulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of halogen substituted and dialkoxy and trialkoxy substituted benzaldehydes, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of an auxiliary brightening agent which is at least one of the group consisting of aniline and the amino-, carboxy-, halo-, alkyl- or alkoxy-substituted anilines. Methods for the electrodeposition of tin, lead, or tin-lead alloys from such baths also are described.
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