| 摘要 |
PROBLEM TO BE SOLVED: To reduce the tendency to form whiskers in a method for electrodepositing a layer of tin or tin alloy on a copper or copper-containing alloy substrate in an electrical device such as a printed wiring board, a lead frame, a semiconductor package, a chip capacitor, a chip resistor, a connector, and a contact. SOLUTION: The method comprises electrolytically treating a substrate with a solution comprising 20 to 80 vol.% phosphoric acid, 50 to 80 vol.% carboxylic acid, an alkali metal hydroxide, and an organic solvent and electrodepositing a layer of tin or tin alloy on a surface of the treated substrate. COPYRIGHT: (C)2004,JPO&NCIPI
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