METHOD FOR FORMING SN-AG-CU THREE-ELEMENT ALLOY THIN FILM

摘要

PROBLEM TO BE SOLVED: To provide a method for forming an Sn alloy thin film in which the prevention in the generation of whiskers and satisfactory solderability (low melting point) are made consistent. SOLUTION: Disclosed is a method where a base is dipped into a plating bath, and an Sn-Ag-Cu three-element alloy thin film is formed on the whole surface or a part of the base by electroplating. This method is characterized in that the plating bath contains an Sn compound, an Ag compound, a Cu compound, an inorganic chelating agent and an organic chelating agent; the inorganic chelating agent is a metal fluoro complex-based chelating agent represented by the chemical formula (I) below, and is blended at a ratio of 1 to 300 pts.mass to 1 pt.mass of the Ag compound; and the organic chelating agent is porphyrins, and is blended at a ratio of 1 to 200 pts.mass to 1 pt.mass of the Cu compound: MFX(X-Y)-(I) (In the formula, M represents an arbitrary metal, X represents an arbitrary natural number, and Y represents the oxidation number of M). COPYRIGHT: (C)2007,JPO&INPIT