| 摘要 |
PROBLEM TO BE SOLVED: To provide a substitution type electroless gold plating liquid for ENIG (Electroless Nickel Immersion Gold) with which gold is hard to be precipitated on a gold plating bath tub, a filter or the like, the local erosion of an electroless nickel plating film as a substrate is not caused, also, the substrate nickel plating film is not oxidized, and excellent solder joining strength can be obtained. SOLUTION: The substitution electroless gold plating liquid at least comprises a water soluble gold salt, a heterocyclic compound having three or more nitrogen atoms in the molecule, and a buffer. Its oxidation-reduction potential at 25°C lies in the range of -150 mV to +50 mV. COPYRIGHT: (C)2007,JPO&INPIT
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