Claims
- 1. An electroless gold plating solution containing a gold alkali metal cyanide, a boron-based reducing agent, an alkali metal hydroxide as a pH controller, and a lead compound, wherein 0.1 to 10 g/l of a chelating agent and 5 to 99 mg/l of sodium nitrobenzenesulfonate or p-nitrobenzoic acid, or mixtures thereof are added, whereby the sodium nitrobenzenesulfonate or p-nitrobenzoic acid is added as an oxidant to control the action of said reducing agent to reduce undesirable spread of plated areas.
- 2. An electroless gold plating solution as defined in claim 1, wherein the chelating agent is selected from the group consisting of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, and nitrilotriacetic acid.
- 3. An electroless gold plating solution as defined in claim 1, wherein the concentration of lead compound is 0.1 to 50 ppm.
- 4. An electroless gold plating solution as defined in claim 1, wherein the lead compound is selected from the group consisting of lead citrate, lead acetate and lead oxide.
Parent Case Info
This is a continuation of application Ser. No. 08/514,603, filed Aug. 14, 1995 now U.S. Pat. No. 5,614,004.
US Referenced Citations (11)
Foreign Referenced Citations (7)
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52-124428 |
Oct 1977 |
JPX |
55-24914 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
514603 |
Aug 1995 |
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