Abstract: A gold deposition accelerator for electroless gold plating comprising one or more alkali metal compound(s), wherein said alkali metal compound is not a compound comprising only sodium as an alkali metal, and said alkali metal compound is not only halide, only potassium sulfite, or only potassium sodium tartrate of an alkali metal, an electroless gold plating solution comprising said gold deposition accelerator, a gold plating method and a gold deposition accelerating method using the same and the like are provided.

Abstract: Disclosed is a microcrystalline-to-amorphous gold alloy-plated film having excellent electrical properties and excellent mechanical properties. Physical properties including both the advantageous properties of a crystalline structure and the advantageous properties of an amorphous structure can be obtained by allowing a microcrystalline phase and an amorphous phase to exist in a mixed state at a specific ratio. The average particle diameter of the microcrystals is 30 nm or smaller, the volume fraction of the microcrystals is 10 to 90%, the knoop hardness is Hk 180 or more, the specific resistivity is 200 ??-cm or less. In the film, hardness and abrasion resistance can be improved while maintaining a good specific resistivity value and chemical stability both inherent to gold at practically insignificant levels. Therefore, the film is useful as a material for connecting an electric or electronic component such as a connector and a relay.

Abstract: A gold-cobalt based amorphous alloy plated film consisting of a homogeneous amorphous phase not having microcrystals is formed by electroplating conducted by use of an electroplating bath containing a gold cyanide salt in a concentration of 0.01 to 0.1 mol/dm3 in terms of gold, a cobalt salt in a concentration of 0.02 to 0.2 mol/dm3 in terms of cobalt, and a tungstate in a concentration of 0.1 to 0.5 mol/dm3 in terms of tungsten. The gold-cobalt based amorphous alloy plated film obtained consists of a homogeneous amorphous phase not having microcrystals, and has an enhanced hardness while retaining the good contact resistance and chemical stability intrinsic of gold on such levels as to be free of problems on a practical use basis; therefore, the gold-cobalt based amorphous alloy plated film is effective for use as a contact material in electric and electronic component parts such as relays.

Abstract: A gold-cobalt based amorphous alloy plated film consisting of a homogeneous amorphous phase not having microcrystals is formed by electroplating conducted by use of an electroplating bath containing a gold cyanide salt in a concentration of 0.01 to 0.1 mol/dm3 in terms of gold, a cobalt salt in a concentration of 0.02 to 0.2 mol/dm3 in terms of cobalt, and a tungstate in a concentration of 0.1 to 0.5 mol/dm3 in terms of tungsten. The gold-cobalt based amorphous alloy plated film obtained consists of a homogeneous amorphous phase not having microcrystals, and has an enhanced hardness while retaining the good contact resistance and chemical stability intrinsic of gold on such levels as to be free of problems on a practical use basis; therefore, the gold-cobalt based amorphous alloy plated film is effective for use as a contact material in electric and electronic component parts such as relays.

Abstract: An electroless gold plating solution is provided that includes a cyanide compound and ascorbic acid or a derivative thereof, the electroless gold plating solution containing one or more than one deposition accelerator selected from the group consisting of a copper compound, a thallium compound, and a lead compound.

Abstract: An electroless gold plating solution is provided that includes a cyanide compound and ascorbic acid or a derivative thereof, the electroless gold plating solution containing one or more than one deposition accelerator selected from the group consisting of a copper compound, a thallium compound, and a lead compound.