Electroless nickel plating solution and method
AssigneeC. Uyemura & Co., Ltd.
InventorsHiroki Uchida, Masayuki Kiso, Takayuki Nakamura, Tohru Kamitamari, Rumiko Susuki, Koichiro Shimizu
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Abstract
To an electroless nickel plating solution comprising a water-soluble nickel salt, a reducing agent, and a complexing agent is added a polythionate or dithionite. The invention also provides a high-build electroless gold plating method comprising the steps of immersing a workpiece in the electroless nickel plating bath, thereby chemically depositing a nickel coating on the workpiece, and immersing the nickel-plated workpiece in an electroless gold plating bath, thereby chemically depositing a gold coating on the workpiece.
Claims2
An electroless nickel plating solution comprising a water-soluble nickel salt in an amount of 0.01. to 1 mol/liter, a reducing agent in an amount of 0.01 to 1 mol/liter, a complexing agent in an amount of 0.01 to 2 mol/liter, and a polythionate or dithionite in an amount of 0.01 to 100 mg/liter.
An electroless nickel plating method comprising the step of
- immersing an electronic appliance in an electroless nickel plating bath comprising a water-soluble nickel salt in an amount of 0.01 to 1 mol/liter, a reducing agent in an amount of 0.01 to 1 mol/liter, a complexing agent in an amount of 0.01 to 2 mol/liter, and a polythionate or dithionite in an amount of 0.01 to 100 mg/liter to electrolessly plate nickel film,
- wherein a thin shoulder and nickel plating outgrowth are overcome and a shortcircuiting by bridges is eliminated.
Dependencies are inferred from the claim text.