Nippon Mining & Metals Co., Ltd.

Nikko Materials Company, Limited

Eiji Hino

Masashi Kumagai

An electroless nickel plating liquid capable of forming an underbarrier metal for metal bumps or solder bumps by electroless nickel plating with a uniform film thickness on silicon wafers composed of multiple IC chips contains a water-soluble nickel salt, a reducing agent, a complexing agent, and a pH buffer, wherein_lead ion is contained at 0.01-1 ppm, cobalt ion is contained at 0.01-1 ppm, and a sulfur compound is contained at 0.01-1 ppm.

Electroless nickel plating liquid

The object is to provide an electroless gold plating liquid which has an adequate deposition speed for practical use without containing any thallium or other heavy metal ions, excellent stability of the plating liquid and contains a non-cyanide gold salt as a gold salt, an alkali metal salt or an ammonium salt of sulfurous acid and thiosulfuric acid as a metal complexing agent, a hydroxyalkylsulfonic acid or a salt thereof represented by the following general formula as a reducing agent, and an amine compound, wherein R represents hydrogen, a carboxyl group, or any of a phenyl group, a tolyl group, a naphthyl group, a saturated or unsaturated alkyl group, an acetyl group, an acetonyl group, a pyridyl group and a furyl group which may have a substitutional group, X represents any of hydrogen, Na, K, and NH4, and n is an integer between 0 and 4.

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Kitaibaraki, Japan

Eiji Hino