Tin-cobalt alloy plating treatment agent and tin-cobalt alloy plating method using the same

摘要

PROBLEM TO BE SOLVED: To provide a treatment agent for tin-cobalt alloy plating that is a plating bath having no toxicity, being easy in wastewater treatment and having good stability and has glossy appearance in a wide range from white-based gloss to black-based gloss with good physical properties and to provide a method for tin-cobalt alloy plating using the treatment agent.SOLUTION: The treatment agent for tin-cobalt alloy plating comprises an aqueous solution containing 2-50 g/L of an inorganic or organic tin salt as a tin metal, 0.5-50 g/L of an inorganic or organic cobalt salt as a cobalt metal, 100-300 g/L of a sodium pyrophosphate or a potassium pyrophosphate, 1-30 g/L of an imidazole compound, 0.2-30 g/L of an aldehyde compound and 0.5-10 g/L of an amino acid compound and containing 0.1-2 g/L of a sulfonated pyridine compound, 1-20 g/L of a sulfonated acetylene compound or 0.2-20 g/L of polyethylene glycol having a molecular weight of 200 to 4,000.