Abstract: An electroless palladium plating liquid containing at least hydrazine or a salt thereof as a reducing agent, which has excellent bath stability in the vicinity of acidity to neutrality range, long-term stability, and is capable of suppressing the Pd film deposition rate decrease caused by elution of etching resist. An electroless palladium plating solution of the invention includes a palladium compound, hydrazine or its salt, at least one selected from a group consisting of a compound represented by the following formula (1) or its salt and a compound represented by the following formula (2) or its salt; and a pH of 8 or less, NH2NHCOR1 (1), (NH2NHCO)2(R2)n (2), wherein R1 represents H, NH2, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH2, or an aromatic group, wherein each of these groups may have a substituent; R2 represents (CH2) or an aromatic group, wherein each of these groups may have a substituent; and n represents an integer of 0 to 10.

Abstract: A film formation method is provided with a catalyst film formation step for forming a catalyst film on the surface of a substrate by displacement reduction plating, an intermediate film formation step for forming a palladium plating film on the catalyst film, and a surface film formation step for forming a gold plating film on the palladium plating film.

Abstract: An electroless palladium plating liquid containing at least hydrazine or a salt thereof as a reducing agent, which has excellent bath stability in the vicinity of acidity to neutrality range, long-term stability, and is capable of suppressing the Pd film deposition rate decrease caused by elution of etching resist. An electroless palladium plating solution of the invention includes a palladium compound, hydrazine or its salt, at least one selected from a group consisting of a compound represented by the following formula (1) or its salt and a compound represented by the following formula (2) or its salt; and a pH of 8 or less, NH2NHCOR1 (1), (NH2NHCO)2(R2)n (2), wherein R1 represents H, NH2, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH2, or an aromatic group, wherein each of these groups may have a substituent; R2 represents (CH2) or an aromatic group, wherein each of these groups may have a substituent; and n represents an integer of 0 to 10.

Abstract: An electroless platinum plating solution includes a soluble platinum compound, a complexing agent, a reducing agent, and a halide ion supplying agent, the reducing agent being formic acid.

Abstract: A film formation method is provided with a catalyst film formation step for forming a catalyst film on the surface of a substrate by displacement reduction plating, an intermediate film formation step for forming a palladium plating film on the catalyst film, and a surface film formation step for forming a gold plating film on the palladium plating film.

Abstract: An electroless platinum plating solution includes a soluble platinum compound, a complexing agent, a reducing agent, and a halide ion supplying agent, the reducing agent being formic acid.