Abstract: There is provided a method of forming a conductive film having a predetermined pattern in hybrid ICs, high frequency dielectric filters and the like which makes it possible to safely and efficiently perform a series of the steps of preparing an activating catalytic solution for forming a photoreactive film on a base, forming the photoreactive film through the application of the activating catalytic solution, producing an activating catalyst by exposing particular regions of the photoreactive film, developing by flushing away the photoreactive film in unexposed regions, and immersing the base in an electroless plating bath without using an organic solvent and which allows the formation of a plating film having high electrical conductivity and high strength of adherence. A hydrophilic activating catalytic solution is used which is obtained by dissolving copper oxalate, a palladium salt such as palladium chloride into an alkaline solution such as ammonia.

Abstract: There is provided a method of forming a conductive film having a predetermined pattern in hybrid ICs, high frequency dielectric filters and the like which makes it possible to safely and efficiently perform a series of the steps of preparing an activating catalytic solution for forming a photoreactive film on a base, forming the photoreactive film through the application of the activating catalytic solution, producing an activating catalyst by exposing particular regions of the photoreactive film, developing by flushing away the photoreactive film in unexposed regions, and immersing the base in an electroless plating bath without using an organic solvent and which allows the formation of a plating film having high electrical conductivity and high strength of adherence. A hydrophilic activating catalytic solution is used which is obtained by dissolving copper oxalate, a palladium salt such as palladium chloride into an alkaline solution such as ammonia.

Abstract: Disclosed is an activating catalytic solution for electroless plating which makes possible carrying out successive processes efficiently, without using organic solvent, involving preparation of activating catalytic solution for forming substrate film, formation of a photo-sensitive film by providing the activating catalytic solution, creation of activating catalyst by exposure of specific areas of the photo-sensitive film to light, development by rinsing unexposed portions of the photo-sensitive film, and immersion of the substrate in an electroless plating bath. The activating catalyst can be created with high sensitivity to light at small energy of radiation. The activating catalytic solution preferably contains zinc oxalate, a copper salt, palladium salt such as palladium chloride, and an alkaline solution such as an ammonia water. The activating catalytic solution is used for forming a photo-sensitive film on a substrate to be subjected to electroless plating.