METHOD OF FORMING METALLIC CIRCUIT PATTERN

摘要

PROBLEM TO BE SOLVED: To provide a method by which a metallic circuit pattern in which the adhesive strengths between a polyimide substrate and metallic circuit sections and the interline insulation resistance of a metallic circuit are improved can be formed. SOLUTION: After a photosensitive resin 3 is applied to a precursor layer 2 of polyimide resin formed on the polyimide substrate 1, a patterned resin mask 4 on which the precursor layer 2 of non metallic circuit sections 6 is exposed is formed by exposing and developing the photosensitive resin 3 and the precursor layer 2 is removed from the sections 6. Then the mask 4 is peeled and plated undercoat cores are formed by irradiating the precursor layer 2 with ultraviolet rays 8 under the presence of a hydrogen donor 7. Thereafter, a plated undercoat metallic layer forming step of forming plated undercoat metallic layers 9 by electroless plating and a metallic circuit forming step are performed. The metallic circuit forming step is composed of plating for forming metallic circuit section 5 on the plated undercoat metallic layers 9 and imidization for heat-imidizing the precursor layer 2 into a polyimide resin layer.