PURPOSE: To eliminate the remaining of development by rear fogging and to obtain a solder resist having a sharp edge shape by forming photosensitive compsn. layers contg. a compd. having an ethylenic unsatd. group, sensitizer or sensitizer system which form free radicals by active light, and a specific rear fogging preventive agent on both faces of a printed circuit board.
CONSTITUTION: The layers of the photosensitive compsn. contg. the compd. having at least one ethylenic unsatd. group, the sensitizer and/or sensitizer system which form the free radicals by active light and the compd. expressed by formula I and/or the compd. expressed by formula II as the rear fogging preventive agent are formed on both faces of the printed circuit board on which conductor patterns are formed; thereafter, both faces are irradiated by imagewise active rays and are thereby developed. (In formula, R1, R2 signify a hydrogen atom, alkyl group or alkoxy group.) The remaining of the development by the rear fogging is thereby eliminated and the printed circuit board having the solder resist which is sharp in the edge shape is obtd.
FUJII TADASHI
TSUKADA KATSUSHIGE