LAYERED STRUCTURE AND LIGHT-SENSITIVE DRY FILM USED IN SAME

摘要

Provided is a layered structure that has, at least, a substrate (1) and a light-sensitive resin layer or cured coating layer (2), containing an inorganic filler (3), formed on top of the substrate. In the light-sensitive resin layer or cured coating layer, the proportion of the inorganic filler is low on the side in contact with the substrate and high on the surface side opposite the substrate, making it possible to keep the coefficient of linear thermal expansion of the entire light-sensitive resin layer or cured coating layer as low as possible while also avoiding losses in resolution, achieving excellent adhesion between the light-sensitive resin layer or cured coating layer and the substrate, and preventing layer separation during PCT or hot-cold cycles. Preferably, the proportion of the inorganic filler in the light-sensitive resin layer or cured coating layer increases continuously or in small increments from the side in contact with the substrate to the surface side opposite the substrate. A light-sensitive dry film containing the abovementioned light-sensitive resin layer is suitable for use as an interlayer resin insulation layer or a solder resist in a printed circuit board.