Curable resin composition, dry film, cured material and printed wiring board

Abstract

This invention provides a curable resin composition, as well as a dry film, a cured product, and a printed circuit board using the same. The curable resin composition exhibits sufficient rigidity, is capable of forming a resin layer with good resolution, and is capable of forming a cured product with good adhesion to a substrate. The curable resin composition of this invention comprises: a carboxyl-containing resin with unsaturated bonds, an inorganic filler, a thermosetting resin, and a photopolymerization initiator; the inorganic filler has a specific gravity of 3.5 or higher, and a Young's modulus of elasticity of 50 GPa or higher; the content of the inorganic filler, converted from solids, is 50% to 80% by mass relative to the total curable resin composition; and the concentration of unsaturated bonds is 0.0002 eq. / g to 0.0007 eq. / g relative to the total mass of the curable resin composition.