Patent ID: 8048613

Claim:
A solder resist developable with a dilute aqueous alkali solution comprising: (A) a carboxyl group-containing photosensitive resin obtained by reacting (a) a compound having two or more cyclic ether groups or cyclic thioether groups in the molecule with (b) an unsaturated monocarboxylic acid; reacting the product with (c) a polybasic acid anhydride; reacting the resulting resin with (d) a compound having a cyclic ether group and an ethylenic unsaturated group in the molecule; and reacting the product additionally with (c) the polybasic acid anhydride; (B) an oxime ester photopolymerization initiator comprising an oxime ester group represented by the following General Formula (I): (wherein R1 represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a phenyl group; and R2 represents an alkyl group having 1 to 7 carbon atoms or a phenyl group); (C) a compound having two or more ethylenic unsaturated groups in the molecule; and (D) a thermosetting component, wherein the dry film obtained by applying the composition has an absorbance of 0.3 to 1.2 per 25 μm of the film thickness at a wavelength of 350 to 375 nm, the unsaturated monocarboxylic acid (b) comprises (b-1) an acrylic or methacrylic acid and (b-2) a compound represented by the following General Formula (II): where R3 represents a hydrogen atom or a methyl group, m is an integer of 3 to 7, and an average value of n is an integer of 1 to 4.