Photosensitive resin composition, dry film, and printed circuit board having photocured product of photosensitive resin composition

Abstract

The object of the present invention is to provide a photosensitive resin composition capable of forming a photocurable film having excellent plating properties such as alkali developability and gold plating without impairing high sensitivity to ultraviolet rays. The photosensitive resin composition containing (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein the (B) antioxidant contains at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur.

Description

technical field [0001] The present invention relates to a photosensitive resin composition suitable for a coating material, such as an insulating coating material, a dry film having a coating film obtained by applying the photosensitive resin composition to a film, and a film coated with a photosensitive resin composition made by photocuring the photosensitive resin composition. The printed circuit board of the photocured product. Background technique [0002] A conductive circuit pattern of conductors (such as copper foil) is formed on the substrate, and electronic components are mounted on the pads of the circuit pattern by soldering. The circuit portion other than the pads is covered with an insulating coating as a protective film, that is, a solder resist. film covering. As the insulating film, a photocured film of a photosensitive resin composition containing a carboxyl group-containing photosensitive resin and a photopolymerization initiator is used. In addition, an ...

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Problems solved by technology

[0005] However, if an oxime ester-based photopolymerization initiator is used, the sensitivity of the photosensitive resin composition becomes too high, and halation cannot be sufficiently suppressed even if an antioxidant such as a phenolic compound or an organic sulfur compound is added, resulting in, for example, There is room for improvement in alkali developability since small-diameter through-hole openings are not developed.

[0006] In addition, when the photosensitive resin composition is photocured under conditions where the influence of oxygen barrier is small (for example, a resin film such as PET is laminated on the coating film of the photosensitive resin composition), if the oxime ester photopolymer is used, If the polymerization initiator is used, the ultraviolet rays will reach the undesired area of ​​the coating film, so that the photocuring reaction of the coating film will be excessively carried out, and sometimes defects such as scum will be generated in the photocuring film.

If defects such as scum occur in the photocured film, for example, for the photocured film of the photosensitive resin composition formed on the conductor, in the case of implementing plating such as gold plating, unevenness occurs in the plating such as the gold plating film, This in turn sometimes leads to unattached coatings

Therefore, there is room for improvement in plating properties such as gold plating properties in conventional photosensitive resin compositions containing antioxidants such as phenolic compounds and organic sulfur compounds.

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