Photosensitive resin composition

Abstract

The invention provides a photosensitive resin composition, which is obtained by a sparing method. The photosensitive resin composition is thick, has excellent sensitivity, is resistant to edge subside, and can form a cured coating with excellent appearance, high definition (high size precision), and insulation property. The photosensitive resin composition comprises (A) carboxyl containing photosensitive resin; (B) a photo-polymerization initiator; (C) a reactive diluent; (D) an epoxy compound; (E) bentonite processed by quaternary ammonium salt, which is represented by formula (I): [R1R2R3R4-N]+X-; (F) hydrophobic silicon dioxide; and (G) coloring pigment other than phthalocyanine green; and for each 100 parts by mass of (A) carboxyl containing photosensitive resin, there is 5.0 to 20 parts by mass of (F) hydrophobic silicon dioxide.

Description

technical field [0001] The present invention relates to a photosensitive resin composition suitable for a covering material, for example, a covering material for covering a conductive circuit pattern formed on a substrate such as a printed circuit board, a cured product obtained by curing the same, and a printed circuit coated with the cured product plate. Background technique [0002] In order to form a conductive circuit pattern on the substrate and mount electronic components on the solder pads of the pattern by soldering, use printed circuit boards such as flexible printed circuit boards and rigid circuit boards, and protect the circuit parts other than the solder pads with insulation film (such as solder mask) coating. Therefore, when soldering electronic components on a printed circuit board, solder is prevented from adhering to unnecessary parts, and at the same time, circuit conductors are prevented from being corroded due to oxidation and humidity when they are dir...

AI Technical Summary

Problems solved by technology

[0005] However, if the photosensitive resin composition as the raw material of the insulating protective film is coated thickly as in Patent Document 1, the ultraviolet light is difficult to reach the deep part of the coating film due to the thickness of the coating film, so the thickness of the coating film The sensitivity (especially the sensitivity near the bottom of the coating film) is not sufficient, and there are problems that high definition (high dimensional accuracy) and good line shape may not be obtained

However, if the photosensitive resin composition is applied thickly as described above by the spray coating method, there is a problem of sagging in the coating film and a problem that a good coating appearance cannot be obtained.

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