JP6421161B2 - Photosensitive resin composition - Google Patents

Description

  The present invention relates to a photosensitive resin composition suitable for a coating material for coating a coating material, for example, a conductor circuit pattern formed on a substrate such as a printed wiring board, and a print coated with a cured product obtained by curing the photosensitive resin composition. The present invention relates to a wiring board such as a wiring board.

  In forming a solder resist film on a printed wiring board, conventionally, an exposure process is performed by a batch exposure method in which a photomask is provided on a coating film of the printed wiring board and the entire surface of the printed wiring board is exposed. However, in recent years, when a photosensitive resin composition coated on a printed wiring board is exposed, exposure by a direct drawing apparatus that draws an image directly using CAD data has attracted attention.

  The photosensitive resin composition used for the conventional batch exposure includes an α-aminoalkylphenone photopolymerization initiator (Patent Document 1) and an acylphosphine oxide photopolymerization initiator (Patent Document 2) as photopolymerization initiators. Etc. were used.

  However, in direct drawing exposure, the exposure is affected by oxygen molecules, so that the photopolymerization reaction hardly progresses inside the coating film, and good sensitivity cannot be obtained. Moreover, since the concealing power of a coating film will become high when a coloring agent is mix | blended with the photosensitive resin composition, it will become difficult to advance a photopolymerization reaction further inside a coating film. As a result, there was a problem that sufficient photocuring could not be obtained in the deep part of the coating film, and an undercut occurred in the cured coating film and the line shape deteriorated. In addition, since the line shape deteriorates, it cannot cope with a fine-pitch circuit pattern, and in some cases, there is a problem that line peeling or chipping occurs. Furthermore, the said problem became more remarkable when a coloring agent was mix | blended. In order to cope with this problem of line shape deterioration, it is necessary to sufficiently photocure even in the deep part of the coating film by increasing the exposure amount in the photocuring process rather than the batch exposure. However, there has been a problem that increasing the exposure amount hinders improvement in production efficiency.

JP 2010-276859 A JP 2011-232402 A

  In view of the above circumstances, the object of the present invention is to have good photo-curing properties up to the inside of the coating film as in the case of collective exposure, without damaging basic characteristics such as electrical insulation, even with exposure by a direct drawing apparatus. It is to provide a photosensitive resin composition capable of obtaining excellent sensitivity, preventing deterioration of the line shape of a cured product, and obtaining excellent resolution.

  An aspect of the present invention is a photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, and (D) a colorant, The (B) photopolymerization initiator has the following general formula

(In the formula, R ₁ represents hydrogen, an alkyl group having 1 to 17 carbon atoms or an alkoxy group having 1 to 17 carbon atoms, R ₂ represents a phenyl group or an alkyl group having 1 to 5 carbon atoms, —O— represents C _m H _2m -CH ₃ and _{-O-C n H 2n -O-} C p H 2p least one substituted phenyl group substituted with a group selected from the group consisting of -CH _3, m is 0 or It is an integer of 1-5, n is an integer of 1-5, p represents 0 or an integer of 1-5.) It is a compound represented by the photosensitive resin composition characterized by the above-mentioned.

  In an embodiment of the present invention, the (B) photopolymerization initiator is (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropan-2-yl) oxy)- It is a photosensitive resin composition characterized by being 2-methylphenyl) methanone O-acetyl oxime.

  In an embodiment of the present invention, the photopolymerization initiator (B) contains 0.1 to 2.5 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. It is a resin composition.

  The aspect of this invention is a printed wiring board which has the photocured film of the said photosensitive resin composition.

  According to the aspect of the present invention, by using a compound represented by the above general formula, which is an oxime ester compound having one carbazole skeleton having a nitro group in one molecule, as a photopolymerization initiator, Even if exposure is performed with a direct-drawing device without impairing basic properties such as the properties of the film, it is possible to obtain a good sensitivity with photo-curing properties up to the inside of the coating film, as in batch exposure. Can prevent the line shape from being deteriorated. In addition, since the line shape of the cured coating film can be prevented from being deteriorated even by exposure using a direct drawing apparatus, even if it is a fine pitch circuit pattern, it is possible to prevent line peeling and defects, and excellent resolution. can get. Furthermore, since the exposure amount by the direct drawing apparatus can be made the same as the exposure amount of the batch exposure, the exposure process of the direct drawing apparatus can be shortened, and the production efficiency is further improved.

  In addition, as a photopolymerization initiator, by using an oxime ester compound having one carbazole skeleton having a nitro group in one molecule, represented by the above general formula, the photocurability up to the deep part of the coating film is further improved. In particular, the sensitivity to each active energy ray at a wavelength of 365 nm and its vicinity, a wavelength of 385 nm and its vicinity, and a wavelength of 405 nm and its vicinity is improved, and more excellent resolution can be obtained.

According to the embodiment of the present invention, as the oxime ester compound represented by the above general formula and having one carbazole skeleton having a nitro group in one molecule, (9-ethyl-6-nitro-9H-carbazole-3- Yl) (4-((1-methoxypropan-2-yl) oxy) -2-methylphenyl) methanone O -acetyl oxime further improves the photocurability in the deep part of the coating film and is excellent Sensitivity is obtained.

  According to the aspect of the present invention, when the photopolymerization initiator represented by the above general formula contains 0.1 to 2.5 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, the direct drawing apparatus A good sensitivity can be obtained even when the exposure amount by the same amount as the exposure amount of the batch exposure, and the deterioration of the line shape of the cured coating film can be surely prevented.

  Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition of the present invention comprises (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, and (D) a colorant. And the said (B) photoinitiator is an oxime ester compound which has one carbazole skeleton which has a nitro group in 1 molecule represented by the said general formula.

(A) Carboxyl group-containing photosensitive resin The carboxyl group-containing photosensitive resin is not particularly limited, and examples thereof include a photosensitive carboxyl group-containing resin having one or more photosensitive unsaturated double bonds. As an example of a carboxyl group-containing photosensitive resin, acrylic acid or methacrylic acid (hereinafter referred to as “(meth) acrylic acid”) is added to at least a part of the epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in one molecule. A radical polymerizable unsaturated monocarboxylic acid such as epoxy (meth) acrylate to obtain a radical polymerizable unsaturated monocarboxylic oxide epoxy resin, and a polybasic acid or Mention may be made of polybasic acid-modified radical polymerizable unsaturated monocarboxylic oxide epoxy resins such as polybasic acid-modified epoxy (meth) acrylates obtained by reacting the anhydride.

  Any polyfunctional epoxy resin can be used as long as it is a bifunctional or higher functional epoxy resin. Although the epoxy equivalent of a polyfunctional epoxy resin is not specifically limited, 2000 g / eq or less is preferable, 1000 g / eq or less is more preferable, 100-500 g / eq is especially preferable. Examples of the polyfunctional epoxy resin include biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, rubber modified epoxy resin such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type, bisphenol. Phenol type novolak type epoxy resin such as F type, bisphenol AD type, cresol novolac type epoxy resin such as о-cresol novolak type, bisphenol A novolak type epoxy resin, cyclic aliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, Glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified novolac type epoxy resin, polyfunctional modified novolak type epoxy resin, phenols and phenolic hydroxyl group Examples thereof include condensate type epoxy resins with aromatic aldehydes. Moreover, what introduce | transduced halogen atoms, such as Br and Cl, to these resin can also be used. These epoxy resins may be used alone or in combination of two or more.

  The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and acrylic acid and methacrylic acid are preferable. The reaction method of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited. For example, the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid can be reacted by heating in an appropriate diluent. it can.

  The polybasic acid and the polybasic acid anhydride are those for introducing a free carboxyl group into the resin by reacting with the hydroxyl group generated by the reaction of the epoxy resin and the radical polymerizable unsaturated monocarboxylic acid. The polybasic acid or its anhydride is not particularly limited, and either saturated or unsaturated can be used. Specific examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, and 3-ethyltetrahydrophthalic acid. 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, Examples include methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid. Specific polybasic acid anhydrides include these anhydrides. Is mentioned. These compounds may be used alone or in combination of two or more.

  The polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin described above can also be used as a carboxyl group-containing photosensitive resin, but if necessary, one carboxyl group is added to the carboxyl group of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin. By using a carboxyl group-containing photosensitive resin in which the radical polymerizable unsaturated group is further introduced by reacting the glycidyl compound having the above-mentioned radical polymerizable unsaturated group and an epoxy group to further improve the photosensitivity. Also good.

  In this carboxyl group-containing photosensitive resin with improved photosensitivity, the radical polymerizable unsaturated group is bonded to the side chain of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin skeleton by the reaction of the glycidyl compound. , The photopolymerization reactivity is further improved, and the resin has excellent photosensitive properties. The compound having one or more radically polymerizable unsaturated groups and an epoxy group is not particularly limited, and examples thereof include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, and the like. In addition, you may have multiple glycidyl groups in 1 molecule. The above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used alone or in combination of two or more.

  Further, as the carboxyl group-containing photosensitive resin, for example, a) an epoxy group of an epoxy resin having two or more epoxy groups in one molecule, b) at least 1 carbon number per carboxyl group is 10 or more. A reaction product of a long-chain fatty acid-modified ethylenically unsaturated group-containing modified epoxy resin is obtained by reacting a seed fatty acid with c) an ethylenically unsaturated group-containing carboxylic acid. D) Polybasic acid anhydride is added to the hydroxyl group (mainly secondary) generated by the reaction of the carboxyl group of the unsaturated group-containing carboxylic acid and the epoxy group of the epoxy resin to introduce a free carboxyl group into the resin. Can be mentioned.

a) Epoxy resin having two or more epoxy groups in one molecule Any epoxy resin having two or more epoxy groups in one molecule can be used as long as it is a bifunctional or more epoxy resin. The epoxy equivalent of an epoxy resin having two or more epoxy groups in one molecule is not particularly limited, but prevents deterioration in photosensitivity and flexibility due to a decrease in the ratio of introduction of ethylenically unsaturated group-containing carboxylic acid and long chain fatty acid. In view of the above, 2000 g / eq or less is preferable, 1000 g / eq or less is more preferable, and 100 to 500 g / eq is particularly preferable.

  Examples of the epoxy resin having two or more epoxy groups in one molecule include biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and silicone-modified. Rubber modified epoxy resin such as epoxy resin, ε-caprolactone modified epoxy resin, phenol novolac type epoxy resin such as bisphenol A type, bisphenol F type, bisphenol AD type, cresol novolac type epoxy resin such as о-cresol novolac type, cyclic fat Polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol-modified novolac type epoxy resin, polyfunctional modified type Examples thereof include a borac type epoxy resin, a condensate type epoxy resin of a phenol and an aromatic aldehyde having a phenolic hydroxyl group, an epoxy resin containing a fluorene skeleton, and an epoxy resin into which an adamantane skeleton is introduced. Moreover, what introduce | transduced halogen atoms, such as Br and Cl, to these resin can also be used.

  Among these, the sensitivity of the photosensitive resin composition, the resolution of the cured product, the flexibility and the low warpage are excellent, and further, good insulating properties and heat resistance can be obtained. A cyclopentadiene type epoxy resin is preferred.

b) Fatty acid having 10 or more carbon atoms per carboxyl group Fatty acid having 10 or more carbon atoms per carboxyl group is an epoxy group of an epoxy resin having two or more epoxy groups in one molecule. By reacting and introducing the long-chain hydrocarbon structure derived from the fatty acid into the resin, the flexibility (flexibility) and insulation of the cured product of the photosensitive resin composition can be improved. The fatty acid having 10 or more carbon atoms per carboxyl group is not particularly limited, and either saturated or unsaturated can be used, and either linear or branched can be used. Examples of the fatty acid include monobasic acids having 10 or more carbon atoms and dibasic acids having 20 or more carbon atoms. From the viewpoint of the balance between flexibility and dryness to touch, the monobasic acids and dibasic acids are mentioned. Is preferably linear or branched having 2 or less side chains having 2 or less carbon atoms.

  In addition, while introducing a long-chain fatty acid structure into the epoxy resin, different epoxy groups of the epoxy resin are bonded to each other via a fatty acid, so that a relatively rigid skeleton of the epoxy resin is derived from the long-chain fatty acid. The structure can be a structure in which a long-chain hydrocarbon skeleton having high flexibility is covalently cross-linked, and thus the structure contributes to the flexibility of the cured coating film and the solder heat resistance. It is preferable to contain a dibasic acid.

  Furthermore, the flexibility and insulation of the cured coating can be further improved by introducing more long-chain hydrocarbon skeletons having high flexibility and insulation properties derived from long-chain fatty acids. In addition to a dibasic acid having 10 or more carbon atoms per unit, a monobasic acid having 10 or more carbon atoms per carboxyl group is used in combination with a fatty acid, a polyfunctional epoxy resin, and an ethylenically unsaturated group. The molecular weight of the reaction product with the group-containing carboxylic acid can be appropriately controlled while improving the composition ratio of the component derived from the long-chain fatty acid. Thus, by appropriately controlling the molecular weight, it is possible to reliably improve the touch-drying property of the coating film after drying, the solubility in weak alkaline developer (that is, developability) and sensitivity in a balanced manner. it can. Moreover, the combined use of a monobasic acid and a dibasic acid can surely contribute to a good improvement in insulation and solder heat resistance.

  It is particularly preferable to include a linear saturated monobasic acid having 18 or more carbon atoms per carboxyl group from the viewpoint of improving the above properties in a more balanced manner by controlling the molecular weight more appropriately.

  The number of carbon atoms per carboxyl group is 8 or more, preferably 10 or more, from the viewpoint of imparting flexibility and insulation to the cured product. On the other hand, the upper limit of the number of carbon atoms per carboxyl group is not particularly limited, but is preferably 24 or less, particularly preferably 22 or less, from the viewpoint of maintaining good developability.

  Specific examples of fatty acids having 10 or more carbon atoms per carboxyl group include monobasic acids such as capric acid (decanoic acid: C10), undecanoic acid (C11), lauric acid (dodecanoic acid: C12), Tridecyl acid (C13), myristic acid (tetradecanoic acid: C14), pentadecylic acid (C15), palmitic acid (hexadecanoic acid: C16), margaric acid (heptadecanoic acid: C17), stearic acid (C18), isostearic acid (C18) , Tuberculostearic acid (C19), arachidic acid (C20), behenic acid (C22), tricosylic acid (C23), tetracosanoic acid (C24), hexacosanoic acid (C26), octacosanoic acid (C28), triacontanoic acid (C30) ) And the like.

  Dibasic acids include eicosane diacid (C20), ethyl octadecanedioic acid (C20), eicosadiene diacid (C20), vinyl octadecaenedioic acid (C20), dimethyl eicosadiene diacid (C22), dimethyleico C36 dimer acid by dimerization reaction of unsaturated fatty acids such as sundioic acid (C22), diphenylhexadecanedioic acid (C28), oleic acid (C18), etc., and hydrogenated olefinic double bond of the dimer acid Examples thereof include hydrogenated C36 dimer acid.

  The above fatty acids having 10 or more carbon atoms per carboxyl group may be used alone or in combination of two or more.

  The reaction method of an epoxy resin having two or more epoxy groups in one molecule and at least one fatty acid having 10 or more carbon atoms per carboxyl group may be a known method, for example, the above epoxy resin And a reaction method in which the fatty acid is heated in a suitable diluent.

  The ratio of fatty acids having 10 or more carbon atoms per carboxyl group in the carboxyl group-containing photosensitive resin (preparation ratio) is not particularly limited. For example, the lower limit is the flexibility and insulation of the cured product. 10 mass% is preferable from the point which improves more, and 15 mass% is especially preferable from the point which improves a softness | flexibility and insulation reliably. On the other hand, the upper limit is preferably 50% by mass, particularly 40% by mass from the viewpoint of maintaining excellent photosensitivity and resolution by appropriately maintaining the amount of the ethylenically unsaturated group-containing carboxylic acid introduced. preferable.

c) Ethylenically unsaturated group-containing carboxylic acid Ethylenically unsaturated group-containing carboxylic acid reacts with an epoxy group of an epoxy resin having two or more epoxy groups in one molecule, and the epoxy resin is reacted with a photopolymerization initiator. A photocurable group is introduced that can be polymerized by the generated free radicals. The ethylenically unsaturated group-containing carboxylic acid is not particularly limited as long as it imparts photocurability to the epoxy resin, and examples thereof include a radically polymerizable unsaturated monocarboxylic acid. Specifically, Examples thereof include carboxylic acids that can introduce an acryloyl group or a methacryloyl group into an epoxy resin, such as acrylic acid, methacrylic acid, β-acryloxypropionic acid, ω-carboxy-polycaprolactone- (meth) acrylic acid, crotonic acid, cinnamic acid. be able to. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is particularly preferable. These may be used alone or in combination of two or more.

  Although the ratio (preparation ratio) of the ethylenically unsaturated group-containing carboxylic acid in the carboxyl group-containing photosensitive resin is not particularly limited, for example, the lower limit thereof maintains the excellent photosensitivity and resolution of the cured product. From the point of view, 2.0 mass% is preferable, and 3.0 mass% is particularly preferable. On the other hand, the upper limit is preferably 10% by mass from the viewpoint of obtaining excellent flexibility and insulation by appropriately maintaining the amount of fatty acid having 10 or more carbon atoms per carboxyl group. 0.0 mass% is particularly preferable.

  The reaction method of the epoxy resin having two or more epoxy groups in one molecule and the ethylenically unsaturated group-containing carboxylic acid is not particularly limited. For example, the epoxy resin and the ethylenically unsaturated group-containing carboxylic acid are appropriately used. A reaction method of heating in a diluent is mentioned.

d) Polybasic acid anhydride The polybasic acid anhydride is formed by reacting the epoxy resin with at least one fatty acid having 10 or more carbon atoms per carboxyl group and the epoxy resin and ethylenic acid. It reacts with the hydroxyl group produced by the reaction with the unsaturated group-containing carboxylic acid to introduce a free carboxyl group into the epoxy resin. The polybasic acid anhydride is not particularly limited, and either saturated or unsaturated can be used. Examples of the polybasic acid anhydride include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methyl Examples thereof include anhydrides of polybasic acids such as hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid. In addition, these compounds may be used independently and may mix and use 2 or more types in order to adjust developability moderately.

  Although the ratio (preparation ratio) of the polybasic acid anhydride in the carboxyl group-containing photosensitive resin is not particularly limited, for example, the lower limit is preferably 5.0% by mass from the viewpoint of improving developability, and 8. 0% by mass is particularly preferred. On the other hand, the upper limit is preferably 25% by mass and particularly preferably 20% by mass from the viewpoint of obtaining excellent insulating properties.

  Furthermore, as a carboxyl group-containing photosensitive resin, for example, an acid-modified urethanized epoxy (meth) acrylate resin may be used. The acid-modified urethanized epoxy (meth) acrylate resin is obtained, for example, by first obtaining an epoxy (meth) acrylate as described above, and the resulting hydroxyl group has two polybasic acids or anhydrides per molecule. It can be obtained by reacting the above compound having an isocyanate group.

  The compound having two or more isocyanate groups in one molecule is not particularly limited. For example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylene biscyclohexyl isocyanate, Examples include diisocyanates such as trimethylhexamethyl diisocyanate, hexane diisocyanate, hexamethylamine diisocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethyl diisocyanate. These compounds may be used alone or in combination of two or more.

  In the present invention, the above-mentioned acid-modified urethanized epoxy (meth) acrylate resin can also be used as a carboxyl group-containing photosensitive resin, but if necessary, the carboxyl group of the above-mentioned acid-modified urethanized epoxy (meth) acrylate resin. Carboxyl group-containing photosensitivity with further improved photosensitivity by further introducing a radical polymerizable unsaturated group by reacting the glycidyl compound having one or more radical polymerizable unsaturated groups and an epoxy group. It is good also as resin.

  The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 30 mg KOH / g, particularly preferably 40 mg KOH / g, from the viewpoint of reliable alkali development. On the other hand, the upper limit of the acid value is preferably 200 mgKOH / g from the viewpoint of preventing dissolution of the exposed area with an alkali developer, and particularly preferably 150 mgKOH / g from the viewpoint of preventing moisture from being cured and preventing deterioration of electrical characteristics.

  Further, the mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 3000 and particularly preferably 5000 from the viewpoint of toughness of the cured product and dryness to touch. On the other hand, the upper limit value of the mass average molecular weight is preferably 200000, particularly preferably 50000, from the viewpoint of smooth alkali developability.

  Examples of commercially available carboxyl group-containing photosensitive resins include Cyclomer P (ACA) Z-251 (Daicel Ornex Co., Ltd.), ZCR-1601H, ZAR-2000, ZFR-1122, FLX- 2089, ZCR-1569H (above, manufactured by Nippon Kayaku Co., Ltd.), Lipoxy SP-4621 (manufactured by Showa Polymer Co., Ltd.), and the like. These resins may be used alone or in combination of two or more.

(B) Photopolymerization initiator In the photosensitive resin composition of the present invention, the photopolymerization initiator as the component (B) is an oxime ester compound having one carbazole skeleton having a nitro group in one molecule, as described below. formula

(In the formula, R ₁ represents hydrogen, an alkyl group having 1 to 17 carbon atoms or an alkoxy group having 1 to 17 carbon atoms, R ₂ represents a phenyl group or an alkyl group having 1 to 5 carbon atoms, —O— represents C _m H _2m -CH ₃ and _{-O-C n H 2n -O-} C p H 2p least one substituted phenyl group substituted with a group selected from the group consisting of -CH _3, m is 0 or An integer of 1 to 5, n is an integer of 1 to 5, and p is 0 or an integer of 1 to 5).

  By using the oxime ester compound represented by the above general formula, even with exposure by a direct drawing device, as in the case of collective exposure, good sensitivity having photocurability up to the inside of the coating film can be obtained. It is possible to prevent the line shape from being deteriorated due to the occurrence of undercut in the cured coating film. Moreover, by using the oxime ester compound represented by the above general formula, in particular, the sensitivity to each active energy ray at a wavelength of 365 nm and its vicinity, a wavelength of 385 nm and its vicinity, and a wavelength of 405 nm and its vicinity is improved. When the active energy ray of each wavelength is used, excellent photocurability up to the deep part of the coating film, that is, excellent sensitivity at the deep part of the coating film is obtained, and the resolution is improved.

Although a photoinitiator will not be specifically limited if it is an oxime ester compound of the said general formula, For example, it has the following chemical structure (9-ethyl-6-nitro-9H-carbazol-3-yl) (4- ( Mention may be made of (1-methoxypropan-2-yl) oxy) -2-methylphenyl) methanone O -acetyl oxime.

  The content of the oxime ester compound of the above general formula is not particularly limited. For example, the lower limit value is the exposure amount by the direct drawing apparatus with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin (solid content, hereinafter the same). Even if the exposure amount is the same as that of the batch exposure, 0.1 part by mass is preferable from the viewpoint of reliably preventing the deterioration of the line shape even in the coating film containing the colorant, and further improves the sensitivity and the line shape during development. In particular, 0.2 parts by mass is particularly preferable. On the other hand, the upper limit is preferably 4.0 parts by mass from the viewpoint of suppressing the occurrence of mist during heat treatment, for example, 100 parts by mass of the carboxyl group-containing photosensitive resin, and 2. 5 parts by mass is particularly preferred.

  In addition to the oxime ester compound of the above general formula, if necessary, another photopolymerization initiator may be further blended. Although it does not specifically limit as another photoinitiator, For example, a thioxanthone type photoinitiator can be mentioned. By blending the thioxanthone-based photopolymerization initiator, the line-shaped undercut may be reduced to further improve the resolution. The thioxanthone photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having a thioxanthone structure. For example, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone and the like.

  The content of the thioxanthone photopolymerization initiator is not particularly limited. For example, the lower limit is 0.05 parts by mass from the viewpoint that the resolution is reliably improved with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin. Is preferable, and 0.1 part by mass is particularly preferable. On the other hand, the upper limit is preferably 1.0 part by mass, particularly preferably 0.5 part by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, from the viewpoint of preventing line thickening.

  Examples of photopolymerization initiators other than thioxanthone photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2 , 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1 -[4- (Methylthio) phenyl] -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 4- (2-hydroxyethoxy) ) Phenyl- 2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-amino Anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, 1,2-octanedione and the like.

  The blending ratio (mass ratio) of the oxime ester compound of the above general formula and the other photopolymerization initiator in the case of blending other photopolymerization initiator is not particularly limited, but suppresses the generation of mist during the heat treatment. The oxime ester compound of the above general formula: other photopolymerization initiator = 1.0: 0.5 to 20 is preferable, and the oxime ester compound of the above general formula: Other photopolymerization initiators = 1.0: 1.0 to 10 are particularly preferable.

(C) Epoxy compound The epoxy compound is for increasing the crosslinking density of the cured product to obtain a cured product such as a cured coating film having sufficient mechanical strength. Examples of the epoxy compound include an epoxy resin. The structure of the epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin (biphenyl novolak type epoxy resin, phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, p-tert-butylphenol novolac type epoxy resin), bisphenol F type and bisphenol S type epoxy resin obtained by reacting bisphenol F and bisphenol S with epichlorohydrin, cyclohexene oxide group, tricyclodecane oxide group, cyclopentene oxide Group cycloaliphatic epoxy resin, dicyclopentadiene type epoxy resin, adamantane type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl group Alkyl type epoxy resins, biphenyl type epoxy resins and the like. These compounds may be used alone or in combination of two or more.

  The content of the epoxy compound is not particularly limited, but is 10 to 100 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of obtaining a cured coating film having sufficient mechanical strength without impairing flexibility. Is preferable, and 20-70 mass parts is especially preferable.

(D) Colorant The colorant is not particularly limited, such as a pigment or a dye, and any color such as a white colorant, a blue colorant, a yellow colorant, and a black colorant can be used. Examples of the colorant include inorganic colorants such as titanium oxide, which is a white colorant, and carbon black, which is a black colorant, and organic materials such as phthalocyanine-type, anthraquinone-type, such as phthalocyanine green, phthalocyanine blue, and lionol blue. Examples thereof include system colorants. These colorants may be used alone or in combination of two or more.

  Content of a coloring agent is not specifically limited, For example, 1-10 mass parts is preferable with respect to 100 mass parts of carboxyl group-containing photosensitive resin.

  In the photosensitive resin composition of the present invention, in addition to the components (A) to (D) described above, various additive components such as a reactive diluent, an antifoaming agent, an extender pigment, a difficult pigment, A flame retardant, a solvent, various additives, etc. can be contained suitably.

  The reactive diluent is, for example, a photopolymerizable monomer and a compound having at least one polymerizable double bond per molecule. The reactive diluent is used to obtain a cured product having sufficient acid resistance, heat resistance, alkali resistance, etc., by sufficiently photocuring the photosensitive resin composition.

  The reactive diluent is not particularly limited as long as it is the above compound. For example, 2-hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, 2-hydroxy-3- Phenoxypropyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl Glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxa De-modified phosphate di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tri (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  Although an antifoamer is not specifically limited, For example, a silicone type, a hydrocarbon type, an acrylic type etc. can be mentioned. The extender pigment is for increasing the strength and rigidity of the cured product, and examples thereof include barium sulfate, silica, alumina, aluminum hydroxide, talc, and mica.

  By mix | blending a flame retardant, a flame retardance can be provided to the hardened | cured material of the photosensitive resin composition of this invention. A flame retardant is not specifically limited, A well-known thing can be used. Examples of the flame retardant include phosphorus element-containing compounds. Specific examples of the phosphorus element-containing compound include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, tris (bromo). Halogenated phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate Esters; non-halogen aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; triphenyl phosphate Cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethylphenyl) phosphate, Tris (t-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate, octyl diphenyl phosphate, 3-glycidyloxypropylene diphenylphosphine oxide, 3-glycidyloxydiphenylphosphine oxide, diphenylvinylphosphine oxide, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphafena Non-halogens such as entolen-10-oxide, 2- (9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl) methylsuccinic acid bis- (2-hydroxyethyl) -ester polymer Aromatic phosphoric acid ester; aluminum trisdiethylphosphinate, aluminum diethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, Bisdiethylphosphinate titanyl, tetrakisdiethylphosphinate titanium, bismethylethylphosphinate titanyl, tetrakismethylethylphosphinate titanium, bisdiphenylphosphinate titani Cyclic or chain phosphazene compounds having a substituted or unsubstituted phenoxy group or a substituted or unsubstituted naphthoxy group, such as metal salts of phosphinic acids such as titanium tetrakisdiphenylphosphinate, cyclic phenoxyphosphazenes, and cyclic cyanophenoxyphosphazenes And triallylphosphine.

  The solvent (non-reactive diluent) is for adjusting the viscosity and drying property of the photosensitive resin composition. The solvent is not particularly limited. For example, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, and alicyclic such as cyclohexane and methylcyclohexane. Petroleum solvents such as hydrocarbons, petroleum ether, petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol Esters such as acetate, butyl carbitol acetate, ethyl diglycol acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate And the like can be given. These may be used alone or in combination of two or more.

  Various additives include urethane (meta) that contributes to imparting flexibility to latent curing agents such as dicyandiamide (DICY) and its derivatives, melamine and its derivatives, antioxidants, coupling agents, and cured products. ) Acrylate and the like.

  The method for producing the photosensitive resin composition of the present invention described above is not limited to a specific method. For example, after blending the above components at a predetermined ratio, at room temperature, a kneading means such as a three roll, ball mill, sand mill, or the like. Alternatively, it can be produced by kneading or mixing by a stirring means such as a super mixer or a planetary mixer. Further, prior to the kneading or mixing, if necessary, preliminary kneading or premixing may be performed.

  Next, the usage method of the above-mentioned photosensitive resin composition of this invention is demonstrated. Here, the case where the photosensitive resin composition of the present invention is applied as a solder resist film on a circuit board will be described as an example.

  The photosensitive resin composition of the present invention obtained as described above, for example, on a printed wiring board having a circuit pattern formed by etching a copper foil, screen printing, spray coater, bar coater, applicator, blade The coating is applied to a desired thickness using a known coating method such as a coater, knife coater, roll coater or gravure coater. After application, when a solvent (non-reactive diluent) is added to the photosensitive resin composition, the solvent in the photosensitive resin composition is volatilized at a temperature of about 60 to 80 ° C. for 15 to 60 minutes. A tack-free coating film is formed by preliminary drying with heating to a certain degree. Next, an active energy ray (for example, ultraviolet rays) is directly irradiated on the photosensitive resin composition according to a desired pattern using a direct drawing apparatus, and the coating film is photocured in the pattern. Next, the coating film is developed by removing non-exposed areas with a dilute alkaline aqueous solution. For example, a spray method, a shower method, or the like is used as the developing method, and examples of the dilute alkaline aqueous solution include a 0.5 to 5% by mass sodium carbonate aqueous solution. Next, the developed coating film is thermally cured by performing post-cure for 20 to 80 minutes with a hot air circulation dryer or the like at 130 to 170 ° C., and a cured coating film having a target pattern is printed on the printed wiring board. Can be formed on top.

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Examples 1-12, Comparative Examples 1-3
Each component shown in the following Table 1 is blended in the blending ratio shown in the following Table 1, mixed and dispersed at room temperature using three rolls, and used in Examples 1 to 12 and Comparative Examples 1 to 3. A functional resin composition was prepared. Unless otherwise indicated, the compounding amount of each component shown in Table 1 below indicates parts by mass, and the blank of the compounding amount means that the compounding is 0 part by mass.

In addition, the detail about each component in Table 1 is as follows.
(A) Carboxy group-containing photosensitive resin ZAR-2000: manufactured by Nippon Kayaku Co., Ltd. (solid content 65% by mass, diethylene glycol monoethyl ether acetate 25% by mass, solvent naphtha 10% by mass).
-FLX-2089: Nippon Kayaku Co., Ltd. (solid content 65 mass%, diethylene glycol monoethyl ether acetate 35 mass%).
-ZCR-1569H: Nippon Kayaku Co., Ltd. product (solid content 65 mass%, propylene glycol monomethyl ether acetate 35 mass%).

Synthetic resin A-1
In a 500 mL separable flask equipped with a stirrer and a reflux condenser, 86.45 g of diethylene glycol monoethyl ether acetate (hereinafter “EDGAC”), 8-ethyloctadecanedioic acid (Okamura Oil Co., Ltd.) in a nitrogen / air (2: 1) atmosphere. SB-20 (26.54 g, 6.3 parts by mass), behenic acid 45.35 g (10.7 parts by mass), stearic acid 9.71 g (2.3 parts by mass), and acrylic acid 14.4 g. 36 g (3.4 parts by mass), 0.65 g (0.1 parts by mass) of triphenylphosphine (TPP), and 0.43 g (0.1 parts by mass) of methoxyhydroquinone (MEHQ) were charged. While blowing air (2: 1) at 0.3 mL / sec, the mixture was heated and stirred until dissolved at 110 ° C. Separately, 137.65 g (32.6 parts by mass) of biphenylaralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent of 265 to 285 g / eq) was heated to 80 ° C. in 59.8 g of EDGAC solvent. Then, the solution was uniformly dissolved and charged into the flask, heated and stirred at 115 ° C. for 15 to 17 hours, and reacted until the acid value of the reaction solution became 6 mgKOH / g or less. To this reaction product, 42.23 g (9.9 parts by mass) of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTAn) was added and stirred at 100 ° C. for 2 to 3 hours in an air atmosphere. The disappearance of the acid anhydride was confirmed by FT-IR (infrared spectrophotometer). As a result, a synthetic resin A-1 having a solid content of 65% by mass and an acid value of 85 mgKOH / g shown in Table 1 was obtained.

(B) Photopolymerization initiator, NCI-831: manufactured by ADEKA.

(C) Epoxy compound / EPICRON 860: manufactured by DIC Corporation.

(D) Colorant / Denka Black: manufactured by Denki Kagaku Kogyo Co., Ltd.
-Lionol Blue FG-7351: manufactured by Toyo Ink Manufacturing Co., Ltd.

(B) Photopolymerization initiator other than the component OXE-02, Irgacure 369, Irgacure 907: manufactured by BASF Corporation.
* ChemcureDETX: manufactured by Nippon Shibel Hegner.
Additive • EBECRYL 8405: manufactured by Daicel Ornex Co., Ltd.
Extender pigment, Heidilite H-42STV: manufactured by Showa Denko K.K.
Solvent, diethylene glycol monoethyl ether acetate: manufactured by Sanyo Chemicals.
Antifoaming agent, KS-66: manufactured by Shin-Etsu Chemical Co., Ltd.
Flame retardant Exolit OP-935: manufactured by Clariant Japan.

Test piece preparation process After the surface treatment of the substrate (glass epoxy substrate, “FR4”, Cu thickness 25 μm) with dilute sulfuric acid (5 mass%), the screen printing method and the examples prepared as described above and comparative examples Each photosensitive resin composition was applied. After coating, preliminary drying was performed at 80 ° C. for 20 minutes in a BOX furnace. After preliminary drying, a predetermined amount of active energy rays having a predetermined wavelength shown in the following Table 2 were exposed on the coating film under the exposure conditions of the direct drawing exposure machines 1 to 3 shown in the following Table 2. After the exposure, development was performed using a 1% by mass aqueous sodium carbonate solution at a development temperature of 30 ° C. and a development pressure of 0.2 MPa. After development, a cured coating film was formed on the substrate by post-curing at 150 ° C. for 60 minutes in a BOX furnace. The thickness of the cured coating film was 20-23 μm.

Evaluation (1) Sensitivity Stepped tablets for sensitivity measurement (21 steps made by Kodak Co., Ltd.) are adhered to the coating film on the substrate that has been subjected to the preliminary drying step of the above-described test piece preparation step. What was irradiated on the exposure conditions of the direct drawing exposure machines 1-3 shown was made into the test piece. The test piece was developed in the same manner as in the test piece preparation step. The maximum number of stages with 100% remaining sensitivity after development was evaluated as sensitivity. The larger the number of steps, the better the sensitivity.

(2) Resolution The photosensitive resin composition was prepared according to the above test piece preparation step except that the photomask was exposed using a photomask having a pattern with a line width of 30 μm to 200 μm and the thickness of the cured coating film was 40 μm. Coated. About the produced cured coating film, the thinnest line width (micrometer) remaining on a board | substrate with a perfect shape as a line was observed visually, and it evaluated as resolution.

(3) Electrical insulation The substrate is changed to a comb-shaped test pattern (line width 100 μm, line spacing 100 μm, glass epoxy substrate (plate thickness 1.6 mm, conductor thickness 18 μm)), and photosensitive according to the above test piece preparation process. The resin composition was applied to form a cured coating film. The obtained test piece was applied in a tank of 85 ° C. and 85% humidity and left to stand for 1000 hours by applying a direct current of 50 V. Then, the test piece was taken out of the tank and insulated with HIGH RESISTANCE METER (manufactured by Agilent). A resistance value (unit: Ω) was measured to evaluate electrical insulation.

  The evaluation results are shown in Table 3 below.

From Examples 1 to 12 in Table 3, as the photopolymerization initiator, (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1- with methoxypropan-2-yl) oxy) -2-methylphenyl) methanone O- acetyl Oki Sum, even exposure in direct drawing exposure machine with an exposure amount 50~100mJ / cm ^2, an electrically insulating Without loss, the sensitivity was improved to four or more stages, and even with a thin line width of 30 to 60 μm, a perfectly shaped line could be obtained. Also, from Examples 1, 2, 5, 6, and 7, (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropan-2-yl) oxy) -2 -Methylphenyl) methanone When O-acetyl oxime is contained in an amount of about 0.5 parts by mass with respect to 100 parts by mass (solid content) of the carboxyl group-containing photosensitive resin, it is compared with Example 3 containing about 0.2 parts by mass. As a result, the sensitivity was further improved, and the same or better resolution was obtained. In particular, in the exposure consisting of active energy rays with wavelengths of 365 nm, 385 nm and 405 nm and the exposure consisting of active energy rays with wavelengths of 375 nm and 405 nm, the resolution was further improved. Also, from Examples 4 and 12, (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropan-2-yl) oxy) -2-methylphenyl) methanone O -When acetyl oxime contains about 2.0 mass parts with respect to 100 mass parts (solid content) of carboxyl group-containing photosensitive resin, compared with another Example, the further outstanding sensitivity and resolution will be. Obtained.

  Further, from the comparison of Example 1 and Example 8, Example 5 and Example 9, Example 6 and Example 10, Example 7 and Example 11, (9-ethyl-6-nitro-9H-carbazole- 3-yl) (4-((1-methoxypropan-2-yl) oxy) -2-methylphenyl) methanone O-acetyl oxime is based on 100 parts by mass (solid content) of a carboxyl group-containing photosensitive resin. When about 0.5 parts by mass is contained, the sensitivity equivalent to that when a photopolymerization initiator other than the component (B) is further blended can be obtained without further blending a photopolymerization initiator other than the component (B). It was. Further, from comparison between Example 4 and Example 12, (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropan-2-yl) oxy) -2-methyl When phenyl) methanone O-acetyl oxime contains about 2.0 parts by mass with respect to 100 parts by mass (solid content) of the carboxyl group-containing photosensitive resin, a photopolymerization initiator other than the component (B) is further blended. Even without this, the same sensitivity and resolution as when a photopolymerization initiator other than the component (B) was further blended were obtained.

Further, from Table 3, in exposure composed of active energy rays with wavelengths of 365 nm, 385 nm, and 405 nm, even if the exposure dose is reduced to 50 mJ / cm ² , the exposure dose with active energy rays of other wavelengths is 70 to 100 mJ / cm ² Sensitivity and resolution equivalent to or better than the above were obtained. Therefore, it has been found that the use of active energy rays having wavelengths of 365 nm, 385 nm, and 405 nm further improves productivity.

  On the other hand, from Comparative Examples 2 and 3, when using an oxime ester photopolymerization initiator having one carbazole skeleton in one molecule, which is not a compound represented by the above general formula, the resolution is as thin as 80 μm or more. With the line width, a complete line could not be obtained. Further, from Comparative Example 1, when the photopolymerization initiator represented by the above general formula was not blended, the sensitivity was 1 step or less, the resolution was 200 μm or more, and neither sensitivity nor resolution was obtained.

  In the photosensitive resin composition of the present invention, the photopolymerization reaction of the coating film is promoted more than before, and more sufficient photocuring can be obtained up to the deep part of the coating film. High utility value in the field of photocuring films.

Claims (4)

(A) a photosensitive resin composition for direct exposure comprising a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, and (D) a colorant,
The (B) photopolymerization initiator has the following general formula

(In the formula, R ₁ represents hydrogen, an alkyl group having 1 to 17 carbon atoms or an alkoxy group having 1 to 17 carbon atoms, R ₂ represents a phenyl group or an alkyl group having 1 to 5 carbon atoms, —O— represents C _m H _2m -CH ₃ and _{-O-C n H 2n -O-} C p H 2p least one substituted phenyl group substituted with a group selected from the group consisting of -CH _3, m is 0 or An integer of 1 to 5, n is an integer of 1 to 5, p is 0 or an integer of 1 to 5).
The photosensitive resin composition for direct drawing exposure, wherein the colorant (D) contains carbon black and a phthalocyanine compound .   The photopolymerization initiator (B) is (9-ethyl-6-nitro-9H-carbazol-3-yl) (4-((1-methoxypropan-2-yl) oxy) -2-methylphenyl) methanone. It is O-acetyl oxime, The photosensitive resin composition for direct drawing exposure of Claim 1 characterized by the above-mentioned.   The said (B) photoinitiator contains 0.1-2.5 mass parts with respect to 100 mass parts of said (A) carboxyl group-containing photosensitive resin, The Claim 1 or 2 characterized by the above-mentioned. Photosensitive resin composition for direct drawing exposure.   The printed wiring board which has a photocuring film of the photosensitive resin composition for direct drawing exposure of any one of Claims 1 thru | or 3.