KR20150106837A - Photosensitive resin composition - Google Patents

Abstract

The purpose of the present invention is to provide a photosensitive resin composition which does not damage basic characteristics such as adhesiveness to a circuit pattern or electric insulation and prevents deterioration of a line shape even if the exposure quantity by a direct drawing device is the same level as the exposure quantity of one shot exposure. The present invention provides the photosensitive resin composition including: (A) a photosensitive resin containing a carboxyl group, (B) a photopolymerization initiator, (C) an epoxy compound, and (D) a colorant, wherein (B) the photopolymerization initiator is an oxime ester compound having two or more carbazole frames in one molecule.

Description

[0001] PHOTOSENSITIVE RESIN COMPOSITION [0002]

The present invention relates to a wiring substrate such as a photosensitive resin composition suitable for a covering material for covering a conductor circuit pattern formed on a substrate such as a printed wiring board and a printed wiring board coated with a cured product thereof .

When a solder-resist film is formed on a printed wiring board, a photomask is conventionally provided on a coating film of a printed wiring board and an exposure process is performed by a batch exposure method in which the entire surface of the printed wiring board is exposed. However, recently, when exposure of a photosensitive resin composition coated on a printed wiring board, exposure by a CNC apparatus that draws an image directly using CAD data has received attention.

In the conventional photosensitive resin composition used for batch exposure, an? -Aminoalkylphenone-based photopolymerization initiator (Patent Document 1) and an acylphosphine oxide photopolymerization initiator (Patent Document 2) have been used as a photopolymerization initiator.

However, the photopolymerization reaction hardly progresses in the interior of the coating film due to the damage caused by the oxygen molecules in the exposure in the direct exposure. Further, when a coloring agent is blended in the photosensitive resin composition, the photopolymerization reaction is more difficult to proceed inside the coating film because the hiding power of the coating film is increased. As a result, sufficient photo-curing can not be obtained at the deep part of the coating film, and undercutting occurs in the cured coating film, which deteriorates the line shape. In addition, since the line shape is deteriorated, it can not cope with a circuit pattern having a fine pitch. In some cases, there is a problem that a line is peeled off or a defect occurs. Further, when the colorant is mixed, the above problem becomes more remarkable. In order to cope with this problem of line shape deterioration, it is necessary to increase the exposure amount in the photo-curing step, rather than the batch exposure, so that the photo-curing is sufficiently performed even at the deep part of the coating film. However, there has been a problem that increasing the exposure dose hinders the improvement of the production efficiency.

Japanese Patent Application Laid-Open No. 2010-276859 Japanese Patent Application Laid-Open No. 2011-232402

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the deterioration of the line shape even if the exposure amount by the machine tool is the same as the exposure amount of the batch exposure without impairing the basic characteristics such as adhesion with the circuit pattern and electrical insulation, And to provide a photosensitive resin composition.

An embodiment 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, wherein the photopolymerization initiator (B) Is an oxime ester compound having at least two carbazole skeletons.

In the present invention, the photopolymerization initiator (B)

(Wherein R ¹ represents a single bond or alkylene having 1 to 10 carbon atoms, R ² and R ^{2 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 17 carbon atoms, or a halogen group , R ³ and R ^{3 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms or an alkoxy group having 1 to 17 carbon atoms.

As the photopolymerization initiator (B), an oxime ester compound having two or more carbazole structures in one molecule having a nitro group is more preferably used.

In an embodiment of the present invention, the photopolymerization initiator (B) is 1,8-octanedione, 1,8-bis [9-ethyl- (O-acetyloxime) or 1,8-octanedione, 1,8-bis [9- (2-ethylhexyl) -6- O-acetyloxime). ≪ / RTI >

An embodiment of the present invention is a photosensitive resin composition characterized by further comprising (B) a thioxanthene photopolymerization initiator in addition to the photopolymerization initiator (B) as the photopolymerization initiator.

An embodiment of the present invention is a photosensitive resin composition, wherein the photopolymerization initiator (B) is contained in an amount of 0.1 to 4.0 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin (A).

An embodiment of the present invention is a printed wiring board having a cured film obtained by photo-curing the photosensitive resin composition.

According to the aspect of the present invention, by using an oxime ester compound having two or more carbazole skeletons in one molecule (oxime ester-based photopolymerization initiator having two or more carbazole skeletons in one molecule) as a photopolymerization initiator, Even if the amount of exposure by the photomask is about the same as the exposure amount of the batch exposure for exposing the entire surface of the printed wiring board, the cured coating film is sufficiently cured to the deep part of the coating film without damaging the adhesion to the circuit pattern of the circuit pattern, Therefore, it is possible to prevent an undercut from occurring in the cured coating film and deteriorate the line shape. Further, deterioration of the line shape of the cured coating film can be prevented even with exposure by the machine tool apparatus, so that even a circuit pattern with a fine pitch can prevent the line from being peeled off or being defective. Further, since the amount of exposure by the machine tool can be made to be the same as the amount of exposure by the batch exposure, the exposure step of the machine tool can be shortened, and the production efficiency is further improved.

According to the form of the present invention, the use of an oxime ester compound having two or more carbazole skeletons in one molecule represented by the general formula (I) as the photopolymerization initiator further improves the photocurability to the core of the coating film.

According to an aspect of the present invention, oxime ester compounds having two or more carbazole skeletons in one molecule represented by the above general formula (I) include 1,8-octanedione, 1,8-bis [9- 6-nitro-9H-carbazol-3-yl] -, 1,8-bis (O-acetyloxime) or 1,8- -Nitro-9H-carbazol-3-yl] -, 1,8-bis (O-acetyloxime) is used, the photocurability to the core of the coating film is further improved.

According to the aspect of the present invention, sensitivity of the photosensitive resin composition to ultraviolet rays is further improved by using a photochemical polymerization initiation system in addition to an oxime ester compound having two or more carbazole skeletons in one molecule as a photopolymerization initiator .

According to the aspect of the present invention, since the photopolymerization initiator is contained in an amount of 0.1 to 4.0 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, the sensitivity to ultraviolet rays is reliably improved. Therefore, It is possible to reliably prevent deterioration of the line shape of the cured coating film.

Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition 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, wherein the photopolymerization initiator (B) It is an oxime ester compound having two or more carbazole skeletons in a molecule.

(A) a carboxyl group-containing photosensitive resin

The carboxyl group-containing photosensitive resin is not particularly limited, and for example, a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond can be mentioned. Examples of the carboxyl group-containing photosensitive resin include acrylic resins such as acrylic acid and methacrylic acid (hereinafter sometimes referred to as " (meth) acrylic acid ") at least a part of epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups in one molecule Obtained by reacting a radical polymerizable unsaturated monocarboxylic acid with a radical polymerizable unsaturated monocarboxylic acid to obtain a radical polymerizable unsaturated monocarboxylic epoxy resin such as epoxy (meth) acrylate and further reacting the produced hydroxyl group with a polybasic acid or an anhydride thereof, And polybasic acid-modified radical-polymerizable unsaturated monocarboxylic epoxy resins such as (meth) acrylate.

The polyfunctional epoxy resin may be any epoxy resin having two or more functional groups. The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, but it is preferably 1000 or less, and particularly preferably 100 to 500. Examples of the polyfunctional epoxy resin include rubber-modified epoxy resins such as biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin and silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A Phenol novolak type epoxy resins such as bisphenol F type and bisphenol AD type, cresol novolak type epoxy resins such as o-cresol novolak type, bisphenol A novolak type epoxy resins, cyclic aliphatic polyfunctional epoxy resins, Polycyclic epoxy resins, bisphenol-modified novolak-type epoxy resins, polyfunctional modified novolak-type epoxy resins, aromatic compounds having a phenolic hydroxyl group and a phenolic hydroxyl group And condensation type epoxy resin of aldehyde. Further, halogen atoms such as Br and Cl may be introduced into these resins. These epoxy resins may be used alone or in combination of two or more.

The radical polymerizable unsaturated monocarboxylic acid is not particularly limited and includes, for example, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like, and acrylic acid and methacrylic acid are preferable. The method of reacting the epoxy resin with 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 a suitable diluent.

The polybasic acid and the polybasic acid anhydride react with the hydroxyl group formed by the reaction of the epoxy resin with the radical polymerizable unsaturated monocarboxylic acid to thereby introduce a free carboxyl group into the resin. The polybasic acid or its anhydride is not particularly limited, and both saturated and unsaturated can be used. Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3- ethyltetrahydrophthalic acid, There may be mentioned phthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, Methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid, and examples of polybasic acid anhydrides include anhydrides thereof. These compounds may be used alone or in admixture of two or more.

The above-mentioned polybasic acid-modified unsaturated monocarboxylic epoxy resin can also be used as a carboxyl-containing photosensitive resin. If necessary, the polybasic acid-modified unsaturated monocarboxylic epoxy resin may contain at least one radically polymerizable unsaturated group and an epoxy group in the carboxyl group of the polybasic acid- It is also possible to introduce a radical polymerizable unsaturated group by reacting a glycidyl compound to obtain a photosensitive resin containing a carboxyl group which further improves photosensitivity.

In the carboxyl group-containing photosensitive resin with further improved photosensitivity, the radically polymerizable unsaturated group is bonded to the side chain of the polybasic acid-modified unsaturated monocarboxylic epoxy resin by the reaction of the glycidyl compound, And becomes a resin capable of having photosensitive characteristics. Examples of the compound having at least one radically polymerizable unsaturated group and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, and the like. . In addition, a glycidyl group may be contained in plural molecules in one molecule. The above-mentioned compounds having at least one radically polymerizable unsaturated group and an epoxy group may be used alone or in admixture of two or more.

The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit value thereof is preferably 30 mgKOH / g, more preferably 40 mgKOH / g, from the viewpoint of reliable alkali development. On the other hand, the upper limit of the acid value is preferably 200 mgKOH / g in view of prevention of dissolution of the exposed portion by the alkali developing solution, and particularly preferably 150 mgKOH / g from the viewpoints of moisture resistance of the cured product and deterioration of electrical characteristics.

The weight average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit value thereof is preferably 3000 in view of the toughness of the cured product and the tack-and-dry property, and particularly preferably 5000. On the other hand, the upper limit value of the mass average molecular weight is preferably 200,000, more preferably 50,000, from the viewpoint of smooth alkaline developability.

ZCR-1601H, ZAR-2000, ZFR-1122, FLX-2089 (trade name) manufactured by Daicel Allyn Co., (Manufactured by Nippon Kayaku Co., Ltd.) and Lipoxy SP-4621 (manufactured by Showa Kobunshi Co., Ltd.). These resins may be used alone or in combination of two or more.

(B) a photopolymerization initiator

In the photosensitive resin composition of the present invention, an oxime ester compound having two or more carbazole skeletons in one molecule is used as a photopolymerization initiator. The use of an oxime ester compound having two or more carbazole skeletons in one molecule improves the sensitivity of the coating film and sufficiently cures the coating film to the deep portion even when the exposure amount in the apparatus is approximately the same as the exposure amount of the batch exposure , It is possible to prevent the line shape from deteriorating in the development after the exposure process. This is because the oxime ester compound having two or more carbazole skeletons in one molecule has a wavelength range (300 to 400 mu m) wider than the wavelength region (320 to 370 mu m) of the photopolymerization initiator used in exposure by the conventional apparatus It is considered to be related to having an absorption characteristic.

The chemical structure of the oxime ester compound is not particularly limited as long as it is an oxime ester compound having two or more carbazole structures in one molecule.

(Wherein R ¹ represents a single bond or alkylene having 1 to 10 carbon atoms, R ² and R ^{2 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 17 carbon atoms, or a halogen group , R ³ and R ^{3 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms, or an alkoxy group having 1 to 17 carbon atoms), an oxime ester compound having two carbazole skeletons and two oxime esters in one molecule .

Of the oxime ester compounds having two or more carbazole skeletons in one molecule, an oxime ester compound having two or more carbazole structures in one molecule having a nitro group is more preferably used. As described above, the oxime ester compound having a nitro group introduced into the carbazole structure can make its effective absorption region (wavelength region) longer wavelength, and its optical sensitivity can be further improved.

Examples of such oxime ester compounds of formula (I) include 1,8-octanedione, 1,8-bis [9-ethyl-6-nitro-9H- 3-yl] -, 1,8-bis (O-acetyloxime), 1,8-octanedione represented by the following formula (B- -Nitro-9H-carbazol-3-yl] -, 1,8-bis (O-acetyloxime).

The content of the oxime ester compound having two or more carbazole skeletons in one molecule is not particularly limited. For example, the lower limit of the content is the same as the exposure amount of the batch exposure with respect to 100 parts by mass of the carboxyl group- , The amount is preferably 0.1 part by mass in view of reliably preventing deterioration of the line shape even in a coating film containing a coloring agent, and particularly preferably 0.2 parts by mass in view of further improving the sensitivity and line shape upon development. On the other hand, the upper limit value thereof is preferably 4.0 parts by mass, for example, from the viewpoint of reducing the outgas from the coating film to 100 parts by mass of the carboxyl group-containing photosensitive resin, and particularly preferably 3.0 parts by mass in terms of dimensional accuracy of the line.

In addition to the above oxime ester compound having two or more carbazole skeletons in one molecule, sensitivity to ultraviolet rays can be further improved by further blending a thioxanthone photopolymerization initiator. The thioxanthone photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having a thioxanthone structure, and examples thereof include 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, Dimethyl thioxanthone, and 2,4-diethyl thioxanthone.

The content of the thioxanthene photopolymerization initiator is not particularly limited. For example, the lower limit of the content is preferably 0.3 part by mass, more preferably 0.6 part by mass, in view of improving the sensitivity to ultraviolet light to 100 parts by mass of the carboxyl group- Particularly preferred. On the other hand, the upper limit value thereof is preferably 4.0 parts by mass, particularly preferably 3.0 parts by mass, from the viewpoint of reducing the undercut of the line shape, for example, with respect to 100 parts by mass of the photosensitive resin containing a carboxyl group.

(C) an epoxy compound

The epoxy compound is intended to obtain a cured product such as a cured coating film having a sufficient mechanical strength by increasing the cross-linking density of the cured product. As the epoxy compound, for example, an epoxy resin can be mentioned. The structure of the epoxy resin is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin (biphenyl novolak type epoxy resin, phenol novolac type epoxy resin, o-cresol novolak Butylphenol novolac epoxy resin), bisphenol F or bisphenol S obtained by reacting bisphenol S with epichlorohydrin, an epoxy resin of bisphenol F type or bisphenol S type, and furthermore, a cyclohexene oxide group , Tricyclodecane oxide group, cyclopentaneoxide group and the like, dicyclopentadiene-type epoxy resin, and adamantane-type epoxy resin. These compounds may be used alone or in admixture of two or more.

The content of the epoxy compound is not particularly limited, but is preferably 10 to 100 parts by mass, more preferably 20 to 70 parts by mass, relative to 100 parts by mass of the carboxyl group-containing photosensitive resin, from the viewpoint of obtaining a cured coating film of sufficient mechanical strength without impairing flexibility Do.

(D) Colorant

The colorant is not particularly limited, such as a pigment and a dye, and a white colorant, a blue colorant, a yellow colorant, a black colorant and the like can be used. Examples of the colorant include inorganic coloring agents such as titanium oxide as a white coloring agent and carbon black as a black coloring agent and organic coloring agents such as phthalocyanine and anthraquinone as phthalocyanine green, phthalocyanine blue and rionol blue have. These coloring agents may be used alone or in combination of two or more.

The content of the colorant is not particularly limited and is, for example, 1 to 10 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin.

In addition to the components (A) to (D) described above, the photosensitive resin composition of the present invention may suitably contain various additive components as required, for example, a reactive diluent, defoaming agent, extender pigment, various additives and solvents.

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

The reactive diluent is not particularly limited as long as the compound is the above-mentioned compound, and examples thereof include 2-hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (Meth) acrylate, trimethylolpropane tri (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene oxide modified di (meth) acrylate, allyl cyclohexyl di (meth) acrylate, isocyanurate di (Meth) acrylates such as methylol propane tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane tri (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.

The content of the reactive diluent is not particularly limited and is preferably 2.0 to 500 parts by mass, more preferably 10 to 300 parts by mass, based on 100 parts by mass of the carboxyl group-containing photosensitive resin.

The extender pigment is for increasing the strength and rigidity of the cured product, and examples thereof include barium sulfate, silica, alumina, talc, mica and the like. The defoaming agent is not particularly limited, and examples thereof include a silicone type, a hydrocarbon type, and an acrylic type. Examples of the various additives include latent curing agents such as dicyandiamide (DICY) and derivatives thereof, melamine and derivatives thereof, antioxidants, and coupling agents.

The solvent (non-reactive diluent) is for controlling the viscosity or dryness of the photosensitive resin composition. Examples of the solvent include, but are not limited to, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, alcohols such as cyclohexane and methylcyclohexane Petroleum solvents such as aliphatic hydrocarbons, petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carvitol such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve, And esters such as acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, ethyl diglycol acetate, diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate. These may be used alone or in combination of two or more.

The method of producing the photosensitive resin composition of the present invention is not limited to a specific method. For example, the components may be blended in a predetermined ratio and then kneaded at room temperature by a kneading means such as a triaxial roll, a ball mill, A kneader, a planetary mixer, or the like. Prior to the kneading or mixing, preliminary kneading or premixing may be carried out if necessary.

Next, a method of using the above-mentioned photosensitive resin composition of the present invention will be described. Here, the case where the photosensitive resin composition of the present invention is coated as a solder resist film on a circuit substrate will be described as an example.

The photosensitive resin composition of the present invention thus obtained is applied to a printed wiring board having a circuit pattern formed by etching a copper foil, for example, by screen printing, spray coater, bar coater, applicator, blade coater, knife coater, roll coater, Using a known coating method such as a gravure coater. When the solvent is mixed in the photosensitive resin composition after the application, preliminary drying is performed by heating at a temperature of about 60 to 80 DEG C for about 15 to 60 minutes in order to volatilize the solvent (nonreactive diluent) in the photosensitive resin composition, Free coating film. Subsequently, an active energy ray (for example, ultraviolet rays) is directly irradiated onto the photosensitive resin composition in a desired manner in a homothetic apparatus to photo-cure the coating film on the pattern. Subsequently, the coating film is developed by removing the non-exposed region with a dilute aqueous alkali solution. As the developing method, for example, a spray method, a shower method, or the like is used, and as the dilute alkali aqueous solution, for example, an aqueous solution of sodium carbonate of 0.5 to 5 mass% can be used. Subsequently, curing is performed for 20 to 80 minutes in a hot air circulation type dryer at 130 to 170 DEG C to thermally cure the developed coating film, thereby forming a cured coating film having a desired pattern on the printed wiring board.

[Example]

EXAMPLES Next, examples of the present invention will be described, but the present invention is not limited to these examples unless the scope of the present invention is exceeded.

Examples 1 to 9 and Comparative Examples 1 to 5

The components shown in the following Table 1 were blended in the mixing ratios shown in Table 1 below and mixed and dispersed at room temperature using a three-roll mill to prepare the photosensitive resin compositions used in Examples 1 to 9 and Comparative Examples 1 to 5 Respectively. The amount of each component shown in the following Table 1 indicates a part by mass unless otherwise specified, and the amount of the compounded amount means that the compounding amount is 0 part by mass.

Details of each component in Table 1 are as follows.

(A) a carboxyl group-containing photosensitive resin

Cycroma P (ACA) Z-251: manufactured by Daicel Allynx Co., Ltd.

ZCR-1601H: manufactured by Nippon Kayaku Co., Ltd.

· ZAR-2000: manufactured by Nippon Kayaku Co., Ltd.

(B) an oxime ester-based photopolymerization initiator having two or more carbazole skeletons in one molecule

NCI-831: manufactured by Asahi Denka Co., Ltd.

(C) an epoxy compound

EP828: manufactured by Mitsubishi Chemical Corporation.

· N770: manufactured by DIC.

NC-3000: manufactured by Nippon Kayaku Co., Ltd.

(D) Colorant

Carbon black: manufactured by Mitsubishi Chemical Corporation.

Lionol Blue FG-7351: manufactured by Toyo Ink Manufacturing Co., Ltd.

Other photopolymerization initiators

Diethylthioxanthone: manufactured by Nippon Kayaku Co., Ltd.

OXE-02: manufactured by BASF.

Irgacure 369: Manufactured by BASF.

Reactive diluent

· M600: manufactured by Miwon (MIWON).

Defoamer

X-50-1095C: manufactured by Shin-Etsu Silicone Co., Ltd.

Extender pigment

· B-30: made by SAKAI KAGAKU CO., LTD.

solvent

Diethylene glycol monoethyl ether acetate: manufactured by Daicel Allynx Co., Ltd.

Test piece production process

(Cu thickness: 12.5 占 퐉, polyimide thickness: 25 占 퐉) of a polyimide film (manufactured by Shin-Nittsu Sumitomo Chemical Co., Ltd., "ESPANEX" After the substrates were surface-treated with dilute sulfuric acid (5 mass%), the photosensitive resin compositions of Examples 1 to 9 and Comparative Examples 1 to 5 prepared as described above were respectively applied by screen printing. After the application, preliminary drying was performed in a BOX furnace at 80 DEG C for 20 minutes. After the preliminary drying, ultraviolet rays of 250 to 450 nm in wavelength were exposed to the coating film by 250 mJ / cm ² using an exposure apparatus ("DilMPACT Mms60" manufactured by Orc Corporation). After the exposure, a 1% by mass aqueous solution of sodium carbonate was used for development at a developing pressure of 30 占 폚 and a developing pressure of 0.2 MPa. After development, curing was performed in a BOX furnace at 150 캜 for 60 minutes to form a cured coating film on the wiring board. The thickness of the cured coating film was 20 to 23 탆.

evaluation

(1) Sensitivity

A step tablet for sensitivity measurement (14 steps from Kodak Co., Ltd.) was brought into close contact with the coating film on the wiring board which had been subjected to the preliminary drying step of the above-mentioned test piece manufacturing step, and this was passed through the step tablet to use "DilMPACTMms60" And irradiated with ultraviolet light (wavelength: 250 to 450 nm) to 250 mJ / cm ² was used as a test piece. This test piece was subjected to development in the same manner as in the test piece production process. The maximum number of stages in which the number of stages of sensitivity after development remained 100% was evaluated as the sensitivity. The larger the number, the better the sensitivity.

(2) Line residue (占 퐉)

A polyimide film (substrate) was changed from Espanex to Capton 100H (25 mu m thick) manufactured by Toray DuPont Co., and a photomask having a pattern with a line width of 30 mu m to 150 mu m was used, , The photosensitive resin composition was applied to the cured coating film and the thinnest line width (mu m) remaining on the substrate in a complete shape as a line was visually observed and evaluated as line residue.

(3) Adhesion

The cured coating film of the test piece produced in the test piece production step was evaluated for adhesion to copper according to JIS K 5400.

(4) Electrical insulation

The substrate was changed from Espinex to a comb-shaped test pattern (line width of 100 m, line spacing of 100 m, glass epoxy substrate (plate thickness 1.6 mm, conductor thickness 18 m)), coating the photosensitive resin composition in accordance with the above- To form a cured coating film. The obtained test piece was subjected to direct current of 50 V in a tank at a temperature of 85 캜 and a humidity of 85% and allowed to stand for 1000 hours. Thereafter, the test piece was taken out of the tank, and a high resistance meter (HP4339A, manufactured by Hewlett Packard Co., ), And the electrical insulation property was evaluated.

The evaluation results are shown in Table 2 below.

From Examples 1 to 9 of Table 2, it was found that when an oxime ester compound having two or more carbazole skeletons in one molecule was used as the photopolymerization initiator, the exposure dose was 250 mJ / cm ² , which is a smaller amount of exposure than the batch exposure (usually 400 to 600 mJ / cm ² ) ² , the sensitivity was improved without impairing the adhesion and the electrical insulation, and a complete line could be obtained even if the line residue was 60 to 70 mu m in line width. Further, it is understood from Examples 1 and 2 that when an oxime ester photopolymerization initiator having two or more carbazole skeletons in one molecule is contained in an amount of 2 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, two or more carbazole skeletons Was contained in an amount of 0.2 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, the sensitivity and line residue were further improved as compared with the case where 0.2 parts by mass of the oxime ester-based photopolymerization initiator. Further, from Examples 8 and 9, the sensitivity was further improved by further using a thioxanthene photopolymerization initiator.

On the other hand, from Comparative Examples 1 to 5, when a photopolymerization initiator other than the oxime ester-based photopolymerization initiator having two or more carbazole skeletons in one molecule was used, good sensitivity could not be obtained. On the other hand, A complete shape line could not be obtained. This is also true for the oxime ester-based photopolymerization initiators (Comparative Examples 1, 2, 4, and 5) having one carbazole skeleton per molecule.

The photosensitive resin composition of the present invention has a higher value in the field of photocuring the coating film by, for example, direct exposure, since the photopolymerization reaction of the coating film is promoted more easily than that of the conventional method.

Claims (9)

A photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, and (D)
Wherein the photopolymerization initiator (B) is an oxime ester compound having two or more carbazole skeletons in one molecule. The photopolymerization initiator according to claim 1, wherein the photopolymerization initiator (B)

(Wherein R ¹ represents a single bond or alkylene having 1 to 10 carbon atoms, R ² and R ^{2 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 17 carbon atoms, or a halogen group , R ³ and R ^{3 '} each independently represent hydrogen, an alkyl group having 1 to 17 carbon atoms or an alkoxy group having 1 to 17 carbon atoms. The photopolymerization initiator according to claim 1 or 2, wherein the photopolymerization initiator (B) is 1,8-octanedione, 1,8-bis [9-ethyl-6-nitro- , 8-bis (O-acetyloxime) or 1,8-octanedione, 1,8-bis [9- 8-bis (O-acetyl oxime). The photosensitive resin composition according to claim 1 or 2, further comprising (B) a thioxanthene photopolymerization initiator in addition to the photopolymerization initiator (B) as the photopolymerization initiator. The photosensitive resin composition according to claim 3, wherein the photopolymerization initiator further comprises (B) a thioxanthene photopolymerization initiator in addition to the photopolymerization initiator (B). The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerization initiator (B) is contained in an amount of 0.1 to 4.0 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin (A). The photosensitive resin composition according to claim 3, wherein the photopolymerization initiator (B) is contained in an amount of 0.1 to 4.0 parts by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin (A). A printed wiring board having a cured film obtained by photo-curing the photosensitive resin composition according to any one of claims 1 to 3. A printed wiring board having a cured film obtained by photo-curing the photosensitive resin composition according to claim 3.