WO2014024804A1

WO2014024804A1 - Photosensitive resin composition for permanent mask resist, photosensitive element, method for forming resist pattern, and method for producing printed wiring board

Info

Publication number: WO2014024804A1
Application number: PCT/JP2013/071060
Authority: WO
Inventors: 華子頼; 絵美子太田; 泰治村上; 名越　俊昌; 田中　恵生
Original assignee: 日立化成株式会社
Priority date: 2012-08-06
Filing date: 2013-08-02
Publication date: 2014-02-13
Also published as: CN104520768A; KR20150042775A; TW201418882A; TWI589993B; JPWO2014024804A1

Abstract

The present invention provides a photosensitive resin composition for a permanent mask resist, the resin composition containing (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerization initiator and (C) a nitroxyl compound. The nitroxyl compound (C) contains a compound having a specific structure.

Description

Photosensitive resin composition for permanent mask resist, photosensitive element, method for forming resist pattern, and method for producing printed wiring board

The present invention relates to a photosensitive resin composition for permanent mask resist, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board.

Conventionally, permanent mask resists in the production of printed wiring boards have been produced by a screen printing method using heat or ultraviolet curable resist ink. In recent years, with the high integration of electronic devices, it has become necessary to increase the definition of wiring patterns and insulating patterns in printed wiring boards. However, in the conventional resist forming method by screen printing, bleeding and sagging occur at the time of printing, and it is difficult to form a high-definition resist image. Therefore, in order to form a high-definition resist image, a resist image forming method by photolithography has been developed.

Specifically, the resist image forming method by photolithography is a method in which a dry film type photosensitive resist is thermocompression-bonded on a substrate, or a liquid photosensitive resist is curtain-coated or spray-coated on a substrate, A resist image is formed by irradiating actinic rays such as ultraviolet rays through a negative mask and then developing.

By the way, as a method for forming a resist pattern, a so-called direct drawing exposure method in which a resist pattern is directly drawn without using a mask pattern has attracted attention. According to this direct drawing exposure method, it is considered that a resist pattern can be formed with high productivity and high resolution, and it is possible to improve positional accuracy that can cope with various distortions of the substrate. . Furthermore, in recent years, direct drawing exposure machines having a wide wavelength range of exposure wavelengths of 350 to 450 nm are becoming practically available.

Several photosensitive resin compositions intended for resist pattern formation by a direct drawing exposure method using laser light having an exposure wavelength of 405 nm as an active light source have been proposed so far (see, for example, Patent Documents 1 and 2). .

Several photosensitive resin compositions using nitroxyl compounds have been proposed (see, for example, Patent Documents 3 to 6).

JP 2002-296664 A JP 2004-45596 A JP 2003-140329 A JP 2003-215790 A JP 2006-11397 A JP 2007-133398 A

However, although the photosensitive resin compositions described in

Patent Documents

1 and 2 have good sensitivity to light having an exposure wavelength of about 405 nm, in a direct drawing exposure machine having a wide wavelength range from 350 to 450 nm, The tolerance for the exposure amount is narrow, and it is difficult to form a resist pattern with good reproducibility between samples and within the same substrate. Further, the photosensitive resin compositions described in Patent Documents 3 to 6 are not compatible with a direct drawing exposure machine having a wide wavelength range of an exposure wavelength of 350 to 450 nm, and are resistant to heat as a permanent mask resist. There is room for improvement in forming a high-performance cured film excellent in moisture and heat resistance, adhesion, mechanical properties, and electrical properties.

The present invention relates to a photosensitive resin composition for permanent mask resist, which has a wide tolerance for exposure amount and can form a resist pattern with good reproducibility between samples and within the same substrate, a photosensitive element using the same, and a method for forming a resist pattern And it aims at providing the manufacturing method of a printed wiring board.

The present invention includes (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerization initiator, and (C) a nitroxyl compound, and (C) the nitroxyl compound is represented by the following general formula (1). There is provided a photosensitive resin composition for a permanent mask resist containing the represented compound.

[In the formula (1), R ₁ is a hydroxy group, an alkyl group having 1 to 5 carbon atoms, an acetamide group, an amino group, a chloroacetamide group, a cyano group, a benzoyloxy group, or a group represented by the following general formula (2) Indicates. ]

[In the formula (2), n1 represents an integer of 1 to 12. ]

According to such a photosensitive resin composition, it is possible to widen the exposure tolerance, and it is possible to form a resist pattern with good reproducibility between samples and within the same substrate, particularly with good reproducibility of via shape. It is. In addition, it is possible to perform resist pattern formation using exposure light in the wavelength range of 350 nm to 450 nm and resist pattern formation by a direct drawing exposure method with sufficient sensitivity and resolution.

Furthermore, according to the photosensitive resin composition of the present invention having the above-described configuration, a high-performance cured film excellent in heat resistance, heat and humidity resistance, adhesion, mechanical properties, and electrical properties can be formed. It can be suitably used for the production of high-density multilayer boards and semiconductor packages.

The photosensitive resin composition of the present invention uses the exposure light in the wavelength range of 350 nm to 450 nm while maintaining excellent properties of developability, adhesion, heat resistance and solvent resistance as a solder resist due to the above configuration. Therefore, the resist pattern can be formed with better sensitivity and resolution, and in particular, the exposure tolerance can be improved.

The content of the (A) acid-modified vinyl group-containing epoxy resin is preferably 25% by mass or more based on the total solid content of the photosensitive resin composition.

The (A) acid-modified vinyl group-containing epoxy resin includes a novolac type epoxy resin represented by the following general formula (3), a bisphenol type epoxy resin represented by the following general formula (4), and the following general formula (5 A resin obtained by reacting at least one epoxy resin (a) selected from the group consisting of salicylaldehyde-type epoxy resins represented by (1) with a vinyl group-containing monocarboxylic acid (b). preferable.

[In the formula (3), R ₆ represents a hydrogen atom or a methyl group, Y ₁ represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70). , N ₂ represents an integer of 1 or more. A plurality of R ₆ and Y ₁ may be the same or different. ]

[In the formula (4), R ₇ represents a hydrogen atom or a methyl group, and Y ₂ represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70). , N ₃ represents an integer of 1 or more. A plurality of R ₇ and Y ₂ may be the same or different. ]

[In Formula (5), Y ₃ represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70), and n ₄ represents an integer of 1 or more. A plurality of Y ₃ may be the same or different. ]

The present invention also provides a photosensitive element comprising a photosensitive layer made of the above-described photosensitive resin composition for permanent mask resist on a support.

The present invention also includes a lamination step of laminating a photosensitive layer composed of the photosensitive resin composition for a permanent mask resist or a photosensitive layer of the photosensitive element on a substrate, and irradiating the photosensitive layer with an actinic ray in an image form. Provided is a resist pattern forming method including an exposure step of photocuring an exposed portion and a developing step of removing a region other than the exposed portion.

The present invention further provides a method for producing a printed wiring board, wherein a permanent mask is formed on a substrate by the method for forming a resist pattern of the present invention.

According to the method for forming a resist pattern and the method for producing a printed wiring board, since the photosensitive resin composition of the present invention is used, characteristics excellent in developability, adhesion, heat resistance, and solvent resistance are obtained. The resist pattern can be formed with sufficient sensitivity and resolution using exposure light within a wavelength range of 350 nm to 450 nm while maintaining the same. Further, it is possible to efficiently form a cured film such as a permanent mask (solder resist) that can form a resist pattern with good reproducibility such as a via shape between samples and within the same substrate with a wide tolerance to the exposure amount.

The present invention relates to a photosensitive resin composition for permanent mask resist, which has a wide tolerance for exposure amount and can form a resist pattern with good reproducibility between samples and within the same substrate, a photosensitive element using the same, and a method for forming a resist pattern And the manufacturing method of a printed wiring board can be provided.

(A) is a schematic cross-sectional view showing a core substrate with a build-up layer formed, (b) is a schematic cross-sectional view showing a photosensitive layer forming step, (c) is a schematic cross-sectional view showing an exposure step, and (d) is a resist. FIG. 5E is a schematic cross-sectional view showing a pattern forming process, and FIG. 5E is a schematic cross-sectional view showing a permanent mask resist forming process. (A) is a schematic cross section which shows an electroless gold Ni plating process, (b) is a schematic cross section which shows an electrolytic gold plating process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. In addition, (meth) acrylic acid in the present invention means acrylic acid or methacrylic acid, and the same applies to other similar expressions such as (meth) acrylate.

The photosensitive resin composition of the present invention comprises (A) an acid-modified vinyl group-containing epoxy resin (hereinafter sometimes referred to as “component (A)”) and (B) a photopolymerization initiator (hereinafter sometimes referred to as “( B) component ") and (C) a nitroxyl compound (hereinafter sometimes referred to as" (C) component "). Hereinafter, each component will be described in detail.

The component (A) is an epoxy resin containing an acid-modified vinyl group. For example, a resin obtained by modifying an epoxy resin with a vinyl group-containing monocarboxylic acid can be used. As the component (A), a novolac type epoxy resin represented by the following general formula (3), a bisphenol A type epoxy resin or a bisphenol F type epoxy resin represented by the following general formula (4), and the following general formula ( 5) Use of a resin obtained by reacting at least one epoxy resin (a) selected from the group consisting of salicylaldehyde type epoxy resins represented by 5) with a vinyl group-containing monocarboxylic acid (b). Is preferred.

In addition to the reaction product of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) (hereinafter referred to as “reaction product (A ′)”), the component (A) is a reaction product ( An addition reaction product obtained by adding a saturated or unsaturated group-containing polybasic acid anhydride (c) to A ′) is also used. Here, when the addition reaction product is synthesized, in the first reaction, a hydroxyl group is formed by the addition reaction of the epoxy group of the epoxy resin (a) and the carboxyl group of the vinyl group-containing monocarboxylic acid (b), and the next reaction And the resulting hydroxyl group (including the hydroxyl group originally contained in the epoxy resin (a)) and the acid anhydride group of the saturated or unsaturated group-containing polybasic acid anhydride (c) undergo a half-ester reaction. Inferred.

Examples of the novolak type epoxy resin represented by the general formula (3) include a phenol novolak type epoxy resin and a cresol novolak type epoxy resin. These novolak-type epoxy resins can be obtained by, for example, reacting a phenol novolak resin or a cresol novolak resin with epichlorohydrin by a known method.

In the compound represented by the general formula (4), the bisphenol A type epoxy resin or bisphenol F type epoxy resin in which Y ₂ is a glycidyl group is, for example, a bisphenol A type represented by the following general formula (6). It can be obtained by reacting a hydroxyl group of epoxy resin or bisphenol F type epoxy resin with epichlorohydrin.

[In Formula (6), R ₇ represents a hydrogen atom or a methyl group, and n ₃ represents an integer of 1 or more. A plurality of R ₇ may be the same or different. ]

In order to promote the reaction between the hydroxyl group and epichlorohydrin, the reaction is preferably carried out in a polar organic solvent such as dimethylformamide, dimethylacetamide or dimethylsulfoxide in the presence of an alkali metal hydroxide at a reaction temperature of 50 to 120 ° C. When the reaction temperature is 50 ° C. or higher, the reaction can be accelerated, and when the reaction temperature is 120 ° C. or lower, side reactions can be suppressed.

Specific examples of the salicylaldehyde type epoxy resin represented by the above general formula (5) include FAE-2500, EPPN-501H, EPPN-502H (the product name, manufactured by Nippon Kayaku Co., Ltd.) and the like.

Examples of the vinyl group-containing monocarboxylic acid (b) include acrylic acid, a dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α- And cyanocinnamic acid. In addition, a half-ester compound which is a reaction product of a hydroxyl group-containing acrylate and a saturated or unsaturated dibasic acid anhydride, and a vinyl group-containing monoglycidyl ether or vinyl group-containing monoglycidyl ester and a saturated or unsaturated dibasic acid anhydride The half-ester compound which is a reaction product with is mentioned. These vinyl group-containing monocarboxylic acids (b) can be used singly or in combination of two or more.

Examples of the hydroxyl group-containing acrylate used in the synthesis of the half ester compound as an example of the vinyl group-containing monocarboxylic acid (b) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. , Polyethylene glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate. Examples of the vinyl group-containing monoglycidyl ester include glycidyl acrylate and glycidyl methacrylate.

Examples of the saturated or unsaturated dibasic acid anhydride used in the synthesis of the half ester compound include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, and ethyltetrahydrophthalic anhydride. Acids, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride and itaconic anhydride.

In the reaction of the epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b), the vinyl group-containing monocarboxylic acid (b) is 0.6 to 1. The reaction is preferably carried out at a ratio of 05 equivalents, more preferably carried out at a ratio of 0.8 to 1.05 equivalents, particularly preferably carried out at a ratio of 0.9 to 1.0 equivalents.

The epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) are preferably dissolved and reacted in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Examples include hydrogen and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Furthermore, it is preferable to use a catalyst to promote the reaction. Examples of the catalyst used include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylmethylammonium iodide, and triphenylphosphine. The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b).

It is also preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol and pyrogallol. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). The reaction temperature is preferably 60 to 150 ° C., more preferably 80 to 120 ° C.

If necessary, a vinyl group-containing monocarboxylic acid (b) and a phenolic compound such as p-hydroxyphenethyl alcohol, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic acid A polybasic acid anhydride such as an anhydride can be used in combination.

In addition, (A) the acid-modified vinyl group-containing epoxy resin has a wide tolerance with respect to the exposure amount, and the above-mentioned reaction product is formed in that a resist pattern with good reproducibility such as a via shape is formed between samples and within the same substrate. It is preferable to use a resin obtained by reacting the product (A ′) with a saturated or unsaturated group-containing polybasic acid anhydride (c).

Examples of the saturated or unsaturated group-containing polybasic acid anhydride (c) include compounds exemplified as the saturated or unsaturated dibasic acid anhydride used in the synthesis of the half ester compound.

In the reaction of the reaction product (A ′) with the saturated or unsaturated group-containing polybasic acid anhydride (c), the saturated or unsaturated group-containing polyhydric acid is used with respect to 1 equivalent of the hydroxyl group in the reaction product (A ′). By reacting 0.1 to 1.0 equivalent of the basic acid anhydride (c), the acid value of the acid-modified vinyl group-containing epoxy resin (A) can be adjusted.

As the component (A), a polyurethane compound obtained by reacting an epoxy acrylate compound having two or more hydroxyl groups and a vinyl group, a diisocyanate compound, and a diol compound having a carboxyl group may be used. Such polyurethane compounds are commercially available, for example, as UXE-3011, UXE-3012, UXE-3024 (above, Nippon Kayaku Co., Ltd., trade name).

(A) The acid value of the acid-modified vinyl group-containing epoxy resin is preferably 30 to 150 mgKOH / g, more preferably 50 to 120 mgKOH / g, and still more preferably 60 to 100 mgKOH / g. When the acid value is 30 mgKOH / g or more, the solubility of the photosensitive resin composition in a dilute alkali solution tends to be improved, and when it is 150 mgKOH / g or less, the electric characteristics of the obtained cured film tend to be improved. . The acid value of the component (A) can be measured as follows. That is, first, 1 g of a resin whose acid value is to be measured is precisely weighed, and then 30 g of acetone is added to this resin to dissolve it uniformly. When the resin contains a volatile component such as a synthetic solvent or a dilution solvent, the resin is heated in advance at a temperature about 10 ° C. higher than the boiling point of the volatile component for 1 to 4 hours to remove the volatile component. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N potassium hydroxide (KOH) aqueous solution. The acid value is determined by calculating the number of mg of KOH required to neutralize the acetone solution of the resin to be measured. When a solution in which a resin is mixed with a synthetic solvent, a diluting solvent, or the like is a measurement target, the acid value is calculated by the following formula.
Acid value = 0.1 × Vf × 56.1 / (Wp × I / 100)
In the formula, Vf represents the titration amount (mL) of KOH, Wp represents the weight (g) of the solution containing the measured resin, and I represents the non-volatile content (mass%) in the solution containing the measured resin. ).

The reaction temperature between the reaction product (A ′) and the saturated or unsaturated group-containing polybasic acid anhydride (c) is preferably 60 to 120 ° C.

Further, as necessary, as the epoxy resin (a), for example, a hydrogenated bisphenol A type epoxy resin can be partially used together. Furthermore, in addition to (A) acid-modified vinyl group-containing epoxy resin, styrene-maleic anhydride copolymer modified with hydroxyethyl (meth) acrylate or styrene-maleic anhydride copolymer modified with hydroxyethyl (meth) acrylate Some styrene-maleic acid resins such as products can be used in combination.

In the photosensitive resin composition, the content of the component (A) is preferably 25 to 70% by mass, more preferably 30 to 70% by mass, based on the total solid content of the photosensitive resin composition. Preferably, the content is 35 to 65% by mass. When this content is within the above range, a coating film that is more excellent in heat resistance, electrical properties, and chemical resistance tends to be obtained.

Examples of the component (B) include benzoin compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bis (diethylamino) benzophenone, Michler's ketone, 4 -Benzophenone compounds such as benzoyl-4'-methyldiphenyl sulfide; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl Ketone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -Acetophenone compounds such as butanone-1, (2,2-diethoxyacetophenone, N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2- Anthraquinone compounds such as amylanthraquinone and 2-aminoanthraquinone; Thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; Acetophenone dimethyl ketal, benzyldimethyl ketal, etc. 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl)

imi

2,4,5-triarylimidazole dimer such as sol dimer; acridine derivative such as 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane; 2,4,6-trimethyl Phosphine oxide compounds such as benzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime) )], Ethanone, oxime compounds such as 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime); anthracene such as dibutoxyanthracene These may be used alone or in combination of two or more. it can. Among these, it is preferable to contain a thioxanthone compound or an anthracene compound.

In the photosensitive resin composition, the content of the component (B) is preferably 0.5 to 30 parts by mass, based on 100 parts by mass of the total amount of the component (A), preferably 0.5 to 20 parts by mass. More preferred is 0.5 to 15 parts by mass. If this content is 0.5 parts by mass or more, the photosensitivity tends to be improved, and if it is 30 parts by mass or less, the heat resistance of the cured film tends to be improved.

Moreover, the nitroxyl compound which is (C) component is a compound which has a nitroxyl group represented by the following structural formula.

(C) A component contains the compound represented by following General formula (1).

[In the formula (2), n1 represents an integer of 1 to 12. ]

In the compound of the formula (1), R ₁ is preferably a hydroxy group, an acetamido group or a benzoyloxy group.

Examples of the compound represented by the formula (1) include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 4-hydroxy-2,2,6,6-tetramethyl. Piperidine-1-oxylbenzoate free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl Free radical, 4- (2-chloroacetamido) -2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 4-cyano-2,2,6,6-tetramethylpiperidine-1-oxyl free Examples include radicals and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical.

Other examples of the component (C) include 2,2,6,6-tetramethylpiperidine-1-oxyl free radical. These compounds can be used in combination with the compound represented by the general formula (1), but are difficult to use alone because of their high volatility.

In the photosensitive resin composition, the content of the component (C) is preferably 0.005 to 10 parts by mass, and 0.01 to 8 parts by mass based on 100 parts by mass of the total amount of the component (A). More preferred is 0.01 to 5 parts by mass. When the content is 0.005 parts by mass or more, the effect can be obtained more reliably, and when the content is 10 parts by mass or less, the sensitivity tends to be improved.

The photosensitive resin composition preferably contains (D) an epoxy resin (hereinafter sometimes referred to as “component (D)”) from the viewpoint of further improving the solvent resistance. (D) Epoxy resins include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F type epoxy resins such as bisphenol F diglycidyl ether, bisphenol S type epoxy resins such as bisphenol S diglycidyl ether, and biphenol diglycidyl. Biphenol type epoxy resins such as ether, bixylenol type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A type epoxy resins such as hydrogenated bisphenol A glycidyl ether, and these dibasic acid-modified diglycidyl ether type epoxy resins, Biphenyl aralkyl type epoxy resin, tris (2,3-epoxypropyl) isocyanurate and the like can be mentioned. These are used alone or in combination of two or more. The component (D) is different from the component (A).

Commercially available compounds can be used as these compounds. For example, examples of bisphenol A diglycidyl ether include Epicoat 828, Epicoat 1001, Epicoat 1002 (all manufactured by Japan Epoxy Resin Co., Ltd.), and the like. Examples of bisphenol F diglycidyl ether include Epicoat 807 (manufactured by Japan Epoxy Resin Co., Ltd.) and YSLV-80 (manufactured by Nippon Steel Chemical Co., Ltd.). Examples of bisphenol S diglycidyl ether include EBPS-200 (manufactured by Nippon Kayaku Co., Ltd.). And Epicron EXA-1514 (manufactured by Dainippon Ink & Chemicals, Inc.).

In addition, examples of biphenol diglycidyl ether include YL6121 (manufactured by Japan Epoxy Resin Co., Ltd.), and examples of bixylenol diglycidyl ether include YX4000H (manufactured by Japan Epoxy Resin Co., Ltd.). Further, examples of the hydrogenated bisphenol A glycidyl ether include ST-2004 and ST-2007 (both manufactured by Tohto Kasei Co., Ltd.).

Examples of the phenol biphenyl aralkyl type epoxy resin include NC-3000H (manufactured by Nippon Kayaku Co., Ltd.). These may be used alone or in combination of two or more.

Among the above, in terms of crack resistance, it is preferable to contain a bisphenol F type epoxy resin, a phenol biphenyl aralkyl type epoxy resin, or a bisphenol novolac type epoxy resin. Examples of the bisphenol F type epoxy resin include YSLV-80 (manufactured by Nippon Steel Chemical Co., Ltd.). Examples of the phenol biphenyl aralkyl type epoxy resin include NC-3000H (manufactured by Nippon Kayaku Co., Ltd.). Further, the bisphenol novolac type epoxy resin is available as EXA-7372 (bisphenol F type novolac type epoxy resin, manufactured by DIC), 157S70 (bisphenol A type novolak type polyfunctional epoxy resin, manufactured by Mitsubishi Chemical Corporation). These may be used alone or in combination of two or more.

When the component (D) is used, the content thereof is preferably 1 part by mass to 50 parts by mass, and more preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the component (A). The amount is more preferably 10 to 50 parts by weight, and particularly preferably 20 to 40 parts by weight.

It is preferable that the photosensitive resin composition further contains a diluent. As the diluent, for example, an organic solvent and / or a photopolymerizable monomer can be used. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate; aliphatic carbonization such as octane and decane Examples include hydrogen and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Examples of the photopolymerizable monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and the like. Mono- or di (meth) acrylates of glycol; (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide; amino such as N, N-dimethylaminoethyl (meth) acrylate Alkyl (meth) acrylates; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate Are polyvalent (meth) acrylates of these ethylene oxide or propylene oxide adducts and (meth) acrylic acid; ethylene oxide or propylene of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A (Meth) acrylates of oxide adducts; (meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, and melamine (meth) acrylate.

These diluents are used singly or in combination of two or more. Moreover, content of the organic solvent can be suitably adjusted for the purpose of adjusting the viscosity of the photosensitive resin composition.

When a diluent is used, the content thereof is preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the total amount of component (A). . If the content is 0.5 parts by mass or more, the photosensitivity is improved and the exposed part tends to be prevented from being eluted during development, and if it is 40 parts by mass or less, the heat resistance of the cured film is improved. Tend.

Also, from the viewpoint of further improving the heat resistance, the photosensitive resin composition according to the present embodiment can contain a curing agent.

As the curing agent, it reacts with heat, ultraviolet rays, etc., with a compound that cures itself by heat, ultraviolet rays, or the carboxyl group or hydroxyl group in component (A) which is a photocurable resin component in the photosensitive resin composition. A compound that cures by heating is preferred. By using a curing agent, the heat resistance, adhesion, chemical resistance, and the like of the finally obtained cured film can be improved.

Examples of the curing agent include an epoxy compound, a melamine compound, a urea compound, an oxazoline compound, and a block isocyanate compound as a thermosetting compound. Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolac type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin. And heterocyclic epoxy resins such as triglycidyl isocyanurate and bixylenol type epoxy resins. Examples of the melamine compound include triaminotriazine, hexamethoxymelamine, and hexabutoxylated melamine. Examples of the urea compound include dimethylol urea. These hardening | curing agents are used individually by 1 type or in combination of 2 or more types.

In the photosensitive resin composition, when a curing agent is used, the content thereof is preferably 1 to 60 parts by mass based on 100 parts by mass of the total amount of component (A), and preferably 5 to 50 parts by mass. More preferred. When this content is 1 part by mass or more, the heat resistance of the final cured coating film tends to be improved, and when it is 60 parts by mass or less, the developability tends to improve.

The photosensitive resin composition according to this embodiment preferably contains an epoxy resin curing agent for the purpose of further improving various properties such as heat resistance, adhesion, and chemical resistance of the cured film.

Specific examples of such epoxy resin curing agents include, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methyl Imidazole derivatives such as -5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazide, etc. Of these organic acid salts and / or epoxy adducts; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl- Triazine derivatives such as triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) melamine, 2,4,6-tris Tertiary amines such as (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine, tris-2- Organic phosphines such as cyanoethylphosphine; phosphonium such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosnium chloride Quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the above polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyri A lithium hexafluorophosphate is mentioned.

These epoxy resin curing agents are used singly or in combination of two or more. When an epoxy resin curing agent is used, the content thereof is preferably 1 to 60 parts by mass, and more preferably 5 to 50 parts by mass based on 100 parts by mass of the total amount of component (A).

The photosensitive resin composition according to the present embodiment further includes barium sulfate, barium titanate, silica, talc, and calcined kaolin for the purpose of further improving various properties such as adhesion and coating film hardness. In addition, known inorganic fillers such as magnesium carbonate, aluminum oxide, aluminum hydroxide, and mica can be contained. These can be used alone or in combination of two or more. Among these, silica or barium sulfate is preferable from the viewpoint of improving the printability and the hardness of the cured film. When the inorganic filler is used, its content is preferably 1 to 200 parts by weight, more preferably 5 to 150 parts by weight, based on 100 parts by weight of the total amount of component (A). More preferably, it is ˜120 parts by mass.

In the photosensitive resin composition, if necessary, known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black; hydroquinone, methylhydroquinone Polymerization inhibitors such as hydroquinone monomethyl ether, catechol and pyrogallol; thickeners such as benton and montmorillonite; silicone, fluorine and vinyl resin antifoaming agents; and various conventional and conventional additives such as silane coupling agents Can be used. In addition, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds phosphate compounds, aromatic condensed phosphate esters, halogen-containing condensed phosphate esters, adhesion imparting agents, leveling agents, Antioxidants, pigments and the like can be used.

The photosensitive resin composition can be obtained by uniformly kneading or mixing each of the above-described blending components with a roll mill, a bead mill or the like.

Photosensitive resin compositions are used in the field of electronic materials such as solder resists in printed wiring boards, interlayer insulation films in high-density multilayer boards, solder resists for semiconductor packages, and image resistance, heat resistance, adhesion, mechanical properties, and chemical resistance. It is useful as a permanent mask resist having excellent properties and electrical characteristics.

Next, a photosensitive element using the above-described photosensitive resin composition will be described. The photosensitive element according to this embodiment includes a support and a photosensitive layer provided on the support. The photosensitive layer is a layer made of the above-described photosensitive resin composition. The photosensitive element may be coated with a protective film on the surface on the photosensitive layer opposite to the support.

The photosensitive layer is formed by dissolving the photosensitive resin composition according to this embodiment in the above solvent or mixed solvent to obtain a solution having a solid content of about 30 to 70% by mass, and then applying this solution on a support. It is preferable.

The thickness of the photosensitive layer varies depending on the application, but is preferably 10 to 100 μm, more preferably 20 to 60 μm, after drying after removing the solvent by heating and / or hot air blowing.

Examples of the support provided in the photosensitive element include polymer films having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester.

The thickness of the support is preferably 5 to 100 μm, more preferably 10 to 30 μm.

The photosensitive element consisting of two layers of the support and the photosensitive layer as described above or the photosensitive element consisting of three layers of the support, the photosensitive layer and the protective film may be stored as it is, for example. After interposing, it may be wound around the core in a roll shape and stored.

The method for forming a resist pattern according to an embodiment of the present invention includes a laminating step of laminating a photosensitive layer made of the above-described photosensitive resin composition on a substrate, and an exposed portion by irradiating the photosensitive layer with an actinic ray in an image form. Is an exposure process for photo-curing, and a development process for removing regions other than the exposed area.

Lamination of the photosensitive layer on the substrate (copper-clad laminate, etc.) is performed by coating the photosensitive resin composition with a method such as screen printing, spraying, roll coating, curtain coating, electrostatic coating, etc. The film can be applied on the substrate with a film thickness of 5 mm and dried at 60 to 110 ° C.

Moreover, you may laminate | stack a photosensitive layer on a board | substrate using the photosensitive element mentioned above. In this case, when the photosensitive element includes a protective film, the protective film is removed, and then the photosensitive layer is heated to about 70 ° C. to 130 ° C. while being applied to the substrate at about 0.1 MPa to 1 MPa (1 kgf). / Cm ² to 10 kgf / cm ² ). Such a lamination process may be performed under reduced pressure. The surface of the substrate on which the photosensitive layer is laminated is usually a metal surface, but is not particularly limited.

The photosensitive layer laminated on the substrate in this way is irradiated with actinic rays in the form of an image to photocur the exposed portion. Examples of the method of irradiating actinic rays in the form of an image include a method using a negative mask pattern and a direct drawing exposure method. In this case, when a photosensitive layer is laminated using a photosensitive element, a support is present on the photosensitive layer. When this support is transparent to actinic rays, the support is present. An actinic ray can be irradiated through. In the case where the support is light-shielding against actinic rays, the photosensitive layer is irradiated with actinic rays after the support is removed.

A conventionally known light source can be used as the active light source. For example, a lamp that effectively emits actinic rays, such as an ultraviolet ray such as a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or a xenon lamp, a gas laser such as an argon laser, or a solid laser such as a YAG laser is used.

After formation of the exposed portion, a region other than the exposed portion (unexposed portion of the photosensitive layer) is removed by development to form a resist pattern. As a method for removing such an unexposed portion, for example, when a support is present on the photosensitive layer, the support is removed with an auto peeler or the like, and wet development with a developer such as an alkaline aqueous solution, an aqueous developer, or an organic solvent is performed. Or a method of developing by removing an unexposed portion by dry development or the like. Examples of the alkaline aqueous solution used for wet development include a dilute solution of 0.1% by mass to 5% by mass of sodium carbonate, a dilute solution of 0.1-5% by mass of potassium carbonate, and 0.1% by mass to 5% by mass of hydroxide. A dilute solution of sodium and the like can be mentioned. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive layer. Moreover, you may mix surfactant, an antifoamer, an organic solvent, etc. in alkaline aqueous solution. Examples of the development method include a dip method, a spray method, brushing, and slapping.

Next, as a treatment after development, the exposed portion is sufficiently cured by post-exposure (ultraviolet light exposure) and / or post-heating to obtain a cured film. The post-exposure is preferably performed with an exposure amount of 1 to 5 J / cm ² . Post-heating is preferably performed at 100 to 200 ° C. for 30 minutes to 12 hours.

In the method for manufacturing a printed wiring board according to the embodiment of the present invention, the circuit forming substrate on which the resist pattern is formed by the above resist pattern forming method is etched or plated. Here, the resist pattern made of the photosensitive resin composition functions effectively as a permanent mask resist having excellent image forming properties, heat resistance, adhesion, mechanical properties, chemical resistance, electrical properties, and the like.

[Build-up board]
The photosensitive resin composition which concerns on this embodiment can be used suitably for formation of the permanent mask resist of the printed wiring board for buildup boards. That is, according to the present embodiment, it is possible to provide a build-up substrate having a permanent mask resist made of a cured product of the above-described photosensitive resin composition. 1 and 2 show an example in which a permanent mask resist is formed on a printed wiring board for a buildup board.

FIG. 1 (a) is a schematic cross-sectional view showing a core base material on which a buildup layer has been formed. A copper wiring 2 is formed on the core substrate 1. On this core substrate, the photosensitive layer 3 made of the photosensitive resin composition according to the present embodiment is formed on a substrate by lamination or coating (see FIG. 1B). Subsequently, the photosensitive layer 3 is exposed through an exposure mask 4 having a desired pattern (see FIG. 1C). Subsequently, development is performed to form a resist pattern having a desired opening (see FIG. 1D). A permanent mask resist 5 is formed on the substrate by exposing and heating the formed resist pattern (see FIG. 1E). Thereafter, electroless Ni gold plating is performed to provide an electroless Ni gold plating layer 6 (see FIG. 2A), and further, a step of performing electrolytic gold plating is performed to form an electrolytic gold plating layer 7 ( As shown in FIG. 2B, a build-up substrate is formed.

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

[Synthesis of Resin A]
In a flask equipped with a stirrer, a reflux condenser and a thermometer, 1052 parts by mass of (b) component as component (a), bisphenol F type epoxy resin (trade name: 806, manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent: 180) As above, 144 parts by mass of acrylic acid, 1 part by mass of methyl hydroquinone, 850 parts by mass of carbitol acetate and 100 parts by mass of solvent naphtha were charged and heated and stirred at 70 ° C. to dissolve the mixture. Next, the obtained solution is cooled to 50 ° C., 2 parts by mass of triphenylphosphine and 75 parts by mass of solvent naphtha are added thereto, heated to 100 ° C., and reacted until the solid content acid value becomes 1 mgKOH / g or less. I let you. Next, the obtained solution was cooled to 50 ° C., and 745 parts by mass of tetrahydrophthalic anhydride, 75 parts by mass of carbitol acetate and 75 parts by mass of solvent naphtha were added as component (c), and reacted at 80 ° C. for 3 hours. I let you. As a result, an unsaturated group-containing polycarboxylic acid resin (resin A) having a solid content acid value of 80 mgKOH / g and a solid content of 62% by mass was obtained as the component (A).

(Examples 1 to 12 and Comparative Examples 1 to 5)
After blending the composition according to the blending composition (unit: part by mass) shown in Table 1 below, carbitol acetate was added so that the solid content concentration would be 70% by weight to obtain a photosensitive resin composition. In addition, the compounding quantity of each component in following Table 1 shows the compounding quantity of solid content.

The details of each component in Table 1 are as follows.

(A) Component EXP-2810: Cresol novolac type acid-modified epoxy acrylate (weight average molecular weight 7000, acid value 65 mg KOH / g, manufactured by DIC),
ZAR-1753: Bisphenol A acid-modified epoxy acrylate (weight average molecular weight 10,000, acid value 70 mg KOH / g, manufactured by Nippon Kayaku Co., Ltd.)
UXE-3024: urethane-modified bisphenol A acid-modified epoxy acrylate (weight average molecular weight 10,000, acid value 67 mgKOH / g, manufactured by Nippon Kayaku Co., Ltd.)

(B) Component I-907: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (Irgacure 907, manufactured by Ciba Specialty Chemicals),
I-651: 2,2-dimethoxy-1,2-diphenylethane-1-one (2,2-dimethoxy-2-phenylacetophenone, IRGACURE 651, manufactured by BASF)
OXE-02: Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (IRGACURE-OXE-02, manufactured by BASF ),
N-1919: Oxime ester photopolymerization initiator (Adekaoptomer N-1919, manufactured by ADEKA),
TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (LUCIRIN-TPO, manufactured by BASF),
I-819: Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE-819, manufactured by BASF),
DETX: 2,4-diethylthioxanthone (KAYACURE-DETX-S, manufactured by Nippon Kayaku Co., Ltd.)
DBA: 9,10-dibutoxyanthracene (trade name, manufactured by Kawasaki Kasei Kogyo Co., Ltd.).

(C) Component 4-hydroxy-TEMPO: 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.)
4-benzoyloxy-TEMPO: 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxylbenzoate free radical (manufactured by Tokyo Chemical Industry Co., Ltd.)
4-acetamido-TEMPO: 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.).

(D) Component NC-3000H: biphenyl aralkyl type epoxy resin (product name) manufactured by Nippon Kayaku Co., Ltd.
YSLV-80: Bisphenol F type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd., trade name).

Other components DPHA: dipentaerythritol hexaacrylate (Kayarad DPHA, manufactured by Nippon Kayaku Co., Ltd.)
C11-A: imidazole compound (manufactured by Shikoku Kasei Kogyo Co., Ltd.)
ESLV-120TE: 1,3,5-triglycidyl isocyanate (manufactured by Nippon Steel Chemical Co., Ltd.)
TBC: 4-t-butylcatechol (manufactured by DIC),
Phthalocyanine green: (Sanyo dye company)
γ-glycidoxypropyltriethoxysilane: (manufactured by Shin-Etsu Silicone),
Barium sulfate: B-30 (manufactured by Sakai Chemical)
Silica: SC-2050 (manufactured by Admatechs),
Melamine: (Nissan Chemical)
PB3600: Epoxidized polybutadiene (manufactured by Daicel),
Pigment: phthalocyanine blue (manufactured by Toyo Ink).

(Production of Evaluation Board A)
The photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were applied on a copper clad laminate so that the thickness after drying was 20 μm by a spin coater, and 10 minutes at 75 ° C. by a hot plate. Dried. A 16 μm thick polyethylene terephthalate film was laminated at 80 ° C. on the coated surface to obtain an evaluation substrate. Each characteristic was evaluated by the method shown below using the obtained test plate. The results are summarized in Table 2.
(Production of evaluation board B)
A photosensitive layer is obtained by uniformly coating the photosensitive resin compositions of Examples 4 to 12 and Comparative Examples 3 to 5 on a 16 μm-thick polyethylene terephthalate film (G2-16, trade name, manufactured by Teijin Limited) as a support. Was dried at 100 ° C. for about 10 minutes using a hot air convection dryer. The film thickness after drying of the photosensitive layer was 25 μm.

Subsequently, on the surface of the photosensitive layer opposite to the side in contact with the support, a polyethylene film (NF-15, product name, manufactured by Tamapoly Co., Ltd.) was bonded as a protective film to obtain a photosensitive element. Next, the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil was laminated on a glass epoxy substrate was polished with an abrasive brush, washed with water and dried. Using a press-type vacuum laminator (MVLP-500, trade name, manufactured by Meiki Seisakusho) on this printed wiring board substrate, the press hot plate temperature is 70 ° C., the evacuation time is 20 seconds, the lamination press time is 30 seconds, and the atmospheric pressure is 4 kPa. Hereinafter, the protective film of the photosensitive element was peeled and laminated under the condition of a pressure bonding pressure of 0.4 MPa to obtain an evaluation substrate. Each characteristic was evaluated by the method shown below using the obtained test plate. The results are summarized in Table 2.

(Developability)
A mask with a via mask opening dimension of 100 μm is placed on the photosensitive layer of the evaluation substrate, and irradiated with an integrated exposure dose of 200 mJ / cm ² using a parallel light exposure machine (trade name: EXM-1201, manufactured by Oak Manufacturing Co., Ltd.), 1% Spray development was performed with a sodium carbonate aqueous solution at a pressure of 0.176 MPa (1.8 kgf / cm ² ) for 60 seconds. Thereafter, the evaluation substrate was visually observed to confirm the presence or absence of the development residue, and evaluated according to the following criteria.
A: No development residue.
B: Development remains.

(Resolution)
Using a photo tool having a wiring pattern of line width / space width = 6/6 to 47/47 (unit: μm) as a negative for resolution evaluation on the photosensitive layer of the evaluation substrate, a parallel light exposure machine (trade name: Evaluation was performed by exposing an integrated exposure amount of 200 mJ / cm ² using EXM-1201 (manufactured by Oak Manufacturing Co., Ltd.). Here, the unexposed portion can be removed cleanly by the development processing after exposure, and the smallest value (unit: μm) of the line width / space width formed without causing meandering or chipping of the line, Resolution was assumed. The smaller the numerical value, the better the evaluation of resolution.

(Exposure tolerance)
A pattern of via width / space width = 50/50 (unit: μm) was applied to the photosensitive layer of the evaluation substrate using a parallel light exposure machine (trade name: EXM-1201, manufactured by Oak Manufacturing Co., Ltd.). / Cm ² to 600 mJ / cm ² . Thereafter, spray development was performed with a 1% aqueous sodium carbonate solution for 60 seconds at a pressure of 0.176 MPa (1.8 kgf / cm ² ). The amount of exposure until the 50 μm via was completely filled was observed and evaluated according to the following criteria.
A: 50 μm vias are not filled between 200 and 600 mJ / cm ² .
B: A 50 μm via is not buried between 200 and 400 mJ / cm ² , but is buried when it exceeds 400 mJ / cm ² .
C: Filled when a 50 μm via exceeds 300 mJ / cm ² .

(Via shape reproducibility (1) Center vs. end of same pattern)
A pattern of via width / space width = 100/100 (unit: μm) was applied to the photosensitive layer of the evaluation substrate using a direct drawing exposure machine LI-9700 (Dainippon Screen Co., Ltd.) with an integrated exposure amount of 200 mJ / cm ^2. Irradiated with. Thereafter, spray development was performed with a 1% aqueous sodium carbonate solution for 60 seconds at a pressure of 0.176 MPa (1.8 kgf / cm ² ). The via shapes at the center and the end in the same substrate were compared.
A: A good via shape is formed at both the center and the end.
B: The shape of the via at the center or end is not good.

(Via shape reproducibility (2) Space width 100 vs. 10 (unit: μm))
Using a direct drawing exposure machine LI-9700 (manufactured by Dainippon Screen Co., Ltd.), a pattern with a via width of 100 μm and a space width of 100 μm or 10 μm is irradiated to the photosensitive layer of the evaluation substrate with an integrated exposure amount of 200 mJ / cm ² . did. Thereafter, spray development was performed with a 1% aqueous sodium carbonate solution for 60 seconds at a pressure of 0.176 MPa (1.8 kgf / cm ² ). The via shapes with a space width of 100 μm and 10 μm and a via width of 100 μm were compared.
A: A good via shape is formed in both space widths of 100 μm and 10 μm.
B: The via shape having a space width of 100 μm or 10 μm is not good.

(Solvent resistance)
After immersing the test plate in isopropyl alcohol at room temperature for 30 minutes, it was visually confirmed whether or not the appearance of the cured film was abnormal. Then, the peeling test which sticks a cellophane tape on a cured film and pulls up was performed, and it was confirmed whether the cured film peeled from a copper clad laminated board. From these results, solvent resistance was evaluated according to the following criteria.
A: There is no abnormality in the appearance of the cured film, and there is no peeling in the peeling test.
B: The appearance of the cured film is abnormal or peeled off in the peel test.

(Solder heat resistance)
After applying the rosin flux to the surface of the cured film of the test plate, it was immersed in a solder bath at 260 ° C. for 10 seconds. After repeating this for 6 cycles, the appearance of the cured film was visually observed, and the solder heat resistance was evaluated according to the following criteria.
A: There is no abnormality (peeling or swelling) in the appearance of the cured film, and there is no solder peeling.
B: The appearance of the cured film is abnormal (peeling or swelling), or there is solder peeling.

(Adhesion)
A peel test was performed on the test plate by a method according to JIS K5400. That is, 100 1 mm grids were prepared on the cured film of the test plate, and the cellophane tape was attached to the grids, and then peeled off. The peeled state after the peeling was observed, and the adhesion was evaluated according to the following criteria.
A: 90/100 or more of the grids were not peeled.
B: 50/100 or more and less than 90/100 of the grids were not peeled.
C: Less than 50/100 grids were not peeled.

DESCRIPTION OF SYMBOLS 1 ... Core base material with build-up layer formed, 2 ... Copper wiring, 3 ... Photosensitive layer, 4 ... Exposure mask, 5 ... Permanent mask resist, 6 ... Electroless Ni gold plating layer, 7 ... Electrolytic gold plating layer.

Claims

(A) an acid-modified vinyl group-containing epoxy resin;
(B) a photopolymerization initiator;
A photosensitive resin composition for permanent mask resist, comprising (C) a nitroxyl compound, wherein the (C) nitroxyl compound comprises a compound represented by the following general formula (1).

[In the formula (1), R 1 is a hydroxy group, an alkyl group having 1 to 5 carbon atoms, an acetamide group, an amino group, a chloroacetamide group, a cyano group, a benzoyloxy group, or a group represented by the following general formula (2) Indicates. ]

[In the formula (2), n1 represents an integer of 1 to 12. ]
2. The photosensitive resin composition for permanent mask resist according to claim 1, wherein the content of the (A) acid-modified vinyl group-containing epoxy resin is 25% by mass or more based on the total solid content of the photosensitive resin composition. object.
(A) Acid-modified vinyl group-containing epoxy resin
The group consisting of a novolac type epoxy resin represented by the following general formula (3), a bisphenol type epoxy resin represented by the following general formula (4), and a salicylaldehyde type epoxy resin represented by the following general formula (5) At least one epoxy resin (a) selected from:
A vinyl group-containing monocarboxylic acid (b);
The photosensitive resin composition for permanent mask resists of Claim 1 or 2 which is resin obtained by making this react.

[In the formula (3), R 6 represents a hydrogen atom or a methyl group, Y 1 represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70). , N 2 represents an integer of 1 or more. A plurality of R 6 and Y 1 may be the same or different. ]

[In the formula (4), R 7 represents a hydrogen atom or a methyl group, and Y 2 represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70). , N 3 represents an integer of 1 or more. A plurality of R 7 and Y 2 may be the same or different. ]

[In Formula (5), Y 3 represents a hydrogen atom or a glycidyl group (wherein hydrogen atom / glycidyl group (molar ratio) is 0/100 to 30/70), and n 4 represents an integer of 1 or more. A plurality of Y 3 may be the same or different. ]
A photosensitive element comprising a photosensitive layer comprising the photosensitive resin composition for permanent mask resist according to any one of claims 1 to 3 on a support.
A laminating step of laminating a photosensitive layer comprising the photosensitive resin composition for a permanent mask resist according to any one of claims 1 to 3 or a photosensitive layer of the photosensitive element according to claim 4; A method for forming a resist pattern, comprising: an exposure step of irradiating a photosensitive layer with an actinic ray in an image to photocure an exposed portion; and a developing step of removing a region other than the exposed portion.
A method for manufacturing a printed wiring board, wherein a permanent mask is formed on a substrate by the method for forming a resist pattern according to claim 5.