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

Abstract

A photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photoinitiator (C), wherein the photoinitiator (C) contains a hexaarylbiimidazole compound (C1) that has an alkoxy group having three or more carbon atoms in a molecular structure.

Description

Photosensitive resin composition, photosensitive element, method for forming resist patterns, and method for manufacturing printed wiring boards

[0001] This disclosure relates to a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed circuit board.

[0002] In the field of printed circuit board manufacturing, photosensitive resin materials are widely used as resist materials in processes such as etching and plating. Laminated film type photosensitive elements, in which a photosensitive resin material layer is formed on a support film and a protective film is placed on top of it, are available on the market.

[0003] Recently, circuit patterns have become increasingly miniaturized, and there is a need for the development of photosensitive resin materials that can accommodate this. Basic and important performance requirements for photosensitive resin materials include the ability to be sufficiently photosensitive even with low exposure and to form high-resolution patterns. Furthermore, there is a growing demand for reduced environmental impact and improved safety in the industrial environment for industrial chemical products, and the development of halogen-free products is one way to address this.

[0004] Photosensitive resin materials mainly consist of radical polymerizable compounds and photopolymerization initiators, and hexaarylbiimidazole compounds having a chloro group (hereinafter sometimes referred to as "HABI") are widely used as polymerization initiators. However, there are concerns about the environmental impact of these compounds because they contain halogen atoms, and the application of HABI in which the chloro group is replaced with an alkoxy group is being investigated (see Patent Documents 1 and 2).

[0005] Japanese Patent Publication No. 2011-237736

[0006] As mentioned above, the development of photosensitive resin compositions that do not contain halogen-free atoms has been considered, but known HABIs such as those described in Patent Document 1 have not met the performance levels required in terms of light sensitivity and resolution.

[0007] One of the objectives of this disclosure is to provide a photosensitive resin composition with excellent photosensitivity, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed circuit board.

[0008] This disclosure includes, but is not limited to, the following embodiments. One embodiment relates to a photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaarylbiimidazole compound (C1) having an alkoxy group with three or more carbon atoms in its molecular structure.

[0009] This disclosure provides a photosensitive resin composition with excellent light sensitivity, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed circuit board.

[0010] The embodiments of this disclosure are described in detail below. This disclosure is not limited to the embodiments described below.

[0011] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limits of numerical ranges described in this disclosure may be replaced with the values ​​shown in the examples.

[0012] Unless otherwise specified, the photosensitive resin compositions of this disclosure may contain one or more substances corresponding to each component.

[0013] In this disclosure, if a photosensitive resin composition contains multiple substances that fall under a certain component, the content of such component in the photosensitive resin composition means the total amount of such multiple substances present in the photosensitive resin composition, unless otherwise specified.

[0014] In this disclosure, (meth)acrylic acid means at least one of acrylic acid and methacrylic acid. (Meth)acrylate means at least one of acrylate and the corresponding methacrylate. (Meth)acryloyl group means at least one of acryloyl group and methacryloyl group.

[0015] In this disclosure, unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The GPC conditions are as follows.

[0016] Detector: L-2490 RI (manufactured by Hitachi, Ltd.) Column: Gelpack GL-R440, Gelpack GL-R450, and Gelpack GL-R400M (manufactured by Resonaq Techno Service Co., Ltd.) Eluent: Tetrahydrofuran Sample concentration: 5 mg / 1 mL Injection volume: 200 μL Flow rate: 2.05 mL / min Measurement temperature: 40°C

[0017] One embodiment of the present disclosure is a photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaarylbiimidazole compound (C1) having an alkoxy group with 3 or more carbon atoms in its molecular structure.

[0018] Hexaarylbiimidazole compounds (C1) having an alkoxy group with three or more carbon atoms in their molecular structure (hereinafter sometimes referred to as "HABI(C1)") have superior photosensitivity compared to HABI having a halogen atom in its molecular structure. Specifically, when the photosensitive resin composition of one embodiment is used as a material for forming resist patterns, the required exposure can be reduced without increasing the amount of photopolymerization initiator (C) added. While this reason is not bound by any particular theory, it is possible that the absorbance of light at the wavelength used for resist pattern formation is higher for HABI(C1) compared to HABI having a halogen atom.

[0019] In addition, as compared with HABI (C1) having an alkoxy group with less than 3 carbon atoms, the solubility of HABI in components other than the photoinitiator (C) in the photosensitive resin composition is improved due to the increase in the number of carbon atoms in the alkoxy group, and it has become applicable to even finer regions. Specifically, it is also applicable to applications where the resolution is in the range of 4 to 5 μm.

[0020] [Binder Polymer (A)] By containing a binder polymer, the photosensitive resin composition of the present embodiment can further enhance the resolution and adhesion.

[0021] The component (A) may include a binder polymer having at least one of a divalent group represented by the following general formula (2), a divalent group represented by the following general formula (3), a divalent group represented by the following general formula (4), and a divalent group represented by the following general formula (5). Thereby, the resolution and adhesion of the photosensitive resin composition are further improved. Furthermore, the development time and peeling time can be further shortened.

[0022]

[0023] In formula (2), R １ represents a hydrogen atom or a methyl group, R ２ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group or a halogen atom, and a plurality of R ２ may be the same as or different from each other.

[0024]

[0025] In formula (3), R ３ represents a hydrogen atom or a methyl group.

[0026]

[0027] In formula (4), R ４ represents a hydrogen atom or a methyl group, R ５ represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group or a halogen atom, a represents an integer of 0 to 5, and a plurality of R ５ may be the same as or different from each other.

[0028]

[0029] In formula (5), R6 represents a hydrogen atom or a methyl group, and R ７ represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom, b represents an integer of 0 to 5, and a plurality of R ７ may be the same as or different from each other.

[0030] The weight average molecular weight (Mw) of component (A) may be 8,000 to 100,000, 10,000 to 80,000, 15,000 to 70,000, or 20,000 to 50,000. When Mw is 100,000 or less, the resolution and developability tend to improve. When Mw is 8,000 or more, the flexibility of the cured film improves, and the occurrence of chipping and peeling of the resist pattern tends to be difficult. The dispersity (Mw / Mn) of component (A) may be 1.0 to 3.0, 1.2 to 2.5, 1.4 to 2.3, or 1.5 to 2.0. When the dispersity decreases, the resolution tends to improve. The weight average molecular weight of the binder polymer (A) is measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene).

[0031] In the photosensitive resin composition of the present embodiment, component (A) may be used alone as one kind of binder polymer, or two or more kinds of binder polymers may be arbitrarily combined and used. Examples of the binder polymer when two or more kinds are used in combination include two or more kinds of binder polymers composed of different copolymerization components (including different monomer units as copolymerization components), and two or more kinds of binder polymers having different Mw.

[0032] The acid value of component (A) may be 100 to 250 mgKOH / g, 120 to 240 mgKOH / g, 140 to 230 mgKOH / g, or 150 to 230 mgKOH / g. When the acid value of component (A) is 100 mgKOH / g or more, the development time can be sufficiently suppressed from becoming long, and when it is 250 mgKOH / g or less, the developability resistance (adhesion) of the cured product of the photosensitive resin composition tends to improve.

[0033] (A) The acid value of component (A) can be measured as follows. First, 1 g of the binder polymer to be measured is accurately weighed. 30 g of acetone is added to the accurately weighed binder polymer and dissolved uniformly. Next, an appropriate amount of phenolphthalein, an indicator, is added to the solution and titrated with a 0.1 N 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 binder polymer to be measured. When the binder polymer is mixed with a synthesis solvent, dilution solvent, etc., the acid value is calculated using the following formula: Acid value = 0.1 × Vf × 56.1 / (Wp × I / 100) In the formula, Vf represents the titration volume (mL) of the KOH aqueous solution, Wp represents the mass (g) of the solution containing the measured binder polymer, and I represents the percentage (mass%) of non-volatile matter in the solution containing the measured binder polymer. Furthermore, when the binder polymer is formulated in a state mixed with volatile components such as the synthesis solvent or diluent, it is also possible to pre-measure the acid value after heating the mixture at a temperature at least 10°C higher than the boiling point of the volatile components for 1 to 4 hours to remove the volatile components before accurate weighing.

[0034] The content of component (A) in the photosensitive resin composition of this embodiment may be 20 to 90% by mass, 30 to 80% by mass, or 40 to 65% by mass, based on the total solid content of the photosensitive resin composition. When the content of component (A) is 20% by mass or more, the film tends to be more moldable, and when it is 90% by mass or less, the film tends to be more sensitive and resolving.

[0035] [Photopolymerizable compound (B)] The photopolymerizable compound (B) is not particularly limited as long as it has at least one ethylenically unsaturated bond and is photopolymerizable. From the viewpoint of improving alkali developability, resolution, and peelability after curing, component (B) preferably contains at least one bisphenol-type (meth)acrylate, and more preferably contains bisphenol A-type (meth)acrylate among bisphenol-type (meth)acrylates. Examples of bisphenol A-type (meth)acrylates include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane. In particular, 2,2-bis(4-(meth)acryloxypolyethoxy)phenyl)propane is preferred from the viewpoint of further improving resolution and peeling properties.

[0036] Examples of commercially available bisphenol A type (meth)acrylates include BPE-200 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name) as 2,2-bis(4-((meth)acryloxydipropoxy)phenyl)propane, BP-2EM (manufactured by Kyoeisha Chemical Co., Ltd., trade name) as ethoxylated bisphenol A dimethacrylate, BPE-500 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name) as 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane, and FA-321M (manufactured by Resonaq Corporation, trade name). These bisphenol A type (meth)acrylates may be used individually or in combination of two or more types.

[0037] The content of bisphenol-type (meth)acrylate may be 40-98% by mass, 50-97% by mass, 60-95% by mass, or 70-95% by mass, based on the total amount of component (B). When the content is 40% by mass or more, resolution, adhesion, and suppression of resist edge formation are improved, and when it is 98% by mass or less, the development time is moderately shortened and development residue is less likely to occur.

[0038] As component (B) other than bisphenol-type (meth)acrylate, from the viewpoint of improving the flexibility of the cured product (cured film), it may further contain at least one polyalkylene glycol di(meth)acrylate having at least one of a (poly)oxyethylene chain and a (poly)oxypropylene chain in its molecule, or it may further contain a polyalkylene glycol di(meth)acrylate having both a (poly)oxyethylene chain and a (poly)oxypropylene chain in its molecule. Examples of the above polyalkylene glycol di(meth)acrylate include FA-023M (manufactured by Resonaq Corporation, trade name), FA-024M (manufactured by Resonaq Corporation, trade name), and NK ester HEMA-9P (manufactured by Shin Nakamura Chemical Co., Ltd., trade name). These may be used individually or in combination of two or more.

[0039] The content of polyalkylene glycol di(meth)acrylate may be 2 to 40% by mass, 3 to 30% by mass, or 5 to 20% by mass, based on the total amount of component (B).

[0040] Other components (B) besides those mentioned above may include nonylphenoxypolyethylene oxyacrylate, phthalate compounds, (meth)acrylic acid polyol esters, (meth)acrylic acid alkyl esters, etc. In particular, from the viewpoint of improving resolution, adhesion, resist shape, and peelability after curing in a balanced manner, component (B) may contain at least one selected from nonylphenoxypolyethylene oxyacrylate and phthalate compounds. However, since the refractive index of these compounds is relatively low, from the viewpoint of improving resolution, their content may be 5 to 50% by mass, 5 to 40% by mass, or 10 to 30% by mass, based on the total amount of component (B).

[0041] Examples of nonylphenoxypolyethylene oxyacrylates include nonylphenoxytriethylene oxyacrylate, nonylphenoxytetraethylene oxyacrylate, nonylphenoxypentaethylene oxyacrylate, nonylphenoxyhexaethylene oxyacrylate, nonylphenoxyheptaethylene oxyacrylate, nonylphenoxyoctaethylene oxyacrylate, nonylphenoxynonaethylene oxyacrylate, nonylphenoxydecaethylene oxyacrylate, and nonylphenoxyundaethylene oxyacrylate.

[0042] Examples of phthalate compounds include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-o-phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, among which γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate may be used. γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate is commercially available as FA-MECH (manufactured by Resonaq Corporation, trade name).

[0043] From the viewpoint of improving sensitivity and reducing streaking, component (B) may contain (meth)acrylic acid polyol. Examples of (meth)acrylic acid polyol esters include trimethylolpropane polyethoxytri(meth)acrylate, trimethylolpropane polypropoxytri(meth)acrylate, trimethylolpropane polybutoxytri(meth)acrylate, trimethylolpropane polyethoxypolypropoxytri(meth)acrylate, trimethylolethane polyethoxytri(meth)acrylate, trimethylolethane polypropoxytri(meth)acrylate, trimethylolethane polybutoxytri(meth)acrylate, trimethylolethane poly Examples include xypolypropoxytri(meth)acrylate, pentaerythritol polyethoxytri(meth)acrylate, pentaerythritol polypropoxytri(meth)acrylate, pentaerythritol polybutoxytri(meth)acrylate, pentaerythritol polyethoxypolypropoxytri(meth)acrylate, glyceryl polyethoxytri(meth)acrylate, glyceryl polypropoxytri(meth)acrylate, glyceryl polybutoxytri(meth)acrylate, and glyceryl polyethoxypolypropoxytri(meth)acrylate.

[0044] The content of component (B) is preferably 20 to 60 parts by mass, more preferably 30 to 55 parts by mass, and even more preferably 35 to 50 parts by mass, based on 100 parts by mass of the total amount of components (A) and (B). When the content of component (B) is within this range, the photosensitive resin composition exhibits better resolution, adhesion, resist base formation, as well as improved photosensitivity and coating properties.

[0045] [Photopolymerization initiator (C)] The photopolymerization initiator (C) includes a hexaarylbiimidazole compound (C1) (HABI(C1)) having an alkoxy group with three or more carbon atoms in its molecular structure. In HABI(C1), the two imidazole rings can be bonded, for example, by the nitrogen atom at position 1 and the carbon atom at position 2. Specifically, the nitrogen atom at position 1 of one imidazole ring may be bonded to the carbon atom at position 2 of the other imidazole ring, or the nitrogen atom at position 1 of one imidazole ring may be bonded to the carbon atom at position 4 or 5 of the other imidazole ring. The position numbers of the imidazole rings are as follows.

[0046]

[0047] The six aryl groups in HABI(C1) are bonded to the carbon atoms at positions 2, 4, and 5.

[0048] Regarding the alkoxy group having 3 or more carbon atoms in HABI(C1), the number of carbon atoms in the alkoxy group is not particularly limited as long as it is 3 or more, but it is preferable that it be in the range of 3 to 10, as this results in a photosensitive resin composition with even better photosensitivity and resolution during resist pattern formation, and also improves the solvent solubility of HABI(C1). Furthermore, it is more preferable that it be in the range of 3 to 8, as this provides an even better balance between the photosensitivity and resolution of the photosensitive resin composition and the solvent solubility of HABI(C1). The carbon chain of the alkoxy group may be linear or have a branched structure. Among these, it is preferable that it be linear, as this improves the solvent solubility of HABI(C1). Specific examples of alkoxy groups include n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, and the like.

[0049] In HABI(C1), alkoxy groups having three or more carbon atoms are preferably present as substituents on aryl groups bonded to the carbon atoms at positions 2, 4, and 5 of the imidazole. The number of alkoxy groups having three or more carbon atoms present on a single aryl group is not particularly limited, but may be in the range of 0 or 1 to 3, or 0, 1, or 2, or 0 or 1. The number of alkoxy groups having three or more carbon atoms in HABI(C1) is not particularly limited, but may be, for example, 6 or less per molecule, or 3 or less. Among these, it is preferably in the range of 1 to 3, and particularly preferably 2.

[0050] When HABI(C1) has 2 to 6 alkoxy groups with 3 or more carbon atoms in a single molecule, they may all be substituted on different aryl groups, or some or all may be substituted on the same aryl group. In particular, from the viewpoint of the stability of the radical species generated during the reaction process, it is preferable that they are all substituted on different aryl groups. When HABI(C1) has 2 alkoxy groups with 3 or more carbon atoms in a single molecule, these are preferably substituents on an aryl group bonded to the 2-position of imidazole.

[0051] The substitution position of the alkoxy group on each aryl group is not particularly limited and may be at the ortho, meta, or para position relative to the bond position with the imidazole ring. In particular, from the viewpoint of photosensitivity, it is preferable that the alkoxy group is substituted at the ortho position relative to the bond position with the imidazole ring.

[0052] HABI(C1) may have substituents on the aryl group other than alkoxy groups having 3 or more carbon atoms. Examples of other substituents include hydrocarbon groups having 1 to 6 carbon atoms, methoxy groups, ethoxy groups, etc. The ratio of alkoxy groups having 3 or more carbon atoms to the total number of substituents on the aryl group may be 60% or more, 80% or more, 90% or more, or 100%. From the viewpoint of obtaining a photosensitive resin composition with even better photosensitivity and resolution during resist pattern formation, HABI(C1) may be a compound having only alkoxy groups having 3 or more carbon atoms as substituents on the aryl group.

[0053] HABI(C1) may not contain halogen atoms in its molecular structure. In this case, depending on what other components are used in the photosensitive resin composition, it becomes possible to make the photosensitive resin composition halogen-free or low in halogens.

[0054] HABI(C1) may contain, for example, a compound represented by the following general formula (1).

[0055]

[0056] [In general formula (1), each X independently represents either a hydrogen atom or an alkoxy group with a carbon chain of 3 to 8 atoms, and at least two of the multiple X groups are alkoxy groups.]

[0057] The alkoxy group may be, for example, an alkoxy group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Specific examples of alkoxy groups having 1 to 8 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, and n-octyloxy groups.

[0058] The compound represented by the above general formula (1) may more specifically be the compound represented by the following general formula (1-1).

[0059]

[0060] [In general formula (1-1), X is independently an alkoxy group having 3 or more carbon atoms.]

[0061] In general formula (1-1), X is independently an alkoxy group having 3 or more carbon atoms. X may independently be an alkoxy group having 3 to 10 carbon atoms, or an alkoxy group having 3 to 8 carbon atoms. Specific examples of alkoxy groups having 3 to 10 carbon atoms include n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, etc.

[0062] The photopolymerization initiator (C) may include other photopolymerization initiators other than HABI(C1). When using other photopolymerization initiators, one type may be used alone, or two or more types may be used in combination. Specific examples of other photopolymerization initiators include, for example, hydrogen abstraction type radical generators such as benzophenone compounds, thioxanthone compounds, fluorenone compounds, and acridine compounds; and intramolecular cleavage type radical generators such as benzyl ketal compounds, α-aminoalkylphenone compounds, α-hydroxyalkylphenone compounds, α-hydroxyacetophenone compounds, and acylphosphine oxide compounds.

[0063] The ratio of HABI(C1) to the total mass of photopolymerization initiators (C) may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass. Furthermore, the total amount of photopolymerization initiators (C) added to the photosensitive resin composition may be 0.5% by mass or more, 1% by mass or more, or 3% by mass or more, relative to the total mass of the binder polymer (A) and the photopolymerizable compound (B). It may also be 15% by mass or less, 10% by mass or less, or 8% by mass or less. The total amount of photopolymerization initiators (C) added may be, for example, in the range of 0.5 to 15% by mass relative to the total mass of the binder polymer (A) and the photopolymerizable compound (B).

[0064] In addition to a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), the photosensitizing dye (D), an amine compound (E), and other components of one embodiment of the photosensitive resin composition may also contain other components.

[0065] [Sensitizing dye (D)] The photosensitive resin composition of this embodiment may contain at least one sensitizing dye (D). Examples of sensitizing dyes (D) include dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, xanthone compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, triazine compounds, thiophene compounds, naphthalimide compounds, triarylamine compounds, and aminoacridine compounds. These can be used alone or in combination of two or more.

[0066] In particular, when exposing a photosensitive resin composition layer using active light in the range of 340 to 430 nm, from the viewpoint of sensitivity and adhesion, the sensitizing dye (D) preferably contains at least one sensitizing dye selected from the group consisting of dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, triarylamine compounds, thioxanthone compounds, and aminoacridin compounds. More preferably, it contains at least one selected from the group consisting of dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, and triarylamine compounds, and even more preferably, it contains at least one pyrazoline compound.

[0067] The content of the sensitizing dye (D) in the photosensitive resin composition is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, and even more preferably 0.02 to 3 parts by mass, per 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B). When the content is 0.01 parts by mass or more, sensitivity and resolution tend to be easily obtained, and when it is 10 parts by mass or less, a sufficiently good resist shape tends to be easily obtained.

[0068] The pyrazoline compound is preferably at least one selected from the group consisting of compounds represented by the following general formula (6) and compounds represented by the following general formula (7).

[0069]

[0070] In general formula (6), R ８ ~R １０ Each of these independently represents a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a halogen atom. Furthermore, each of c, d, and e independently represents an integer from 0 to 5, and the sum of c, d, and e is from 1 to 6. When the sum of c, d, and e is 2 or more, there are multiple R ８ ~R １０ They may be the same or different from each other.

[0071] In general formula (6), R ８ ~R １０ At least one of these is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxy group having 1 to 10 carbon atoms; more preferably a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a phenyl group; and even more preferably a tert-butyl group, an isopropyl group, a methoxy group, or an ethoxy group.

[0072] The pyrazoline compound represented by general formula (6) can be used without particular limitations, but specifically, 1-phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 1-phenyl-3-(4-tert-butylstyryl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(3,4-dimethoxy Examples of pyrazoline compounds corresponding to c=0 in the above general formula (6) include tyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, and 1-phenyl-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline.

[0073]

[0074] In general formula (7), R １１ ~R １３ Each of these independently represents a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, a halogen atom, or a phenyl group. Furthermore, each of f, g, and h independently represents an integer from 0 to 5, and the sum of f, g, and h is from 1 to 6. When the sum of f, g, and h is 2 or more, there are multiple R １１ ~R １３ They may be the same or different from each other.

[0075] In general formula (7), R １１ ~R １３At least one of these is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a phenyl group; more preferably a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a phenyl group; and even more preferably a tert-butyl group, an isopropyl group, a methoxy group, an ethoxy group, or a phenyl group.

[0076] Furthermore, the pyrazoline compound represented by general formula (7) can be used without particular limitation, but includes 1-phenyl-3,5-bis(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3,5-bis(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(4-methoxyphenyl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-tert-butylphenyl)-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(4-tert-butylphenyl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-tert-butylphenyl)-5-(4-isopropylphenyl)-pyrazoline, 1-phenyl-3-(4-methoxyphenyl)-5-(4-isopropylphenyl)-pyrazoline, 1,5- Diphenyl-3-(4-tert-butylphenyl)-pyrazoline, 1,3-diphenyl-5-(4-tert-butylphenyl)-pyrazoline, 1,5-diphenyl-3-(4-isopropylphenyl)-pyrazoline, 1,3-diphenyl-5-(4-isopropylphenyl)-pyrazoline, 1,5-diphenyl-3-(4-methoxyphenyl)-pyrazoline, 1,3-diphenyl-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl Pyrazoline compounds corresponding to d=0 in the above general formula (8), such as Lu-3,5-bis(4-tert-butylphenyl)-pyrazolin and 1,5-diphenyl-3-(4-tert-butylphenyl)-pyrazolin; and in the above general formula (7), such as 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)-pyrazolin and 1-phenyl-3-(4-biphenyl)-5-(4-tert-octylphenyl)-pyrazolin, g=1, R １２ Examples include pyrazoline compounds, which have a phenyl group.

[0077] The anthracene compound preferably includes a compound represented by the following general formula (8).

[0078]

[0079] In general formula (8), R １４ and R１５ Each of these independently represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, a phenyl group, a benzyl group, an alkanoyl group having 2 to 12 carbon atoms, or a benzoyl group. ２２ ~R ２９ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxycarbonyl group having 2 to 6 carbon atoms, or a benzoyl group.

[0080] R in general formula (8) １４ and R １５ Examples include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. １４ and R １５ Examples of such combinations include combinations of ethyl groups, combinations of propyl groups, and combinations of butyl groups.

[0081] R １６ ~R ２３ Examples include hydrogen atoms, methyl groups, ethyl groups, propyl groups, butyl groups, pentyl groups, hexyl groups, propenyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, ethoxycarbonyl groups, hydroxyethoxycarbonyl groups, and phenoxy groups. Combinations of R19 to R26 include: all of them being hydrogen atoms; one of them being a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, ethoxycarbonyl group, hydroxyethoxycarbonyl group, or phenoxy group, with all the others being hydrogen atoms; and any two of them being groups independently selected from the group consisting of methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, ethoxycarbonyl group, hydroxyethoxycarbonyl group, and phenoxy group, with all the others being hydrogen atoms, etc.

[0082] R １４ and R １５Each of these is preferably an alkyl group having 1 to 4 carbon atoms. １６ , R １７ , R １８ , R １９ , R ２０ , R ２１ , R ２２ , and R ２３ It is preferable that it is a hydrogen atom.

[0083] Examples of compounds represented by general formula (8) include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 9,10-dibutoxyanthracene.

[0084] The triarylamine compound is preferably at least one compound represented by the following general formula (9).

[0085]

[0086] In general formula (9), R ２４ , R ２５ and R ２６ Each independently represents an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. i, j, and k are integers from 0 to 5 selected such that the value of i + j + k is 1 or greater. Note that if i is 2 or greater, there are multiple R ２４ They may be the same or different, and if j is 2 or greater, there may be multiple R ２５ The elements may be the same or different, and if k is 2 or greater, there may be multiple R elements. ２６ They may be the same or different. In general formula (9), R ２４ , R ２５ and R ２６ It is preferable that it is a hydrogen atom.

[0087] [Amine Compound (E)] The photosensitive resin composition preferably contains at least one amine compound (E). Examples of amine compounds (E) include bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, and leucocrystal violet. These can be used individually or in combination of two or more.

[0088] When the photosensitive resin composition contains an amine compound (E), its content is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B). When the content is 0.01 parts by mass or more, sufficient sensitivity tends to be easily obtained. When it is 10 parts by mass or less, the precipitation of excess amine compound as foreign matter in the photosensitive element tends to be suppressed.

[0089] [Other Components] The photosensitive resin composition may optionally contain a photopolymerizable compound having at least one cationically polymerizable cyclic ether group in its molecule (such as an oxetane compound), a cationic polymerization initiator, dyes such as malachite green, Victoria Pure Blue, Brilliant Green, and methyl violet, photochromicants such as tribromophenylsulfone, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline, thermal color inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoamers, flame retardants, stabilizers, adhesion promoters, leveling agents, release accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. These may be used individually or in combination of two or more. If the photosensitive resin composition contains other components, their content is preferably about 0.01 to 20 parts by mass each, based on 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B).

[0090] [Solution of Photosensitive Resin Composition] The photosensitive resin composition may further contain at least one organic solvent. Examples of organic solvents include alcohol solvents such as methanol and ethanol; ketone solvents such as acetone and methyl ethyl ketone; glycol ether solvents such as methyl cellosolve, ethyl cellosolve, and propylene glycol monomethyl ether; aromatic hydrocarbon solvents such as toluene; and aprotic polar solvents such as N,N-dimethylformamide. These may be used individually or in mixtures of two or more. The content of the organic solvent in the photosensitive resin composition can be appropriately selected depending on the purpose. For example, it can be used as a solution with a solid content of about 30% to 60% by mass (hereinafter, the photosensitive resin composition containing the organic solvent will also be referred to as the "coating solution").

[0091] [Uses of the Photosensitive Resin Composition] The specific uses of the photosensitive resin composition of one embodiment are not particularly limited, but it can be used as a dry film-type photosensitive element. The photosensitive element can be used, for example, as a material for forming resist patterns. Alternatively, the photosensitive resin composition can be used as is as a liquid negative-type resist material.

[0092] [Photosensitive Element] The photosensitive element of one embodiment comprises a support film and a photosensitive resin composition layer provided on the support film, wherein the photosensitive resin composition layer contains the photosensitive resin composition described above. The photosensitive resin composition layer may be a coating of the photosensitive resin composition. Note that the coating of the photosensitive resin composition is in an uncured state. The photosensitive element may have other layers such as a protective film as needed.

[0093] An embodiment of a photosensitive element is shown. The photosensitive element may consist of a support film, a photosensitive resin composition layer which is a coating of a photosensitive resin composition, and a protective film, laminated in this order. The photosensitive element can be obtained, for example, as follows: A coating solution which is a photosensitive resin composition containing an organic solvent is applied to the support film to form a coating layer, and this is dried to form a photosensitive resin composition layer. Then, the side of the photosensitive resin composition layer opposite to the support film is covered with a protective film to obtain a photosensitive element comprising a support film, a photosensitive resin composition layer laminated on the support film, and a protective film laminated on the photosensitive resin composition layer. The photosensitive element does not necessarily have to include a protective film.

[0094] As the support film, polymer films with heat resistance and solvent resistance, such as polyethylene terephthalate, polyester, polypropylene, and polyethylene, can be used.

[0095] The thickness of the support film (polymer film) is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm, and even more preferably 5 μm to 30 μm. A support film thickness of 1 μm or more suppresses tearing of the support film when it is peeled off. A thickness of 100 μm or less suppresses a decrease in resolution.

[0096] The protective film is preferably one in which the adhesive strength to the photosensitive resin composition layer is less than the adhesive strength to the photosensitive resin composition layer of the support film. Furthermore, a low-fish-eye film is preferred. Here, "fish-eye" refers to the incorporation of foreign matter, undissolved material, oxidatively degraded material, etc., into the film during the manufacturing process by thermal melting, kneading, extrusion, biaxial stretching, casting, etc. In other words, "low-fish-eye" means that there is a small amount of the above-mentioned foreign matter, etc., in the film.

[0097] Specifically, the protective film can be a polymer film having heat resistance and solvent resistance, such as polyester (e.g., polyethylene terephthalate), polypropylene, or polyethylene. Commercially available examples include Alphan MA-410 and E-200 from Oji Paper Co., Ltd., polypropylene films from Shin-Etsu Film Co., Ltd., and polyethylene terephthalate films from the PS series such as PS-25 from Teijin Limited. The protective film 6 may be the same as the support film 2.

[0098] The thickness of the protective film is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm, even more preferably 5 μm to 30 μm, and particularly preferably 15 μm to 30 μm. When the thickness of the protective film is 1 μm or more, tearing of the protective film can be suppressed when laminating the photosensitive resin layer and support film onto the substrate while peeling off the protective film. When the thickness is 100 μm or less, it is excellent in terms of handling and cost.

[0099] A photosensitive element according to one embodiment can be manufactured specifically, for example, as follows: It can be manufactured by a manufacturing method that includes the steps of: preparing a coating solution containing a binder polymer (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and an organic solvent; applying the coating solution onto a support film to form a coating layer; and drying the coating layer to form a photosensitive resin composition layer.

[0100] The photosensitive resin composition solution can be applied to the support film by known methods such as roll coating, comma coating, gravure coating, air knife coating, die coating, and bar coating.

[0101] The drying of the above-mentioned coating layer is not particularly limited as long as at least a portion of the organic solvent can be removed from the coating layer. It is preferable to dry it at 70°C to 150°C for about 5 to 30 minutes. After drying, the amount of residual organic solvent in the photosensitive resin composition layer is preferably 2% by mass or less, from the viewpoint of preventing the diffusion of the organic solvent in subsequent processes.

[0102] The transmittance of the 15 μm photosensitive resin composition layer to ultraviolet light is preferably 10% to 100%, more preferably 40% to 90%, and particularly preferably 60% to 80% for ultraviolet light in the wavelength range of 350 nm to 420 nm. When this transmittance is 50% or higher, it tends to be easier to obtain sufficient pattern moldability. When it is 90% or lower, it tends to be easier to obtain sufficient resolution. The above transmittance can be measured using a UV spectrometer. An example of a UV spectrometer is the Hitachi 228A W-beam spectrophotometer manufactured by Hitachi, Ltd.

[0103] The photosensitive element may further have intermediate layers such as a cushion layer, adhesive layer, light-absorbing layer, or gas barrier layer. As these intermediate layers, for example, the intermediate layer described in Japanese Patent Application Publication No. 2006-098982 can also be applied in this embodiment.

[0104] The form of the photosensitive element is not particularly limited. For example, it may be in the form of a sheet, or it may be wound in a roll on a core. When wound in a roll, it is preferable to wind it so that the support film is on the outside. Examples of cores include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer). It is preferable to install an end separator on the end face of the roll of photosensitive element obtained in this way for the standpoint of end face protection, and it is preferable to install a moisture-proof end face separator for the standpoint of edge fusion resistance. As for the packaging method, it is preferable to wrap it in a black sheet with low moisture permeability.

[0105] The photosensitive element of one embodiment can be suitably used, for example, as a material for forming a resist pattern.

[0106] [Method for forming a resist pattern] A method for forming a resist pattern according to one embodiment includes a lamination step of laminating a photosensitive resin composition layer of a photosensitive element on a substrate, an exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with active light to photo-cure the exposed portion, and a development step of removing the portion of the photosensitive resin composition layer other than the exposed portion. The method for forming a resist pattern may further include other steps as needed.

[0107] (i) Lamination process First, a circuit-forming substrate comprising an insulating layer and a conductive layer formed on the insulating layer can be used as the substrate on which the photosensitive resin composition layer is laminated. Lamination of the photosensitive resin composition layer onto the substrate is performed, for example, if the photosensitive element has a protective film 6, by removing the protective film and then pressing the photosensitive resin composition layer of the photosensitive element onto the substrate while heating it. This results in a laminate in which the substrate, the photosensitive resin composition layer and the support film are laminated in this order.

[0108] This lamination process is preferably carried out under reduced pressure from the viewpoint of adhesion and conformability. Heating of at least one of the photosensitive resin composition layer and the substrate during bonding is preferably carried out at a temperature of 70°C to 130°C, and bonding is preferably carried out at a pressure of about 0.1 MPa to 1.0 MPa (about 1 kgf / cm² to 10 kgf / cm²). These conditions are not particularly limited and can be appropriately selected as needed. Note that if the photosensitive resin composition layer is heated to 70°C to 130°C, it is not necessary to preheat the substrate beforehand. Preheating the substrate can further improve adhesion and conformability.

[0109] (ii) Exposure process In the exposure process, an active light is irradiated onto at least a portion of the photosensitive resin layer formed on the substrate as described above, so that the exposed area irradiated with the active light is photocured and a latent image is formed. At this time, if the support film present on the photosensitive resin composition layer is transparent to the active light, the active light can be irradiated through the support film. On the other hand, if the support film is light-shielding to the active light, the active light is irradiated onto the photosensitive resin composition layer after the support film is removed.

[0110] One exposure method is to irradiate the image with active light through a negative or positive mask pattern called artwork (mask exposure method). Alternatively, methods such as LDI (Laser Direct Imaging) exposure or projection exposure may be used to irradiate the image with active light.

[0111] There are no particular restrictions on the light source for the active light, and known light sources can be used. For example, carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid-state lasers such as YAG lasers, semiconductor lasers, and gallium nitride-based blue-violet lasers that effectively emit ultraviolet light, visible light, etc. can be used.

[0112] From the viewpoint of more reliably obtaining the effects of the present invention, the wavelength of the active light (exposure wavelength) is preferably in the range of 340 nm to 430 nm, and more preferably in the range of 350 nm to 420 nm.

[0113] (iii) Development Process In the development process, the parts of the photosensitive resin composition layer other than the exposed areas are removed from the substrate by the development process, thereby forming a resist pattern on the substrate, which is a cured product of the photosensitive resin composition layer. If a support film or optical adjustment layer is present on the photosensitive resin composition layer, these are removed before removing the unexposed areas (development). There are two types of development processes: wet development and dry development, but wet development is widely used.

[0114] In wet development, development is carried out using a developer solution corresponding to the photosensitive resin composition and a known development method. Development methods include the dip method, battle method, spray method, brushing, slapping, scraping, and agitation immersion, with the high-pressure spray method being the most suitable from the viewpoint of improving resolution. Two or more of these methods may also be combined for development.

[0115] The developer is selected appropriately according to the composition of the photosensitive resin composition. Examples of developers include alkaline aqueous solutions and organic solvent-based developers.

[0116] Alkaline aqueous solutions are safe, stable, and easy to handle when used as developing solutions. Suitable bases for alkaline aqueous solutions include alkali hydroxides such as lithium, sodium, or potassium hydroxides; alkali carbonates such as lithium, sodium, potassium, or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate.

[0117] Preferred alkaline aqueous solutions for development include dilute solutions of 0.1% to 5% by mass sodium carbonate, 0.1% to 5% by mass potassium carbonate, 0.1% to 5% by mass sodium hydroxide, and 0.1% to 5% by mass sodium tetraborate. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11. The temperature is adjusted according to the alkaline developability of the photosensitive resin composition layer. Surface surfactants, defoamers, and small amounts of organic solvents to promote development may be added to the alkaline aqueous solution.

[0118] Examples of organic solvent-based developers include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. To prevent ignition, it is preferable to add water in an amount of 1 to 20% by mass to these organic solvents.

[0119] The above method for forming a resist pattern may further include a step of further curing the resist pattern by removing the unexposed areas and, if necessary, heating to about 60°C to 250°C or exposure to about 0.2 J / cm² to 10 J / cm².

[0120] [Method for Manufacturing Printed Wiring Boards] The method for manufacturing printed wiring boards according to this disclosure includes a step of etching or plating a substrate on which a resist pattern has been formed by the resist pattern formation method described above to form a conductor pattern. The method for manufacturing printed wiring boards may also include other steps, such as a resist removal step, as necessary. The etching or plating of the substrate is performed on the conductor layer of the substrate, etc., using the formed resist pattern as a mask.

[0121] In the etching process, a resist pattern formed on the substrate is used as a mask to etch away the conductive layer of the substrate that is not covered by the resist, thereby forming a conductive pattern. The etching method is appropriately selected depending on the conductive layer to be removed. Examples of etching solutions include cupric chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide etching solution. Among these, ferric chloride solution is preferred because it has a good etch factor.

[0122] On the other hand, in the plating process, a resist pattern formed on the substrate is used as a mask, and copper and solder are plated onto the conductive layer of the substrate that is not covered by the resist. After the plating process, the resist pattern is removed, and the conductive layer that was covered by this resist pattern is further etched to form a conductive pattern. The plating method may be electrolytic plating or electroless plating. Examples of plating methods include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-slow solder plating, nickel plating such as Watt bath (nickel sulfate-nickel chloride) plating and nickel sulfamate, and gold plating such as hard gold plating and soft gold plating.

[0123] After the etching and plating processes described above, the resist pattern on the substrate is removed (peeled off). The resist pattern can be removed, for example, using an aqueous solution that is even more strongly alkaline than the alkaline aqueous solution used in the development process. Examples of such strongly alkaline aqueous solutions include 1 to 10% by mass sodium hydroxide aqueous solution and 1 to 10% by mass potassium hydroxide aqueous solution. In particular, it is preferable to use a 1 to 10% by mass sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, and it is more preferable to use a 1 to 5% by mass sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution. Methods for peeling off the resist pattern include immersion methods and spray methods, which may be used alone or in combination.

[0124] After plating and removing the resist pattern, the desired printed circuit board can be manufactured by further etching the conductive layer covered with the resist to form a conductive pattern. The etching method is appropriately selected depending on the conductive layer to be removed. For example, the etching solution described above can be applied.

[0125] The method for manufacturing printed circuit boards described herein is applicable not only to the manufacture of single-layer printed circuit boards but also to the manufacture of multi-layer printed circuit boards, and is also applicable to the manufacture of printed circuit boards having small-diameter through-holes, etc.

[0126] Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> A photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaarylbiimidazole compound (C1) having an alkoxy group with 3 or more carbon atoms in its molecular structure.

[0127] <2> The photosensitive resin composition according to <1>, wherein the hexaarylbiimidazole compound (C1) has an alkoxy group having 3 to 8 carbon atoms in its molecular structure.

[0128] <3> The photosensitive resin composition according to <1> or <2>, wherein the hexaarylbiimidazole compound (C1) comprises a compound represented by the following general formula (1).

[0129]

[0130] [In general formula (1), each X independently represents either a hydrogen atom or an alkoxy group with a carbon chain of 3 to 8 atoms, and at least two of the multiple X groups are alkoxy groups.]

[0131] <4> A photosensitive resin composition according to any one of <1> to <3>, further comprising an amine compound.

[0132] <5> The photosensitive resin composition according to <4>, wherein the amine compound comprises tris(4-dimethylaminophenyl)methane (leucocrystal violet).

[0133] <6> A photosensitive element comprising a support film and a photosensitive resin composition layer formed on the support film, the photosensitive resin composition according to any one of <1> to <5>.

[0134] <7> A photosensitive element according to <6> above, which is a material for forming a resist pattern.

[0135] <8> A method for forming a resist pattern, comprising: a lamination step of laminating a photosensitive resin composition layer containing any one of <1> to <5> on a substrate; an exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an active light to photo-cure the exposed portion; and a development step of removing the portion of the photosensitive resin composition layer other than the exposed portion from the substrate on which the photosensitive resin composition layer is laminated.

[0136] <9> A method for manufacturing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the resist pattern formation method described in <8> above to form a conductor pattern.

[0137] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0138] Measurement Method for Weight-Average Molecular Weight (Mw) and Number-Average Molecular Weight (Mn): The weight-average molecular weight and number-average molecular weight were calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The GPC conditions are shown below.

[0139] Detector: L-2490 RI (manufactured by Hitachi, Ltd.) Column: Gelpack GL-R440, Gelpack GL-R450, and Gelpack GL-R400M (manufactured by Resonaq Techno Service Co., Ltd.) Eluent: Tetrahydrofuran Sample concentration: 5 mg / 1 mL Injection volume: 200 μL Flow rate: 2.05 mL / min Measurement temperature: 40°C

[0140] Examples 1-5 and Comparative Example 1 [Production of Photosensitive Resin Composition] A photosensitive resin composition was produced by blending and mixing each component in the proportions shown in Table 1 below. For components other than the solvent in Table 1, the amounts are calculated on a solid content basis for components that are solutions. The obtained photosensitive resin composition was evaluated according to the following procedure. The results are shown in Table 2.

[0141] The details of each component in Table 1 are as follows: • Binder polymer (A-1): Methylpropylene glycol / toluene solution of copolymer of methacrylic acid / styrene / 2-hydroxyethyl methacrylate / benzyl methacrylate (mass ratio: 27 / 50 / 3 / 20, weight-average molecular weight: 35000) • Radical polymerizable compound (B-1): Polyethylene oxide modified compound of bisphenol A dimethacrylate, the average total number of ethylene oxide groups in one molecule is 10 (FA-321M, manufactured by Resona Corporation) • Radical polymerizable compound (B-2): Polyethylene oxide modified compound of bisphenol A dimethacrylate, the average total number of ethylene oxide groups in one molecule is 2.6 (Light Ester BP-2EM, manufactured by Kyoeisha Chemical Co., Ltd.) • Radical polymerizable compound (B-3): Polyalkylene glycol di(meth)acrylate represented by the following general formula (10), the average sum of l and n is 12, and the average value of m is 6 (FA-024M, manufactured by Resona Corporation)

[0142]

[0143] HABI(C1-1): Compounds in which X is an n-propoxy group in the general formula (1-1) below. HABI(C1-2): Compounds in which X is an n-butoxy group in the general formula (1-1) below. HABI(C1-3): Compounds in which X is an n-pentyloxy group in the general formula (1-1) below. HABI(C1-4): Compounds in which X is an n-hexyloxy group in the general formula (1-1) below. HABI(C1-5): Compounds in which X is an n-octyloxy group in the general formula (1-1) below. HABI(C1'-1): Compounds in which X is a chloro group in the general formula (1-1) below.

[0144]

[0145] • Sensitizing dye (D-1): 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline (manufactured by Nippon Chemical Industries, Ltd., "PZ-501D") • Amine compound (E-1): Leucocrystal violet (tris[4-(dimethylamino)phenyl]methane) (Yamada Chemical Co., Ltd.) • Polymerization inhibitor (F-1): DIC Corporation, "Q-TBC-5P", tertiary butylcatechol • Polymerization inhibitor (F-2): 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (manufactured by Adeka Corporation, "LA-7RD") • Adhesion granulator (G-1): Mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (manufactured by Sanwa Chemicals, Ltd., "Q-SF-808H") • Dye (H-1): Malachite green (manufactured by Osaka Organic Chemical Industry Co., Ltd.) • Solvent (I-1): Toluene • Solvent (I-2): Methanol • Solvent (I-3): Acetone

[0146]

[0147] [Manufacturing of Photosensitive Element] The photosensitive resin composition obtained above was applied onto a support film (*1). It was dried in a hot air convection dryer at 80°C and 105°C to form a photosensitive resin composition layer with a thickness of 15 μm. Subsequently, a protective film (*2) was laminated onto the photosensitive resin composition layer to obtain a photosensitive element. Support film (*1): 16 μm thick polyethylene terephthalate film (Toray Industries, Inc. "FS-31") Protective film (*2): 28 μm thick polyethylene film (Tamapoly Co., Ltd., product name "NF-15A")

[0148] [Measurement of shortest development time] While peeling off the protective film of the photosensitive element, the photosensitive resin composition layer of the photosensitive element was placed in contact with the copper surface of the substrate (*3) and laminated to obtain a laminated material 1. Lamination was performed using a 110°C heat roll under the conditions of a pressing pressure of 0.4 MPa and a roll speed of 1.0 m / min. Substrate (*3): Copper sputtered onto a polyethylene terephthalate film.

[0149] Subsequently, the support film was peeled off, and this was used as a test specimen. Using a 1.0% by mass aqueous solution of sodium carbonate at 30°C, the unexposed photosensitive resin composition layer on the test specimen was spray-developed at a pressure of 0.10 MPa, and the shortest time at which the complete removal of the unexposed photosensitive resin composition layer could be visually confirmed was defined as the shortest development time.

[0150] [Measurement of exposure amount] A 41-step tablet (manufactured by Resonac Corporation) was placed on the support film of the laminate 1, and then exposed using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") with an ultra-high pressure mercury lamp (365 nm) as the light source. After peeling off the support film, development was performed using a 1.0 mass% sodium carbonate aqueous solution at 30°C with a spray pressure of 0.10 MPa for twice the minimum development time. A calibration curve for the number of remaining steps was created by changing the exposure amount, and the exposure amount at which the number of remaining steps after development of the 41-step tablet was 11 was calculated.

[0151] [Evaluation of Adhesion and Resolution] After placing glass-chromium type phototools 1 and 2 (*) on the support film of laminate 1, exposure was performed using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") with an ultra-high pressure mercury lamp (365 nm) as the light source, at an exposure amount that resulted in 11 remaining steps after development of the previously measured 41-step step tablet. The focus position was set to the upper part of the film thickness of the photosensitive resin composition layer. After peeling off the support film, development was performed using a 1.0 mass% sodium carbonate aqueous solution at 30°C with a spray pressure of 0.10 MPa for twice the minimum development time. For each phototool used, the minimum x value at which a clear resist pattern was obtained with clean removal of the space areas (unexposed areas) and no pattern distortion, meandering, or missing parts in the line areas (exposed areas) was defined as adhesion and resolution. This test was performed three times, and the average value of x was used for evaluation.

[0152] - Photo Tool 1: Line width / Space width = x / 3x (adhesion), where x is between 1 μm and 10 μm. - Photo Tool 2: Line width / Space width = 3x / x (resolution), where x is between 1 μm and 10 μm.

[0153]

[0154] As shown in Table 2, the photosensitive resin compositions of Examples 1 to 5 have higher photosensitivity compared to the photosensitive resin composition of Comparative Example 1, allowing for the formation of high-resolution resist patterns even with a small exposure.

Claims

1. A photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaarylbiimidazole compound (C1) having an alkoxy group with 3 or more carbon atoms in its molecular structure.

2. The photosensitive resin composition according to claim 1, wherein the hexaarylbiimidazole compound (C1) has an alkoxy group having 3 to 8 carbon atoms in its molecular structure.

3. The photosensitive resin composition according to claim 1, wherein the hexaarylbiimidazole compound (C1) comprises a compound represented by the following general formula (1). [In general formula (1), each X independently represents either a hydrogen atom or an alkoxy group with a carbon chain of 3 to 8 atoms, and at least two of the multiple X groups are alkoxy groups.] 4. The photosensitive resin composition according to claim 1, further comprising an amine compound.

5. The photosensitive resin composition according to claim 4, wherein the amine compound comprises tris(4-dimethylaminophenyl)methane (leucocrystal violet).

6. A photosensitive element comprising a support film and a photosensitive resin composition layer formed on the support film, the photosensitive resin composition according to any one of claims 1 to 5.

7. The photosensitive element according to claim 6, which is a material for forming a resist pattern.

8. A method for forming a resist pattern, comprising: a lamination step of laminating a photosensitive resin composition layer containing the photosensitive resin composition described in any one of claims 1 to 5 onto a substrate; an exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an active light to photo-cure the exposed portion; and a development step of removing the portion of the photosensitive resin composition layer other than the exposed portion from the substrate on which the photosensitive resin composition layer is laminated.

9. A method for manufacturing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the resist pattern formation method described in claim 8 to form a conductor pattern.

Images