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

Abstract

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

Description

Technical Field

[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 wiring board. Background Technology

[0002] In the manufacturing of printed circuit boards, photosensitive resin materials are widely used as resist materials in processes such as etching and plating. Laminated photosensitive elements, which are obtained by forming a layer of photosensitive resin material on a support film and then depositing a protective film on it, are available on the market.

[0003] The recent trend towards miniaturization of circuit patterns necessitates the development of corresponding photosensitive resin materials. Basic and important properties required of photosensitive resin materials include sufficient light sensitivity even with low exposure levels and the ability to form patterns at high resolution. Furthermore, the increasing demand for reduced environmental impact and improved workplace safety in industrial chemicals has led to a growing expectation for the development of products that do not contain halogen atoms.

[0004] Photosensitive resin materials mainly consist of free radical polymerizable compounds and photopolymerization initiators. Hexaarylbiimidazole compounds (hereinafter sometimes referred to as "HABI") containing chlorine groups are widely used as polymerization initiators. However, there are concerns about the environmental impact of these compounds due to their inclusion of halogen atoms. Research is underway to adapt HABI by substituting chlorine groups with alkoxy groups (see Patent Document 1 and Patent Document 2).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-237736 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] As mentioned above, the development of photosensitive resin compositions that do not contain halogen-free atoms has been studied, but the known HABI as described in Patent Document 1 does not meet the performance levels required recently in terms of photosensitivity and resolution.

[0010] One of the objectives of this disclosure is to provide 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 wiring board.

[0011] Technical means to solve the problem

[0012] This disclosure includes the following embodiments. However, this disclosure is not limited to these embodiments.

[0013] One embodiment relates to a photosensitive resin composition comprising an adhesive 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 having three or more carbon atoms in its molecular structure.

[0014] The effects of the invention

[0015] 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 wiring board. Detailed Implementation

[0016] The following provides a detailed description of the embodiments of this disclosure. However, this disclosure is not limited to the following embodiments.

[0017] In this disclosure, the numerical range represented by "~" indicates the range in which the values ​​recorded before and after the "~" are respectively the minimum and maximum values. In the numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range can also be replaced by the upper or lower limit of another numerical range. Furthermore, the upper or lower limit of the numerical ranges described in this disclosure can also be replaced by the values ​​shown in the embodiments.

[0018] Unless otherwise specified, the photosensitive resin compositions disclosed herein may also contain one or more substances that correspond to each component.

[0019] In this disclosure, when a photosensitive resin composition contains multiple substances that correspond to a certain component, unless otherwise specified, the content of said component in the photosensitive resin composition refers to the total amount of said multiple substances present in the photosensitive resin composition.

[0020] In this disclosure, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid. (Meth)acrylate refers to at least one of acrylate and its corresponding methacrylate. (Methacryl)acryloyl refers to at least one of acryloyl and methacryloyl.

[0021] In this disclosure, unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​obtained by gel permeation chromatography (GPC) and converted from calibration curves using standard polystyrene. The conditions for GPC are shown below.

[0022] Detector: L-2490 RI (manufactured by Hitachi, Ltd.)

[0023] Tube Columns: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (manufactured by Resonac Techno Service Co., Ltd.)

[0024] Eluent: Tetrahydrofuran

[0025] Sample concentration: 5 mg / 1 mL

[0026] Injection volume: 200μL

[0027] Flow rate: 2.05 mL / min

[0028] Measurement temperature: 40℃

[0029] As an embodiment of the present disclosure, the photosensitive resin composition is a photosensitive resin composition containing an adhesive polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaaryl biimidazole compound (C1) having an alkoxy group having three or more carbon atoms in its molecular structure.

[0030] Hexaaryl biimidazole compounds (C1) with alkoxy groups having three or more carbon atoms in their molecular structure (hereinafter sometimes referred to as "HABI(C1)") exhibit superior photosensitivity compared to HABI compounds with halogen atoms in their molecular structure. Specifically, when an embodiment of the photosensitive resin composition is used as a resist patterning material, the required exposure amount can be reduced without increasing the amount of photopolymerization initiator (C). While not limited to any specific theory, this is based on considerations such as the possibility that the absorbance of the wavelength of light used in resist patterning in HABI(C1) is higher than that in HABI compounds with halogen atoms.

[0031] Furthermore, compared to HABI with alkoxy groups having fewer than 3 carbon atoms, HABI (C1) has an increased number of carbon atoms in its alkoxy groups, thereby improving the solubility of components other than the photopolymerization initiator (C) in the photosensitive resin composition and making it suitable for finer regions. Specifically, it is also suitable for applications with a resolution range of 4 μm to 5 μm.

[0032] [Adhesive Polymer (A)]

[0033] The photosensitive resin composition of this embodiment further improves resolution and adhesion by containing an adhesive polymer.

[0034] (A) The component may also include an adhesive polymer having at least one of the following general formulas: (2), (3), (4), and (5). This further improves the resolution and adhesion of the photosensitive resin composition. Furthermore, it further shortens the development time and peeling time.

[0035] [Chemistry 1]

[0036]

[0037] In equation (2), R 1 R represents a hydrogen atom or a methyl group. 2 Represents hydrogen atoms, alkyl groups with 1 to 3 carbon atoms, alkoxy groups with 1 to 3 carbon atoms, hydroxyl groups, or halogen atoms, and multiple R atoms. 2 They can be the same or different.

[0038] [Chemistry 2]

[0039]

[0040] In equation (3), R 3 It represents a hydrogen atom or a methyl group.

[0041] [Chemistry 3]

[0042]

[0043] In equation (4), R 4 R represents a hydrogen atom or a methyl group. 5 The 'a' represents an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; 'a' represents an integer from 0 to 5; and multiple 'R's represent alkyl groups with 1 to 3 carbon atoms. 5 They can be the same or different.

[0044] [Chemistry 4]

[0045]

[0046] In equation (5), R 6 R represents a hydrogen atom or a methyl group. 7 The 'b' represents an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; 'b' represents an integer from 0 to 5; and multiple 'R's represent alkyl groups with 1 to 3 carbon atoms. 7 They can be the same or different.

[0047] The weight-average molecular weight (Mw) of component (A) can be 8,000–100,000, 10,000–80,000, 15,000–70,000, or 20,000–50,000. If Mw is below 100,000, there is a tendency to improve resolution and developability; if Mw is above 8,000, there is a tendency to improve the flexibility of the hardened film, reduce the likelihood of resist pattern defects, and prevent peeling. The dispersion (Mw / Mn) of component (A) can be 1.0–3.0, 1.2–2.5, 1.4–2.3, or 1.5–2.0. A smaller dispersion tends to improve resolution. The weight-average molecular weight of the adhesive polymer (A) is determined by gel permeation chromatography (GPC) (converted using a calibration curve of standard polystyrene).

[0048] In the photosensitive resin composition of this embodiment, component (A) may be a single adhesive polymer or may be a combination of two or more adhesive polymers. Examples of adhesive polymers used in combination include two or more adhesive polymers containing different copolymer components (containing different monomer units as copolymer components) and two or more adhesive polymers with different Mw values.

[0049] The acid value of component (A) can be 100 mg KOH / g to 250 mg KOH / g, 120 mg KOH / g to 240 mg KOH / g, 140 mg KOH / g to 230 mg KOH / g, or 150 mg KOH / g to 230 mg KOH / g. With an acid value of 100 mg KOH / g or higher, the increase in development time can be effectively suppressed; with an acid value of 250 mg KOH / g or lower, the resistance (adhesion) of the cured photosensitive resin composition to developer solution can be easily improved.

[0050] (A) The acid value of component A can be determined as follows. First, accurately weigh 1 g of the adhesive polymer to be tested for acid value. Add 30 g of acetone to the accurately weighed adhesive polymer and dissolve it evenly. Then, add an appropriate amount of phenolphthalein as an indicator to the solution and titrate with a 0.1 N aqueous solution of potassium hydroxide (KOH). Calculate the number of mg of KOH required to neutralize the acetone solution of the adhesive polymer to be tested, and then determine the acid value. When a solution composed of the adhesive polymer and synthetic solvents, diluents, etc., is used as the test object, the acid value is calculated using the following formula.

[0051] Acid value = 0.1 × Vf × 56.1 / (Wp × I / 100)

[0052] In the formula, Vf represents the titration volume of KOH aqueous solution (mL), Wp represents the mass (g) of the solution containing the binder polymer, and I represents the proportion (mass%) of the non-volatile components in the solution containing the binder polymer.

[0053] In addition, when the adhesive polymer is mixed with volatile components such as synthetic solvent and diluent solvent, it can be preheated at a temperature 10°C or higher than the boiling point of the volatile components for 1 to 4 hours before accurate weighing, and the acid value can be measured after removing the volatile components.

[0054] Based on the total solid content of the photosensitive resin composition, the content of component (A) in the photosensitive resin composition of this embodiment can be 20% to 90% by mass, 30% to 80% by mass, or 40% to 65% by mass. If the content of component (A) is 20% by mass or more, there is a tendency for excellent film formability; if it is 90% by mass or less, there is a tendency for excellent sensitivity and resolution.

[0055] [Photopolymerizable compound (B)]

[0056] The photopolymerizable compound (B) is not particularly limited as long as it is a compound having at least one of the following vinyl unsaturated bonds and capable of photopolymerization. As component (B), from the viewpoint of improving alkali developability, resolution, and peel properties after curing, it is preferable to include at least one of bisphenol-type (meth)acrylates, more preferably bisphenol A-type (meth)acrylates. Examples of bisphenol A-type (meth)acrylates include: 2,2-bis(4-((meth)acrylate-oxy-polyethoxy)phenyl)propane, 2,2-bis(4-((meth)acrylate-oxy-polypropoxy)phenyl)propane, 2,2-bis(4-((meth)acrylate-oxy-polybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acrylate-oxy-polyethoxy)phenyl)propane. From the viewpoint of further improving resolution and peel properties, 2,2-bis(4-((meth)acrylate-oxy-polyethoxy)phenyl)propane is preferred.

[0057] Commercially available bisphenol A type (meth)acrylates include, for example, 2,2-bis(4-((meth)acrylateoxydipropoxy)phenyl)propane, BPE-200 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name); ethoxylated bisphenol A dimethacrylate, BP-2EM (manufactured by Kyoeisha Chemical Co., Ltd., trade name); and 2,2-bis(4-(methacrylateoxypentethoxy)phenyl)propane, BPE-500 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name) and FA-321M (manufactured by Resonac Co., Ltd., trade name). These bisphenol A type (meth)acrylates can be used alone or in combination of two or more.

[0058] Based on the total amount of component (B), the content of bisphenol (meth)acrylate can be 40%–98% by mass, 50%–97% by mass, 60%–95% by mass, or 70%–95% by mass. If the content is 40% by mass or more, the resolution, adhesion, and inhibition of resist shedding become better; if it is 98% by mass or less, the development time is moderately shortened, and development residue is less likely to occur.

[0059] As component (B) other than bisphenol (meth)acrylates, from the viewpoint of improving the flexibility of the cured material (cured film), it may also include at least one of polyalkylene glycol dimethacrylates having at least one of (poly)oxyethylene chains and (poly)oxypropylene chains within the molecule, and may also include polyalkylene glycol dimethacrylates having both (poly)oxyethylene chains and (poly)oxypropylene chains within the molecule. Examples of such polyalkylene glycol dimethacrylates include FA-023M (manufactured by Resonac Co., Ltd., trade name), FA-024M (manufactured by Resonac Co., Ltd., trade name), and NK ester HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name). These may be used alone or in combination of two or more.

[0060] Based on the total amount of component (B), the content of polyalkylene glycol di(meth)acrylate can be 2% to 40% by mass, 3% to 30% by mass, or 5% to 20% by mass.

[0061] As a component (B) other than those described above, nonylphenoxy polyethylene acrylate, phthalic acid compounds, (meth)acrylate polyol esters, (meth)acrylate alkyl esters, etc., may also be used. From the viewpoint of achieving a good balance in improving resolution, adhesion, resist shape, and peeling properties after curing, component (B) may contain at least one selected from nonylphenoxy polyethylene acrylate and phthalic acid compounds. Since these compounds have relatively low refractive indices, from the viewpoint of improving resolution, their content, based on the total amount of component (B), can be 5% to 50% by mass, 5% to 40% by mass, or 10% to 30% by mass.

[0062] Examples of nonylphenoxy polyethylene oxyacrylates include: nonylphenoxy triethylene oxyacrylate, nonylphenoxy tetraethylene oxyacrylate, nonylphenoxy pentaethylene oxyacrylate, nonylphenoxy hexadecimal oxyacrylate, nonylphenoxy heptaethylene oxyacrylate, nonylphenoxy octaethylene oxyacrylate, nonylphenoxy nonadecimal oxyacrylate, nonylphenoxy decaethylene oxyacrylate, and nonylphenoxy undecaethylene oxyacrylate.

[0063] Examples of phthalic acid compounds include, for instance, γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-o-phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, wherein γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate is commercially available as FA-MECH (manufactured by Resonac, a trade name).

[0064] From the perspective of improving sensitivity and reducing trailing, component (B) may contain (meth)acrylic acid polyols. 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, trimethylolpropane polybutoxytri(meth)acrylate, trimethylolpropane polyeth ... Ethane polyethoxy polypropoxy tri(meth)acrylate, pentaerythritol polyethoxy tri(meth)acrylate, pentaerythritol polypropoxy tri(meth)acrylate, pentaerythritol polybutoxy tri(meth)acrylate, pentaerythritol polyethoxy polypropoxy tri(meth)acrylate, glyceryl polyethoxy tri(meth)acrylate, glyceryl polypropoxy tri(meth)acrylate, glyceryl polybutoxy tri(meth)acrylate, and glyceryl polyethoxy polypropoxy tri(meth)acrylate.

[0065] Relative to the total amount of components (A) and (B) 100 parts by mass, 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. If the content of component (B) is within the aforementioned range, in addition to improved resolution and adhesion of the photosensitive resin composition and better resist shearing, the photosensitivity and coating properties are also improved.

[0066] [Photopolymerization Initiator (C)]

[0067] The photopolymerization initiator (C) comprises a hexaaryl biimidazole compound (C1) having an alkoxy group having three or more carbon atoms in its molecular structure (HABI(C1)). In HABI(C1), the two imidazole rings can be bonded, for example, through a nitrogen atom at position 1 to a carbon atom at position 2. Specifically, the nitrogen atom at position 1 of one imidazole ring can be bonded to a carbon atom at position 2 of the other imidazole ring, or the nitrogen atom at position 1 of one imidazole ring can be bonded to a carbon atom at position 4 or 5 of the other imidazole ring. Furthermore, the positions of the imidazole rings are numbered as follows.

[0068] [Chemistry 5]

[0069]

[0070] The six aryl groups in HABI(C1) are bonded to carbon atoms at positions 2, 4, and 5.

[0071] Regarding the alkoxy groups with 3 or more carbon atoms in HABI(C1), there is no particular limitation as long as the alkoxy group has 3 or more carbon atoms. However, in addition to being a photosensitive resin composition with superior photosensitivity and resolution when forming resist patterns, HABI(C1) also has excellent solvent solubility, and in this respect, a range of 3 to 10 is preferred. Furthermore, in terms of a better balance between the photosensitivity and resolution of the photosensitive resin composition and the solvent solubility of HABI(C1), a range of 3 to 8 is more preferred. The carbon chain of the alkoxy group can be linear or branched. Among these, linear type is preferred in terms of superior solvent solubility of HABI(C1). Specific examples of alkoxy groups include: n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, etc.

[0072] In HABI(C1), alkoxy groups with 3 or more carbon atoms are preferably present as substituents on aryl groups bonded to carbon atoms at the 2, 4, and 5 positions of the imidazole, respectively. The number of alkoxy groups with 3 or more carbon atoms present on one aryl group is not particularly limited, and can be 0 or 1 to 3, or 0, 1, or 2, or 0 or 1. The number of alkoxy groups with 3 or more carbon atoms in HABI(C1) is not particularly limited; for example, it can be 6 or less per molecule, or 3 or less. Preferably, it is in the range of 1 to 3, and particularly preferably 2.

[0073] When a HABI(C1) molecule has two to six alkoxy groups having three or more carbon atoms, these alkoxy groups can be substituted entirely on different aryl groups, or partially or entirely on the same aryl group. From the viewpoint of the stability of the free radical species generated during the reaction, it is preferable that all alkoxy groups are substituted on different aryl groups. When a HABI(C1) molecule has two alkoxy groups having three or more carbon atoms, these are preferably substituents on the aryl group bonded to the imidazole at the 2-position.

[0074] The substitution position of the alkoxy group on each aryl group is not particularly limited, and can be ortho, meta, or para relative to the bonding position with the imidazole ring. However, from the viewpoint of photosensitivity, it is preferable that the alkoxy group is substituted at the ortho position relative to the bonding position with the imidazole ring.

[0075] In HABI(C1), the substituents on the aryl group can include alkoxy groups with 3 or more carbon atoms, or other substituents. Examples of other substituents include hydrocarbon groups with 1 to 6 carbon atoms, methoxy groups, ethoxy groups, etc. The proportion of alkoxy groups with 3 or more carbon atoms relative to the total number of substituents on the aryl group can be 60% or more, 80% or more, 90% or more, or 100%. From the viewpoint of creating a photosensitive resin composition with superior photosensitivity or resolution when forming resist patterns, HABI(C1) can also be a compound having only alkoxy groups with 3 or more carbon atoms as substituents on the aryl group.

[0076] HABI(Cl) may also be a molecular structure that does not contain halogen atoms. In this case, it also depends on what other components are used as other components of the photosensitive resin composition, but it is possible to make the photosensitive resin composition halogen-free or low-halogenated.

[0077] HABI(C1) may also include compounds represented by the following general formula (1).

[0078] [Chemistry 6]

[0079]

[0080] [In general formula (1), X independently represents a hydrogen atom or an alkoxy group of carbon chain 3 to 8, and at least two of the multiple X's are alkoxy groups.]

[0081] Alkoxy groups can be, for example, alkoxy groups with 1 to 10 carbon atoms, or alkoxy groups with 1 to 8 carbon atoms. Specific examples of alkoxy groups with 1 to 8 carbon atoms include: methoxy, ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, etc.

[0082] The compound represented by the general formula (1) may more specifically be the compound represented by the following general formula (1-1).

[0083] [Chemistry 7]

[0084]

[0085] [In general formula (1-1), X is independently an alkoxy group having 3 or more carbon atoms.]

[0086] In general formula (1-1), X is an alkoxy group with 3 or more carbon atoms. X can be an alkoxy group with 3 to 10 carbon atoms, or an alkoxy group with 3 to 8 carbon atoms. Specific examples of alkoxy groups with 3 to 10 carbon atoms include: n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, etc.

[0087] Photopolymerization initiator (C) may also include other photopolymerization initiators besides HABI (C1). When using other photopolymerization initiators, one may be used alone, or two or more may be used in combination. Specific examples of other photopolymerization initiators include: benzophenone compounds, thioxanthone compounds, fluorenone compounds, and acridine compounds as dehydrogenation radical generators; and benzoyl ketal compounds, α-aminophenylalkyl ketone compounds, α-hydroxyphenylalkyl ketone compounds, α-hydroxyacetophenone compounds, and acylphosphine oxide compounds as intramolecular cleavage radical generators.

[0088] The proportion of HABI (Cl) relative to the total mass of the photopolymerization initiator (C) can 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 initiator (C) added to the photosensitive resin composition relative to the total mass of the binder polymer (A) and the photopolymerizable compound (B) can be 0.5% by mass or more, 1% by mass or more, or 3% by mass or more. Alternatively, it can be 15% by mass or less, 10% by mass or less, or 8% by mass or less. The total amount of photopolymerization initiator (C) added relative to the total mass of the binder polymer (A) and the photopolymerizable compound (B) can, for example, range from 0.5% by mass to 15% by mass.

[0089] In addition to the binder polymer (A), photopolymerizable compound (B), and photopolymerization initiator (C), the photosensitive resin composition of one embodiment may also include sensitizing pigment (D), amine compound (E), and other components.

[0090] [Sensitizing Pigment (D)]

[0091] The photosensitive resin composition of this embodiment may contain at least one sensitizing pigment (D). Examples of sensitizing pigments (D) include: dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, xanthonesone compounds, thioxanthonesone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, triazine compounds, thiophene compounds, naphthalenedicarboximide compounds, triarylamine compounds, and aminoacridine compounds. These may be used alone or in combination of two or more.

[0092] Especially when the photosensitive resin composition layer is exposed using photochemical rays of 340 nm to 430 nm, from the viewpoint of sensitivity and adhesion, the sensitizing pigment (D) is preferably at least one sensitizing pigment selected from the group consisting of dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, triarylamine compounds, thioxanone compounds and aminoacridine compounds, more preferably at least one selected from the group consisting of dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds and triarylamine compounds, and even more preferably at least one pyrazoline compound.

[0093] Relative to the total amount of 100 parts by mass of the adhesive polymer (A) and the photopolymerizable compound (B), the content of the sensitizing pigment (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. If the content is 0.01 parts by mass or more, there is a tendency to easily obtain sensitivity and resolution; if it is 10 parts by mass or less, there is a tendency to easily obtain a sufficiently good resist shape.

[0094] The pyrazoline compound is preferably selected from at least one of the group consisting of compounds represented by the following general formula (6) and compounds represented by the following general formula (7).

[0095] [Chemistry 8]

[0096]

[0097] In general formula (6), R 8 ~R 10 Each of the following can independently represent a straight-chain or branched alkyl group with 1 to 12 carbon atoms, or a straight-chain or branched alkoxy group with 1 to 10 carbon atoms, or a halogen atom. Furthermore, c, d, and e can independently represent integers from 0 to 5, and the sum of c, d, and e is 1 to 6. When the sum of c, d, and e is 2 or more, multiple Rs exist. 8 ~R 10 They can be the same or different.

[0098] In general formula (6), R 8 ~R 10 At least one of them is preferably a straight-chain or branched alkyl group having 1 to 12 carbon atoms, or a straight-chain or branched alkoxy group having 1 to 10 carbon atoms, more preferably a straight-chain or branched alkyl group having 1 to 4 carbon atoms, a straight-chain or branched alkoxy group having 1 to 4 carbon atoms, or a phenyl group, and even more preferably tert-butyl, isopropyl, methoxy, or ethoxy.

[0099] As pyrazoline compounds represented by general formula (6), they may be used without particular limitation. Specifically, examples include: 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-dimethoxystyryl)- 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, 1-phenyl-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline and other pyrazoline compounds that correspond to c=0 in the general formula (6).

[0100] [Chemistry 9]

[0101]

[0102] In general formula (7), R 11 ~R 13 Each of these can independently represent a straight-chain or branched alkyl group having 1 to 12 carbon atoms, a straight-chain or branched alkoxy group having 1 to 10 carbon atoms, a halogen atom, or a phenyl group. Furthermore, f, g, and h can independently represent integers from 0 to 5, and the sum of f, g, and h is 1 to 6. When the sum of f, g, and h is 2 or more, multiple R groups exist. 11 ~R 13 They can be the same or different.

[0103] In general formula (7), R 11 ~R 13 At least one of them is preferably a straight-chain or branched alkyl group having 1 to 12 carbon atoms, a straight-chain or branched alkoxy group having 1 to 10 carbon atoms, or a phenyl group, more preferably a straight-chain or branched alkyl group having 1 to 4 carbon atoms, a straight-chain or branched alkoxy group having 1 to 4 carbon atoms, or a phenyl group, and even more preferably tert-butyl, isopropyl, methoxy, ethoxy, or phenyl.

[0104] In addition, pyrazoline compounds represented by general formula (7) can be used without particular limitation, and examples include: 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, and 1-phenyl-3-(4-tert-butylphenyl)-5-(4-methoxyphenyl)-pyrazoline. 1-Phenylacetyl-3-(4-isopropylphenyl)-5-(4-tert-butylphenyl)-pyrazoline, 1-Phenylacetyl-3-(4-tert-butylphenyl)-5-(4-isopropylphenyl)-pyrazoline, 1-Phenylacetyl-3-(4-methoxyphenyl)-5-(4-isopropylphenyl)-pyrazoline, 1-Phenylacetyl-3-(4-isopropylphenyl)-5-(4-methoxyphenyl)-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 -Phenylacetyl-3,5-bis(4-tert-butylphenyl)-pyrazoline, 1,5-diphenyl-3-(4-tert-butylphenyl)-pyrazoline, and other pyrazoline compounds that correspond to d=0 in the general formula (8); 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octylphenyl)-pyrazoline, and other pyrazoline compounds that correspond to d=0 in the general formula (7); 12 =Phenylated pyrazoline compounds.

[0105] As an anthracene compound, it is preferred to include a compound represented by the following general formula (8).

[0106] [Chemistry 10]

[0107]

[0108] In general formula (8), R 14 and R 15 Each of the following can be independently represented: alkyl (1-20 carbon atoms), cycloalkyl (5-12 carbon atoms), phenyl, benzyl, alkanoyl (2-12 carbon atoms), or benzoyl. R 22 ~R 29 Each of the following can be independently represented: hydrogen atom, alkyl group with 1 to 12 carbon atoms, halogen atom, cyano group, carboxyl group, phenyl group, alkoxycarbonyl group with 2 to 6 carbon atoms, or benzoyl group.

[0109] As R in general formula (8) 14 and R 15Examples include: methyl, ethyl, propyl, butyl, pentyl, hexyl, etc. As R... 14 and R 15 Combinations of ethyl groups, for example, combinations of propyl groups, combinations of butyl groups, etc.

[0110] As R 16 ~R 23 Examples of possible combinations include: hydrogen atom, methyl, ethyl, propyl, butyl, pentyl, hexyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, ethoxycarbonyl, hydroxyethoxycarbonyl, and phenoxy. Combinations of R19 to R26 include: all of them being hydrogen atoms; any one of them being methyl, ethyl, propyl, butyl, pentyl, hexyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, ethoxycarbonyl, hydroxyethoxycarbonyl, or phenoxy, with all others being hydrogen atoms; any two of them being combinations independently selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, propenyl, butenyl, pentenyl, heptenyl, ethoxycarbonyl, hydroxyethoxycarbonyl, and phenoxy, with all others being hydrogen atoms.

[0111] R 14 and R 15 Preferably, each is 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 Hydrogen atoms are preferred.

[0112] Examples of compounds represented by general formula (8) include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 9,10-dibutoxyanthracene.

[0113] As a triarylamine compound, at least one of the compounds represented by the following general formula (9) is preferred.

[0114] [Chemistry 11]

[0115]

[0116] In general formula (9), R 24 R 25 and R 26 Each can independently represent an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. i, j, and k represent integers from 0 to 5 chosen such that the value of i+j+k is 1 or higher. Furthermore, when i is 2 or higher, multiple R's exist. 24They can be the same or different. When j is 2 or higher, there are multiple R values. 25 They can be the same or different. When k is 2 or higher, there are multiple R values. 26 They can be the same or different. In general formula (9), R 24 R 25 and R 26 Hydrogen atoms are preferred.

[0117] [Amine compounds (E)]

[0118] 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 leuco crystal violet. These can be used alone or in combination of two or more.

[0119] When the photosensitive resin composition contains an amine compound (E), its content is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B), more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass. If the content is 0.01 parts by mass or more, there is a tendency to easily obtain sufficient sensitivity. If it is 10 parts by mass or less, there is a tendency to suppress the precipitation of excess amine compound as foreign matter in the photosensitive element.

[0120] [Other ingredients]

[0121] The photosensitive resin composition may, as needed, contain photopolymerizable compounds (such as oxobutane compounds) having at least one cyclic ether group capable of cationic polymerization within the molecule, cationic polymerization initiators, dyes such as malachite green, Victoria pure blue, brilliant green, and methyl violet, photochromic agents such as tribromophenyl sulfone, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline, heat-resistant color-developing agents, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoamers, flame retardants, stabilizers, adhesion promoters, leveling agents, peel accelerators, antioxidants, fragrances, developers, and thermal crosslinking agents. These can be used alone or in combination of two or more. When the photosensitive resin composition contains other components, the content of these components is preferably set to about 0.01 parts by weight to 20 parts by weight, respectively, relative to 100 parts by weight of the total amount of the adhesive polymer (A) and the photopolymerizable compound (B).

[0122] [Solution of photosensitive resin composition]

[0123] The photosensitive resin composition may also 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 can be used alone or in combination. The content of organic solvents in the photosensitive resin composition can be appropriately selected according to the purpose, etc. 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 organic solvents will also be referred to as "coating solution").

[0124] [Uses of Photosensitive Resin Compositions]

[0125] The specific application of the photosensitive resin composition in one embodiment is not particularly limited, and it can be used as a dry film-like photosensitive element. The photosensitive element can, for example, be used as a resist patterning material. Alternatively, the photosensitive resin composition can be used directly as a liquid negative resist material.

[0126] [Photosensitive element]

[0127] One embodiment of a photosensitive element includes a support film and a photosensitive resin composition layer disposed on the support film, the photosensitive resin composition layer comprising the photosensitive resin composition previously described. The photosensitive resin composition layer may be a coating of the photosensitive resin composition. Furthermore, the coating of the photosensitive resin composition may be a coating of the photosensitive resin composition in its uncured state. The photosensitive element may also have other layers such as a protective film, as needed.

[0128] An embodiment of a photosensitive element is shown. The photosensitive element can be constructed by sequentially stacking a support film, a photosensitive resin composition layer as a coating film of a photosensitive resin composition, and a protective film. The photosensitive element can be obtained, for example, as follows: A coating layer is formed by coating a support film with a coating liquid comprising a photosensitive resin composition containing an organic solvent, and then dried to form a photosensitive resin composition layer. Subsequently, by covering the side of the photosensitive resin composition layer opposite to the support film with the protective film, a photosensitive element comprising a support film, a photosensitive resin composition layer stacked on the support film, and a protective film stacked on the photosensitive resin composition layer is obtained. The photosensitive element may not necessarily include a protective film.

[0129] As a support membrane, polymer membranes with heat resistance and solvent resistance, such as polyethylene terephthalate, polyester, polypropylene, and polyethylene, can be used.

[0130] 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. By having a support film thickness of 1 μm or more, the possibility of the support film breaking during peeling can be suppressed. Furthermore, by having a thickness of 100 μm or less, the reduction in resolution can be suppressed.

[0131] As a protective film, it is preferable to have a film with lower adhesion to the photosensitive resin composition layer than the support film has to the photosensitive resin composition layer. Furthermore, a low-fisheye film is preferred. Here, "fisheye" refers to the inclusion of foreign matter, undissolved substances, oxidized deteriorated substances, etc., into the film during the manufacturing process of the material using methods such as hot melting, mixing, extrusion, biaxial stretching, and casting. In other words, "low-fisheye" means that the film contains fewer such foreign matter.

[0132] Specifically, as a protective film, polymer films with heat resistance and solvent resistance, such as polyethylene terephthalate (PET), polypropylene, and polyethylene, can be used. Examples of commercially available products include: Alphane MA-410 and E-200 manufactured by Oji Paper Co., Ltd.; polypropylene films manufactured by Shin-Etsu Film Co., Ltd.; and PS series polyethylene terephthalate films such as PS-25 manufactured by Teijin Co., Ltd. Furthermore, the protective film 6 can be the same as the support film 2.

[0133] 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. If the thickness of the protective film is 1 μm or more, the protective film can be prevented from cracking when the photosensitive resin layer and the support film layer are pressed onto the substrate while the protective film is being peeled off. If the thickness is 100 μm or less, the operability and cost-effectiveness are excellent.

[0134] One embodiment of the photosensitive element can be manufactured, for example, as follows. It can be manufactured using a method comprising: preparing a coating liquid comprising an adhesive polymer (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and an organic solvent; applying the coating liquid onto a support film to form a coating layer; and drying the coating layer to form a photosensitive resin composition layer.

[0135] When coating a solution of a photosensitive resin composition onto a support film, it can be done by known methods such as roller coating, comma coating, gravure coating, air knife coating, mold coating, and rod coating.

[0136] Regarding the drying of the coating layer, there are no particular limitations as long as at least a portion of the organic solvent can be removed from the coating layer. It is preferably carried out at 70°C to 150°C for approximately 5 to 30 minutes. From the viewpoint of preventing the diffusion of organic solvent in subsequent processes, the amount of residual organic solvent in the photosensitive resin composition layer after drying is preferably set to 2% by mass or less.

[0137] For ultraviolet light in the wavelength range of 350 nm to 420 nm, the transmittance of the 15 μm layer of the photosensitive resin composition to ultraviolet light is preferably 10% to 100%, more preferably 40% to 90%, and particularly preferably 60% to 80%. If the transmittance is 50% or more, there is a tendency to easily obtain sufficient patterning properties. If it is 90% or less, there is a tendency to easily obtain sufficient resolution. Furthermore, the transmittance can be measured using a UV spectrometer. An example of a UV spectrometer is the Hitachi 228A W-beam spectrophotometer.

[0138] The photosensitive element may also include intermediate layers such as a buffer layer, an adhesive layer, a light-absorbing layer, and a gas barrier layer. For example, the intermediate layer described in Japanese Patent Application Publication No. 2006-098982 may be used as one of these intermediate layers in this embodiment.

[0139] The shape of the photosensitive element is not particularly limited. For example, it can be in sheet form or in a roll wound on a core. When wound in a roll, it is preferable to wind it with the support film on the outside. Examples of core materials include: polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, ABS (acrylonitrile butadiene styrene) resin, and other plastics. Regarding the end face of the thus obtained roll of photosensitive element roller, from the perspective of end face protection, it is preferable to provide an end face partition; from the perspective of preventing edge fusion, it is preferable to provide a moisture-proof end face partition. As a packaging method, it is preferable to wrap it with a black sheet with low moisture permeability.

[0140] One embodiment of the photosensitive element may be suitable as a material for forming resist patterns.

[0141] [Methods for forming resist patterns]

[0142] One embodiment of the method for forming a resist pattern includes: a lamination step, wherein a photosensitive resin composition layer of a photosensitive element is laminated on a substrate; an exposure step, wherein a predetermined portion of the photosensitive resin composition layer is irradiated with photochemical rays to photocur the exposed portion; and a development step, wherein the portion of the photosensitive resin composition layer other than the exposed portion is removed. The method for forming the resist pattern may also include other steps as needed.

[0143] (i) Lamination process

[0144] First, a circuit forming substrate comprising an insulating layer and a conductor layer formed on the insulating layer can be used as the substrate for stacking the photosensitive resin composition layers. Regarding the stacking of the photosensitive resin composition layers on the substrate, for example, when the photosensitive element has a protective film 6, this is performed by pressing the photosensitive resin composition layer of the photosensitive element onto the substrate while heating it after removing the protective film. This yields a laminate consisting of a substrate, a photosensitive resin composition layer, and a support film stacked sequentially.

[0145] From the perspective of adhesion and conformability, the lamination process is preferably performed under reduced pressure. Heating at least one of the photosensitive resin composition layer and the substrate during lamination is preferably performed at a temperature of 70°C to 130°C, and more preferably at approximately 0.1 MPa to 1.0 MPa (1 kgf / cm²). 2 ~10kgf / cm 2 The bonding is performed under pressure of approximately 100°C (approximately 30°C). These conditions are not particularly limited and can be selected as needed. Furthermore, if the photosensitive resin composition layer is heated to 70°C–130°C, preheating of the substrate is unnecessary. Preheating of the substrate can further improve adhesion and conformability.

[0146] (ii) Exposure process

[0147] In the exposure process, at least a portion of the photosensitive resin layer formed on the substrate as described above is irradiated with photochemical rays, thereby photocuring the exposed portion to which the photochemical rays have been irradiated to form a latent image. At this time, if the support film present on the photosensitive resin composition layer is transparent to the photochemical rays, the photochemical rays can be irradiated through the support film. On the other hand, if the support film exhibits light-blocking properties to the photochemical rays, the photosensitive resin composition layer is irradiated with photochemical rays after the support film is removed.

[0148] As an exposure method, one example is the method of irradiating photochemical rays in an image-like manner using a negative or positive mask pattern called the artwork (mask exposure method). Alternatively, methods of irradiating photochemical rays in an image-like manner using laser direct imaging (LDI) or projection exposure methods can also be employed.

[0149] There are no particular restrictions on the source of photochemical rays, and known light sources can be used. For example, gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers, solid-state lasers such as yttrium aluminum garnet (YAG) lasers, semiconductor lasers, and gallium nitride-based blue-violet lasers can be used to effectively emit ultraviolet and visible light.

[0150] From the viewpoint of more reliably obtaining the effects of the present invention, the wavelength of the photochemical ray (exposure wavelength) is preferably set in the range of 340 nm to 430 nm, and more preferably in the range of 350 nm to 420 nm.

[0151] (iii) Developing process

[0152] In the developing process, the portion of the photosensitive resin composition layer other than the exposed portion is removed from the substrate by the developing process, thereby forming a resist pattern on the substrate as a cured product formed by photocuring the photosensitive resin composition layer. If a support film or optical adjustment layer exists on the photosensitive resin composition layer, these are removed, and then the unexposed portion is removed (developed). Both wet and dry developing processes exist in the developing process, but wet developing is widely used.

[0153] In the case of wet development, a developer solution corresponding to the photosensitive resin composition is used, and development is performed using a known development method. Examples of development methods include immersion, coating, spraying, brushing, tapping, scraping, and agitation immersion. From the viewpoint of improving resolution, high-pressure spraying is the most suitable method. Two or more of these methods can also be combined for development.

[0154] The developer can be appropriately selected based on the structure of the photosensitive resin composition. Examples of developers include alkaline aqueous solutions and organic solvent-based developers.

[0155] When alkaline aqueous solutions are used as developing solutions, they are safe, stable, and easy to handle. The bases that can be used as alkaline aqueous solutions include: hydroxides such as lithium, sodium, or potassium hydroxides; 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.

[0156] The alkaline aqueous solution used for developing is preferably a dilute solution of sodium carbonate (0.1% to 5% by mass), potassium carbonate (0.1% to 5% by mass), sodium hydroxide (0.1% to 5% by mass), or sodium tetraborate (0.1% to 5% by mass). The pH of the alkaline aqueous solution is preferably set in the range of 9 to 11. Furthermore, the temperature is adjusted according to the alkaline developability of the photosensitive resin composition layer. Surfactants, defoamers, and small amounts of organic solvents for promoting development may be mixed into the alkaline aqueous solution.

[0157] 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 the range of 1% to 20% by mass to these organic solvents.

[0158] The method for forming the resist pattern may also include the following steps: after removing the unexposed areas, heating at approximately 60°C to 250°C or 0.2 J / cm² as needed. 2 ~10J / cm 2 The exposure to the left and right sides further hardens the resist pattern.

[0159] [Manufacturing method of printed circuit boards]

[0160] The method for manufacturing a printed circuit board disclosed herein includes a step of etching or plating a substrate on which a resist pattern has been formed using the resist pattern forming method to form a conductor pattern. The method may also include other steps, such as a resist removal step, as needed. Using the formed resist pattern as a mask, the conductor layer of the substrate is etched or plated.

[0161] In the etching process, a resist pattern formed on the substrate is used as a mask to etch away the conductor layer of the substrate that is not covered by the resist, thereby forming a conductor pattern. The etching method can be appropriately selected depending on the conductor layer to be removed. Examples of etching solutions include copper chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide etching solution. Among these, ferric chloride solution is preferred in terms of its good etching coefficient.

[0162] On the other hand, in the plating process, a resist pattern formed on the substrate is used as a mask to plate copper and solder onto the conductor layer of the substrate that is not covered by the resist. After the plating process, the resist pattern is removed, and then the conductor layer covered by the resist pattern is etched to form a conductor pattern. The plating process can be electrolytic plating or electroless plating. Examples of plating processes include: copper plating such as copper sulfate plating and copper pyrophosphate plating; solder plating such as high-speed and low-speed solder plating; Watt's bath (nickel sulfate-nickel chloride) plating; nickel plating such as nickel sulfamate; hard gold plating; and soft gold plating.

[0163] After the etching and plating processes, the resist pattern on the substrate is removed (stripped off). For example, a more alkaline aqueous solution than the alkaline aqueous solution used in the developing process can be used to remove the resist pattern. As the strongly alkaline aqueous solution, a 1% to 10% (w / w) sodium hydroxide aqueous solution or a 1% to 10% (w / w) potassium hydroxide aqueous solution can be used. Preferably, a 1% to 10% (w / w) sodium hydroxide aqueous solution or potassium hydroxide aqueous solution is used, more preferably, a 1% to 5% (w / w) sodium hydroxide aqueous solution or potassium hydroxide aqueous solution is used. Examples of methods for stripping the resist pattern include immersion and spraying, which can be used individually or in combination.

[0164] After the resist pattern is removed following the plating process, the resist-coated conductor layer is further etched to form a conductor pattern, thereby manufacturing the desired printed wiring board. The etching method can be appropriately selected depending on the conductor layer to be removed. For example, the aforementioned etching solution can be used.

[0165] The method for manufacturing printed wiring boards disclosed herein is applicable not only to single-layer printed wiring boards, but also to multi-layer printed wiring boards, and also to printed wiring boards with small-diameter through holes.

[0166] Examples of embodiments are listed below. This invention is not limited to these embodiments.

[0167] <1> A photosensitive resin composition comprising an adhesive polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), wherein the photopolymerization initiator (C) comprises a hexaaryl biimidazole compound (C1) having an alkoxy group having three or more carbon atoms in its molecular structure.

[0168] <2> According to the photosensitive resin composition of <1>, wherein the hexaaryl biimidazole compound (C1) has an alkoxy group in the molecular structure having 3 to 8 carbon atoms.

[0169] <3> According to the photosensitive resin composition of <1> or <2>, wherein the hexaaryl biimidazole compound (C1) comprises a compound represented by the following general formula (1).

[0170] [Chemistry 12]

[0171]

[0172] [In general formula (1), X independently represents a hydrogen atom or an alkoxy group of carbon chain 3 to 8, and at least two of the multiple X's are alkoxy groups.]

[0173] <4> The photosensitive resin composition according to any one of <1> to <3> further comprises an amine compound.

[0174] <5> The photosensitive resin composition according to <4>, wherein the amine compound comprises tris(4-dimethylaminophenyl)methane (leuco crystal violet).

[0175] <6> A photosensitive element comprising a support film and a photosensitive resin composition layer formed on the support film comprising any one of the photosensitive resin compositions according to <1> to <5>.

[0176] <7> The photosensitive element according to <6> is a material for forming resist patterns.

[0177] <8> A method for forming a resist pattern, comprising: a lamination step of laminating a photosensitive resin composition layer comprising a photosensitive resin composition according to any one of <1> to <5> on a substrate; an exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with photochemical rays to photocur the exposed portion; and a development step of removing portions of the photosensitive resin composition layer other than the exposed portion from the substrate on which the photosensitive resin composition layer is laminated.

[0178] <9> A method for manufacturing a printed wiring board includes a step of etching or plating a substrate having a resist pattern formed by the resist pattern forming method according to <8> to form a conductor pattern.

[0179] Example

[0180] The present invention will be described in more detail below through embodiments, but the present invention is not limited to the following embodiments.

[0181] Methods for determining weight-average molecular weight (Mw) and number-average molecular weight (Mn)

[0182] Weight-average molecular weight and number-average molecular weight were calculated by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene. The GPC conditions are shown below.

[0183] Detector: L-2490 RI (manufactured by Hitachi, Ltd.)

[0184] Tube Columns: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (manufactured by Resonac Techno Service Co., Ltd.)

[0185] Eluent: Tetrahydrofuran

[0186] Sample concentration: 5 mg / 1 mL

[0187] Injection volume: 200μL

[0188] Flow rate: 2.05 mL / min

[0189] Measurement temperature: 40℃

[0190] Examples 1 to 5 and Comparative Example 1

[0191] [Preparation of photosensitive resin compositions]

[0192] The components were prepared and mixed in the proportions shown in Table 1 below to manufacture a photosensitive resin composition. The amounts of components other than the solvent in Table 1 are values ​​converted from solid components for components that are solutions. The obtained photosensitive resin composition was evaluated according to the following guidelines. The results are shown in Table 2.

[0193] The details of each component in Table 1 are as follows.

[0194] • Adhesive polymer (A-1): A methylpropanediol / toluene solution of a copolymer of methacrylic acid / styrene / 2-hydroxyethyl methacrylate / benzyl methacrylate (mass ratio: 27 / 50 / 3 / 20, weight average molecular weight: 35000).

[0195] • Free radical polymerizable compound (B-1): Polyethylene oxide modified compound of bisphenol A dimethacrylate, with an average total number of ethylene oxide groups in one molecule of 10 (FA-321M manufactured by Resonac Inc.)

[0196] • Free radical polymerizable compound (B-2): ethylene oxide modified compound of bisphenol A dimethacrylate, with an average total number of ethylene oxide groups per molecule of 2.6 (Light Ester BP-2EM manufactured by Kyoei Chemical Co., Ltd.)

[0197] • Free radical polymerizable compound (B-3): Polyalkylene glycol di(meth)acrylate represented by the following general formula (10), with the average sum of l and n being 12 and the average value of m being 6 (FA-024M manufactured by Resonac Co., Ltd.)

[0198] [Chemistry 13]

[0199]

[0200] ·HABI(C1-1): Compounds in which X is an n-propoxy group in the following general formula (1-1)

[0201] ·HABI(C1-2): Compounds in which X is a n-butoxy group in the following general formula (1-1)

[0202] ·HABI(C1-3): Compounds in which X is n-pentyloxy in the following general formula (1-1)

[0203] ·HABI(C1-4): Compounds in which X is n-hexyloxy in the following general formula (1-1)

[0204] ·HABI(C1-5): Compounds in which X is n-octyloxy in the following general formula (1-1)

[0205] ·HABI(C1'-1): Compounds in which X is a chlorine group in the following general formula (1-1)

[0206] [Chemistry 14]

[0207]

[0208] • Sensitive Pigment (D-1): 1-Phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline ("PZ-501D" manufactured by Nippon Chemical Industries, Ltd.)

[0209] • Amine compound (E-1): Leuco crystal violet (tris[4-(dimethylamino)phenyl]methane) (Yamada Chemical Co., Ltd.)

[0210] • Polymerization inhibitor (F-1): Q-TBC-5P manufactured by DIC Corporation, tert-butylcatechol

[0211] • Polymerization inhibitor (F-2): 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxy (LA-7RD manufactured by Adeka Inc.)

[0212] • Adhesion enhancer (G-1): A mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (“Q-SF-808H” manufactured by Sanwa Kasei Corporation)

[0213] • Dye (H-1): Malachite Green (manufactured by Osaka Organic Chemicals Co., Ltd.)

[0214] • Solvent (I-1): Toluene

[0215] • Solvent (I-2): Methanol

[0216] • Solvent (I-3): Acetone

[0217] [Table 1]

[0218]

[0219] [Manufacturing of photosensitive elements]

[0220] The previously obtained photosensitive resin composition was coated onto a support film (*1). It was then dried using 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.

[0221] Support film (*1): 16μm thick polyethylene terephthalate film ("FS-31" manufactured by Toray Industries, Inc.)

[0222] Protective film (*2): 28μm thick polyethylene film (manufactured by Tamapoley Corporation, trade name "NF-15A")

[0223] [Determination of the shortest development time]

[0224] While peeling off the protective film of the photosensitive element, the photosensitive resin composition layer of the photosensitive element is overlapped and laminated in contact with the copper surface of the substrate (*3) to obtain laminate 1 as a laminate. Lamination is performed using a hot roller at 110°C under the conditions of a pressing pressure of 0.4 MPa and a roller speed of 1.0 m / min.

[0225] Substrate (*3): Obtained by sputtering copper onto a polyethylene terephthalate film.

[0226] Next, the support film was peeled off and used as a test piece. The unexposed photosensitive resin composition layer in the test piece was spray-developed using a 1.0% by mass sodium carbonate aqueous solution at 30°C and a pressure of 0.10 MPa. The shortest development time was defined as the shortest time in which the unexposed photosensitive resin composition layer was completely removed, which could be visually confirmed.

[0227] [Exposure Measurement]

[0228] After placing a 41-step platen (manufactured by Resonac Co., Ltd.) on the support film of laminate 1, exposure was performed using a projection exposure apparatus (manufactured by Ushio Electric Co., Ltd., trade name "UX-2240") with an ultra-high pressure mercury lamp (365nm) as the light source. After peeling off the support film, development was performed using a 1.0% by mass sodium carbonate aqueous solution at 30°C, with a spray pressure of 0.10 MPa and a development time twice the minimum development time. By varying the exposure amount, a calibration curve regarding the number of residual steps was created, and the exposure amount for the 41-step platen after development was calculated to be 11 steps.

[0229] [Evaluation of proximity and resolution]

[0230] After placing glass-chrome type photographic tools 1 and 2 (*) on the support film of the laminate 1, exposure was performed using a projection exposure device (manufactured by Ushio Electric Co., Ltd., trade name "UX-2240") with an ultra-high pressure mercury lamp (365nm) as the light source, with an exposure dose of 11 levels of residual steps after development of the previously measured 41-step plate. The focusing position was set to the upper part of the film thickness of the photosensitive resin composition layer.

[0231] After peeling off the support film, development was performed using a 1.0% by mass sodium carbonate aqueous solution at 30°C, with a spray pressure of 0.10 MPa and a development time twice the shortest possible time. Using various photographic tools, the minimum x value for obtaining a clear resist pattern where the unexposed areas (spaces) are completely removed and the exposed areas (wireless areas) are not tilted, meandering, or lacking in definition was taken as the adhesion and resolution. The test was performed three times, and the average x value was used for evaluation.

[0232] • Photo Tool 1: Line width / space width = x / 3x (closeness), where x is 1μm to 10μm

[0233] • Photo Tool 2: Line width / Spatial width = 3x / x (resolution), where x is 1μm to 10μm

[0234] [Table 2]

[0235] As shown in Table 2, the photosensitive resin compositions of Examples 1 to 5 have higher photosensitivity than the photosensitive resin composition of Comparative Example 1, so that high-resolution resist patterns can be formed even with low exposure.

Claims

1. A photosensitive resin composition comprising an adhesive 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 having three or more carbon atoms in its molecular structure.

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

3. The photosensitive resin composition according to claim 1, wherein the hexaaryl biimidazole compound (C1) comprises a compound represented by the following general formula (1), [Chemistry 1] [In general formula (1), X independently represents a hydrogen atom or an alkoxy group of carbon chain 3 to 8, and at least two of the multiple X's are alkoxy groups].

4. The photosensitive resin composition according to claim 1 further comprises an amine compound.

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

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

7. The photosensitive element according to claim 6, wherein it is a material for resist patterning.

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

9. A method for manufacturing a printed wiring board, comprising a step of etching or plating a substrate having a resist pattern formed by the resist pattern forming method as described in claim 8 to form a conductor pattern.

Images