Photosensitive element, method for forming resist pattern, and method for manufacturing printed wiring board

Abstract

Provided is a photosensitive element comprising a support film and a photosensitive resin composition layer, wherein: the thickness of the photosensitive resin composition layer is 10 μm or less; the photosensitive resin composition layer contains a photosensitive resin composition containing a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C); and the photopolymerization initiator (C) contains a hexaarylbiimidazole compound (C1) having an alkoxy group having 3 or more carbon atoms in the molecular structure.

Description

Photosensitive element, method for forming a resist pattern, and method for manufacturing a printed circuit board.

[0001] This disclosure relates to 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 compositions are widely used as resist materials in conductor pattern formation processes such as etching and plating. As one type of resist pattern formation material, a laminated film type photosensitive element is available on the market, in which a photosensitive resin composition layer, which is a dried coating of the photosensitive resin composition, is formed on a support film, and a protective film is placed on top of that.

[0003] Recently, circuit patterns have become increasingly miniaturized, and there is a need for the development of photosensitive resin compositions that can accommodate this. Basic and important performance requirements for photosensitive resin compositions include sufficient photosensitivity even with low exposure and the ability to form high-resolution patterns. Furthermore, there is a growing demand for reduced environmental impact and improved safety in the workplace for industrial chemical products. As one such demand, there is a need for the development of products that contain minimal or reduced levels of halogen atoms, toluene, and other similar substances.

[0004] Photosensitive resin compositions mainly consist of a binder polymer, a photopolymerizable compound, and a photopolymerization initiator, and hexaarylbiimidazole compounds (hereinafter sometimes referred to as "HABI") are known as photopolymerization initiators (see Patent Document 1).

[0005] Japanese Patent Publication No. 2011-237736

[0006] As mentioned above, HABI is one of the photopolymerization initiators used in photosensitive resin compositions, but known HABIs such as those described in Patent Document 1 did not meet the performance levels required in terms of light sensitivity and resolution.

[0007] One of the objectives of this disclosure is to provide a photosensitive element with excellent light sensitivity and resolution, 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 element comprising a support film and a photosensitive resin composition layer, wherein the thickness of the photosensitive resin composition layer is 10 μm or less, and the photosensitive resin composition layer comprises 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.

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

[0010] This is a schematic cross-sectional view showing one embodiment of the photosensitive element of the present disclosure.

[0011] The embodiments of this disclosure are described in detail below. This disclosure is not limited to the embodiments described below.

[0012] In this disclosure, the term "process" includes not only processes that can be clearly distinguished as independent processes, but also processes that, even if their boundaries with other processes are not clear and they cannot be distinguished as independent processes, include the intended operation of that process or achieve the intended effect of that process.

[0013] In this disclosure, the term "layer" includes not only the structural shape formed on the entire surface when observed as a plane, but also the structural shape formed on a part of the surface.

[0014] 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.

[0015] Unless otherwise specified, the photosensitive resin compositions of this disclosure may contain one or more substances corresponding to each component. In cases where a photosensitive resin composition contains multiple substances corresponding to a certain component, unless otherwise specified, the content of such component in the photosensitive resin composition means the total amount of such multiple substances present in the photosensitive resin composition.

[0016] 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.

[0017] 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.

[0018] 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

[0019] A photosensitive element according to one embodiment of the present disclosure is a photosensitive element comprising a support film and a photosensitive resin composition layer, wherein the thickness of the photosensitive resin composition layer is 10 μm or less, and the photosensitive resin composition layer comprises 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.

[0020] In one embodiment, the photosensitive element has superior photosensitivity and resolution compared to conventional photosensitive elements using HABI that does not have alkoxy groups with three or more carbon atoms in its molecular structure, because the photosensitive resin composition layer contains a hexaarylbiimidazole compound (C1) having an alkoxy group with three or more carbon atoms in its molecular structure as a photopolymerization initiator (C) (hereinafter sometimes referred to as "HABI(C1)"). The reason for this is not limited to any particular theory, but it is possible that HABI(C1) has a higher absorbance of light at the wavelength used for exposure compared to conventional HABI, or that the solubility of HABI(C1) in components other than HABI(C1) in the photosensitive resin composition is improved because HABI(C1) has an alkoxy group with three or more carbon atoms, resulting in a more efficient radical chain reaction and enabling the formation of fine patterns with high resolution.

[0021] [Binder Polymer (A)] The photosensitive resin composition contains at least one binder polymer (A). Binder polymer (A) can be obtained, for example, by radical polymerization of a polymerizable monomer.

[0022] Polymerizable monomers include (meth)acrylic acid; alkyl (meth)acrylate esters, cycloalkyl (meth)acrylate esters, benzyl (meth)acrylate, benzyl (meth)acrylate derivatives, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, α-bromoacrylic acid, α-chloroacrylic acid, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, isobornyloxyethyl (meth)acrylate, cyclohexyloxyethyl (meth)acrylate, adamantyl (meth)acrylate Examples include (meth)acrylic acid esters such as ethyl oxyethyl, dicyclopentenyloxypropyl oxyethyl (meth)acrylate, dicyclopentanyloxypropyl oxyethyl (meth)acrylate, dicyclopentenyloxypropyl oxyethyl (meth)acrylate, adamantyloxypropyl oxyethyl (meth)acrylate, β-furyl(meth)acrylic acid, and β-styryl(meth)acrylic acid; styrene; polymerizable styrene derivatives substituted at the α-position or aromatic ring, such as vinyltoluene and α-methylstyrene; acrylamides such as diacetone acrylamide; acrylonitrile; ether compounds of vinyl alcohols such as vinyl-n-butyl ether; maleic acid; maleic anhydride; maleic acid monoesters such as monomethyl maleic acid, monoethyl maleic acid, and monoisopropyl maleic acid; and unsaturated carboxylic acid derivatives such as fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. These can be used individually or in any combination of two or more types.

[0023] From the viewpoint of improving resolution and adhesion, the binder polymer (A) preferably has constituent units derived from at least one polymerizable monomer selected from the group consisting of benzyl (meth)acrylate, benzyl (meth)acrylate derivatives, styrene, and styrene derivatives. It is even more preferable that it contains both at least one selected from the group consisting of benzyl (meth)acrylate and benzyl (meth)acrylate derivatives, and at least one selected from the group consisting of styrene and styrene derivatives. In other words, the binder polymer (A) is preferably obtained by radical polymerization of these polymerizable monomers, and it is preferable that it has constituent units derived from these polymerizable monomers.

[0024] When the binder polymer (A) has constituent units derived from benzyl (meth)acrylate or its derivatives, the content thereof is preferably 3% to 85% by mass, more preferably 5% to 75% by mass, even more preferably 10% to 70% by mass, and particularly preferably 10% to 50% by mass, based on the total mass of polymerizable monomers constituting the binder polymer (A) component (100% by mass, the same applies hereinafter), in terms of excellent resolution and peelability. In terms of excellent resolution, the content is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. Furthermore, in terms of excellent peelability and adhesion, the content is preferably 85% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, and particularly preferably 50% by mass or less.

[0025] When the binder polymer (A) has constituent units derived from styrene or its derivatives, the content thereof is preferably 10% to 70% by mass, more preferably 15% to 60% by mass, and even more preferably 20% to 55% by mass, based on the total mass of polymerizable monomers constituting the binder polymer (A), in terms of excellent adhesion and peelability. In terms of excellent adhesion, the content is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. Furthermore, in terms of excellent peelability, the content is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less.

[0026] Furthermore, from the viewpoint of improving alkali developability and peelability, the binder polymer (A) preferably has constituent units derived from alkyl (meth)acrylate.

[0027] As the alkyl (meth)acrylate ester, alkyl (meth)acrylate esters having an alkyl group with 1 to 12 carbon atoms are preferred. Examples of alkyl (meth)acrylate esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. These can be used individually or in any combination of two or more.

[0028] When the binder polymer (A) has constituent units derived from (meth)acrylate alkyl ester, the content thereof is preferably 1% to 30% by mass, more preferably 2% to 20% by mass, and even more preferably 3% to 10% by mass, based on the total mass of polymerizable monomers constituting the binder polymer (A), in terms of excellent peelability, resolution, and adhesion. In terms of excellent peelability, the content is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. Furthermore, in terms of excellent resolution and adhesion, the content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0029] From the viewpoint of improving the flexibility and adhesion of the formed resist pattern, the binder polymer (A) preferably has structural units derived from at least one (meth)acrylate selected from the group consisting of (EO)-modified dicyclopentenyl (meth)acrylate, (EO)-modified dicyclopentanyl (meth)acrylate, (EO)-modified isobornyl (meth)acrylate, (EO)-modified adamantyl (meth)acrylate, and (EO)-modified cyclohexyl (meth)acrylate (hereinafter also referred to as "(EO)-modified alicyclic (meth)acrylate"). Among these, it is preferable to contain one or more selected from the group consisting of (EO)-modified dicyclopentenyl (meth)acrylate and (EO)-modified dicyclopentanyl (meth)acrylate, and it is more preferable to contain (EO)-modified dicyclopentenyl (meth)acrylate.

[0030] When the binder polymer (A) has constituent units derived from (EO)-modified alicyclic (meth)acrylate, the content thereof is preferably 3% to 85% by mass, more preferably 4% to 70% by mass, and even more preferably 5% to 50% by mass, based on the total mass of polymerizable monomers constituting the binder polymer (A). From the viewpoint of superior adhesion, flexibility, and pliability, this content is preferably 3% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more. Furthermore, from the viewpoint of superior resolution, this content is preferably 85% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less.

[0031] The acid value of the binder polymer (A) is preferably 90 mg KOH / g to 250 mg KOH / g, more preferably 100 mg KOH / g to 240 mg KOH / g, even more preferably 120 mg KOH / g to 235 mg KOH / g, and particularly preferably 130 mg KOH / g to 230 mg KOH / g, in terms of excellent developability and adhesion. In terms of shortening the development time, this acid value is preferably 90 mg KOH / g or more, more preferably 100 mg KOH / g or more, even more preferably 120 mg KOH / g or more, and particularly preferably 130 mg KOH / g or more. Furthermore, in terms of obtaining sufficient adhesion of the cured product of the photosensitive resin composition, this acid value is preferably 250 mg KOH / g or less, more preferably 240 mg KOH / g or less, even more preferably 235 mg KOH / g or less, and particularly preferably 230 mg KOH / g or less. Furthermore, when performing solvent development, it is preferable to prepare a small amount of polymerizable monomers having a carboxyl group, such as (meth)acrylic acid.

[0032] The weight-average molecular weight (Mw) of the binder polymer (A) is preferably 10,000 to 200,000, more preferably 20,000 to 100,000, even more preferably 25,000 to 80,000, and particularly preferably 30,000 to 60,000, in terms of excellent developability and adhesion. In terms of excellent developability, it is preferably 200,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and particularly preferably 60,000 or less. In terms of excellent adhesion, it is preferably 10,000 or more, more preferably 20,000 or more, even more preferably 25,000 or more, and particularly preferably 30,000 or more.

[0033] The degree of dispersion (weight-average molecular weight / number-average molecular weight) of the binder polymer (A) is preferably 3.0 or less, more preferably 2.8 or less, and even more preferably 2.5 or less, in terms of excellent resolution and adhesion.

[0034] Furthermore, the binder polymer (A) may optionally have a characteristic group within its molecule that is photosensitive to light having a wavelength in the range of 340 nm to 430 nm. Examples of such characteristic groups include groups formed by removing at least one hydrogen atom from a sensitizing dye, which will be described later.

[0035] The binder polymer (A) may be used alone or in any combination of two or more types.

[0036] In the photosensitive resin composition, the content of the binder polymer (A) is preferably 30 to 70 parts by mass, more preferably 35 to 65 parts by mass, and particularly preferably 40 to 60 parts by mass, per 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B), in terms of excellent film-forming properties, sensitivity, and resolution. From the viewpoint of film (photosensitive resin composition layer) formation, the content is preferably 30 parts by mass or more, more preferably 35 parts by mass or more, and particularly preferably 40 parts by mass or more. Furthermore, from the viewpoint of obtaining sufficient sensitivity and resolution, the content is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 60 parts by mass or less.

[0037] [Photopolymerizable compound (B)] Photopolymerizable compound (B) may include at least one mono(meth)acrylate compound having a structure selected from a phenyl group, a benzyl group, a dicyclopentanyl group, a dicyclopentenyl group, or a biphenyl group. More specifically, it may include a compound represented by the following general formula (1).

[0038]

[0039] [In general formula (1), R １ R represents a hydrogen atom or a methyl group. ２ R represents an alkylene group with 1 to 4 carbon atoms. ３ [where represents an organic group with 6 to 14 carbon atoms that includes a cyclic structure. where a represents 0 to 2.]

[0040] The compound represented by the above general formula (1) has an organic group R ３ Due to the bulky cyclic structure contained within, it maintains low swelling through physical interactions after photocuring while exhibiting excellent peelability. Furthermore, -(R ２ O) The flexible substructure of a- can further improve flexibility.

[0041] In the above general formula (1), R ３ This represents an organic group with 6 to 14 carbon atoms that includes a cyclic structure. ３The organic group represented by may have at least one cyclic group, and in addition to the cyclic group, it may also have a linear or branched alkyl group. Examples of the cyclic group include saturated or unsaturated aliphatic hydrocarbon ring groups, aromatic hydrocarbon ring groups, saturated or unsaturated aliphatic heterocyclic groups, aromatic heterocyclic groups, etc. The cyclic group may be any of a monocyclic ring, a condensed ring, a bridged ring, a spiro ring, a ring assembly in which a plurality of rings are connected by covalent bonds, etc.

[0042] The cyclic group is preferably a saturated aliphatic hydrocarbon ring group of a monocyclic ring, a condensed ring or a bridged ring, an unsaturated aliphatic hydrocarbon ring group of a monocyclic ring, a condensed ring or a bridged ring, or an aromatic hydrocarbon group of a monocyclic ring, a condensed ring or a ring assembly. From the viewpoint of further improving the resolution, R ３ is more preferably a phenyl group, a benzyl group, a dicyclopentanyl group, a dicyclopentenyl group, or a biphenyl group, and even more preferably a phenyl group, a dicyclopentanyl group, or a dicyclopentenyl group.

[0043] In the general formula (1), R ２ represents an alkylene group having 1 to 4 carbon atoms. R ２ is preferably an ethylene group or a propylene group, and more preferably an ethylene group. The propylene group may be either an n-propylene group or an isopropyl group.

[0044] In the general formula (1), a represents 0 to 2. Here, a indicates the degree to which an alkyleneoxy group having 1 to 4 carbon atoms is added in the molecule. Therefore, for a single molecule, it represents an integer value, but for an aggregate of a plurality of types of molecules, it represents a rational number that is an average value.

[0045] The compound represented by the general formula (1) preferably has a boiling point of 150 ° C or higher at normal pressure, more preferably 180 ° C or higher, and even more preferably 200 ° C or higher. When the boiling point is 150 ° C or higher at normal pressure, it serves as a criterion for suppressing the volatilization of the compound represented by the general formula (1) in the drying step when manufacturing a photosensitive element using the photosensitive resin composition.

[0046] The compound represented by general formula (1) preferably has a molecular weight of 100 to 500, more preferably 120 to 400, and even more preferably 130 to 360, in order to further improve resolution.

[0047] The compound represented by the above general formula (1) may be a commercially available product or one synthesized by conventional methods. The compound represented by general formula (1) can be obtained, for example, by reacting (meth)acrylic acid with (poly)alkylene glycol and an organic compound containing a cyclic structure with 6 to 14 carbon atoms and a leaving group such as a hydroxyl group or a halogen atom.

[0048] Industrial methods for producing (meth)acrylate compounds include transesterification and dehydration esterification. An example of synthesis by transesterification is shown below. An alkylene oxide is added to an alcohol containing a cyclic structure with 6 to 14 carbon atoms. A transesterification reaction between the resulting alkylene oxide-added alcohol derivative and a (meth)acrylic acid ester yields a (meth)acrylic acid ester compound having an organic group with 6 to 14 carbon atoms containing a cyclic structure and a (poly)alkylene oxy group.

[0049] As for commercially available products of the compound represented by general formula (1), R ３ As a compound exhibiting a dicyclopentenyl group, dicyclopentenyloxyethyl methacrylate (FA-512MT, manufactured by Resonaq Corporation), R ３ As a compound exhibiting a dicyclopentanyl group, dicyclopentanyl methacrylate (FA-513M, manufactured by Resonaq Corporation), R ３ As a compound exhibiting a benzyl group, benzyl methacrylate (FA-BZM, manufactured by Resonaq Corporation), R ３ As a compound exhibiting a phenyl group, phenoxyethyl methacrylate (FA-310M, manufactured by Resonaq Corporation), R ３ Examples of compounds exhibiting a biphenyl group include biphenyloxyethyl methacrylate.

[0050] The compound represented by the above general formula (1) is R ３is a phenyl group, a benzyl group, a dicyclopentanyl group, a dicyclopentenyl group, or a biphenyl group, R ２ It is preferable that is at least one compound in which is an ethylene group or a propylene group and a is 0 or 1, and more preferably at least one selected from the group consisting of dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, and biphenyloxyethoxyethyl methacrylate.

[0051] The photosensitive resin composition may include a photopolymerizable compound (B) other than the compound represented by general formula (1). There are no particular restrictions on the photopolymerizable compound other than the compound represented by general formula (1), as long as it is capable of photopolymerization. The photopolymerizable compound other than the compound represented by general formula (1) is preferably a compound having an ethylenically unsaturated bond. Examples of compounds having an ethylenically unsaturated bond include compounds having one ethylenically unsaturated bond in the molecule, compounds having two ethylenically unsaturated bonds in the molecule, compounds having three or more ethylenically unsaturated bonds in the molecule, and so on.

[0052] The photopolymerizable compound (B) preferably contains at least one compound having two ethylenically unsaturated bonds in its molecule. When the photopolymerizable compound (B) contains a compound having two ethylenically unsaturated bonds in its molecule, its content is preferably 5 to 60 parts by mass, more preferably 5 to 55 parts by mass, and even more preferably 10 to 50 parts by mass, per 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B).

[0053] Examples of compounds having two ethylenically unsaturated bonds in their molecule include bisphenol A-based di(meth)acrylate compounds, hydrogenated bisphenol A-based di(meth)acrylate compounds, di(meth)acrylate compounds having a urethane bond in their molecule, and polyalkylene glycol di(meth)acrylate and trimethylolpropane di(meth)acrylate having both a (poly)oxyethylene group and a (poly)oxypropylene group in their molecule.

[0054] From the viewpoint of improving resolution and peeling properties, the photopolymerizable compound (B) preferably contains at least one compound having two ethylenically unsaturated bonds in its molecule, selected from the group consisting of bisphenol A-based di(meth)acrylate compounds, hydrogenated bisphenol A-based di(meth)acrylate compounds, and polyalkylene glycol di(meth)acrylates having a (poly)oxyethylene group and a (poly)oxypropylene group in their molecule.

[0055] Examples of bisphenol A-based di(meth)acrylate compounds include those represented by the following general formula (2).

[0056]

[0057] [In general formula (2), R ６ Each of these independently represents either a hydrogen atom or a methyl group. ４ O and R ５ Each O independently represents either an oxyethylene group or an oxypropylene group. (R ４ O) b1, (R ４ O) b2, (R ５ O) c1, (R ５ O) c2 represents a (poly)oxyethylene group or a (poly)oxypropylene group. b1, b2, c1, and c2 each independently represent values ​​from 0 to 40. R ４ O is an oxyethylene group, R ５ When O is an oxypropylene group, b1 + b2 is 1 to 40, and c1 + c2 is 0 to 20. ４ O is an oxypropylene group, R ５ When O is an oxyethylene group, b1 + b2 is between 0 and 20, and c1 + c2 is between 1 and 40. b1, b2, c1, and c2 represent the number of constituent units of the constituent unit. Therefore, a single molecule will show an integer value, while a collection of multiple molecules will show a rational number, which is the average value. The same applies to the number of constituent units of the constituent unit below.

[0058] In terms of superior resolution, it is preferable to use in combination a compound in which b1 + b2 is in the range of 8 to 40 and a compound in which b1 + b2 is in the range of 1 to 7 in the above general formula (2). Furthermore, R ４O is an oxyethylene group, R ５ A compound in which O is an oxypropylene group, b1 + b2 is in the range of 8 to 40, and c1 and c2 are 0, and R ４ O is an oxyethylene group, R ５ It is preferable to use in combination with a compound in which is an oxypropylene group, b1 + b2 is in the range of 1 to 7, and c1 and c2 are 0. ４ O is an oxyethylene group, R ５ The proportion of compounds in which O is an oxypropylene group, b1 + b2 is in the range of 8 to 40, and c1 and c2 are 0 may be 60% by mass or more, 70% by mass or more, or 80% by mass or more. It may also be 95% by mass or less, or 90% by mass or less. R in relation to the sum of both ４ O is an oxyethylene group, R ５ The proportion of compounds in which O is an oxypropylene group, b1 + b2 is in the range of 8 to 40, and c1 and c2 are 0 may be in the range of 60 to 95% by mass.

[0059] Of the compounds represented by the above general formula (2), 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane is commercially available as BPE-500 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name) or FA-321M (manufactured by Resonac Co., Ltd., product name), and 2,2-bis(4-(methacryloxypentadecaethoxy)phenyl)propane is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name). Also, R ４ O is an oxyethylene group, R ５ Compounds in which O is an oxypropylene group, c1 and c2 are 0, and the average total number of oxyethylene groups in one molecule is 2.6 are commercially available as Light Ester BP-2EM (manufactured by Kyoeisha Chemical Co., Ltd., product name). These can be used alone or in any combination of two or more types.

[0060] When the photosensitive resin composition contains a bisphenol A-based di(meth)acrylate compound as the photopolymerizable compound (B), the content is preferably 1 to 50 parts by mass, and more preferably 5 to 50 parts by mass, per 100 parts by mass of the total amount of the binder polymer (A) and the photopolymerizable compound (B).

[0061] Examples of hydrogenated bisphenol A-type di(meth)acrylate compounds include 2,2-bis(4-(methacryloxypentaethoxy)cyclohexyl)propane.

[0062] From the viewpoint of improving the flexibility of the cured product (cured film) of the photosensitive resin composition, it is preferable that the photopolymerizable compound (B) includes at least one type of polyalkylene glycol di(meth)acrylate. When the above photosensitive resin composition includes polyalkylene glycol di(meth)acrylate as the photopolymerizable compound (B), its content is preferably 0.5 to 20 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the total amount of binder polymer (A) and photopolymerizable compound (B).

[0063] As the polyalkylene glycol di(meth)acrylate compound, polyalkylene glycol di(meth)acrylate having both a (poly)oxyethylene group and a (poly)oxypropylene group in the molecule is preferred. Within the molecule of the polyalkylene glycol di(meth)acrylate, the (poly)oxyethylene group and the (poly)oxypropylene group may be present in a continuous, block-like manner or randomly. The oxypropylene group in the (poly)oxypropylene group may be either an oxy-n-propylene group or an oxyisopropylene group. Furthermore, in the (poly)oxyisopropylene group, the secondary carbon of the propylene group may be bonded to the oxygen atom, or the primary carbon may be bonded to the oxygen atom.

[0064] Polyalkylene glycol di(meth)acrylate may have (poly)oxy-n-butylene groups, (poly)oxyisobutylene groups, (poly)oxy-n-pentylene groups, (poly)oxyhexylene groups, or (poly)oxyalkylene groups having about 4 to 6 carbon atoms, such as structural isomers thereof.

[0065] As the polyalkylene glycol di(meth)acrylate, compounds represented by any of the following general formulas (3), (4), and (5) are preferred. These can be used individually or in combination of two or more.

[0066]

[0067] [In general formulas (3), (4), and (5), R ７ ~R ９ Each of these independently represents a hydrogen atom or a methyl group. EO represents an oxyethylene group, and PO represents an oxypropylene group. d1, d2, d3, and d4 represent the number of constituent units of the oxyethylene group, and e1, e2, e3, and e4 represent the number of constituent units of the oxypropylene group. The number of constituent units of the oxyethylene group d1 + d2, d3, and d4 each independently represents 1 to 30, and the number of constituent units of the oxypropylene group e1, e2 + e3, and e4 each independently represents 1 to 30. Note that these values ​​may be average values.

[0068] In the compounds represented by general formulas (3), (4), and (5), the number of constituent units d1+d2, d3, and d4 of the oxyethylene group is 1 to 30, preferably 1 to 24, more preferably 4 to 20, and particularly preferably 5 to 16. When the total number of these constituent units is 30 or less, it tends to be easier to obtain sufficient resolution, adhesion, and resist shape.

[0069] Furthermore, the number of constituent units e1, e2 + e3, and e4 of the oxypropylene group is 1 to 30, preferably 2 to 20, more preferably 3 to 16, and particularly preferably 4 to 14. When the total number of these constituent units is 30 or less, it tends to be easier to obtain sufficient resolution and to suppress the generation of sludge.

[0070] Compounds represented by general formula (3) include two R ７ Examples include vinyl compounds (manufactured by Resonaq Corporation, product name "FA-023M") in which the group is a methyl group, d1 + d2 = 6 (average value), and e1 = 12 (average value). Compounds represented by general formula (4) include those with two R groups. ８ Examples include vinyl compounds (manufactured by Resonaq Corporation, product name "FA-024M") in which the group is a methyl group, d3 = 12 (average value), and e2 + e3 = 6 (average value). Compounds represented by general formula (5) include those with two R ９ Examples include vinyl compounds (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., sample name "NK Ester HEMA-9P") in which the ions are hydrogen atoms, d4 = 1 (average value), and e4 = 9 (average value). These can be used individually or in combination of two or more types.

[0071] From the viewpoint of balancing resolution and flexibility, the photopolymerizable compound (B) preferably contains two or more compounds having two ethylenically unsaturated bonds in the molecule, more preferably two or more compounds having two ethylenically unsaturated bonds in the molecule selected from the group consisting of bisphenol A-based di(meth)acrylate compounds, hydrogenated bisphenol A-based di(meth)acrylate compounds, and polyalkylene glycol di(meth)acrylates having a (poly)oxyethylene group and a (poly)oxypropylene group in the molecule, and even more preferably two or more compounds having two ethylenically unsaturated bonds in the molecule selected from the group consisting of bisphenol A-based di(meth)acrylate compounds.

[0072] The photopolymerizable compound (B) may contain at least one photopolymerizable compound having three or more ethylenically unsaturated bonds in its molecule.

[0073] Examples of compounds having three or more ethylenically unsaturated bonds include trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate (with 1 to 5 oxyethylene groups), PO-modified trimethylolpropane tri(meth)acrylate, EO / PO-modified trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, or dipentaerythritol hexa(meth)acrylate. These can be used individually or in combination of two or more types.

[0074] Tetramethylolmethane triacrylate is commercially available as A-TMM-3 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name), EO-modified trimethylolpropane trimethacrylate as TMPT21E and TMPT30E (manufactured by Resonaq Co., Ltd., sample name), pentaerythritol triacrylate as SR444 (manufactured by Sartomer Co., Ltd., product name), dipentaerythritol hexaacrylate as A-DPH (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name), and ethoxylated pentaerythritol tetraacrylate as ATM-35E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name).

[0075] The photopolymerizable compound (B) may include a photopolymerizable compound other than the compound represented by general formula (1) that has one ethylenically unsaturated bond in its molecule, from the viewpoint of improving resolution, adhesion, resist shape, suppression of scum generation, or peelability after curing in a balanced manner.

[0076] Examples of photopolymerizable compounds having one ethylenically unsaturated bond in the molecule other than the compound represented by general formula (1) include nonylphenoxypolyethylene oxyacrylate, phthalate compounds, and alkyl (meth)acrylates. Among these, it is preferable to include nonylphenoxypolyethylene oxyacrylate or phthalate compounds from the viewpoint of improving resolution, adhesion, resist shape, and peelability after curing in a balanced manner.

[0077] The photopolymerizable compound (B) preferably contains at least one compound having two ethylenically unsaturated bonds in its molecule, more preferably contains at least two compounds having two ethylenically unsaturated bonds in its molecule, is even more preferably contains two or more compounds having two ethylenically unsaturated bonds in its molecule, selected from the group consisting of bisphenol A-based di(meth)acrylate compounds, hydrogenated bisphenol A-based di(meth)acrylate compounds, and polyalkylene glycol di(meth)acrylates having a (poly)oxyethylene group and a (poly)oxypropylene group in their molecule, and is particularly preferably contains two or more compounds having two ethylenically unsaturated bonds in their molecule, selected from the group consisting of bisphenol A-based di(meth)acrylate compounds.

[0078] The total content of the photopolymerizable compound (B) in the photosensitive resin composition is preferably 30 to 70 parts by mass, more preferably 35 to 65 parts by mass, and particularly preferably 35 to 50 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 30 parts by mass or more, sufficient sensitivity and resolution tend to be easily obtained. When the content is 70 parts by mass or less, it tends to be easier to form a film (photosensitive resin composition layer) and also tends to be easier to obtain a good resist shape.

[0079] [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.

[0080]

[0081] The six aryl groups in HABI(C1) are bonded to the carbon atoms at positions 2, 4, and 5 of the imidazole.

[0082] 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 element with even better photosensitivity and resolution, and also improves the solvent solubility of HABI(C1). Furthermore, it is even 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 element 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 results in even better 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, etc.

[0083] 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.

[0084] 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 solvent solubility, it is preferable that HABI(C1) is substituted on all 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.

[0085] 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.

[0086] 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. From the viewpoint of providing a photosensitive element with even better photosensitivity and resolution during resist pattern formation, 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%. HABI(C1) may also be a compound having only alkoxy groups having 3 or more carbon atoms as substituents on the aryl group.

[0087] HABI(C1) may not contain halogen atoms in its molecular structure. In this case, depending on what other components the photosensitive resin composition contains, it becomes possible to make the photosensitive element halogen-free or low-halogen.

[0088] HABI(C1) may contain, for example, a compound represented by the following general formula (6).

[0089]

[0090] [In general formula (6), R １０ ~R１５ Each of these independently represents a hydrogen atom or an alkoxy group with a carbon chain of 3 to 8 atoms, and f to k represent integers of 0 or 1 to 5. Ｘ At least two of them are alkoxy groups.

[0091] 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.

[0092] The compound represented by the above general formula (6) may more specifically be the compound represented by the following general formula (6-1).

[0093]

[0094] [In general formula (6-1), R １０ and R １３ Each of these is an alkoxy group having three or more carbon atoms.

[0095] In general formula (6-1), R １０ and R １３ Each of these is an alkoxy group with 3 or more carbon atoms. １０ and R １３ Each of these 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, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, and n-octyloxy groups.

[0096] 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.

[0097] 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).

[0098] The photosensitive resin composition may contain, in addition to a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), a sensitizing dye, a hydrogen-donating compound, and other components.

[0099] [Sensitizing Dyes] The photosensitive resin composition of this embodiment may contain at least one sensitizing dye. Examples of sensitizing dyes 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.

[0100] 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 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.

[0101] The content of the sensitizing dye in the photosensitive resin composition is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 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.

[0102] The pyrazoline compound is preferably at least one selected from the group consisting of compounds represented by the following general formula (7) and compounds represented by the following general formula (8).

[0103]

[0104] In general formula (7), R １６ ~R １８ Each 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 independently represents an integer from 0 to 5, and the sum of l, m, and n is from 1 to 6. When the sum of l, m, and n is 2 or more, multiple R groups exist. １６ ~R １８ They may be the same or different from each other.

[0105] In general formula (7), R １６ ~R １８ 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.

[0106] The pyrazoline compound represented by general formula (7) 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 l=0 in the above general formula (7) 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.

[0107]

[0108] In general formula (8), R １９ ~R ２１ 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. Also, each of o, p, and q independently represents an integer from 0 to 5, and the sum of o, p, and q is from 1 to 6. When the sum of o, p, and q is 2 or more, there are multiple R １９ ~R ２１ They may be the same or different from each other.

[0109] In general formula (8), R １９ ~R ２１At 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.

[0110] Furthermore, the pyrazoline compound represented by general formula (8) 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-phenyl-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-phenyl Pyrazoline compounds corresponding to w=0 in the above general formula (8), such as ru-3,5-bis(4-tert-butylphenyl)-pyrazoline and 1,5-diphenyl-3-(4-tert-butylphenyl)-pyrazoline; and in the above general formula (8), such as 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)-pyrazoline and 1-phenyl-3-(4-biphenyl)-5-(4-tert-octylphenyl)-pyrazoline, p=1, R ２０ Examples include pyrazoline compounds, which have a phenyl group.

[0111] The anthracene compound preferably includes a compound represented by the following general formula (9).

[0112]

[0113] In general formula (9), R ２２ and R２３ 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. ２４ ~R ３１ 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.

[0114] R in general formula (9) ２２ and R ２３ Examples include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. ２２ and R ２３ Examples of such combinations include combinations of ethyl groups, combinations of propyl groups, and combinations of butyl groups.

[0115] R ２４ ~R ３１ 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.

[0116] R ２２ and R ２３is preferably an alkyl group having 1 to 4 carbon atoms independently. R ２４ R ２５ R ２６ R ２７ R ２８ R ２９ R ３０ and R ３１ is preferably a hydrogen atom.

[0117] Specific examples of the compound represented by the general formula (9) include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, and the like.

[0118] The triarylamine compound is preferably at least one kind of compound represented by the following general formula (10).

[0119]

[0120] In the general formula (10), R ３２ R ３３ and R ３４ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. r, s, and t represent integers of 0 to 5 selected such that the value of r + s + t is 1 or more. When r is 2 or more, a plurality of R ３２ may be the same or different. When s is 2 or more, a plurality of R ３３ may be the same or different. When t is 2 or more, a plurality of R ３４ may be the same or different. In the general formula (10), R ３２ R ３３ and R ３４ are preferably hydrogen atoms.

[0121] [Hydrogen donor compound] The photosensitive resin composition preferably contains at least one kind of hydrogen donor compound. Examples of the hydrogen donor compound 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.

[0122] When the photosensitive resin composition contains a hydrogen-donating compound, 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 hydrogen-donating compound as foreign matter in the photosensitive element tends to be suppressed.

[0123] [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).

[0124] [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, ethanol, and isopropyl alcohol; ketone solvents such as acetone, methyl ethyl ketone, and cyclopentanone; 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").

[0125] From the viewpoint of reducing environmental impact, it is preferable that the organic solvent contains as little toluene as possible. HABI(C1) has superior solvent solubility compared to conventional HABI, and therefore exhibits sufficient solubility in alcohol solvents, ketone solvents, and mixed solvents thereof even without toluene. The organic solvent may be isopropyl alcohol, acetone, cyclopentanone, or mixed solvents thereof.

[0126] [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.

[0127] Figure 1 shows one embodiment of a photosensitive element. In the photosensitive element 10 shown in Figure 1, a support film 2, a photosensitive resin composition layer 4 which is a coating film of a photosensitive resin composition, and a protective film 6 are laminated in this order. The photosensitive element 10 can be obtained, for example, as follows. A coating liquid which is a photosensitive resin composition containing an organic solvent is applied to the support film 2 to form a coating layer, and this is dried to form a photosensitive resin composition layer 4. Next, the side of the photosensitive resin composition layer 4 opposite to the support film 2 is covered with the protective film 6 to obtain a photosensitive element 10 comprising a support film 2, a photosensitive resin composition layer 4 laminated on the support film 2, and a protective film 6 laminated on the photosensitive resin composition layer 4. The photosensitive element 10 does not necessarily have to include the protective film 6.

[0128] As the support film, polymer films with heat resistance and solvent resistance, such as polyethylene terephthalate, polyester, polypropylene, and polyethylene, can be used.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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. Furthermore, it is preferable that the toluene content of the photosensitive resin composition layer be less than 5 ppm. The toluene content of the photosensitive resin composition layer is a value measured by GC-MS under the following conditions for the photosensitive resin composition layer, i.e., the dried coating film of the photosensitive resin composition.

[0136] [Measurement conditions for toluene content in photosensitive resin composition layer] Apparatus: Shimadzu Corporation "GCMS QP-2020NX" Carrier gas: He 1.0 mL / min Column: HP-5MS (5% phenyl-95% methylpolysiloxane), inner diameter 0.25 mm x 30 m, film thickness 0.25 μm Oven temperature: Held at 40°C for 5 minutes, then increased to 300°C at 20°C / min Mode: SIM (m / z; 91)

[0137] Furthermore, the chlorine atom content of the photosensitive resin composition layer is preferably less than 900 ppm. Moreover, the chlorine atom content of the photosensitive resin composition layer may be 500 ppm or less, 100 ppm or less, 50 ppm or less, 30 ppm or less, or 10 ppm or less. Since HABI(C1) does not contain chlorine atoms, it is possible to achieve low halogenation and even halogen-free photosensitive resin compositions. The chlorine atom content of the photosensitive resin composition layer is a value measured by combustion tube decomposition-ion chromatography under the following conditions for the photosensitive resin composition layer, i.e., the dried coating film of the photosensitive resin composition.

[0138] [Measurement conditions for chlorine atom content in photosensitive resin composition layer] 1) Sample combustion unit: Mitsubishi Chemical Analytec "AQF-100" 2) Ion chromatograph: Thermo Fisher Scientific "ICS-1600" Detector: Electrical conductivity detector Column: Thermo Scientific "Dionex IonPac AS12A" Eluent: 2.7 mmol / L sodium carbonate / 0.3 mmol / L sodium bicarbonate Flow rate: 1.2 mL / min Internal standard: Tartrate ion (5 mg / kg)

[0139] In one embodiment, the thickness of the photosensitive resin composition layer in the photosensitive element is 10 μm or less. As described above, in one embodiment, the photopolymerization initiator (C) contains HABI(C1), resulting in a photosensitive element with excellent photosensitivity and resolution. Therefore, the photosensitive resin composition layer is relatively thin and can be suitably used in fine applications where the line and space width is 3 μm or less.

[0140] The transmittance of the photosensitive resin composition layer to ultraviolet light is preferably 5% to 75%, more preferably 10% to 65%, and particularly preferably 15% to 55% for ultraviolet light in the wavelength range of 350 nm to 420 nm. When the transmittance is 5% or higher, sufficient adhesion tends to be easily obtained. When it is 75% or lower, sufficient resolution tends to be easily obtained. 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.

[0141] 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.

[0142] In one embodiment, the photosensitive element may include a barrier layer between the photosensitive resin composition layer and the support film.

[0143] [Barrier Layer] The barrier layer has an oxygen permeability of 6,000 mL / m³ under conditions of 20°C and 65% RH. ２・It may be below day・MPa (converted value for a film thickness of 25 μm). The barrier layer may be a layer formed using a resin composition for forming a barrier layer. The resin composition for forming a barrier layer in the present embodiment may contain a water-soluble resin. Further, the barrier layer may have water solubility and may have solubility in a developer. From the viewpoint of further improving the gas barrier property of the barrier layer, the adhesive strength between the support film and the barrier layer may be smaller than the adhesive strength between the barrier layer and the photosensitive resin composition layer. In this case, when peeling the support film from the photosensitive element, unintentional peeling between the barrier layer and the photosensitive resin composition layer can be suppressed.

[0144] The barrier layer may contain a water-soluble resin. Here, the "water-soluble resin" means a resin having a solubility of 5 g / 100 mL - C ６ H １４ or less with respect to 100 mL of hexane at 25°C. This solubility can be calculated by mixing hexane at 25°C and the dried water-soluble resin and examining the presence or absence of turbidity. Specifically, prepare sample 1 obtained by putting a mixed solution of the dried water-soluble resin A (g) and 100 mL of hexane into a colorless and transparent glass container with a ground glass stopper, and sample 2 obtained by putting only 100 mL of hexane. Then, after thoroughly shaking the samples in the glass container, confirm that the bubbles have disappeared. Immediately after confirmation, place the two containers side by side under diffused daylight or light equivalent thereto, and compare the state of the liquid in sample 1 with the state of the liquid in sample 2. Compare sample 1 with sample 2, and when it is observed that sample 1 begins to become cloudier or floating of solid content begins to be observed, the added amount A (g) at that time is defined as the solubility of the water-soluble resin with respect to 100 mL of hexane at 25°C.

[0145] Examples of water-soluble resins include polyvinyl alcohol, polyvinylpyrrolidone, and water-soluble polyimides. From the viewpoint of further improving the gas barrier properties of the barrier layer and further suppressing the deactivation of radicals generated by the active light used in exposure, the water-soluble resin may contain polyvinyl alcohol. Polyvinyl alcohol can be obtained, for example, by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. The degree of saponification of the polyvinyl alcohol may be 50 mol% or more, 70 mol% or more, or 80 mol% or more. The upper limit of the degree of saponification is 100 mol%. Including polyvinyl alcohol with a degree of saponification of 50 mol% or more tends to further improve the gas barrier properties of the barrier layer and further improve the resolution of the formed resist pattern. In this specification, "degree of saponification" refers to the value measured in accordance with JIS K 6726 (1994) (Test method for polyvinyl alcohol) as specified in the Japanese Industrial Standards.

[0146] Polyvinyl alcohol may be used in combination of two or more types with different degrees of saponification, viscosity, degree of polymerization, and modified species. The average degree of polymerization of the polyvinyl alcohol may be 300 to 5,000, 300 to 3,500, or 300 to 2,000. In addition, the water-soluble resin may be used alone or in combination of two or more types. The water-soluble resin may, for example, contain polyvinyl alcohol and polyvinylpyrrolidone. In this case, the mass ratio of polyvinyl alcohol to polyvinylpyrrolidone (PVA:PVP) may be 40:60 to 90:10, 50:50 to 90:10, or 60:40 to 90:10.

[0147] The content of the water-soluble resin in the barrier layer-forming resin composition may be 50 to 300 parts by mass, 60 to 250 parts by mass, 70 to 200 parts by mass, 80 to 150 parts by mass, or 80 to 125 parts by mass per 500 parts by mass of water, from the viewpoint of improving gas barrier properties.

[0148] The content of the water-soluble resin in the barrier layer may be 99.0 to 99.95% by mass, 99.3 to 99.9% by mass, or 99.5 to 99.8% by mass, based on the total solid content of the barrier layer, from the viewpoint of improving gas barrier properties, improving peelability between the support film and the barrier layer, and improving solubility in the developing solution.

[0149] The barrier layer may contain a leveling agent. The leveling agent is oriented on the surface of the coating film and equalizes the tension of the coating film surface. Examples of leveling agents include acrylic polymers, vinyl polymers, silicone polymers, and fluorine polymers. From the viewpoint of transferability to photosensitive elements and solubility in developing solutions, the leveling agent is preferably an acrylic polymer. The acrylic polymer preferably contains a copolymer having structural units selected from the group consisting of butyl (meth)acrylate, isobutyl (meth)acrylate, and terminal methoxy group EO-modified (meth)acrylate, from the viewpoint of maintaining an appropriate level of adhesion between the barrier layer and the support film, making the adhesive force between the support film and the barrier layer less than the adhesive force between the barrier layer and the photosensitive resin composition layer, while suppressing unintended peeling between each layer, and from the viewpoint of easily suppressing the occurrence of defects on the surface of the barrier layer when forming the barrier layer on the support film (making it less likely to repel). It is more preferably a copolymer having structural units derived from butyl (meth)acrylate and isobutyl (meth)acrylate, and even more preferably a copolymer having structural units derived from butyl (meth)acrylate, isobutyl (meth)acrylate, and terminal methoxy group EO-modified (meth)acrylate.

[0150] The content of each structural unit constituting the acrylic polymer may be in the following ranges, for example, based on the total amount of structural units: The content of structural units derived from butyl (meth)acrylate may be 2 to 20% by mass, 5 to 15% by mass, or 5 to 10% by mass, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing the damage of the barrier layer when the support film is peeled off. The content of structural units derived from isobutyl (meth)acrylate may be 40 to 80% by mass, 50 to 70% by mass, or 55 to 65% by mass, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing the damage of the barrier layer when the support film is peeled off. The content of structural units derived from terminal methoxy group EO-modified (meth)acrylate may be 15 to 45% by mass, 20 to 40% by mass, or 25 to 35% by mass, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing the damage of the barrier layer when the support film is peeled off. Furthermore, the weight-average molecular weight of the acrylic polymer may be 10,000 to 40,000 or 10,000 to 20,000, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing the damage of the barrier layer when the support film is peeled off.

[0151] The leveling agent content in the barrier layer may be 0.05 to 1.0% by mass, 0.1 to 0.7% by mass, or 0.2 to 0.5% by mass, based on the total solid content of the barrier layer, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing damage to the barrier layer when the support film is peeled off.

[0152] The barrier layer may contain an ultraviolet absorber. The ultraviolet absorber (UV absorber) is a compound having a light absorption band in the wavelength range of 300 nm to 400 nm. The ultraviolet absorber may be water-soluble. From the viewpoint of further improving resolution, the ultraviolet absorber may have a maximum absorption wavelength in the wavelength range of 250 nm to 500 nm. By including these ultraviolet absorbers, the resolution can be improved.

[0153] The i-ray absorptivity of the UV absorber may be 5-95%, 10-90%, or 15-75%. The i-ray absorptivity can be measured by a UV-Vis spectrophotometer.

[0154] The above-mentioned UV absorbers may be used individually or in combination of two or more types. Furthermore, the solubility of the UV absorber in water at 20°C is set at 0.01 g / 100 mL-H, from the viewpoint of suppressing aggregation and precipitation of the UV absorber in the barrier layer. ２ O or more, 0.1g / 100mL-H ２ 0 or more, or 1 g / 100 mL - H ２ It may be 0 or more.

[0155] Examples of UV absorbers include oxybenzophenone compounds, triazole compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, diphenyl acrylate compounds, cyanoacrylate compounds, diphenylcyanoacrylate compounds, and iron or nickel complex salt compounds. Among these, from the viewpoint of further improving resolution, oxybenzophenone compounds and benzophenone compounds are preferred, benzophenone sulfonic acid compounds are more preferred, and oxybenzophenone sulfonic acid compounds are even more preferred. A "benzophenone sulfonic acid compound" is a compound having a sulfo group in a benzophenone compound, and the benzophenone sulfonic acid compound may be a hydrate. It is hypothesized that these compounds, by having a hydrophilic sulfo group in the benzophenone skeleton, allow the benzophenone skeleton to have a high affinity for the resist, while the sulfo group has a high affinity for the barrier layer, thereby achieving both high resolution and barrier layer removalability. Furthermore, among oxybenzophenone compounds, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate represented by the following formula (11) is preferred.

[0156]

[0157] The barrier layer of this embodiment may have an absorbance of 0.01 to 2.0 or 0.1 to 1.0 for light at a wavelength of 365 nm. When the absorbance is 0.01 or higher, better resolution tends to be obtained, and when it is 2.0 or lower, the resist pattern shape of the resulting resist pattern tends to be better. The absorbance of the barrier layer can be measured, for example, using a UV spectrophotometer (Hitachi, Ltd. "Spectrophotometer U-3310"). The measurement is performed by placing a laminated film with a barrier layer of any thickness formed on a support film on the measurement side, placing the support film on the reference side, and continuously measuring from wavelengths of 300 to 700 nm in absorbance mode, and reading the value at wavelength 365 nm.

[0158] The barrier layer forming resin composition of this embodiment may contain alcohols having 3 or more carbon atoms. The alcohols having 3 or more carbon atoms may be monohydric alcohols or polyhydric alcohols (excluding the polyhydric alcohol compound plasticizer described later). The alcohols having 3 or more carbon atoms may contain at least one selected from the group consisting of compounds represented by the following chemical formulas (12) to (14) and compounds represented by the following general formula (15). By including these alcohols having 3 or more carbon atoms, the peelability between the barrier layer and the support film can be improved. Therefore, when peeling the support film from the photosensitive element, unintended peeling between the barrier layer and the photosensitive resin composition layer can be suppressed, and the decrease in gas barrier properties and the decrease in resolution caused by such unintended peeling can be suppressed.

[0159]

[0160]

[0161]

[0162]

[0163] In general formula (15), R ３５ R represents an alkyl group, ３６ R indicates an alkylene group. ３５ The base and R ３６The sum of the number of carbon atoms in the group is 3 or more. Also, R ３５ The base and R ３６ The sum of the number of carbon atoms with the group may be 10 or less, 8 or less, 7 or less, or 5 or less, from the viewpoint of further improving affinity with water. ３５ The alkyl group represented by may be an alkyl group having 1 to 4 carbon atoms, R ３６ The alkylene group represented by may be an alkylene group having 1 to 3 carbon atoms. Also, the alcohols with 3 or more carbon atoms represented by general formula (15) may be 2-butoxyethanol or 1-methoxy-2-propanol.

[0164] The above-mentioned alcohols having 3 or more carbon atoms may be used individually or in combination of two or more. Furthermore, the solubility of the alcohols having 3 or more carbon atoms in water at 20°C is set at 300 mL / 100 mL-H from the viewpoint of further suppressing layer separation in the barrier layer. ２ O or more, 500mL / 100mL-H ２ 0 or more, or 1000 mL / 100 mL - H ２ It may be 0 or more.

[0165] In this specification, "solubility of alcohols with 3 or more carbon atoms in water at 20°C" can be calculated by mixing the alcohols with water at 20°C and checking for turbidity. Specifically, sample 3 is prepared by placing a mixture of A mL of the alcohols and 100 mL of water in a colorless, transparent glass container with a ground-glass stopper, and sample 4 is prepared by placing only water (100 mL) in the mixture. Next, samples 3 and 4 in the glass containers are shaken thoroughly, and it is confirmed that the bubbles have disappeared. Immediately after confirmation, the two containers are placed side by side under diffuse daylight or equivalent light, and the state of the liquid in sample 3 and the state of the liquid in sample 4 are compared. Comparing sample 3 and sample 4, the amount of alcohols added A mL when sample 3 is observed to be more cloudy is defined as the solubility of the alcohols in water at 20°C.

[0166] The content of alcohols having 3 or more carbon atoms in the barrier layer forming resin composition of this embodiment may be 100 to 500 parts by mass, or 125 to 450 parts by mass, per 500 parts by mass of water. When the content is 100 parts by mass or more, the peelability between the formed barrier layer and the support film tends to improve, and when it is 500 parts by mass or less, the solubility of the water-soluble resin improves, and the barrier layer tends to form more easily.

[0167] The content of alcohols having 3 or more carbon atoms in the barrier layer of this embodiment may be greater than 0% by mass and 2.0% by mass or less, 0.001 to 2.0% by mass, or 0.005 to 1.0% by mass, based on the total amount of the barrier layer (total amount of solids in the barrier layer forming resin composition that forms the barrier layer). When the content is 2.0% by mass or less, the diffusion of alcohols in subsequent processes tends to be suppressed, and when it is 0.001% by mass or more, the peelability between the barrier layer and the support film tends to be improved.

[0168] Furthermore, the barrier layer and the resin composition for forming the barrier layer of this embodiment may contain known additives such as plasticizers and surfactants, to the extent that they do not impede the effects of the present disclosure. They may also contain peel-off accelerators, to the extent that they do not impede the effects of the present disclosure.

[0169] The barrier layer in the photosensitive element of this embodiment can be formed, for example, by applying the barrier layer-forming resin composition of this embodiment onto a support film and drying it. When the barrier layer-forming resin composition contains a leveling agent, applying it onto a support film tends to cause the leveling agent to become unevenly distributed on the surface side of the support film within the coating. This tends to lower the surface tension of the barrier layer-forming resin composition, making it easier to suppress repelling. Furthermore, the uneven distribution of the leveling agent on the surface side of the support film within the barrier layer tends to reduce the adhesion between the support film and the barrier layer.

[0170] The thickness of the barrier layer is not particularly limited. From the viewpoint of ease of removal of the barrier layer, the thickness of the barrier layer may be 12 μm or less, 10 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less. Also, from the viewpoint of ease of formation and resolution of the barrier layer, the thickness of the barrier layer may be 1.0 μm or more, 1.5 μm or more, 2 μm or more, 3 μm or more, or 4 μm or more. Furthermore, from the viewpoint of suppressing the migration of the barrier layer, the thickness of the barrier layer may be 2 μm or more, 3 μm or more, or 4 μm or more.

[0171] 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.

[0172] The photosensitive element of one embodiment can be suitably used, for example, as a material for forming a resist pattern.

[0173] [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.

[0174] (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.

[0175] 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.

[0176] (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, causing the exposed area to photocur and form a latent image. 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. Furthermore, if the photosensitive element includes a barrier layer between the photosensitive resin composition layer and the support film, the active light can be irradiated through the barrier layer after the support film is removed, regardless of the active light transmittance of the support film.

[0177] One exposure method is to irradiate an active light in an image-like manner through a negative or positive mask pattern called artwork (mask exposure method). Alternatively, a direct drawing exposure method such as LDI (Laser Direct Imaging) exposure or DLP (Digital Light Processing) exposure may be used to irradiate an active light in an image-like manner.

[0178] 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.

[0179] 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.

[0180] (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 barrier 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.

[0181] 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.

[0182] The developer is appropriately selected according to the composition of the photosensitive resin composition. Examples of developers include alkaline aqueous solutions, aqueous developers, and organic solvent-based developers.

[0183] 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.

[0184] 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.

[0185] Aqueous developers are, for example, developers consisting of water or an alkaline aqueous solution and one or more organic solvents. Examples of bases in the alkaline aqueous solution, in addition to those mentioned above, include borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diamino-2-propanol, and morpholine. The pH of the aqueous developer is preferably as low as possible while still allowing sufficient development, preferably between 8 and 12, and more preferably between 9 and 10.

[0186] Examples of organic solvents used in aqueous developers include acetone, ethyl acetate, alkoxyethanol having alkoxy groups with 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. These can be used individually or in combination of two or more. The concentration of the organic solvent in the aqueous developer is usually preferably 2% to 90% by mass. The temperature can be adjusted according to the alkaline developing properties. Small amounts of surfactants, defoamers, etc., can also be added to the aqueous developer.

[0187] 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.

[0188] 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.

[0189] [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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] As described above, the photosensitive element of one embodiment has excellent light sensitivity and resolution, making it suitable for applications involving the formation of fine patterns with line and space widths of 3 μm or less. Specifically, it is suitable for semiconductor package substrate applications as well as applications such as so-called interposers. An interposer is a term used to refer to a component, for example, that is installed between the package substrate and the semiconductor chip in a conventional semiconductor package and is used for information transmission between semiconductor chips and to connect the semiconductor chip and the package substrate. It is a component that requires the formation of finer patterns compared to conventional package substrates.

[0196] Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> A photosensitive element comprising a support film and a photosensitive resin composition layer, wherein the thickness of the photosensitive resin composition layer is 10 μm or less, and the photosensitive resin composition layer comprises 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.

[0197] <2> The photosensitive element according to <1>, comprising a barrier layer between the photosensitive resin composition layer and the support film.

[0198] <3> The photosensitive element according to <1> or <2>, wherein the toluene content of the photosensitive resin composition layer is less than 5 ppm.

[0199] <4> The photosensitive element according to any one of <1> to <3>, wherein the chlorine atom content of the photosensitive resin composition layer is less than 900 ppm.

[0200] <5> A photosensitive element according to any one of <1> to <4> above, which is a material for forming a resist pattern.

[0201] <6> A photosensitive element according to any one of <1> to <5> above, which is a material for forming a resist pattern in an interposer.

[0202] <7> A method for forming a resist pattern, comprising: a lamination step of laminating a photosensitive resin composition layer of any one of <1> to <7> 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.

[0203] <8> The method for forming a resist pattern according to <7>, wherein the resist pattern is a resist pattern in an interposer.

[0204] <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 <7> or <8> above to form a conductor pattern.

[0205] 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.

[0206] 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.

[0207] 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

[0208] [Preparation of Binder Polymer (A-1)] 96.1 parts by mass of acrylic acid, 339.9 parts by mass of styrene, 4.6 parts by mass of t-butyl peroxy-2-ethylhexanoate ("Perbutyl O" manufactured by NOF Corporation), and 128.6 parts by mass of propylene glycol monomethyl ether were mixed to obtain a monomer mixture. In addition, 4.6 parts by mass of t-butyl peroxy-2-ethylhexanoate ("Perbutyl O" manufactured by NOF Corporation) was dissolved in 37.7 parts by mass of propylene glycol monomethyl ether to obtain an initiator solution.

[0209] 221 parts by mass of propylene glycol monomethyl ether was added to a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube. The mixture was stirred under a nitrogen atmosphere while gas purging, and the temperature was raised to 98°C. Next, the monomer mixture obtained earlier was added dropwise to the flask over 2 hours while maintaining the same temperature. After stirring at 98°C for 2 hours, the initiator solution obtained earlier was added, and the mixture was stirred at the same temperature for a further 3 hours. While continuing to stir, the temperature inside the flask was raised to 105°C over 20 minutes, and then stirred for a further 2 hours. 168 parts by mass of propylene glycol monomethyl ether was added, and the mixture was cooled to room temperature while stirring to obtain a binder polymer (A-1) solution.

[0210] [Production of Barrier Layer Forming Resin Composition] A barrier layer forming resin composition was obtained by mixing each component shown in Table 1 in the amounts (unit: parts by mass) shown in the same table. Specifically, the water-soluble resin was slowly added to a solvent at room temperature, stirred for 1 hour after the entire amount was added, and then the leveling agent was mixed in to dissolve it uniformly to obtain the barrier layer forming resin composition. Note that the amounts of water-soluble resin in Table 1 are the amounts in solid content.

[0211]

[0212] Details of each component in Table 1 are as follows: *1: HC-100G (polyvinyl alcohol, manufactured by Taisei Chemical Co., Ltd., product name: Maltite HC-100G, solid content 13.5% by mass) *2: K-30 (polyvinylpyrrolidone, manufactured by Nippon Shokubai Co., Ltd., product name) *3: WS-314 (acrylic polymer, manufactured by Kyoeisha Chemical Co., Ltd., product name, components: 48% by mass of acrylic polymer and 52% by mass of 3-methoxy-3-methyl-1-butanol, composition of acrylic polymer: copolymer of approximately 6.89 mol% butyl (meth)acrylate, approximately 61.4 mol% isobutyl (meth)acrylate and approximately 31.7 mol% terminal methoxy group EO-modified (meth)acrylate)

[0213] Examples 1-3 and Comparative Example 1 [Production of Photosensitive Elements] A photosensitive resin composition was produced by blending and mixing each component in the proportions shown in Table 2 below. For components other than the solvent in Table 2, the amounts are calculated on a solid content basis for components that are solutions. A photosensitive element was produced using the obtained photosensitive resin composition in the following manner, and various evaluation tests were conducted. The various conditions and evaluation results for the photosensitive element are shown in the table.

[0214] The details of each component in Table 2 are as follows: • Binder polymer (A-1): Binder polymer (A-1) obtained above. • Photopolymerizable compound (B-1): 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane, the average total number of ethylene oxide groups per molecule is 10 (FA-321M, manufactured by Resonaq Corporation). • Photopolymerizable compound (B-2): 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane, the average total number of ethylene oxide groups per molecule is 2.6 (Light Ester BP-2EM, manufactured by Kyoeisha Chemical Co., Ltd.). • Photopolymerizable compound (B-3): Polyalkylene glycol di(meth)acrylate represented by the following general formula (4-1), the average sum of e2 and e3 is 6, and the average value of d3 is 12 (FA-024M, manufactured by Resonaq Corporation).

[0215]

[0216] HABI(C1-1): In the following general formula (6-1), R １０and R １３ Compounds in which R is an n-propoxy group, HABI(C1-2): In the following general formula (6-1), R １０ and R １３ Compounds in which is an n-hexyloxy group / Comparative HABI (1): In the following general formula (6-1), R １０ and R １３ Compounds in which R is a methoxy group - comparative HABI (2): In the following general formula (6-1), R １０ and R １３ Compound OXE-02, which contains a chloro group: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone-1-(O-acetyloxime) (BASF "Irgacure OXE02")

[0217]

[0218] • Hydrogen-donating compound: Leucocrystal violet (tris[4-(dimethylamino)phenyl]methane) (Yamada Chemical Co., Ltd.) • Dye: Malachite green (Osaka Organic Chemical Industry Co., Ltd.) • Adhesion-improving agent: Mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (Sanwa Chemicals Co., Ltd. "Q-SF-808H") • Antioxidant (1): DIC Corporation "Q-TBC-5P", tertiary butylcatechol • Antioxidant (2): 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (Adeka Corporation "LA-7RD")

[0219]

[0220] [Manufacturing of Photosensitive Element] The photosensitive resin composition obtained above was applied onto a support film (*4). It was dried in a hot air convection dryer at 100°C to form a photosensitive resin composition layer with a thickness of 6 μm. Subsequently, a protective film (*5) was laminated onto the photosensitive resin composition layer to obtain a photosensitive element. For Example 3, which has a barrier layer, the barrier layer forming resin composition obtained above was applied onto a support film (*4), dried in a hot air convection dryer at 110°C to form a barrier layer with a thickness of 5 μm, and then the photosensitive resin composition was applied onto the barrier layer, and the photosensitive element was obtained in the same manner as above. Support film (*4): 16 μm thick polyethylene terephthalate film (Toray Industries, Inc. "FS-31") Protective film (*5): 20 μm thick polyethylene film (Tamapoly Co., Ltd., product name "NF-15A")

[0221] [Measurement of Chlorine Atom Content in Photosensitive Composition Layer] The support film and protective film were peeled off from the photosensitive element (the barrier layer was also peeled off in the case of the photosensitive element in Example 3) to obtain a test piece which was a dried coating of the photosensitive resin composition. The chlorine atom content of the test piece was measured by combustion tube decomposition-ion chromatography under the following conditions: 1) Sample combustion chamber apparatus: Mitsubishi Chemical Analytec "AQF-100" 2) Ion chromatograph apparatus: Thermo Fisher Scientific "ICS-1600" Detector: Electrical conductivity detector Column: Thermo Scientific "Dionex IonPac AS12A" Eluent: 2.7 mmol / L sodium carbonate / 0.3 mmol / L sodium bicarbonate Flow rate: 1.2 mL / min Internal standard: Tartrate ion (5 mg / kg)

[0222] [Measurement of Toluene Content in Photosensitive Composition Layer] The support film and protective film were peeled off from the photosensitive element (the barrier layer was also peeled off in the case of the photosensitive element in Example 3) to obtain a test piece which was a dried coating of the photosensitive resin composition. The toluene content of the test piece was measured by GC-MS under the following conditions. Apparatus: Shimadzu Corporation "GCMS QP-2020NX" Carrier gas: He 1.0 mL / min Column: HP-5MS (5% phenyl-95% methylpolysiloxane), inner diameter 0.25 mm × 30 m, film thickness 0.25 μm Oven temperature: Held at 40°C for 5 minutes, then heated to 300°C at 20°C / min Mode: SIM (m / z; 91)

[0223] [Measurement of shortest development time] A laminate 1 was obtained by laminating a photosensitive element onto a copper layer substrate (Ra: 40 nm) while peeling off the protective film of the photosensitive element, so that the photosensitive resin composition layer of the photosensitive element was in contact with the copper surface of the substrate. Lamination was performed using a 110°C heat roll under conditions of a pressing pressure of 0.4 MPa and a roll speed of 1.5 m / min. The support film was peeled off (for the photosensitive element of Example 3, the support film and barrier layer were peeled off), and this was used as a test piece. The unexposed photosensitive resin composition layer on the test piece was spray-developed at a pressure of 0.10 MPa using a 1.0 mass% sodium carbonate aqueous solution at 30°C, and the shortest time at which it was visually confirmed that the unexposed photosensitive resin composition layer had been completely removed was defined as the shortest development time.

[0224] [Measurement of exposure amount] After placing a 41-step tablet (manufactured by Resonac Corporation) on the support film of the 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. 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. The exposure amount was changed and this operation was repeated, and the exposure amount at which the number of remaining steps after development of the 41-step tablet was 12 was measured. In Example 3, the support film of the laminate 1 was peeled off, and a 41-step tablet was placed on the barrier layer and exposed in the same manner as above. After that, development was performed in the same manner as above.

[0225] [Resolution Evaluation] Using a glass-chromium type phototool (*6) on the laminate 1, and a projection exposure apparatus (manufactured by Canon Inc., product name "FPA-3000iW") with a high-pressure mercury lamp (365 nm) as the light source, exposure was performed at an exposure level that resulted in 12 remaining steps after development of the previously measured 41-step tablet. The focus position was set to the center 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. The resolution was defined as the minimum x value at which a clear resist pattern was obtained in which the space areas (unexposed areas) were cleanly removed and there was no pattern distortion, meandering, or missing parts in the line areas (exposed areas). This test was performed three times, and the average value of x was used for evaluation.

[0226] - Photo tool (*6): Line width / Space width = x / x, where x is in 1 μm increments from 1 μm to 10 μm.

[0227] As shown in Table 2, the photosensitive elements of Examples 1 to 3 had very low chlorine and toluene content in the photosensitive resin composition layer. They also exhibited high photosensitivity, enabling high-resolution pattern formation. Comparative Examples 1 and 2, which contained HABI having a chloro group as the photopolymerization initiator (C), had a very high chlorine atom content in the photosensitive resin composition layer due to the chloro group contained in HABI. Furthermore, their photosensitivity was inferior to that of the Examples. Comparative Example 3, which contained OXE-02 as the photopolymerization initiator (C), had a low chlorine content in the photosensitive resin composition layer, but the resolution was lower compared to the Examples. Comparative Example 4, which contained HABI having a methoxy group as the photopolymerization initiator (C), exhibited lower sensitivity and resolution compared to the Examples.

[0228] 10: Photosensitive element, 2: Support film, 4: Photosensitive resin composition layer, 6: Protective film

Claims

1. A photosensitive element comprising a support film and a photosensitive resin composition layer, wherein the thickness of the photosensitive resin composition layer is 10 μm or less, the photosensitive resin composition layer comprises a photosensitive resin composition comprising a binder polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), and 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 element according to claim 1, comprising a barrier layer between the photosensitive resin composition layer and the support film.

3. The photosensitive element according to claim 1, wherein the toluene content of the photosensitive resin composition layer is less than 5 ppm.

4. The photosensitive element according to claim 1, wherein the chlorine atom content of the photosensitive resin composition layer is less than 900 ppm.

5. The photosensitive element according to claim 1, which is a material for forming a resist pattern.

6. The photosensitive element according to claim 1, which is a material for forming a resist pattern in an interposer.

7. A method for forming a resist pattern, comprising: a lamination step of laminating a photosensitive resin composition layer of a photosensitive element according to claim 1 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.

8. The method for forming a resist pattern according to claim 7, wherein the resist pattern is a resist pattern in an interposer.

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 7 or 8 to form a conductor pattern.

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