Mixture of (METH)acrylate compounds, photosensitive resin composition, and photosensitive element

Abstract

To provide a mixture of (meth)acrylate compounds capable of forming a resist pattern which achieves both photosensitivity and releasability, a photosensitive resin composition comprising the mixture, and a photosensitive element.SOLUTION: Provided is a mixture of (meth)acrylate compounds containing a compound represented by the following formula (1) and a compound represented by the following formula (2). In formulas (1) and (2), R1 and R2 each independently represent a hydrogen atom or a methyl group; L1 and L2 each independently represent an alkylene group having 2 to 6 carbon atoms; m+n satisfies 2 to 40; and Y represents a methylene group or an isopropylidene group. In formula (2), X represents a residue of a monoisocyanate compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a mixture of (meth)acrylate compounds, a photosensitive resin composition containing the mixture, and a photosensitive element. [Background technology]

[0002] In the field of wiring board manufacturing, photosensitive resin compositions and photosensitive elements comprising a layer formed on a support using the photosensitive resin composition (hereinafter also referred to as a "photosensitive layer") are widely used as resist materials used in etching or plating processes.

[0003] The wiring board is manufactured, for example, by the following procedure. First, the photosensitive layer of the photosensitive element is laminated on a circuit-forming substrate (photosensitive layer forming step). Next, a predetermined portion of the photosensitive layer is exposed to light to form a photocured portion (exposure step). At this time, the support is peeled off before or after exposure. Thereafter, the area of ​​the photosensitive layer other than the photocured portion is removed from the substrate, and a resist pattern, which is a cured product of the photosensitive resin composition, is formed on the substrate (development step). Next, the obtained resist pattern is used as a resist and subjected to etching or plating to form a conductor pattern on the substrate (circuit forming step), and finally the resist is peeled off and removed (peeling step).

[0004] Conventionally, a method of exposure through a photomask using a mercury lamp as a light source has been known as an exposure method. In recent years, a direct imaging exposure method called LDI (Laser Direct Imaging) has been used as an exposure method that does not require a photomask, in which digital data of a pattern is directly drawn on a photosensitive layer. This direct imaging exposure method has better alignment accuracy than exposure methods using a photomask, and can produce high-definition patterns, so it is being introduced for the production of high-density packaging substrates.

[0005] In general, in the exposure step, it is desired to shorten the exposure time in order to improve production efficiency. However, in the above-mentioned direct writing exposure method, a monochromatic light such as a laser is used as a light source, and an active light is irradiated while scanning the substrate, so that the exposure time tends to be longer than that of the conventional exposure method through a photomask. Therefore, in order to shorten the exposure time and improve production efficiency, it is necessary to further improve the sensitivity of the photosensitive resin composition.

[0006] In the stripping process, it is desired to shorten the resist stripping time in order to improve production efficiency. Therefore, a photosensitive resin composition having excellent stripping properties after curing is required. In addition, with the recent trend toward high density wiring boards, a photosensitive resin composition capable of forming a resist pattern having excellent resolution and adhesion is also required.

[0007] In response to these demands, various photosensitive resin compositions have been studied. For example, Patent Document 1 discloses a photosensitive resin composition that is excellent in sensitivity and resolution by using a specific alkali-soluble polymer and a compound having an ethylenic double bond. Patent Document 2 discloses a photosensitive resin composition that is excellent in resolution and adhesion by using a specific photopolymerizable compound. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2013-061556 A [Patent Document 2] JP 2013-195712 A Summary of the Invention [Problem to be solved by the invention]

[0009] As the wiring of semiconductor package substrates becomes finer, it is required to form resist patterns having high photosensitivity properties that enable the formation of fine wiring. In addition, from the viewpoint of improving productivity, it is desirable to shorten the stripping time of the resist pattern.

[0010] The present disclosure aims to provide a mixture of (meth)acrylate compounds capable of forming a resist pattern that has both photosensitive properties and releasability, a photosensitive resin composition containing the mixture, and a photosensitive element. [Means for solving the problem]

[0011] The present disclosure provides the following mixture of (meth)acrylate compounds, photosensitive resin composition, and photosensitive element. [1] A mixture of (meth)acrylate compounds comprising a compound represented by the following formula (1) and a compound represented by the following formula (2): [ka] [ka] [In formulas (1) and (2), R 1 and R 2 each independently represents a hydrogen atom or a methyl group; L 1 and L 2 each independently represents an alkylene group having 2 to 6 carbon atoms, m+n is 2 to 40, Y represents a methylene group or an isopropylidene group, and in formula (2), X represents a residue of a monoisocyanate compound. [2] The mixture of (meth)acrylate compounds according to the above [1], further comprising a compound represented by the following formula (3): [ka] [In formula (3), R 1 and R 2 each independently represents a hydrogen atom or a methyl group; L 1 and L 2 each independently represents an alkylene group having 2 to 6 carbon atoms, m+n is 2 to 40, and Y represents a methylene group or an isopropylidene group. [3] The mixture of (meth)acrylate compounds according to the above [2], wherein the content of the compound represented by formula (3) is 4 mass % or less. [4] A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, wherein the photopolymerizable compound comprises a mixture of the (meth)acrylate compounds according to any one of [1] to [3] above. [5] A photosensitive element comprising a support and a photosensitive layer formed on the support using the photosensitive resin composition described in [4] above. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a mixture of (meth)acrylate compounds capable of forming a resist pattern that has both photosensitive properties and releasability, a photosensitive resin composition containing the mixture, and a photosensitive element. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a photosensitive element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present disclosure will be described in detail. In this specification, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the intended effect of the step is achieved. The term "layer" includes a structure having a shape formed on the entire surface as well as a structure having a shape formed on a part of the surface when observed in a plan view. A numerical range indicated using "~" indicates a range including the numerical values ​​described before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a numerical range of a certain step may be replaced by the upper limit or lower limit of a numerical range of another step. In the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced by the values ​​shown in the examples.

[0015] In this specification, "(meth)acrylate" means at least one of "acrylate" and its corresponding "methacrylate". The same applies to other similar expressions such as "(meth)acryloyl".

[0016] In this specification, the amount of each component in the photosensitive resin composition means the total amount of the multiple substances present in the composition when the composition contains multiple substances corresponding to each component, unless otherwise specified. In this specification, the "solid content" refers to the non-volatile content of the photosensitive resin composition excluding volatile substances (water, solvent, etc.). In other words, the "solid content" refers to components other than the solvent that remain without volatilization during drying of the photosensitive resin composition described below, and also includes components that are liquid, syrup-like, or waxy at room temperature (25°C).

[0017] [Mixture of (meth)acrylate compounds] The present inventors analyzed the structure of commercially available bisphenol-type alkylene oxide-modified di(meth)acrylates and found that they contained bisphenol-type alkylene oxide-modified mono(meth)acrylates having a hydroxyl group at one end. The bisphenol-type alkylene oxide-modified mono(meth)acrylates having a hydroxyl group are considered to affect the balance between the photosensitive properties and the strippability of the resist pattern. The mixture of (meth)acrylate compounds according to this embodiment was found through an investigation into reducing the bisphenol-type alkylene oxide-modified mono(meth)acrylates having a hydroxyl group.

[0018] The mixture of (meth)acrylate compounds according to this embodiment contains a compound represented by the following formula (1) and a compound represented by the following formula (2).

[0019] [ka]

[0020] In formula (1), R 1 and R2 each independently represents a hydrogen atom or a methyl group; L 1 and L 2 each independently represents an alkylene group having 2 to 6 carbon atoms, m+n is 2 to 40, and Y represents a methylene group or an isopropylidene group.

[0021] [ka]

[0022] In formula (2), R 1 , R 2 , L 1 , L 2 , m, n, and Y are R in formula (1). 1 , R 2 , L 1 , L 2 , m, n, and Y, and X represents a residue of a monoisocyanate compound. The residue refers to the portion remaining after removing the isocyanate group from the monoisocyanate compound.

[0023] L 1 and L 2 Examples of the alkylene group having 2 to 6 carbon atoms in the formula (1) include an ethylene group, a propylene group, an isopropylene group, a butylene group, a pentylene group, and a hexylene group. Among these, from the viewpoint of improving resolution and plating resistance, an ethylene group or an isopropylene group is preferred, and an ethylene group is more preferred.

[0024] m+n may be 4 to 40, 6 to 34, 8 to 30, 8 to 28, 8 to 20, 8 to 16, or 8 to 12. When the value of m+n is 2 or more, the compatibility with the binder polymer described below is easily improved, and when the value of m+n is 40 or less, an increase in hydrophilicity is suppressed, and the developability is easily improved.

[0025] The compound represented by formula (1) can be synthesized by transesterification between an alkylene oxide-modified bisphenol compound having hydroxyl groups at both ends and a lower (meth)acrylic acid ester (e.g., methyl (meth)acrylate). However, the product obtained by the transesterification reaction contains not only the main product, the compound represented by formula (1), but also the by-product, the compound represented by formula (3): [ka]

[0026] In formula (3), R 1 , R 2 , L 1 , L 2 , m, n, and Y are R in formula (1). 1 , R 2 , L 1 , L 2 , m, n, and Y.

[0027] The compound represented by formula (1) is a bisphenol-type alkylene oxide-modified di(meth)acrylate, and the compound represented by formula (3) is a bisphenol-type alkylene oxide-modified mono(meth)acrylate having a hydroxyl group at one end.

[0028] The (meth)acrylate compound mixture according to this embodiment can be prepared using a (meth)acrylate compound containing a compound represented by formula (1) and a compound represented by formula (3), and a monoisocyanate compound.

[0029] The compound represented by formula (2) is a (meth)acrylate compound in which an organic group (a residue of a monoisocyanate compound) is introduced via a urethane bond into the compound represented by formula (3). The compound represented by formula (2) can be synthesized by reacting a monoisocyanate compound with the hydroxyl group of the compound represented by formula (3).

[0030] Examples of the monoisocyanate compound include monoisocyanates having a (meth)acryloyl group, such as (meth)acryloyloxyethyl isocyanate, (meth)acryloyloxyethoxyethyl isocyanate, and 1,1-(bis(meth)acryloyloxymethyl)ethyl isocyanate; isocyanates having an allyl group, such as allyl isocyanate, phenyl isocyanate, benzyl isocyanate, 4-methoxyphenyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, 2,4-dichlorophenyl isocyanate, 2-biphenyl isocyanate, and 1-naphthyl isocyanate. monoisocyanates having an aromatic ring, such as ethyl isocyanate, 2-phenylethyl isocyanate, 4-ethylphenyl isocyanate, and 4-butylphenyl isocyanate; monoisocyanates having an alkyl group, such as ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tert-butyl isocyanate, heptyl isocyanate, hexyl isocyanate, octyl isocyanate, dodecyl isocyanate, and octadecyl isocyanate; and monoisocyanates having an alicyclic ring, such as 1-adamantyl isocyanate, cyclohexyl isocyanate, and cyclopentyl isocyanate.

[0031] When synthesizing the compound represented by formula (2), an organotin compound is used as a catalyst. Examples of the organotin compound include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin maleate, dibutyltin bis(2-ethylhexyl mercaptoacetate), dibutyltin bis(isooctyl mercaptoacetate), and dibutyltin oxide.

[0032] The content of the compound represented by formula (2) in the mixture of (meth)acrylate compounds may be 1 mass % or more, 2 mass % or more, 3 mass % or more, or 4 mass % or more based on the total amount of the mixture from the viewpoint of improving peelability, adhesion, sensitivity, and tracking ability, and may be 30 mass % or less, 20 mass % or less, 10 mass % or less, or 5 mass % or less from the viewpoint of maintaining developability. stomach.

[0033] The mixture of (meth)acrylate compounds may contain a compound represented by formula (3). The content of the compound represented by formula (3) in the mixture of (meth)acrylate compounds is preferably 4% by mass or less, and may be 3% by mass or less, 2% by mass or less, or 1% by mass or less, from the viewpoint of improving peelability, adhesion, sensitivity, and tracking ability.

[0034] [Photosensitive resin composition] The photosensitive resin composition according to the present embodiment contains (A) a binder polymer (hereinafter sometimes referred to as "component (A)"), (B) a photopolymerizable compound (hereinafter sometimes referred to as "component (B)"), (C) a photopolymerization initiator (hereinafter sometimes referred to as "component (C)"), and (D) a sensitizer (hereinafter sometimes referred to as "component (D)"). Each component that may be contained in the photosensitive resin composition will be described in detail below.

[0035] (Component (A): Binder polymer) The photosensitive resin composition contains one or more kinds of component (A), such as acrylic resins, styrene resins, epoxy resins, amide resins, amide-epoxy resins, alkyd resins, and phenol resins.

[0036] From the viewpoint of alkaline developability, the component (A) may contain an acrylic resin. The acrylic resin is a resin having a structural unit (monomer unit) derived from a (meth)acryloyl group-containing compound.

[0037] The (meth)acryloyl group-containing compound is a compound that contains a (meth)acryloyl group.The (meth)acryloyl group-containing compound can be exemplified by hydroxyalkyl (meth)acrylate, (meth)acrylic acid, (meth)acrylic acid alkyl ester, (meth)acrylic acid aryl ester, (meth)acrylic acid cycloalkyl ester, acrylamide such as diacetone acrylamide, (meth)acrylic acid tetrahydrofurfuryl ester, (meth)acrylic acid dimethylaminoethyl ester, (meth)acrylic acid diethylaminoethyl ester, (meth)acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, α-bromoacrylic acid, α-chloroacrylic acid, β-furyl (meth)acrylic acid, and β-styryl (meth)acrylic acid.

[0038] The acrylic resin may be, for example, a polymer (a) having at least one unit selected from the group consisting of (meth)acrylic acid units, (meth)acrylic acid alkyl ester units, (meth)acrylic acid aryl ester units, and hydroxyalkyl (meth)acrylate units.

[0039] The (meth)acrylic acid unit is a structural unit derived from (meth)acrylic acid. When the polymer (a) has a (meth)acrylic acid unit, the content of the (meth)acrylic acid unit may be 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more, based on the total amount of the monomer units constituting the polymer (a), from the viewpoint of resolution and adhesion, and may be 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less.

[0040] The (meth)acrylic acid alkyl ester unit is a structural unit derived from a (meth)acrylic acid alkyl ester. The alkyl group of the (meth)acrylic acid alkyl ester may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a undecyl group, a dodecyl group, or a structural isomer thereof, and may be an alkyl group having 1 to 4 carbon atoms from the viewpoint of releasability.

[0041] When the polymer (a) has a (meth)acrylic acid alkyl ester unit, the content of the (meth)acrylic acid alkyl ester unit, based on the total amount of monomer units constituting the polymer (a), may be 1 mass % or more, 2 mass % or more, or 3 mass % or more from the viewpoint of releasability, and may be 30 mass % or less, 20 mass % or less, or 10 mass % or less from the viewpoint of resolution and adhesion.

[0042] The (meth)acrylic acid aryl ester unit is a structural unit derived from a (meth)acrylic acid aryl ester. Examples of the (meth)acrylic acid aryl ester include benzyl (meth)acrylate, phenyl (meth)acrylate, and naphthyl (meth)acrylate. When the polymer (a) has a (meth)acrylic acid aryl ester unit, the content of the (meth)acrylic acid aryl ester unit may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, and may be 40% by mass or less, 35% by mass or less, 30% by mass or less, or 25% by mass or less, based on the total amount of the monomer units constituting the polymer (a), from the viewpoint of resolution and adhesion.

[0043] The hydroxyalkyl (meth)acrylate unit is a structural unit derived from hydroxyalkyl (meth)acrylate. Examples of the hydroxyalkyl (meth)acrylate include hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and hydroxyhexyl (meth)acrylate. In the hydroxyalkyl (meth)acrylate unit, when the number of carbon atoms of the alkyl part is 3 or more, it may have a branched structure.

[0044] When the polymer (a) has a hydroxyalkyl (meth)acrylate unit, the content of the hydroxyalkyl (meth)acrylate unit may be 0.5 mass% or more, 0.75 mass% or more, or 1.0 mass% or more based on the total amount of monomer units constituting the polymer (a) from the viewpoint of dispersibility, and may be 20 mass% or less, 15 mass% or less, or 8 mass% or less from the viewpoint of water absorbency.

[0045] In order to further improve the resolution and adhesion of the photosensitive resin composition, the polymer (a) may have a structural unit derived from styrene or a styrene derivative (hereinafter also referred to as a "styrene-based unit"). Examples of the styrene derivative include vinyltoluene, α-methylstyrene, p-methylstyrene, and p-ethylstyrene.

[0046] When polymer (a) has a styrene-based unit, the content of the styrene-based unit, based on the total amount of monomer units constituting polymer (a), may be 35% by mass or more, 40% by mass or more, or 45% by mass or more from the viewpoint of resolution, and may be 70% by mass or less, 60% by mass or less, or 50% by mass or less from the viewpoint of developability.

[0047] The polymer (a) may further have a structural unit derived from a monomer other than those mentioned above. Examples of the other monomer include acrylonitrile, vinyl alcohol ethers such as vinyl-n-butyl ether, maleic acid, maleic anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid.

[0048] The component (A) may contain a binder polymer other than the polymer (a), or may consist of only the polymer (a). From the viewpoints of adhesion and resolution, the content of the polymer (a) in the component (A) may be 50 to 100 mass % or 80 to 100 mass % based on the total amount of the component (A).

[0049] The acid value of the polymer (a) may be 100 mgKOH / g or more, 120 mgKOH / g or more, 140 mgKOH / g or more, or 150 mgKOH / g or more from the viewpoint of developability, and may be 250 mgKOH / g or less, 240 mgKOH / g or less, or 230 mgKOH / g or less from the viewpoint of adhesion (resistance to developing solution) of the cured product of the photosensitive resin composition. The acid value of the polymer (a) can be adjusted by the content of the structural unit (e.g., (meth)acrylic acid unit) constituting the polymer (a). When the (A) component contains a binder polymer other than the polymer (a), the acid value of the other binder polymer may also be within the above range.

[0050] The weight average molecular weight (Mw) of the polymer (a) may be 10000 or more, 20000 or more, 25000 or more, 30000 or more, 35000 or more, or 40000 or more from the viewpoint of adhesion (resistance to developing solution) of the cured product of the photosensitive resin composition and ease of forming a thick resist pattern, and may be 100000 or less, 80000 or less, 60000 or less, or 50000 or less from the viewpoint of developability. The dispersity (Mw / Mn) of the polymer (a) may be, for example, 1.0 or more or 1.5 or more, and may be 3.0 or less or 2.5 or less from the viewpoint of adhesion and resolution. When the (A) component contains a binder polymer other than the polymer (a), the Mw of the other binder polymer may also be within the above range.

[0051] The weight average molecular weight and the degree of dispersion can be measured, for example, by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene. More specifically, they can be measured under the conditions described in the Examples. In addition, for compounds with low molecular weights, when it is difficult to measure the weight average molecular weight using the above-mentioned method, the molecular weight can be measured by another method and the average can be calculated.

[0052] The content of the component (A), based on the total solid content of the photosensitive resin composition, may be 20 mass % or more, 30 mass % or more, or 40 mass % or more from the viewpoint of film formability, and may be 90 mass % or less, 80 mass % or less, 70 mass % or less, or 65 mass % or less from the viewpoint of sensitivity and resolution.

[0053] The content of the (A) component, relative to 100 parts by mass of the total amount of the (A) component and the (B) component, may be 30 parts by mass or more, 40 parts by mass or more, or 50 parts by mass or more from the viewpoint of film formability, and may be 70 parts by mass or less, 65 parts by mass or less, or 60 parts by mass or less from the viewpoint of sensitivity and resolution.

[0054] ((B) component: photopolymerizable compound) The component (B) contains a mixture of (meth)acrylate compounds according to the present embodiment. When the photosensitive resin composition contains a photopolymerizable compound having a specific structure, a resist pattern having excellent photosensitivity and peelability can be formed.

[0055] The component (B) may contain a photopolymerizable compound other than the above-mentioned (meth)acrylate compound. Examples of the other photopolymerizable compound include nonylphenoxypolyethyleneoxyacrylate, a phthalic acid compound, a (meth)acrylic acid alkyl ester, and a photopolymerizable compound having at least one cationic polymerizable cyclic ether group in the molecule (such as an oxetane compound).

[0056] The content of the (B) component, based on the total solid content of the photosensitive resin composition, may be 3 mass % or more, 10 mass % or more, or 25 mass % or more from the viewpoints of sensitivity and resolution, and may be 70 mass % or less, 60 mass % or less, or 50 mass % or less from the viewpoint of film formability.

[0057] (Component (C): Photopolymerization initiator) The photosensitive resin composition contains one or more kinds of component (C). Component (C) is not particularly limited as long as it is a component that can polymerize component (B), and can be appropriately selected from commonly used photopolymerization initiators.

[0058] Examples of the component (C) include hexaarylbiimidazole compounds; aromatic ketone compounds such as benzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1; alkyl aryl ketones such as aryl aryl ketones; benzoin ether compounds such as benzoin alkyl ether; benzoin compounds such as benzoin and alkylbenzoin; benzyl derivatives such as benzyl dimethyl ketal; and phosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide.

[0059] The component (C) may contain a hexaarylbiimidazole compound from the viewpoint of improving the adhesion of the photosensitive layer to a smooth substrate. The aryl group in the hexaarylbiimidazole compound may be a phenyl group or the like. The hydrogen atom bonded to the aryl group in the hexaarylbiimidazole compound may be substituted with a halogen atom (such as a chlorine atom).

[0060] The hexaarylbiimidazole compound may be a 2,4,5-triarylimidazole dimer, such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl)imidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer.

[0061] The content of component (C) may be 1.0 to 10 parts by mass, 2.0 to 8 parts by mass, 3.0 to 7.0 parts by mass, or 4.0 to 6.0 parts by mass, relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (C) is within this range, it becomes easy to improve both photosensitivity and resolution in a well-balanced manner.

[0062] (Component (D): Sensitizer) The photosensitive resin composition contains one or more kinds of component (D). By containing component (D), the photosensitive resin composition according to the present embodiment can effectively utilize the absorption wavelength of the actinic ray used for exposure.

[0063] Examples of the (D) component 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. From the viewpoint of further improving resolution and adhesion, the (D) component may contain a pyrazoline compound or a dialkylaminobenzophenone compound.

[0064] Examples of pyrazoline compounds include 1-(4-methoxyphenyl)-3-styryl-5-phenyl-pyrazoline, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1,5-bis-(4-methoxyphenyl)-3-(4-methoxystyryl)-pyrazoline, 1-(4-isopropylphenyl)-3-styryl-5-phenyl-pyrazoline, 1-phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 1,5-bis-(4-isopropylphenyl)-3-(4- isopropylstyryl)-pyrazoline, 1-(4-methoxyphenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(4-isopropyl-styryl)-5-(4-isopropyl 1-(4-methoxyphenyl)-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,6-dimethoxystyryl)-5 -(2,6-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,4-dimethoxystyryl)-5-(2 ,4-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,5-dimethoxystyryl)-5 -(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(3,4-dimethoxystyryl)-5- (3,4-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, and 1-(4-isopropyl-phenyl)-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline.

[0065] Examples of dialkylaminobenzophenone compounds include 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, and 4-benzoyl-4'-methyldiphenyl sulfide.

[0066] From the viewpoint of further improving adhesion, the content of the (D) component may be 1.60 parts by mass or less, 1.50 parts by mass or less, 1.40 parts by mass or less, or 1.35 parts by mass or less, relative to 100 parts by mass of the (C) component. From the viewpoint of improving developability, adhesion, and releasability in a well-balanced manner, the content of the (D) component may be 0.15 to 1.60 parts by mass, 0.20 to 1.50 parts by mass, 0.25 to 1.40 parts by mass, or 0.30 to 1.35 parts by mass, relative to 100 parts by mass of the (C) component.

[0067] From the viewpoint of improving photosensitivity and resolution, the content of the component (D) may be 0.01 to 0.10 parts by mass, 0.01 to 0.09 parts by mass, or 0.01 to 0.08 parts by mass relative to 100 parts by mass of the total amount of the components (A) and (B).

[0068] (Component (E): Polymerization inhibitor) The photosensitive resin composition may further contain a polymerization inhibitor as component (E) from the viewpoint of suppressing polymerization in unexposed areas during resist pattern formation and further improving resolution. Examples of the polymerization inhibitor include 4-tert-butylcatechol and 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl.

[0069] The content of the component (E) may be 0.001 to 0.10 parts by mass, 0.005 to 0.08 parts by mass, or 0.01 to 0.06 parts by mass relative to 100 parts by mass of the total amount of the components (A) and (B).

[0070] (Other Ingredients) The photosensitive resin composition may further contain one or more other components other than the above-mentioned components. Examples of the other components include hydrogen donors (bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, leuco crystal violet, N-phenylglycine, etc.), dyes (malachite green, etc.), tribromophenyl sulfone, photocoloring agents, thermal coloring inhibitors, plasticizers (p-toluenesulfonamide, etc.), pigments, fillers, defoamers, flame retardants, stabilizers, adhesion agents, leveling agents, peeling promoters, antioxidants, fragrances, imaging agents, and thermal crosslinking agents. The content of the other components may be 0.005 parts by mass or more or 0.01 parts by mass or more, or 20 parts by mass or less, relative to 100 parts by mass of the total amount of the (A) component and the (B) component.

[0071] The photosensitive resin composition may contain an organic solvent in order to improve the handling property of the photosensitive composition and adjust the viscosity and storage stability. As the organic solvent, any commonly used organic solvent may be used without any particular limitation. Examples of the organic solvent include methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, and mixed solvents thereof. For example, the components (A) to (D) may be dissolved in an organic solvent to prepare a solution having a solid content of about 30 to 60 mass% (hereinafter referred to as a "coating liquid"). The solid content means the remaining components obtained by removing volatile components from the solution of the photosensitive resin composition.

[0072] The photosensitive resin composition can be suitably used for forming a resist pattern, and can be particularly suitably used in the method for producing a wiring board described below.

[0073] [Photosensitive element] The photosensitive element of the present embodiment includes a support and a photosensitive layer formed on the support, and the photosensitive layer contains the above-mentioned photosensitive resin composition. When using the photosensitive element of the present embodiment, the photosensitive layer may be laminated on a substrate and then exposed to light without peeling off the support (support film).

[0074] Fig. 1 is a schematic cross-sectional view of a photosensitive element according to one embodiment. As shown in Fig. 1, the photosensitive element 1 includes a support 2, a photosensitive layer 3 formed on the support 2 and derived from the above-mentioned photosensitive resin composition, and further includes other layers such as a protective layer 4 that are provided as necessary.

[0075] The support 2 and the protective layer 4 may each be a polymer film having heat resistance and solvent resistance, for example, a polyester film such as a polyethylene terephthalate film, a polyethylene film, a polyolefin film such as a polypropylene film, etc. The support 2 and the protective layer 4 may each be a film of a hydrocarbon polymer other than polyolefin. The film of a hydrocarbon polymer including polyolefin may have a low density, for example, 1.014 g / cm 3 The support 2 and the protective layer 4 may each be a stretched film obtained by stretching the low-density hydrocarbon-based polymer film. The type of the polymer film constituting the protective layer 4 may be the same as or different from the type of the polymer film constituting the support 2.

[0076] These polymer films can be purchased, for example, as polyethylene terephthalate films such as the PS series (e.g., PS-25) manufactured by Teijin Limited, polyethylene films such as NF-15 manufactured by Tamapoly Co., Ltd., or polypropylene films manufactured by Oji Paper Co., Ltd. (e.g., Alphan MA-410, E-200C) and Shin-Etsu Film Co., Ltd.

[0077] The thickness of the support 2 may be 1 μm or more or 5 μm or more from the viewpoint of suppressing damage to the support 2 when the support 2 is peeled off from the photosensitive layer 3, and may be 100 μm or less, 50 μm or less, or 30 μm or less from the viewpoint of enabling suitable exposure even when exposure is performed through the support 2.

[0078] The thickness of the protective layer 4 may be 1 μm or more, 5 μm or more, or 15 μm or more from the viewpoint of suppressing damage to the protective layer 4 when the photosensitive layer 3 and the support 2 are laminated onto the substrate while peeling off the protective layer 4, and may be 100 μm or less, 50 μm or less, or 30 μm or less from the viewpoint of improving productivity.

[0079] The photosensitive layer 3 is made of the above-mentioned photosensitive resin composition. The thickness of the photosensitive layer 3 after drying (after volatilization of the organic solvent in the case where the photosensitive resin composition contains an organic solvent) may be 1 μm or more or 5 μm or more from the viewpoint of facilitating coating and improving productivity, and may be 100 μm or less, 50 μm or less, or 40 μm or less from the viewpoint of further improving adhesion and resolution.

[0080] The photosensitive element 1 can be obtained, for example, as follows. First, a photosensitive layer 3 is formed on a support 2. The photosensitive layer 3 can be formed, for example, by applying a photosensitive resin composition containing an organic solvent to form a coating layer, and drying the coating layer. Next, a protective layer 4 is formed on the surface of the photosensitive layer 3 opposite the support 2.

[0081] The coating layer is formed by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, bar coating, etc. The coating layer is dried so that the amount of the organic solvent remaining in the photosensitive layer 3 becomes, for example, 2 mass % or less, specifically, for example, at 70 to 150° C. for about 5 to 30 minutes.

[0082] The photosensitive element may further include an intermediate layer between the support 2 and the photosensitive layer 3. The intermediate layer may be a layer containing a water-soluble resin. Examples of the water-soluble resin include a resin containing polyvinyl alcohol as a main component.

[0083] In another embodiment, the photosensitive element does not need to include a protective layer, and may further include other layers, such as a cushion layer, an adhesive layer, a light absorbing layer, and a gas barrier layer.

[0084] The photosensitive element 1 may be, for example, in the form of a sheet, or may be in the form of a photosensitive element roll wound around a core. In the photosensitive element roll, the photosensitive element 1 is preferably wound so that the support 2 is on the outside. The core is formed of, for example, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, or the like. An end separator may be provided on the end surface of the photosensitive element roll from the viewpoint of end surface protection, and a moisture-proof end surface separator may be provided from the viewpoint of edge fusion resistance. The photosensitive element 1 may be, for example, wrapped in a black sheet with low moisture permeability.

[0085] The photosensitive element 1 can be suitably used for forming a resist pattern, and can be particularly suitably used in a method for producing a wiring board, which will be described later.

[0086] [Method of forming resist pattern] The method for forming a resist pattern of this embodiment includes a step of forming a photosensitive layer on a substrate using the photosensitive resin composition or the photosensitive element (photosensitive layer forming step), a step of irradiating at least a part (predetermined part) of the photosensitive layer with active light to form a photocured part (exposure step), and a step of removing at least a part of the uncured part from the substrate (development step), and may include other steps as necessary. The resist pattern may be a photocured product pattern of the photosensitive resin composition or a relief pattern. The method for forming a resist pattern may be a method for manufacturing a substrate with a resist pattern.

[0087] (Photosensitive layer formation process) The method of forming the photosensitive layer on the substrate may be, for example, coating and drying the photosensitive resin composition, or removing the protective layer from the photosensitive element, and then pressing the photosensitive layer of the photosensitive element onto the substrate while heating. When the photosensitive element is used, a laminate consisting of a substrate, a photosensitive layer, and a support, which are laminated in order, is obtained. The substrate is not particularly limited, but is usually a circuit-forming substrate having an insulating layer and a conductor layer formed on the insulating layer, or a die pad (substrate for lead frame) such as an alloy substrate.

[0088] The surface roughness (Ra) of the substrate may be 200 nm or less, 180 nm or less, or 160 nm or less from the viewpoint of suppressing halation due to unevenness of the substrate and improving resolution, and may be 10 nm or more, 30 nm or more, or 40 nm or more from the viewpoint of improving adhesion of the resist pattern. Ra may be 10 to 200 nm, 30 to 180 nm, or 40 to 160 nm from the viewpoint of maintaining a balance between resolution and adhesion.

[0089] When a photosensitive element is used, the photosensitive layer forming step is preferably carried out under reduced pressure from the viewpoints of adhesion and followability. The photosensitive layer and / or the substrate may be heated at a temperature of 70 to 130° C. during pressure bonding. The pressure bonding is carried out at a pressure of about 0.1 to 1.0 MPa (1 to 10 kgf / cm 2The pressure may be about 100 MPa (about 100 MPa), but these conditions are appropriately selected according to need. If the photosensitive layer is heated to 70 to 130° C., it is not necessary to preheat the substrate in advance, but the substrate can be preheated in order to further improve the adhesion and conformability.

[0090] (Exposure process) In the exposure step, at least a part of the photosensitive layer formed on the substrate is irradiated with active light rays, whereby the part irradiated with the active light rays is photocured to form a latent image. In this case, if a support is present on the photosensitive layer, and if the support is transparent to the active light rays, the active light rays can be irradiated through the support, but if the support is light-shielding, the support is removed before the photosensitive layer is irradiated with the active light rays.

[0091] The exposure method may be a method of irradiating an active light beam imagewise through a negative or positive mask pattern called artwork (mask exposure method). Alternatively, a method of irradiating an active light beam imagewise by a projection exposure method may be used. Alternatively, a method of irradiating an active light beam imagewise by a direct writing exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method may be used.

[0092] As the light source of the actinic rays, a known light source can be used, for example, a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser, a solid-state laser such as a YAG laser, a semiconductor laser, etc., which effectively radiate ultraviolet rays and visible light, can be used.

[0093] (Development process) In the development process, at least a part of the uncured portion (other than the photocured portion) of the photosensitive layer is removed from the substrate, thereby forming a resist pattern on the substrate. If a support is present on the photosensitive layer, the support is removed, and then the area other than the photocured portion (also called the unexposed portion) is removed (developed). There are two development methods, wet development and dry development, and wet development is widely used.

[0094] In the case of wet development, a developer corresponding to the photosensitive resin composition is used to develop the photosensitive resin composition by a known developing method. Examples of the developing method include a dip method, a paddle method, a spray method, a brushing method, a scrubbing method, and a swinging immersion method. From the viewpoint of improving the resolution, a high-pressure spray method may be used as the developing method. Two or more of these methods may be combined to perform the development.

[0095] The composition of the developer is appropriately selected depending on the composition of the photosensitive resin composition. Examples of the developer include an alkaline aqueous solution and an organic solvent developer.

[0096] From the viewpoint of safety, stability, and good operability, an alkaline aqueous solution may be used as the developer. Examples of the base of the alkaline aqueous solution 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; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2, and morpholine.

[0097] The alkaline aqueous solution used for development may be a dilute solution of 0.1 to 5% by mass sodium carbonate, a dilute solution of 0.1 to 5% by mass potassium carbonate, a dilute solution of 0.1 to 5% by mass sodium hydroxide, or a dilute solution of 0.1 to 5% by mass sodium tetraborate. The pH of the alkaline aqueous solution may be in the range of 9 to 11, and the temperature can be adjusted according to the alkaline developability of the photosensitive layer. For example, a surfactant, an antifoaming agent, or a small amount of an organic solvent for promoting development may be mixed into the alkaline aqueous solution.

[0098] Examples of organic solvents used in the alkaline aqueous solution include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0099] Examples of organic solvents used in the organic solvent developer include 1,1,1-trichloroethane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. To prevent ignition, water may be added to these organic solvents in an amount of 1 to 20% by mass to prepare the organic solvent developer.

[0100] In the method for forming a resist pattern in this embodiment, after removing the uncured portion in the development step, heating at about 60 to 250° C. or applying 0.2 to 10 J / cm 2 is performed as necessary. 2 The method may further include a step of hardening the resist pattern by performing exposure to light of about 100 nm.

[0101] [Method of manufacturing wiring board] The method for manufacturing a wiring board according to this embodiment includes a step of forming a conductor pattern by etching or plating a substrate on which a resist pattern has been formed using the above-described resist pattern forming method, and may also include other steps, such as a resist pattern removal step, as necessary.

[0102] In the etching process, the conductive layer provided on the substrate is etched away using a resist pattern formed on the substrate as a mask to form a conductive pattern. The etching method is appropriately selected depending on the conductive layer to be removed. Examples of the etching solution include a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, and a hydrogen peroxide-based etching solution.

[0103] In the plating process, the conductive layer provided on the substrate is plated using a resist pattern formed on the substrate as a mask. After the plating process, the resist may be removed by removing the resist pattern as described below, and the conductive layer covered by the resist may be etched to form a conductive pattern. The plating process may be performed by electrolytic plating or electroless plating, or may be performed by electroless plating.

[0104] After the etching or plating process, the resist pattern on the substrate is removed. The resist pattern can be removed, for example, by using an inorganic alkaline stripping solution or an organic alkaline stripping solution. As the inorganic alkaline stripping solution, for example, a 1 to 10 mass% aqueous solution of sodium hydroxide and a 1 to 10 mass% aqueous solution of potassium hydroxide are used. As the organic alkaline stripping solution, for example, an amine-based stripping solution such as ethanolamine, ethylenediamine, diethylenetriamine, etc., and an aqueous solution of tetramethylammonium hydroxide are used.

[0105] When the resist pattern is removed after the plating process, the conductor layer covered with the resist is etched by an etching process to form a conductor pattern, thereby manufacturing a desired wiring board. The method of the etching process is appropriately selected depending on the conductor layer to be removed. For example, the above-mentioned etching solution can be used.

[0106] The method for manufacturing a wiring board according to this embodiment is applicable to the manufacture of not only single-layer wiring boards but also multi-layer wiring boards, and also applicable to the manufacture of wiring boards having small diameter through holes. EXAMPLES

[0107] The present disclosure will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0108] [Mixture of (meth)acrylate compounds] (Reference example) 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane (wherein R 1 and R 2 : Methyl group, L 1 and L 2 As a commercially available (meth)acrylate compound containing m: ethylene group, Y: isopropylidene group, and m+n: 10 (average value), a product name "FA-321M" manufactured by Resonac Corporation was prepared.

[0109] Example 1 201 g of FA-321M was added to a flask equipped with a stirrer and a thermometer, and 0.04 g of a 10% by mass solution of dibutyltin dilaurate in ethyl acetate was added dropwise to the flask while stirring at 80° C. under a nitrogen atmosphere. Next, 3 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the flask, and the mixture was stirred at 80° C. for 30 minutes to obtain Product B-1.

[0110] Example 2 200 g of FA-321M was added to a flask equipped with a stirrer and a thermometer, and 0.04 g of a 10% by mass solution of dibutyltin dilaurate in ethyl acetate was added dropwise to the flask while stirring at 80° C. under a nitrogen atmosphere. Next, 3 g of 2-methacryloyloxyethyl isocyanate (manufactured by Resonac Corporation, product name "Karends MOI") was added dropwise to the flask, and the mixture was stirred at 80° C. for 30 minutes to obtain Product B-2.

[0111] Example 3 202 g of FA-321M was added to a flask equipped with a stirrer and a thermometer, and 0.04 g of a 10% by mass solution of dibutyltin dilaurate in ethyl acetate was added dropwise to the flask while stirring at 80° C. under a nitrogen atmosphere. Next, 3 g of hexyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the flask, and the mixture was stirred at 80° C. for 30 minutes to obtain Product B-3.

[0112] [analysis] In order to calculate the ratio (%) of the compounds represented by formulas (1), (2) and (3) contained in FA-321M and the product, measurements were performed using reverse phase liquid chromatography (RPLC) and MALDI-TOF MS.

[0113] (RPLC) The measurement device used was Shimadzu Corporation's "NexeraXR LC20ADXR" and the column used was BEH C18 (2.1 mm ID x 100 mm, 1.8 μum). Measurement was performed with the linear gradient shown in Table 1 using acetonitrile as eluent A and distilled water as eluent B. The measurement sample was adjusted to a solution with a concentration of 1 mg / mL using acetonitrile, and the injection volume was 1.0 μL.

[0114] [Table 1]

[0115] (MALDI-TOF MS) As a measurement sample, the product, DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile), and sodium trifluoroacetate were adjusted to a concentration of 10 mg / mL with THF (tetrahydrofuran), and a 1:10:1 mixture was prepared. Next, 0.7 μL of the mixture was dropped onto a measurement plate, air-dried until THF was completely evaporated, and the plate was placed in an analyzer and measured. The measurement was performed using a Bruker "AutoFlex" measurement device with a laser wavelength of 337 nm (N2 laser), accelerating voltage of 20 kV, matrix of (DCTB), and laser output of 30%.

[0116] The proportions (%) of the compounds represented by formulae (1), (2) and (3) contained in FA-321M and the product, as calculated by RPLC and MALDI-TOF MS, are shown in Table 2.

[0117] [Table 2]

[0118] [Photosensitive resin composition] Each photosensitive resin composition was prepared by mixing the components shown in Table 3 in the amounts (parts by mass) shown in the table. The amounts (parts by mass) of components other than the solvent shown in Table 3 are the masses of non-volatile matters (solid contents). Details of each component shown in Table 3 are as follows.

[0119] (Component (A)) A-1: Ethylene glycol monomethyl ether / toluene solution (solid content: 47% by mass) of a copolymer of methacrylic acid / methyl methacrylate / styrene / benzyl methacrylate (mass ratio: 27 / 5 / 45 / 23, Mw: 47000, acid value: 176.1 mgKOH / g, Tg: 107°C) ((B) Photopolymerizable compound) B-1: Product B-1 of Example 1 B-2: Product B-2 of Example 2 B-3: Product B-3 of Example 3 B-4: Reference example FA-321M ((C) Photopolymerization initiator) B-CIM: 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (manufactured by Hodogaya Chemical Co., Ltd.) ((D) Sensitizer) PZ-501D: 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline (manufactured by Nippon Chemical Industry Co., Ltd.) ((E) Polymerization inhibitor) Q-TBC-5P: 4-tert-butylcatechol (DIC Corporation) LA-7RD: 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (ADEKA Corporation) (Adhesion promoter) SF-808H: A mixture of carboxybenzotriazole, 5-amino-1H-tetrazole and methoxypropanol (manufactured by Sanwa Chemical Co., Ltd.) (Photochromic agent) LCV: Leuco Crystal Violet (Yamada Chemical Industry Co., Ltd.) (dye) AKG: Malachite Green (Osaka Organic Chemical Industry Ltd.)

[0120] [Photosensitive element] A polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name "FS-31") having a thickness of 16 μm was prepared as a support. The photosensitive resin composition was applied onto the support and then dried for 10 minutes in a hot air convection dryer at 90° C. to form a photosensitive layer having a thickness of 25 μm after drying. Subsequently, a polyethylene film (manufactured by Tamapoly Corporation, product name "NF-15A") was laminated as a protective layer on the photosensitive layer to obtain a photosensitive element in which the support, photosensitive layer, and protective layer were laminated in this order.

[0121] [Laminate] A copper-clad laminate (manufactured by Resonac Corporation, product name "MCL-E-679"), which is a glass epoxy material with copper foil (thickness: 35 μm) laminated on both sides, was washed with water, pickled, and washed with water, and then dried with an air flow. The surface-treated copper-clad laminate was heated to 80°C, and a photosensitive element was laminated so that the photosensitive layer was in contact with the copper surface while peeling off the protective layer. Lamination was performed using a heat roll at 110°C at a pressure of 0.4 MPa and a roll speed of 1.0 m / min, so that the photosensitive layer of the photosensitive element was in contact with the copper surface of the copper substrate while peeling off the protective layer. As a result, a laminate in which the substrate, photosensitive layer, and support were laminated in this order was obtained.

[0122] [evaluation] The obtained laminate was subjected to the following evaluations, and the evaluation results are shown in Table 3.

[0123] (sensitivity) After placing a 41-step tablet (manufactured by Resonac Co., Ltd.) on the support of the laminate, the photosensitive layer was exposed through the support using a projection exposure device (manufactured by Ushio Inc., product name "UX-2240SM") with an ultra-high pressure mercury lamp (365 nm) as the light source, with an exposure amount (amount of irradiation energy) that would result in 11 remaining steps after development of the 41-step tablet. The exposure amount at this time (unit: mJ / cm 2 The sensitivity was evaluated by the following formula: The lower the exposure amount, the better the sensitivity.

[0124] (minimum development time) The laminate was cut into a square (5 cm x 5 cm), and the support was peeled off to obtain a test piece. The support was peeled off from the test piece to expose the photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30°C was sprayed on it. The time until the photosensitive layer was completely removed was measured and taken as the minimum development time. The shorter the minimum development time (unit: seconds), the better the developability.

[0125] (Resolution) Using a drawing pattern with a line width (L) / space width (S) of 3x / x (x = 3 to 30, unit: μm, 1 μm intervals), the photosensitive layer of the laminate was exposed using a projection exposure system (UX-2240SM) with an exposure amount that resulted in 11 steps remaining on a Hitachi 41-step step tablet.

[0126] After exposure, the support was peeled off from the laminate to expose the photosensitive layer, and the unexposed areas were removed by spraying a 1% by mass aqueous solution of sodium carbonate at 30°C for twice the minimum development time. After development, the space areas (unexposed areas) were removed without residue, and the line areas (exposed areas) were formed without wobbling or chipping, and the resolution was evaluated based on the minimum space width (unit: μm). The smaller the resolution value, the better the resolution.

[0127] (peelability) A glass chrome type phototool (having a 50mm x 40mm flat pattern) was used as a negative for peel test evaluation on the support of the test piece, and the photosensitive layer was exposed with the above-mentioned specified energy amount using a projection exposure device (UX-2240SM). After exposure, the support was peeled off to expose the photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30°C was sprayed for twice the minimum development time to remove the unexposed parts.

[0128] After the development process, the substrate was immersed in an amine-based stripping solution (aqueous solution of 15% by volume R-100S + 8% by volume R-101, manufactured by Mitsubishi Gas Chemical Co., Ltd.) heated to 50°C. The time until the photosensitive layer was completely removed was measured and taken as the stripping time. A shorter stripping time means better strippability.

[0129] (Flexibility) While peeling off the protective layer from the photosensitive element, the photosensitive layer and the support were laminated on a slide glass to prepare a laminate for measuring flexibility. The lamination was performed with the photosensitive layer of the photosensitive element in contact with the surface of the slide glass, using a roll at 25°C, with a pressure of 0.4 MPa and a roll speed of 1.0 m / min. The maximum indentation depth of the prepared laminate from the support side was measured using a hardness tester (Fischer Instruments, Inc., FISCHERSCOPE H100SMC). The indenter was a spherical indenter of φ0.4 mm, and the maximum indentation depth was measured when a load of 300 mN / 10 seconds was applied and the load was held for 5 seconds, and this was taken as the indentation value. The larger the indentation value, the better the flexibility.

[0130] [Table 3] [Explanation of symbols]

[0131] 1...photosensitive element, 2...support, 3...photosensitive layer, 4...protective layer.

Claims

1. A mixture of (meth)acrylate compounds containing a compound represented by the following formula (1) and a compound represented by the following formula (2): 【Chemistry 1】 【Chemistry 2】 [In formulas (1) and (2), R １ and R ２ each independently represents a hydrogen atom or a methyl group; L １ and L ２ each independently represents an alkylene group having 2 to 6 carbon atoms, m+n is 2 to 40, Y represents a methylene group or an isopropylidene group, and in formula (2), X represents a residue of a monoisocyanate compound.

2. The mixture of (meth)acrylate compounds according to claim 1 , further comprising a compound represented by the following formula (3): 【Chemistry 3】 [In formula (3), R １ and R ２ each independently represents a hydrogen atom or a methyl group; L １ and L ２ each independently represents an alkylene group having 2 to 6 carbon atoms, m+n is 2 to 40, and Y represents a methylene group or an isopropylidene group.

3. The mixture of (meth)acrylate compounds according to claim 2 , wherein the content of the compound represented by formula (3) is 4 mass % or less.

4. A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, A photosensitive resin composition, wherein the photopolymerizable compound comprises the mixture of (meth)acrylate compounds according to any one of claims 1 to 3.

5. A photosensitive element comprising a support and a photosensitive layer formed on the support using the photosensitive resin composition according to claim 4.

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