Photosensitive element and method for manufacturing laminate

Abstract

Provided is a photosensitive element comprising a support, and a photosensitive layer located on the support. The absorbance of a 365 nm wavelength light in the photosensitive layer is 0.0160 or less per 1 µm of the thickness of the photosensitive layer.

Description

Photosensitive element and method for manufacturing laminate

[0001] FIELD OF THE DISCLOSURE This disclosure relates to methods for making photosensitive elements and laminates.

[0002] In the field of printed wiring board manufacturing, laminated film-like photosensitive elements are widely used as resist materials for processes such as etching and plating. Photosensitive elements generally include a support and a photosensitive layer on the support, and the photosensitive layer is formed from a photosensitive resin composition containing a photopolymerizable compound, a polymerization initiator, and the like.

[0003] The photosensitive resin composition that forms the photosensitive layer is appropriately designed depending on the line width, film thickness, exposure wavelength, desired physical properties of the resist pattern, etc. Patent Document 1 describes that when a photosensitive resin composition that includes a binder polymer, a photopolymerizable compound containing a compound having a ditrimethylolpropane skeleton, a photopolymerization initiator, and a hydrogen donor is exposed with a 405 nm blue-violet laser diode, the peeling time of the cured product is shortened.

[0004] International Publication No. 2022 / 202485

[0005] An object of the present disclosure is to provide a photosensitive element capable of forming a resist pattern with excellent rectangularity, and a method for producing a laminate using the same.

[0006] The present disclosure includes the following embodiments. The present disclosure is not limited to the following embodiments. One embodiment relates to a photosensitive element comprising a support and a photosensitive layer located on the support, wherein the photosensitive layer has an absorbance of 0.0160 or less at 365 nm wavelength light per 1 μm of photosensitive layer thickness.

[0007] Another embodiment relates to a method for producing a laminate, comprising: disposing a photosensitive layer of the photosensitive element on a substrate; photocuring a portion of the photosensitive layer; and removing an uncured portion of the photosensitive layer to form a resist pattern.

[0008] The present disclosure can provide a photosensitive element capable of forming a resist pattern with excellent rectangularity, and a method for producing a laminate using the same.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0010] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limit of a numerical range described in the present disclosure may be replaced with a value shown in an example.

[0011] In the present disclosure, the photosensitive resin composition may contain one or more substances corresponding to each component, unless otherwise specified.

[0012] In the present disclosure, when a photosensitive resin composition contains multiple substances corresponding to a certain component, the content of the component in the photosensitive resin composition means the total amount of the multiple substances present in the photosensitive resin composition, unless otherwise specified.

[0013] In the present disclosure, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid, (meth)acrylate refers to at least one of acrylate and its corresponding methacrylate, and (meth)acryloyl group refers to at least one of acryloyl group and methacryloyl group.

[0014] 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 shown below.

[0015] Pump: Hitachi L-6000 type (trade name, manufactured by Hitachi, Ltd.) Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (all manufactured by Resonaq Technoservice Co., Ltd., trade names) Eluent: tetrahydrofuran Measurement temperature: 40°C Flow rate: 2.05 mL / min Detector: L-3300 type RI (trade name, manufactured by Hitachi, Ltd.)

[0016] The photosensitive element of one embodiment of the present disclosure includes a support and a photosensitive layer located on the support, wherein the photosensitive layer has an absorbance of 0.0160 or less at 365 nm wavelength light per 1 μm of photosensitive layer thickness.

[0017] Another embodiment of the present disclosure, a method for producing a laminate, includes placing the photosensitive layer of the photosensitive element on a substrate, photocuring a portion of the photosensitive layer, and removing the uncured portion of the photosensitive layer to form a resist pattern.

[0018] In one embodiment of the photosensitive element, the support may be a resin film, for example, a polyester film such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polyethylene-2,6-naphthalate (PEN); a polyolefin film such as a polyethylene film or a polypropylene film;

[0019] The thickness of the resin film is optional, but from the viewpoint of ease of handling, it may be, for example, 1 μm or more, 5 μm or more, or 10 μm or more. It may also be 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less. The thickness of the resin film may be in the range of 1 to 100 μm.

[0020] The haze value of the resin film is preferably as low as possible from the viewpoint of exposure efficiency during laminate production, and may be, for example, 5.0% or less, 1.5% or less, 1.0% or less, or 0.5% or less. The haze value of the resin film may be in the range of 0.01 to 5.0%. The haze value of the resin film can be measured using a commercially available haze meter or turbidity meter in accordance with the method specified in JIS K7105. An example of a commercially available turbidity meter is the "NDH-5000" manufactured by Nippon Denshoku Industries Co., Ltd.

[0021] In one embodiment of the photosensitive element, the photosensitive layer has an absorbance of 0.0160 or less for light having a wavelength of 365 nm per 1 μm of photosensitive layer thickness. Light having a wavelength of 365 nm is primarily used when drawing resist patterns using a projection exposure machine (stepper). Since the photosensitive layer has an absorbance of 0.0160 or less for light having a wavelength of 365 nm per 1 μm of photosensitive layer thickness, a resist pattern with high rectangularity can be obtained.

[0022] In the present disclosure, the absorbance values ​​of the photosensitive layer, photosensitive element, etc. are values ​​measured under the following conditions: Measuring instrument: UV-visible spectrophotometer (Hitachi Spectrophotometer U-3310 manufactured by Hitachi High-Technologies Corporation) Measurement temperature and environment: 20°C, in a clean room environment Slit width: 2 nm Scan speed: 300 nm / min Sampling interval: 0.50 nm Measurement range: 500 nm to 200 nm

[0023] The absorbance of the photosensitive layer at light having a wavelength of 365 nm may be 0.0158 or less, or may be 0.0155 or less, per 1 μm of thickness. Furthermore, when the absorbance of the photosensitive layer at light having a wavelength of 365 nm is 0.0120 or more, per 1 μm of thickness, the photosensitive element has an excellent balance between the rectangularity of the resist pattern and the photosensitivity of the photosensitive layer. The absorbance of the photosensitive layer at light having a wavelength of 365 nm may be 0.0135 or more, 0.0140 or more, or 0.0150 or more, per 1 μm of thickness of the photosensitive layer.

[0024] Furthermore, the photosensitive layer in one embodiment of the photosensitive element may have an absorbance of 0.0120 or more for light with a wavelength of 405 nm per 1 μm of photosensitive layer thickness. Light with a wavelength of 405 nm is light that is mainly used when drawing a resist pattern using a direct imaging exposure machine (DI). When the absorbance of the photosensitive layer for light with a wavelength of 365 nm is 0.0160 or less per 1 μm of photosensitive layer thickness, and the absorbance of light with a wavelength of 405 nm is 0.0120 or more per 1 μm of photosensitive layer thickness, the photosensitive element of one embodiment is a photosensitive element that can accommodate multiple types of light with different wavelengths. Specifically, in both exposure with light with a wavelength of 365 nm and exposure with light with a wavelength of 405 nm, the photosensitive element has an excellent balance between the rectangularity of the resist pattern and the photosensitivity of the photosensitive layer.

[0025] The absorbance of the photosensitive layer at light having a wavelength of 405 nm per 1 μm of photosensitive layer thickness may be 0.0122 or more, or 0.0125 or more. Also, it may be 0.0140 or less, or 0.0135 or less. The absorbance of the photosensitive layer at light having a wavelength of 405 nm per 1 μm of photosensitive layer thickness may be in the range of 0.0120 to 0.0140 per 1 μm of photosensitive layer thickness.

[0026] In one embodiment of the photosensitive element, the thickness of the photosensitive layer is adjusted appropriately depending on the desired use of the photosensitive element, the thickness of the intended resist pattern, and the like. The thickness of the photosensitive layer may be, for example, 5 μm or more, 10 μm or more, or 15 μm or more. It may also be 40 μm or less, 35 μm or less, or 30 μm or less. The thickness of the photosensitive layer may be in the range of 5 to 40 μm.

[0027] The photosensitive layer may be, for example, a photosensitive resin composition containing a binder resin, a photopolymerizable compound, a polymerization initiator, a photosensitizer, and a polymerization inhibitor, although the specific embodiment of the photosensitive layer is not particularly limited as long as it is capable of forming a resist pattern by light irradiation.

[0028] The binder resin may be used alone or in combination of two or more kinds.

[0029] The molecular weight of the binder resin is not particularly limited, but since a photosensitive resin composition having excellent film-forming properties and adhesion to a support is obtained, the weight-average molecular weight (Mw) may be, for example, 5,000 or more, 10,000 or more, or 20,000 or more. Furthermore, since a photosensitive layer having excellent developability is obtained, the weight-average molecular weight (Mw) may be, for example, 100,000 or less, 80,000 or less, or 50,000 or less. The weight-average molecular weight (Mw) of the binder resin may be in the range of 5,000 to 100,000. The dispersity (Mw / Mn) of the binder resin is not particularly limited, but may be, for example, in the range of 1.0 to 3.0.

[0030] When the photosensitive element is used for alkaline development, it is preferable that the binder resin has an acidic group such as a carboxy group, since this results in a photosensitive layer with excellent alkaline developability. The acid value of the binder resin may be, for example, 80 mgKOH / g or more, 100 mgKOH / g or more, or 150 mgKOH / g or more. It may also be 250 mgKOH / g or less, 220 mgKOH / g or less, or 210 mgKOH / g or less. The acid value of the binder resin may be in the range of 80 to 250 mgKOH / g.

[0031] In the present disclosure, the acid value of a binder resin is a value measured by the following method. First, 30 g of acetone is added to 1 g of the binder resin to be measured for acid value, and the mixture is dissolved uniformly. Next, an appropriate amount of phenolphthalein as an indicator is added to the acetone solution of the binder resin, and then titration is performed using a 0.1 N aqueous potassium hydroxide solution. The acid value can be calculated from the amount of aqueous potassium hydroxide solution required to neutralize the acetone solution of the binder resin.

[0032] The binder resin is not particularly limited in type, and a wide variety of resins can be used, but an example of such a resin is an acrylic resin. Examples of acrylic resins include polymers of compounds having a (meth)acryloyl group. In addition to compounds having a (meth)acryloyl group, compounds having a polymerizable group other than a (meth)acryloyl group may also be used in combination.

[0033] Examples of the compound having a (meth)acryloyl group include alkyl (meth)acrylate compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; halogenated alkyl (meth)acrylate compounds such as 2,2,2-trifluoroethyl (meth)acrylate and 2,2,3,3-tetrafluoropropyl (meth)acrylate; and water-soluble alkyl (meth)acrylate compounds such as hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Examples of the (meth)acrylate compound include an acid group-containing (meth)acrylate compound; an alicyclic (meth)acrylate compound such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, or dicyclopentenyl (meth)acrylate; an aromatic ring-containing (meth)acrylate compound such as phenyl (meth)acrylate, benzyl (meth)acrylate, or phenoxyethyl (meth)acrylate; a cyclic ether structure-containing (meth)acrylate compound such as tetrahydrofurfuryl (meth)acrylate or glycidyl (meth)acrylate; or an acid group-containing (meth)acrylate compound such as (meth)acrylic acid. These compounds may be used alone or in combination of two or more.

[0034] Examples of compounds having a polymerizable group other than a (meth)acryloyl group include styrene compounds such as styrene and α-methylstyrene, and maleic acid compounds such as maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and monoisopropyl maleate. These may be used alone or in combination of two or more.

[0035] When the photosensitive element is used for alkaline development, the acrylic resin preferably has an acidic group. Examples of acrylic resins having an acidic group include those having a divalent group represented by the following general formula (1):

[0036]

[0037] [In formula (1), R １ is a hydrogen atom or a methyl group.

[0038] The proportion of the divalent group represented by general formula (1) in the acrylic resin is adjusted appropriately depending on the desired acid group of the acrylic resin, but may be, for example, 10% by mass or more, 15% by mass or more, or 20% by mass or more. It may also be 50% by mass or less, 40% by mass or less, or 35% by mass or less. The proportion of the divalent group represented by general formula (1) in the acrylic resin may be in the range of 10 to 50% by mass.

[0039] The acrylic resin may have, in addition to the divalent group represented by general formula (1), one or more divalent groups represented by any of the following general formulas (2) to (4).

[0040] [In general formula (2), R ２ is a hydrogen atom or a methyl group. ３ is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a hydroxyl group, and l is 0 or an integer of 1 to 5. When l is 2 or more, multiple R ３ may all be different, or some or all may be the same. ４ is a hydrogen atom or a methyl group. ５ is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a hydroxyl group, and m is 0 or an integer of 1 to 5. When m is 2 or more, multiple R ５ may all be different, or some or all may be the same. ６ is a hydrogen atom or a methyl group. ７ is an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 4 carbon atoms.

[0041] R in general formula (2) ３ and R in general formula (3) ５is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a hydroxyl group. Specific examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Specific examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, and an isopropyloxy group. l in general formula (2) and m in general formula (3) are 0 or an integer of 1 to 5. l and m may be 0 or 1, or may be 0.

[0042] R in general formula (4) ７ is an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 4 carbon atoms. Specific examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an s-butyl group, and an isobutyl group. Specific examples of the hydroxyalkyl group having 1 to 4 carbon atoms include an alkyl group having 1 to 4 carbon atoms in which one or more hydrogen atoms have been substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, and a hydroxybutyl group.

[0043] In the acrylic resin, the proportion of the divalent group represented by general formula (2) may be, for example, 20% by mass or more, 30% by mass or more, or 40% by mass or more. It may also be 70% by mass or less, 65% by mass or less, or 60% by mass or less. In the acrylic resin, the proportion of the divalent group represented by general formula (2) may be in the range of 20 to 70% by mass.

[0044] In the acrylic resin, the proportion of the divalent group represented by general formula (3) may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more. It may also be 50% by mass or less, 40% by mass or less, or 30% by mass or less. In the acrylic resin (A1), the proportion of the divalent group represented by general formula (3) may be in the range of 5 to 50% by mass.

[0045] In the acrylic resin, the proportion of the divalent group represented by general formula (4) may be, for example, 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more. It may also be 30% by mass or less, 20% by mass or less, or 10% by mass or less. In the acrylic resin (A1), the proportion of the divalent group represented by general formula (4) may be in the range of 0.1 to 30% by mass.

[0046] In the acrylic resin, the total proportion of divalent groups represented by any one of general formulas (1) to (4) may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0047] The proportion of the acrylic resin relative to the total amount of the binder resin may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0048] The photopolymerizable compounds may be used alone or in combination of two or more.

[0049] The photopolymerizable compound preferably has a molecular weight of 4,000 or less, since this results in a photosensitive resin composition with high sensitivity and resolution. The molecular weight of the photopolymerizable compound may be 3,000 or less, or 2,000 or less. It may also be 100 or more, 200 or more, or 500 or more. The molecular weight of the photopolymerizable compound may be in the range of 100 to 4,000.

[0050] Specifically, the photopolymerizable compound may be a compound having a photopolymerizable group such as a (meth)acryloyl group, a vinyl group, etc. Examples of the photopolymerizable compound include a monofunctional photopolymerizable compound having one photopolymerizable group in one molecule (hereinafter sometimes referred to as a "monofunctional compound"), a bifunctional photopolymerizable compound having two photopolymerizable groups in one molecule (hereinafter sometimes referred to as a "bifunctional compound"), and a polyfunctional photopolymerizable compound having three or more photopolymerizable groups in one molecule (hereinafter sometimes referred to as a "polyfunctional compound").

[0051] Examples of the monofunctional compound include alkyl (meth)acrylate compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate; (meth)acrylate compounds containing an alicyclic structure such as dicyclopentenyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate compounds containing an aromatic ring structure such as benzyl (meth)acrylate and nonylphenoxy (meth)acrylate; (meth)acrylate compounds containing a heterocyclic structure such as tetramethylpiperidyl (meth)acrylate and pentamethylpiperidyl (meth)acrylate; and (poly)alkylene oxide-modified compounds thereof; and phthalate compounds such as γ-chloro-β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate and β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate.

[0052] Examples of bifunctional compounds include di(meth)acrylates of aliphatic polyols and (poly)alkylene oxide-modified compounds thereof, di(meth)acrylates of bisphenols and (poly)alkylene oxide-modified compounds thereof, di(meth)acrylates of bifunctional epoxy compounds and (poly)alkylene oxide-modified compounds thereof, polyalkylene glycol di(meth)acrylates, and urethane di(meth)acrylates.

[0053] Regarding the di(meth)acrylate of an aliphatic polyol, examples of the aliphatic polyol include ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, and glycerin.

[0054] In the di(meth)acrylate of bisphenol, the bisphenol preferably does not contain a halogen atom in the molecular structure, and examples thereof include bisphenol A, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, and bisphenol F.

[0055] Regarding the di(meth)acrylate of a difunctional epoxy compound, examples of the difunctional epoxy compound include diglycidyl ethers of biphenol, bisphenol, etc. Examples of bisphenols include those mentioned above.

[0056] With regard to polyalkylene glycol di(meth)acrylate, examples of alkylene oxide groups in the molecular structure include ethylene oxide, propylene oxide, and butylene oxide. The polyalkylene glycol di(meth)acrylate may have multiple types of alkylene oxide groups in one molecule, and in this case, it may be a block type in which the same alkylene oxide groups are consecutive, or a random type in which multiple types of alkylene oxide groups are randomly connected. The total number of alkylene oxide groups in one molecule may be 6 or more, 10 or more, or 12 or more. It may also be 32 or less, 28 or less, or 24 or less. The total number of alkylene oxide groups in one molecule of the polyalkylene glycol di(meth)acrylate may be in the range of 6 to 32. If the number of alkylene oxide groups in one molecule is not constant due to reasons such as industrial production, the average value may be in the range of 6 to 32.

[0057] Examples of the urethane di(meth)acrylate include a urethane reaction product of a hydroxyalkyl (meth)acrylate with a diisocyanate compound, and a (poly)alkylene oxide-modified compound thereof. Examples of the diisocyanate compound include hexamethylene diisocyanate, isophorone diisocyanate, and toluene diisocyanate.

[0058] Examples of polyfunctional compounds include poly(meth)acrylates of tri- or higher functional aliphatic polyols and (poly)alkylene oxide-modified compounds thereof, and poly(meth)acrylates of tri- or higher functional epoxy compounds and (poly)alkylene oxide-modified compounds thereof.

[0059] Regarding the poly(meth)acrylate of a trifunctional or higher aliphatic polyol, examples of the trifunctional or higher aliphatic polyol include trimethylolethane, trimethylolpropane, glycerin, tetramethylolmethane, pentaerythritol, dipentaerythritol, etc. Specific examples of these poly(meth)acrylates include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.

[0060] With respect to the (poly)alkylene oxide-modified compounds in the monofunctional, bifunctional, and polyfunctional compounds, examples of the alkylene oxide group include ethylene oxide, propylene oxide, and butylene oxide. The (poly)alkylene oxide-modified compound may have multiple types of alkylene oxide groups in one molecule. The polyalkylene oxide group may be a block type in which the same alkylene oxide group is consecutive, or a random type in which multiple types of alkylene oxide groups are randomly linked. In the (poly)alkylene oxide-modified compound, the total number of alkylene oxide groups in one molecule may be in the range of 2 to 20. If the number of alkylene oxide groups in one molecule is not constant due to reasons such as industrial production, the average value may be in the range of 2 to 20.

[0061] Among these photopolymerizable compounds, it is preferable to include at least one selected from the group consisting of bifunctional compounds and polyfunctional compounds, since this results in a photosensitive resin composition with high sensitivity and resolution. The total proportion of the bifunctional compounds and polyfunctional compounds to the entire photopolymerizable compounds may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or even 100% by mass.

[0062] Furthermore, the photopolymerizable compound preferably contains a bifunctional compound, since this results in a photosensitive resin composition having an excellent balance between sensitivity, resolution, and substrate adhesion. The ratio of the bifunctional compound to the total photopolymerizable compound may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or even 100% by mass.

[0063] Among the bifunctional compounds, a (poly)alkylene oxide-modified compound of bisphenol di(meth)acrylate (hereinafter, this may be referred to as "bifunctional compound (1)") and a polyalkylene glycol di(meth)acrylate (hereinafter, this may be referred to as "bifunctional compound (2)") are particularly preferred. The total proportion of bifunctional compound (1) and bifunctional compound (2) relative to the total photopolymerizable compound may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or even 100% by mass.

[0064] The mass ratio of the bifunctional compound (1) to the bifunctional compound (2) is adjusted appropriately depending on the desired photosensitive layer performance, etc. For example, the proportion of the bifunctional compound (1) to the total of the two may be 50 mass% or more, 70 mass% or more, or 85 mass% or more. It may also be 99 mass% or less, 97 mass% or less, or 95 mass% or less. The proportion of the bifunctional compound (1) to the total of the bifunctional compound (1) and the bifunctional compound (2) may be in the range of 50 to 99 mass%.

[0065] Examples of the bifunctional compound (1) include compounds represented by the following general formula (5).

[0066]

[0067] [R in general formula (5)] ８ are each independently a hydrogen atom, a methyl group, an ethyl group, or a phenyl group. ９ , R １０ are each independently an alkylene group having 2 to 4 carbon atoms. １１ are each independently a hydrogen atom or a methyl group; and i and j are each an integer of 1 or greater.

[0068] R in general formula (5) ９ , R １０ are each independently an alkylene group having 2 to 4 carbon atoms, specifically an ethylene group, a propylene group, or a butylene group. When i and j are each 2 or more, a plurality of R ９ , R １０ may all be different, or some or all may be the same.

[0069] In general formula (5), i and j are each an integer of 1 or more. i and j may be in the range of 1 to 12. When the number of alkylene oxide groups in one molecule is not constant due to reasons such as industrial production, the average value may be in the range of 1 to 12. Furthermore, the sum of i and j may be in the range of 2 to 20. When the number of alkylene oxide groups in one molecule is not constant due to reasons such as industrial production, the average value may be in the range of 2 to 20.

[0070] As the bifunctional compound (1), multiple types of compounds having different total numbers of alkylene oxide groups per molecule may be used in combination. Specifically, a bifunctional compound (1) having a total number (or average value) of alkylene oxide groups per molecule in the range of 2 to 6 may be used in combination with a bifunctional compound (1) having a total number (or average value) of alkylene oxide groups per molecule in the range of 8 to 14. The mass ratio of the two may be, for example, 1% by mass or more, 5% by mass or more, or 10% by mass or more of the compounds having a number (or average value) of alkylene oxide groups per molecule in the range of 2 to 6 relative to the total mass of the two. Alternatively, the ratio may be 45% by mass or less, 30% by mass or less, or 20% by mass or less. This value may be in the range of 1 to 45% by mass.

[0071] Examples of the bifunctional compound (2) include compounds represented by the following general formula (6).

[0072]

[0073] [In the general formula (6), k is an integer of 2 or more. １２ are each independently an alkylene group having 2 to 4 carbon atoms.１３ are each independently a hydrogen atom or a methyl group.

[0074] In general formula (6), k is an integer of 2 or more. k may be 6 or more, 10 or more, or 12 or more. It may also be 32 or less, 28 or less, or 24 or less. The value of k may be, for example, in the range of 6 to 32. When the number of alkylene oxide groups in one molecule is not constant due to the convenience of industrial production or the like, the average value may be in the range of 6 to 32.

[0075] Multiple R's in the formula １２ are each independently an alkylene group having 2 to 4 carbon atoms, specifically an ethylene group, a propylene group, or a butylene group. As described above, the bifunctional compound (2) may have multiple types of alkylene oxide groups in one molecule, and in this case, they may be of a block type in which the same alkylene oxide groups are consecutive, or of a random type in which multiple types of alkylene oxide groups are randomly linked. The bifunctional compound (2) may be, for example, a compound represented by the following general formula (6-1):

[0076]

[0077] [In general formula (6-1), p, q, and r each independently represent an integer of 1 or more. R １３ are each independently a hydrogen atom or a methyl group.

[0078] In general formula (6-1), p, q, and r each independently represent an integer of 1 or greater. p, q, and r may, for example, each independently range from 2 to 20. The sum of p and r may range from 4 to 12, or may range from 4 to 8. q may range from 8 to 16. When the number of alkylene oxide groups in one molecule is not constant due to reasons such as industrial production, each value may be an average value.

[0079] In the photosensitive resin composition, the ratio of the binder resin to the photopolymerizable compound can be appropriately adjusted depending on the desired physical properties of the photosensitive layer, such as the desired photosensitivity, developability, resolution, etc. For example, the ratio of the binder resin to the total mass of the binder resin and the photopolymerizable compound may be 20% by mass or more, 30% by mass or more, or 45% by mass or more. It may also be 85% by mass or less, 75% by mass or less, or 65% by mass or less. The ratio of the binder resin to the total mass of the binder resin and the photopolymerizable compound may be in the range of 20 to 85% by mass.

[0080] The polymerization initiator may be used alone or in combination of two or more kinds.

[0081] The type of polymerization initiator is not particularly limited, and a wide variety of initiators commonly used in the field of photosensitive resin compositions can be used. Specific examples of the polymerization initiator include hydrogen abstraction type radical generators such as benzophenone compounds, thioxanthone compounds, fluorenone compounds, acridine compounds, and hexaarylbiimidazole 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.

[0082] The amount of polymerization initiator added is adjusted appropriately depending on the desired photosensitivity, developability, resolution, etc., but may be, for example, 0.1% by mass or more, 1% by mass or more, or 3% by mass or more relative to the total mass of the binder resin and the photopolymerizable compound. It may also be 15% by mass or less, 10% by mass or less, or 7% by mass or less. The amount of polymerization initiator added may be in the range of 0.1 to 15% by mass relative to the total mass of the binder resin and the photopolymerizable compound.

[0083] The photosensitizer may be used alone or in combination of two or more kinds.

[0084] The type of photosensitizer is not particularly limited, and a wide variety of those commonly used in the field of photosensitive resin compositions can be used. Specific examples of the photosensitizer include anthracene compounds, benzophenone compounds, pyrazoline compounds, coumarin compounds, xanthone compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, triazine compounds, thiophene compounds, naphthalimide compounds, triarylamine compounds, and aminoacridine compounds.

[0085] In one embodiment, when it is desired to make the photosensitive element compatible with multiple types of light having different wavelengths, specifically, when it is desired to make the photosensitive element compatible with both exposure to light having a wavelength of 365 nm and exposure to light having a wavelength of 405 nm, it is preferable to use an anthracene compound as the photosensitizer. The ratio of the anthracene compound to the total amount of the photosensitizer may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or even 100% by mass.

[0086] Specific examples of anthracene compounds include compounds having substituents at the 9th and 10th positions of anthracene. Examples of the substituents include an alkoxy group having 1 to 6 carbon atoms and an aryl group. Among these, 9,10-dialkoxyanthracene compounds having alkoxy groups having 1 to 6 carbon atoms at the 9th and 10th positions of the photosensitive layer are preferred.

[0087] The amount of photosensitizer added is adjusted appropriately depending on the desired photosensitivity, developability, resolution, etc., but may be, for example, 0.01% by mass or more, 0.1% by mass or more, or 0.3% by mass or more, relative to the total mass of the binder resin and the photopolymerizable compound. It may also be 5% by mass or less, 2% by mass or less, or 0.6% by mass or less. The amount of photosensitizer added may be in the range of 0.01 to 5% by mass, relative to the total mass of the binder resin and the photopolymerizable compound.

[0088] The polymerization inhibitor may be used alone or in combination of two or more kinds.

[0089] The type of polymerization inhibitor is not particularly limited, and a wide variety of those commonly used in the field of photosensitive resin compositions can be used. Specific examples of polymerization inhibitors include a compound represented by the following general formula (7) and a compound having a 2,2,6,6-tetramethylpiperidine-1-oxyl structure (hereinafter sometimes referred to as a "TEMPO compound").

[0090]

[0091] [R in general formula (7) １４ is any one of a halogen atom, an aliphatic hydrocarbon group, an alkoxy group, an aryl group, and an aryloxy group; t is 2 or 3, s is 0 or an integer of 1 to 4, and t+s is 6 or less.]

[0092] Examples of the halogen atom include fluorine, chlorine, bromine, and iodine.

[0093] The aliphatic hydrocarbon group may have any structure, such as a linear one, one having a branched structure, or one having an alicyclic structure. The number of carbon atoms in the aliphatic hydrocarbon group is not particularly limited and may be, for example, 1 or more and 8 or less. Specific examples of the aliphatic hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, a neopentyl group, a 1-methylbutyl group, a 3-methylbutyl group, a 1,1-dimethylpropyl group, an n-hexyl group, an isohexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, and a 1,1,3,3-tetramethylbutyl group; and alicyclic alkyl groups such as a cyclohexyl group.

[0094] Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, a sec-butyloxy group, an isobutyloxy group, and a t-butyloxy group.

[0095] Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, etc. Examples of the aryloxy group include a phenyloxy group, a tolyloxy group, a xylyloxy group, a mesityloxy group, a naphthyloxy group, etc.

[0096] Specific examples of the compound represented by general formula (7) include catechol compounds such as catechol, 3-methylcatechol, 4-methylcatechol, 3-ethylcatechol, 4-ethylcatechol, 3-propylcatechol, 4-propylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, and 3,5-di-tert-butylcatechol; resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 2-ethylresorcinol, 4-ethylresorcinol, 5-ethylresorcinol, and 2- Examples of the resorcinol compound include propyl resorcinol, 4-propyl resorcinol, 5-propyl resorcinol, 2-n-butyl resorcinol, 4-n-butyl resorcinol, 5-n-butyl resorcinol, 2-tert-butyl resorcinol, 4-tert-butyl resorcinol, and 5-tert-butyl resorcinol; hydroquinone compounds such as 1,4-hydroquinone, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone; and trifunctional phenol compounds such as pyrogallol and phloroglucinol.

[0097] Specific examples of the TEMPO compound include 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-acetyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-cyclohexylcarbonyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

[0098] In one embodiment, when it is desired to make the photosensitive element adaptable to a plurality of types of light having different wavelengths, specifically, when it is desired to make the photosensitive element adaptable to both exposure with light having a wavelength of 365 nm and exposure with light having a wavelength of 405 nm, it is preferable to use a compound represented by general formula (7), and it is more preferable to use a catechol compound.Furthermore, it is preferable to use a compound represented by general formula (7) in combination with a TEMPO compound.

[0099] The ratio of the compound represented by general formula (7) to the total amount of polymerization inhibitor is adjusted appropriately depending on the desired photosensitivity, developability, resolution, etc., and may be, for example, 50% by mass or more, 60% by mass or more, 68% by mass or more, or 100% by mass. It may also be 99% by mass or less, 90% by mass or less, or 80% by mass or less. The ratio of the compound represented by general formula (7) to the total amount of polymerization inhibitor may be in the range of 50 to 100% by mass.

[0100] The ratio of the TEMPO compound to the total amount of polymerization inhibitors is adjusted appropriately depending on the desired photosensitivity, developability, resolution, etc., and may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more. It may also be 40% by mass or less, 35% by mass or less, or 30% by mass or less. The ratio of the TEMPO compound to the total amount of polymerization inhibitors may be in the range of 5 to 40% by mass.

[0101] When the compound represented by general formula (7) and the TEMPO compound are used in combination, the total proportion of the compound represented by general formula (7) and the TEMPO compound relative to the total amount of the polymerization inhibitor may be 80% by mass or more, 90% by mass or more, or even 100% by mass.

[0102] When the compound represented by general formula (7) and the TEMPO compound are used in combination, the ratio of the two is appropriately adjusted depending on the desired photosensitivity, developability, resolution, etc., but for example, the ratio of the compound represented by general formula (7) to the total mass of the two may be 50% by mass or more, 60% by mass or more, or 68% by mass or more. It may also be 99% by mass or less, 90% by mass or less, or 80% by mass or less. The ratio of the compound represented by general formula (7) to the total mass of the compound represented by general formula (7) and the TEMPO compound may be in the range of 50 to 99% by mass.

[0103] The amount of polymerization inhibitor added is adjusted appropriately depending on the desired photosensitivity, developability, resolution, etc., but may be, for example, 0.01% by mass or more, 0.03% by mass or more, or 0.032% by mass or more, relative to the total mass of the binder resin and the photopolymerizable compound. It may also be 0.5% by mass or less, 0.1% by mass or less, or 0.08% by mass or less. The amount of polymerization inhibitor added may be in the range of 0.01 to 0.5% by mass, relative to the total mass of the binder resin and the photopolymerizable compound.

[0104] The amount of the compound represented by general formula (7) added among the polymerization inhibitors is adjusted as appropriate depending on the desired photosensitivity, developability, resolution, etc., and may be, for example, 0.01% by mass or more, 0.018% by mass or more, or 0.022% by mass or more, relative to the total mass of the binder resin and the photopolymerizable compound. It may also be 0.5% by mass or less, 0.1% by mass or less, or 0.08% by mass or less. The amount of the compound represented by general formula (7) added may be in the range of 0.01 to 0.5% by mass, relative to the total mass of the binder resin and the photopolymerizable compound.

[0105] The photosensitive resin composition may contain other components in addition to the binder resin, photopolymerizable compound, polymerization initiator, photosensitizer, and polymerization inhibitor, such as a hydrogen donor, an adhesion aid, a leveling agent, a dye, a rust inhibitor, a stabilizer, a plasticizer, an antifoaming agent, a flame retardant, a release promoter, and an organic solvent.

[0106] A hydrogen donor is mainly used when a hydrogen abstraction type radical generator is used as a polymerization initiator. Specifically, the hydrogen donor donates hydrogen to the hydrogen abstraction type radical generator, and the newly generated radical functions as a polymerization initiator. One type of hydrogen donor may be used alone, or two or more types may be used in combination. Specific examples of hydrogen donors include bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, and tris[4-(dimethylamino)phenyl]methane (also known as leuco crystal violet (LCV)). Among these, tris[4-(dimethylamino)phenyl]methane is preferred.

[0107] The amount of the hydrogen donor added may be, for example, 0.05% by mass or more, 0.1% by mass or more, or 0.3% by mass or more, relative to the total mass of the binder resin and the photopolymerizable compound. It may also be 5% by mass or less, 3% by mass or less, or 1% by mass or less. The amount of the hydrogen donor added may be in the range of 0.05 to 5% by mass, relative to the total mass of the binder resin and the photopolymerizable compound.

[0108] Adhesion aids, leveling agents, dyes, rust inhibitors, plasticizers, defoamers, flame retardants, and release promoters are optional components that can be used appropriately depending on the desired performance of the photosensitive layer. These additives can be widely used and are commonly used in the field of photosensitive resin compositions. The amount of these additives added may be, for example, in the range of 0.01 to 10% by mass, based on the total mass of the binder resin and the photopolymerizable compound.

[0109] The organic solvent is a component used primarily to adjust the viscosity of the photosensitive resin composition and improve workability during the production of photosensitive elements. One type of organic solvent may be used alone, or two or more types may be used in combination. The proportion of the organic solvent in the photosensitive resin composition is appropriately adjusted depending on the desired viscosity, the desired film thickness of the photosensitive resin composition layer in the photosensitive element, and the like. For example, it may be 20% by mass or more, 30% by mass or more, or 40% by mass or more. It may also be 90% by mass or less, 80% by mass or less, or 70% by mass or less. The proportion of the organic solvent in the photosensitive resin composition may be in the range of 20 to 90% by mass.

[0110] Specific examples of the organic solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol and ethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, and propylene glycol dimethyl ether; glycol ether acetates such as propylene glycol 1-monomethyl ether 2-acetate; carbonate esters such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP).

[0111] The photosensitive element of one embodiment can be formed, for example, by applying a photosensitive resin composition to a support to a desired thickness to form a photosensitive layer. When the photosensitive resin composition contains an organic solvent, it is preferable to volatilize the organic solvent so that the content of the organic solvent in the photosensitive layer is 2% by mass or less. The drying temperature may be, for example, in the range of 60 to 150°C. The drying time may be in the range of 5 to 30 minutes. The photosensitive resin composition can be applied using, for example, a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater.

[0112] The photosensitive element may further have a protective film on the surface of the photosensitive layer. Examples of the protective film include polyester films such as polyethylene terephthalate, and polyolefin films such as polypropylene and polyethylene. The thickness of the protective film may be in the range of, for example, 1 to 100 μm.

[0113] When the support is a resin film, the photosensitive element may be in the form of a sheet or wound into a roll. When wound into a roll, the resin film may be wound on the outside.

[0114] In one embodiment, a method for producing a laminate includes placing a photosensitive layer of a photosensitive element on a substrate, photocuring a portion of the photosensitive layer, and removing the uncured portion of the photosensitive layer to form a resist pattern.

[0115] Examples of the substrate include a substrate having an insulating layer and a conductor layer formed on the insulating layer, a metal substrate for manufacturing a metal mask, a die pad such as an alloy substrate, etc. The circuit-forming substrate may be multilayered and have wiring formed therein, or may have small-diameter through holes.

[0116] The photosensitive layer of the photosensitive element may be disposed on the substrate by, for example, pressing the photosensitive layer of the photosensitive element onto the substrate. In this case, either or both of the substrate and the photosensitive element may be heated. The heating temperature may be, for example, about 60 to 120°C. The pressing may also be performed under reduced pressure. The pressure during pressing may be, for example, 0.1 to 1.0 MPa (1 to 10 kgf / cm). ２ ) range.

[0117] The light source of actinic rays used to photocure a portion of the photosensitive layer can be a known light source, and examples thereof include those that effectively emit ultraviolet light, visible light, and the like, such as 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, and semiconductor lasers. The wavelength of the actinic rays may be in the range of 340 nm to 430 nm. Examples of exposure methods include projection exposure and direct writing exposure. When the support of the photosensitive element is transparent to irradiation light, actinic rays may be irradiated through the support, or the support may be removed after irradiation with actinic rays. When the support is light-shielding, actinic rays are irradiated after removing the support.

[0118] After a portion of the photosensitive layer is photocured, post-exposure baking (PEB) may be performed before removing the uncured portion. The temperature when performing PEB may be 50 to 100° C. As the heater, a hot plate, a box-type dryer, a heating roll, or the like may be used.

[0119] Removal of uncured portions of a photosensitive layer, so-called development, is roughly divided into wet development and dry development, with wet development being widely used. Examples of developers used in wet development include alkaline aqueous solutions, water-based developers, and organic solvent-based developers, and a developer appropriate for the photosensitive resin composition is selected and used. Development can be carried out by known methods, such as dipping, bathing, spraying, swinging immersion, brushing, and scraping. From the viewpoint of improving resolution, high-pressure spraying is preferably used. Furthermore, two or more development methods may be used in combination, if necessary.

[0120] Examples of alkaline aqueous solutions include aqueous solutions of alkali hydroxides such as hydroxides of lithium, sodium, or potassium; alkali carbonates such as carbonates or bicarbonates of lithium, sodium, potassium, or ammonium; 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, morpholine, and the like.

[0121] Examples of preferred alkaline aqueous solutions include 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, and a dilute solution of 0.1 to 5% by mass sodium tetraborate (borax). The pH of the alkaline aqueous solution is preferably in the range of 9 to 11. The temperature of the alkaline aqueous solution may be adjusted according to the developability of the photosensitive resin composition layer. The alkaline aqueous solution may also contain a surfactant, an antifoaming agent, a small amount of an organic solvent to promote development, and the like.

[0122] Examples of organic solvent-based developers include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, γ-butyrolactone, etc. To prevent ignition, it is preferable to add water to these organic solvent-based developers in an amount of 1 to 20% by mass.

[0123] After removing the uncured portion of the photosensitive layer, the resist pattern may be further cured by heating or exposure, if necessary. The heating temperature may be in the range of 60 to 250°C. The light dose during exposure is 0.2 to 10 J / cm. ２ may be in the range of

[0124] The method for producing a laminate according to one embodiment may further include forming a conductive pattern by subjecting the substrate on which the resist pattern has been formed to a plating process, an etching process, or the like.

[0125] The substrate is plated or etched using the formed resist pattern as a mask on the conductor layer. Examples of plating methods include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, Watts bath (nickel sulfate-nickel chloride) plating and nickel plating such as nickel sulfamate, and gold plating such as hard gold plating and soft gold plating. Examples of etching solutions include cupric chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide etching solution.

[0126] After forming the conductive pattern by plating or etching, the resist pattern on the substrate may be removed. The resist pattern can be removed, for example, with an alkaline aqueous solution that is stronger than the alkaline aqueous solution used to remove the uncured portion of the photosensitive layer. Examples of strong alkaline aqueous solutions include a 1 to 10 mass % sodium hydroxide aqueous solution and a 1 to 10 mass % potassium hydroxide aqueous solution. Examples of the removal method include an immersion method and a spray method, and the immersion method and the spray method may be used alone or in combination. When the resist pattern is removed after plating, the conductive layer that was covered with the resist pattern may be further etched to form a conductive pattern.

[0127] Examples of embodiments are listed below. The present invention is not limited to the following embodiments. <1> A photosensitive element comprising a support and a photosensitive layer located on the support, wherein the absorbance of the photosensitive layer at light having a wavelength of 365 nm is 0.0160 or less per 1 μm of thickness of the photosensitive layer.

[0128] <2> The photosensitive element according to <1>, wherein the photosensitive layer has an absorbance of 0.0120 or more at a wavelength of 365 nm per 1 μm of thickness of the photosensitive layer.

[0129] <3> The photosensitive element according to <1> or <2>, wherein the photosensitive layer has an absorbance of 0.012 or more per 1 μm of photosensitive layer thickness at a wavelength of 405 nm.

[0130] <4> The photosensitive element according to any one of <1> to <3>, wherein the photosensitive layer has a thickness in the range of 5 to 40 μm.

[0131] <5> The photosensitive element according to any one of <1> to <4>, wherein the photosensitive layer is formed from a photosensitive resin composition containing a binder resin, a photopolymerizable compound, a polymerization initiator, a photosensitizer, and a polymerization inhibitor.

[0132] <6> The photosensitive element according to <5>, wherein the photosensitizer is an anthracene compound.

[0133] <7> The photosensitive element according to <5> or <6>, wherein the polymerization inhibitor is a phenolic compound.

[0134] <8> A method for producing a laminate, comprising: placing a photosensitive layer of the photosensitive element according to any one of <1> to <7> on a substrate; photocuring a portion of the photosensitive layer; and removing an uncured portion of the photosensitive layer to form a resist pattern.

[0135] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0136] [Method for measuring 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) under the following GPC conditions.

[0137] Pump: Hitachi L-6000 type (trade name, manufactured by Hitachi, Ltd.) Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (all manufactured by Resonaq Technoservice Co., Ltd., trade names) Eluent: tetrahydrofuran Measurement temperature: 40°C Flow rate: 2.05 mL / min Detector: L-3300 type RI (trade name, manufactured by Hitachi, Ltd.)

[0138] [Details of each component used in the photosensitive resin composition] Binder resin solution: 49% by mass solution of acrylic resin used in the proportions of 50% by mass of styrene, 27% by mass of methacrylic acid, 20% by mass of benzyl methacrylate, and 3% by mass of 2-hydroxyethyl methacrylate. The solvent was a mixed solvent of ethylene glycol monomethyl ether and toluene (mass ratio 3:2), and the weight average molecular weight (Mw) of the acrylic resin was 35,000. Photopolymerizable compound (1): a polyethylene oxide-modified compound of bisphenol A dimethacrylate, the average total number of ethylene oxide groups per molecule was 10 (manufactured by Resonac Co., Ltd., "FA-321M"). Photopolymerizable compound (2): a polyethylene oxide-modified compound of bisphenol A dimethacrylate, the average total number of ethylene oxide groups per molecule was 2.6 (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester BP-2EM"). Photopolymerizable compound (3): a polyalkylene glycol di(meth)acrylate represented by the following general formula (6-2), the average sum of p and r was 6, and the average value of q was 12 (manufactured by Resonac Co., Ltd., "FA-024M").

[0139]

[0140] Polymerization initiator: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (BCIM, manufactured by Hampford Chemical Industries, Ltd.) Photosensitizer: 9,10-dibutoxyanthracene (DBA, manufactured by Kawasaki Chemical Industries, Ltd.) Polymerization inhibitor (1): 4-tert-butylcatechol ("Q-TBC-5P" manufactured by DIC Corporation) Polymerization inhibitor (2): 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl ("LA-7RD" manufactured by Adeka Corporation) Hydrogen donor: leuco crystal violet (tris[4-(dimethylamino)phenyl]methane) (LCV, manufactured by Yamada Chemical Co., Ltd.) Adhesion aid: mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol ("SF-808H" manufactured by Sanwa Chemical Industries, Ltd.) Dye: Malachite Green (Osaka Organic Chemical Industry Co., Ltd.) Stabilizer: Pentamethylpiperidyl methacrylate (Resonac Co., Ltd. "FA-711MM")

[0141] [Example 1] 114.28 parts by weight of binder resin solution (56 parts by weight of resin solids), 35 parts by weight of photopolymerizable compound (1), 5 parts by weight of photopolymerizable compound (2), 4 parts by weight of photopolymerizable compound (3), 6 parts by weight of polymerization initiator, 0.55 parts by weight of photosensitizer, 0.035 parts by weight of polymerization inhibitor (1), 0.01 parts by weight of polymerization inhibitor (2), 0.5 parts by weight of hydrogen donor, 0.5 parts by weight of adhesion aid, 0.02 parts by weight of dye, 1 part by weight of stabilizer, 10 parts by weight of acetone, 16 parts by weight of toluene, and 6 parts by weight of methanol were blended and mixed to produce a photosensitive resin composition. Photosensitive elements and laminates were produced using this photosensitive resin composition, and various evaluation tests were performed.

[0142] [Example 2 and Comparative Examples 1 to 3] Photosensitive resin compositions were produced in the same manner as in Example 1, except that the composition of the photosensitive resin composition produced in Example 1 was partially changed as shown in Table 1. Photosensitive elements and laminates were produced using these photosensitive resin compositions, and various evaluation tests were carried out.

[0143]

[0144] [Production of Photosensitive Element] The photosensitive resin composition obtained above was coated on a support (*1). It was dried in a hot air convection dryer at 80°C and 120°C to form a photosensitive layer with a film thickness of 25 μm. Subsequently, a PET film (*2) was laminated on the photosensitive layer as a protective film to obtain a photosensitive element. Support (*1): 16 μm thick polyethylene terephthalate film ("FS-31" manufactured by Toray Industries, Inc.) Protective film (*2): 20 μm thick polyethylene film (trade name "NF-15" manufactured by Tamapoly Co., Ltd.)

[0145] [Measurement of absorbance of photosensitive layer] Using an ultraviolet-visible spectrophotometer (*3), the absorbance of the photosensitive element was measured for light with a wavelength of 365 nm and light with a wavelength of 405 nm under the following measurement conditions. The absorbance of the photosensitive layer was evaluated by subtracting the absorbance values ​​of light with each wavelength measured for the support alone and the protective film alone from the measured absorbance of the photosensitive element. The results are shown in Table 2.

[0146] UV-visible spectrophotometer (*3): Hitachi High-Technologies Corporation "Hitachi Spectrophotometer U-3310" Temperature: 20°C (in a clean room environment) Slit width: 2 nm Scan speed: 300 nm / min Sampling interval: 0.50 nm Measurement range: 500 nm to 200 nm

[0147] [Evaluation of Rectangularity of Resist Pattern] The rectangularity of the resist pattern was evaluated for Laminates 3 and 5 produced as follows. The rectangularity was evaluated by measuring the top width and bottom width of the resist pattern and calculating the ratio. Measurements were taken at three locations and the evaluation was based on the average value. The results are shown in Table 2. The closer this ratio is to 1, the higher the rectangularity is, enabling more accurate circuit formation.

[0148] (Method for manufacturing laminate 1) The substrate (*4) was heated to 80°C, and while peeling off the protective film of the photosensitive element, the photosensitive element was laminated so that the photosensitive layer of the photosensitive element was in contact with the copper surface, to obtain laminate 1 as a laminate. Lamination was performed using a heat roll at 110°C under conditions of a pressure of 0.4 MPa and a roll speed of 1.5 m / min. Substrate (*4): "MCL-E-679" manufactured by Resonac Co., Ltd., a double-sided copper-clad laminate having 35 μm-thick copper foil layers on both sides of a glass epoxy base material. After water washing, acid washing, and water washing, the substrate was dried in an air stream.

[0149] (Method for producing laminate 2 - preparation of resist pattern) A negative mask having a pattern of line width (L) / space width (S) = 7 μm / 7 μm was placed on the support of the above-mentioned laminate 1, and then, using a projection exposure apparatus (manufactured by Ushio Inc., trade name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source, the photosensitive layer was exposed through the support at an exposure amount (amount of irradiation energy) such that the number of remaining steps after development of a 41-step step tablet would be 14. Two minutes after exposure, laminate 1 was placed in an 80°C box dryer (manufactured by ETAC, trade name "HT220S") and heated for 30 seconds to obtain laminate 2.

[0150] The exposure dose at which the number of remaining steps after development of a 41-step tablet becomes 14 steps was determined by placing a 41-step tablet (manufactured by Resonac Corporation) on the support of the laminate 1, exposing it using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240") using an ultra-high pressure mercury lamp (365 nm) as a light source, and determining in advance the exposure dose at which the number of remaining steps after development becomes 14 steps. Development was carried out by spraying a 1.0 mass % sodium carbonate aqueous solution at 30°C at a spray pressure of 0.18 MPa for twice the minimum development time. The minimum development time was determined by the method described below.

[0151] (Method for producing laminate 3) The photosensitive layer was exposed by peeling off the support from laminate 2. Subsequently, a 1.0 mass % aqueous sodium carbonate solution at 30°C was sprayed at a spray pressure of 0.18 MPa for a time twice the minimum developing time to remove the unexposed portions, thereby obtaining laminate 3 having a resist pattern (exposed portions of the photosensitive layer) with an L / S=7 μm / 7 μm on the substrate.

[0152] The minimum development time was evaluated in advance by the following procedure. First, the laminate 1 was cut into a rectangular shape (12.5 cm × 4.0 cm), and the support was peeled off to obtain a test piece. Next, the unexposed photosensitive layer of the test piece was spray-developed at a pressure of 0.18 MPa using a 1.0 mass % sodium carbonate aqueous solution at 30°C. The shortest time required for complete removal of the unexposed photosensitive layer to be visually confirmed was defined as the minimum development time.

[0153] (Method for manufacturing laminate 4 - preparation of resist pattern) A 41-step step tablet (manufactured by Resonac Co., Ltd.) was placed on the support of laminate 1, and then the photosensitive layer was exposed through the support using a direct imaging exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name: FDi-MP) with a blue-violet laser diode having a wavelength of 405 nm as a light source, using a drawing pattern with line width (L) / space width (S) = 7 μm / 7 μm, at an exposure amount (irradiation energy amount) such that the number of remaining steps after development of the 41-step step tablet was 14. After 2 minutes from the exposure, laminate 1 was placed in an 80 ° C. box dryer (manufactured by ETAC, product name "HT220S") and heated for 30 seconds to obtain laminate 4.

[0154] The exposure dose that results in 14 remaining steps after development of a 41-step step tablet was determined by placing a 41-step step tablet (manufactured by Resonac Co., Ltd.) on the support of laminate 1, exposing it using a direct imaging exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name: FDi-MP) with a blue-violet laser diode having a wavelength of 405 nm as a light source, and determining in advance the exposure dose that results in 14 remaining steps after development. Development was performed by spraying a 1.0% by mass aqueous sodium carbonate solution at 30°C at a spray pressure of 0.18 MPa for twice the minimum development time. The minimum development time was determined using the method described below.

[0155] (Method for producing laminate 5) The photosensitive layer was exposed by peeling off the support from laminate 4. Subsequently, a 1.0 mass % aqueous sodium carbonate solution at 30°C was sprayed at a spray pressure of 0.18 MPa for a time twice the minimum developing time previously evaluated by the procedure described above, and the unexposed portions were removed, thereby obtaining laminate 5 having a resist pattern (exposed portions of the photosensitive layer) with an L / S=7 μm / 7 μm on the substrate.

[0156]

[0157] As shown in Table 2, when the photosensitive elements of Examples 1 and 2 were used, resist patterns with high rectangularity were obtained by both projection exposure with light having a wavelength of 365 nm and direct writing exposure with light having a wavelength of 405 nm. On the other hand, when the photosensitive elements of Comparative Examples 1 and 2 were used, the rectangularity of the resist patterns was reduced compared to when the photosensitive elements of the Examples were used.

[0158] The disclosure of this application is related to the subject matter described in PCT / JP2024 / 019416, filed May 27, 2024, the disclosures of which are incorporated herein by reference.

Claims

1. A photosensitive element comprising a support and a photosensitive layer disposed on the support, wherein the absorbance of the photosensitive layer at a wavelength of 365 nm is 0.0160 or less per 1 μm of thickness of the photosensitive layer.

2. The photosensitive element of claim 1, wherein the photosensitive layer has an absorbance of 0.0120 or more at 365 nm wavelength per 1 μm of photosensitive layer thickness.

3. The photosensitive element of claim 1, wherein the photosensitive layer has an absorbance of 0.0120 or more at 405 nm wavelength per 1 μm of photosensitive layer thickness.

4. The photosensitive element of claim 1, wherein the photosensitive layer has a thickness in the range of 5 to 40 μm.

5. The photosensitive element according to claim 1, wherein the photosensitive layer is formed from a photosensitive resin composition containing a binder resin, a photopolymerizable compound, a polymerization initiator, a photosensitizer, and a polymerization inhibitor.

6. The photosensitive element of claim 5, wherein the photosensitizer is an anthracene compound.

7. The photosensitive element of claim 6, wherein the polymerization inhibitor is a phenolic compound.

8. A method for producing a laminate, comprising: placing a photosensitive layer of the photosensitive element according to any one of claims 1 to 7 on a substrate; photocuring a portion of the photosensitive layer; and removing the uncured portion of the photosensitive layer to form a resist pattern.

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