Laminate, pattern formation method, cured product, and electronic component

Abstract

To provide a laminate that allows formation of a high-reflectivity solder resist film at high resolution.SOLUTION: A laminate comprises: a first film having an average transmittance of 70% or less in the wavelength range of 400 nm or more and 500 nm or less; and a photosensitive resin layer which is disposed on the first film, contains a white pigment, and has an average reflectance of 50% or more in the wavelength range of 400 nm or more and 500 nm or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a laminate, a pattern forming method, a cured product, and an electronic component. [Background technology]

[0002] There is known a light emitting device in which light emitting diodes (hereinafter sometimes abbreviated as LED) are mounted on a printed wiring board. In order to efficiently utilize the light from the mounted LED, a solder resist with high reflectivity may be formed on the printed wiring board. The formation of the solder resist may require high precision.

[0003] In relation to the above, for example, Patent Document 1 proposes a photosensitive dry film capable of improving molding accuracy, and Patent Document 2 proposes a dry film photoresist film capable of achieving high resolution of the resist. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-071914 A [Patent Document 2] JP 2004-109421 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a highly reflective solder resist is formed using a dry film in which a photosensitive resin layer is formed on a support film, the high reflectance of the photosensitive resin layer may cause a decrease in resolution during exposure. Thus, an object of the present invention is to provide a laminate capable of forming a cured product with high reflectance and high resolution. [Means for solving the problem]

[0006] The present invention includes the following aspects. [1] A first film having an average transmittance of 70% or less in a wavelength range of 400 nm or more and 500 nm or less; a photosensitive resin layer disposed on the first film, the photosensitive resin layer containing a white pigment and having an average reflectance of 50% or more in the wavelength range of 400 nm or more and 500 nm or less.

[0007] [2] The laminate according to [1], wherein the first film has an average thickness of 20 μm or more and 50 μm or less.

[0008] [3] The laminate according to [1] or [2], wherein the photosensitive resin layer has an average thickness of 5 μm or more and 100 μm or less.

[0009] [4] The laminate according to any one of [1] to [3], wherein the content of the white pigment in the photosensitive resin layer relative to the total solid content of the photosensitive resin layer is 9 mass% or more and 95 mass% or less.

[0010] [5] The laminate according to any one of [1] to [4], wherein the ratio of the average transmittance in the wavelength range of 400 nm or more and 500 nm or less to the transmittance at 360 nm is 0.9 or more and 1.5 or less.

[0011] [6] The laminate according to any one of [1] to [5], wherein the photosensitive resin layer has a ratio of an average reflectance in a wavelength range of 400 nm or more and 500 nm or less to a reflectance at 360 nm of 4.0 or more.

[0012] [7] The laminate according to any one of [1] to [6], wherein the photosensitive resin layer further contains a thermosetting resin.

[0013] [8] The laminate according to any one of [1] to [7], further comprising a second film disposed on the side of the photosensitive resin layer opposite the first film.

[0014] [9] laminating the laminate according to any one of [1] to [7] onto a substrate with the photosensitive resin layer facing the substrate; exposing the photosensitive resin layer through the first film of the laminate; removing the first film, and forming a pattern including a cured product of the photosensitive resin layer on the substrate.

[0015]

[10] A cured product contained in a pattern formed by the pattern forming method described in [9].

[0016]

[11] An electronic component comprising the cured product according to

[10] . Effect of the Invention

[0017] According to one aspect of the present invention, a laminate capable of forming a cured product with high reflectance and high resolution can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. Furthermore, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified, when multiple substances corresponding to each component are present in the composition. Furthermore, the upper and lower limits of the numerical ranges described in this specification can be arbitrarily selected and combined. Hereinafter, the embodiments of the present invention will be described in detail. However, the embodiments shown below are examples of a laminate, a pattern forming method, a cured product, and an electronic component for embodying the technical idea of ​​the present invention, and the present invention is not limited to the laminate, the pattern forming method, the cured product, and the electronic component shown below.

[0019] Laminate The laminate comprises a first film (also referred to as a support film) having an average transmittance of 70% or less in a wavelength range of 400 nm or more and 500 nm or less, and a photosensitive resin layer disposed on the first film. The photosensitive resin layer contains a white pigment and has an average reflectance of 50% or more in a wavelength range of 400 nm or more and 500 nm or less. The laminate may be a dry film capable of forming a solder resist having high reflectance by exposing and developing the photosensitive resin layer disposed on a substrate.

[0020] When a photosensitive resin layer capable of forming a solder resist with high reflectance is placed on a substrate and exposed through a first film placed on the photosensitive resin layer, the light reflected from the photosensitive resin layer may be reflected again by the first film and harden the photosensitive resin layer except for the exposed portion, resulting in failure to obtain high resolution. Although the required resolution can be achieved by removing the first film before exposure, removing the first film before exposure entails process risks such as the inclusion of impurities, the surface roughness of the photosensitive resin layer accompanying the removal of the first film, and the difficulty of removal. In the laminate of this embodiment, the average transmittance of the first film in the wavelength range of 400 nm to 500 nm is 70% or less, so that the re-reflection of light reflected from the photosensitive resin layer during exposure can be effectively suppressed. This allows high resolution to be achieved even when exposure is performed through the first film.

[0021] The first film may have an average transmittance of 70% or less in the wavelength range of 400 nm to 500 nm. The average transmittance of the first film in the wavelength range of 400 nm to 500 nm may be preferably 65% ​​or less, 60% or less, or 55% or less, and may be 10% or more, 20% or more, 40% or more, or 45% or more. The average transmittance of the first film in the wavelength range of 400 nm to 500 nm may be 10% or more and 70% or less, and preferably 40% or more and 60% or less. When the average transmittance of the first film is within the above range, higher sensitivity and resolution tend to be obtained. The method of adjusting the average transmittance of the first film is not particularly limited, but examples thereof include a method of appropriately adjusting the type of resin constituting the first film, the type and content of the colorant, and a method of adjusting the average thickness of the first film. Here, the average transmittance in the wavelength range of 400 nm to 500 nm is calculated as the arithmetic mean value of the transmittance measured at 1 nm intervals from 400 nm to 500 nm in the transmission spectrum of the first film measured using an ultraviolet-visible spectrophotometer (UV-VIS). The standard deviation of the transmittance may be, for example, 0.2 or less, preferably 0.1 or less, or 0.05 or more. When the standard deviation of the transmittance is within the above range, a higher resolution tends to be achieved.

[0022] The first film may have a transmittance ratio, which is the ratio of the average transmittance in the wavelength range of 400 nm to 500 nm to the transmittance at 360 nm, of, for example, 0.9 to 1.5. The transmittance ratio may be preferably 1.05 or more, more preferably 1.07 or more, and even more preferably 1.1 or more. The transmittance ratio may be preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.15 or less. When the transmittance ratio is within the above range, higher resolution and sensitivity tend to be achieved.

[0023] The average thickness of the first film may be, for example, 15 μm or more and 70 μm or less. It may be preferably 20 μm or more or 40 μm or less. When the average thickness of the first film is 15 μm or more, the handleability of the laminate tends to be excellent. Also, when it is 70 μm or less, the photosensitivity tends to be good. The average thickness of the first film is calculated as the arithmetic average value of the thicknesses measured at any 10 points on the first film using a micrometer.

[0024] The first film may contain, for example, a resin and a colorant. By containing the colorant, the average transmittance can be easily adjusted to a desired range. In addition, it becomes possible to easily identify the main surface on which the photosensitive resin layer is disposed in the laminate.

[0025] The resin constituting the first film may be a light-transmitting resin generally used for optical applications. Specific examples include poly(alkyl(meth)acrylate), polyethylene, polypropylene, polystyrene, polycarbonate, aromatic or aliphatic polyamide, polyester, polyimide, and the like. The resin constituting the first film may preferably contain at least polyester, and may be a resin mainly composed of polyester. Here, "mainly composed of polyester" means that the content of polyester in the resin is 50% by mass or more, preferably 80% by mass or more.

[0026] Polyester is a resin obtained by condensation polymerization of a monomer composition whose main components are dicarboxylic acid and diol. Here, "mainly" means that the total content of dicarboxylic acid and diol is 50 mol % or more.

[0027] The dicarboxylic acid may be an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfonedicarboxylic acid. Examples of aliphatic dicarboxylic acids include adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. Examples of dicarboxylic acids preferably include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. These dicarboxylic acids may be used alone or in combination of two or more, and further, oxyacids such as hydroxybenzoic acid may be used in part.

[0028] Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, and 2,2-bis(4-hydroxyethoxyphenyl)propane. Ethylene glycol is preferably used as the diol. These diols may be used alone or in combination of two or more.

[0029] As the polyester, preferably, polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene naphthalate and its copolymer, polybutylene terephthalate and its copolymer, polybutylene naphthalate and its copolymer, polyhexamethylene terephthalate and its copolymer, polyhexamethylene naphthalate and its copolymer, etc. can be mentioned, and preferably, at least polyethylene terephthalate may be included. These polyesters may be used as a single polymer, or may be used as a copolymer or a blend within a range that does not impair the effects of the present invention. The resin constituting the first film may be obtained by transfer or may be produced by a known production method.

[0030] As the colorant constituting the first film, organic or inorganic pigments and dyes can be used alone or in combination of two or more. Among these, black pigments are preferred from the viewpoint of adjusting the transmittance. Examples of black pigments include carbon black, naphthalene black, perylene black, iron oxide, manganese dioxide, aniline black, activated carbon, etc. Specific examples of the pigments include carbon black pigments such as CI Pigment black 6, 7, 9, and 18, graphite pigments such as CI Pigment black 8 and 10, iron oxide pigments such as CI Pigment black 11, 12, 27, and Pigment Brown 35; for example, iron oxide KN-370 manufactured by Toda Kogyo Co., Ltd., titanium black 13M-T manufactured by Mitsubishi Materials Corporation, anthraquinone pigments such as CI Pigment black 20, cobalt oxide pigments such as CI Pigment black 13, 25, and 29, copper oxide pigments such as CI Pigment black 15 and 28, manganese pigments such as CI Pigment black 14 and 26, antimony oxide pigments such as CI Pigment black 23, nickel oxide pigments such as CI Pigment black 30, perylene pigments such as CI Pigment black 31 and 32, and Lumogen Black FK4280 manufactured by BASF Japan Ltd., and Pigment Black Examples of suitable pigments include the aniline pigments of 1, molybdenum sulfide, and bismuth sulfide. From the viewpoint of adjusting the transmittance in a desired wavelength range, carbon black pigments are preferred.

[0031] Also, instead of the black pigment, a pigment or dye such as red, blue, green, or yellow can be mixed to produce a black or nearly black colorant. Red colorants include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. Blue colorants include phthalocyanine and anthraquinone. Green colorants include phthalocyanine, anthraquinone, and perylene. Yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone.

[0032] Specific examples of red colorants include monoazo red colorants such as Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269, disazo red colorants such as Pigment Red 37, 38, 41, Pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:1, 52:2, 53: Monoazo lake-based red colorants such as 1, 53:2, 57:1, 58:4, 63:1, 63:2, 64:1, 68, etc.; benzimidazolone-based red colorants such as Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208, etc.; Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red Perylene-based red colorants such as d179, Pigment Red 190, Pigment Red 194, and Pigment Red 224; diketopyrrolopyrrole-based red colorants such as Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, and Pigment Red 272; Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, and Pigment Red 22 1, Pigment Red 242 and other condensed azo-based red colorants; Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207 and other anthraquinone-based red colorants; Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209 and other quinacridone-based red colorants.

[0033] Specific examples of blue colorants include Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:2, Pigment Blue 15:3, Pigment Blue 15:4, Pigment Blue 15:6, Pigment Blue 16, and Pigment Blue 60. Examples of dye-based pigments include Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Solvent Blue 122, Solvent Blue 136, Solvent Blue 67, and Solvent Blue 70. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

[0034] Specific examples of green colorants include Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, and Solvent Green 28. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

[0035] Specific examples of yellow colorants include anthraquinone-based yellow colorants such as Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, and Pigment Yellow 202; isoindolinone-based yellow colorants such as Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, and Pigment Yellow 185; Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, and Pigment Yellow 179; 80, etc.; benzimidazolone yellow colorants such as Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, and Pigment Yellow 181, etc.; Examples of yellow colorants include monoazo yellow colorants such as Pigment Yellow 62:1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, and 183, and disazo yellow colorants such as Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, and 198.

[0036] The content of the colorant in the first film may be adjusted according to the type of the colorant so as to obtain a desired transmittance. For example, when carbon black is used as the colorant, the content of the colorant in the first film may be, for example, 0.1% by mass or more and 60% by mass or less, preferably 0.5% by mass or more or 50% by mass or less, based on the resin.

[0037] The first film may be composed of a resin film containing a colorant in a dispersed state in the resin. The resin film containing a colorant in a dispersed state in the resin may be prepared by receiving or the like, or may be prepared by manufacturing in a conventional manner. The first film can be manufactured, for example, by kneading and dispersing the colorant in the resin constituting the first film, and forming the resin in which the colorant is dispersed into a film shape.

[0038] The first film may be configured by disposing a colored layer containing a colorant on at least one main surface of the resin film serving as the base material. The colored layer contains at least a colorant, and may contain other components such as a binder resin and a filler to the extent that the properties of the colored layer are not impaired. When the first film has a colored layer, the colored layer may be provided only on one main surface of the resin film serving as the base material, or may be provided on both main surfaces. Preferably, the colored layer may be provided at least on the main surface on which the photosensitive resin layer is disposed. Furthermore, the resin film serving as the base material on which the colored layer is provided may further contain a colorant in the resin.

[0039] The surface of the first film on which the photosensitive resin layer is to be formed may be subjected to a release treatment. The release treatment can be performed, for example, by applying a coating liquid prepared by dissolving or dispersing a release agent such as wax, silicone wax, or silicone-based resin in an appropriate solvent to the surface of the first film by a known means such as a coating method such as roll coating or spray coating, gravure printing, or screen printing, and drying the coating liquid.

[0040] The photosensitive resin layer is disposed on one of the main surfaces of the first film to form a laminate. The photosensitive resin layer is composed of a photosensitive resin composition containing a white pigment and a photosensitive resin. The average reflectance of the photosensitive resin layer in the wavelength range of 400 nm to 500 nm may be, for example, 50% or more, and preferably 70% or more, 80% or more, or 85% or more. The average reflectance may be, for example, less than 100% or 99% or less. The average reflectance of the photosensitive resin layer in the wavelength range of 400 nm to 500 nm may be 50% or more and less than 100%, and preferably 80% or more and 99% or less. The average reflectance of the photosensitive resin layer in the wavelength range of 400 nm to 500 nm is calculated as the arithmetic average value of the reflectance measured at 1 nm intervals from 400 nm to 500 nm in the reflection spectrum of the photosensitive resin layer. The photosensitive resin layer may have an average reflectance of, for example, 85% or more, preferably 70% or more, or 80% or more, in the wavelength range of 430 nm to 630 nm. The standard deviation of the reflectance in the wavelength range of 430 nm to 630 nm may be, for example, 1.0 or less, preferably 0.7 or less, or 0.1 or more. The reflectance of the photosensitive resin layer is measured in a reflection mode including regular reflection light using a colorimeter (e.g., CM-5 manufactured by Konica Minolta, Inc.) in the uncured photosensitive resin layer.

[0041] The photosensitive resin layer may have a reflectance ratio, which is the ratio of the average reflectance in a wavelength range of 400 nm or more and 500 nm or less to the reflectance at 360 nm, of, for example, 4 or more. The reflectance ratio may be preferably 6 or more, more preferably 9 or more. The reflectance ratio may be, for example, 20 or less, or 15 or less. Furthermore, the reflectance ratio may be 4 or more and 20 or less, preferably 9 or more and 20 or less.

[0042] The reflectance of the photosensitive resin layer can be adjusted by appropriately selecting, for example, the thickness of the photosensitive resin layer, the type of white pigment, the content of the white pigment, and the like.

[0043] The average thickness of the photosensitive resin layer may be, for example, 5 μm or more and 100 μm or less. In one embodiment, the average thickness may be preferably 15 μm or more, or 20 μm or more. The average thickness may be preferably 80 μm or less, or 30 μm or more. The average thickness of the photosensitive resin layer is calculated by measuring the thickness at any 10 points in the laminate using a micrometer, and subtracting the average thickness of the first film from the average thickness of the laminate calculated as the arithmetic average value.

[0044] The laminate may have a thickness ratio, which is the ratio of the average thickness of the photosensitive resin layer to the average thickness of the first film, of, for example, 0.1 to 4.0, preferably 0.25 to 2.0. When the thickness ratio is within the above range, the handleability tends to be further improved.

[0045] Examples of the white pigment contained in the photosensitive resin layer include titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, talc, mica, aluminum hydroxide, calcium silicate, aluminum silicate, hollow resin particles, zinc sulfide, etc. Among them, titanium oxide is preferred due to its high coloring property and reflectance. These white pigments may be used alone or in combination of two or more kinds.

[0046] Titanium oxide may be produced by the sulfuric acid method, the chlorine method, or the like, or may be rutile-type titanium oxide, anatase-type titanium oxide, or titanium oxide that has been surface-treated with a hydrous metal oxide or an organic compound. Among these titanium oxides, rutile-type titanium oxide is preferred from the viewpoint of forming a stable photosensitive resin layer. As rutile-type titanium oxide, known rutile-type titanium oxides may be used. Specifically, TR-600, TR-700, TR-750, and TR-840 manufactured by Fuji Titanium Industry Co., Ltd., Typepaque R-550, R-580, R-630, R-820, CR-50, CR-58, CR-60, and CR-90 manufactured by Ishihara Sangyo Kaisha, Ltd., and KR-270, KR-310, and KR-380 manufactured by Titanium Industry Co., Ltd. may be used. Titanium oxide may be used alone or in combination of two or more types.

[0047] The particle size of titanium oxide is not particularly limited, but from the viewpoints of resolution, reflectance, and insulation reliability, the average particle size is preferably in the range of 10 nm to 1 μm. In this specification, the average particle size refers to the value of the cumulative average particle size 50% (D50) when the particle size distribution is created on a volume basis, and can be determined by a laser diffraction particle size distribution measuring device or a measuring device using a dynamic light scattering method. An example of a measuring device using the laser diffraction method is Microtrac MT3300EXII manufactured by Microtrac-Bell Co., Ltd., and an example of a measuring device using the dynamic light scattering method is Nanotrac Wave II UT151 manufactured by Microtrac-Bell Co., Ltd.

[0048] The content of the white pigment in the photosensitive resin layer may be appropriately adjusted to an amount that can obtain a desired reflectance. The content of the white pigment in the photosensitive resin layer may be, for example, 9% by mass or more and 95% by mass or less, preferably 10% by mass or more, 20% by mass or more, 40% by mass or more, 55% by mass or more, or 60% by mass or more, and preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, or 75% by mass or less, based on the total solid content of the photosensitive resin layer.

[0049] The photosensitive resin layer may contain a carboxyl group-containing resin as a photosensitive resin. By containing a carboxyl group-containing resin, the photosensitive resin layer can be made alkaline developable. From the viewpoint of photocurability, the carboxyl group-containing resin preferably has an ethylenically unsaturated double bond in the molecule in addition to a carboxyl group. The photosensitive resin layer may also contain a carboxyl group-containing resin that does not have an ethylenically unsaturated double bond and a photopolymerizable compound. The photopolymerizable compound may be a compound having an ethylenically unsaturated double bond, which may be a compound derived from (meth)acrylic acid or a derivative thereof.

[0050] Specific examples of the carboxyl group-containing resin include the following compounds (which may be either oligomers or polymers): In this specification, (meth)acrylate is a general term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

[0051] (1) Carboxy group-containing resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, isobutylene, etc.

[0052] (2) Carboxy group-containing urethane resins obtained by the polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxy group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxy groups and alcoholic hydroxy groups.

[0053] (3) Carboxy group-containing urethane resins obtained by polyaddition reaction of diisocyanates with partially acid anhydride-modified products of reaction products of bifunctional epoxy resins such as bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bixylenol type epoxy resins and biphenol type epoxy resins with monocarboxylic acid compounds having ethylenically unsaturated double bonds such as (meth)acrylic acid, carboxy group-containing dialcohol compounds and diol compounds.

[0054] (4) A carboxyl group-containing urethane resin obtained by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, during the synthesis of the resin (2) or (3) described above, to obtain a terminal (meth)acrylated carboxyl group-containing urethane resin.

[0055] (5) A carboxyl group-containing urethane resin having a terminal (meth)acrylation formed by adding a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reactant of isophorone diisocyanate and pentaerythritol triacrylate, during the synthesis of the resin (2) or (3).

[0056] (6) A carboxyl group-containing resin obtained by reacting a difunctional or more polyfunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl group present in the side chain.

[0057] (7) A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with the hydroxyl groups of a difunctional epoxy resin further epoxidized with epichlorohydrin, with (meth)acrylic acid, and adding a dibasic acid anhydride to the resulting hydroxyl groups.

[0058] (8) Carboxy group-containing polyester resins obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid with a bifunctional oxetane resin and then adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting primary hydroxyl groups.

[0059] (9) A carboxyl group-containing resin obtained by reacting an epoxy compound having a plurality of epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and an unsaturated group-containing monocarboxylic acid, such as (meth)acrylic acid, and then reacting the alcoholic hydroxyl group of the resulting reaction product with a polybasic acid anhydride, such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid.

[0060] (10) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0061] (11) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0062] (12) A carboxyl group-containing resin obtained by adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to any one of the resins (1) to (11) above.

[0063] The acid value of the carboxyl group-containing resin may be, for example, 5 mgKOH / g or more and 150 mgKOH / g or less. When the acid value of the carboxyl group-containing resin is 5 mgKOH / g or more, the developability is further improved. When the acid value is 150 mgKOH / g or less, the resolution is further improved. The acid value of the carboxyl group-containing resin may be preferably 10 mgKOH / g or more and 130 mgKOH / g or less. The acid value of the carboxyl group-containing resin is a value measured in accordance with JIS K5601-1-2-1:1999.

[0064] The weight average molecular weight of the carboxyl group-containing resin may vary depending on the resin skeleton, and may be, for example, 2,000 or more and 150,000 or less. If the weight average molecular weight is 2,000 or more, the touch dryness and resolution of the coating film can be further improved. If the weight average molecular weight is 150,000 or less, the developability and storage stability can be further improved. The weight average molecular weight of the carboxyl group-containing resin may be preferably 5,000 or more and 100,000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

[0065] As the carboxyl group-containing resin, a carboxyl group-containing urethane resin containing any one of (2) to (5) among the above can be preferably used. By including a carboxyl group-containing urethane resin, the dispersibility and reflectance of the photosensitive resin composition and the insulation reliability of the cured product can be further improved, and the adhesion of the cured product to the substrate and the warping of the substrate caused by providing the cured product can be reduced. In particular, as the carboxyl group-containing urethane resin, a carboxyl group-containing urethane resin without an aromatic ring is preferable.

[0066] As the carboxyl group-containing urethane resin without aromatic ring, a carboxyl group-containing urethane resin obtained by reacting (a) an aliphatic compound having two or more isocyanate groups in one molecule, (b) a carboxyl group-containing aliphatic dialcohol, (c) an aliphatic diol having two or more alcoholic hydroxyl groups in one molecule and no carboxyl group, and (d) a monohydroxy (meth) acrylate compound is preferable. Specific examples of the compounds (a) to (d) are shown below, but the compounds (a) to (d) are not limited to the following exemplary compounds. In addition, each of the compounds (a) to (d) may be used alone or in combination of two or more.

[0067] (a) Examples of aliphatic compounds having two or more isocyanate groups in one molecule include isophorone diisocyanate, hexamethylene diisocyanate, cyclohexane-1,3-dimethylene diisocyanate, and cyclohexane-1,4-dimethylene diisocyanate.

[0068] (b) Examples of the carboxyl group-containing aliphatic diol include dimethylolpropionic acid and dimethylolbutanoic acid.

[0069] (c) As the aliphatic diol having two or more alcoholic hydroxy groups and no carboxy group in one molecule, a polycarbonate diol containing a repeating unit derived from an aliphatic diol as a constituent unit is preferable, and examples thereof include a polycarbonate diol derived from 1,6-hexanediol, a polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol, a polycarbonate diol derived from 1,4-butanediol and 1,6-hexanediol, and a polycarbonate diol derived from 3-methyl-1,5-pentanediol and 1,6-hexanediol.

[0070] (d) The monohydroxy(meth)acrylate compound serves as an end-capping agent during the polymerization reaction for polyurethane formation, and examples thereof include hydroxymethyl(meth)acrylate, hydroxyethyl(meth)acrylate, and hydroxybutyl(meth)acrylate.

[0071] The carboxyl group-containing urethane resin may be contained in an amount of, for example, 5 parts by mass or more and 95 parts by mass or less, preferably 40 parts by mass or more and 95 parts by mass or less, more preferably 50 parts by mass or more and 90 parts by mass or less, and even more preferably 50 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the total amount of the carboxyl group-containing resin. When the content of the carboxyl group-containing urethane resin is 40 parts by mass or more relative to 100 parts by mass of the total amount of the carboxyl group-containing resin, the adhesion and low warpage of the cured product are further improved. On the other hand, when the content of the carboxyl group-containing urethane resin is 80 parts by mass or less relative to 100 parts by mass of the total amount of the carboxyl group-containing resin, the reflectance and resolution are further improved.

[0072] In addition, when the carboxyl group-containing resin contains any of the carboxyl group-containing urethane resins (2) to (5) described above, any of the carboxyl group-containing resins (1) and (6) to (12) described above may be used in combination as another carboxyl group-containing resin. In particular, it is preferable to use at least one of the carboxyl group-containing resins (1) and (12) in combination. For example, a carboxyl group-containing photosensitive resin obtained by reacting a carboxyl group-containing (meth)acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule, a carboxyl group-containing resin having a styrene-derived skeleton and no urethane bond obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with a styrene skeleton-containing compound selected from styrene, α-methylstyrene, etc., and the like can be preferably used. By using a carboxyl group-containing urethane resin in combination with a carboxyl group-containing resin having a styrene-derived skeleton and no urethane bond, the dispersibility and reflectance of the curable resin composition are further improved, and the adhesion and low warpage of the cured product are also further improved.

[0073] The carboxyl group-containing resin having a styrene-derived skeleton and no urethane bond (hereinafter also referred to as "styrene-based carboxyl group-containing resin") may be, for example, a resin having a styrene-derived skeleton and a carboxyl group in the molecule, and no photosensitive group such as an ethylenically unsaturated bond. The styrene-based carboxyl group-containing resin can be synthesized by copolymerization using styrene as an essential monomer. Specific examples of the styrene-based carboxyl group-containing resin include a carboxyl group-containing resin (which may be either an oligomer or a polymer) obtained by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid, styrene or α-methylstyrene, and an ethylenically unsaturated group-containing compound selected from lower alkyl (meth)acrylate, isobutylene, and the like. The lower alkyl refers to an alkyl group having 1 to 5 carbon atoms.

[0074] The weight average molecular weight of the styrene-based carboxyl group-containing resin may vary depending on the resin skeleton, and may be, for example, 10,000 or more and 50,000 or less. When the weight average molecular weight is 10,000 or more, the anti-droop effect is better and the dryness to the touch (tack-free performance) is better. Furthermore, the moisture resistance of the cured resin layer after exposure is better, and the film loss during development can be more effectively suppressed. Furthermore, the decrease in resolution can be more effectively suppressed. Furthermore, when the weight average molecular weight is 50,000 or less, in addition to the anti-droop effect, the developability is good and the storage stability is also excellent. The weight average molecular weight may be preferably 10,000 or more and 25,000 or less, more preferably 10,000 or more and 15,000 or less.

[0075] The acid value of the styrene-based carboxyl group-containing resin may be, for example, 80 mgKOH / g or more and 200 mgKOH / g or less. The acid value may be preferably 100 mgKOH / g or more and 160 mgKOH / g or less. When the acid value of the styrene-based carboxyl group-containing resin is 80 mgKOH / g or more, it has a high softening point, is very excellent in tack-free performance, and tends to be excellent in developability. When the acid value is 200 mgKOH / g or less, the crosslink density becomes appropriate, and stress does not occur during curing, and a better cured product tends to be obtained.

[0076] When the photosensitive resin layer contains a styrene-based carboxyl group-containing resin, the styrene-based carboxyl group-containing resin has a styrene-derived skeleton, and thus, despite having an aromatic ring, it unexpectedly suppresses the decrease in reflectance of the cured product due to light irradiation and heat, and also suppresses discoloration, while providing excellent developability and dryness to the touch. The proportion of the styrene-derived skeleton in the styrene-based carboxyl group-containing resin may be, for example, 10 mol% or more and 80 mol% or less in the molecule, preferably 10 mol% or more and 60 mol% or less, more preferably 10 mol% or more and 50 mol% or less. Here, the proportion of the styrene skeleton means the proportion of the styrene monomer to the total amount of monomers during the synthesis of the styrene-based carboxyl group-containing resin. When the proportion of the styrene-derived skeleton in the styrene-based carboxyl group-containing resin is 10 mol% or more, the compatibility with other components is better. Also, when it is 80 mol% or less, the developability is better.

[0077] The styrene-based carboxyl group-containing resin tends to be a high molecular weight resin when produced by suspension polymerization. As a result, the photosensitive resin composition containing the resin has excellent touch dryness (tack-free performance). The weight average molecular weight of the styrene-based carboxyl group-containing resin may be preferably 10,000 or more and 50,000 or less, taking into consideration characteristics such as touch dryness and developability. Therefore, from the viewpoint of controlling the molecular weight, it is preferable to use a chain transfer agent when synthesizing the styrene-based carboxyl group-containing resin. As the chain transfer agent, a known and commonly used one can be used. Specific examples of the chain transfer agent include MSD (α-methylstyrene dimer), n-DM (n-dodecyl mercaptan), and the like.

[0078] A polymerization initiator may be used when synthesizing the styrene-based carboxyl group-containing resin. The polymerization can be promoted by using the polymerization initiator. Examples of the polymerization initiator include BPO (benzoyl peroxide), t-butylperoxy-2-ethylhexanoate, and AMBN (2,2'-azobis(2-methylbutyronitrile)). Among them, AMBN (2,2'-azobis(2-methylbutyronitrile)) is preferable. The amount of the polymerization initiator used may be, for example, 0.1 parts by mass or more and 10 parts by mass or less, and preferably 0.1 parts by mass or more and 4 parts by mass or less, based on 100 parts by mass of the resin, calculated as the solid content during the synthesis of the styrene-based carboxyl group-containing resin.

[0079] When the photosensitive resin layer contains a styrene-based carboxy group-containing resin, the mass ratio of the carboxy group-containing urethane resin to the styrene-based carboxy group-containing resin (carboxy group-containing urethane resin:styrene-based carboxy group-containing resin) may be, for example, 95:5 to 5:95, preferably 90:10 to 10:90. By being in such a range, the dispersibility of the photosensitive resin composition and the insulation reliability of the cured product are further improved. In addition, the mass ratio of the carboxy group-containing urethane resin to the styrene-based carboxy group-containing resin may more preferably be 55:45 to 85:15, more preferably 60:40 to 80:20. By being in such a range, the dispersibility of the photosensitive resin composition, the resolution of the cured product, the reflectance, the insulation reliability, the adhesion, and the low warpage can all be improved in a well-balanced manner.

[0080] The content of the carboxyl group-containing resin may be, for example, 3% by mass or more and 60% by mass or less, preferably 3% by mass or more and 55% by mass or less, calculated as the solid content in the photosensitive resin layer. If the content is 3% by mass or more, the strength of the cured product is further improved. If the content is 60% by mass or less, the viscosity becomes appropriate and the adhesion of the photosensitive resin layer is further improved.

[0081] The photosensitive resin layer may further contain a photopolymerizable compound. The photopolymerizable compound may be a compound having an ethylenically unsaturated double bond. The photopolymerizable compound may be a known and commonly used photopolymerizable polymer, photopolymerizable oligomer, photopolymerizable monomer, or a mixture thereof. Since the photopolymerizable compound has an ethylenically unsaturated double bond, it helps to make the cured resin layer cured by irradiation with active energy rays insoluble in an alkaline aqueous solution.

[0082] Examples of the photopolymerizable oligomer include unsaturated polyester oligomers, (meth)acrylate oligomers, etc. Examples of the (meth)acrylate oligomer include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolac epoxy (meth)acrylate, and bisphenol type epoxy (meth)acrylate, urethane (meth)acrylate, epoxy urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and polybutadiene modified (meth)acrylate. Examples of the photopolymerizable monomer include alkyl (meth)acrylates such as 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; mono- or di(meth)acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, trimethylolpropane, triethyl ... Examples of the photopolymerizable compound include polyhydric (meth)acrylates derived from polyhydric alcohols such as trishydroxyethyl isocyanurate or their ethylene oxide or propylene oxide adducts; (meth)acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth)acrylate and polyethoxy di(meth)acrylate of bisphenol A; (meth)acrylates derived from glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)acrylate. The photopolymerizable compound may be used alone or in combination of two or more.

[0083] The content of the photopolymerizable compound in the photosensitive resin layer may be, for example, 5 parts by mass or more and 100 parts by mass or less, and preferably 5 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the total amount of the carboxyl group-containing resin. If the content is within the above range, the resolution and the strength of the cured product can be further improved.

[0084] The photosensitive resin layer may further contain a photopolymerization initiator. The photopolymerization initiator is not particularly limited, and any known and commonly used photopolymerization initiator may be used.

[0085] Examples of the photopolymerization initiator include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. bisacylphosphine oxides such as bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, and pivaloylphenylphosphinic acid isopropyl ester. , 2,4,6-trimethylbenzoyldiphenylphosphine oxide and other monoacylphosphine oxides; acylphosphinates such as ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; 1-hydroxy-cyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy- hydroxyacetophenones such as hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone;Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl)]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropyl Thioxanthones such as thioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoic acid ethyl ester; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, and 1-(O-acetyloxime); bis(η); 5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1H-pyrrol-1-yl)ethyl)phenyl]titanium, and other titanocenes; phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like can be mentioned. The photopolymerization initiator may be used alone or in combination of two or more kinds. Among the above, it is preferable to include at least one of bisacylphosphine oxides, monoacylphosphine oxides, acylphosphinates, and the like.

[0086] The content of the photopolymerization initiator in the photosensitive resin layer may be, for example, 1 part by mass or more and 30 parts by mass or less, and preferably 2 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of the total amount of the carboxyl group-containing resin. If the content is within the above range, the curing property of the photosensitive resin layer is improved, and the resolution is further improved.

[0087] The photosensitive resin layer may further contain a thermosetting resin. Examples of the thermosetting resin include known and commonly used ones such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy resins, oxetane compounds, and episulfide resins. Among these, the preferred thermosetting resin is the epoxy resin.

[0088] Specific examples of epoxy resins include bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, novolac type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, N-glycidyl type epoxy resins, bisphenol A novolac type epoxy resins, bixylenol type epoxy resins, biphenol type epoxy resins, chelate type epoxy resins, glyoxal type epoxy resins, amino group-containing epoxy resins, rubber-modified epoxy resins, dicyclopentadiene phenolic type epoxy resins, diglycidyl phthalate resins, heterocyclic epoxy resins, tetraglycidyl xylenoyl ethane resins, silicone-modified epoxy resins, ε-caprolactone-modified epoxy resins, etc. Thermosetting resins may be used alone or in combination of two or more types.

[0089] The content of the thermosetting resin in the photosensitive resin layer may be, for example, 5 parts by mass to 150 parts by mass, preferably 10 parts by mass to 80 parts by mass, relative to 100 parts by mass of the total amount of the carboxyl group-containing resin. If the content is within the above range, the solder heat resistance of the cured product will be better, and various properties, particularly insulation reliability, will also be better when used as a solder resist for a printed wiring board.

[0090] When the photosensitive resin layer contains a thermosetting resin, it may further contain a thermosetting catalyst. By containing a thermosetting catalyst, the thermosetting reaction can be accelerated, and properties such as adhesion, chemical resistance, and heat resistance can be further improved. Examples of such a thermosetting catalyst include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Other commercially available compounds include, for example, 2E4MZ, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ (all trade names of imidazole-based compounds) manufactured by Shikoku Chemical Industry Co., Ltd., and U-CAT (registered trademark) 3503N and U-CAT3502T (all trade names of dimethylamine blocked isocyanate compounds), DBU, DBN, U-CATSA102, and U-CAT5002 (all bicyclic amidine compounds and salts thereof) manufactured by San-Apro Co., Ltd. Also usable are s-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-2,4-diamino-s-triazine, 2-vinyl-4,6-diamino-s-triazine·isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-s-triazine·isocyanuric acid adduct, and preferably, these compounds that also function as adhesion-imparting agents may be used in combination with the heat curing catalyst. The heat curing catalyst may be used alone or in combination of two or more.

[0091] The content of the thermosetting catalyst in the photosensitive resin layer may be, for example, 0.1 to 20 parts by mass, preferably 0.5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the thermosetting resin.

[0092] The photosensitive resin layer can be formed by applying a photosensitive resin composition containing the above-mentioned components onto the first film. The photosensitive resin composition forming the photosensitive resin layer may contain an organic solvent. By including an organic solvent, the above-mentioned components can be uniformly dissolved or dispersed, and the viscosity can be adjusted to be suitable for application. Examples of organic solvents include toluene, xylene, ethylbenzene, nitrobenzene, cyclohexane, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, carbitol acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl ethyl ketone, cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, chloroform, methylene chloride, etc. The content of the organic solvent in the photosensitive resin composition can be appropriately set according to the desired viscosity.

[0093] The photosensitive resin layer may further contain an antioxidant. In many polymeric materials, once oxidation begins, oxidation degradation occurs in a chain reaction, which may result in a decrease in the functionality of the polymeric material. By containing an antioxidant, the oxidation of the polymeric material can be suppressed. Examples of the antioxidant include a radical scavenger that neutralizes the generated radicals, and a peroxide decomposer that decomposes the generated peroxides into harmless substances and prevents new radicals from being generated.

[0094] Examples of antioxidants that act as radical scavengers include phenolic compounds such as hydroquinone, 4-t-butylcatechol, 2-t-butylhydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis(4-methyl-6-t-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and 1,3,5-tris(3',5'-di-t-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione; quinone compounds such as methaquinone and benzoquinone; and amine compounds such as bis(2,2,6,6-tetramethyl-4-piperidyl)-sebacate and phenothiazine.

[0095] The radical scavenger may be a commercially available product, and examples thereof include ADK STAB (registered trademark) AO-30, ADK STAB AO-330, ADK STAB AO-20, ADK STAB LA-77, ADK STAB LA-57, ADK STAB LA-67, ADK STAB LA-68, ADK STAB LA-87 (all manufactured by ADEKA CORPORATION), Irganox (registered trademark) 1010, Irganox 1035, Irganox 1076, Irganox 1135, Tinuvin (registered trademark) 111FDL, Tinuvin 123, Tinuvin 144, Tinuvin 152, Tinuvin 292, Tinuvin 5100 (all manufactured by BASF Japan Ltd.).

[0096] Examples of antioxidants that act as peroxide decomposers include phosphorus compounds such as triphenyl phosphite, and sulfur compounds such as pentaerythritol tetralauryl thiopropionate, dilauryl thiodipropionate, and distearyl 3,3'-thiodipropionate. The peroxide decomposer may be commercially available, and examples include Adeka STAB TPP (manufactured by ADEKA CORPORATION), Adeka STAB AO-412S (manufactured by ADEKA CORPORATION), and Sumilizer (registered trademark) TPS (manufactured by Sumitomo Chemical Co., Ltd.). The antioxidants may be used alone or in combination of two or more. The antioxidants may be used alone or in combination of two or more.

[0097] The content of the antioxidant in the photosensitive resin layer may be, for example, 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the carboxy group-containing resin.

[0098] The photosensitive resin layer may further contain additives other than the above components, so long as they do not impair the effects of the present invention. Examples of additives include known inorganic fillers, organic fillers such as silicon powder, nylon powder, and fluorine powder, known and commonly used thickeners such as fine silica, organic bentonite, and montmorillonite, compounds having polar groups such as carboxyl groups, hydroxyl groups, and acid esters, copolymers containing acid groups, wetting and dispersing agents such as hydroxyl group-containing polycarboxylates, silicone-based, fluorine-based, and polymer-based defoamers and / or leveling agents, and fiber reinforcements such as glass fibers, carbon fibers, and boron nitride fibers. In addition, known and commonly used adhesion promoters, ultraviolet absorbers, polymerization inhibitors, silane coupling agents such as imidazole-based, thiazole-based, and triazole-based, plasticizers, foaming agents, flame retardants, antistatic agents, antiaging agents, antibacterial and antifungal agents, etc. may be included as necessary.

[0099] The photosensitive resin composition is obtained by dissolving or dispersing each of the above-mentioned components using a mixer, such as a disperser, kneader, three-roll mill, bead mill, etc. The obtained photosensitive resin composition is applied onto the first film, and at least a part of the organic solvent is removed as necessary to form a photosensitive resin layer, thereby preparing a laminate. The photosensitive resin layer can be formed by applying the photosensitive resin composition to a substantially uniform thickness using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, etc., and drying. The drying conditions may be typically 1 minute to 30 minutes at a temperature of 50°C to 130°C. There is no particular restriction on the coating film thickness, but it is generally appropriately selected, for example, in the range of 1 μm to 150 μm, preferably 5 μm to 100 μm, in terms of the film thickness after drying.

[0100] The laminate may further include a second film on the side of the photosensitive resin layer opposite to the first film. By including the second film, it is possible to prevent dust and the like from adhering to the surface of the photosensitive resin layer and to improve the handling property.

[0101] As the second film (also called a protective film), for example, a polyester film, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, etc. can be used. It is preferable to select a material for the second film such that the adhesive strength between the second film and the photosensitive resin layer is smaller than the adhesive strength between the first film and the photosensitive resin layer. In addition, in order to make it easier to peel off the second film when using the laminate, a release treatment may be applied to the surface of the second film that contacts the photosensitive resin layer.

[0102] The thickness of the second film is not particularly limited, but is appropriately selected depending on the application within the range of about 10 μm to 150 μm.

[0103] Pattern Formation Method The above-mentioned laminate can be used to form a pattern of a cured product on a substrate. The pattern forming method includes laminating the laminate on the substrate with the photosensitive resin layer facing the substrate, exposing the photosensitive resin layer through the first film of the laminate, removing the first film and developing to form a pattern including a cured resin layer on the substrate, and curing the patterned cured resin layer by light irradiation or heat to form a cured product.

[0104] As substrates, in addition to printed wiring boards with pre-formed circuits, flexible printed wiring boards, paper-phenolic resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven cloth-epoxy resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, copper-clad laminates of all grades (such as FR-4) made from composite materials such as fluororesin, polyethylene, PPO, cyanate ester, etc., polyimide film, PET film, glass substrates, ceramic substrates, wafer plates, etc. can be used.

[0105] A pattern forming method using a laminate having a second film will be described. First, i) the second film is peeled off from the laminate to expose the photosensitive resin layer, ii) the photosensitive resin layer of the laminate is placed on the substrate so as to face the substrate, iii) exposure is performed from the first film of the laminate, iv) the first film is removed and development is performed to form a patterned cured resin layer on the substrate, and v) the patterned cured resin layer is further cured by light irradiation or heat to form a cured product. As a result of the above, a patterned cured product is formed on the substrate.

[0106] The photosensitive resin layer of the laminate is laminated on the substrate by any method as long as the substrate and the photosensitive resin layer of the laminate are in close contact with each other. However, it is preferable to use a vacuum laminator or the like to laminate the layers under pressure and heat. By using such a vacuum laminator, the photosensitive resin composition layer is in close contact with the circuit board, so that no air bubbles are mixed in and the hole filling ability on the substrate surface is improved. The pressure condition is preferably 0.1 MPa or more and about 2.0 MPa, and the heating condition is preferably 40°C or more and 120°C or less.

[0107] Exposure (irradiation with active energy rays) is performed from above the first film of the laminate. This process cures only the exposed photosensitive resin layer. The exposure process is not particularly limited, and for example, it may be selectively exposed to active energy rays through a photomask having a desired pattern formed thereon by a contact (or non-contact) method, or a desired pattern may be exposed to active energy rays by a direct imaging device.

[0108] The exposure machine used for irradiating active energy rays may be any device equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or the like, which irradiates ultraviolet rays in the range of 350 nm to 450 nm, and further, a direct imaging device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) may also be used. The laser light source of the direct imaging device may be either a gas laser or a solid-state laser, so long as it uses laser light with a maximum wavelength in the range of 350 nm to 410 nm. The exposure dose for forming an image varies depending on the film thickness, etc., but is generally 20 mJ / cm. 2 More than 800mJ / cm 2 , preferably 20 mJ / cm 2 More than 600mJ / cm 2 The exposure light may be parallel light or scattered light, but scattered light is preferable.

[0109] After the exposure, the first film is peeled off and development is performed to form a patterned cured resin layer on the substrate. The development process is not particularly limited, and a dipping method, a shower method, a spray method, a brush method, etc. can be used. In addition, as the developer, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, or amines can be used.

[0110] The patterned cured resin layer is then cured by irradiation with active energy rays (light) or heat to form a cured product. This process is called main curing or additional curing, and promotes polymerization of unreacted monomers in the exposed cured resin layer, and furthermore, the amount of remaining carboxy groups can be reduced by thermally curing the carboxyl group-containing photosensitive resin and the thermosetting resin (e.g., epoxy resin). The active energy ray irradiation can be performed in the same manner as the above-mentioned exposure, but it is preferable to perform it under conditions of stronger irradiation energy than that during exposure. For example, 500 mJ / cm 2 More than 3000mJ / cm 2 The heat curing can be performed under heating conditions of 100°C to 200°C for about 20 to 90 minutes. It is preferable that the main curing is performed by photocuring followed by heat curing. By performing photocuring first, the flow of the resin is suppressed even during heat curing.

[0111] In the pattern forming method, since the first film has a predetermined average transmittance, a pattern can be formed with excellent resolution even when exposed through the first film. The resolution of the formed pattern may be, for example, 75% or more, preferably 80% or more, or 90% or more, as an aperture ratio at which a rectangular pattern of, for example, 400 μm×300 μm is formed without collapse or rattling.

[0112] cured product The cured product is included in the pattern formed by the above-mentioned pattern forming method. The cured product may be a cured product of the photosensitive resin layer. The cured product shows high reflectance by containing a white pigment. The reflectance of the cured product may be equivalent to that of the uncured photosensitive resin layer. The reflectance of the cured product may be, for example, 50% or more, preferably 70% or more, or 80% or more, as an average reflectance in a wavelength range of, for example, 400 nm or more and 500 nm or less. The average reflectance may be, for example, less than 100%, or 99% or less.

[0113] The present invention may include an electronic component having a cured product as one embodiment. Here, the electronic component means a component used in an electronic circuit, and includes active components such as printed wiring boards, particularly flexible printed wiring boards, transistors, light-emitting diodes, and laser diodes, as well as passive components such as resistors, capacitors, inductors, and connectors, and the cured product of the photosensitive resin layer is suitable as a solder resist for these components.

[0114] Other aspects of the present invention include use of the laminate (dry film) in a pattern formation method for forming a pattern including a cured product of a photosensitive resin layer on a substrate, the laminate (dry film) used in the pattern formation method, use of the laminate (dry film) in the production of a cured product included in the pattern formed by the pattern formation method, the laminate (dry film) used in the production of a cured product included in the pattern formed by the pattern formation method, use of the laminate (dry film) in the production of an electronic component including the cured product, and the laminate (dry film) used in the production of an electronic component including the cured product. EXAMPLES

[0115] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0116] [Synthesis Example 1] Preparation of Carboxy Group-Containing Resin Solution Varnish 1 Into a reaction vessel equipped with a stirrer, a thermometer, and a condenser, 2400g (3 mol) of polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol as diols (TJ5650J, manufactured by Asahi Kasei Corporation, number average molecular weight 800), 603g (4.5 mol) of dimethylolpropionic acid, and 238g (2.6 mol) of 2-hydroxyethyl acrylate as a monohydroxy compound were added. Next, 1887g (8.5 mol) of isophorone diisocyanate was added as a polyisocyanate, and the mixture was heated to 60°C while stirring and stopped. When the temperature in the reaction vessel started to drop, the mixture was heated again and continued stirring at 80°C. The reaction was terminated when it was confirmed that the absorption spectrum (2280cm-1) of the isocyanate group had disappeared in the infrared absorption spectrum, and the solid content concentration was adjusted by adding carbitol acetate to obtain a photosensitive carboxyl group-containing urethane resin solution. The resulting carboxyl group-containing urethane resin solution (varnish 1) had a solid content acid value of 50 mgKOH / g, a solid content of 50%, and a weight average molecular weight Mw of 17,000. The weight average molecular weight was measured by high performance liquid chromatography using a pump LC-6AD manufactured by Shimadzu Corporation and three columns Shodex (registered trademark) KF-804, KF-803, and KF-802 manufactured by Resonac Corporation.

[0117] [Synthesis Example 2] Preparation of Carboxy Group-Containing Resin Solution Varnish 2 377g of tripropylene glycol monomethyl ether was placed in a 2,000ml flask equipped with a stirrer and a cooling tube, and heated to 90°C under a nitrogen stream. A mixture of 104.2g of styrene, 246.5g of methacrylic acid, and 20.7g of dimethyl 2,2'-azobis(2-methylpropionate) (Fujifilm Wako Pure Chemical Industries, Ltd.: V-601) was added dropwise to the flask over 4 hours. In this way, a carboxyl group-containing resin solution having a styrene-derived skeleton and no urethane bond was obtained. The obtained carboxyl group-containing resin solution (varnish 2) had a solid acid value of 120mgKOH / g, a solid content of 50%, and a weight average molecular weight Mw=20,000. The weight average molecular weight was measured in the same manner as above.

[0118] Preparation of photosensitive resin composition Using the above-mentioned varnish as the carboxyl group-containing resin, various components shown in Table 1 were blended in the indicated ratios (parts by mass), premixed with a stirrer, and then kneaded with a three-roll mill to prepare photosensitive resin compositions 1 to 3. Values ​​in Table 1 are solid contents and parts by mass unless otherwise specified.

[0119] [Table 1]

[0120] In addition, ingredients *1 to *9 in Table 1 are as follows. *1: Wetting and dispersing agent (Disperbyk-111, manufactured by BYK) *2: Defoaming and leveling agent (BYK-1791, manufactured by BYK) *3: Bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad 819, IGM Resins) *4: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation) *5: Antioxidant (IRGANOX1010, manufactured by BASF Japan Ltd.) *6: Heat curing catalyst (manufactured by Nissan Chemical Co., Ltd.) *7: Titanium oxide (Tipake CR-58, average particle size: 0.28 μm, manufactured by Ishihara Sangyo Kaisha, Ltd.) *8: Phenol novolac type epoxy resin (diethylene glycol monoethyl ether acetate diluted solution, solid content 75% by mass, manufactured by DIC Corporation) *9: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)

[0121] Dispersion stability The dispersion stability of the photosensitive resin composition obtained above was evaluated in accordance with JIS K5600-2-5:1999. Specifically, about 2 g of the photosensitive resin composition was placed on the surface of a grind gauge with a length of 175 mm, a width of 65 mm, a thickness of 19 mm, and a maximum depth of 50 μm, and scraped at a uniform speed to a groove depth of 0 for 1 to 2 seconds using a scraper with a length of 90 mm, a width of 40 mm, a thickness of 6 mm, and a long side of the blade tip with a rounded diameter of 0.25 mm. The groove was observed 3 seconds after the scraping was completed, and the groove depth of the part where the particle size was 5 or more in total was confirmed, and the dispersibility was evaluated according to the following evaluation criteria. The results are shown in Table 1.

[0122] Evaluation criteria A: Less than 30 μm B: 30μm or more and less than 50μm C:50μm or more

[0123] First film preparation As the first film, the following films 1 to 8 were prepared. The average transmittance in the wavelength range of 400 nm or more and 500 nm or less and the transmittance at 360 nm of the prepared films were measured by the method described later. Film 1: A PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm × 150 mm × average thickness of 25 μm was used as film 1. Film 2: Film 2 was prepared by coating one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm x 150 mm x average thickness of 25 μm with a carbon black dispersion liquid so as to give an average transmittance of 5%. Film 3: Film 3 was prepared by coating one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm×average thickness of 25 μm with a carbon black dispersion liquid so that the average transmittance became 10%. Film 4: Film 4 was prepared by applying a carbon black dispersion liquid to one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm×average thickness of 25 μm so that the average transmittance became 30%. Film 5: Film 5 was prepared by applying a carbon black dispersion liquid to one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm×average thickness of 25 μm so that the average transmittance became 50%. Film 6: Film 6 was prepared by coating one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm×average thickness of 25 μm with a carbon black dispersion liquid so that the average transmittance became 70%. Film 7: Film 7 was prepared by applying a carbon black dispersion liquid to one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm×average thickness of 25 μm so that the average transmittance became 75%. Film 8: A carbon black dispersion was kneaded into PET (polyethylene terephthalate) resin and molded into a 150 mm×150 mm film having a thickness of 25 μm and an average transmittance of 50%.

[0124] Transmittance of the first film The average transmittance of the first film described above was measured as follows. Films 1 to 8 were cut into 20 mm x 20 mm samples for measurement, and the transmittance was measured at 1 nm intervals in the wavelength range of 400 nm to 500 nm using an ultraviolet-visible spectrophotometer (UV-VIS V570, manufactured by JASCO Corporation). The average of the measured transmittances was calculated to obtain the average transmittance. The calculation results are shown in Table 2. Similarly, the transmittance was measured at a wavelength of 360 nm, and the measurement results are shown in Table 2.

[0125] Average thickness of the first film The average thickness of the first film described above was measured as follows. A PET film was cut into a size of 150 mm x 150 mm to serve as a measurement sample, and the thickness was measured at any 10 points (locations) using a micrometer (Coolant Proof, manufactured by Mitutoyo Corporation). The arithmetic average of the measured thicknesses was calculated to obtain the average thickness. The average thickness of each of the prepared first films was 25 μm.

[0126] Preparation of laminate (dry film) Any of the photosensitive resin compositions 1 to 3 prepared above was applied onto a first film shown in Table 2 using an applicator and dried at 90° C. for 20 minutes to form a photosensitive resin layer with an average thickness of 45 μm, thereby producing laminates (dry films) of Examples 1 to 8 and Comparative Examples 1 and 2. For the first films obtained by applying a carbon black dispersion, a photosensitive resin layer was formed on the surface to which the carbon black dispersion was applied.

[0127] The average thickness of the photosensitive resin layer was calculated by subtracting the average thickness of the first film used in each laminate (dry film) from the average thickness of each laminate (dry film). The average thickness of each laminate (dry film) was measured as follows. Each laminate (dry film) was used as a measurement sample, and the thickness of each laminate was measured at any 10 points (locations) using a micrometer (Mitutoyo Corporation, Coolant Proof). The arithmetic average of the measured thicknesses of each laminate was calculated to be the average thickness.

[0128] evaluation The laminate obtained above was evaluated for average reflectance at 400 nm or more and 500 nm or less, reflectance at 360 nm, sensitivity, and resolution as follows. The evaluation results are shown in Table 2.

[0129] average reflectance The photosensitive resin layer of each laminate obtained above was attached to a soda lime glass substrate measuring 160 mm in length, 110 mm in width, and 1.8 mm in thickness so that the photosensitive resin layer of each laminate was in contact with the substrate. Next, a two-chamber vacuum laminator (Nikko Materials Co., Ltd., CVP-300) was used to laminate the laminate to the glass substrate under the conditions of the first chamber being 80°C in temperature, 0.4 MPa in pressure, and 30 seconds in time, and the second chamber being 80°C in temperature, 0.78 MPa in pressure, and 60 seconds in time, and the first film was peeled off from each laminate to obtain a sample for measuring reflectance. Each sample for measuring reflectance was measured with a colorimeter (Konica Minolta, Inc., CM-5) using reflected light. The measurement conditions and method are shown below.

[0130] Measurement conditions Software: CM-S100w "SpectraMagic NX" Reflection measurement: SCI Measurement diameter: Φ8mm

[0131] Zero calibration was performed by covering the plate with the included zero calibration box CM-A124, and then white calibration was performed using the built-in white calibration plate. After that, light was incident on the photosensitive resin layer side of each laminate obtained above, and the reflectance in the wavelength range of 400 nm to 500 nm was measured every 1 nm, and the arithmetic average of the measured values ​​was calculated to obtain the average reflectance. The results are shown in Table 2.

[0132] Reflectance at 360 nm The reflectance of the photosensitive resin layer at 360 nm was measured in the same manner as above. The results are shown in Table 2.

[0133] sensitivity The laminates prepared by the above method were attached to a soda lime glass substrate measuring 160 mm in length, 110 mm in width, and 1.8 mm in thickness so that the photosensitive resin layers of each laminate were in contact with each other. Next, using a two-chamber vacuum laminator (Nikko Materials Co., Ltd., CVP-300), the glass substrate and the laminate were laminated under the following conditions in the first chamber: temperature 80°C, pressure 0.4 MPa, time 30 seconds, and in the second chamber: temperature 80°C, pressure 0.78 MPa, time 60 seconds. An exposure device equipped with a high-pressure mercury lamp (short arc lamp) was used to laminate the laminates to an integrated exposure dose of 900 mJ / cm. 2 A 41-step step tablet was placed on the first film and exposed from the first film side so that the step number was 1. The first film of the laminate was then peeled off and developed with a 1% by weight aqueous solution of sodium carbonate at 30°C for 90 seconds, after which the number of steps of the remaining step tablet was read and evaluated according to the following criteria. The evaluation results are shown in Table 2.

[0134] Evaluation criteria A: 15 or more remaining step tablets B: The number of remaining step tablets is 10 to 14 C: The number of remaining step tablets is 5 to 9 D: Less than 5 remaining step tablets

[0135] Resolution The laminates prepared by the above-mentioned method were laminated to a soda lime glass substrate measuring 160 mm in length, 110 mm in width, and 1.8 mm in thickness so that the photosensitive resin layers of each laminate were in contact with each other. Then, using a two-chamber vacuum laminator (Nikko Materials Co., Ltd., CVP-300), the first chamber conditions were 80°C temperature, 0.4 MPa pressure, and 30 seconds, and the second chamber conditions were 80°C temperature, 8 kgf / cm pressure. 2 The laminate was laminated onto a glass substrate for 60 seconds, and the cumulative exposure was 900 mJ / cm 2 using a direct imaging exposure machine (light source: high-pressure mercury lamp). 2 A rectangular pattern of 400 μm×300 μm was exposed from the first film side so that the result was as follows. After that, the first film of the laminate was peeled off, and the laminate was developed with 1% by mass sodium carbonate at 30° C. for 90 seconds. The area of ​​the rectangular pattern formed by removing the uncured photosensitive resin layer was taken as the area of ​​the opening, and the opening ratio was calculated by the following formula, and the resolution was evaluated according to the following criteria. The evaluation results are shown in Table 2.

[0136]

number

[0137] Evaluation criteria A: Opening rate is 90% or more B: Opening rate is 80% or more but less than 90% C: Opening rate is 70% or more but less than 80% D: Opening rate is more than 1% and less than 70% E: Opening rate is less than 1%

[0138] [Table 2]

[0139] From Table 2, it can be seen that when the average reflectance of the photosensitive resin layer in the wavelength range of 400 nm or more and 500 nm or less is 50% or more, by setting the average transmittance of the first film in the wavelength range of 400 nm or more and 500 nm or less to 70% or less, excellent resolution is exhibited even when exposed through the first film.

Claims

1. A first film having an average transmittance of 70% or less in a wavelength range of 400 nm or more and 500 nm or less; a photosensitive resin layer disposed on the first film, the photosensitive resin layer containing a white pigment and having an average reflectance of 50% or more in a wavelength range of 400 nm or more and 500 nm or less.

2. The laminate according to claim 1 , wherein the first film has an average thickness of 20 μm or more and 50 μm or less.

3. The laminate according to claim 1 , wherein the photosensitive resin layer has an average thickness of 5 μm or more and 100 μm or less.

4. 2 . The laminate according to claim 1 , wherein the photosensitive resin layer has a content of the white pigment of 9% by mass or more and 95% by mass or less relative to a total solid content of the photosensitive resin layer.

5. 2. The laminate according to claim 1, wherein the first film has a ratio of an average transmittance in a wavelength range of 400 nm or more and 500 nm or less to a transmittance at 360 nm of 0.9 or more and 1.5 or less.

6. 2. The laminate according to claim 1, wherein the photosensitive resin layer has a ratio of an average reflectance in a wavelength range of 400 nm or more and 500 nm or less to a reflectance at 360 nm of 4.0 or more.

7. The laminate according to claim 1 , wherein the photosensitive resin layer further contains a thermosetting resin.

8. The laminate according to claim 1 , further comprising a second film disposed on the surface of the photosensitive resin layer opposite to the first film.

9. laminating the laminate according to claim 1 onto a substrate with the photosensitive resin layer facing the substrate; exposing the photosensitive resin layer through the first film of the laminate; removing the first film, and forming a pattern including a cured product of the photosensitive resin layer on the substrate.

10. A cured product contained in a pattern formed by the pattern forming method according to claim 9 .

11. An electronic part comprising the cured product according to claim 10.

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