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

Abstract

[Problem] To provide a laminate in which a solder resist film having high reflectivity can be formed with high resolution. [Solution] A laminate provided with: a first film having an average transmittance of 70% or less in a wavelength range of 400-500 nm (inclusive); and a photosensitive resin layer that is disposed on the first film, contains a white pigment, and has an average reflectance of 50% or more in a wavelength range of 400-500 nm (inclusive).

Description

Technical Field

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

[0002] A light emitting device is known in which a light emitting diode (hereinafter sometimes abbreviated as LED) is mounted on a printed wiring board. In order to efficiently utilize the light of the mounted LED, a solder resist with high reflectivity is formed on the printed wiring board. In some cases, high precision is required for the formation of the solder resist.

[0003] In this regard, for example, Japanese Patent Application Laid-Open No. 2007-071914 proposes a photosensitive dry film capable of improving molding accuracy. Japanese Patent Application Laid-Open No. 2004-109421 proposes a dry film photoresist film capable of achieving high resolution of a resist. Summary of the invention

[0004] Problems to be solved by the present invention

[0005] When a high-reflectivity solder resist is formed using a dry film having a photosensitive resin layer formed on a support film, the resolution during exposure may be reduced due to the high reflectivity of the photosensitive resin layer. Therefore, an object of one embodiment of the present invention is to provide a laminate that can form a cured product with high reflectivity and high resolution.

[0006] Means of solving the problem

[0007] The present invention includes the following embodiments.

[0008] [1] A laminate comprising:

[0009] a first film having an average transmittance of 70% or less in a wavelength range of 400 nm to 500 nm; and

[0010] A photosensitive resin layer is disposed on the first film, contains a white pigment, and has an average reflectivity of 50% or more in a wavelength range of 400 nm to 500 nm.

[0011] [2] The laminated body according to [1], wherein the average thickness of the first film is 20 μm or more and 50 μm or less.

[0012] [3] The laminate according to [1] or [2], wherein the average thickness of the photosensitive resin layer is 5 μm or more and 100 μm or less.

[0013] [4] The laminate according to any one of [1] to [3], wherein the content of the white pigment in the photosensitive resin layer is 9% by mass or more and 95% by mass or less relative to the total solid content of the photosensitive resin layer.

[0014] [5] The laminate according to any one of [1] to [4], wherein a ratio of an average transmittance of the first film in a wavelength range of 400 nm to 500 nm to a transmittance at 360 nm is 0.9 to 1.5.

[0015] [6] The laminate according to any one of [1] to [5], wherein the ratio of the average reflectivity of the photosensitive resin layer in the wavelength range of 400 nm to 500 nm to the reflectivity at 360 nm is 4.0 or more.

[0016] [7] The laminated body according to any one of [1] to [6], wherein the photosensitive resin layer further contains a thermosetting resin.

[0017] [8] The laminate according to any one of [1] to [7], further comprising:

[0018] A second film is disposed on a surface of the photosensitive resin layer opposite to the first film.

[0019] [9] A pattern forming method comprising the following steps:

[0020] bonding the laminate according to any one of [1] to [7] to the substrate in a manner such that the photosensitive resin layer faces the substrate;

[0021] exposing the photosensitive resin layer via the first film of the laminate;

[0022] The first film is removed to form a pattern on the substrate, wherein the pattern includes a cured product of the photosensitive resin layer.

[0023]

[10] A cured product comprising a pattern formed by the pattern forming method according to [9].

[0024]

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

[10] .

[0025] Effects of the Invention

[0026] According to one embodiment of the present invention, it is possible to provide a laminated body capable of forming a cured product having high reflectivity and high resolution. DETAILED DESCRIPTION

[0027] The term "process" in this specification is not only used to refer to an independent process, but also includes a process that achieves the intended purpose of the process even if it cannot be clearly distinguished from other processes. In addition, the content of each component in the composition, when there are multiple substances equivalent to each component in the composition, refers to the total amount of the multiple substances present in the composition unless otherwise specified. And the upper and lower limits of the numerical ranges recorded in this specification are, and the numerical values ​​can be arbitrarily selected for combination. The following describes the embodiments of the present invention in detail. However, the embodiments shown below are for concretizing the technical ideas of the present invention and illustrating the laminate, pattern forming method, cured product and electronic components, and the present invention is not limited to the laminate, pattern forming method, cured product and electronic components shown below.

[0028] Laminated body

[0029] 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 to 500 nm; 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 to 500 nm. The laminate may be a dry film, and a solder resist having a high reflectivity may be formed by exposing / developing the photosensitive resin layer disposed on the substrate.

[0030] When a photosensitive resin layer capable of forming a solder resist with high reflectivity is arranged on a substrate and exposed through a first film arranged on the photosensitive resin layer, there is a situation where the light reflected from the photosensitive resin layer is re-reflected by the first film and the photosensitive resin layer other than the exposed portion is hardened and high resolution cannot be obtained. Although the desired resolution can be achieved by removing the first film and then exposing, removing the first film before exposure may involve process risks such as the introduction of contaminants, the roughness of the surface of the photosensitive resin layer caused by the removal of the first film, and the difficulty of removal. In the laminate of this embodiment, by making the average transmittance of the first film in the wavelength range of more than 400nm and less than 500nm less than 70%, the re-reflection of light reflected from the photosensitive resin layer during exposure can be effectively suppressed. As a result, high resolution can be achieved even when exposure is performed through the first film.

[0031] Alternatively, the average transmittance of the first film in the wavelength range of 400 nm to 500 nm may be 70% or less. The average transmittance of the first film in the wavelength range of 400 nm to 500 nm may also be preferably 65% ​​or less, 60% or less, or 55% or less, or 10% or more, 20% or more, 40% or more, or 45% or more. In addition, the average transmittance of the first film in the wavelength range of 400 nm to 500 nm may also be 10% or more and 70% or less, or 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. There is no particular limitation on the method for adjusting the average transmittance of the first film, and examples include a method for appropriately adjusting the type of resin constituting the first film, the type and content of the colorant, and a method for 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 of the transmittance measured every 1 nm 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, and may preferably be 0.1 or less, or 0.05 or more. By making the standard deviation of the transmittance within the above range, a higher resolution tends to be achieved.

[0032] The ratio of the average transmittance of the first film in the wavelength range of 400 nm to 500 nm to the transmittance at 360 nm, i.e., the transmittance ratio, may also be, for example, 0.9 to 1.5. The transmittance ratio may also be preferably 1.05 or more, more preferably 1.07 or more, and further preferably 1.1 or more. In addition, the transmittance ratio may also be preferably 1.3 or less, more preferably 1.2 or less, and further preferably 1.15 or less. By making the transmittance ratio within the above range, a higher resolution and sensitivity tend to be achieved.

[0033] The average thickness of the first film may also be, for example, 15 μm or more and 70 μm or less. It may also be preferably 20 μm or more, or 40 μm or less. By making the average thickness of the first film 15 μm or more, the operability of the laminate tends to be better. In addition, by making the thickness 70 μm or less, the photosensitivity tends to be good. The average thickness of the first film is calculated by measuring the thickness at any ten points on the first film using a micrometer as its arithmetic mean.

[0034] The first film may also contain, for example, a resin and a colorant. By containing a colorant, the average transmittance can be easily adjusted to a desired range. In addition, the main surface on which the photosensitive resin layer is arranged in the laminate can be easily identified.

[0035] The resin constituting the first film may also be a light-transmitting resin commonly used for optical purposes. Specifically, for example, poly(meth)alkyl acrylate, polyethylene, polypropylene, polystyrene, polycarbonate, aromatic or aliphatic polyamide, polyester, polyimide, etc. may be cited. The resin constituting the first film may also preferably contain at least polyester, or may be a resin with polyester as the main component. Here, "with polyester as the main component" means that the content of the polyester component in the resin is 50% by mass or more, preferably 80% by mass or more.

[0036] Polyester is a resin obtained by polycondensation of a monomer composition having dicarboxylic acid and diol as main structural components. Here, "mainly" means that the total content of dicarboxylic acid and diol is 50 mol% or more.

[0037] The dicarboxylic acid may be an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid. As aromatic dicarboxylic acids, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, etc. may be cited. As aliphatic dicarboxylic acids, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, etc. may be cited. As dicarboxylic acids, preferably aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid may be cited. These dicarboxylic acids may be used alone or in combination of two or more. In addition, oxygen-containing acids such as hydroxybenzoic acid may be partially used.

[0038] Examples of the diol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, etc. As the diol, ethylene glycol is preferably used. These diols may be used alone or in combination of two or more.

[0039] As polyester, preferably, polyethylene terephthalate, copolymers of ethylene terephthalate and ethylene isophthalate, polyethylene naphthalate and copolymers thereof, polybutylene terephthalate and copolymers thereof, polybutylene naphthalate and copolymers thereof, polyhexamethylene terephthalate and copolymers thereof, polyhexamethylene naphthalate and copolymers thereof, etc. can be listed, preferably, at least polyethylene terephthalate can be included. These polyesters can be used as a single polymer, or can be used in the form of a copolymer or a blend within the scope of not damaging the effect of the present invention. The resin constituting the first film can be obtained by purchase or the like, or can be manufactured by a known manufacturing method.

[0040] As the colorant constituting the first film, one organic or inorganic pigment and dye may be used alone, or two or more may be used in combination. Among them, black pigment is preferred from the viewpoint of adjusting transmittance. Examples of black pigment include carbon black, naphthalene black, perylene black, iron oxide, manganese dioxide, aniline black, activated carbon, and the like. Specifically, for example, suitable 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, iron oxide pigments such as KN-370 iron oxide manufactured by Toda Industries, Ltd., 13M-T titanium black 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, CI Pigment Black 31 and 32, perylene pigments such as Lumogen Black FK4280 manufactured by BASF Japan Ltd., aniline pigments such as Pigment Black 1, molybdenum sulfide, and bismuth sulfide. From the viewpoint of adjusting the transmittance in a desired wavelength range, carbon black pigments are preferred.

[0041] In addition, red, blue, green, yellow and other pigments or dyes can also be mixed to replace black pigments to form black or black-based colorants close to it. As red colorants, monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, quinacridone, etc. can be listed. As blue colorants, phthalocyanine, anthraquinone, etc. can be listed. As green colorants, phthalocyanine, anthraquinone, perylene, etc. can also be listed. As yellow colorants, monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, etc. can be listed.

[0042] Specific examples of red colorants include the following: 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 and other monoazo red colorants, Pigment Red 37, 38, 41 and other disazo red colorants Red colorant, Pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:1, 52:2, 53:1, 53:2, 57:1, 58:4, 63:1, 63:2, 64:1, 68 and other monoazo lake red colorants, Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208 and other benzimidazolone red Colorants, solvent red 135, solvent red 179, pigment red 123, pigment red 149, pigment red 166, pigment red 178, pigment red 179, pigment red 190, pigment red 194, pigment red 224 and other perylene red colorants, pigment red 254, pigment red 255, pigment red 264, pigment red 270, pigment red 272 and other diketopyrrolopyrrole red colorants, pigment red 220, pigment red 144, pigment Condensed azo red colorants such as Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221, Pigment Red 242, anthraquinone red colorants such as Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207, and quinacridone red colorants such as Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, and Pigment Red 209.

[0043] As the blue colorant, specifically, the following substances can be listed: 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, Pigment Blue 60, etc. As the dye system, Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97 can be listed, and examples of solvents include Solvent Blue 122, Solvent Blue 136, Solvent Blue 67, Solvent Blue 70, etc. In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

[0044] 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 may also be used.

[0045] Specific examples of yellow colorants include the following: anthraquinone yellow colorants such as solvent yellow 163, pigment yellow 24, pigment yellow 108, pigment yellow 193, pigment yellow 147, pigment yellow 199, pigment yellow 202, isoindolinone yellow colorants such as pigment yellow 110, pigment yellow 109, pigment yellow 139, pigment yellow 179, pigment yellow 185, condensed azo yellow colorants such as pigment yellow 93, pigment yellow 94, pigment yellow 95, pigment yellow 128, pigment yellow 155, pigment yellow 166, pigment yellow 180, pigment yellow 120, pigment yellow 151, pigment yellow 154, pigment yellow 156, pigment yellow 17 5. Benzimidazolone yellow colorants such as Pigment Yellow 181, monoazo yellow colorants such as Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183, etc., 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, 198, etc.

[0046] The content of the colorant in the first film can be adjusted according to the type of the colorant to obtain a desired transmittance. For example, when carbon black is used as the colorant, the content of the colorant in the first film can be, for example, 0.1% by mass or more and 60% by mass or less relative to the resin, and can also be preferably 0.5% by mass or more, or 50% by mass or less.

[0047] The first film may also 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 purchase or the like, or may be prepared by manufacturing using a conventional method. The first film may be manufactured by kneading and dispersing the colorant in the resin constituting the first film, and molding the resin containing the colorant dispersed into a film shape.

[0048] In addition, the first film may be configured such that a coloring layer containing a colorant is disposed on at least one main surface of a resin film serving as a substrate. The coloring layer contains at least a colorant, and may also contain other components such as a binder resin and a filler within a range that does not impair the characteristics of the coloring layer. In the case where the first film has a coloring layer, the coloring layer may be disposed only on one main surface of the resin film serving as a substrate, or may be disposed on both main surfaces. Preferably, a coloring layer is disposed on at least a main surface on which a photosensitive resin layer is disposed. In addition, the resin film serving as a substrate provided with a coloring layer may further contain a colorant in the resin.

[0049] The surface of the first film provided with the photosensitive resin layer may be subjected to a demolding treatment. The demolding treatment may be carried out, for example, by applying a coating liquid prepared by dissolving or dispersing a demolding agent such as wax, silicone wax, or silicone resin in an appropriate solvent to the surface of the first film by a known method such as a roller coating method, a spraying method, a gravure printing method, or a screen printing method, and drying the coating liquid.

[0050] The photosensitive resin layer is arranged on one main surface of the first film to form a laminate. The photosensitive resin layer is composed of a photosensitive resin composition, which contains a white pigment and a photosensitive resin. The average reflectivity of the photosensitive resin layer in a wavelength range of 400 nm to 500 nm can be, for example, 50% or more, preferably 70% or more, 80% or more, or 85% or more. In addition, the average reflectivity can be, for example, less than 100%, or 99% or less. In addition, the average reflectivity of the photosensitive resin layer in a wavelength range of 400 nm to 500 nm can be 50% or more and less than 100%, preferably 80% or more and 99% or less. The average reflectivity of the photosensitive resin layer in a wavelength range of 400 nm to 500 nm is calculated as the arithmetic mean of the reflectivity measured every 1 nm from 400 nm to 500 nm in the reflection spectrum of the photosensitive resin layer. In addition, the average reflectivity of the photosensitive resin layer in the wavelength range of more than 430nm and less than 630nm can be, for example, more than 85%, preferably more than 70%, or more than 80%. The standard deviation of the reflectivity in the wavelength range of more than 430nm and less than 630nm can be, for example, less than 1.0, preferably less than 0.7, or more than 0.1. In addition, the reflectivity of the photosensitive resin layer is measured in the uncured photosensitive resin layer using a colorimeter (e.g., CM-5 manufactured by Konica Minolta Co., Ltd.) in a reflection mode including regular reflected light.

[0051] The ratio of the average reflectivity of the photosensitive resin layer in the wavelength range of 400 nm to 500 nm to the reflectivity at 360 nm, i.e., the reflectivity ratio, may be, for example, 4 or more. The reflectivity ratio may also be preferably 6 or more, more preferably 9 or more. In addition, the reflectivity ratio may also be, for example, 20 or less, or 15 or less. Furthermore, the reflectivity ratio may also be 4 or more and 20 or less, preferably 9 or more and 20 or less.

[0052] The reflectance of the photosensitive resin layer can be adjusted by, for example, appropriately selecting the thickness of the photosensitive resin layer, the type of white pigment, the content of the white pigment, and the like.

[0053] The average thickness of the photosensitive resin layer may be, for example, 5 μm or more and 100 μm or less. The average thickness in one embodiment may preferably be 15 μm or more, or 20 μm or more. The average thickness may also preferably be 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 ten 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 mean thereof.

[0054] The laminate may have a thickness ratio, which is a 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.

[0055] 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 in view of high coloring property and reflectivity. These white pigments may be used alone or in combination of two or more.

[0056] As titanium oxide, titanium oxide, rutile titanium oxide, anatase titanium oxide, or titanium oxide surface-treated with a hydrated metal oxide or surface-treated with an organic compound, etc., manufactured by a sulfuric acid method, a chlorine method, etc., can be used. Among these titanium oxides, from the viewpoint of forming a stable photosensitive resin layer, rutile titanium oxide is preferred. As rutile titanium oxide, known rutile titanium oxide can be used. Specifically, TR-600, TR-700, TR-750, TR-840 manufactured by Fuji Titanium Industry Co., Ltd., TIPAQUE R-550, R-580, R-630, R-820, CR-50, CR-58, CR-60, CR-90 manufactured by Ishihara Industry Co., Ltd., KR-270, KR-310, KR-380, etc. manufactured by Titanium Industry Co., Ltd. can be used. Titanium oxide can be used alone or in combination of two or more.

[0057] The particle size of titanium oxide is not particularly limited, but from the viewpoint of resolution, reflectivity, and insulation reliability, the average particle size is preferably in the range of 10 nm or more and 1 μm or less. In this specification, the average particle size refers to the value of 50% (D50) of the cumulative average particle size when the particle size distribution is performed based on the volume, which can be obtained using a laser diffraction particle size distribution measuring device or a measuring device using a dynamic light scattering method. As a measuring device using the laser diffraction method, Microtrac MT3300EXII manufactured by Mychik Biotech Co., Ltd. can be listed, and as a measuring device using the dynamic light scattering method, Nanotrac Wave II UT151 manufactured by Mychik Biotech Co., Ltd. can be listed.

[0058] The content of the white pigment in the photosensitive resin layer can be appropriately adjusted to an amount that can obtain the desired reflectivity. Relative to the total solids of the photosensitive resin layer, the content of the white pigment in the photosensitive resin layer can 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 weight or more, 55% by weight or more, or 60% by weight or more, or preferably 90% by weight or less, 85% by weight or less, 80% by weight or less, or 75% by weight or less.

[0059] The photosensitive resin layer may also contain a carboxyl-containing resin as the photosensitive resin. By containing the carboxyl-containing resin, the photosensitive resin layer can be subjected to alkaline development. From the viewpoint of photocurability, the carboxyl-containing resin preferably has an ethylenically unsaturated double bond in the molecule in addition to the carboxyl group. In addition, the photosensitive resin layer may contain a carboxyl-containing resin and a photopolymerizable compound that do not have an ethylenically unsaturated double bond. As the photopolymerizable compound, compounds having an ethylenically unsaturated double bond may be cited, and compounds derived from (meth) acrylic acid or a derivative thereof may also be cited.

[0060] As specific examples of carboxyl-containing resins, the following compounds (which may be any one of oligomers and polymers) may be cited. In addition, in this specification, "(meth)acrylate" is a general term for acrylate, methacrylate and mixtures thereof, and the same is true for other similar expressions.

[0061] (1) Carboxyl group-containing resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with a compound containing an unsaturated group such as styrene, α-methylstyrene, a lower alkyl (meth)acrylate, or isobutylene.

[0062] (2) Carboxyl group-containing polyurethane resins obtained by the addition polymerization of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxyl group-containing diol compounds such as dimethylol propionic acid and dimethylol butyric acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A-based alkylene oxide addition diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0063] (3) A carboxyl-containing polyurethane resin obtained by the addition polymerization of a diisocyanate with a partially anhydride-modified product of a reaction product of a difunctional epoxy resin such as a bisphenol A epoxy resin, a hydrogenated bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol S epoxy resin, a dixylenol epoxy resin, or a bisphenol epoxy resin and a monocarboxylic acid compound having an ethylenically unsaturated double bond such as (meth)acrylic acid, a carboxyl-containing diol compound, and a diol compound.

[0064] (4) A carboxyl-containing polyurethane resin having terminal (meth)acrylate esterification is prepared by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups to a molecule of a hydroxyalkyl (meth)acrylate or the like during the synthesis of the resin of (2) or (3) above.

[0065] (5) In the synthesis process of the resin of (2) or (3) above, a compound having one isocyanate group and one or more (meth)acryloyl groups is added to a molecule of a molar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, etc., to obtain a carboxyl-containing polyurethane resin with terminal (meth)acrylate.

[0066] (6) A carboxyl group-containing resin obtained by reacting a bifunctional or higher-functional epoxy resin with (meth)acrylic acid to add a dibasic acid anhydride to the hydroxyl group present in the side chain.

[0067] (7) A carboxyl-containing resin obtained by reacting a polyfunctional epoxy resin after epoxidizing the hydroxyl groups of a bifunctional epoxy resin with epichlorohydrin with (meth)acrylic acid, and adding a dibasic acid anhydride to the generated carboxyl groups.

[0068] (8) A carboxyl-containing polyester resin obtained by reacting a bifunctional oxetane resin with a dibasic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid, and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the generated primary hydroxyl group.

[0069] (9) A carboxyl-containing resin obtained by reacting an epoxy compound having multiple 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-hydroxyphenylethanol, or a monocarboxylic acid containing an unsaturated group such as (meth)acrylic acid, and reacting the alcoholic hydroxyl group of the resulting reaction product with a polyacid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, or the like.

[0070] (10) A carboxyl group-containing resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide to obtain a reaction product with an unsaturated group-containing monocarboxylic acid and reacting the reaction product with a polybasic acid anhydride.

[0071] (11) A carboxyl group-containing resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to obtain a reaction product with a monocarboxylic acid containing an unsaturated group, and reacting the reaction product with a polybasic acid anhydride.

[0072] (12) A carboxyl group-containing resin obtained by adding a compound having one epoxy group and one or more (meth)acryloyl groups to any one of the resins (1) to (11) above.

[0073] The acid value of the carboxyl-containing resin can be, for example, 5 mgKOH / g or more and 150 mgKOH / g or less. When the acid value of the carboxyl-containing resin is 5 mgKOH / g or more, the developability is further improved. In addition, when the acid value is 150 mgKOH / g or less, the resolution is further improved. The acid value of the carboxyl-containing resin is preferably 10 mgKOH / g or more and 130 mgKOH / g or less. In addition, the acid value of the carboxyl-containing resin is a value measured based on JIS K5601-1-2-1:1999.

[0074] The weight average molecular weight of carboxyl resin can change according to resin backbone, and can be for example more than 2000 and less than 150000.When weight average molecular weight is more than 2000, can further improve the dryness to touch of coating film, resolution etc.In addition, when weight average molecular weight is less than 150000, can further improve developability, storage stability etc.The weight average molecular weight of carboxyl resin can be preferably more than 5000 and less than 100000.In addition, weight average molecular weight can be measured by gel permeation chromatography (GPC).

[0075] As the carboxyl group-containing resin, a carboxyl group-containing polyurethane resin containing any one of the above (2) to (5) can be preferably used. By containing a carboxyl group-containing polyurethane resin, the dispersibility and reflectivity of the photosensitive resin composition and the insulation reliability of the cured product are further improved, and the adhesion of the cured product to the substrate and the warping of the substrate caused by the presence of the cured product can be reduced. In particular, as the carboxyl group-containing polyurethane resin, a carboxyl group-containing polyurethane resin without an aromatic ring is preferred.

[0076] As the carboxyl-containing polyurethane resin without an aromatic ring, it is preferred that the carboxyl-containing polyurethane resin is obtained by reacting (a) an aliphatic compound having two or more isocyanate groups in one molecule, (b) a carboxyl-containing aliphatic diol, (c) an aliphatic diol having two or more alcoholic hydroxyl groups and no carboxyl group in one molecule, and (d) a monohydroxy (meth)acrylate compound. Specific examples of the compounds (a) to (d) are shown below, but the compounds (a) to (d) are not limited to the compounds exemplified below. In addition, the compounds (a) to (d) may be used alone or in combination of two or more.

[0077] (a) Examples of the aliphatic compound having two or more isocyanate groups in one molecule include isophorone diisocyanate, hexamethylene diisocyanate, cyclohexane-1,3-dimethyl diisocyanate, and cyclohexane-1,4-dimethyl diisocyanate.

[0078] (b) Examples of the carboxyl group-containing aliphatic diol include dimethylol propionic acid and dimethylol butyric acid.

[0079] (c) As the aliphatic diol having two or more alcoholic hydroxyl groups and no carboxyl group in one molecule, a polycarbonate diol containing repeating units derived from an aliphatic diol as constituent units is preferred, and examples thereof include polycarbonate diols derived from 1,6-hexanediol, polycarbonate diols derived from 1,5-pentanediol and 1,6-hexanediol, polycarbonate diols derived from 1,4-butanediol and 1,6-hexanediol, polycarbonate diols derived from 1,4-butanediol and 1,6-hexanediol, and polycarbonate diols derived from 3-methyl-1,5-pentanediol and 1,6-hexanediol.

[0080] (d) The monohydroxy (meth)acrylate compound is a terminal sealing agent during the polymerization reaction of urethane formation, and examples thereof include hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, and hydroxybutyl (meth)acrylate.

[0081] Relative to the total amount of 100 mass parts of carboxyl resin, the carboxyl polyurethane resin can be contained in a ratio of 5 mass parts or more and 95 mass parts or less, preferably 40 mass parts or more and 95 mass parts or less, more preferably 50 mass parts or more and 90 mass parts or less, and further preferably 50 mass parts or more and 80 mass parts or less. When the content of the carboxyl polyurethane resin is 40 mass parts or more relative to the total amount of 100 mass parts of the carboxyl resin, the adhesion and low warpage of the cured product are further improved. On the other hand, when the content of the carboxyl polyurethane resin is 80 mass parts or less relative to the total amount of 100 mass parts of the carboxyl resin, the reflectivity and resolution are further improved.

[0082] In addition, when the carboxyl-containing resin contains any one of the carboxyl-containing polyurethane resins in (2) to (5), any one of the carboxyl-containing resins in (1) and (6) to (12) may be used together as other carboxyl-containing resins. It is particularly preferred to use at least one of the carboxyl-containing resins of (1) and (12) together. For example, it is preferred to use a carboxyl-containing photosensitive resin obtained by reacting a carboxyl-containing (meth) acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule, a carboxyl-containing resin having a skeleton derived from styrene and not having a carbamate bond obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with a compound containing a styrene skeleton selected from styrene, α-methylstyrene, etc. By using a carboxyl-containing polyurethane resin and a carboxyl-containing resin having a skeleton derived from styrene and not having a carbamate bond together, the dispersibility and reflectivity of the curable resin composition are further improved, and the adhesion and low warpage of the cured product are also further improved.

[0083] The carboxyl-containing resin having a skeleton derived from styrene and not having a carbamate bond (hereinafter also referred to as "styrene-based carboxyl-containing resin") can be, for example, a resin having a skeleton derived from styrene and a carboxyl group in the molecule and not having photosensitive groups such as ethylenically unsaturated bonds. The styrene-based carboxyl-containing resin can be synthesized by copolymerizing styrene as an essential monomer. As specific examples of styrene-based carboxyl-containing resins, for example, carboxyl-containing resins obtained by copolymerizing unsaturated carboxylic acids such as (meth) acrylic acid, styrene or α-methylstyrene, and ethylenically unsaturated compounds selected from lower (meth) alkyl (meth)acrylates, isobutylene, etc. (can be any of oligomers and polymers). In addition, a lower alkyl group refers to an alkyl group having 1 to 5 carbon atoms.

[0084] The weight average molecular weight of styrene-based carboxyl-containing resin can be different according to the resin backbone, for example, can be more than 10000 and less than 50000. When the weight average molecular weight is more than 10000, the anti-adhesion effect is better, and dryness to touch (non-adhesion performance) is better. Then, the moisture resistance of the cured resin layer after exposure becomes better, and the film can be further suppressed to reduce during development. Further, the reduction of resolution can be more effectively suppressed. In addition, when the weight average molecular weight is less than 50000, in addition to the above-mentioned anti-adhesion effect, developability is good, and storage stability is also more excellent. The weight average molecular weight is preferably more than 10000 and less than 25000, more preferably more than 10000 and less than 15000.

[0085] The acid value of the styrene-based carboxyl-containing resin can be, for example, 80 mgKOH / g or more and 200 mgKOH / g or less. The acid value is preferably 100 mgKOH / g or more and 160 mgKOH / g or less. When the acid value of the styrene-based carboxyl-containing resin is 80 mgKOH / g or more, the softening point tends to be high, the non-tackiness performance is very excellent, and the developability is also very excellent. When the acid value is 200 mgKOH / g or less, the crosslinking density tends to become appropriate, and no stress is generated during curing to obtain a better cured product.

[0086] In the case where the photosensitive resin layer includes a styrene-based carboxyl resin, since the styrene-based carboxyl resin has a skeleton derived from styrene, although it has an aromatic ring, the decrease in reflectivity caused by light irradiation and heat of the cured product is unexpectedly suppressed, and discoloration is suppressed, and the developability and touch dryness are excellent. The proportion of the skeleton derived from styrene in the styrene-based carboxyl resin in the molecule can be, for example, 10 mol% or more and 80 mol% or less, preferably 10 mol% or more and 60 mol% or less, and more preferably 10 mol% or more and 50 mol% or less. Here, the proportion of the styrene skeleton refers to the proportion of the styrene monomer relative to the total amount of monomers when the styrene-based carboxyl resin is synthesized. When the proportion of the skeleton derived from styrene in the styrene-based carboxyl resin is 10 mol% or more, the compatibility with other components becomes better. In addition, when it is 80 mol% or less, the developability becomes better.

[0087] Styrene-based carboxyl-containing resins are manufactured by suspension polymerization and tend to be high molecular weight resins. As a result, the photosensitive resin composition containing the resin has excellent dry-to-touch properties (non-sticky properties). Taking into account properties such as dry-to-touch properties and developability, the weight average molecular weight of the styrene-based carboxyl-containing resin is preferably greater than 10,000 and less than 50,000. Therefore, from the viewpoint of molecular weight control, when synthesizing styrene-based carboxyl-containing resins, it is preferred to use a chain transfer agent. As a chain transfer agent, a well-known and commonly used chain transfer agent can be used. As a chain transfer agent, specifically, MSD (α-methylstyrene dimer), n-DM (n-dodecyl mercaptan), etc. can be listed.

[0088] When synthesizing styrene-based carboxyl-containing resins, polymerization initiators can also be used. The use of polymerization initiators can promote polymerization. As polymerization initiators, BPO (benzoyl peroxide), tert-butyl peroxy-2-ethylhexanoate, AMBN (2,2'-azobis (2-methylbutyronitrile)), etc. can be listed. Among them, AMBN (2,2'-azobis (2-methylbutyronitrile)) is preferred. As a solid content conversion during the synthesis of styrene-based carboxyl-containing resins, the amount of polymerization initiator used can be, for example, 0.1 mass parts or more and 10 mass parts or less, preferably 0.1 mass parts or more and 4 mass parts or less, relative to 100 mass parts of resin.

[0089] When the photosensitive resin layer contains a styrene-based carboxyl-containing resin, the mass ratio of the carboxyl-containing polyurethane resin to the styrene-based carboxyl-containing resin (carboxyl-containing polyurethane resin: styrene-based carboxyl-containing resin) can be, for example, 95:5 to 5:95, preferably 90:10 to 10:90. Within 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 carboxyl-containing polyurethane resin to the styrene-based carboxyl-containing resin is more preferably 55:45 to 85:15, and further preferably 60:40 to 80:20. Within such a range, the dispersibility of the photosensitive resin composition, the resolution, reflectivity, insulation reliability, adhesion, and low warpage of the cured product can all be improved in a balanced manner.

[0090] The containing ratio of carboxyl resin is converted with the solid content in the photosensitive resin layer, for example, can be more than 3 mass % and below 60 mass %, preferably more than 3 mass % and below 55 mass %.When containing ratio is more than 3 mass %, the intensity of cured product further improves.In addition when containing ratio is below 60 mass %, then viscosity is suitable, and the adhesion of photosensitive resin layer further improves.

[0091] The photosensitive resin layer may further contain a photopolymerizable compound. The photopolymerizable compound may be any compound having an ethylenically unsaturated double bond. Examples of the photopolymerizable compound include known and commonly used photopolymerizable polymers, photopolymerizable oligomers, photopolymerizable monomers, and mixtures thereof. Since the photopolymerizable compound has an ethylenically unsaturated double bond, it helps to prevent the cured resin layer cured by active energy ray irradiation from being dissolved in an alkaline aqueous solution.

[0092] 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 epoxy (meth)acrylate, urethane (meth)acrylate, epoxyurethane (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, trihydroxymethylpropane, di ... Polyols such as ethyl isocyanurate or polyols (meth)acrylates derived from ethylene oxide or propylene oxide adducts thereof; (meth)acrylates of phenolic ethylene oxide or propylene oxide adducts such as phenoxyethyl (meth)acrylate and bisphenol A (meth)acrylate polyoxyglycidyl esters; (meth)acrylates derived from glycidyl ethers such as glycerol 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.

[0093] Relative to 100 parts by weight of the total amount of the carboxyl-containing resin, the content of the photopolymerizable compound in the photosensitive resin layer can be, for example, 5 parts by weight or more and 100 parts by weight or less, preferably 5 parts by weight or more and 70 parts by weight or less. If the content is within the above range, the resolution and the strength of the cured product can be further improved.

[0094] The photosensitive resin layer may further contain a photopolymerization initiator. The photopolymerization initiator is not particularly limited, and a known and commonly used photopolymerization initiator can be used.

[0095] 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, bis-(2,6-dimethoxybenzoyl)-2,4-trimethylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis-acylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, bis-(2,6-diphenyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like. Monoacylphosphine oxides such as acylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphonate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; acylphosphonates such as ethyl (2,4,6-trimethylbenzoyl)phenylphosphonate; hydroxyacetophenones such as 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one; benzoin, benzyl, Benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, michelsteine, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-diethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl) methyl]-4-morpholinylphenyl]-4-morpholinylphenyl](4-morpholinylphenyl)]-4--1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoates such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and ethyl p-dimethylbenzoate;1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxy)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(O-acetoximate) and other oxime esters; bis(η5-2,4-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 titanium olefins; phenyl disulfide 2-nitrofluorene, butyne, anisole, azobisisobutyronitrile, tetramethylthiuram disulfide, etc. The photopolymerization initiator can be used alone or in combination of two or more. Among the above substances, it is preferred to contain at least one of bisacylphosphine oxides, monoacylphosphine oxides, acylphosphonates, etc.;

[0096] The content of the photopolymerization initiator in the photosensitive resin layer can be, for example, 1 part by mass or more and 30 parts by mass or less, 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-containing resin. If the content is within the above range, the curability of the photosensitive resin layer is improved, and the resolution is also improved.

[0097] The photosensitive resin layer may further include a thermosetting resin. Examples of the thermosetting resin include isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy resins, oxetane compounds, epithioether resins, and other commonly known resins. Among them, the thermosetting resin is preferably an epoxy resin.

[0098] Specific examples of epoxy resins include bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, brominated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, novolac epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, N-glycidyl epoxy resins, bisphenol A novolac epoxy resins, dioxane epoxy resins, bisphenol epoxy resins, chelate epoxy resins, glyoxal epoxy resins, amino-containing epoxy resins, distyryl-modified epoxy resins, castor phthalate resins, hybrid epoxy resins, tetraglycidyl alkyl silyl ethane resins, silicone-modified epoxy resins, ε-caprolactone-modified epoxy resins, etc. The thermosetting resins may be used alone or in combination of two or more.

[0099] The content of the thermosetting resin in the photosensitive resin layer can be, for example, 5 to 150 parts by mass, preferably 10 to 80 parts by mass, relative to 100 parts by mass of the total amount of the carboxyl-containing resin. If the content is within the above range, the solder heat resistance of the cured product becomes better, and various properties, particularly insulation reliability, when used as a solder resist for a printed circuit board also become better.

[0100] In the case where the photosensitive resin layer includes a thermosetting resin, a thermosetting catalyst may be further included. By including a thermosetting catalyst, the thermosetting reaction can be promoted, and the properties such as adhesion, chemical resistance, and heat resistance can be further improved. As such a thermosetting catalyst, for example, imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide, and phosphorus compounds such as triphenylphosphine can be listed. In addition, commercially available compounds include, for example, 2E4MZ, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ (all trade names of imidazole compounds) manufactured by Shikoku Chemicals Co., Ltd., U-CAT (registered trademark) 3503N and U-CAT3502T (all trade names of blocked isocyanate compounds of dimethylamine) manufactured by San Apro Co., Ltd., DBU, DBN, U-CATSA102, and U-CAT5002 (all trade names of blocked isocyanate compounds of dimethylamine) and bicyclic compounds thereof. In addition, 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, 2,4-diamino-6-methacryloyloxyethyl-s-triazine·isocyanuric acid adduct and other s-triazine derivatives may also be used, and these compounds imparting adhesion may be used in combination for thermal curing. The thermal curing catalyst may be used alone or in combination of two or more.

[0101] The content of the thermosetting catalyst in the photosensitive resin layer may be, for example, 0.1 to 20 parts by mass, and preferably 0.5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the thermosetting resin.

[0102] The photosensitive resin layer can be formed by imparting a photosensitive resin composition containing the above-mentioned components on the first film. The photosensitive resin composition forming the photosensitive resin layer can contain an organic solvent. By including an organic solvent, the above-mentioned components can be uniformly dissolved or dispersed, and can also be adjusted to a viscosity suitable for imparting. As organic solvents, for example, 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, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, ethyl ketone, ethyl ketone, N-dimethylamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, chloroform, dichloromethane, etc. can be cited. The content of the organic solvent in the photosensitive resin composition can be appropriately set according to the desired viscosity.

[0103] The photosensitive resin layer may further include an antioxidant. Once most polymer materials begin to oxidize, oxidation degradation may occur continuously, resulting in reduced functionality of the polymer materials. By including an antioxidant, oxidation of the polymer material may be suppressed. Examples of the antioxidant include free radical scavengers that invalidate generated free radicals, peroxide decomposers that decompose generated peroxides into harmless substances, and peroxide decomposers that do not generate new free radicals.

[0104] Examples of the antioxidant that functions as a free radical scavenger include hydroquinone, 4-tert-butylcatechol, 2-tert-butylhydroquinone, hydroquinone, 2-tert-butylhydroquinone, 2,2-methylene-bis(4-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-5-tert-butylphenyl)butane, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-5-tert-butylphenyl). , phenolic compounds such as 1,3-trityl-5-trityl-5-trimethyl-5-trityl-5-trimethyl-5-trimethyl-5-trimethyl-5-trimethyl-5-trimethyl-5-triphenyl(3',5'-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, quinone compounds such as hydroquinone and benzoquinone, amine compounds such as bis(2,2,6,6-tetramethyl-4-piperidinyl)-acetone and phenothiazine, etc.

[0105] The radical scavenger may be commercially available, 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, and ADK STAB LA-87 (all manufactured by ADK CORPORATION), Irganox (registered trademark) 1010, Irganox 1035, Irganox 1076, Irganox 1135, Tinuvin (registered trademark) 111FDL, Tinuvin 123, Tinuvin 144, Tinuvin 152, Tinuvin 292, and Tinuvin 5100 (all manufactured by BASF Japan Ltd.).

[0106] As antioxidants that act as peroxide decomposers, for example, phosphorus compounds such as triphenyl phosphate, pentaerythritol tetralauryl thiopropionate, dilauryl thiodipropionate, distearyl 3,3'-thiodipropionate and other sulfur compounds can be listed. Peroxide decomposers can also be commercially available, for example, ADKSTAB TPP (manufactured by Aidico Co., Ltd.), ADK STAB AO-412S (manufactured by Aidico Co., Ltd.), Sumilizer (registered trademark) TPS (manufactured by Sumitomo Chemical Co., Ltd.), etc. The antioxidants can be used alone or in combination of two or more. The antioxidants can be used alone or in combination of two or more.

[0107] 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 relative to 100 parts by mass of the carboxyl group-containing resin.

[0108] As long as the effect of the present invention is not damaged, the photosensitive resin layer can also include other additives other than the above-mentioned components. As additives, known conventional tackifiers such as known inorganic fillers, organic fillers such as silicon powder, nylon powder, fluorine powder, micro powder silicon dioxide, organic bentonite, montmorillonite, compounds with polar groups such as carboxyl, hydroxyl, acid esters, copolymers containing acid groups, wetting dispersants such as hydroxyl-containing polycarboxylates, silicone systems, fluorine systems, polymer systems, defoamers and / or leveling agents, fiber reinforced materials such as glass fiber, carbon fiber, boron nitride fibers, etc. can be listed. In addition, as required, known conventional close-fitting promoters, ultraviolet light absorbers, inhibitors, silane coupling agents such as imidazoles, thiazoles, triazoles, plasticizers, foaming agents, flame retardants, antistatic agents, anti-aging agents, antibacterial / mildew-proof agents, etc. can also be included.

[0109] The photosensitive resin composition is obtained by dissolving or dispersing the above-mentioned components using a mixer, such as a disperser, a kneader, a three-roll mill, a bead mill, etc. The obtained photosensitive resin composition is imparted to the first film, and at least a portion of the organic solvent is removed as needed to form a photosensitive resin layer, thereby preparing a laminate. The photosensitive resin layer can be formed by coating the photosensitive resin composition with a substantially uniform thickness and drying it using a comma coater, a blade coater, a lip coater, a rod coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, etc. The drying conditions can generally be 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 the film thickness after general drying is, for example, 1 μm or more and 150 μm or less, preferably appropriately selected in the range of 5 μm or more to 100 μm.

[0110] The laminate may further include a second film disposed on the surface of the photosensitive resin layer opposite to the first film. By including the second film, dust and the like can be prevented from adhering to the surface of the photosensitive resin layer, and the handling property can be improved.

[0111] As the second film (also referred to as 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. The second film is preferably a material whose adhesion to the photosensitive resin layer is smaller than that of the first film to the photosensitive resin layer. In addition, when using a laminate, in order to facilitate the peeling of the second film, a demolding treatment may be applied to the surface of the second film that contacts the photosensitive resin layer.

[0112] The thickness of the second film is not particularly limited and can be appropriately selected in the range of about 10 μm to 150 μm depending on the intended use.

[0113] Patterning method

[0114] The above-mentioned laminate can be used to form a pattern of a cured product on a substrate. The pattern forming method comprises the following steps: bonding the laminate to a substrate in a manner that the photosensitive resin layer faces the substrate; exposing the photosensitive resin layer through a first film of the laminate; developing by removing the first film to form a pattern on the substrate, the pattern including a cured resin layer; curing the patterned cured resin layer by light irradiation or heat to form a cured product.

[0115] As the substrate, in addition to printed wiring boards and flexible printed wiring boards with pre-formed circuits, copper-clad laminates of all grades (FR-4, etc.) using composite materials such as paper-phenolic resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven fabric-epoxy resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, fluororesin / polyethylene / PPO / cyanate ester, polyimide films, PET films, glass substrates, ceramic substrates, chip boards, etc. can also be used.

[0116] A method for forming a pattern using a laminate having a second film is 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 made to face the substrate and bonded to the substrate, iii) exposure is performed from the first film of the laminate, iv) the first film is removed and developed 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. Thus, a patterned cured product is formed on the substrate.

[0117] In order to bond the photosensitive resin layer of the laminate to the substrate, there is no particular limitation as long as the substrate and the photosensitive resin layer of the laminate are in close contact, but it is preferred to use a vacuum laminator or the like to bond under pressure and heating. By using such a vacuum laminator, since the photosensitive resin composition layer is in close contact with the circuit substrate, bubbles are not mixed in, and the pore filling property on the substrate surface is also improved. The pressurization 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.

[0118] Exposure (irradiation with active energy rays) is performed from the first film of the laminate. Through this process, only the photosensitive resin layer after exposure is cured. The exposure process is not particularly limited, and for example, it can be selectively exposed to active energy rays through a photomask formed with a desired pattern by contact (or non-contact method), or it can be exposed to the desired pattern by active energy rays by a direct writing device.

[0119] As an exposure machine for active energy ray irradiation, any device equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, etc., which irradiates ultraviolet rays in the range of 350nm to 450nm, can be used. In addition, a direct writing device (for example, a laser direct writing device that directly draws an image with a laser using CAD data from a computer) can also be used. As the laser light source of the direct writing machine, any laser with a maximum wavelength in the range of 350nm to 410nm, either a gas laser or a solid laser can be used. The exposure amount used for image formation varies depending on the film thickness, etc., but can generally be set to 20mJ / cm 2 Above and 800mJ / cm 2, preferably 20 mJ / cm 2 Above and 600mJ / cm 2 In addition, the exposure may be parallel light or scattered light, but scattered light is preferred.

[0120] After exposure, the first film is peeled off and developed, thereby forming a patterned cured resin layer on the substrate. The development process is not particularly limited, and an immersion method, a spray method, a spray method, a brush method, etc. can be used. In addition, as a developer, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, and amines can be used.

[0121] Next, the patterned cured resin layer is cured by active energy ray (light) irradiation or heat to form a cured product. This process is called formal curing or additional curing, which can promote the polymerization of unreacted monomers in the exposed cured resin layer, and then, the carboxyl-containing photosensitive resin and the thermosetting resin (such as epoxy resin) can be thermally cured to reduce the amount of residual carboxyl groups. Active energy ray irradiation can be carried out in the same way as the above-mentioned exposure, but it is preferably carried out under conditions with stronger irradiation energy than that during exposure. For example, it can be set to 500mJ / cm 2 Above and 3000mJ / cm 2 In addition, thermal curing can be performed under heating conditions of 100°C to 200°C for about 20 minutes to 90 minutes. In addition, the formal curing is preferably performed after the photocuring. By performing the photocuring first, the flow of the resin can be suppressed even during the heat curing.

[0122] 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, for example, an aperture ratio in which a 400 μm×300 μm rectangular pattern is formed without collapse or shaking, can be, for example, 75% or more, preferably 80% or more, or 90% or more.

[0123] Cured material

[0124] 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 a photosensitive resin layer. The cured product shows a high reflectivity due to the inclusion of a white pigment. The reflectivity of the cured product may be the same as that of an uncured photosensitive resin layer. The reflectivity of the cured product may be, for example, an average reflectivity of 50% or more, preferably 70% or more, or 80% or more, in a wavelength range of 400 nm to 500 nm. In addition, the average reflectivity may be, for example, less than 100%, or less than 99%.

[0125] As an embodiment, the present invention may include an electronic component having a cured product. Here, the electronic component refers to a component used in an electronic circuit, including active components such as printed wiring boards, especially flexible printed wiring boards, transistors, light-emitting diodes, laser diodes, etc., as well as passive components such as resistors, capacitors, inductors, connectors, etc., and the cured product of the photosensitive resin layer is suitable as a solder resist for these components.

[0126] As another embodiment, the present invention also includes: the use of the laminate (dry film) in a pattern forming method for forming a pattern of a cured product including a photosensitive resin layer on a substrate, the laminate (dry film) used in the pattern forming method, the use of the laminate (dry film) in the manufacture of a cured product included in a pattern formed by the pattern forming method, the laminate (dry film) used in the manufacture of a cured product included in a pattern formed by the pattern forming method, the use of the laminate (dry film) in the manufacture of an electronic component including the cured product, and the laminate (dry film) used in the manufacture of an electronic component including the cured product.

[0127] [Example]

[0128] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0129] [Synthesis Example 1] Preparation of carboxyl-containing resin solution varnish 1

[0130] In a reaction container equipped with a stirring device, a thermometer, and a capacitor, 2400 g (3 mol) of polycarbonate diol (TJ5650J manufactured by Asahi Kasei Corporation, number average molecular weight 800) derived from 1,5-pentanediol and 1,6-hexanediol as diols, 603 g (4.5 mol) of dimethylol propionic acid, and 238 g (2.6 mol) of 2-hydroxyethyl acrylate as a monohydroxy compound were added. Next, 1887 g (8.5 mol) of isophorone diisocyanate as a polyisocyanate was added, and the mixture was heated to 60°C while stirring. When the temperature in the reaction container began to drop, the mixture was heated again and stirred at 80°C. The absorption spectrum of the isocyanate group (2280 cm-1) was confirmed by infrared absorption spectrum. -1) disappears, the reaction is terminated, and the solid content concentration is adjusted by adding carbitol acetate to obtain a photosensitive carboxyl-containing polyurethane resin solution. The solid content acid value of the obtained carboxyl-containing polyurethane resin solution (varnish 1) is 50 mgKOH / g, the solid content is 50%, and the weight average molecular weight Mw=17000. In addition, the weight average molecular weight is measured by high-speed liquid chromatography using a pump LC-6AD manufactured by Shimadzu Corporation and three connected chromatographic columns Shodex (registered trademark) KF-804, KF-803, and KF-802 manufactured by Risenoko Co., Ltd.

[0131] [Synthesis Example 2] Preparation of carboxyl-containing resin solution varnish 2

[0132] 377 g of tripropylene glycol monomethyl ether was added to a 2000 ml flask equipped with a stirrer and a cooling tube, and heated to 90°C under a nitrogen stream. A mixture of 104.2 g of styrene, 246.5 g of methacrylic acid, and 20.7 g of dimethyl 2,2'-azobis(2-methylpropionate) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.: V-601) was dissolved and added dropwise to the flask over 4 hours. In this way, a carboxyl-containing resin solution having a skeleton derived from styrene and having no carbamate bonds was obtained. The solid acid value of the obtained carboxyl-containing resin solution (varnish 2) was 120 mgKOH / g, the solid content was 50%, and the weight average molecular weight Mw = 20000. The weight average molecular weight was measured in the same manner as above.

[0133] Preparation of photosensitive resin composition

[0134] The above-mentioned varnish was used as the carboxyl group-containing resin, and the various components shown in Table 1 were mixed in the proportions (parts by mass) described in the table, premixed with a stirrer, and kneaded with a three-roll mill to prepare photosensitive resin compositions 1 to 3. The values ​​in Table 1 are solid content and are parts by mass unless otherwise specified.

[0135]

Table 1

[0136]

[0137]

[0138] In addition, components *1 to *9 in Table 1 are as follows.

[0139] *1: Wetting dispersant (Disperbyk-111, manufactured by BYK)

[0140] *2: Defoaming / leveling agent (BYK-1791, manufactured by BYK)

[0141] *3: Bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad819, manufactured by Agenmon Resins Co., Ltd.)

[0142] *4: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation)

[0143] *5: Antioxidant (IRGANOX 1010, manufactured by BASF Japan Ltd.)

[0144] *6: Thermal curing catalyst (manufactured by Nissan Chemical Co., Ltd.)

[0145] *7: Titanium oxide (TIPAQUE CR-58, average particle size: 0.28 μm, manufactured by Ishihara Sangyo Co., Ltd.)

[0146] *8: Phenol novolac type epoxy resin (diluted diethylene glycol monoethyl ether acetate solution, solid content 75% by mass, manufactured by DIC Corporation)

[0147] *9: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)

[0148] Dispersion stability

[0149] The dispersion stability of the photosensitive resin composition obtained above was evaluated based on JIS K 5600-2-5:1999. Specifically, about 2 g of the photosensitive resin composition was placed on the surface of a grinding tester with a length of 175 mm, a width of 65 mm, a thickness of 19 mm, and a maximum depth of 50 μm, and a scraper with a length of 90 mm, a width of 40 mm, a thickness of 6 mm, and a circular blade with a diameter of 0.25 mm on the long side of the blade tip was used to pull the groove at a uniform speed within 1 to 2 seconds until the depth of the groove was 0. After the end, the groove was observed 3 seconds later to confirm the depth of the groove at the position where the particle size of the particles totaled 5 or more, and the dispersibility was evaluated based on the following evaluation criteria. The results are shown in Table 1.

[0150] Evaluation Benchmarks

[0151] A: Less than 30μm

[0152] B: 30 μm or more and less than 50 μm

[0153] C: 50μm or more

[0154] Preparation of the first membrane

[0155] As the first film, the following films 1 to 8 were prepared. The average transmittance of the prepared films in the wavelength range of 400 nm to 500 nm and the transmittance at 360 nm were measured by the method described later.

[0156] Film 1: A PET film (T-100 manufactured by Toray Industries, Inc.) having a size of 150 mm×150 mm×average thickness of 25 μm was used as Film 1.

[0157] Film 2: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) having a size of 150 mm×150 mm and an average thickness of 25 μm to give an average transmittance of 5%, thereby preparing Film 2.

[0158] Film 3: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm and having an average thickness of 25 μm so as to have an average transmittance of 10%. This film 3 was obtained.

[0159] Film 4: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm and having an average thickness of 25 μm to give an average transmittance of 30%. This film 4 was obtained.

[0160] Film 5: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm and having an average thickness of 25 μm so as to have an average transmittance of 50%. This film 5 was obtained.

[0161] Film 6: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm and having an average thickness of 25 μm so as to have an average transmittance of 70%. This film 6 was obtained.

[0162] Film 7: A carbon black dispersion was applied on one side of a PET film (T-100, manufactured by Toray Industries, Inc.) measuring 150 mm×150 mm and having an average thickness of 25 μm so as to have an average transmittance of 75%. This film was obtained as Film 7.

[0163] Film 8: A carbon black dispersion was mixed with a PET (polyethylene terephthalate) resin and formed into a film of 150 mm×150 mm with a thickness of 25 μm and an average transmittance of 50%. This was used as Film 8 .

[0164] Transmittance of the first film

[0165] The average transmittance of the first film was measured as follows. Films 1 to 8 were cut into 20 mm × 20 mm samples as measurement samples, and the transmittance was measured every 1 nm in the wavelength range of 400 nm to 500 nm using an ultraviolet visible spectrophotometer (manufactured by JASCO Corporation, UV-VIS V570). The average value of the measured transmittance was calculated as the average transmittance. The calculation results are shown in Table 2.

[0166] Similarly, the transmittance was measured at a wavelength of 360 nm, and the transmittance at 360 nm was obtained. The measurement results are shown in Table 2.

[0167] Average thickness of the first film

[0168] The average thickness of the first film is measured as follows. The PET film is cut into 150 mm × 150 mm as a sample for measurement, and the thickness of any 10 locations (parts) is measured using a micrometer (COOLANT PROOF, manufactured by Mitutoyo Co., Ltd.). The arithmetic mean of the measured thicknesses is calculated as the average thickness. The average thickness of the prepared first film is 25 μm.

[0169] Preparation of laminate (dry film)

[0170] Any one of the photosensitive resin compositions 1 to 3 prepared above was applied to the first film shown in Table 2 using a sizing device, and dried at 90° C. for 20 minutes to form a photosensitive resin layer having an average thickness of 45 μm, thereby preparing the laminates (dried films) of Examples 1 to 8 and Comparative Examples 1 to 2. In addition, for the first film coated with the carbon black dispersion, a photosensitive resin layer was formed on the surface coated with the carbon black dispersion.

[0171] The average thickness of the photosensitive resin layer is calculated as the value obtained by subtracting the average thickness of the first film used for each laminate (dry film) from the average thickness of each laminate (dry film). In addition, the average thickness of each laminate (dry film) is measured as follows. Each laminate (dry film) is used as a measurement sample, and a micrometer (COOLANT PROOF manufactured by Mitutoyo Co., Ltd.) is used to measure the thickness of each laminate at any 10 locations (positions). The arithmetic mean of the measured thickness of each laminate is calculated as the average thickness.

[0172] evaluate

[0173] The laminate obtained above was evaluated for average transmittance at 400 nm to 500 nm, reflectivity at 360 nm, sensitivity, and resolution characteristics as follows.

[0174] Average reflectivity

[0175] The photosensitive resin layer of each laminate obtained above is laminated in a manner of contacting a soda-lime glass substrate of 160 mm in length, 110 mm in width and 1.8 mm in thickness. Next, a two-chamber vacuum laminator (manufactured by Nippon Mining Materials Co., Ltd., CVP-300) is used, and the first chamber condition is set to a temperature of 80 ° C, a pressure of 0.4 MPa, and a time of 30 seconds, and the second chamber condition is set to a temperature of 80 ° C, a pressure of 0.78 MPa, and a time of 60 seconds, and the glass substrate and the laminate are laminated, and the first film is peeled off from each laminate to obtain a sample for measuring reflectivity. A colorimeter (manufactured by Konica Minolta Co., Ltd., CM-5) is used for each reflectivity measurement sample, and it is measured with reflected light. The measurement conditions and the measurement method are as follows.

[0176] Measurement conditions

[0177] Software: CM-S100w "SpectraMagic NX"

[0178] Reflexology: SCI

[0179] Measuring diameter: Φ8mm

[0180] The attached zero calibration box CM-A124 was put on to perform zero calibration, and then the built-in white calibration plate was used to perform white calibration. Then, light was incident on each of the laminates obtained above from the photosensitive resin layer side, and the reflectivity in the wavelength range of 400 nm to 500 nm was measured every 1 nm, and the arithmetic mean of the measured values ​​was calculated as the average reflectivity. The results are shown in Table 2.

[0181] Reflectivity at 360nm

[0182] The reflectance of the photosensitive resin layer at 360 nm was measured in the same manner as above.

[0183] Sensitivity

[0184] The photosensitive resin layer of each laminate obtained above was bonded in a manner of contacting with a soda-lime glass substrate of 160 mm in length, 110 mm in width and 1.8 mm in thickness. Next, a two-chamber vacuum laminator (manufactured by Nippon Mining Materials Co., Ltd., CVP-300) was used, with the first chamber conditions set to 80°C, 0.4 MPa, and 30 seconds, and the second chamber conditions set to 80°C, 0.78 MPa, and 60 seconds, to laminate the glass substrate and the laminate, and an exposure device equipped with a high-pressure mercury lamp (short arc lamp) was used to achieve a cumulative exposure of 900 mJ / cm 2In this way, a 41-step step sheet was placed on the first film and exposed from the first film side. Then, the first film of the laminate was peeled off, and after developing with a 1% by mass sodium carbonate aqueous solution at 30°C for 90 seconds, the number of steps of the remaining step sheet was read and evaluated according to the following criteria. The evaluation results are shown in Table 2.

[0185] Evaluation Benchmarks

[0186] A: The number of remaining step pieces is more than 15.

[0187] B: The number of remaining step pieces is 10 or more and 14 or less

[0188] C: The number of remaining step pieces is 5 or more and 9 or less

[0189] D: The number of remaining step pieces is less than 5

[0190] Resolution characteristics

[0191] The photosensitive resin layer of each laminate obtained above was bonded to a soda-lime glass substrate having a length of 160 mm, a width of 110 mm, and a thickness of 1.8 mm. Next, a two-chamber vacuum laminator (manufactured by Nippon Mining Material Co., Ltd., CVP-300) was used, with the first chamber conditions set to 80°C, a pressure of 0.4 MPa, and a time of 30 seconds, and the second chamber conditions set to 80°C, a pressure of 8 kgf / cm 2 , time 60 seconds, the glass substrate and the laminate were laminated, and a 400μm×300μm rectangular pattern was exposed from the first film side using a direct imaging exposure machine (the light source was a high-pressure mercury lamp) to make the cumulative exposure amount 900mJ / cm2. Then, the first film of the laminate was peeled off, and after developing 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 aperture ratio was calculated using the following formula, and the resolution characteristics were evaluated based on the following criteria. The evaluation results are shown in Table 2.

[0192]

Mathematical formula 1

[0193] Opening ratio (%) = calculated opening area (μm 2 ) / 120000(μm 2 )

[0194] Evaluation Benchmarks

[0195] A: The opening rate is above 90%

[0196] B: Opening rate is 80% or more and less than 90%

[0197] C: The opening ratio is more than 70% and less than 80%

[0198] D: Opening ratio greater than 1% and less than 70%

[0199] E: Opening rate less than 1%

[0200]

Table 2

[0201]

[0202] As can be seen from Table 2, when the average reflectivity of the photosensitive resin layer in the wavelength range of not less than 400nm and not more than 500nm is 50% or more, by making the average transmittance of the first film in the wavelength range of not less than 400nm and not more than 500nm be 70% or less, excellent resolution characteristics are exhibited even when exposed through the first film.

[0203] The disclosure of Japanese Patent Application No. 2023-183949 (filing date: October 26, 2023) is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference in the same manner as if each document, patent application, and technical standard were specifically and individually described as being incorporated by reference.

Claims

1. A laminate, wherein: have: a first film having an average transmittance of 70% or less in a wavelength range of 400 nm to 500 nm; and A photosensitive resin layer is disposed on the first film, contains a white pigment, and has an average reflectivity of 50% or more in a wavelength range of 400 nm to 500 nm.

2. The laminate according to claim 1, wherein: The average thickness of the first film is 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. The laminate according to claim 1, wherein: The content of the white pigment in the photosensitive resin layer is 9 mass % or more and 95 mass % or less relative to the total solid content of the photosensitive resin layer.

5. The laminate according to claim 1, wherein: A ratio of an average transmittance of the first film in a wavelength range of 400 nm to 500 nm inclusive to a transmittance at 360 nm is 0.9 to 1.5 inclusive.

6. The laminate according to claim 1, wherein: The ratio of the average reflectivity of the photosensitive resin layer in a wavelength range of 400 nm to 500 nm to the reflectivity at 360 nm is 4.0 or more.

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

8. The laminate according to claim 1, wherein: Also available: A second film is disposed on a surface of the photosensitive resin layer opposite to the first film.

9. A method for forming a pattern, wherein: The following steps are involved: bonding the laminate according to any one of claims 1 to 7 to the substrate in a manner that the photosensitive resin layer faces the substrate; exposing the photosensitive resin layer via the first film of the laminate; The first film is removed to form a pattern on the substrate, wherein the pattern includes a cured product of the photosensitive resin layer.

10. A solidified product, wherein Included in the pattern formed by the pattern forming method according to claim 9.

11. An electronic component, wherein: The method comprises the cured product according to claim 10.

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