Photosensitive resin laminate and method for forming resist pattern

Abstract

A photosensitive resin laminate and a method for forming a resist pattern. The problem is to provide a photosensitive resin laminate excellent in at least one of minimum development time, resolution, amount of side etching (SE), contrast, and bleeding. A photosensitive resin laminate characterized by having a support and a photosensitive resin composition layer formed on the aforementioned support using a photosensitive resin composition containing the following components: (A) an alkali-soluble resin, (B) a photopolymerizable compound having an ethylenic unsaturated bond, (C) a photopolymerization initiator, (D) a compound having increased absorbance in the light wavelength range of 550 to 700 nm, and (E) an organic color developer, the film thickness of the photosensitive resin composition layer being more than 0 and 10 μm or less.

Description

Technical Field

[0001] This invention relates to a method for forming photosensitive resin laminates and resist patterns. Background Technology

[0002] Previously, the manufacturing of printed circuit boards and the precision machining of metals were carried out using photolithography. The photosensitive resin compositions used in photolithography are classified into negative compositions for dissolving and removing unexposed areas and positive compositions for dissolving and removing exposed areas.

[0003] In photolithography, when coating a photosensitive resin composition onto a substrate, any of the following methods can be used:

[0004] (1) A method for coating a photoresist solution onto a substrate and allowing it to dry; and

[0005] (2) A method of laminating a photosensitive resin layer onto a substrate using a photosensitive resin laminate obtained by sequentially laminating a support and a layer containing a photosensitive resin composition (hereinafter also referred to as "photosensitive resin layer") and a protective layer as required.

[0006] The latter method is mostly used in the manufacturing of printed circuit boards.

[0007] The following is a brief description of a method for forming a pattern using the aforementioned photosensitive resin laminate. First, a protective layer is peeled off from the photosensitive resin laminate. Next, using a laminator, the photosensitive resin layer and the support are laminated in the following order on a substrate such as a copper-clad laminate or a copper sputtered film: the substrate, the photosensitive resin layer, and the support. Next, the photosensitive resin layer is exposed through a photomask having the desired wiring pattern. Then, the support is peeled off from the exposed laminate, and non-patterned areas are dissolved or dispersed using a developer, thereby forming a resist pattern on the substrate.

[0008] Furthermore, wiring patterns can also be obtained by subjecting a substrate with resist patterns to etching or plating processes such as copper or tin plating.

[0009] Various photosensitive resin compositions have been studied for forming resist patterns or wiring patterns. For example, Patent Document 1 discloses a photosensitive film having a photosensitive resin layer containing a binder polymer, a photopolymerizable compound, a leuco dye, and a compound that generates acid due to light or heat. This photosensitive film can be sufficiently cured in a desired shape by exposing the photosensitive resin layer before color development, and subsequently, a colored pattern with a desired optical concentration is formed by irradiation with light and / or application of heat.

[0010] Furthermore, Patent Document 2 discloses a photosensitive resin composition using a free radical polymer, which comprises structural units formed of unsaturated double-bonded compounds having bonds capable of decomposition by the action of acid and / or heat of 130°C to 250°C. This photosensitive resin composition enhances its peelability to alkaline peeling solutions by cleaving these bonds with acid and / or heat of 130°C to 250°C before or during peeling after photocuring and development.

[0011] However, in recent years, due to the widespread use of smartphones and other devices, the demand for touch panel displays has been increasing. In the manufacturing of the wiring portion of the sensor in such touch panels, photosensitive resin laminates are mostly used. In the case of touch panel sensors, the wiring manufactured through etching processes generally requires high precision and high density, among other characteristics.

[0012] Existing technical documents

[0013] Patent documents

[0014] Patent Document 1: International Publication No. 2020 / 031379

[0015] Patent Document 2: Japanese Patent Application Publication No. 2009-3000 Summary of the Invention

[0016] The problem the invention aims to solve

[0017] However, sufficient characteristics have not yet been obtained for minimum development time, resolution, lateral etching (SE) amount, contrast, and exudation. Furthermore, there are combinations of these characteristics that are considered difficult to balance; therefore, it is desirable to achieve a balance among various characteristics.

[0018] The present invention is made in view of the existing situation, and the object of the present invention is to provide a method for forming a photosensitive resin laminate and a resist pattern that has excellent minimum development time, resolution, lateral etching (SE) amount, contrast and exudation.

[0019] Solution for solving the problem

[0020] [1] A photosensitive resin laminate, characterized in that it comprises:

[0021] Support body; and

[0022] A photosensitive resin composition layer formed on the aforementioned support using a photosensitive resin composition.

[0023] The photosensitive resin composition comprises the following components:

[0024] (A) Alkali-soluble resins,

[0025] (B) Photopolymerizable compounds with olefinic unsaturated bonds,

[0026] (C) Photopolymerization initiator,

[0027] (D) Compounds with increased absorbance at wavelengths of 550–700 nm, and

[0028] (E) Organic color developer

[0029] The film thickness of the aforementioned photosensitive resin composition layer is greater than 0 and less than 10 μm.

[0030] [2] A photosensitive resin laminate, characterized in that it comprises:

[0031] Support body; and

[0032] A photosensitive resin composition layer formed on the aforementioned support using a photosensitive resin composition.

[0033] The photosensitive resin composition comprises the following components:

[0034] (A) Alkali-soluble resins,

[0035] (B) Photopolymerizable compounds with olefinic unsaturated bonds,

[0036] (C) Photopolymerization initiator,

[0037] (D) Compounds with increased absorbance at wavelengths of 550–700 nm, and

[0038] (E) Organic color developer

[0039] The product of the film thickness (μm) of the aforementioned photosensitive resin composition layer formed on the aforementioned support and the content (mass%) of the aforementioned (E) component relative to the total amount of the aforementioned photosensitive resin composition is greater than 0 and less than 5.0.

[0040] [3] The photosensitive resin laminate according to [1] or [2], wherein the absorbance of the 0.01 mg / ml acetonitrile solution of the aforementioned (E) component is 0.1 or more and less than 1.0 at 330 nm or 405 nm.

[0041] [4] The photosensitive resin laminate according to any one of [1] to [3], wherein, as the aforementioned component (E), it comprises a nonionic organic color developer.

[0042] [5] The photosensitive resin laminate according to any one of [1] to [4], wherein, as the aforementioned component (C), it comprises a roxene dimer.

[0043] [6] The photosensitive resin laminate according to any one of [1] to [5], wherein, as the aforementioned component (D), it comprises a compound having a triarylmethane skeleton.

[0044] [7] The photosensitive resin laminate according to any one of [1] to [6], wherein the weight-average molecular weight of the aforementioned component (A) is 5,000 or more and less than 55,000.

[0045] [8] The photosensitive resin laminate according to any one of [1] to [7], wherein the content of the aforementioned component (A) is 10% to 90% by mass relative to the total amount of the aforementioned photosensitive resin composition.

[0046] [9] The photosensitive resin laminate according to any one of [1] to [8], wherein the content of the aforementioned component (B) is 5% to 70% by mass relative to the total amount of the aforementioned photosensitive resin composition.

[0047]

[10] The photosensitive resin laminate according to any one of [1] to [9], wherein the content of the aforementioned component (C) is 0.01% to 20% by mass relative to the total amount of the aforementioned photosensitive resin composition.

[0048]

[11] The photosensitive resin laminate according to any one of [1] to

[10] , wherein the content of the aforementioned (D) component is 0.001% to 3% by mass relative to the total amount of the aforementioned photosensitive resin composition.

[0049]

[12] The photosensitive resin laminate according to any one of [1] to

[11] , wherein the content of the aforementioned (E) component is more than 0 and less than 3.5% by mass relative to the total amount of the aforementioned photosensitive resin composition.

[0050]

[13] The photosensitive resin laminate according to any one of [1] to

[12] , wherein the content of the aforementioned (E) component is more than 0 and less than 2.5% by mass relative to the total amount of the aforementioned (A) component.

[0051]

[14] The photosensitive resin laminate according to any one of [1] to

[13] , wherein the aforementioned component (A) comprises an aromatic monomer component.

[0052]

[15] The photosensitive resin laminate according to any one of [1] to

[14] , wherein when the color difference of the resist pattern made using the aforementioned photosensitive resin laminate before and after exposure is set as ΔE, and the thickness of the aforementioned photosensitive resin composition layer is set as T [μm], a resist pattern with ΔE / T of 3.5 or more can be formed.

[0053]

[16] The photosensitive resin laminate according to any one of [1] to

[15] , wherein the film thickness of the aforementioned photosensitive resin composition layer is greater than 0 and less than 10 μm.

[0054]

[17] A method for forming a resist pattern, comprising:

[0055] A lamination process in which the photosensitive resin laminate described in any one of [1] to

[16] is laminated onto a substrate;

[0056] An exposure process for exposing the laminated photosensitive resin laminate to light; and

[0057] The developing process involves developing the aforementioned photosensitive resin laminate that has been exposed.

[0058] When the color difference of the resist pattern made using the aforementioned photosensitive resin laminate before and after exposure is set as ΔE, and the thickness of the aforementioned photosensitive resin composition layer is set as T [μm], ΔE / T becomes 3.5 or more.

[0059]

[18] According to the method for forming the resist pattern described in

[17] , the aforementioned exposure process utilizes the following methods: a method of exposure by direct drawing of the pattern without peeling off the support; or an exposure method of projecting the image of the photomask through a lens.

[0060]

[19] According to the resist pattern forming method described in

[17] or

[18] , a light source of 300 to 500 nm is used for exposure in the aforementioned exposure process.

[0061]

[20] The method for forming a resist pattern according to any one of

[17] to

[19] , wherein, after the aforementioned exposure process, the support is peeled off and developed using an inorganic alkaline aqueous solution.

[0062]

[21] The method for forming a resist pattern according to any one of

[17] to

[20] includes: a step of etching a substrate in an area where no pattern is configured after the aforementioned developing step.

[0063] The effects of the invention

[0064] According to the present invention, a method for forming a photosensitive resin laminate and a resist pattern that provides excellent performance in at least one of minimum development time, resolution, lateral etching (SE) amount, contrast, and exudation is available. Detailed Implementation

[0065] The following is a detailed description of this specific embodiment (hereinafter referred to as "Embodiment"). Furthermore, the present invention is not limited to the following Embodiment and can be implemented in various modifications within its scope.

[0066] Furthermore, in this specification, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid, "(meth)acryloyl" refers to acryloyl or methacryloyl, and "(meth)acrylate" refers to acrylate or methacrylate.

[0067] The photosensitive resin laminate of the present invention is characterized in that it has:

[0068] Support body; and

[0069] A photosensitive resin composition layer is formed on a support using a photosensitive resin composition.

[0070] The photosensitive resin composition comprises the following components:

[0071] (A) Alkali-soluble resins,

[0072] (B) Photopolymerizable compounds with olefinic unsaturated bonds,

[0073] (C) Photopolymerization initiator,

[0074] (D) Compounds with increased absorbance at wavelengths of 550–700 nm, and

[0075] (E) Organic color developer

[0076] The film thickness of the photosensitive resin composition layer is greater than 0 and less than 10 μm.

[0077] In the photosensitive resin laminate of the present invention, by including component (D), a photosensitive resin composition with high resolution and excellent distinguishability of the exposed portion can be obtained. By including component (E), a photosensitive resin composition with high sensitivity and excellent distinguishability of the exposed portion can be obtained. Furthermore, by making the film thickness of the photosensitive resin composition layer greater than 0 and less than 10 μm, a photosensitive resin composition with high resolution and excellent peeling properties can be obtained.

[0078] Therefore, the present invention provides a photosensitive resin laminate that excels in at least one of the following: minimum development time, resolution, side etching (SE) amount, contrast, and exudation.

[0079] The following is a detailed explanation of each ingredient.

[0080] <(A) Alkali-soluble resin>

[0081] (A) The alkali-soluble resin is a polymer that is soluble in alkaline solutions. Furthermore, (A) the alkali-soluble resin preferably has carboxyl groups, more preferably has an acid equivalent of 100 to 600, and even more preferably is a copolymer containing carboxyl-containing monomers as copolymerizing components. Furthermore, (A) the alkali-soluble resin can be thermoplastic.

[0082] (A) The acid value (mgKOH / g) of the alkali-soluble resin is preferably greater than 0, and from the viewpoints of the developability of the photosensitive resin layer, the resolution and adhesion of the resist pattern, and further from the viewpoints of the developability and peelability of the photosensitive resin layer, it is preferably 200 or less.

[0083] Furthermore, (A) the acid value (acid equivalent) of the alkali-soluble resin is more preferably greater than 0 and less than 78.0, and even more preferably greater than 0 and less than 76.0.

[0084] The acid value in the aforementioned range is equivalent to the so-called "low acid value" compared to the prior art. In one embodiment of the present invention, the "thinning of the photosensitive resin layer" and the "low acid value" are achieved, given the recent demand for thin-film photosensitive resin layers.

[0085] Previously, increasing the hydrophobicity of the photoresist was known as a method to achieve high resolution (low SE). However, increasing the hydrophobicity of the photoresist reduces its solubility in the developer, thus tending to increase the development time. Furthermore, reducing the molecular weight of the resin to shorten the development time can sometimes also easily reduce Cu defects (film strength).

[0086] (A) The glass transition temperature (Tg) of alkali-soluble resins is obtained by the following mathematical formula (I). total Preferably, the temperature is below 100℃.

[0087] [Mathematical Expression 1]

[0088]

[0089] In the formula, W i The mass of each comonomer that constitutes the alkali-soluble resin.

[0090] Tg i The glass transition temperature is the temperature at which the comonomers constituting the alkali-soluble resin are homopolymers.

[0091] W total This refers to the total mass of the alkali-soluble resin, and

[0092] n represents the number of types of comonomers that constitute the alkali-soluble resin.

[0093] When a mixture of various polymers is used as an alkali-soluble resin (A), the glass transition temperature is a value determined as the average value of all polymers.

[0094] Calculate the glass transition temperature Tg iWhen, as the glass transition temperature of the homopolymer formed from the corresponding comonomer that forms the alkali-soluble resin, the value is shown in "Polymer handbook, Third edition, John Wiley & Sons, 1989, p. 209, Chapter VI, Glass transition temperatures of polymers", edited by Brandrup, J. Immergut, EH.

[0095] Tg of representative comonomers i The following are examples (all are reference values).

[0096] Methacrylic acid: Tg = 501K

[0097] Benzyl methacrylate: Tg = 327K

[0098] Methyl methacrylate: Tg = 378K

[0099] Styrene: Tg = 373K

[0100] 2-Ethylhexyl acrylate: Tg = 223K

[0101] Cyclohexyl methacrylate: Tg = 365K

[0102] Butyl acrylate: Tg = 219K

[0103] As shown above, the glass transition temperature (Tg) total Alkali-soluble resins, preferably copolymers of acid monomers and other monomers.

[0104] Regarding the glass transition temperature (Tg) of the alkali-soluble resin (A) obtained through the above mathematical formula (I), total The lower limit of the glass transition temperature (Tg) is not specifically defined. total The temperature can be above 10℃, above 30℃, above 50℃, or above 70℃.

[0105] The weight-average molecular weight (Mw) of the alkali-soluble resin (A) is preferably 5,000 or more and less than 55,000. From the viewpoint of uniformly maintaining the thickness of the photosensitive resin laminate such as the dry film resist layer and obtaining resistance to developer, the weight-average molecular weight of the alkali-soluble resin (A) is preferably 5,000 or more. On the other hand, from the viewpoint of maintaining the developability of the photosensitive resin laminate such as the dry film resist layer, it is preferably less than 55,000. Furthermore, the weight-average molecular weight (Mw) of the alkali-soluble resin (A) is more preferably 10,000 to 50,000, and even more preferably 23,000 to 50,000. Moreover, the ratio of the above-mentioned Mw to the number-average molecular weight (Mn) of the alkali-soluble resin (A), i.e., the dispersion (Mw / Mn) of the alkali-soluble resin (A), is preferably 1.0 to 6.0.

[0106] (A) The alkali-soluble resin is preferably obtained by polymerizing at least one of the first monomers described later. (A) The alkali-soluble resin preferably contains an aromatic monomer component included in the second monomer described later. Furthermore, (A) The alkali-soluble resin is more preferably obtained by copolymerizing at least one of the first monomers with at least one of the second monomers described later.

[0107] The first monomer is a monomer containing a carboxyl group in its molecule. Examples of first monomers include (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, β-carboxyethyl (meth)acrylic acid, and maleic acid half ester. Among these, (meth)acrylic acid is particularly preferred.

[0108] Examples of second monomers include unsaturated aromatic compounds (sometimes referred to as "aromatic monomers"), alkyl (meth)acrylates, aralkyl (meth)acrylates, conjugated dienes, polar monomers, and crosslinking monomers. Among these, unsaturated aromatic compounds are preferred from the viewpoint of improving the resolution of the resist pattern. When using a second monomer containing an unsaturated aromatic compound, the proportion of the unsaturated aromatic compound relative to the total amount of (A) alkali-soluble resin is preferably 5% by mass or more, and more preferably 10% by mass or more.

[0109] Examples of unsaturated aromatic compounds include benzyl (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, styrene, cinnamic acid, and polymerizable styrene derivatives (e.g., methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, 4-vinylbenzoic acid, styrene dimers, styrene trimers, etc.). Among these, benzyl (meth)acrylate and styrene are preferred, and benzyl (meth)acrylate is more preferred.

[0110] Alkyl methacrylates are a concept that includes both chain alkyl esters and cyclic alkyl esters. Specifically, examples include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, stearyl methacrylate, and cyclohexyl methacrylate.

[0111] Examples of aralkyl (meth)acrylates include benzyl (meth)acrylate, and examples of conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. Examples of polar monomers include hydroxyl-containing monomers such as hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, and pentenol; amino-containing monomers such as 2-aminoethyl methacrylate; amide-containing monomers such as (meth)acrylamide and N-hydroxymethyl(meth)acrylamide; cyano-containing monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and α-cyanoethyl acrylate; and epoxy-containing monomers such as glycidyl methacrylate and 3,4-epoxycyclohexyl methacrylate.

[0112] Examples of cross-linking monomers include trimethylolpropane triacrylate and divinylbenzene.

[0113] (A) The alkali-soluble resin can be prepared by means of the first monomer and / or the second monomer described above by known polymerization methods, preferably by addition polymerization, and more preferably by free radical polymerization.

[0114] The content of alkali-soluble resin (A) in the photosensitive resin composition (based on the total solid content of the photosensitive resin composition; unless otherwise specified, this applies to each component) is preferably in the range of 10% to 90% by mass, more preferably in the range of 20% to 80% by mass, and even more preferably in the range of 30% to 60% by mass. From the viewpoint of maintaining the alkali developability of the photosensitive resin layer, the content of alkali-soluble resin (A) is preferably 10% by mass or more; on the other hand, from the viewpoint of fully utilizing the performance of the resist pattern formed by exposure as a resist material, it is preferably 90% by mass or less.

[0115] <(B) Photopolymerizable compounds with olefinic unsaturated bonds>

[0116] (B) Photopolymerizable compounds with olefinic unsaturated bonds are compounds that possess polymerizability by having olefinic unsaturated bonds, specifically olefinic unsaturated groups, in their structure.

[0117] In the photosensitive resin composition, component (B) only needs to have one or more olefinic double bonds. It is preferable to use a compound having two or more olefinic double bonds.

[0118] Specifically, as component (B), examples include, for instance, di(meth)acrylate of polyalkylene glycols obtained by adding an average of 2 to 15 moles of epoxy alkane to both ends of bisphenol A; tri(meth)acrylate of polyalkylene triols obtained by adding an average of 3 to 25 moles of epoxy alkane to trimethylolpropane; compounds obtained by converting alcohols obtained by adding polyalkylene oxide groups such as glycerol, trimethylolpropane, pentaerythritol, diglycerol, bis(trimethylolpropane), and isocyanurate rings to (meth)acrylate or by modifying them with ε-caprolactone; or compounds obtained by reacting them directly with (meth)acrylic acid without modifying them with epoxy alkane groups or ε-caprolactone; tetra(meth)acrylate of polyols obtained by adding an average of 4 to 35 moles of epoxy alkane to pentaerythritol; and hexa(meth)acrylate of polyols obtained by adding an average of 4 to 30 moles of epoxy alkane to dipentaerythritol. They can be used individually or in combination of two or more.

[0119] The content of the photopolymerizable compound (B) having an olefinic unsaturated group in the photosensitive resin composition is preferably 5% to 70% by mass, more preferably 20% to 60% by mass, and even more preferably 30% to 50% by mass. Regarding the content of the compound (B) having an olefinic unsaturated group, from the viewpoint of suppressing poor curing of the photosensitive resin layer and delay in development time, it is preferably 5% by mass or more; on the other hand, from the viewpoint of suppressing delay in peeling of the cured resist layer, it is preferably 70% by mass or less.

[0120] <(C) Photopolymerization initiator>

[0121] (C) The photopolymerization initiator is a compound that can generate free radicals through active light and polymerize (B) a photopolymerizable compound having an olefinic unsaturated group. The photosensitive resin composition may contain substances generally known in the art as the (C) photopolymerization initiator.

[0122] Examples of photopolymerization initiators (C) include hexaaryl biimidazole compounds, N-aryl-α-amino acid compounds, quinone compounds, aromatic ketone compounds, acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, benzoin ether compounds, dialkyl ketal compounds, thioxanone compounds, dialkylaminobenzoate compounds, oxime ester compounds, acridine compounds, pyrazoline derivatives, ester compounds of N-aryl amino acids, and halogen compounds.

[0123] Examples of hexaaryl biimidazole compounds include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole (also known as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), 2,2',5-tris(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, 2,4-bis(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)diphenylbiimidazole, 2,4,5-tris(o-chlorophenyl)diphenylbiimidazole, and 2-(o-chlorophenyl)-bis-4,5-(3,4- 2,2'-bis(2-fluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3-difluoromethylphenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,4-difluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,5-difluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,6-difluorophenyl)-4,4', 5,5'-Tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3,4-trifluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3,5-trifluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3,6-trifluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,4,5-trifluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'- Bis(2,4,6-trifluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, 2,2'-bis(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole and 2,2'-bis(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetra(3-methoxyphenyl)biimidazole, lofenidine (2,4,5-triarylimidazole) dimer, etc.

[0124] Lofenol dimers include, for example, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-bis(m-methoxyphenyl)imidazolium dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazolium dimer. In particular, from the viewpoint of high sensitivity, resolution and tightness, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer is preferred.

[0125] Examples of N-aryl-α-amino acid compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. N-phenylglycine, in particular, exhibits high sensitization efficacy and is therefore preferred.

[0126] Examples of quinone compounds include 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthroquinone, 2-methyl-1,4-naphthoquinone, 9,10-phenanthroquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone.

[0127] Examples of aromatic ketone compounds include benzophenone, michidone [4,4'-bis(dimethylamino)benzophenone], 4,4'-bis(diethylamino)benzophenone, and 4-methoxy-4'-dimethylaminobenzophenone.

[0128] Examples of acetophenone compounds include 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)one, 1-hydroxycyclohexylphenylone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoacetone-1. Commercially available acetophenone compounds include, for example, Irgacure-907, Irgacure-369, and Irgacure-379 manufactured by Ciba Specialty Chemicals. From the viewpoint of its use as a sensitizer and its adhesion, 4,4'-bis(diethylamino)benzophenone is preferred.

[0129] Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Commercially available examples of acylphosphine oxide compounds include Lucirin TPO manufactured by BASF and Irgacure-819 manufactured by Ciba Specialty Chemicals.

[0130] Examples of benzoin compounds and benzoin ether compounds include, for example, benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, ethyl benzoin, etc.

[0131] Examples of dialkyl ketals include benzoyl dimethyl ketal and benzoyl diethyl ketal.

[0132] Examples of thioxanthone compounds include 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone.

[0133] Examples of dialkylaminobenzoate compounds include ethyl dimethylaminobenzoate, ethyl diethylaminobenzoate, ethyl p-dimethylaminobenzoate, and 2-ethylhexyl 4-(dimethylamino)benzoate.

[0134] Examples of oxime ester compounds include 1-phenyl-1,2-propanedione-2-O-benzoyl oxime and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Commercially available oxime ester compounds include, for example, CGI-325, Irgacure-OXE01, and Irgacure-OXE02 manufactured by Ciba Specialty Chemicals.

[0135] From the viewpoints of sensitivity, resolution, and availability, 1,7-bis(9,9'-acridyl)heptane or 9-phenylacridinium is preferred as an acridine compound.

[0136] From the viewpoint of tightness and the rectangularity of the anti-corrosion pattern, 1-phenyl-3-(4-tert-butylstyryl)-5-(4-tert-butylphenyl)pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)pyrazoline and 1-phenyl-3-(4-biphenyl)-5-(4-tert-octylphenyl)pyrazoline are preferred as pyrazoline derivatives.

[0137] Examples of ester compounds of N-aryl amino acids include methyl ester of N-phenylglycine, ethyl ester of N-phenylglycine, n-propyl ester of N-phenylglycine, isopropyl ester of N-phenylglycine, 1-butyl ester of N-phenylglycine, 2-butyl ester of N-phenylglycine, tert-butyl ester of N-phenylglycine, pentyl ester of N-phenylglycine, hexyl ester of N-phenylglycine, pentyl ester of N-phenylglycine, and octyl ester of N-phenylglycine.

[0138] Examples of halogen compounds include pentyl bromide, isopentyl bromide, isobutylene bromide, ethylene bromide, diphenyl bromide methane, benzyl bromide, dibromomethane, tribromomethylphenyl sulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, pentyl iodine, isobutyl iodine, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, triazine chloride compounds, diallyl iodonium compounds, etc., with tribromomethylphenyl sulfone being particularly preferred.

[0139] The content of (C) photopolymerization initiator in the photosensitive resin composition is preferably 0.01% to 20% by mass, more preferably 0.5% to 10% by mass. By adjusting the content of (C) photopolymerization initiator to the above range, a photosensitive resin composition that can obtain sufficient sensitivity, can fully transmit light to the bottom of the resist layer, can obtain high resolution, and has an excellent balance with the amount of lateral etching of the conductor pattern can be obtained.

[0140] From the viewpoints of high sensitivity, resolution, and adhesion, a levofloxacin dimer is preferably included as the (C) photopolymerization initiator. In this case, the content of the levofloxacin dimer in the photosensitive resin composition is preferably 0.1% to 10% by mass, more preferably 0.5% to 5% by mass.

[0141] <(D) Compounds with increased absorbance in the wavelength range of 550–700 nm>

[0142] (D) is a compound whose structure changes when exposed to light with a wavelength of 300 to 500 nm, thereby increasing the absorbance at a wavelength of 550 to 700 nm. By including this (D) component, the photosensitive resin composition can obtain a photosensitive resin composition with high resolution and excellent recognition of the exposed area.

[0143] Examples of such (D) components include, for example, triarylmethane compounds, spiropyran compounds, fluorane compounds, diarylmethane compounds, rhodamine lactam compounds, indolylphthalide compounds, leucoauramine compounds, phenothiazine compounds, xanthine compounds, and oxazine compounds.

[0144] From the viewpoint of the identifiability of the exposed section, as component (D), it is preferable to include a compound having a triarylmethane skeleton.

[0145] Examples of compounds with a triarylmethane skeleton include tris(4-dimethylaminophenyl)methane [leuco crystal violet], green DCF, methylene blue, thymol blue, bromothymol blue, bromophenol blue, aqua blue, solvent blue 5, basic blue 7, xylene blue, Coomassie Brilliant Blue G250, Coomassie Brilliant Blue R250, brilliant blue FCF, green S, malachite green, fast green FCF, basic violet 3, basic violet 4, methyl violet 2B, methyl violet 6B, methyl violet 10B, crystal violet lactone, phenolphthalein, phenol red, cresol red, fuchsin O, and flame red dyes. Among these, malachite green or basic violet 3 is preferred.

[0146] The content of component (D) in the photosensitive resin composition is preferably 0.001% to 3% by mass, more preferably 0.002% to 2% by mass. By adjusting the content of component (D) to the above range, a photosensitive resin composition that can obtain sufficient sensitivity, can fully transmit light to the bottom of the resist layer, can obtain high resolution, and has an excellent balance with the amount of lateral etching in the conductor pattern can be obtained.

[0147] <(E) Organic color developer>

[0148] (E) Organic color developers are compounds that produce acids when exposed to radiation such as ultraviolet light, far ultraviolet light, X-rays, and charged particle beams. By including such (E) organic color developers, photosensitive resin compositions can be obtained that offer high resolution, high sensitivity, and excellent recognition of the exposed portion.

[0149] Examples of organic colorimetric agents (E) include trichloromethyl-s-triazine compounds, diazomethane compounds, imide sulfonate compounds and oxime sulfonate compounds, diaryliodonium salts, triarylsulfonium salts, and other onium salts that decompose and produce acid upon light irradiation; quaternary ammonium salts, etc. Among these, oxime sulfonate compounds and imide sulfonate compounds are preferred from the viewpoint of absorption wavelength and the strength of the generated acid.

[0150] As (E) organic color developers, examples include (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, naphthalenedicarboximide trifluoromethylsulfonate, naphthalenedicarboximide methanesulfonate, and naphthalenedicarboximide camphor sulfonate.

[0151] (E) The absorbance of a 0.01 mg / ml acetonitrile solution of the organic color developer at 330 nm or 405 nm is preferably 0.1 or more. Furthermore, this absorbance is preferably less than 1.0, more preferably 0.15 or more and less than 0.9. This allows for the production of a photosensitive resin composition with high sensitivity and excellent discernibility of the exposed portion.

[0152] From the viewpoint of the storage stability and color development stability of photosensitive resin laminates, it is preferable to use an organic color developer containing nonionic components as the (E) organic color developer. This allows for the formation of photosensitive resin laminates that can stably maintain resolution and the distinguishability of exposed areas even during long-term storage.

[0153] Examples of nonionic organic colorimetric agents include trichloromethyl-S-triazine compounds, diazomethane compounds, imide sulfonate compounds, and oxime sulfonate compounds. Among these, oxime sulfonate compounds and imide sulfonate compounds are preferred from the viewpoint of absorption wavelength and the strength of the acid produced.

[0154] The content of the (E) organic color developer in the photosensitive resin composition is more than 0 and less than 3.5% by mass, preferably 0.0005% to 3% by mass, more preferably 0.001% to 2% by mass, and even more preferably 0.5% to 0.9% by mass. By adjusting the content of the (E) organic color developer to the above range, a photosensitive resin composition with excellent compatibility with the composition, sufficient sensitivity, sufficient light transmission to the bottom of the resist layer, high resolution, and excellent balance between the amount of lateral etching and the conductor pattern can be obtained.

[0155] In particular, for the same reasons as above, the content of (E) organic color developer relative to the total amount of (A) alkali-soluble resin is preferably more than 0 and less than 2.5% by mass.

[0156] <Other Ingredients>

[0157] The photosensitive resin composition preferably includes additives such as basic dyes, antioxidants, stabilizers, sensitizers, and plasticizers, as desired. It should be noted that the other components are those not included in (A) to (E) above.

[0158] To impart color development and excellent peeling properties to the unexposed portion, a basic dye can be mixed into the photosensitive resin composition of this embodiment. Examples include Basic Green 1 [CAS No. (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Magenta [632-99-5], Methyl Violet [603-47-4], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], etc. Among these, Basic Green 1 is preferred from the viewpoint of improving colorfastness, hue stability, and exposure contrast. They can be used individually or in combination of two or more.

[0159] The content of the basic dye in the photosensitive resin composition is preferably in the range of 0.001% to 3% by mass, more preferably in the range of 0.01% to 2% by mass, and even more preferably in the range of 0.04% to 1% by mass. From the viewpoint of obtaining good colorability, the dye content is preferably 0.001% by mass or more; on the other hand, from the viewpoint of maintaining the sensitivity of the photosensitive resin layer, the dye content is preferably 3% by mass or less.

[0160] Examples of antioxidants include triphenyl phosphite (e.g., manufactured by Asahi Denka Kogyo Co., Ltd., trade name: TPP), tris(2,4-di-tert-butylphenyl) phosphite (e.g., manufactured by Asahi Denka Kogyo Co., Ltd., trade name: 2112), tris(mononophenyl) phosphite (e.g., manufactured by Asahi Denka Kogyo Co., Ltd., trade name: 1178), and bis(mononophenyl)dionophenyl phosphite (e.g., manufactured by Asahi Denka Kogyo Co., Ltd., trade name: 329K). They can be used alone or in combination of two or more.

[0161] The antioxidant content in the photosensitive resin composition is preferably in the range of 0.01% to 0.8% by mass, more preferably in the range of 0.01% to 0.3% by mass. Regarding the antioxidant content, from the viewpoint of exhibiting good hue stability of the resist pattern and improving the sensitivity of the photosensitive resin layer, it is preferably 0.01% by mass or more; on the other hand, from the viewpoint of both suppressing the color development of the resist pattern and exhibiting good hue stability and improving adhesion, it is preferably 0.8% by mass or less.

[0162] From the viewpoint of improving the thermal stability and / or storage stability of the photosensitive resin composition, a stabilizer is preferred. Examples of stabilizers include at least one compound selected from the group consisting of free radical polymerization inhibitors and epoxy alkane compounds having glycidyl groups. They can be used alone or in combination of two or more.

[0163] Examples of free radical polymerization inhibitors include p-methoxyphenol, hydroquinone, biphenyl pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], aluminum salts of nitrosophenylhydroxylamine (e.g., aluminum salts with 3 moles of nitrosophenylhydroxylamine added), and diphenylnitrosamine. Among these, triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] or aluminum salts with 3 moles of nitrosophenylhydroxylamine added are preferred. Furthermore, one of these can be used alone, or two or more can be used in combination.

[0164] Examples of epoxide alkane compounds containing a glycidyl group include neopentyl glycol diglycidyl ether (e.g., EPOLIGHT 1500NP manufactured by Kyoeisha Chemical Co., Ltd.), nonaethylene glycol diglycidyl ether (e.g., EPOLIGHT 400E manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2-molar adduct diglycidyl ether (e.g., EPOLIGHT 3002 manufactured by Kyoeisha Chemical Co., Ltd.), and 1,6-hexanediol diglycidyl ether (e.g., EPOLIGHT 1600 manufactured by Kyoeisha Chemical Co., Ltd.). They can be used alone or in combination of two or more.

[0165] The total content of the free radical polymerization inhibitor and the glycidyl group-containing epoxy alkane compound in the photosensitive resin composition is preferably in the range of 0.001% to 3% by mass, more preferably in the range of 0.05% to 1% by mass. From the viewpoint of imparting good storage stability to the photosensitive resin composition, this total content is preferably 0.001% by mass or more; on the other hand, from the viewpoint of maintaining the sensitivity of the photosensitive resin layer, this total content is preferably 3% by mass or less.

[0166] <Photosensitive Resin Composition Mixture>

[0167] In one embodiment, a photosensitive resin composition blend can be formed by adding a solvent to the photosensitive resin composition. Suitable solvents include ketones such as acetone and methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropanol. Preferably, the solvent is added to the photosensitive resin composition such that the viscosity of the photosensitive resin composition blend is 500 mPa·sec to 4000 mPa·sec at 25°C.

[0168] <Photosensitive resin laminate, dry film resist layer and transfer film>

[0169] Using the photosensitive resin composition or photosensitive resin composition blending solution of this application, a photosensitive resin laminate can be provided. The photosensitive resin laminate has a support film (support body) and a layer formed on the support film containing the aforementioned photosensitive resin composition. The photosensitive resin laminate may, as needed, have a protective layer on the surface opposite to the support film side. From the viewpoint of significantly maximizing the effects of the present invention, the photosensitive resin laminate is preferably a dry film resist or a transfer film, more preferably a dry film resist.

[0170] As a support film, it is desirable to have a transparent film that allows light emitted from the exposure light source to pass through. Examples of such support films include polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. Stretched films may also be used as needed.

[0171] The haze of the support film is preferably 5 or less. A thin support film is advantageous from the perspectives of image formation and economy; if the function of maintaining strength is also taken into consideration, a thickness of 10 μm to 30 μm is preferred.

[0172] The layer of the photosensitive resin composition described above (hereinafter also referred to as the "photosensitive resin layer") may comprise or be formed from the photosensitive resin composition. From the viewpoint of the resolution of the resist pattern, the amount of lateral etching, the puncture strength, or the peel strength, the film thickness of the layer of the photosensitive resin composition in the photosensitive resin laminate is preferably 0.5 μm to 25 μm, more preferably 1 μm to 20 μm. From the same viewpoint, the upper limit of this film thickness is further preferably 16 μm or less, particularly preferably 10 μm or less, and most preferably less than 10 μm.

[0173] An important characteristic of the protective layer used in photosensitive resin laminates is that it has appropriate adhesion. In other words, preferably, the adhesion force of the protective layer to the photosensitive resin layer is sufficiently less than the adhesion force of the supporting film to the photosensitive resin layer, allowing the protective layer to be easily peeled off from the photosensitive resin laminate. Examples of protective layers that can be used include polyethylene film, polypropylene film, polyethylene terephthalate film, and polyester film. Furthermore, a release layer suitable for peeling off the protective film from the photoresist layer can be applied to one side of the aforementioned protective layer film. Release layers are generally classified as silicone compounds and non-silicone compounds. Organosilicon compounds refer to: condensation-reaction type organosilicon resins obtained by reacting end-terminated silanol polydimethylsiloxane with polymethylhydrosiloxane or polymethylmethoxysiloxane; addition-reaction type organosilicon resins obtained by reacting dimethylsiloxane-methylvinylsiloxane copolymer or dimethylsiloxane-methylhexenylsiloxane copolymer with polymethylhydrosiloxane; UV-curable or electron-ray-curable organosilicon resins obtained by curing acrylic organosilicon, epoxy-containing organosilicon, etc., using ultraviolet light or electron beams; modified organosilicon resins, such as epoxy-modified organosilicon resins (organosilicon epoxy), polyester-modified organosilicon resins (organosilicon polyester), acrylic-modified organosilicon resins (organosilicon acrylic), phenol-modified organosilicon resins (organosilicon phenol), alkyd-modified organosilicon resins (organosilicon alkyd), melamine-modified organosilicon resins (organosilicon melamine), etc. Non-organosilicon compounds refer to alkyd resins, long-chain alkyl resins, acrylic resins, and polyolefin resins, etc. The thickness of the release layer is preferably 0.001–2 μm, more preferably 0.005–1 μm, and even more preferably 0.01–0.5 μm. When the film thickness exceeds 2 μm, the coating appearance may deteriorate, and the coating may not cure sufficiently; when the film thickness is less than 0.001 μm, sufficient release properties may not be achieved. The thickness of the protective layer is preferably 10 μm–100 μm, more preferably 10 μm–50 μm.

[0174] <Preparation Method of Photosensitive Resin Laminates>

[0175] Photosensitive resin laminates can be manufactured by sequentially laminating photosensitive resin layers and, if necessary, protective layers onto a support film (support). Known methods can be employed as a method. For example, the photosensitive resin composition used in the photosensitive resin layers is mixed with a solvent in which they are dissolved to form a homogeneous solution of the photosensitive resin composition (coating solution). The coating solution is then applied to the support film using a bar coater or roller coater, followed by drying, thereby enabling the photosensitive resin layers to be laminated onto the support film. If necessary, a photosensitive resin laminate can be manufactured by laminating a protective layer onto the photosensitive resin layers.

[0176] In the photosensitive resin laminate of this embodiment, the product of the film thickness (μm) of the photosensitive resin layer formed on the support film (support) and the content (mass%) of the organic color developer (E) relative to the total amount of the photosensitive resin composition is greater than 0 and less than 5.0.

[0177] In this embodiment, the focus is on forming the photosensitive resin layer into a thin film and adjusting the content of the (E) organic color developer to a specific small range. By limiting the product of the film thickness (μm) of the photosensitive resin layer and the content of the (E) organic color developer to a specific range, a photosensitive resin laminate with sufficient sensitivity, sufficient light transmission to the bottom of the resist layer, higher resolution, and a particularly excellent balance with the amount of lateral etching of the conductor pattern can be obtained.

[0178] Furthermore, in the photosensitive resin laminate of this embodiment, when the color difference of the resist pattern made using the photosensitive resin laminate before and after exposure is set as ΔE, and the thickness of the aforementioned photosensitive resin composition layer is set as T [μm], a resist pattern with ΔE / T of 3.5 or more can be formed.

[0179] <Method for Forming Anti-corrosion Patterns>

[0180] Another aspect of the present invention provides a method for forming a resist pattern, which includes the following steps:

[0181] The process of laminating the photosensitive resin laminate of this application onto a substrate (lamination process);

[0182] The process of exposing a laminated photosensitive resin laminate (exposure process); and the process of developing the exposed photosensitive resin laminate (development process).

[0183] In particular, in this embodiment, when the color difference of the resist pattern made using the photosensitive resin laminate before and after exposure is set as ΔE, and the thickness of the photosensitive resin composition layer is set as T [μm], from the viewpoint of improving the distinguishability of the exposed and unexposed parts, ΔE / T is 3.5 or more, preferably 4.0 or more.

[0184] In the resist pattern forming method of this embodiment, the color difference ΔE of the resist pattern formed using a photosensitive resin laminate before and after exposure can be 8.0 or more. From the viewpoint of improving contrast, this color difference ΔE is preferably 10 or more, and more preferably 11 or more.

[0185] It should be noted that, in this specification, the color difference ΔE of the resist pattern before and after exposure is measured using the method described in the embodiments described later.

[0186] <Methods for forming wiring patterns>

[0187] Another aspect of this application provides a wiring pattern forming method, which includes the following steps:

[0188] The process of etching or plating a substrate on which a resist pattern has been formed using the aforementioned resist pattern forming method (etching or plating process).

[0189] The following describes an example of a method for forming a resist layer and wiring patterns using a photosensitive resin laminate and a substrate.

[0190] (Lamination process)

[0191] When the photosensitive resin laminate has a protective layer, the lamination process can be performed as follows: after peeling the protective layer from the laminate, for example, the photosensitive resin layer is heated and pressed onto the surface of the substrate using a laminator, and lamination is performed.

[0192] Examples of materials used as substrates include copper (Cu), stainless steel (SUS), glass, indium tin oxide (ITO), and flexible substrates with laminated conductive films. Examples of conductive films include ITO, copper, copper-nickel alloys, and silver. Examples of materials constituting flexible substrates include polyethylene terephthalate (PET).

[0193] The substrate used can be in the form of copper wiring formed on a copper-clad laminate, a substrate made of glass only, or a transparent resin substrate with transparent electrodes (e.g., ITO, Ag nanowire substrates, etc.) or metal electrodes (e.g., Cu, Al, Ag, Ni, Mo, and alloys of at least two of them) formed on it. Furthermore, the substrate can have through-holes for use with the multilayer substrate.

[0194] From the viewpoint of maximizing the effects of the present invention, the substrate used is preferably a copper-clad laminate substrate, and more preferably a copper-clad laminate substrate having a copper foil with a thickness of 35 μm, a thickness of 1.6 mm, and a through hole with a diameter of 6 mm.

[0195] The photosensitive resin layer can be laminated onto only one side of the substrate surface, or it can be laminated onto both sides of the substrate as needed. The heating temperature during lamination is preferably 40°C to 160°C, more preferably 80°C to 120°C. Performing two or more heat-pressing processes can also improve the adhesion of the resulting resist pattern to the substrate. When performing two or more pressing processes, a two-stage laminator equipped with two continuous rollers can be used, or the laminate of the substrate and the photosensitive resin layer can be repeatedly pressed through the rollers.

[0196] (Exposure process)

[0197] In the exposure process, an exposure machine is used to expose the photosensitive resin layer. From the viewpoint of mask contamination and dimensional stability, the following methods are preferred for this exposure: a method of exposure by direct drawing of a pattern without peeling off the support, or an exposure method of projecting the image of the photomask through a lens.

[0198] By performing this patterned exposure, a resist film (resist pattern) with the desired pattern can be obtained after the development process described later. The patterned exposure can be based on either exposure through a light mask or maskless exposure.

[0199] When exposure is performed through a photomask, the exposure amount is determined by the illuminance of the light source and the exposure time. The exposure amount can be measured using a photometer. In maskless exposure, no photomask is used; exposure is performed on the substrate using a direct drawing device. As the light source, semiconductor lasers with wavelengths of 300–500 nm, ultra-high pressure mercury lamps, etc., can be used. In maskless exposure, the pattern drawing is computer-controlled, and the exposure amount can be determined by the illuminance of the exposure light source and the moving speed of the substrate.

[0200] From the perspective of improving the resolution of the resist pattern, reducing the amount of lateral etching, or increasing the yield of the resist layer or wiring pattern, it is preferable to expose through a photomask.

[0201] (Developing process)

[0202] In the developing process, a developing solution is used to remove the non-patterned areas of the photosensitive resin layer. In the developing process, the support is peeled off, and a developing solution formed from an inorganic alkaline aqueous solution is used. When a negative photosensitive resin composition is used, the unexposed areas are removed by dissolving to obtain a resist pattern. When a positive photosensitive resin composition is used, the exposed areas are removed by dissolving to obtain a resist pattern.

[0203] As the alkaline aqueous solution, inorganic alkaline aqueous solutions such as Na₂CO₃ and K₂CO₃ are preferred. The alkaline aqueous solution is selected according to the characteristics of the photosensitive resin composition layer, and a Na₂CO₃ aqueous solution with a concentration of 0.2% to 2% by mass is preferred. Surfactants, defoamers, and small amounts of organic solvents for promoting development can be mixed into the alkaline aqueous solution. The temperature of the developing solution in the developing process is preferably maintained at a constant temperature within the range of 18°C ​​to 40°C.

[0204] Ideally, a heating process can be performed after the developing process to heat the resulting resist pattern at 100°C to 300°C. By implementing this heating process, the chemical resistance and resolution of the resist pattern can sometimes be improved. Heating can be performed using an appropriate heating furnace, such as one employing hot air, infrared radiation, or far-infrared radiation.

[0205] (Etching or plating process)

[0206] After forming a resist pattern using the above-described resist pattern forming method, wiring patterns can be formed on the substrate by etching or plating the substrate in areas where the resist pattern is not configured. From the viewpoint of significantly maximizing the effects of the present invention, it is preferable to perform at least an etching step.

[0207] The etching process can be performed using known etching methods, such as etching the substrate surface not covered by the resist pattern by blowing etching solution over the resist pattern. Examples of etching methods include acid etching and alkaline etching, performed using a method suitable for the photosensitive resin laminate used. The etching solution can be, for example, an aqueous solution of hydrochloric acid, an aqueous solution of ferric chloride, or a mixture thereof. Furthermore, the etching solution can be sprayed.

[0208] The plating process can be carried out according to known plating methods, by metal plating (e.g., using copper sulfate plating solution) or tin plating on the surface of the substrate exposed by development.

[0209] After the etching and / or plating processes, the photosensitive resin laminate can be treated with an aqueous solution that is more alkaline than the developer to peel off the resist pattern from the substrate. The stripping solution can be, for example, an aqueous solution of NaOH or KOH with a concentration of about 2% to 5% by mass and a temperature of about 40°C to 70°C.

[0210] Unless otherwise specified, the evaluation values ​​of the above parameters are the values ​​obtained by measuring according to the measurement methods in the embodiments described later.

[0211] The embodiments of the present invention have been described above, but the present invention is not limited thereto and can be appropriately modified without departing from the spirit of the invention.

[0212] Example

[0213] Next, examples and comparative examples will be given to illustrate this embodiment in more detail. However, this embodiment is not limited to the following examples as long as it does not depart from its spirit.

[0214] <1. Preparation of photosensitive resin composition>

[0215] The compounds shown in Tables 1 and 2 were mixed to prepare photosensitive resin compositions. The values ​​in Tables 1 and 2 are the amount of solids.

[0216] It should be noted that the names of the components represented by abbreviations in Tables 1 and 2, the solvents used, etc., are shown in Tables 3 and 4.

[0217] <2. Manufacturing of Photosensitive Resin Laminates>

[0218] Acetone solvent was added to the photosensitive resin composition until the solid content reached 58% by mass. The mixture was thoroughly stirred and mixed to prepare a solution of the photosensitive resin composition. Using a rod coater, the solution of the photosensitive resin composition was uniformly coated onto a 25 μm thick polyethylene terephthalate film (Toray Industries FB-40; 16 μm polyethylene terephthalate film). The film was dried in a dryer at 95°C for 5 minutes to form a 3 μm thick photosensitive resin layer (dry film). Next, a 33 μm thick polyethylene film (TAMAPOLY GF-858) was adhered to the surface of the photosensitive resin layer to obtain a photosensitive resin laminate. The film thickness of the photosensitive resin layer was measured using a film thickness gauge (ID-C112B, Mitutoyo).

[0219] <3. Evaluation of substrate fabrication>

[0220] (laminated)

[0221] While peeling off the polyethylene film of the photosensitive resin laminate, a hot roller laminator (Asahi Kasei Electronics Co., Ltd., AL-700) is used to laminate it onto a PET substrate with a copper layer at a roller temperature of 105°C. The air pressure is set to 0.35 MPa and the lamination speed is set to 1.5 m / min.

[0222] (exposure)

[0223] The support film is peeled off, and the evaluation substrate is exposed using a chromium glass photomask and an exposure machine with an ultra-high pressure mercury lamp (parallel light exposure machine (ORC MANUFACTURING, HMW-801)).

[0224] (development)

[0225] Using a developing apparatus manufactured by Fuji Kiko, a dense conical nozzle is used to spray a 1% (w / w) Na₂CO₃ aqueous solution at 23°C for 30 seconds at a spray pressure of 0.15 MPa to dissolve and remove the unexposed portions of the photosensitive resin layer. Meanwhile, the washing process is performed using a flat nozzle at a water washing spray pressure of 0.15 MPa for the same duration as the developing process.

[0226] (Etching)

[0227] Using an etching apparatus manufactured by Fuji Kiko Co., Ltd., etching was performed under the following conditions: a spray pressure of 0.15 MPa, a temperature of 30°C, a hydrochloric acid concentration of 2% by mass, a ferric chloride concentration of 2% by mass, and a time of 60 seconds, with a dense conical nozzle.

[0228] (Stripping)

[0229] Using a stripping device manufactured by Fuji Kiko, the stripping device removes the residue by treating the sample with a 3% by mass NaOH aqueous solution for 30 seconds under conditions of a spray pressure of 0.15 MPa and a temperature of 50°C using a dense conical nozzle.

[0230] <4. Evaluation Methods>

[0231] (Image-based)

[0232] A photosensitive resin laminate with a photosensitive layer thickness of 3 μm was laminated using the method described above (lamination). After 15 minutes, the resulting evaluation substrate was exposed to a chrome glass mask with a line pattern having an exposure ratio of 1:1 to an unexposed area. Subsequently, the substrate was developed using the method described above (development) to create a resist pattern.

[0233] The minimum mask width of the normally formed cured resist line is used as the resolution value, and the resolution is graded as described below. It should be noted that the minimum mask width of normal formation is evaluated for cases where there is no tilting of the cured resist pattern or adhesion between cured resist particles.

[0234] ◎(Good): The resolution value is below 2μm.

[0235] ○ (Allowed): Resolution values ​​exceeding 2μm and below 3μm.

[0236] × (Poor): The resolution value exceeds 3μm.

[0237] (Side erosion (SE) amount)

[0238] The evaluation substrate for the side etching amount is as follows: The evaluation substrate is obtained by laminating a photosensitive resin laminate with a thickness of 3 μm onto a PET substrate with a copper layer using the method described above (lamination), and then allowing 15 minutes for the process to complete.

[0239] For this laminated evaluation substrate, after exposing a pattern with a line width / line spacing of 10 μm / 10 μm, development is performed using the method described above (development).

[0240] The width Wr (μm) of the top of the resist in the pattern was measured using an optical microscope.

[0241] Next, for the substrate having the linewidth / spacing pattern, etching is performed using an immersion method in an aqueous solution containing 2% hydrochloric acid and 2% ferric chloride at a temperature of 30°C, for a time 1.5 times the minimum etching time. Here, the minimum etching time refers to the minimum time required to completely dissolve and remove the copper foil on the substrate under the above conditions.

[0242] After the above etching, a 3% (w / w) NaOH aqueous solution was used as a stripping solution to remove the cured film on the substrate at a temperature of 50°C. The top width Wc (μm) of the obtained copper line pattern was measured using an optical microscope.

[0243] Furthermore, the lateral erosion amount is calculated using the following mathematical formula, and the lateral erosion amount is classified as described below.

[0244] Lateral erosion (μm) = (Wr - Wc) ÷ 2

[0245] ◎(Significantly good): Lateral erosion is less than 2.5 μm.

[0246] ○ (Good): Lateral erosion exceeds 2.5 μm but is less than 3.0 μm.

[0247] △ (Permissible): Lateral erosion exceeding 3.0 μm but below 3.5 μm.

[0248] × (Poor): Lateral erosion exceeds 3.5μm.

[0249] (Minimum development time)

[0250] Using the method described above (lamination), a photosensitive resin laminate with a photosensitive layer thickness of 3 μm was laminated onto a 0.4 mm thick copper-clad laminate substrate on which an 18 μm thick copper foil was laminated, to obtain a laminate. After removing the support film laminated on the photosensitive layer, a 1.0% by mass sodium carbonate aqueous solution was used for spray development at 23°C for a specified time.

[0251] Observe the surface of the substrate after development, and take the time when no development residue remains as the minimum development time, and evaluate it according to the following criteria.

[0252] ◎(Significantly good): Minimum development time is within 10 seconds.

[0253] ○ (Good): Minimum development time is within 15 seconds.

[0254] × (Defective): Minimum development time exceeds 15 seconds.

[0255] (Contrast)

[0256] Using the method described above (lamination), a photosensitive resin laminate with a photosensitive layer thickness of 3 to 10 μm is laminated onto NIKAFLEX F-30VC1 25C1 1 / 2 (manufactured by NIKKAN Industrial Co., Ltd.) to obtain a laminate.

[0257] Before exposure, the ΔE value was measured using a colorimeter (NF333, manufactured by Nippon Denshoku Kogyo Co., Ltd.) and set as 0 point. After setting the 0 point, an exposure machine equipped with an ultra-high pressure mercury lamp (parallel light exposure machine (HMW-801, manufactured by ORC MANUFACTURING Co., Ltd.)) was used at 140 mJ / cm². 2 The exposure amount is used to expose the evaluation substrate.

[0258] The ΔE value of the substrate was measured using a colorimeter 3 minutes after exposure, and the obtained ΔE value was evaluated according to the following criteria.

[0259] ◎(Significantly good): Color difference (ΔE) value is 15 or higher.

[0260] 〇 (Good): The color difference (ΔE) value is 13 or higher.

[0261] △ (Allowed A): Color difference (ΔE) value is 10 or higher.

[0262] △△ (Allowed by B): Color difference (ΔE) value is 8.0 or higher.

[0263] ×(Defective): The color difference (ΔE) value is less than 8.0.

[0264] (Exudative)

[0265] The photosensitive resin laminate (30cm × 30cm) obtained in <2. Manufacturing of Photosensitive Resin Laminate> was stored at 25°C and 55% for 7 days, and the surface was observed. It was evaluated according to the following criteria.

[0266] 〇 (Good): There are no abnormalities on the surface.

[0267] △(Permitted): Exudates are present in multiple locations on the surface.

[0268] × (Defective): Deposits are present on the entire surface.

[0269] Regarding the various embodiments and comparative examples, the evaluation results of the composition and laminate of the photosensitive resin composition are shown in Tables 1 and 2. Furthermore, the names of the components indicated by abbreviations in Tables 1 and 2, the solvents used, etc., are shown in Tables 3 and 4.

[0270] [Table 1]

[0271]

[0272] [Table 2]

[0273]

[0274] [Table 3]

[0275]

[0276] [Table 4]

[0277]

[0278] The table clearly shows that in Comparative Examples 1 and 2, which do not contain component (E), the contrast is insufficient. Furthermore, in Comparative Example 3, where the film thickness of the photosensitive resin composition layer is greater than 10 μm, the minimum development time and resolution are insufficient. It should be noted that when the film thickness is 15 μm, the resolution is poor when the development time is 30 seconds or more; therefore, the amount of lateral etching cannot be evaluated.

[0279] In contrast, in the examples containing component (E) and with a film thickness of less than 10 μm of the photosensitive resin composition layer, results with sufficiently good minimum development time, resolution, side etching (SE) amount, contrast and exudation can be obtained.

[0280] Industrial availability

[0281] By using the photosensitive resin laminate of the present invention, excellent minimum development time, resolution, lateral etching (SE) amount, contrast, and exudation are achieved, making it widely applicable as a photosensitive resin laminate for forming resist patterns or wiring patterns. Therefore, the present invention is suitable for applications such as forming lead-out wiring in the frame area of ​​a contact sensor panel, where particularly low minimum development time, resolution, lateral etching (SE) amount, contrast, and exudation are required.

Claims

1. A photosensitive resin laminate, characterized in that, It has the following characteristics: Support body; and A photosensitive resin composition layer formed on the support using a photosensitive resin composition. The photosensitive resin composition comprises the following components: (A) Alkali-soluble resins, (B) Photopolymerizable compounds with olefinic unsaturated bonds, (C) Photopolymerization initiator, (D) Compounds with increased absorbance at wavelengths of 550–700 nm, and (E) Organic color developer The film thickness of the photosensitive resin composition layer is greater than 0 and less than 10 μm. The (E) organic color developer is a photoacid generator that can produce acid by light irradiation, and is at least one compound selected from the group consisting of oxime sulfonates and triarylsulfonates.

2. A photosensitive resin laminate, characterized in that, It has the following characteristics: Support body; and A photosensitive resin composition layer formed on the support using a photosensitive resin composition. The photosensitive resin composition comprises the following components: (A) Alkali-soluble resins, (B) Photopolymerizable compounds with olefinic unsaturated bonds, (C) Photopolymerization initiator, (D) Compounds with increased absorbance at wavelengths of 550–700 nm, and (E) Organic color developer The product of the film thickness of the photosensitive resin composition layer formed on the support and the content of the (E) component relative to the total amount of the photosensitive resin composition is greater than 0 and less than 5.0, wherein the film thickness is in μm and the content is in % by mass. The (E) organic color developer is a photoacid generator that can produce acid by light irradiation, and is at least one compound selected from the group consisting of oxime sulfonates and triarylsulfonates.

3. The photosensitive resin laminate according to claim 1 or 2, wherein, The absorbance of a 0.01 mg / ml acetonitrile solution of component (E) at 330 nm or 405 nm is greater than 0.1 and less than 1.

0.

4. The photosensitive resin laminate according to claim 1 or 2, wherein, The (E) organic colorimetric agent is selected from oxime sulfonate compounds.

5. The photosensitive resin laminate according to claim 1 or 2, wherein, As component (C), it comprises loxan base dimer.

6. The photosensitive resin laminate according to claim 5, wherein, The lofenol dimer is a 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer.

7. The photosensitive resin laminate according to claim 1 or 2, wherein, As component (D), it comprises a compound having a triarylmethane skeleton.

8. The photosensitive resin laminate according to claim 7, wherein, The compound having a triarylmethane skeleton is malachite green or basic purple 3.

9. The photosensitive resin laminate according to claim 1 or 2, wherein, The weight-average molecular weight of component (A) is greater than 5,000 and less than 55,000.

10. The photosensitive resin laminate according to claim 1 or 2, wherein, The weight-average molecular weight of component (A) is 23,000 to 50,000.

11. The photosensitive resin laminate according to claim 1 or 2, wherein, The acid value of component (A) is greater than 0 mg KOH / g and less than 200 mg KOH / g.

12. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (A) is 10% to 90% by mass relative to the total amount of the photosensitive resin composition.

13. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (B) is 5% to 70% by mass relative to the total amount of the photosensitive resin composition.

14. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (B) is 30% to 50% by mass relative to the total amount of the photosensitive resin composition.

15. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (C) is 0.01% to 20% by mass relative to the total amount of the photosensitive resin composition.

16. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (D) is 0.001% to 3% by mass relative to the total amount of the photosensitive resin composition.

17. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (E) is more than 0 and less than 3.5% by mass relative to the total amount of the photosensitive resin composition.

18. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (E) is 0.5% to 0.9% by mass relative to the total amount of the photosensitive resin composition.

19. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of component (E) is greater than 0 and less than 2.5% by mass relative to the total amount of component (A).

20. The photosensitive resin laminate according to claim 1 or 2, wherein, The component (A) contains aromatic monomer components.

21. The photosensitive resin laminate according to claim 1 or 2, wherein, When the color difference before and after exposure of the resist pattern made using the photosensitive resin laminate is set as ΔE, and the thickness of the photosensitive resin composition layer is set as T [μm], a resist pattern with ΔE / T of 3.5 or more can be formed.

22. The photosensitive resin laminate according to claim 1 or 2, wherein, The film thickness of the photosensitive resin composition layer is greater than 0 and less than 10 μm.

23. A method for forming a resist pattern, comprising: A lamination process in which the photosensitive resin laminate of any one of claims 1 to 22 is laminated onto a substrate; An exposure process for exposing the laminated photosensitive resin laminate; as well as A developing process for developing the exposed photosensitive resin laminate. When the color difference of the resist pattern made using the photosensitive resin laminate before and after exposure is defined as ΔE, and the thickness of the photosensitive resin composition layer is defined as T, ΔE / T becomes 3.5 or more, where the unit of T is μm.

24. The method for forming a resist pattern according to claim 23, wherein, The color difference ΔE is greater than 10.

25. The method for forming a resist pattern according to claim 23 or 24, wherein, The exposure process utilizes the following methods: a method of exposure by direct drawing of a pattern without removing the support; or an exposure method by projecting an image of a photomask through a lens.

26. The method for forming a resist pattern according to claim 23 or 24, wherein, The exposure process uses a light source of 300-500nm.

27. The method for forming a resist pattern according to claim 23 or 24, wherein, After the exposure process, the support is peeled off and developed using an inorganic alkaline aqueous solution.

28. The method for forming a resist pattern according to claim 23 or 24, comprising: The process following the development step involves etching the substrate in areas where no pattern is configured.

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