Photosensitive resin composition, photosensitive element, method for forming resist pattern, and method for manufacturing wiring substrate

Abstract

A photosensitive resin composition containing a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, the photopolymerization initiator including a hexaaryl biimidazole compound and an N-phenylglycine compound, and the sensitizer including an anthracene compound.

Description

Technical Field

[0001] This invention relates to a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a wiring substrate. Background Technology

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

[0003] The wiring substrate is manufactured, for example, in the following sequence: First, a photosensitive layer of a photosensitive element is laminated onto a circuit forming substrate (photosensitive layer formation process). Next, a specific portion of the photosensitive layer is exposed to form a photocurable portion (exposure process). At this time, a support is peeled off before or after exposure. Then, the area of ​​the photosensitive layer other than the photocurable portion is removed from the substrate, and a resist pattern, which is a cured product of a photosensitive resin composition, is formed on the substrate (development process). Next, the obtained resist pattern is used as a resist and etched or plated to form a conductor pattern on the substrate (circuit forming process), and finally, the resist is peeled off and removed (peeling process).

[0004] Previously, exposure methods using mercury lamps as light sources and photomasks were known. More recently, a direct-drawing exposure method called LDI (Laser Direct Imaging) has emerged as a photomask-free exposure method, directly drawing digital data of a pattern onto a photosensitive layer. This direct-drawing exposure method offers better alignment accuracy and can produce high-resolution patterns compared to photomask-based exposure methods, and has therefore been introduced for fabricating high-density packaging substrates.

[0005] Generally, in the exposure process, it is desirable to shorten the exposure time to improve production efficiency. However, in the direct-draw exposure method described above, in addition to using monochromatic light such as lasers as the light source, the substrate is scanned and active light is irradiated, thus tending to require a longer exposure time compared to conventional photomask-based exposure methods. Therefore, in order to shorten the exposure time and improve production efficiency, it is necessary to further improve the sensitivity of the photosensitive resin composition.

[0006] Furthermore, in the stripping process, to improve production efficiency, it is desirable to shorten the stripping time of the resist. Therefore, a photosensitive resin composition with excellent peelability after curing is needed. Moreover, with the increasing density of wiring boards in recent years, there is also a need for photosensitive resin compositions capable of forming resist patterns with excellent resolution and adhesion.

[0007] In response to these requirements, various photosensitive resin compositions have been studied in the past. For example, Patent Document 1 discloses a photosensitive resin composition that exhibits excellent sensitivity and resolution by using a specific photosensitizer. Patent Document 2 discloses a photosensitive resin composition that exhibits excellent sensitivity and resolution by using a specific alkali-soluble polymer and a compound having ethylene double bonds.

[0008] Previous technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2009-003177

[0011] Patent Document 2: Japanese Patent Application Publication No. 2013-061556 Summary of the Invention

[0012] The technical problem to be solved by the invention

[0013] In recent years, for example, to form copper pillars connecting IC chips and wiring substrates for semiconductor packaging, there is a need for photosensitive resin compositions that can be used for thick-film applications (e.g., forming resist patterns with a thickness of 29 μm or more). Regarding the photosensitive layer formed using photosensitive resin compositions, the thicker the layer, the more difficult it is to uniformly cure it to the bottom, sometimes resulting in insufficient resolution and adhesion. Furthermore, the thicker the resist pattern, the longer the penetration time of the stripping solution, and the longer the stripping time may become. From the viewpoints of sensitivity, resolution, adhesion, and stripping properties, there is still room for further improvement in conventional photosensitive resin compositions.

[0014] The purpose of this invention is to provide a photosensitive layer resin composition with excellent sensitivity, resolution, adhesion and peelability, a photosensitive element using the photosensitive layer resin composition, a method for forming a resist pattern and a method for manufacturing a wiring substrate.

[0015] means for solving technical problems

[0016] The present invention provides the following photosensitive resin composition, photosensitive element, method for forming resist pattern and method for manufacturing wiring substrate.

[0017] [1] A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and a sensitizer, wherein,

[0018] The photopolymerization initiator contains a hexaaryl biimidazole compound and an N-phenylglycine compound, and the sensitizer contains anthracene compound.

[0019] [2] According to the photosensitive resin composition described in [1] above, wherein,

[0020] The content of the above-mentioned N-phenylglycine compound is 0.06 parts by mass or less relative to the total amount of the above-mentioned adhesive polymer and the above-mentioned photopolymerizable compound per 100 parts by mass.

[0021] [3] According to the photosensitive resin composition described in [1] or [2] above, wherein,

[0022] The aforementioned photopolymerizable compounds include (meth)acrylate compounds having an alicyclic structure.

[0023] [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein,

[0024] The aforementioned photopolymerizable compounds include polyalkylene glycol di(meth)acrylate compounds.

[0025] [5] According to the photosensitive resin composition described in [4] above, wherein,

[0026] Based on the total amount of the aforementioned photopolymerizable compounds, the content of the aforementioned polyalkylene glycol di(meth)acrylate is 8% by mass or more and 30% by mass or less.

[0027] [6] A photosensitive element comprising: a support; and a photosensitive layer formed on the support using any one of the photosensitive resin compositions described in [1] to [5].

[0028] [7] According to the photosensitive element described in [6] above, wherein,

[0029] The thickness of the aforementioned photosensitive layer is 29 μm or more.

[0030] [8] A method for forming a resist pattern, comprising: a step of forming a photosensitive layer on a substrate using any one of the photosensitive resin compositions described in [1] to [5] or the photosensitive element described in [6] or [7]; a step of photocuring a portion of the photosensitive layer; and a step of removing the uncured portion of the photosensitive layer.

[0031] [9] A method for manufacturing a wiring substrate, comprising a step of etching or plating a substrate having a resist pattern formed by the resist pattern forming method described above [8] to form a conductor pattern.

[0032] Invention Effects

[0033] According to the present invention, a photosensitive layer resin composition with excellent sensitivity, resolution, adhesion and peelability, a photosensitive element using the photosensitive layer resin composition, a method for forming a resist pattern and a method for manufacturing a wiring substrate can be provided. Attached Figure Description

[0034] Figure 1 This is a schematic cross-sectional view showing a photosensitive element according to one embodiment.

[0035] Figure 2 This is a schematic cross-sectional view illustrating a method for manufacturing a wiring board according to one embodiment. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail. In this specification, the term "process" is included not only as an independent process, but also as long as the desired effect of the process can be achieved, even if it cannot be clearly distinguished from other processes. The numerical range indicated by "~" represents a range that includes the values ​​before and after "~" as the minimum and maximum values, respectively. When viewed in a top view, the term "layer" includes structures formed on a portion of a surface, in addition to structures formed on the entire surface. "(meth)acrylic acid" refers to at least one of "acrylic acid" and its corresponding "methacrylic acid". The same applies to other similar expressions such as (meth)acrylates.

[0037] In this specification, "(poly)oxyethylidene" refers to polyoxyethylidene or polyoxyethylidene in which two or more ethylides are linked by ether bonds. "(poly)oxypropylene" refers to polyoxypropylene in which oxypropylene or polyoxypropylene in which two or more propylene groups are linked by ether bonds. "EO modified" refers to a compound containing (poly)oxyethylidene. "PO modified" refers to a compound containing (poly)oxypropylene. "EO·PO modified" refers to a compound containing (poly)oxyethylidene and / or (poly)oxypropylene.

[0038] In this specification, when multiple substances equivalent to each component are present in the composition, unless otherwise specified, the amount of each component in the composition represents the total amount of the multiple substances present in the composition. In this specification, "solid component" refers to the non-volatile component in the photosensitive resin composition after removing volatile substances. That is, "solid component" refers to components other than the solvent that remain after drying the photosensitive resin composition, and also includes components that are liquid, syrupy, or paraffinic at room temperature (25°C).

[0039] <Photosensitive Resin Composition>

[0040] The photosensitive resin composition according to this embodiment contains a binder polymer (hereinafter also referred to as "component (A)"), a photopolymerizable compound (hereinafter also referred to as "component (B)"), a photopolymerization initiator (hereinafter also referred to as "component (C)"), and a sensitizer (hereinafter also referred to as "component (D)"). Component (C) contains a hexaarylbiimidazole compound and an N-phenylglycine compound, and component (D) contains anthracene compound. The photosensitive resin composition according to this embodiment, by using this specific photopolymerization initiator and the specific sensitizer, exhibits excellent sensitivity, resolution, adhesion, and peelability, and can be appropriately used in direct painting exposure methods and thick film applications. Hereinafter, each component will be described.

[0041] (A) Composition: Adhesive polymer

[0042] The photosensitive resin composition comprises one or more of component (A). Examples of component (A) include acrylic resins, styrene resins, epoxy resins, amide resins, amide-epoxy resins, alkyd resins, and phenolic resins.

[0043] (A) From the viewpoint of alkaline developability, the composition may include acrylic resins. Acrylic resins are resins having structural units (monomer units) derived from compounds containing (meth)acryloyl groups.

[0044] Compounds containing a (meth)acrylyl group are compounds containing a (meth)acrylyl group. Examples of compounds containing a (meth)acrylyl group include hydroxyalkyl (meth)acrylates, (meth)acrylic acid, alkyl (meth)acrylates, aryl (meth)acrylates, cycloalkyl (meth)acrylates, acrylamides such as diacetone acrylamide, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, α-bromoacrylic acid, α-chloroacrylic acid, β-furfuryl (meth)acrylate, and β-styryl (meth)acrylate.

[0045] Acrylic resins can be, for example, polymers (a) having at least one selected from the group consisting of hydroxyalkyl (meth)acrylate units, (meth)acrylate units, (meth)acrylate alkyl acrylate units, and (meth)acrylate aryl acrylate units.

[0046] The hydroxyalkyl (meth)acrylate unit is a structural unit derived from hydroxyalkyl (meth)acrylates. Examples of hydroxyalkyl (meth)acrylates include methyl hydroxy(meth)acrylate, ethyl hydroxy(meth)acrylate, propyl hydroxy(meth)acrylate, butyl hydroxy(meth)acrylate, pentyl hydroxy(meth)acrylate, and hexyl hydroxy(meth)acrylate. When the alkyl portion of the hydroxyalkyl (meth)acrylate unit has 3 or more carbon atoms, it may also have a branched structure.

[0047] When polymer (a) has hydroxyalkyl (meth)acrylate units, the content of hydroxyalkyl (meth)acrylate units may be 0.5% by mass or more, 0.75% by mass or more, or 1.0% by mass or more, based on the total amount of monomer units constituting polymer (a), and may be 20% by mass or less, 15% by mass or less, or 8% by mass or less, based on the viewpoint of dispersibility.

[0048] (Meth)acrylic acid units are structural units derived from (meth)acrylic acid. When polymer (a) contains (meth)acrylic acid units, based on the total amount of monomer units constituting polymer (a), from the viewpoint of resolvability and cohesion, the content of (meth)acrylic acid units can be 1% or more by mass, 5% or more by mass, 10% or more by mass, 15% or more by mass, 20% or more by mass, or 25% or more by mass, or it can be less than 50% by mass, less than 45% by mass, less than 40% by mass, less than 35% by mass, or less than 30% by mass.

[0049] The (meth)acrylate alkyl ester unit is a structural unit derived from (meth)acrylate alkyl esters. The alkyl group of (meth)acrylate alkyl esters can be, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, or their structural isomers, and from the point of view of exfoliation, can be an alkyl group having 1 to 4 carbon atoms.

[0050] When polymer (a) has alkyl (meth)acrylate units, based on the total amount of monomer units constituting polymer (a), from the viewpoint of peelability, the content of alkyl (meth)acrylate units can be 1% or more by mass, 2% or more by mass, 3% or more by mass, or 4% or more by mass, and from the viewpoint of resolvability and adhesion, it can be 50% or less by mass, 30% or less by mass, 10% or less by mass, 8% or less by mass, or 6% or less by mass.

[0051] The (meth)acrylate aromatic unit is a structural unit derived from (meth)acrylate. Examples of (meth)acrylate aromatic esters include, for example, benzyl (meth)acrylate, phenyl (meth)acrylate, and naphthyl (meth)acrylate. When polymer (a) has (meth)acrylate aromatic units, based on the total amount of monomer units constituting polymer (a), from the viewpoint of resolvability and compatibility, the content of (meth)acrylate aromatic units can be 1% or more by mass, 5% or more by mass, 10% or more by mass, 15% or more by mass, or 20% or more by mass, or it can be less than 50% by mass, less than 45% by mass, less than 40% by mass, less than 35% by mass, less than 30% by mass, or less than 25% by mass.

[0052] The polymer (a) may also have structural units derived from monomers other than those of (meth)acryloyl groups. There may be one or more other monomers.

[0053] Other monomers include, for example, styrene or styrene derivatives, acrylonitrile, ethers of vinyl alcohol such as vinyl-n-butyl ether, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate and other monomethyl maleate, fumaric acid, cinnamic acid, α-cyanocinonic acid, itconic acid, crotonic acid and propynic acid. As styrene derivatives, examples include vinyltoluene and α-methylstyrene.

[0054] When polymer (a) has structural units derived from styrene or styrene derivatives (hereinafter also referred to as "styrene or styrene derivative units"), based on the total amount of monomer units constituting polymer (a), from the viewpoint of resolution, the content of styrene or styrene derivative units may be 40% or more by mass or 45% or more, and from the viewpoint of developability, it may be 90% or less by mass, 85% or less by mass or 80% or less.

[0055] Component (A) may contain adhesive polymers other than polymer (a), or may consist only of polymer (a). From the viewpoint of adhesion and distinguishability, based on the total amount of component (A), the content of polymer (a) in component (A) may be 50-100% by mass or 80-100% by mass.

[0056] From the viewpoint of developability, the acid value of polymer (a) can be 100 mg KOH / g or more, 120 mg KOH / g or more, 140 mg KOH / g or more, or 150 mg KOH / g or more. From the viewpoint of the adhesion (developer resistance) of the cured photosensitive resin composition, it can be 250 mg KOH / g or less, 240 mg KOH / g or less, or 230 mg KOH / g or less. The acid value of polymer (a) can be adjusted by the content of the structural units constituting polymer (a), such as (meth)acrylic acid units. When component (A) contains other adhesive polymers besides polymer (a), the acid values ​​of the other adhesive polymers can also be within the above-mentioned range.

[0057] From the viewpoint of the adhesion (developer resistance) of the cured photosensitive resin composition and the ease with which a thick film can be formed to resist etching, the weight-average molecular weight (Mw) of polymer (a) can be 10,000 or more, 15,000 or more, 20,000 or more, 25,000 or more, 30,000 or more, 35,000 or more, or 40,000 or more. From the viewpoint of developability, it can be 100,000 or less, 80,000 or less, 60,000 or less, or 50,000 or less. Regarding the dispersity (Mw / Mn) of polymer (a), it can be, for example, 1.0 or more or 1.5 or more. From the viewpoint of adhesion and resolution, it can be 3.0 or less or 2.5 or less. When component (A) includes other adhesive polymers besides polymer (a), the Mw of the other adhesive polymers can also be within the above range.

[0058] Weight-average molecular weight and dispersity can be determined, for example, by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene. More specifically, they can be determined under the conditions described in the examples. Furthermore, for compounds with low molecular weights, where it is difficult to determine the weight-average molecular weight using the methods described above, the molecular weight can be determined by other methods, and its average calculated.

[0059] Based on the total amount of solid components in the photosensitive resin composition, from the viewpoint of film formability, the content of component (A) can be 20% or more by mass, 30% or more by mass, or 40% or more by mass, and from the viewpoint of sensitivity and resolution, it can be 90% or less by mass, 80% or less by mass, 70% or less by mass, or 65% or less by mass.

[0060] From the viewpoint of membrane formability, the content of component (A) relative to the total amount of component (A) and component (B) of 100 parts by mass can be 30 or more parts by mass, 35 or more parts by mass, 40 or more parts by mass, 45 or more parts by mass, 50 or more parts by mass, or 55 or more parts by mass. From the viewpoint of sensitivity and resolution, it can be 70 or less parts by mass, 65 or less parts by mass, or 60 or less parts by mass.

[0061] (B) Components: Photopolymerizable compounds

[0062] The photosensitive resin composition comprises one or more of component (B). Component (B) may be a compound obtained by photopolymerization, for example, a compound having vinyl unsaturated bonds.

[0063] From the viewpoint of alkaline reproducibility, resolution, and peelability, component (B) may contain a bisphenol A type (meth)acrylate compound (hereinafter also referred to as "component (b1)"). Examples of component (b1) include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane. From the viewpoint of resolution and peelability, component (B) may contain 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane. Examples of 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane include 2,2-bis(4-((meth)acryloyloxypentethoxy)phenyl)propane, etc. 2,2-Bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane may be used with compounds having 10 or more oxyethylidenes, or compounds having fewer than 10 oxyethylidenes, or compounds having 10 or more oxyethylidenes and compounds having fewer than 10 oxyethylidenes may be used together.

[0064] From the perspective of the recognizable properties of the resist, based on the total amount of component (B), the content of component (b1) can be 50% or more by mass, 60% or more by mass, 70% or more by mass, 80% or more by mass, or 90% or more by mass. Component (B) may consist of only component (b1).

[0065] From the viewpoints of reproducibility, resolution, adhesion, and peelability, component (B) may also contain a polyalkylene glycol di(meth)acrylate compound (hereinafter also referred to as "component (b2)", excluding component (b1) above). Examples of component (b2) include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and EO-modified polypropylene glycol di(meth)acrylate. Component (b2) may contain EO-modified polypropylene glycol di(meth)acrylate.

[0066] From the viewpoint of reproducibility, based on the total amount of component (B), the content of component (b2) can be 8% by mass or more, 10% by mass or more, 12% by mass or more, 14% by mass or more, 16% by mass or more, 18% by mass or more, 20% by mass or more, or 22% by mass or more. From the viewpoint of peelability, adhesion, and resolution, based on the total amount of component (B), the content of component (b2) can be 8% by mass or more, 10% by mass or more, 12% by mass or more, 14% by mass or more, 16% by mass or more, or 18% by mass or more, or it can be less than 30% by mass, less than 28% by mass, less than 26% by mass, less than 24% by mass, less than 22% by mass, less than 20% by mass, or less than 19% by mass. Based on the total amount of component (B), the content of component (b2) can be from 8% by mass to 30% by mass.

[0067] From the viewpoints of sensitivity, developability, and adhesion, component (B) may also contain compounds having three or more (meth)acryloyl groups (hereinafter also referred to as "(b3)" component). Examples of component (b3) include trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO·PO-modified trimethylolpropane tri(meth)acrylate, EO-modified pentaerythritol tetra(meth)acrylate, and EO... Modified dimethylolpropane tetra(meth)acrylate, EO-modified dipentaerythritol hexa(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and tetramethylolmethane tetra(meth)acrylate. Component (b3) may include EO-modified trimethylolpropane tri(meth)acrylate. Based on the total amount of component (B), the content of component (b3) may be 5% or more by mass, 10% or more by mass, or 15% or more by mass, or less than 25% by mass, less than 20% by mass, or less than 18% by mass.

[0068] From a stripping point of view, component (B) may also contain (meth)acrylate compounds having an alicyclic structure (hereinafter also referred to as "(b4) component, excluding components (b1), (b2) and (b3) above).) Examples of component (b4) include cyclohexyl (meth)acrylate, isocamphene (meth)acrylate, adamantyl (meth)acrylate, cyclopentyl (meth)acrylate, and dicyclopentyl (meth)acrylate. Component (b4) may contain dicyclopentyl (meth)acrylate. Based on the total amount of component (B), the content of component (b4) may be 1% or more by mass, 2% or more by mass, 3% or more by mass, 5% or more by mass, or 6% or more by mass, or it may be less than 15% by mass, less than 10% by mass, or less than 8% by mass.

[0069] From the viewpoint of peelability and developability, component (B) can be used in combination with at least one component consisting of component (b2) and component (b3) and component (b4). From the viewpoint of superior peelability, component (B) can be used in combination with component (b2) and component (b4). From the viewpoint of superior sensitivity, developability, and adhesion, component (B) can be used in combination with component (b3) and component (b4). When component (b2) and component (b4) are used in combination, the mass ratio of (b2) / (b4) can be 1.5 or more, 2.0 or more, or 2.2 or more. When component (b3) and component (b4) are used in combination, the mass ratio of (b3) / (b4) can be 1.5 or more, 2.0 or more, or 2.2 or more.

[0070] The photosensitive resin composition may contain other photopolymerizable compounds as component (B) besides components (b1) to (b4) mentioned above.

[0071] Other photopolymerizable compounds include, for example, urethane monomers, nonylphenoxy polyethylene oxyacrylates, phthalic acid compounds, alkyl (meth)acrylates, and photopolymerizable compounds having at least one cationicly polymerizable cyclic ether group (such as oxobutane compounds). From the viewpoints of resolvability, adhesion, resist shape, and peelability, other photopolymerizable compounds may be at least one selected from the group consisting of urethane monomers, nonylphenoxy polyethylene oxyacrylates, and phthalic acid compounds.

[0072] Examples of nonylphenoxy polyethylene oxyacrylates include nonylphenoxy triethyleneoxy acrylate, nonylphenoxy tetraethyleneoxy acrylate, nonylphenoxy pentaethyleneoxy acrylate, nonylphenoxy hexaethyleneoxy acrylate, nonylphenoxy heptaethyleneoxy acrylate, nonylphenoxy octaethyleneoxy acrylate, nonylphenoxy nonaethyleneoxy acrylate, nonylphenoxy decaethyleneoxy acrylate, and nonylphenoxy undecaethyleneoxy acrylate.

[0073] Examples of phthalic acid compounds include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-phthalic acid (also known as 3-chloro-2-hydroxypropyl-2-(meth)acryloyloxyethyl-phthalic acid), β-hydroxyethyl-β'-(meth)acryloyloxyethyl-phthalic acid, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-phthalic acid.

[0074] When component (B) contains other photopolymerizable compounds, from the viewpoints of resolution, adhesion, resist shape and peelability, the content of other photopolymerizable compounds can be more than 1% by mass, more than 3% by mass or more than 5% by mass, or less than 25% by mass, less than 15% by mass or less than 10% by mass, based on the total amount of component (B).

[0075] In the above compounds, from the viewpoint of tightness and distinguishability, component (B) may also be included in compounds having a total of 2 to 40 oxyethylidene (EO groups) and / or oxypropylidene (PO groups) within the molecule. From the viewpoint of tightness and distinguishability, the total number of EO groups and / or PO groups may be 2 to 40 or 2 to 30.

[0076] Based on the total amount of solid components in the photosensitive resin composition, from the viewpoint of sensitivity and resolution, the content of component (B) can be 3% or more by mass, 10% or more by mass, or 25% or more by mass, and from the viewpoint of film formability, it can be 70% or less by mass, 60% or less by mass, or 50% or less by mass.

[0077] (C) Component: Photopolymerization initiator

[0078] The photosensitive resin composition may contain one or more of component (C). Component (C) includes a hexaarylbiimidazole compound and an N-phenylglycine compound. When a hexaarylbiimidazole compound is used as component (C) in the photosensitive resin composition, good resolution and resist pattern formation can be obtained, but the sensitivity may sometimes decrease. The inventors have discovered that by combining an N-phenylglycine compound with a hexaarylbiimidazole compound, excellent resolution is achieved, and sensitivity, adhesion, and peelability can be improved.

[0079] From the viewpoints of sensitivity, resolution, binding, and exfoliation, hexaarylbiimidazole compounds can be 2,4,5-triarylimidazolium dimers. Examples of 2,4,5-triarylimidazolium dimers include 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.

[0080] From the perspectives of sensitivity, resolution, adhesion, and peelability, the content of the hexaaryl biimidazole compound relative to the total amount of component (A) and component (B) of 100 parts by mass can be more than 0.1 parts by mass, more than 0.5 parts by mass, more than 1.0 parts by mass, more than 3.0 parts by mass, more than 4.0 parts by mass, or more than 4.5 parts by mass, or less than 10 parts by mass, less than 9 parts by mass, less than 8 parts by mass, less than 7 parts by mass, or less than 6 parts by mass.

[0081] Examples of N-phenylglycine compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. From the viewpoints of sensitivity, resolution, binding, and peelability, N-phenylglycine compounds may contain N-phenylglycine.

[0082] From the viewpoint of superior sensitivity, peelability, and adhesion, the content of N-phenylglycine compound relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.010 parts by mass or more, 0.015 parts by mass or more, 0.020 parts by mass or more, 0.025 parts by mass or more, 0.028 parts by mass or more, or 0.030 parts by mass or more. From the viewpoint of superior resolution, it can be 0.060 parts by mass or less, 0.055 parts by mass or less, 0.050 parts by mass or less, 0.045 parts by mass or less, 0.040 parts by mass or less, or 0.035 parts by mass or less. From the perspectives of sensitivity, resolution, adhesion, and peelability, the content of N-phenylglycine compound relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.010 parts by mass to 0.060 parts by mass, 0.015 parts by mass to 0.050 parts by mass, 0.020 parts by mass to 0.040 parts by mass, 0.025 parts by mass to 0.040 parts by mass, or 0.025 parts by mass to 0.035 parts by mass.

[0083] (C) The component may consist only of hexaaryl biimidazole compound and N-phenylglycine compound. Without impairing the effect of the present invention, it may further include photopolymerization initiators other than hexaaryl biimidazole compound and N-phenylglycine compound.

[0084] Compared to the total amount of 100 parts by mass of components (A) and (B), the content of component (C) can be more than 0.1 parts by mass, more than 0.5 parts by mass, more than 1.0 parts by mass, more than 3.0 parts by mass, more than 5.0 parts by mass, or less than 20.0 parts by mass, less than 15.0 parts by mass, less than 10.0 parts by mass, less than 8.0 parts by mass, less than 6.0 parts by mass, or less than 5.5 parts by mass.

[0085] (D) Ingredient: Sensitizer

[0086] The photosensitive resin composition contains one or more (D) components. The (D) components include anthracene compounds. The presence of anthracene compounds as (D) components in the photosensitive resin composition makes it particularly suitable for direct-painting exposure methods. Examples of anthracene compounds include, for example, 1-methylanthracene, 2-methylanthracene, 9-methylanthracene, 2-ethylanthracene, 2-butylanthracene, 9-vinylanthracene, 9-phenylanthracene, 1-aminoanthracene, 2-aminoanthracene, 9-(methylaminomethyl)anthracene, 9-acetylanthracene, 9-anthraaldehyde, 9,10-dimethylanthracene, 9,10-dimethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dipentoxyanthracene, anthracene, 9,10-di(2-ethylhexyloxy)anthracene, 2-bromo-9,10-diphenylanthracene, 9-(4-bromophenyl)-10-phenylanthracene, 10-methyl-9-anthraaldehyde, 1,4,9,10-tetrahydroxyanthracene, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, and 9,10-diethoxyanthracene. Anthracene compounds may include at least one selected from the group consisting of anthracene compounds having an aryl group and anthracene compounds having an alkoxy group. From the viewpoints of sensitivity, adhesion, resolution, and peelability, the anthracene compound may contain 9,10-dibutoxyanthracene. (D) The component may consist solely of the anthracene compound, and may also contain sensitizers other than the anthracene compound, to the extent that it does not impair the effects of the present invention.

[0087] Compared to the total amount of 100 parts by mass of components (A) and (B), the content of component (D) can be 0.20 parts by mass or more, 0.30 parts by mass or more, 0.40 parts by mass or more, 0.50 parts by mass or more, 0.55 parts by mass or more, or 0.60 parts by mass or less, or less than 1.50 parts by mass, less than 1.00 parts by mass, less than 0.80 parts by mass, less than 0.75 parts by mass or less than 0.70 parts by mass.

[0088] (Other ingredients)

[0089] The photosensitive resin composition may further contain one or more other components besides those described above. Examples of such other components include, for instance, polymerization inhibitors, hydrogen donors (bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, etc.), tribromophenyl sulfone, heat-induced color development inhibitors, plasticizers (p-toluenesulfonamide, etc.), pigments, fillers, defoamers, flame retardants, stabilizers, adhesion promoters, leveling agents, peel accelerators, antioxidants, fragrances, imaging agents, and thermal crosslinking agents. The content of these other components relative to 100 parts by weight of the total amount of components (A) and (B) may be 0.005 parts by weight or more, 0.01 parts by weight or more, or 20 parts by weight or less.

[0090] From the perspective of adjusting viscosity, the photosensitive resin composition may further contain one or more organic solvents. Examples of organic solvents include methanol, ethanol, acetone, methyl ethyl ketone, methyl celluloid, ethyl celluloid, toluene, N,N-dimethylformamide, and propylene glycol monomethyl ether.

[0091] The photosensitive resin composition can be in liquid or film form (photosensitive film). For example, the photosensitive resin composition can be used as a negative photosensitive resin composition. The photosensitive resin composition can be suitably used in the methods for forming resist patterns and manufacturing wiring substrates described later.

[0092] <Photosensitive element>

[0093] The photosensitive element according to this embodiment includes a support and a photosensitive layer formed on the support using the aforementioned photosensitive resin composition. The photosensitive element may further include a protective layer on the photosensitive layer.

[0094] Figure 1 This is a schematic cross-sectional view of a photosensitive element according to one embodiment. Figure 1 As shown, the photosensitive element 1 includes a support 2, a photosensitive layer 3 disposed on the support 2, and a protective layer 4 disposed on the photosensitive layer 3 on the opposite side of the support 2.

[0095] Examples of materials used to construct the support include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene 2,6-naphthalenedicarboxylate (PEN); and polyolefins such as polypropylene and polyethylene. From the viewpoint of easily suppressing the formation of resist defects, the support can be a polyester film or a PET film.

[0096] The haze of the support can also be 0.01–5.0%, 0.01–1.5%, 0.01–1.0%, or 0.01–0.5%. The haze can be measured using a commercially available turbidimeter according to the method specified in JIS K7105. For example, a commercially available turbidimeter such as the NDH-5000 (manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd., product name) can be used to measure the haze.

[0097] From the viewpoint of easily suppressing damage to the support during the peeling of the self-sensing layer, the thickness of the support can be 1 μm or more, 5 μm or more, or 10 μm or more. From the viewpoint of easily achieving proper exposure during exposure through the support, the thickness of the support can be 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less.

[0098] The protective layer can be a polymer film with heat and solvent resistance, such as a polyolefin film like polyethylene or polypropylene. In particular, by using a polyethylene film as the protective layer, misalignment of the photosensitive element can be suppressed, and static electricity is less likely to be generated when peeling the protective layer from the photosensitive layer, thus preventing damage to the photosensitive layer.

[0099] From the viewpoint of easily suppressing damage to the protective layer when simultaneously peeling off the protective layer and laminating the photosensitive layer and support onto the substrate, the thickness of the protective layer can be 1 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more. From the viewpoint of easily improving productivity, it can be 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less.

[0100] The thickness of the photosensitive layer after drying (after solvent evaporation) can range from 29 μm to 300 μm. From the viewpoint of forming a resist pattern with a high aspect ratio, the thickness of the photosensitive layer can be 29 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, 55 μm or more, or 60 μm or more. From the viewpoint of peelability, it can be less than 300 μm, less than 250 μm, less than 200 μm, less than 150 μm, less than 120 μm, less than 100 μm, less than 80 μm, less than 70 μm, or less than 60 μm. The thickness of the photosensitive layer can be the average of the thicknesses at 10 locations.

[0101] The photosensitive element 1 can be obtained, for example, by the following method. First, a photosensitive layer 3 is formed on the support 2. The photosensitive layer 3 can be formed, for example, by coating a photosensitive resin composition to form a coating layer and drying the coating layer. Next, a protective layer 4 is coated on the surface of the photosensitive layer 3 opposite to the support 2.

[0102] The coating layer is formed by known methods such as roller coating, comma coating, gravure coating, air knife coating, mold coating, and bar coating. The coating layer is dried, for example, at 70–150°C for about 5–30 minutes.

[0103] In another embodiment, the photosensitive element may further include other layers such as a buffer layer, an adhesive layer, a light-absorbing layer, and a gas barrier layer.

[0104] The photosensitive element 1 can be in the form of a sheet or a photosensitive element roller wound onto a core. In the photosensitive element roller, it is preferable that the photosensitive element 1 is wound into a support 2 on the outside. The core is formed, for example, of polyethylene, polypropylene, polystyrene, polyvinyl chloride, or acrylonitrile-butadiene-styrene copolymer. From the viewpoint of end-face protection, end-face separators can be provided on the end faces of the photosensitive element roller; from the viewpoint of resistance to edge melting, moisture-proof end-face separators can be provided. The photosensitive element 1 can be packaged, for example, with a black sheet with low moisture permeability.

[0105] The photosensitive element described in this embodiment can be appropriately used in the method for forming resist patterns and the method for manufacturing wiring substrates described later.

[0106] <Methods for forming resist patterns>

[0107] The method for forming a resist pattern according to this embodiment includes: a step of forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or the above-described photosensitive element (hereinafter also referred to as the "photosensitive layer forming step"), a step of photocuring a portion of the photosensitive layer (hereinafter also referred to as the "exposure step"), and a step of removing the uncured portion of the photosensitive layer (hereinafter also referred to as the "development step"), and may further include other steps as needed. Furthermore, the resist pattern is also called a photocurable pattern of the photosensitive resin composition, or a relief pattern.

[0108] (Photosensitive layer formation process)

[0109] In the photosensitive layer formation process, a photosensitive layer is formed on a substrate by using a photosensitive resin composition or a photosensitive element. There are no particular limitations on the substrate, but circuit forming substrates having an insulating layer and a conductor layer formed on the insulating layer, or die pads (lead frame substrates) such as alloy substrates are commonly used.

[0110] As a method for forming a photosensitive layer on a substrate, for example, a photosensitive layer can be formed on a substrate by removing a protective layer from a photosensitive element and then pressing the photosensitive layer of the photosensitive element onto the substrate while heating it. This results in a laminate comprising a substrate, a photosensitive layer, and a support in sequence.

[0111] From the perspective of adhesion and traceability, the photosensitive layer formation process can be carried out under reduced pressure. Heating during crimping can be performed at temperatures of 70–130°C, and crimping can be performed at a pressure of 0.1–1.0 MPa (1–10 kgf / cm²). 2 The pressure is applied, and these conditions can be selected appropriately as needed. In addition, if the photosensitive layer of the photosensitive element is heated to 70-130°C, it is not necessary to preheat the substrate. However, preheating of the substrate can be performed to further improve adhesion and tracking.

[0112] (Exposure process)

[0113] In the exposure process, the photosensitive layer can be exposed through a support and by active light, or the photosensitive layer can be exposed by active light after the support has been removed. Thus, the exposed portion, irradiated with active light, is photocured to form a photocured portion (latent image).

[0114] As an exposure method, known exposure techniques can be applied. For example, methods that irradiate active light into an image using a negative or positive mask pattern called the original image (mask exposure method), LDI exposure method (direct drawing exposure), and methods that use active light projecting an image of a photomask onto a lens to form an image (projection exposure method). The photosensitive resin composition according to this embodiment can be suitably used for direct drawing exposure.

[0115] There are no particular limitations on the source of active light, as long as it is a commonly used and known light source. For example, a light source that effectively emits ultraviolet light, such as a carbon arc lamp, a mercury vapor arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser, a solid-state laser such as a YAG laser, or a semiconductor laser such as a gallium nitride blue-violet laser. From the viewpoint of improving resolution and alignment with good balance, a light source capable of emitting I-ray monochromatic light with an exposure wavelength of 365 nm, a light source capable of emitting h-ray monochromatic light with an exposure wavelength of 405 nm, or a light source capable of emitting active light with an exposure wavelength of IHG mixed lines can be used. For example, an ultra-high pressure mercury lamp can be cited as a light source capable of emitting I-ray monochromatic light with an exposure wavelength of 365 nm. For example, a blue-violet laser diode with a wavelength of 405 nm can be cited as a light source capable of emitting h-ray monochromatic light with an exposure wavelength of 405 nm.

[0116] From the viewpoint of ensuring adhesion, in the resist pattern formation method of this embodiment, post-exposure baking (PEB) can be performed after the exposure step and before the development step. The temperature during PEB can be 50–100°C. Heating can be performed using heating devices such as hot plates, box dryers, or heated rollers.

[0117] (Developing process)

[0118] In the development process, the uncured portions of the photosensitive layer are removed from the substrate. When the photosensitive layer is exposed via a support, both the support and the uncured portions of the photosensitive layer are removed from the substrate. Through the development process, a resist pattern formed by the photocured portions obtained by photocuring the photosensitive layer is formed on the substrate. The development method can be wet development or dry development.

[0119] In the case of wet development, a developer solution corresponding to the photosensitive resin composition can be used, and development can be performed by a known wet development method. Examples of wet development methods include immersion, rotary immersion, high-pressure spraying, brushing, washing, and agitation immersion. These wet development methods can be used individually or in combination of two or more methods.

[0120] The developer is appropriately selected based on the structure of the photosensitive resin composition; for example, it can be an alkaline developer or an organic solvent developer.

[0121] From the perspective of safety, stability, and ease of operation, alkaline developers can be used as developers. Alkaline developers can be aqueous solutions containing the following salt groups: alkali hydroxides such as lithium, sodium, or potassium hydroxides; carbonates such as lithium, sodium, potassium, or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrroline salts such as sodium pyrrolineate and potassium pyrrolineate; borax; sodium metasilicate; tetramethylammonium hydroxide; ethanolamine; ethylenediamine; diethylenetriamine; 2-amino-2-hydroxymethyl-1,3-propanediol; 1,3-diamino-2-propanol; morpholine, etc.

[0122] From an environmental countermeasures perspective, inorganic alkaline developing solutions can be used. Examples of inorganic alkaline developing solutions include, for instance, a 0.1–5% by mass dilution of sodium carbonate, a 0.1–5% by mass dilution of potassium carbonate, a 0.1–5% by mass dilution of sodium hydroxide, or a 0.1–5% by mass dilution of sodium tetraborate.

[0123] The pH of the alkaline developer used for developing can be set in the range of 9 to 11, and the temperature of the alkaline developer can be adjusted according to the developability of the photosensitive layer. For example, a small amount of organic solvent, such as a surfactant, defoamer, or developer, can be mixed into the alkaline developer. Examples of organic solvents used in alkaline developers include 3-propanone alcohol, acetone, ethyl acetate, alkoxyethanol (containing alkoxy groups with 1 to 4 carbon atoms), ethanol, isopropanol, butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0124] Examples of organic solvents used in organic solvent developers include 1,1,1-trichloroethane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. From a fire prevention perspective, these organic solvents are prepared by adding water in a manner ranging from 1% to 20% by mass.

[0125] (Other processes)

[0126] The method for forming the resist pattern according to this embodiment may also include the following steps: after removing the uncured portion in the developing step, heating at 60 to 250°C or at 0.2 to 10 J / cm² is performed as needed. 2 Exposure is performed using the amount of exposure, thereby further solidifying the resist pattern.

[0127] <Manufacturing Method of Wiring Board>

[0128] The method for manufacturing a wiring substrate according to this embodiment may include the following steps: etching or plating a substrate on which a resist pattern has been formed by the above-described resist pattern forming method to form a conductor pattern (wiring layer); other steps such as a resist pattern removal step may also be included as needed.

[0129] During the etching process, the resist pattern formed on the substrate with the conductor layer is used as a mask to etch away the conductor layer of the substrate that is not covered by the resist, thereby forming the conductor pattern.

[0130] The etching method can be appropriately selected depending on the conductor layer to be removed. Examples of etching solutions include copper chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide-based etching solutions. From the viewpoint of a good etching factor, ferric chloride solution can be used as the etching solution.

[0131] In the plating process, a resist pattern formed on a substrate with a conductor layer is used as a mask to plate copper or solder onto the conductor layer of the substrate that is not covered by the resist. After the plating process, the resist is removed by removing the resist pattern as described later, and the conductor layer covered by the resist is further etched to form a conductor pattern.

[0132] As a plating process, it can be electrolytic plating or electroless plating. Examples include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-polish solder plating, nickel plating such as Watt's bath (nickel sulfate-nickel chloride) plating and nickel plating such as nickel ammonium sulfonate plating, and gold plating such as hard gold plating and soft gold plating.

[0133] After the above etching or plating process, the resist pattern on the substrate is removed. The resist pattern can be removed, for example, by using an inorganic or organic alkali stripping solution. Examples of inorganic alkali stripping solutions include 1-10% by mass aqueous solution of sodium hydroxide and 1-10% by mass aqueous solution of potassium hydroxide. Examples of organic alkali stripping solutions include amine stripping solutions such as ethanolamine, ethylenediamine, and diethylenetriamine, as well as tetramethylammonium hydroxide aqueous solution. From the viewpoint of the peelability of thick-film resist patterns, organic alkali stripping solutions can be used.

[0134] As a method for removing resist patterns, examples include immersion and spraying, which can be used alone or in combination.

[0135] After the resist pattern is removed following the plating process, the resist-coated conductor layer is further etched to form a conductor pattern, thereby enabling the manufacture of the desired wiring substrate. The etching method can be appropriately selected based on the conductor layer to be removed. For example, the aforementioned etching solution can be used.

[0136] The wiring board manufacturing method described in this embodiment can be applied not only to the manufacturing of single-layer wiring boards but also to the manufacturing of multi-layer wiring boards, and also to the manufacturing of wiring boards with small-diameter through holes, etc.

[0137] The wiring board manufacturing method described in this embodiment can be appropriately used for the manufacture of high-density packaging substrates, especially for the manufacture of wiring boards based on the semi-additive method. Furthermore, Figure 2 The diagram illustrates an example of the manufacturing process for a wiring board based on a semi-additive method.

[0138] exist Figure 2 In (a), a substrate (circuit forming substrate) on which a conductor layer 40 is formed on an insulating layer 50 is prepared. The conductor layer 40 is, for example, a copper layer. Figure 2 In (b), through the above-described photosensitive layer formation process, a photosensitive layer 30 and a support 20 are formed on the conductor layer 40 of the substrate. Figure 2 In (c), through the above-described exposure process, active light 80 is irradiated onto the photosensitive layer 30 in a desired pattern using a direct drawing exposure method and via the support 20, thereby forming a photocurable portion on the photosensitive layer 30. Figure 2 In (d), the area other than the photocurable portion formed by the above exposure process is removed from the substrate by the developing process, thereby forming a resist pattern 32 as the photocurable portion on the substrate.

[0139] exist Figure 2In (e), a plating layer 60 is formed on the conductor layer 40 of the substrate not covered by the resist by plating treatment using the photocurable portion, i.e., the resist pattern 32, as a mask. The conductor layer 40 and the plating layer 60 can be made of the same material or different materials. When the conductor layer 40 and the plating layer 60 are made of the same material, the conductor layer 40 and the plating layer 60 can be integrated.

[0140] exist Figure 2 In (f), the photocured portion, i.e., the resist pattern 32, is removed by stripping with a strong alkaline aqueous solution. For example, a 1-10% by mass sodium hydroxide aqueous solution or a 1-10% by mass potassium hydroxide aqueous solution can be used as the strong alkaline developer. Next, the conductor layer 40, which is obscured by the resist pattern 32, is removed by flash etching, and a conductor pattern 70 comprising the etched plating layer 62 and the etched conductor layer 42 is formed. The etching solution can be appropriately selected depending on the type of conductor layer 40; for example, it can be a copper chloride solution, a ferric chloride solution, an alkaline etching solution, a hydrogen peroxide etching solution, etc. By using the photosensitive element according to this embodiment, a wiring substrate with a fine conductor pattern can be fabricated.

[0141] The preferred embodiments of the present invention have been described above, but the present invention is not limited to any of the above embodiments.

[0142] Example

[0143] The present invention will be further described in detail below through embodiments, but the present invention is not limited to these embodiments.

[0144] <(A) Synthesis of Components>

[0145] Solution (a) was prepared by mixing 27 parts by mass of methacrylic acid, 5 parts by mass of methyl methacrylate, 45 parts by mass of styrene, and 23 parts by mass of benzyl methacrylate with 0.9 parts by mass of azobisisobutyronitrile (AIB). Solution (b) was prepared by dissolving 0.5 parts by mass of AIB in 50 parts by mass of a mixture (x) of acetone / propylene glycol monomethyl ether (mass ratio: 6 / 1). 500 g of the mixture (x) was added to a flask equipped with a stirrer, reflux cooler, thermometer, dropping funnel, and nitrogen inlet tube. The mixture was stirred while blowing nitrogen into the flask, and the temperature was raised to 80°C. Solution (a) was added dropwise to the mixture in the flask at a constant dropping rate over 4 hours, and the mixture was stirred at 80°C for 2 hours. Then, solution (b) was added dropwise to the solution in the flask at a constant dropping rate over 10 minutes, and the mixture was stirred at 80°C for 3 hours. Then, the solution in the flask was heated to 90°C over 30 minutes, and kept at 90°C for 2 hours. After stirring was stopped, the solution was cooled to room temperature (25°C) to obtain a solution of adhesive polymer A1. The non-volatile component (solid component) of the adhesive polymer A1 solution was 48% by mass. The weight-average molecular weight of adhesive polymer A1 was 40,000.

[0146] In addition, the weight-average molecular weight was determined by gel permeation chromatography (GPC) and derived using a calibration curve of standard polystyrene. The GPC conditions are as follows.

[0147] (GPC conditions)

[0148] Pump: Hitachi L-6000 model (manufactured by Hitachi, Ltd., product name)

[0149] Tube String: 3 in total

[0150] Gelpack GL-R420

[0151] Gelpack GL-R430

[0152] Gelpack GL-R440 (manufactured by Resonac Corporation, product name)

[0153] Eluent: Tetrahydrofuran

[0154] Measurement temperature: 40℃

[0155] Flow rate: 2.05 mL / min

[0156] Detector: Hitachi L-3300 RI (manufactured by Hitachi, Ltd., product name)

[0157] <Preparation of Photosensitive Resin Compositions>

[0158] Photosensitive resin compositions were prepared by mixing the components shown in Tables 1 and 2 at the amounts (parts by mass) shown in the tables. Furthermore, the amounts (parts by mass) of components other than the solvent shown in Tables 1 and 2 refer to the mass of non-volatile components (solid content). Details of each component shown in Tables 1 and 2 are as follows.

[0159] (Adhesive polymer)

[0160] • Polymer A1: The adhesive polymer A1 synthesized above

[0161] (Photopolymerizable compounds)

[0162] FA-321M(70): 70% solution of propylene glycol monomethyl ether of 2,2-bis(4-(methacryloyloxyethoxy)phenyl)propane (average 10 mol ethylene oxide adduct) (manufactured by Resonac Corporation).

[0163] FA-023M: PO·EO modified dimethacrylate (manufactured by Resonac Corporation, an adduct of an average of 4 mol ethylene oxide and an average of 12 mol propylene oxide (total))

[0164] FA-024M: (PO)(EO)(PO) modified dimethacrylate (manufactured by Resonac Corporation, an adduct of an average of 6 mol ethylene oxide and an average of 12 mol propylene oxide (total))

[0165] FA-137M: EO-modified trimethylolpropane trimethacrylate (average 21 mol ethylene oxide adduct, manufactured by Resonac Corporation).

[0166] UA11: EO-modified urethane methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0167] UA13: PO·EO modified urethane methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0168] FA-513AS: Dicyclopentyl acrylate (manufactured by Resonac Corporation).

[0169] FA-MECH(100): γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl phthalate (manufactured by Resonac Corporation)

[0170] (Photopolymerization initiator)

[0171] ·N-PG: N-phenylglycine

[0172] ·BCIM: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (manufactured by Hampford Company)

[0173] (Sensitizer)

[0174] • DBA: 9,10-Dibutoxyanthracene (manufactured by KAWASAKI KASEI CHEMICALS LTD.)

[0175] EAB: 4,4'-bis(diethylamino)benzophenone

[0176] (Other ingredients)

[0177] • LCV: Colorless Crystal Violet (manufactured by YAMADA CHEMICAL CO.,LTD.)

[0178] •MKG: Peacock Green (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.)

[0179] LA-7RD: 4-Hydroxy-2,2,6,6-Tetramethylpiperidine-N-oxy (manufactured by ADEKA CORPORATION)

[0180] • DIC-TBC-5P: 4-tert-butylcatechol (manufactured by DIC Corporation)

[0181] SF-808H: A mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (manufactured by SANWA KASEICORP)

[0182] (solvent)

[0183] ACS: Acetone

[0184] TLS: Toluene

[0185] MAL: Methanol

[0186] <Fabrication of Photosensitive Elements>

[0187] As a support, a 16 μm thick polyethylene terephthalate film (manufactured by TORAY INDUSTRIES, INC., product name: FB-40) was prepared. A photosensitive resin composition was coated onto the support in a manner that resulted in uniform thickness. The film was then dried sequentially using a hot air convection dryer at 80°C and 120°C to form a 40 μm thick photosensitive layer. A polyethylene film (manufactured by TAMAPOLY CO., LTD., product name: NF-15) was then laminated onto this photosensitive layer as a protective layer, resulting in a photosensitive element formed by the sequential stacking of the support, photosensitive layer, and protective layer.

[0188] <Creating Layered Bodies>

[0189] A copper-clad laminate (substrate, manufactured by Resonac Corporation, product name: MCL-E-67), comprising a glass epoxy material and copper foil (thickness: 16 μm) disposed on both sides of the glass epoxy material, was pickled and washed, and then dried with an air stream. Next, the copper-clad laminate was heated to 80°C, and the photosensitive element was laminated onto the copper-clad laminate by peeling off the protective layer while keeping the photosensitive layer in contact with the copper surface, thereby obtaining a laminate comprising a copper-clad laminate, a photosensitive layer, and a support in sequence. Lamination was performed using a 110°C hot roller at a pressing pressure of 0.4 MPa and a roller speed of 1.0 m / min.

[0190] <Evaluation>

[0191] (Minimum development time)

[0192] After cutting the aforementioned laminate into square shapes (5cm × 5cm), the support was peeled off, thus obtaining the test piece. Next, using a 1% sodium carbonate aqueous solution at 30°C and a pressure of 0.15 MPa, the unexposed photosensitive layer in the test piece was spray-developed. The shortest time at which unexposed photosensitive layers larger than 1mm were removed, as visually identifiable, was defined as the minimum development time (MD). A fully conical nozzle was used in the spray development. The distance between the test piece and the nozzle tip was 6cm, with the center of the test piece aligned with the center of the nozzle. A shorter minimum development time (in seconds) indicates better developability.

[0193] (Sensitivity)

[0194] After placing a Hitachi 41-segment trapezoidal plate on the support of the aforementioned laminate, the photosensitive layer was exposed through the support using a direct-drawing exposure machine (manufactured by Via Mechanics, Ltd., product name: DE-1UH) with a wavelength of 405nm blue-violet laser diode as the light source, with an exposure dose (irradiation energy) of 15 segments remaining on the Hitachi 41-segment trapezoidal plate. The exposure dose at this time (unit: mJ / cm²) is recorded. 2 The sensitivity (light sensitivity) was evaluated. The lower the exposure, the higher the sensitivity.

[0195] (Discrimination and fit)

[0196] Using a drawing pattern with a line width (L) / spacing width (S) of x / x (x = 3 to 30, unit: μm, 1 μm interval), the photosensitive resin layer of the above laminate was exposed to 15 segments with the number of remaining segments of the Hitachi 41-segment trapezoidal plate as the exposure amount, using a direct drawing exposure machine (manufactured by Via Mechanics, Ltd., product name: DE-1UH) with a wavelength of 405nm blue-violet laser diode as the light source.

[0197] After exposure, the support was peeled off from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1% sodium carbonate aqueous solution at 30°C for twice the minimum development time. After development, resolution was evaluated by the minimum spacing width (in μm) of the resist pattern formed where the voids (unexposed areas) were removed without residue and the lines (exposed areas) were free of bends and defects. Adhesion was evaluated by the minimum line width (in μm) of the resist pattern. For both resolution and adhesion, smaller values ​​indicate better performance.

[0198] (Peelable)

[0199] On the support of the aforementioned laminate, a glass chrome-type light tool (a light tool with a 40mm × 60mm planar pattern) was used as a negative for peel test evaluation. A direct drawing exposure machine (manufactured by Via Mechanics, Ltd., product name: DE-1UH) with a wavelength of 405nm blue-violet laser diode as the light source was used to expose the photosensitive layer through the support with an exposure amount of 15 segments, which is the number of remaining segments of the Hitachi 41-segment trapezoidal plate.

[0200] After exposure, the support was peeled off from the laminate to expose the photosensitive layer. Unexposed areas were removed by spraying a 1% (w / w) sodium carbonate aqueous solution at 30°C for twice the minimum development time, resulting in a substrate with a cured film. After the substrate was left at room temperature for 3 hours, it was immersed in an amine stripping solution heated to 50°C (6 vol% R-100S + 2 vol% R-101 aqueous solution, manufactured by MITSUBISHI GAS CHEMICAL COMPANY, INC.) and stirred at 400 rpm. The time from the start of stirring to the beginning of peeling the cured film from the substrate is defined as the peel start time (in seconds, hereinafter also referred to as "T1"), and the time when the cured film is completely removed from the substrate is defined as the peel end time (in seconds, hereinafter also referred to as "T2"). Shorter T1 and T2 values ​​indicate better peelability.

[0201] [Table 1]

[0202]

[0203] [Table 2]

[0204]

[0205] Symbol Explanation

[0206] 1-Photosensitive element, 2, 20-Support, 3, 30-Photosensitive layer, 4-Protective layer, 32-Resistant pattern, 40-Conductor layer, 42-Etched conductor layer, 50-Insulating layer, 60-Plate layer, 62-Etched plated layer, 70-Conductor pattern, 80-Active light source.

Claims

1. A photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photoinitiator, and a sensitizer, wherein, The photopolymerization initiator comprises a hexaaryl biimidazole compound and an N-phenylglycine compound. The sensitizer comprises anthracene compounds.

2. The photosensitive resin composition according to claim 1, wherein, The content of the N-phenylglycine compound is less than 0.06 parts by mass relative to the total amount of the adhesive polymer and the photopolymerizable compound (100 parts by mass).

3. The photosensitive resin composition according to claim 1, wherein, The photopolymerizable compound comprises a (meth)acrylate compound having an alicyclic structure.

4. The photosensitive resin composition according to claim 1, wherein, The photopolymerizable compound comprises a polyalkylene glycol di(meth)acrylate compound.

5. The photosensitive resin composition according to claim 4, wherein, Based on the total amount of the photopolymerizable compound, the content of the polyalkylene glycol di(meth)acrylate compound is 8% by mass or more and 30% by mass or less.

6. A photosensitive element comprising: Support body; and A photosensitive layer is formed on the support using the photosensitive resin composition according to any one of claims 1 to 5.

7. The photosensitive element according to claim 6, wherein, The thickness of the photosensitive layer is 29 μm or more.

8. A method for forming a resist pattern, comprising: The process of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 5; The process of photocuring a portion of the photosensitive layer; and The process of removing the uncured portion of the photosensitive layer.

9. A method for forming a resist pattern, comprising: The process of forming a photosensitive layer on a substrate using the photosensitive element as described in claim 6; The process of photocuring a portion of the photosensitive layer; and The process of removing the uncured portion of the photosensitive layer.

10. A method for manufacturing a wiring substrate, comprising a step of etching or plating a substrate having a resist pattern formed by the resist pattern forming method of claim 8 to form a conductor pattern.

11. A method for manufacturing a wiring substrate, comprising a step of etching or plating a substrate having a resist pattern formed by the resist pattern forming method of claim 9 to form a conductor pattern.

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