Photosensitive resin laminate, method for forming resist pattern, and method for forming wiring board

Abstract

Provided is a photosensitive resin laminate having excellent developability of a photosensitive resin layer, and excellent adhesion and resolution of a resist pattern obtained. A photosensitive resin laminate provided with a support film and a photosensitive resin layer containing a photosensitive resin composition containing the following components: (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, (C) a photopolymerization initiator, component (A) contains the following component: (A-1) a copolymer having a weight-average molecular weight of 25000 or less and containing a structural unit derived from a hydroxyalkyl (meth) acrylate, the content of the structural unit derived from a compound having an aromatic ring in component (A) being 50 mass% or more based on the total mass of all monomer components.

Description

Technical Field

[0001] This invention relates to a photosensitive resin laminate, a method for forming a resist pattern, and a method for forming a wiring board. Background Technology

[0002] In electronic devices such as printed wiring substrates, wiring patterns are generally manufactured using photolithography. In recent years, with the miniaturization and increasing density of electronic devices, photolithography is required to form finer wiring than ever before. Common manufacturing methods for wiring substrates include MSAP (Modified Semi-Additive Process) and SAP (Semi-Additive Process).

[0003] Patent Document 1 discloses a photosensitive resin composition comprising an adhesive polymer, a photopolymerizable compound, a photopolymerization initiator, and an anthracene-based sensitizer. The adhesive polymer has (meth)acrylate hydroxyalkyl ester units and styrene or styrene derivative units, and the content of the styrene or styrene derivative units is 40% by mass or more. Patent Document 1 reports that by using this photosensitive resin composition, it is possible to form resist patterns with excellent adhesion and resolution.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2021 / 193232 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In photolithography, in addition to the adhesion and resolution of the resist pattern, excellent developability of the photosensitive resin layer is also required. However, in Patent Document 1, from the viewpoint of achieving a balance between the developability of the photosensitive resin layer and the adhesion and resolution of the obtained resist pattern, and satisfying these characteristics, there is room for improvement.

[0009] Therefore, the object of the present invention is to provide a photosensitive resin laminate with excellent developability of the photosensitive resin layer, as well as excellent adhesion and resolution of the resulting resist pattern. Furthermore, the object of the present invention is to provide a method for forming a resist pattern using the photosensitive resin laminate and a method for forming a wiring board.

[0010] Solution for solving the problem

[0011] One aspect of the present invention is described below.

[0012] [File name] Scope of the claimed rights [1]

[0014] A photosensitive resin laminate comprising: a support film and a photosensitive resin layer comprising a photosensitive resin composition.

[0015] The photosensitive resin composition comprises the following components:

[0016] (A) Alkali-soluble polymers,

[0017] (B) Compounds containing olefinic unsaturated bonds

[0018] (C) Photopolymerization initiator,

[0019] The (A) component comprises the following components:

[0020] (A-1) is a copolymer containing structural units derived from (meth)acrylate hydroxyalkyl esters and having a weight-average molecular weight of less than 25,000.

[0021] The content of structural units derived from compounds having aromatic rings in component (A) is 50% by mass or more, based on the total mass of all monomeric components. [2]

[0023] According to the photosensitive resin laminate of Project 1, the proportion of the (A-1) copolymer in component (A) is 50% by mass or more. [3]

[0025] According to the photosensitive resin laminate of item 1 or 2, wherein component (B) comprises the following components:

[0026] (b1) A compound having an olefinic unsaturated bond concentration of 0.0020 mol / g or higher and having two olefinic unsaturated bonds per molecule. [4]

[0028] According to the photosensitive resin laminate of Project 3, the concentration of the olefinic unsaturated bond in component (b1) is 0.0024 mol / g or more. [5]

[0030] According to the photosensitive resin laminate of Project 3, the concentration of the olefinic unsaturated bond in component (b1) is 0.0040 mol / g or more. [6]

[0032] According to the photosensitive resin laminate of Project 3, wherein component (b1) is a di(meth)acrylate having a bisphenol A structure. [7]

[0034] According to the photosensitive resin laminate of Project 3 or 4, the content of component (b1) is 75% by mass or more based on the total amount of component (B). [8]

[0036] The photosensitive resin laminate according to any one of items 3 to 7, wherein the content of component (b1) is 90% by mass or more based on the total amount of component (B). [9]

[0038] The photosensitive resin laminate according to any one of items 3 to 8, wherein the (B) component comprises a compound represented by the following general formula (III) as the (b1) component:

[0039]

[0040] (where R is in the formula) 2 X is a methyl or hydrogen atom. 2 O represents oxyethylidene, and m3+m4 are integers from 2 to 10.

[10]

[0042] The photosensitive resin laminate according to any one of items 1 to 9, wherein the weight-average molecular weight of the (A-1) copolymer is 10.000 to 21000.

[11]

[0044] The photosensitive resin laminate according to any one of items 1 to 10, wherein the content of the structural unit having an aromatic ring in component (A) is 60% by mass or more.

[12]

[0046] The photosensitive resin laminate according to any one of items 1 to 11, wherein the content of the structural unit having an aromatic ring in component (A) is 65% by mass or more.

[13]

[0048] The photosensitive resin laminate according to any one of items 1 to 12, wherein the mass ratio of the photosensitive resin composition {total content of component (A) / total content of component (B)} is 1.30 or more.

[14]

[0050] The photosensitive resin laminate according to any one of items 1 to 13, wherein the mass ratio of the photosensitive resin composition {total content of component (A) / total content of component (B)} is 1.40 or more.

[15]

[0052] The photosensitive resin laminate according to any one of items 1 to 14, wherein the mass ratio of the photosensitive resin composition {total content of component (A) / total content of component (B)} is 1.80 or more.

[16]

[0054] The photosensitive resin laminate according to any one of items 1 to 15, wherein a protective film is provided on the side of the photosensitive resin layer opposite to the support.

[17]

[0056] The photosensitive resin laminate according to any one of items 1 to 16, wherein the thickness of the photosensitive resin layer is 1 to 20 μm.

[18]

[0058] The photosensitive resin laminate according to any one of items 1 to 17, wherein the thickness of the photosensitive resin layer is 3 to 15 μm.

[19]

[0060] The photosensitive resin laminate according to any one of items 1 to 18, wherein the thickness of the photosensitive resin layer is 5 to 10 μm.

[20]

[0062] A method for forming a resist pattern, comprising:

[0063] The process of laminating the photosensitive resin laminate as described in any one of items 1 to 19 onto a substrate;

[0064] The process of exposing the photosensitive resin layer of the laminated photosensitive resin laminate; and

[0065] The process of developing the exposed photosensitive resin layer. [twenty one]

[0067] A method for forming a wiring board, comprising:

[0068] A process of forming a resist pattern on a substrate using any one of items 1 to 19;

[0069] A process of forming conductor patterns by etching or plating a substrate with resist patterns; and

[0070] The process of peeling the resist pattern from the substrate.

[0071] The effects of the invention

[0072] According to the present invention, a photosensitive resin laminate that achieves a balance between the developability of the photosensitive resin layer and the adhesion and resolution of the resulting resist pattern can be provided, and these characteristics are satisfied. Furthermore, according to the present invention, a method for forming a resist pattern using the photosensitive resin laminate and a method for forming a wiring board can be provided. Attached Figure Description

[0073] Figure 1 This is a top view showing the structure of the mask pattern related to this embodiment.

[0074] Figure 2 This is a top view showing the structure of the mask pattern related to this embodiment.

[0075] Figure 3 This is a top view showing the structure of the mask pattern related to this embodiment. Detailed Implementation

[0076] The present embodiment will now be described. This invention is not limited to this embodiment and can be implemented in various modifications within its scope.

[0077] In this specification, when multiple structures represented by the same symbol exist in the same formula, each structure can be selected independently unless otherwise specified, and they can be the same or different. Similarly, when multiple structures represented by the same symbol exist in different formulas, each structure can be selected independently unless otherwise specified, and they can be the same or different. In this specification, unless otherwise specified, all measurements are performed based on the methods described in the embodiments. In this specification, the upper or lower limit values ​​in the numerical ranges described in stages can be replaced with the upper or lower limit values ​​in other corresponding numerical ranges described in stages, and further, can be replaced with the corresponding values ​​described in the embodiments.

[0078] In this specification, "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid," "(meth)acrylate" means "acrylate" and / or "methacrylate," and "(meth)acryloyl" means "acryloyl" and / or "methacryloyl." "Compounds containing (meth)acryloyl" are, for example, referred to as "(meth)acrylate compounds." In this specification, the term "process" is included not only when it is an independent process but also when it cannot be clearly distinguished from other processes, as long as it achieves the function of that process. In the accompanying drawings, for further clarity, scale bars, shapes, and lengths are sometimes exaggerated. In this specification, "solid components" of the photosensitive resin composition refers to components other than the solvent in the photosensitive resin composition.

[0079] It should be noted that, unless otherwise specified, in any given method:

[0080] "Adhesion" refers to the adhesion performance between the resist pattern and the substrate;

[0081] "Resolution" refers to the resolution performance of the resist pattern;

[0082] "Developability" refers to the developability of the unexposed portion of the photosensitive resin layer (resist).

[0083] [Photosensitive resin laminate]

[0084] The photosensitive resin laminate of this embodiment includes:

[0085] Support film and photosensitive resin layer comprising photosensitive resin composition,

[0086] The photosensitive resin composition comprises the following components:

[0087] (A) Alkali-soluble polymers,

[0088] (B) Compounds containing olefinic unsaturated bonds

[0089] (C) Photopolymerization initiator,

[0090] The (A) component comprises the following components:

[0091] (A-1) is a copolymer containing structural units derived from (meth)acrylate hydroxyalkyl esters and having a weight-average molecular weight of less than 25,000.

[0092] The content of structural units derived from compounds having aromatic rings in component (A) is 50% by mass or more, based on the total mass of all monomeric components.

[0093] The high content of structural units derived from compounds with aromatic rings in component (A) readily ensures good adhesion, for example. However, in this case, further research is needed to ensure good properties for various characteristics other than adhesion (e.g., developability). In this regard, the presence of structural units derived from compounds with hydroxyl groups (especially hydroxyalkyl (meth)acrylates) in component (A) is considered advantageous, for example, in terms of resolution; however, achieving a balance of various properties and satisfying these properties remains difficult in the prior art.

[0094] In this embodiment, based on controlling the content of structural units derived from compounds having aromatic rings in component (A) to be 50% by mass or more, component (A) comprises the following components:

[0095] (A-1) is a copolymer containing structural units derived from compounds having hydroxyl groups (especially hydroxyalkyl (meth)acrylates) and having a weight-average molecular weight of 25,000 or less. This embodiment intentionally uses such a low molecular weight (A-1) copolymer from the viewpoint of achieving a balance of various properties and satisfying these properties. Furthermore, in this embodiment using such an (A-1) copolymer, various properties are more easily ensured by controlling the composition and / or amount of component (B) in a specific manner.

[0096] In this specification, the compound containing hydroxyl groups in the (A-1) copolymer is (meth)acrylate hydroxyalkyl ester.

[0097] For example, from the viewpoint of improving the adhesion and resolution of the photosensitive resin layer, measures that can be easily implemented to increase the crosslink density during exposure can be cited, such as increasing the concentration of olefinic unsaturated bonds in component (B). Regarding this, the use of alkali-soluble polymers with high weight-average molecular weights as the alkali-soluble polymers is generally advantageous for improving the flexibility (bending resistance) of the resulting photosensitive resin layer after exposure.

[0098] That is, when attempting to achieve a balance between adhesion, resolution, and developability by using a large amount of low-molecular-weight alkali-soluble polymers, and further attempting to increase the concentration of olefinic unsaturated bonds in component (B) to improve adhesion and resolution, there is a tendency for the softness (bending resistance) of the photosensitive resin layer to deteriorate after exposure.

[0099] On the other hand, in a preferred embodiment of this invention, by designing a photosensitive resin composition using a large amount of the specified (B) component (as described later, a difunctional monomer in the (B) component that easily increases the crosslinking density during exposure), it is possible to increase the crosslinking density after exposure, and obtain a soft cured film by the linear crosslinking of the (B) components with each other. Softness is easily ensured even when using a low molecular weight alkali-soluble polymer.

[0100] This embodiment includes at least a support film and a photosensitive resin layer comprising a photosensitive resin composition. In addition to the support film and the photosensitive resin layer, the photosensitive resin laminate may also include other layers. Examples of other layers include an intermediate layer disposed between the support film and the photosensitive resin layer, a protective film disposed on the side of the photosensitive resin layer opposite to the support film, and a release layer disposed between the protective film and the photosensitive resin layer.

[0101] The photosensitive resin laminate is constructed, for example, by directly laminating a photosensitive resin layer onto a support film, or by laminating it onto a support film with an intermediate layer in between. The photosensitive resin layer can be one layer or two or more layers. From the viewpoint of easily and significantly achieving the effects of this embodiment, the photosensitive resin laminate is preferably a dry film resist or a transfer film, more preferably a dry film resist.

[0102] <Supporting membrane>

[0103] The support film is a layer or film used to support the photosensitive resin layer, and is preferably a transparent substrate that allows active light to pass through. Examples of transparent substrates include synthetic resins such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate. Polyethylene terephthalate (PET) is preferred because it has moderate flexibility and strength. From the viewpoint of easily ensuring adhesion, the absorbance of the support film at a wavelength of 365 nm is preferably 0.3 or less, more preferably 0.2 or less, further preferably 0.1 or less, and most preferably 0.08 (e.g., 0.080) or less. The absorbance can be 0 or more.

[0104] As the support film, a film with few internal foreign matter, i.e., a high-quality film, is preferred. Specifically, as a high-quality film, PET films synthesized using Ti-based catalysts, PET films with small diameters and low content of lubricant, PET films containing lubricant only on one side of the film, thin-film PET films, PET films that have undergone smoothing treatment on at least one side, and PET films that have undergone roughening treatment such as plasma treatment on at least one side are more likely to be used. As a result, it is easier for exposed light to reach the photosensitive resin layer without being blocked by internal foreign matter, thus easily improving the resolution of the photosensitive resin laminate.

[0105] The thickness of the support film is preferably 5 to 25 μm, more preferably 6 to 20 μm. A thinner support film tends to have fewer internal foreign matter, thus making it easier to prevent a decrease in resolution. On the other hand, if the film thickness is less than 5 μm, elongation deformation in the winding direction due to tension is easily generated during the coating and / or winding manufacturing process, and cracks caused by minor damage are also easily generated. As a result, the film strength is often insufficient, and wrinkles are easily generated during lamination. At least one side of the support film can be smoothed using a calendering apparatus or the like. This reduces the surface roughness of one side of the support film, particularly the side in contact with the photosensitive resin layer, thus facilitating the application of the effects of the present invention.

[0106] From the viewpoint of improving the parallelism of light irradiating the photosensitive resin layer and from the viewpoint of obtaining high resolution, the haze of the support film is preferably 0.01 to 1.5%, more preferably 0.01 to 1.2%, and even more preferably 0.01 to 0.95%.

[0107] <Photosensitive resin layer>

[0108] The photosensitive resin layer comprises a photosensitive resin composition. The photosensitive resin composition comprises "(A) an alkali-soluble polymer," "(B) a compound having an olefinically unsaturated bond," and "(C) a photopolymerization initiator." The photosensitive resin composition may also include "(D) a polymerization inhibitor." In this specification, the above (A) to (D) are sometimes simply referred to as "(A) component" to "(D) component." Components (A) to (D), or raw materials of these components, may be used individually or in combination of two or more. Furthermore, regarding optional components (other components), when included, they may be used individually or in combination of two or more.

[0109] The thickness of the photosensitive resin layer is preferably 3 to 100 μm, with specific preferred thicknesses including 7 μm, 15 μm, 25 μm, 40 μm, and 60 μm. A more preferred upper limit is 50 μm. The closer the thickness is to 3 μm, the easier it is to improve resolution; the closer it is to 100 μm, the easier it is to improve film strength. When the formed resist pattern is used in a plating process, the film thickness is preferably 10 to 30 μm, more preferably 15 to 25 μm. To better suit the miniaturization of wiring, the film thickness is preferably 3 to 20 μm or 5 to 15 μm. In other words, the film thickness is preferably 1 to 20 μm, 3 to 15 μm, or 5 to 10 μm.

[0110] (A) Components: Alkali-soluble polymer

[0111] Component (A) has the (A-1) copolymer described later. Component (A) may also have copolymers other than the (A-1) copolymer (other copolymers), which preferably have repeating units formed by at least one of the first monomers described later, and more preferably have repeating units formed by at least one of the first monomers and at least one of the second monomers described later.

[0112] The first monomer is a monomer having a carboxyl group and at least one olefinic unsaturated bond in its molecule. Examples of the first monomer include (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, 4-vinylbenzoic acid, and maleic acid half ester. Among these, (meth)acrylic acid is preferred from the viewpoint of excellent adhesion and resolution, and methacrylic acid is more preferred.

[0113] (A) Of the components, the content of the first monomer, based on the total mass of all monomer components, is preferably 10 to 50% by mass. From the viewpoint of excellent developability and resolution, it is preferable that this content is 10% by mass or more. From the same viewpoint, this content is more preferably 15% by mass or more, further preferably 18% by mass or more, even more preferably 21% by mass or more, particularly preferably 23% by mass or more, and most preferably 25% by mass or more. From the viewpoint of excellent adhesion and flexibility, it is preferable that this content is 50% by mass or less. From the same viewpoint, this content is more preferably 35% by mass or less, further preferably 30% by mass or less, particularly preferably 29% by mass or less, and most preferably 27% by mass or less. When using two or more first monomers, it is preferable that the total content of each is within the above range.

[0114] The second monomer is a non-acidic monomer having at least one olefinic unsaturated bond in its molecule. The content of the second monomer in component (A) is preferably 50 to 90% by mass, based on the total mass of all monomer components. In one embodiment, this content can be understood as the content of the monomer other than the first monomer in component (A).

[0115] Component (A) contains a compound with an aromatic structure as a second monomer. By giving component (A) a structural unit derived from this compound, the swelling of the photosensitive resin layer during development can be easily suppressed, thus enabling the production of a photosensitive resin layer with excellent adhesion and resolution.

[0116] (A) The content of structural units derived from compounds having aromatic structures in the component is 50% by mass or more, based on the total mass of all monomer components. This results in excellent adhesion and resolution. From the same viewpoint, this content is more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more. Furthermore, from the viewpoint of excellent developability, this content is preferably 85% by mass or less, and from the same viewpoint, more preferably 80% by mass or less. When using two or more compounds having aromatic structures as the second monomer, the total content of structural units derived from each compound is preferably within the above-mentioned range.

[0117] Examples of compounds having an aromatic structure include benzyl (meth)acrylate, styrene, styrene derivatives (methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, styrene dimers and styrene trimers, etc.), phenoxyethyl (meth)acrylate, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl (meth)acrylate. Among these, benzyl (meth)acrylate and / or styrene are preferred as compounds having an aromatic structure, and styrene is more preferred. From the viewpoint of excellent adhesion and resolution, the styrene content is preferably 10-85% by mass, more preferably 30-70% by mass, and even more preferably 40-60% by mass, based on the total mass of all monomer components.

[0118] The compound having an aromatic structure preferably includes both styrene and benzyl (meth)acrylate. Regarding the content of benzyl (meth)acrylate, whether used in combination with styrene or not, it is preferably 1 to 60% by mass, more preferably 5 to 50% by mass, and even more preferably 10 to 35% by mass, based on the total mass of all monomer components.

[0119] In this embodiment, component (A) comprises the following components:

[0120] (A-1) is a copolymer containing structural units derived from compounds having hydroxyl groups (especially hydroxyalkyl (meth)acrylate) and having a weight-average molecular weight of 25,000 or less. This allows for the production of photosensitive resin layers with excellent developability and resolution.

[0121] In this embodiment, component (A) comprises a relatively large number of structural units derived from compounds having aromatic rings. From the viewpoint of achieving a balance and satisfying various properties, the aforementioned copolymer (A-1) was selected. That is, according to this embodiment, by obtaining the contribution of "structural units derived from compounds having aromatic rings" (e.g., excellent adhesion), and by selecting the aforementioned copolymer (A-1), a balance can be achieved between the developability of the photosensitive resin layer and the adhesion and resolution of the resulting resist pattern, thus satisfying these properties.

[0122] The structural units derived from hydroxyl-containing compounds in the (A-1) copolymer can originate from the first monomer, or alternatively, from the second monomer. However, from the viewpoint of easily realizing the (A-1) copolymer, it is preferable that the second monomer comprises a hydroxyl-containing compound. The second monomer can comprise both compounds with aromatic structures and compounds with hydroxyl groups.

[0123] In addition, in component (A), if other copolymers other than copolymer (A-1) are included, structural units derived from compounds having hydroxyl groups may also be included in the other copolymers.

[0124] The aforementioned compounds containing hydroxyl groups are compounds with alcoholic hydroxyl groups, particularly hydroxyalkyl (meth)acrylates. An alcoholic hydroxyl group refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Among these, 2-hydroxyethyl methacrylate is preferred. These are readily available, and the developability of the photosensitive resin layer is easily controlled, allowing for the creation of resist patterns with excellent adhesion and resolution.

[0125] From the viewpoint of excellent developability and adhesion, the content of the hydroxyl-containing compound in component (A) is preferably 1.0 to 20% by mass, more preferably 1.0 to 10% by mass, and even more preferably 1.0 to 6.0% by mass, based on the total mass of all monomeric components. When using two or more compounds containing hydroxyl-containing compounds, it is preferable that the total content of each is within the above range.

[0126] The second monomer may further include polymeric compounds that are different from compounds with aromatic structures and compounds with hydroxyl groups.

[0127] Examples of polymeric compounds that differ from compounds with aromatic structures and compounds with hydroxyl groups include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenoxyethyl methacrylate, isobornyl methacrylate, and nonyl methacrylate. Phenoxy polyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol (meth)acrylate, methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)-methyl (meth)acrylate, cyclotrimethylolpropane methyl acetal (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, and other (meth)acrylate esters; vinyl acetate and other vinyl alcohol esters; and (meth)acrylonitrile, etc.

[0128] Component (A) may be a copolymer different from copolymer (A-1). Copolymer different from copolymer (A-1) may have a higher weight-average molecular weight than copolymer (A-1), a lower weight-average molecular weight than copolymer (A-1), or the same weight-average molecular weight.

[0129] The weight-average molecular weight of component (A) is preferably 10,000 or more and less than 30,000. From the viewpoint of achieving a balance between adhesion, resolution, and developability, and satisfying these characteristics, a weight-average molecular weight of less than 30,000 is preferred. As shown in one embodiment of this method, a weight-average molecular weight of 30,000 for component (A) does not yield satisfactory results for some of the characteristics evaluated in the embodiment. A weight-average molecular weight of 20,000 for component (A) satisfies some of the characteristics evaluated in the embodiment. In terms of achieving a low molecular weight for component (A), a weight-average molecular weight of component (A) is more preferably a value between 20,000 and 30,000 or less, i.e., 25,000 or less. Furthermore, a weight-average molecular weight of component (A) is further preferably 23,000 or less, and particularly preferably 21,000 or less. It should be noted that, from the viewpoint of preventing the leaching of the resist pattern in the water washing process after development, the weight average molecular weight of component (A) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 17,000 or more.

[0130] (A) The polydispersity of the component is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, even more preferably 1.0 to 4.0, and particularly preferably 1.0 to 3.0.

[0131] In this embodiment, component (A) may contain only one copolymer or two or more copolymers. When component (A) contains only one copolymer, the copolymer is (A-1) copolymer, and the content of each structural unit is the proportion of the compound constituting each structural unit. When component (A) contains two or more copolymers, the content of each structural unit is expressed as a weighted average of the proportions of the compounds constituting each structural unit, obtained by weighting the proportions of the contents of each copolymer. When component (A) contains two or more copolymers, it is preferable to select the molecular weight and polydispersity such that the weighted average obtained by weighting the proportions of the contents of each copolymer falls within the aforementioned range.

[0132] (A) The synthesis of the component is preferably carried out by adding an appropriate amount of a free radical polymerization initiator such as benzoyl peroxide or azoisobutyronitrile to a solution prepared by diluting the single or multiple monomers described above with solvents such as acetone, methyl ethyl ketone, or isopropanol, and then heating and stirring. Sometimes, a portion of the mixture is added dropwise to the reaction solution while the synthesis is being carried out. After the reaction is complete, solvent is sometimes added to adjust the concentration to the desired level. As a synthesis method, in addition to solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization can also be used. In addition, synthesis is sometimes carried out by living radical polymerization.

[0133] The content of component (A) relative to the total solids content of the photosensitive resin composition can be 40% by mass or more, preferably 50% by mass or more, and more preferably 55% by mass or more. Alternatively, this content can be 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0134] From the viewpoint of controlling the development time, it is preferable to set the content of component (A) to 90% by mass or less relative to the total solid content of the photosensitive resin composition. From the viewpoint of suppressing the seepage of the photosensitive resin layer from the end face of the film and to appropriately exhibit the effect exerted by component (A), it is preferable to set it to 40% by mass or more.

[0135] (A-1) copolymer

[0136] The photosensitive resin composition of this embodiment includes the above-mentioned (A-1) copolymer as component (A). The (A-1) copolymer may contain only one copolymer or two or more copolymers, as long as it is a copolymer containing structural units derived from compounds having hydroxyl groups (especially hydroxyalkyl (meth)acrylates) and having a weight average molecular weight of 25,000 or less.

[0137] From the viewpoint of excellent developability and resolution, it is preferable that the weight-average molecular weight of the (A-1) copolymer is 25,000 or less. From the same viewpoint, this weight-average molecular weight is preferably 23,000 or less, more preferably 21,000 or less. Furthermore, from the viewpoint of suppressing the seepage of the photosensitive resin layer from the film end face, this weight-average molecular weight is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 18,000 or more. The (A-1) copolymer has repeating units formed from at least one of the first monomers and at least one of the second monomers described above.

[0138] The (A-1) copolymer may contain the substance described in "(A) component: alkali-soluble polymer" as the first monomer, wherein (meth)acrylic acid is preferably included. The proportion of the first monomer in the (A-1) copolymer is preferably 10 to 50% by mass, based on the total mass of all monomer components. From the viewpoint of excellent developability and resolution, this proportion is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 18% by mass or more, even more preferably 21% by mass or more, particularly preferably 23% by mass or more, and most preferably 25% by mass or more. From the viewpoint of excellent adhesion and resolution, this content is preferably 50% by mass or less, more preferably 35% by mass or less, further preferably 30% by mass or less, particularly preferably 29% by mass or less, and most preferably 27% by mass or less. When using two or more first monomers, the total content of each is preferably within the above range.

[0139] The (A-1) copolymer contains a compound having hydroxyl groups as a second monomer. By including structural units derived from compounds having hydroxyl groups, it exhibits excellent reproducibility and resolution. The compound having hydroxyl groups is a compound containing alcoholic hydroxyl groups, particularly hydroxyalkyl (meth)acrylates. Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Among these, 2-hydroxyethyl methacrylate is particularly preferred.

[0140] From the viewpoint of excellent developability and adhesion, the proportion of hydroxyl-containing compounds in the (A-1) copolymer is preferably 1.0 to 20% by mass, more preferably 1.0 to 10% by mass, and even more preferably 1.0 to 6.0% by mass, based on the total mass of all monomer components. When using two or more compounds containing hydroxyl-containing compounds, the total proportion of each is preferably within the above range.

[0141] The (A-1) copolymer preferably contains a compound having an aromatic structure as a second monomer. Because the (A-1) copolymer has structural units derived from this compound, swelling of the photosensitive resin layer during development is easily suppressed; therefore, a photosensitive resin layer with excellent adhesion and resolution is readily obtained. Examples of compounds having an aromatic structure include those described in "(A) component: alkali-soluble polymer" above, wherein benzyl (meth)acrylate and / or styrene are preferred.

[0142] From the viewpoint of suppressing the swelling of the resist pattern in the developer after exposure, thereby achieving good resolution and adhesion, the proportion of structural units derived from compounds having aromatic structures in the (A-1) copolymer is preferably 50 to 90% by mass, more preferably 55 to 80% by mass, and even more preferably 60 to 75% by mass, based on the total mass of all its monomer components. When using two or more compounds containing compounds having aromatic structures, the total copolymerization ratio of each is preferably within the above range.

[0143] When component (A) contains copolymers other than copolymer (A-1), these other copolymers may contain compounds having aromatic structures. That is, compounds having aromatic structures may be contained in copolymer (A-1), in other copolymers, or in both. When component (A) contains other copolymers, the content of structural units derived from compounds having aromatic rings in component (A) is 50% by mass or more, based on the total mass of all monomer components. It should be noted that when component (A) contains other copolymers, these other copolymers may be one or more.

[0144] From the viewpoint of properly maximizing the effects of this embodiment, the content of the (A-1) copolymer relative to the total amount of component (A) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and may also be 100% by mass. Similarly, from the viewpoint of the total solids content in the photosensitive resin composition, the content of the (A-1) copolymer is preferably 20 to 90% by mass, more preferably 25 to 70% by mass, and even more preferably 30 to 60% by mass.

[0145] (B) Components: Compounds containing olefinic unsaturated bonds

[0146] Component (B) is a compound having at least one olefinic unsaturated bond per molecule. From the viewpoint of excellent sensitivity, viscosity, and followability, the content of component (B) relative to the total solids content of the photosensitive resin composition is preferably 30% by mass or more, more preferably 35% by mass or more. Furthermore, from the viewpoint of excellent edge melting, viscosity, and resolution, this content is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 42% by mass or less. Edge melting refers to the amount of resist spillage when the photosensitive element is stored in a roll; less spillage is preferred. Viscosity refers to the adhesiveness of the photosensitive resin composition. To suppress poor lamination to the substrate, and to suppress poor peeling of the protective film and the support film, the adhesiveness of the photosensitive resin composition is preferably moderate.

[0147] In this embodiment, from the viewpoint of giving the exposed photosensitive resin layer moderate flexibility and excellent bending resistance, the photosensitive resin composition preferably includes a compound having two olefinic unsaturated bonds per molecule as component (B). Furthermore, from the viewpoint of excellent crosslinking efficiency during the exposure process, the photosensitive resin composition may further include a compound having three olefinic unsaturated bonds per molecule, or may further include a compound having four, five, or six olefinic unsaturated bonds per molecule.

[0148] From the viewpoint of excellent peelability, resolution, and adhesion, the content of the compound having two olefinic unsaturated bonds per molecule, based on the total amount of component (B), is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 90% by mass or more. This content can be 100% by mass.

[0149] In the case of compounds containing three or more olefinic unsaturated bonds, from the viewpoint of improving the crosslinking efficiency in the exposure process and thereby improving the adhesion, the content of compounds containing three or more olefinic unsaturated bonds, based on the total amount of component (B), can be 1 to 50% by mass, 1 to 25% by mass, or 1 to 15% by mass.

[0150] Preferably, component (B) contains a compound comprising a (meth)acryloyl group (hereinafter referred to as a (meth)acrylate compound). Regarding component (B), a "(meth)acrylate compound having n (meth)acryloyl groups in one molecule" is referred to as "n-functional." For example, regarding component (B), having 1, 2, 3, 4, 5, or 6 olefinic unsaturated bonds in one molecule is referred to as "monofunctional," "difunctional," "trifunctional," "quadrifunctional," "pentafunctional," or "hexafunctional," respectively.

[0151] Examples of difunctional (meth)acrylate compounds include alkyl di(meth)acrylates, 1,3-bis(meth)acryloyloxy-2-propanol, polyalkylene glycol di(meth)acrylates, and di(meth)acrylates having a bisphenol A structure. Here, "bisphenol A structure" includes the concept of hydrogenated bisphenol A structure.

[0152] Examples of polyalkylene glycol di(meth)acrylates include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and compounds represented by the following general formula (I):

[0153]

[0154] (where R is in the formula) 1 Each is independently a hydrogen atom or a methyl group, X 1O and Y 1 O is independently oxoethylidene or oxopropylidene, (X 1 O) m1 、(X 1 O) m2 、(Y 1 O) n1 It is a (poly)oxyethylene chain or a (poly)oxypropylene chain, where m1, m2, and n1 are each independent integers from 0 to 40, m1+m2 is from 1 to 40, and n1 is from 1 to 20.

[0155] Examples of di(meth)acrylates having a bisphenol A structure include compounds represented by general formula (II):

[0156]

[0157] (where R is in the formula) 2 Each is independently a hydrogen atom or a methyl group, X 2 O and Y 2 Each of O is independently oxoethylidene or oxopropylidene, m3, m4, n2, and n3 are independently integers from 0 to 40, m3+m4 is from 1 to 40, and n2+n3 is from 0 to 20.

[0158] From the viewpoint of resolution and tightness, the average value of n2+n3+m3+m4 in the di(meth)acrylate compound having a bisphenol A structure represented by general formula (II) is preferably 20 or less, more preferably 10 or less. The average value of n2+n3+m3+m4 can be 2 or more. It should be noted that the number of repeating units of oxyethylidene or oxypropylene is expressed as an integer value in a single molecule, and as a rational number as an average value in an aggregate of multiple molecules.

[0159] In addition, di(meth)acrylates having the structure of hydrogenated bisphenol A can be listed as compounds obtained by adding hydrogen to the aromatic ring of the compound represented by formula (II).

[0160] As a polyalkylene glycol di(meth)acrylate represented by formula (I), R can be cited as an example. 1 =Methyl group, m1+m2=6 (average value), n1=12 (average value), X 1 O represents oxyethylidene, Y represents... 1 O represents vinyl compounds with an oxypropylidene group (manufactured by Hitachi Chemical Industry Co., Ltd., product name "FA-024M"), etc.

[0161] As di(meth)acrylate compounds having a bisphenol A structure as represented by general formula (II), BPE-200(R) can be listed as an example. 2 =Methyl, X 2O = oxyethylidene, m3 + m4 = 4, n2 = n3 = 0), BPE-500(R) 2 =Methyl, X 2 O = oxyethylidene, m3+m4=10, n2=n3=0), BPE-900(R) 2 =Methyl, X 2 O = oxyethylidene, m3+m4=17, n2=n3=0 (the above are product names manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), FA-321M(R) 2 =Methyl, X 2 O = oxyethylidene, m3 + m4 = 10, n2 = n3 = 0), FA-P321M(R) 2 =Methyl, X 2 O = oxypropylidene, m3+m4=10, n2=n3=0 (the above are product names manufactured by Resonac Company), etc.

[0162] Commercially available difunctional (meth)acrylate compounds include, for example, NK Ester (registered trademark) A-HD-N, NK Ester A-NOD-N, NK Ester A-DOD-N, NK Ester A-NPG, NK Ester 701A, NK Ester A-200, NK Ester A-400, NK Ester A-600, NK Ester A-1000, NK Ester APG-200, NK Ester APG-400, NK Ester APG-700, NK Ester A-PTMG65, NK Ester A-DCP, NK Ester ABE-300, NK Ester A-BPE-4, NK Ester A-BPE-10, NK Ester A-BPE-20, NK Ester HD-N, NK Ester NOD-N, NK Ester DOD-N, NK Ester NPG, NK Ester 701, NK Ester 2G, and NK Ester... 3G, NK Ester 4G, NK Ester 9G, NK Ester 14G, NK Ester 23G, NK Ester 9PG, NK Ester DCP, NK Ester BPE-80N, NK Ester BPE-100, NK Ester BPE-200, NK Ester BPE-500, NK Ester BPE-900, NK Ester BPE-1300N, NK Oligo (registered trademark) UA-4200, NK Oligo UA-160TM, NK Oligo UA-290TM, NK Oligo UA-W2A, NK Oligo UA-4400, NK Oligo UA-122P, NK Oligo U-200PA (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Light Acrylate (registered trademark) 3EG-A, Light Acrylate 4EG-A, Light Acrylate 9EG-A, Light Acrylate 14EG-A, Light AcrylatePTMGA-250, Light Acrylate NP-A, Light Acrylate MPD-A, Light Acrylate 1.6HX-A, Light Acrylate 1.9ND-A, Light Acrylate DCP-A, Light Acrylate BP-4EAL, Light Acrylate BP-4PA, Light Acrylate HPP-A, Light Ester G-201P (the above are manufactured by Kyeisha Chemical Co., Ltd.), FANCRYL (registered trademark) FA-124AS, FANCRYL FA-023M, FANCRYL FA-121M, FANCRYL FA-124M, FANCRYL FA-125M, FANCRYL FA-129AS, FANCRYL FA-137M, FANCRYL FA-220M, FANCRYL FA-222A, FANCRYL FA-240A, FANCRYL FA-240M, FANCRYL FA-320M, FANCRYL FA-3218M, FANCRYL FA-321A, FANCRYL FA-321M, FANCRYL FA-324A, FANCRYL FA-731A, FANCRYL FA-P240A, FANCRYL FA-P270A, FANCRYL FA-PTG9A, FANCRYL FA-PTG9M, FANCRYL FA-PTG28A, FANCRYL FA-PTG49A (all manufactured by Resonac), DPGDA, HDDA, TPGDA, EBECRYL 145, EBECRYL 150, PEG400DA, EBECRYL 11, IRR 214-K, EBECRYL 130, EBECRYL PEG200DMA (all manufactured by DAICL-ALLNEX LTD).(Manufactured by Arkema), SR212, SR213, SR230, SR238F, SR259, SR268, SR272, SR306H, SR344, SR349, SR508, CD560, CD561, CD564, SR601, SR602, SR610, SR833S, SR9003, SR9045, SR9209, SR205, SR206, SR209, SR210, SR214, SR231, SR239, SR248, SR252, SR297, SR348, SR480, CD540, CD541, CD542, SR603, SR644, SR9036 (all manufactured by Arkema), KAYARAD (registered trademark) NPGDA, KAYARAD PEG400DA, KAYARAD FM-400, KAYARAD R-167, KAYARAD HX-220, KAYARAD HX-620, KAYARAD R-551, KAYARAD R-712, KAYARAD R-604, KAYARAD R-684 (all manufactured by Nippon Kayaku Co., Ltd.), etc.

[0163] Examples of (meth)acrylate compounds with three or more functions include trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, isocyanurate tri(meth)acrylate, pentaerythritol (tri / tetra)(meth)acrylate, diglycerol (tetra)(meth)acrylate, bis(trimethylolpropane (tetra / penta / hexa)(meth)acrylate, triglycerol (penta)(meth)acrylate, dipentaerythritol (tetra / penta / hexa)(meth)acrylate, etc.

[0164] Furthermore, (meth)acrylate compounds with three or more functional groups can be obtained by forming (meth)acrylates from an alcohol having three or more oxyalkylene groups capable of intramolecular addition as a central backbone, and to which oxyalkylene groups such as oxyethylidene, oxypropylene, or oxybutylidene are added, with (meth)acrylate. Examples include trimethylolpropane epoxy-modified tri(meth)acrylate, glycerol epoxy-modified tri(meth)acrylate, epoxy-modified isocyanurate tri(meth)acrylate, epoxy-modified pentaerythritol (tri / tetra)(meth)acrylate, diglycerol epoxy-modified tetra(meth)acrylate, epoxy-modified bis(trimethylolpropane) (tetra / penta / hexa)(meth)acrylate, triglycerol epoxy-modified penta(meth)acrylate, and epoxy-modified dipentaerythritol (tetra / penta / hexa)(meth)acrylate.

[0165] As a compound having olefinic unsaturated bonds with more than three functions, from the point of view of tightness, it may contain epoxide-modified pentaerythritol (tris / tetra) (meth) acrylate and / or epoxide-modified dipentaerythritol (tris / tetra) (meth) acrylate.

[0166] Commercially available compounds containing olefinic unsaturated bonds with three or more functions include, for example, NK ESTER (registered trademark) A-TMPT, NK ESTER A-TMPT-9EO, NK ESTER AT-20E, NK ESTER A-GLY-3E, NK ESTER A-GLY-9E, NK ESTER A-GLY-20E, NK ESTER A-9300, NK ESTER A-9200YN, NK ESTER A-TMM-3, NK ESTER A-TMM-3L, NK ESTER A-TMM-3LM-N, NK ESTER A-TMMT, NK ESTER ATM-35E, NK ESTER AD-TMP, NK ESTER A-DPH, NK ESTER A-9550, NK ESTER A-DPH-12E, NK ESTER TPOA-50, NK oligo (registered trademark) UA-7100, and NK oligo. UA-1100H, NK oligo U-6LPA, NKoligo UA-33H, NK oligo U-10HA, NK oligo U-10PA, NK oligo U-15HA (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Light Acrylate (registered trademark) TMP-A, cPE-3A, Light Acrylate PE-4A, Light Acrylate DPE-6A (all manufactured by Kyoeisha Chemical Co., Ltd.), FA-731A (manufactured by Resonac), TMPTA, EBECRYL160S, OTA 480, PETIA, PETRA, EBECRYL 40, PETA, EBECRYL 140, EBECRYL 1140, EBECRYL1142, DPHA, EBECRYL 895, EBECRYL 896, EBECRYL TMPTMA (all manufactured by Daicel-Allnex), SR351S, SR368, SR415, SR444, SR454, SR492, SR499, CD501, SR502, SR9020, D9021, SR9035, SR295, SR355, SR399, SR494, SR9041 (all manufactured by Arkema), KAYARAD (registered trademark) GPO-303, KAYARAD TMPTA, KAYARAD THE-330, KAYARAD TPA-330, KAYARAD PET-30, KAYARAD T-1420(T), KAYARAD RP-1040, KAYARADDPHA, KAYARAD DPEA-12, KAYARAD D-310, KAYARAD DPCA-20 (all manufactured by Nippon Kayaku Co., Ltd.), etc.

[0167] The above-mentioned component (B) preferably includes the following components:

[0168] (b1) A compound having an olefinic unsaturated bond concentration of 0.0020 mol / g or higher and containing two olefinic unsaturated bonds per molecule. This allows for a balance between achieving a dense cross-linked structure formed through exposure and obtaining a photosensitive resin layer with moderate toughness. Therefore, even with a low weight-average molecular weight of component (A), the adhesion of the resist pattern is easily ensured. Furthermore, during the post-development washing process, it is easy to prevent component (A) from dissolving from the cured resist pattern.

[0169] In the compounds contained in component (b1) above, from the viewpoint of ensuring the adhesion of the resist pattern, the concentration of olefinic unsaturated bonds is more preferably 0.0022 mol / g or more, and even more preferably 0.0024 mol / g or more. Furthermore, from the viewpoint of ensuring the developability of the obtained photosensitive resin layer and the appropriate toughness of the obtained photosensitive resin layer, the concentration of olefinic unsaturated bonds in the compounds contained in component (b1) above is preferably 0.0045 mol / g or less, more preferably 0.0040 mol / g or less, and even more preferably 0.0036 mol / g or less.

[0170] From the viewpoint of excellent peelability, resolution and adhesion, the content of component (b1) relative to the total amount of component (B) is preferably 50% by mass or more, more preferably 75% by mass or more, further preferably 90% by mass or more, and particularly preferably 100% by mass.

[0171] (b1) The preferred component is a difunctional (meth)acrylate compound, more preferably a di(meth)acrylate having a bisphenol A structure and a polyalkylene glycol di(meth)acrylate.

[0172] In polyalkylene glycol di(meth)acrylate, compounds contained as component (b1) can be listed, for example...

[0173] Compounds that are polyethylene glycol di(meth)acrylates and in which the number of repeating units of ethylene glycol is 1 to 19;

[0174] Compounds comprising polypropylene glycol di(meth)acrylate and propylene glycol having 1 to 14 repeating units; and

[0175] Compounds that are polytetramethylene glycol di(meth)acrylates, wherein the number of repeating units of tetramethylene glycol is 1 to 11; etc.

[0176] Compounds contained in component (b1) of di(meth)acrylates having a bisphenol A structure, such as those represented by general formula (III) below, and / or compounds with hydrogen added to the aromatic ring of those represented by general formula (III), and

[0177] R 2 X is a methyl or hydrogen atom. 2 Compounds with O = oxyethylidene and m3 + m4 = 2~14; and

[0178] R 2 For methyl or hydrogen atoms, X 2 Compounds with O = oxypropylidene and m3 + m4 = 2~13; etc.

[0179]

[0180] From the viewpoint of improving the reactivity of the photosensitive resin composition upon exposure and making the formed cross-linked structure dense, component (b1) preferably includes a di(meth)acrylate compound having a bisphenol A structure.

[0181] More preferably, it includes R in general formula (III) 2 For methyl or hydrogen atoms, X 2 Compounds with O = oxyethylidene and m3 + m4 = 2~14

[0182] Further preferred formula (III) includes R 2 For methyl or hydrogen atoms, X 2 O = oxyethylidene, m3 + m4 = 2~10 compounds.

[0183] The content of the di(meth)acrylate compound having the bisphenol A structure in component (B) is more preferably 25% by mass or more, further preferably 50% by mass or more, even more preferably 75% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the total amount of component (B).

[0184] The content of the di(meth)acrylate compound having a bisphenol A structure in component (b1) is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 90% by mass or more, based on the total amount of component (b1). The above content can be 100% by mass based on the total amount of component (b1).

[0185] (B) The concentration of olefinic unsaturated bonds in the overall composition is preferably 0.0020 mol / g or more and 0.0050 mol / g or less. A concentration of 0.0020 mol / g or more appropriately increases the crosslinking density of the photosensitive resin layer during exposure, and during the post-development washing process, it easily prevents the photosensitive resin component from dissolving from the cured resist pattern, thereby easily preventing contamination of the washing process. A concentration of 0.0050 mol / g or less reduces the likelihood of defects in the cured resist pattern during the post-development washing process, thus reducing the likelihood of peeling.

[0186] (B) The concentration of olefinic unsaturated bonds in the overall composition is more preferably 0.0022 mol / g or more, and even more preferably 0.0024 mol / g or more. Furthermore, it is more preferably 0.0045 mol / g or less, and even more preferably 0.0040 mol / g or less.

[0187] In this embodiment, the mass ratio of the photosensitive resin composition {total content of component (A) / total content of component (B)} is preferably 1.00 or more and 1.80 or less.

[0188] By setting the above value to 1.00 or higher, a photosensitive resin composition with excellent adhesion can be easily obtained; by setting the above value to 1.80 or lower, a photosensitive resin composition with excellent developability and resolution can be easily obtained. That is, by setting the ratio of the total content of component (A) to the total content of component (B) within the above range, a photosensitive resin composition with an excellent balance of developability, adhesion, and resolution can be easily obtained. Of particular, from the viewpoint of easily obtaining a photosensitive resin composition with excellent adhesion, the ratio of the total content of component (A) to the total content of component (B) is more preferably 1.20 or higher. From the same viewpoint, the above value is further preferably 1.30 or higher, and particularly preferably 1.40 or higher.

[0189] When the ratio of the total content of component (A) to the total content of component (B) is 1.20 or higher, the mechanism by which adhesion is improved without compromising developability and resolution is presumably as follows. In this embodiment, component (A) comprises a copolymer of (A-1) having a low weight-average molecular weight and containing structural units derived from compounds having hydroxyl groups (especially hydroxyalkyl (meth)acrylate). Therefore, even if the content of the aromatic ring structural units in component (A) is high, excellent developability is easily achieved. Thus, even if the ratio of the total content of component (A) to the total content of component (B) is increased, developability is not easily compromised, and the adhesion effect brought about by the aromatic ring structural units in component (A) is easily maximized.

[0190] (C) Component: Photopolymerization initiator

[0191] (First (C) component)

[0192] The first component (C) is a photopolymerization initiator with a bimidazole structure, and is a compound used to initiate the free radical polymerization of component (B) by exposure.

[0193] The content of the first (C) component relative to the total solid content of the photosensitive resin composition can be 3.0% by mass or more, and from the viewpoint of excellent sensitivity and adhesion, it is preferably 4.0% by mass or more, more preferably 5.0% by mass or more. In addition, from the viewpoint of excellent solubility, it is preferably 10% by mass or less, more preferably 8.0% by mass or less, and even more preferably 6.0% by mass or less.

[0194] As the first (C) component, examples include dimers of compounds having the profen base structure (profen base dimers), namely dimers of 2,4,5-triarylimidazolium.

[0195] Examples of dimers of profenol, namely 2,4,5-triarylimidazole, include the dimer of 2-(o-chlorophenyl)-4,5-diphenylimidazole (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 2,2'-(o-chlorophenyl)-4 4',5,5'-Tetra-(3,4-dimethoxyphenyl)-Bimidazole, 2,2'-Bis-(2-fluorophenyl)-4,4',5,5'-Tetra-(3-methoxyphenyl)-Bimidazole, 2,2'-Bis-(2,3-difluoromethylphenyl)-4,4',5,5'-Tetra-(3-methoxyphenyl)-Bimidazole, 2,2'-Bis-(2,4-difluorophenyl)-4,4',5,5'-Tetra-(3-methoxyphenyl)-Bimidazole, 2,2'-Bis-(2,5-difluorophenyl)-4,4',5,5'-Tetra-(3-methoxyphenyl)-Bimidazole, 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-(2,4,5-trifluorophenyl)-4,4',5,5'-tetra- 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, etc.

[0196] From the viewpoint of excellent sensitivity, resolution and tightness, the first (C) component preferably contains a profen base dimer, wherein, more preferably, it contains a 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer.

[0197] (C) The ingredients are not limited to those described above, and further ingredients may be exemplified.

[0198] (Second (C) component)

[0199] Examples of second (C) components include: N-aryl-α-amino acid compounds, quinone compounds, aromatic ketone compounds, anthracene derivatives, naphthalene derivatives, oxazole derivatives, acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, benzoin ether compounds, dialkyl ketals, thioxanone compounds, dialkylaminobenzoate compounds, oxime esters, acridine compounds, pyrazoline derivatives, esters of N-aryl amino acids, coumarin derivatives, and halogen compounds.

[0200] Examples of aromatic ketone compounds include benzophenone compounds. Examples of benzophenone compounds include benzophenone, milchone [4,4'-bis(dimethylamino)benzophenone], and 4-methoxy-4'-dimethylaminobenzophenone. From the viewpoint of sensitization effect and binding affinity, 4,4'-bis(diethylamino)benzophenone is preferred as an aromatic ketone compound.

[0201] In this specification, the term "anthracene derivative" refers to both anthracene and compounds derived therefrom. Examples of anthracene derivatives include anthracene, 9,10-dialkoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, and 10-phenyl-9-anthraboronic acid. From the viewpoint of sensitization effect and binding affinity, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, and 10-phenyl-9-anthraboronic acid are preferred, and 9,10-diphenylanthracene and 10-phenyl-9-anthraboronic acid are particularly preferred.

[0202] From the viewpoint of adhesion and the rectangularity of the anti-corrosion pattern, 1-phenyl-3-(4-tert-butyl-styrene)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octyl-phenyl)-pyrazoline, and 1-phenyl-3-(4-methoxystyrene)-5-(4-methoxyphenyl)-pyrazoline are preferred as pyrazoline derivatives.

[0203] When the photosensitive resin composition contains the second (C) component, from the viewpoint of storage stability, it is preferable to contain at least one of benzophenone compounds, pyrazoline compounds, anthracene compounds, and coumarin compounds, and more preferably to contain at least any one of benzophenone compounds and pyrazoline compounds.

[0204] The content of the second component (C) relative to the total solid content of the photosensitive resin composition is preferably 0 to 0.5% by mass, more preferably 0 to 0.2% by mass, even more preferably 0 to 0.1% by mass, even more preferably 0 to 0.05% by mass, and particularly preferably 0 to 0.025% by mass. By adjusting the content of component (D) within the above range, it is easy to reduce the absorbance in areas other than the exposure wavelength, thereby easily improving storage stability.

[0205] The first (C) component and the second (C) component are preferably used in combination. The (C) component (the first (C) component and / or the second (C) component) is a compound that helps promote the photopolymerization reaction and can be treated as a reagent with photopolymerization initiation function or as a reagent with sensitization function.

[0206] (D) Component: Polymerization inhibitor

[0207] Examples of components (D) include phenothiazine, p-methoxyphenol, hydroquinone, 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.

[0208] From the viewpoint of preservation stability, component (D) preferably includes any one of phenothiazine, p-methoxyphenol, tert-butylcatechol, and 2,6-di-tert-butyl-p-cresol.

[0209] From the viewpoint of excellent resolution, the content of component (D) relative to the total solid content of the photosensitive resin composition is preferably 10 to 5000 ppm, more preferably 50 to 1000 ppm, and even more preferably 50 to 500 ppm.

[0210] Other ingredients

[0211] The photosensitive resin composition may contain other components (base dyes, antioxidants, stabilizers, plasticizers, etc.) as needed.

[0212] Examples of basic dyes include Basic Green 1 [CAS No. (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Industry), 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 Industry), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], and Basic Yellow 2 [2465-27-2]. Among these, Basic Green 1 is preferred from the viewpoint of improving tinting strength, hue stability, and exposure contrast.

[0213] The content of the base dye relative to the total solids content of the photosensitive resin composition is preferably 0.001 to 3% by mass, more preferably 0.01 to 2% by mass, and even more preferably 0.04 to 1% by mass. From the viewpoint of obtaining good colorability, the content of the base dye is preferably above the lower limit mentioned above, while from the viewpoint of maintaining the sensitivity of the photosensitive resin layer, it is preferably below the upper limit mentioned above.

[0214] Examples of antioxidants include triphenyl phosphite (e.g., manufactured by ADEKA, trade name: TPP), tris(2,4-di-tert-butylphenyl) phosphite (e.g., manufactured by ADEKA, trade name: 2112), tris(mononylphenyl) phosphite (e.g., manufactured by ADEKA, trade name: 1178), and bis(mononylphenyl)-dinonylphenyl phosphite (e.g., manufactured by ADEKA, trade name: 329K).

[0215] In these cases, the content of the antioxidant is preferably 0.001 to 0.8% by mass relative to the total solids content of the photosensitive resin composition, more preferably 0.01 to 0.3% by mass. From the viewpoint of effectively exhibiting the hue stability of the resist pattern and improving the sensitivity of the photosensitive resin layer, the content of the antioxidant is preferably at or above the aforementioned lower limit. On the other hand, from the viewpoint of suppressing the color development of the resist pattern, effectively exhibiting hue stability, and improving adhesion, it is preferably at or below the aforementioned upper limit.

[0216] From the viewpoint of improving the thermal stability of the photosensitive resin composition, stabilizers can be used. Examples of stabilizers include at least one of epoxy alkyl compounds having a glycidyl group and benzotriazole compounds. They can be used alone or in combination of two or more.

[0217] Examples of alkyl oxide 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.

[0218] Examples of benzotriazole compounds include carboxybenzotriazole, 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, 1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,3-benzotriazole, 1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,3-tolyltriazole, 1-(N,N-bis-2-hydroxyethyl)aminomethyl)-1,2,3-benzotriazole, and 1-(N,N-bis(2-ethylhexyl)aminomethyl)-5-carboxy-1,2,3-benzotriazole.

[0219] The total content of antioxidants, glycidyl alkyl oxide compounds and benzotriazole compounds in the photosensitive resin composition is preferably 0.001 to 3% by mass, more preferably 0.05 to 1% by mass, relative to the total solid content of the photosensitive resin composition.

[0220] In this embodiment, the photosensitive resin composition may contain a color-developing dye that develops color upon light irradiation. Examples of color-developing dyes include combinations of known leuco dyes and halogen compounds. Examples of leuco dyes include tris[(4-dimethylamino)phenyl]methane [leuco crystal violet] and bis[(4-dimethylamino)phenyl]phenylmethane [leuco malachite green]. Examples of halogen compounds include bromopentane, bromoisopentane, isobutylene bromide, ethylene bromide, diphenylbromomethane, dibromotoluene, 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, and hexachloroethane.

[0221] In this embodiment, additives such as plasticizers may be included in the photosensitive resin composition as needed. Examples of additives include phthalates such as diethyl phthalate, o-toluenesulfonamide, p-toluenesulfonamide, tributyl citrate, triethyl citrate, acetyl triethyl citrate, tri-n-propyl acetyl citrate, tri-n-butyl acetyl citrate, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ethers, and polypropylene glycol alkyl ethers.

[0222] <Protective Film>

[0223] The photosensitive resin laminate of this embodiment may include a protective film. A support film, a photosensitive resin layer, and a protective film may be laminated sequentially. The protective film may be laminated on the photosensitive resin layer side of the laminate of the support film and the photosensitive resin layer, and functions as a cover.

[0224] When the adhesion force between the photosensitive resin layer and the protective film is sufficiently less than the adhesion force between the photosensitive resin layer and the supporting film, the protective film can be easily peeled off from the photosensitive resin layer. For example, polyethylene film, polypropylene film, stretched polypropylene film, polyester film, etc., can be preferably used as the protective film.

[0225] Alternatively, a release layer can be applied to the surface of the protective film.

[0226] The thickness of the protective film is preferably 10~100μm, more preferably 10~50μm. Examples of protective films include ALPHAN (registered trademark) EM-501, ALPHAN E-200, ALPHAN E-201F, ALPHAN FG-201, ALPHAN MA-411 (all manufactured by Oji F-Tex), Torayfan (registered trademark) KW37, Torayfan 2578, Torayfan 2548, Torayfan 2500, Torayfan YM17S, Cerapeel (registered trademark) PJ271, Cerapeel PJ111, Cerapeel HP2, Cerapeel PJ101, Cerapeel WZ, Cerapeel MDA, Cerapeel MFA, Cerapeel TK07, Cerapeel BKE, Cerapeel BX8A, Cerapeel SY (all manufactured by Toray Industries), GF-18, GF-818, GF-858 (all manufactured by Tamapoly), etc.

[0227] [Photosensitive resin laminate roll]

[0228] The photosensitive resin laminate can be in the form of a strip, or it can be a strip of photosensitive resin laminate wound onto a core to form a roll.

[0229] [Methods for forming anti-corrosion patterns]

[0230] The method for forming the resist pattern of the photosensitive resin laminate using this embodiment preferably includes the following steps in sequence:

[0231] The process of laminating a photosensitive resin laminate onto a substrate;

[0232] The process of exposing the photosensitive resin layer of a laminated photosensitive resin stack; and

[0233] The process of developing the exposed photosensitive resin layer.

[0234] (Layering process)

[0235] In the lamination process, specifically when the photosensitive resin laminate includes a protective film, after the protective film is peeled off from the photosensitive resin laminate, the photosensitive resin layer is heated and pressed onto the surface of a support (e.g., a substrate) using a laminator, performing one or more laminations. Examples of substrate materials include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). The heating temperature during lamination is typically 40–160°C. Heating and pressing can be performed using a laminator equipped with rollers, or by repeatedly passing the substrate and photosensitive resin layer laminate through rollers. Heating and pressing can be performed under reduced pressure as needed.

[0236] (Exposure process)

[0237] In the exposure process, an exposure machine is used to expose the photosensitive resin layer. Exposure can be performed after the support has been peeled off, as needed. When exposure is performed through a photomask, the exposure amount is determined by the illuminance of the light source and the exposure time, and can be measured using a photometer. Direct imaging exposure can also be performed in the exposure process. In direct imaging exposure, exposure is performed on the substrate without using a photomask, using a direct drawing device. As the light source, a semiconductor laser with a wavelength of 350~410nm or an ultra-high pressure mercury lamp is used. When the pattern drawing is computer-controlled, the exposure amount is determined by the illuminance of the exposure light source and the moving speed of the substrate.

[0238] The light irradiation method used in the exposure process is preferably selected from at least one of the following methods: projection exposure, proximity exposure, contact exposure, direct imaging exposure, and electron beam direct imaging, and more preferably by projection exposure or direct imaging exposure.

[0239] A heating step can also be incorporated between the exposure and development steps. The heating temperature is preferably about 30 to about 200°C, more preferably 30 to 150°C, and even more preferably 35 to 120°C. Implementing this heating step improves resolution and adhesion. Heating can be achieved using hot air, infrared, or far-infrared heating furnaces, constant temperature baths, hot plates, hot air dryers, infrared dryers, hot rollers, etc.

[0240] More precisely, the elapsed time from the exposure step to the heating step, from the moment the exposure stops to the moment the heating starts, is preferably 10 to 600 seconds, more preferably 20 to 300 seconds. The elapsed time from the moment the heating starts to the moment the heating stops is preferably 1 to 120 seconds, more preferably 5 to 60 seconds.

[0241] (Developing process)

[0242] In the developing process, a developing apparatus is used to remove unexposed or exposed areas from the exposed photosensitive resin layer using a developing solution. If a support film is present on the photosensitive resin layer after exposure, it is removed. Next, a developing solution containing an alkaline aqueous solution is used to develop and remove the unexposed or exposed areas, resulting in a resist image.

[0243] The preferred alkaline solution is an aqueous solution of Na₂CO₃, K₂CO₃, tetramethylammonium hydroxide, etc. The alkaline solution is selected based on the characteristics of the photosensitive resin layer; typically, a Na₂CO₃ aqueous solution with a concentration of 0.2% to 2% by mass is used. Surfactants, defoamers, and small amounts of organic solvents to promote development can be added to the alkaline solution. The temperature of the developing solution during the developing process is preferably kept constant within the range of 20 to 40°C.

[0244] In the developing process, a water washing step is preferred for removing the developer contained in the resist pattern after developing. As the washing water, in addition to pure water and industrial water, it can be selected according to the characteristics of the photosensitive resin layer. To improve resolution and the shape of the resist pattern, a polyvalent metal salt such as MgSO4 at a concentration of 0.001 to 1% by mass can be added. The temperature of the washing water in the water washing step is preferably kept constant within the range of 20 to 40°C.

[0245] The above process yields an anti-corrosion pattern, but if needed, a further heating process at 60-300°C can be performed. This heating process improves the chemical resistance of the anti-corrosion pattern. The heating process can utilize a furnace employing hot air, infrared radiation, or far-infrared radiation.

[0246] In order to obtain a conductor pattern, a conductor pattern forming process can be performed after the developing or heating process, which involves etching or plating the substrate with the resist pattern.

[0247] The conductor pattern can be manufactured by, for example, using a metal plate or a metal-coated insulating plate as a substrate. After forming a resist pattern using the resist pattern forming method described above, a conductor pattern forming process is performed. In the conductor pattern forming process, a conductor pattern is formed on the substrate surface (e.g., the copper surface) exposed by development using a known etching or plating method.

[0248] Furthermore, after manufacturing the conductor pattern using the above-described conductor pattern manufacturing method, a stripping process is performed using an aqueous solution with a stronger alkalinity than the developer to peel the resist pattern off the substrate, thereby obtaining a wiring board (e.g., a printed wiring board) with the desired wiring pattern.

[0249] There are no particular restrictions on the alkaline aqueous solution (hereinafter also referred to as "stripping solution") used for stripping. A 2-5% by mass aqueous solution of NaOH or KOH, or an organic amine-based stripping solution, is typically used. A small amount of water-soluble solvent may be added to the stripping solution. Examples of water-soluble solvents include alcohols. The temperature of the stripping solution in the stripping process is preferably in the range of 40-70°C.

[0250] In this embodiment, the photosensitive resin laminate can be used in the manufacture of printed wiring boards; the manufacture of lead frames for IC chip mounting; precision machining of metal foils such as metal mask manufacturing; the manufacture of packages such as ball grid arrays (BGA) and chip-scale packages (CSP); the manufacture of strip substrates such as chip-on-film (COF) and tape-and-bundle automated bonding (TAB); the manufacture of semiconductor bumps; and the manufacture of spacers for flat panel displays such as ITO electrodes, addressing electrodes, and electromagnetic wave shielding.

[0251] It should be noted that, unless otherwise specified, the values ​​of the above parameters shall be determined according to the measurement methods in the embodiments described later.

[0252] Example

[0253] Hereinafter, examples and comparative examples will be provided to describe this embodiment. However, this embodiment is not limited to the following examples. Various manufacturing, measurement, and evaluation methods were performed in the examples and comparative examples.

[0254] [Example 1]

[0255] <(A) Synthesis of Components>

[0256] As shown in the table below, a solution (a) was prepared by mixing a specified monomer (copolymer component) with azobisisobutyronitrile at a specified mixing ratio (unit: parts by mass). In a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel, and nitrogen inlet tube, 200 parts by mass of methyl ethyl ketone and 100 parts by mass of ethanol were added. Nitrogen gas was then blown into the flask while stirring, and the temperature was raised to 80°C. Next, 100 parts by mass of the above solution (a) were added dropwise over 4 hours at a constant dropping rate, followed by stirring at 80°C for 2 hours.

[0257] Next, 0.5 parts by mass of azobisisobutyronitrile (AIB) were dissolved in 50 parts by mass of a mixture of 30 parts by mass of methyl ethyl ketone (MEK) and 20 parts by mass of ethanol (EQU) to prepare solution (b). In a flask, solution (b) was added dropwise at a constant rate over 10 minutes, and then stirred at 80°C for 3 hours. Subsequently, the mixture in the flask was heated to 90°C over 30 minutes, and then kept at 90°C with stirring for 2 hours. Stirring was then stopped, and the mixture was cooled to room temperature (25°C). This yielded solutions of alkali-soluble polymers A1 to A9. The weight-average molecular weights (Mw) of alkali-soluble polymers A1 to A9 are shown in the table.

[0258] The weight-average molecular weight was determined by gel permeation chromatography (GPC) and then derived using a standard curve of standard polystyrene. The GPC conditions are as follows.

[0259] (GPC conditions)

[0260] Pump: PU-4580 manufactured by Japan Seiko.

[0261] Degassing device: DG-2080-53

[0262] Column oven: CO-1560

[0263] The following are a total of 4 Shodex-manufactured steel columns: KF-807×1, KF-806M×2, and KF-802.5×1.

[0264] Eluent: Tetrahydrofuran

[0265] Measurement temperature: 40℃

[0266] Flow rate: 1.00 mL / min

[0267] Detector: RI-1530, manufactured by Japan Spectrophotometer

[0268] <Fabrication of Photosensitive Resin Layers and Photosensitive Resin Laminates>

[0269] The components shown in the table below are mixed in the amounts shown in the table below {the numbers for each component are the amounts mixed as solid components (unit: parts by mass)}, and then methyl ethyl ketone is added in such a way that the solid component concentration is 60%. The mixture is stirred thoroughly to obtain the formulation of the photosensitive resin composition. It should be noted that the amounts (parts by mass) shown in the table below are the mass of the non-volatile components (solid component amount).

[0270] As a support film, a 16 μm thick polyethylene terephthalate film (manufactured by Toray Industries, QS71) was prepared. The above-mentioned prepared solution was uniformly coated onto the surface of the support film using a bar coater, and then dried in a dryer at 95°C for a specified time. This yielded a photosensitive resin laminate with a photosensitive resin layer of a specified thickness on the support film.

[0271] The photosensitive layer of the photosensitive resin laminates in Examples 1-24 and Comparative Examples 1-3 had a film thickness of 25 μm and a drying time of 2 minutes and 30 seconds. The photosensitive layer of the photosensitive resin laminate in Example 25 had a film thickness of 15 μm and a drying time of 1 minute and 30 seconds. The photosensitive layer of the photosensitive resin laminate in Example 26 had a film thickness of 7 μm and a drying time of 45 seconds.

[0272] Next, a 19 μm thick polyethylene film (manufactured by TAMAPOLY CO., LTD., GF-818) serving as a protective film is laminated onto the surface of the photosensitive resin layer opposite to the support film. Here, the laminate of the support film, the photosensitive resin layer, and the protective film is treated as a photosensitive resin laminate (Example).

[0273] It should be noted that, by using the photosensitive resin laminate of the above embodiments, either the method for forming resist patterns or the method for forming wiring boards can be suitably realized by conventional methods.

[0274] [Measurement and evaluation, etc.]

[0275] <Substrate leveling>

[0276] The surface of a copper-clad laminate with a total thickness of 0.4 mm and 18 μm of rolled copper foil was cleaned with a 10% (w / w) H₂SO₄ aqueous solution, followed by rinsing with pure water. The cleaned copper-clad laminate was preheated to 50°C.

[0277] <Lamination Process>

[0278] While peeling a protective film from the photosensitive resin laminate by contacting the surface of the copper-clad laminate preheated to 50°C, lamination is performed using a hot roll laminator (Asahi Kasei Corporation, AL-700) at a roll temperature of 105°C. This yields an evaluation substrate. The lamination pressure is set to 0.35 MPa, and the lamination speed is set to 1.5 m / min.

[0279] <Exposure Process>

[0280] For the evaluation substrate that has been laminated for 2 hours, exposure is performed using a projection exposure machine (USHIO INC., UX-2003SM-AGG01) at a wavelength of 365nm using a specified projection exposure mask pattern.

[0281] <Heating Process>

[0282] Using a constant-temperature thermostat (manufactured by Yamato Scientific Co., Ltd., DKM600) set to 60°C, the evaluation substrate, which had been exposed for 1 minute, was heated for 30 seconds.

[0283] <Developing Process>

[0284] The support film is peeled off from the photosensitive resin layer. Then, using an alkaline developer (manufactured by FUJI KIKO CO., LTD., a dry film developer), development is performed at 30°C using a 1% (w / w) Na₂CO₃ aqueous solution under a spray pressure of 0.15 Pa for a specified time. Then, the photosensitive resin layer is washed by spraying pure water onto it for a specified time. This forms a resist pattern on the evaluation substrate.

[0285] <Optimal Exposure>

[0286] Using a mask pattern with a linewidth (L) / line spacing width (S) (hereinafter referred to as "L / S") of 8 / 8 (unit: μm) (refer to...) Figure 1 A photomask is used to expose the evaluation substrate after the above lamination process (exposure process). Then, a heating process and a development process are performed, thereby forming a resist pattern on the evaluation substrate. The formed resist pattern is observed using an optical microscope at 100x magnification to observe the linewidth of the pattern. An exposure dose of 8 μm linewidth (unit: mJ / cm²) is used. 2 The optimal exposure is used as the basis for all the exposure values ​​used in the following evaluations.

[0287] Figure 1 This is a top view showing a structural example of a mask pattern.

[0288] In the figure, within region 100 of the photomask, the area through which exposure light is transmitted is indicated by reference numeral 10 (transmitting region 10), while the area through which exposure light is not transmitted is indicated by reference numeral 1 (shading region 1). In the figure, the shading region 1 is indicated by a diagonal line.

[0289] The transmissive region 10 has a predetermined width and extends in the x-direction, and a plurality of these transmissive regions 10 are arranged at predetermined intervals in the width direction (y-direction). In this embodiment, the unexposed portion of the photosensitive resin layer is removed after the above-described development process; therefore, based on... Figure 1 The mask pattern can theoretically be designed to form an etch-resistant pattern with an L / S ratio corresponding to the width (L: line) of the transmission region 10 and the width (S: line spacing) of the shading region 1.

[0290] <Shortest development time>

[0291] The evaluation substrate after the above lamination process is subjected to the above development process to determine the minimum time required for the photosensitive resin layer to completely dissolve, and then this time is used as the shortest development time.

[0292] <Reproducibility>

[0293] The developability is evaluated based on the following criteria. The shorter the development time, the better the developability. In this embodiment, a development time of 23 seconds or less, i.e., an evaluation grade of C or higher, is considered acceptable.

[0294] (Benchmark)

[0295] A: The shortest development time is less than 17 seconds.

[0296] B: The shortest development time is more than 17 seconds but less than 20 seconds.

[0297] C: The shortest development time is more than 20 seconds but less than 23 seconds.

[0298] D: The shortest development time exceeds 23 seconds.

[0299] <Seamlessness>

[0300] Use a mask pattern with L / S of x / 3x{x=1~10 (varying in 0.5μm intervals)} (unit: μm) (refer to) Figure 2 The evaluation is performed using a photomask. Specifically, the evaluation substrate obtained after the above-described leveling and lamination processes is exposed to the photomask with optimal exposure. Then, a resist pattern is formed through the above-described heating and development processes.

[0301] Figure 2 This is a top view showing a structural example of a mask pattern.

[0302] In the figure, within region 100A of the photomask, the transmission region 10 and the light-blocking region 1 are shown. Figure 2 In region 100A shown, the value of L / S is... Figure 1 The area shown is different from 100.

[0303] The formed resist pattern was observed using an optical microscope at 100x magnification. In the observed image, lines (exposed areas) without serpentine patterns or defects were inspected, and their adhesion was evaluated based on their minimum linewidth, according to the following criteria. A smaller minimum linewidth was considered better adhesion. In this embodiment, a minimum linewidth of 7.5 μm or less, i.e., an evaluation grade of C or higher, was considered acceptable.

[0304] (Benchmark)

[0305] A: The minimum line width is below 5.5μm.

[0306] B: Minimum linewidth exceeds 5.5μm but is below 6.5μm.

[0307] C: Minimum linewidth exceeding 6.5μm but below 7.5μm.

[0308] D: Minimum linewidth exceeds 7.5μm.

[0309] <resolution>

[0310] Use a mask pattern with an L / S of 3x / x{x=1~10 (varying in 0.5μm intervals)} (unit: μm) (refer to) Figure 3 The evaluation is performed using a photomask. That is, the evaluation substrate obtained through the above-described leveling and lamination processes is exposed to the photomask with optimal exposure. Then, a resist pattern is formed through the above-described heating and development processes.

[0311] Figure 3 This is a top view showing a structural example of a mask pattern.

[0312] In the figure, within region 100B of the photomask, a transmission region 10 and a light-shielding region 1 are shown. The light-shielding region 1 has a defined width and extends in the x-direction, and multiple light-shielding regions 1 are arranged at defined intervals in the width direction (y-direction). This is achieved by... Figure 3 The mask pattern, and based on Figure 1 Similarly, in the case of mask patterns, it is theoretically envisioned to form an etch-resistant pattern with an L / S ratio corresponding to the width (L: line) of the transmission region 10 and the width (S: line spacing) of the shading region 1.

[0313] The formed resist pattern was observed using an optical microscope at 100x magnification. In the observed image, lines (exposed areas) without serpentine patterns or defects were inspected. Resolution was evaluated based on the width between these lines (line spacing), according to the following criteria: the smaller the line spacing, the better the resolution. In this embodiment, line spacing of 7.5 μm or less, i.e., an evaluation grade of C or higher, was considered acceptable.

[0314] (Benchmark)

[0315] A: Line spacing width is less than 5.5um.

[0316] B: Line spacing width exceeds 5.5um but is less than 6.5um.

[0317] C: Line spacing width exceeds 6.5um but is less than 7.5um.

[0318] D: Line spacing exceeds 7.5um.

[0319] <Flexibility>

[0320] A flexible substrate {NIKKAN INDUSTRIES CO., LTD. NIKKAFLEX F-30VC1 25RC11(H)} was prepared and cut to a size of 200mm × 250mm. Then, a photosensitive resin layer was formed on this substrate through the aforementioned lamination process. Next, it was exposed to the substrate with the optimal exposure, a width of 1 inch, and a length of 250mm. Then, it was developed and washed according to the aforementioned development process, following the heating process described above and for twice the minimum development time. Finally, a 1.2-inch wide sample was cut from the substrate with the 1-inch wide cured photosensitive resin layer centered in the width direction.

[0321] Mandrel tests were performed using the fabricated samples (cylindrical mandrel method; bending resistance test according to JIS K5600-5-1-1999). Then, the diameter of the smallest mandrel in the photosensitive resin layer on the sample where no "cracks" and / or "peeling from the substrate" were detected (minimum mandrel diameter) was determined. Based on this diameter, flexibility was evaluated according to the following criteria. A smaller value indicates higher flexibility.

[0322] (Softness)

[0323] A: The minimum mandrel diameter is 8mm or less.

[0324] B: The minimum mandrel diameter is more than 8mm but less than 10mm.

[0325] C: The minimum mandrel diameter is more than 10mm but less than 13mm.

[0326] D: The minimum mandrel diameter exceeds 13mm.

[0327] In the table below,

[0328] "The proportion of aromatic rings in component (A)" is equivalent to "the content of structural units in component (A) derived from compounds having aromatic rings".

[0329] "The mass ratio of component (A) to component (B)" is equivalent to "the mass ratio in the photosensitive resin composition {total content of component (A) / total content of component (B)}".

[0330] "The content of component (b1)" is equivalent to "the content of component (b1) based on the total amount of component (B)".

[0331] "The content of compounds that are (b1) components and have a Bis-A structure" is equivalent to "the content of compounds that are (b1) components and have a bisphenol A structure, based on the total amount of (B) components".

[0332] (B) The average number of repeating units (ethylene oxide and / or propylene oxide) in the component is equivalent to the number of repeating units in one molecule obtained by numerical averaging.

[0333] In addition, the “concentration of olefinic unsaturated bonds” in the claims is equivalent to the “concentration of double bonds (mol / g)” in each component in the table below, that is, the concentration of double bonds (mol / g) calculated based on the number average number of repeating units in each (B) component.

[0334] [Table 1]

[0335]

[0336] [Table 2]

[0337]

[0338] [Table 3]

[0339]

[0340] [Table 4]

[0341]

[0342] As can be confirmed from the table, in the embodiments, good results were observed in any of the evaluations of <adhesion>, <resolution>, and <developability>.

[0343] Industrial availability

[0344] According to the present invention, a photosensitive resin laminate with good adhesion, resolution, and developability can be obtained. This photosensitive resin laminate can be widely used for forming resist patterns in printed wiring boards and the like.

[0345] Explanation of reference numerals in the attached figures

[0346] 1: Shaded area

[0347] 10: Transmission area

[0348] 100, 100A, 100B: Regions within the photomask

[0349] L: Line

[0350] S: Line spacing

Claims

1. A photosensitive resin laminate comprising: a support film and a photosensitive resin layer comprising a photosensitive resin composition, The photosensitive resin composition comprises the following components: (A) Alkali-soluble polymers, (B) Compounds containing olefinic unsaturated bonds (C) Photopolymerization initiator, The (A) component comprises the following components: (A-1) is a copolymer containing structural units derived from (meth)acrylate hydroxyalkyl esters and having a weight-average molecular weight of less than 25,000. The content of structural units derived from compounds having aromatic rings in component (A) is 50% by mass or more, based on the total mass of all monomeric components.

2. The photosensitive resin laminate according to claim 1, wherein, The proportion of the (A-1) copolymer in component (A) is 50% by mass or more.

3. The photosensitive resin laminate according to claim 1, wherein, Component (B) comprises the following components: (b1) A compound having an olefinic unsaturated bond concentration of 0.0020 mol / g or higher and having two olefinic unsaturated bonds per molecule.

4. The photosensitive resin laminate according to claim 3, wherein, In component (b1), the concentration of the olefinic unsaturated bond is 0.0024 mol / g or higher.

5. The photosensitive resin laminate according to claim 3, wherein, In component (b1), the concentration of the olefinic unsaturated bond is 0.0040 mol / g or higher.

6. The photosensitive resin laminate according to claim 3, wherein, The component (b1) is a di(meth)acrylate having a bisphenol A structure.

7. The photosensitive resin laminate according to claim 3, wherein, The content of component (b1) is 75% by mass or more, based on the total amount of component (B).

8. The photosensitive resin laminate according to claim 3, wherein, The content of component (b1) is 90% by mass or more, based on the total amount of component (B).

9. The photosensitive resin laminate according to claim 3, wherein, Component (B) comprises a compound represented by the following general formula (III) as component (b1): In the formula, R 2 X is a methyl or hydrogen atom. 2 O represents oxyethylidene, and m3+m4 are integers from 2 to 10.

10. The photosensitive resin laminate according to claim 1 or 2, wherein, The weight-average molecular weight of the (A-1) copolymer is 10.000~21000.

11. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of the aromatic ring structural unit in component (A) is 60% by mass or more.

12. The photosensitive resin laminate according to claim 1 or 2, wherein, The content of the aromatic ring structural unit in component (A) is 65% by mass or more.

13. The photosensitive resin laminate according to claim 1 or 2, wherein, The mass ratio of the photosensitive resin composition, i.e., the total content of component (A) / the total content of component (B), is 1.30 or more.

14. The photosensitive resin laminate according to claim 1 or 2, wherein, The mass ratio of the photosensitive resin composition, i.e., the total content of component (A) / the total content of component (B), is 1.40 or more.

15. The photosensitive resin laminate according to claim 1 or 2, wherein, The mass ratio of the photosensitive resin composition, i.e., the total content of component (A) / the total content of component (B), is 1.80 or more.

16. The photosensitive resin laminate according to claim 1 or 2, wherein, A protective film is provided on the side of the photosensitive resin layer opposite to the support.

17. The photosensitive resin laminate according to claim 1 or 2, wherein, The thickness of the photosensitive resin layer is 1~20μm.

18. The photosensitive resin laminate according to claim 1 or 2, wherein, The thickness of the photosensitive resin layer is 3~15μm.

19. The photosensitive resin laminate according to claim 1 or 2, wherein, The thickness of the photosensitive resin layer is 5~10μm.

20. A method for forming a resist pattern, comprising: The process of laminating the photosensitive resin laminate according to any one of claims 1 to 9 onto a substrate; The process of exposing the photosensitive resin layer of the laminated photosensitive resin laminate; and The process of developing the exposed photosensitive resin layer.

21. A method for forming a wiring board, comprising: The process of forming a resist pattern on a substrate using the photosensitive resin laminate according to any one of claims 1 to 9; A process of forming conductor patterns by etching or plating a substrate with resist patterns; and The process of peeling the resist pattern from the substrate.

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