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

Abstract

The present invention provides a photosensitive resin laminate excellent in developability of a photosensitive resin layer, adhesion of a resist pattern to be obtained, and resolution.　This photosensitive resin laminate comprises a support film and a photosensitive resin layer containing a photosensitive resin composition, wherein the photosensitive resin composition contains the following components. (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a photopolymerization initiator, wherein component (A) contains the following components.　(A-1) a copolymer containing a constituent unit derived from a hydroxyalkyl (meth)acrylate and having a weight average molecular weight of 25,000 or less, and the content of a constituent unit derived from a compound having an aromatic ring in the component (A) is 50 mass% or more on the basis of the total mass of all monomer components.

Description

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

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

[0002] In electronic devices such as printed wiring boards, wiring patterns are generally manufactured using a photolithography process. In recent years, with the trend toward smaller and denser electronic devices, photolithography processes are being required to form finer wiring than ever before. For example, modified semi-additive processes (MSAP) and semi-additive processes (SAP) are often used as methods for manufacturing wiring boards.

[0003] Patent Document 1 proposes a photosensitive resin composition containing a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and an anthracene-based sensitizer, the binder polymer having hydroxyalkyl(meth)acrylate units and styrene or styrene derivative units, and the content of the styrene or styrene derivative units is 40 mass% or more. Patent Document 1 reports that the use of such a photosensitive resin composition makes it possible to form a resist pattern with excellent adhesion and resolution.

[0004] International Publication No. 2021 / 193232

[0005] In the photolithography process, in addition to the adhesion and resolution of the resist pattern, excellent developability of the photosensitive resin layer is also required. However, Patent Document 1 leaves room for improvement in terms of achieving a balance between the developability of the photosensitive resin layer and the adhesion and resolution of the resulting resist pattern, and satisfying these requirements.

[0006] Therefore, an object of the present invention is to provide a photosensitive resin laminate that exhibits excellent developability of a photosensitive resin layer and excellent adhesion and resolution of the resulting resist pattern, and a method for forming a resist pattern and a method for forming a wiring board using such a photosensitive resin laminate.

[0007] One aspect of the present invention is as follows. [Document Title] Claims [1] A photosensitive resin laminate comprising a support film and a photosensitive resin layer containing a photosensitive resin composition, wherein the photosensitive resin composition contains the following components: (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a photopolymerization initiator, and the component (A) contains the following components: (A-1) a copolymer containing a structural unit derived from a hydroxyalkyl (meth)acrylate and having a weight-average molecular weight of 25,000 or less, and the content of the structural unit derived from a compound having an aromatic ring in the component (A) is 50 mass% or more based on the total mass of all monomer components. [2] The photosensitive resin laminate according to item 1, wherein the proportion of the (A-1) copolymer in the component (A) is 50 mass% or more. [3] The photosensitive resin laminate according to item 1 or 2, wherein the component (B) comprises the following component: (b1) a compound having an ethylenically unsaturated bond concentration of 0.0020 mol / g or more and having two ethylenically unsaturated bonds per molecule. [4] The photosensitive resin laminate according to item 3, wherein the component (b1) has an ethylenically unsaturated bond concentration of 0.0024 mol / g or more. [5] The photosensitive resin laminate according to item 3, wherein the component (b1) has an ethylenically unsaturated bond concentration of 0.0040 mol / g or more. [6] The photosensitive resin laminate according to item 3, wherein the component (b1) is a di(meth)acrylate having a bisphenol A structure. [7] The photosensitive resin laminate according to item 3 or 4, wherein the content of the component (b1) is 75 mass% or more based on the total amount of the component (B). [8] The photosensitive resin laminate according to any one of items 3 to 7, wherein the content of the component (b1) is 90 mass% or more based on the total amount of the component (B). [9] The component (B) contains, as the component (b1), a compound represented by the following general formula (III): (In the formula, R ２ is a methyl group or a hydrogen atom, and X ２wherein O is an oxyethylene group, and m3 + m4 is an integer of 2 to 10.

[10] The photosensitive resin laminate according to any one of items 1 to 9, wherein the weight-average molecular weight of the copolymer (A-1) is 10,000 to 21,000.

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

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

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

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

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

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

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

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

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

[20] A method for forming a resist pattern, comprising: a step of laminating the photosensitive resin laminate according to any one of items 1 to 19 onto a substrate; a step of exposing the photosensitive resin layer of the laminated photosensitive resin laminate; and a step of developing the photosensitive resin layer after exposure.

[21] A method for forming a wiring board, comprising: a step of forming a resist pattern on a substrate using the photosensitive resin laminate according to any one of items 1 to 19; a step of forming a conductor pattern by etching or plating the substrate on which the resist pattern has been formed; and a step of peeling the resist pattern from the substrate.

[0008] According to the present invention, it is possible to provide 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, and also to provide a method for forming a resist pattern and a method for forming a wiring board using such a photosensitive resin laminate.

[0009] 1A and 1B are plan views showing the configuration of a mask pattern related to this embodiment, 2A and 2B are plan views showing the configuration of a mask pattern related to this embodiment, and 3A and 3B are plan views showing the configuration of a mask pattern related to this embodiment.

[0010] The present invention is not limited to the present embodiment, but can be practiced in various modifications within the scope of the present invention.

[0011] In the present specification, when a plurality of structures represented by the same symbol exist in the same formula, the structures may be independently selected and may be the same or different from each other, unless otherwise specified. When a plurality of structures represented by the same symbol exist in different formulas, the structures may be independently selected and may be the same or different from each other, unless otherwise specified. In the present specification, various measurements are carried out based on the methods described in the Examples unless otherwise specified. In the present specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced by the upper or lower limit of a corresponding numerical range described in another stepwise manner, and may further be replaced by the corresponding value described in the Examples.

[0012] In this specification, "(meth)acrylic" means "acrylic" and / or "methacrylic", "(meth)acrylate" means "acrylate" and / or "methacrylate", and "(meth)acryloyl" means "acryloyl" and / or "methacryloyl". A "compound containing a (meth)acryloyl group" is referred to as, for example, a "(meth)acrylate compound". In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the function of the process is achieved. In the drawings, the scale, shape, and length may be exaggerated for clarity. In this specification, the "solid content" of a photosensitive resin composition means components of the photosensitive resin composition other than the solvent.

[0013] In one embodiment, unless otherwise specified, "adhesion" refers to the adhesion performance between the resist pattern and the substrate; "resolution" refers to the resolution performance of the resist pattern; and "developability" refers to the developability of the unexposed areas of the photosensitive resin layer (resist).

[0014] [Photosensitive Resin Laminate] The photosensitive resin laminate of the present embodiment is a photosensitive resin laminate including a support film and a photosensitive resin layer containing a photosensitive resin composition, wherein the photosensitive resin composition contains the following components: (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a photopolymerization initiator, and the component (A) contains the following component: (A-1) a copolymer containing a structural unit derived from a hydroxyalkyl (meth)acrylate and having a weight-average molecular weight of 25,000 or less, and the content of the structural unit derived from a compound having an aromatic ring in the component (A) is 50 mass% or more based on the total mass of all monomer components.

[0015] A high content of structural units derived from a compound having an aromatic ring in component (A) makes it easier to ensure, for example, good adhesion. However, in this case, to ensure similarly good properties other than adhesion (e.g., developability, etc.), the composition of the photosensitive resin composition must be further investigated. In this regard, although incorporating structural units derived from a compound having a hydroxyl group (particularly a hydroxyalkyl (meth)acrylate) into component (A) is considered to be advantageous, for example, in terms of resolution, it has been difficult with conventional techniques to balance various properties and satisfy these requirements. Here, this embodiment controls the content of structural units derived from a compound having an aromatic ring in component (A) to 50% by mass or more, and the component (A) includes the following component: (A-1) a copolymer containing structural units derived from a compound having a hydroxyl group (particularly a hydroxyalkyl (meth)acrylate) and having a weight-average molecular weight of 25,000 or less. In this embodiment, such a low molecular weight copolymer (A-1) is intentionally used from the viewpoint of balancing and satisfying various properties. Furthermore, in this embodiment using such a copolymer (A-1), various properties can be more easily ensured by targeting and controlling specific aspects, including the configuration of component (B) and / or the amount of component (B). In this specification, the compound having a hydroxyl group in copolymer (A-1) is a hydroxyalkyl (meth)acrylate.

[0016] For example, in order to further improve the adhesion and resolution of the photosensitive resin layer, measures can be taken to facilitate the improvement of crosslink density during exposure, such as increasing the concentration of ethylenically unsaturated bonds in component (B).In this regard, for the flexibility (flexibility) of the obtained photosensitive resin layer after exposure, it is often advantageous to use an alkali-soluble polymer with a large weight-average molecular weight as the alkali-soluble polymer.That is, when attempting to balance adhesion, resolution, and developability by containing a large amount of low-molecular-weight alkali-soluble polymer, and further attempting to improve adhesion and resolution by increasing the concentration of ethylenically unsaturated bonds in component (B), the flexibility (flexibility) of the photosensitive resin layer after exposure tends to deteriorate. On the other hand, in a preferred aspect of the present embodiment, a photosensitive resin composition is designed using a relatively large amount of a predetermined (B) component (a bifunctional monomer among the (B) components that, as will be described later, facilitates an improvement in crosslink density upon exposure), thereby improving the crosslink density after exposure and enabling a flexible cured film to be obtained by linearly crosslinking the (B) components together, and thus making it easy to ensure flexibility despite the use of an alkali-soluble polymer with a low molecular weight.

[0017] This embodiment includes at least a support film and a photosensitive resin layer containing a photosensitive resin composition. The photosensitive resin laminate may include other layers in addition to the support film and the photosensitive resin layer. Examples of the other layers include an intermediate layer provided between the support film and the photosensitive resin layer, a protective film provided on the side of the photosensitive resin layer opposite the support film, and a release layer provided between the protective film and the photosensitive resin layer.

[0018] The photosensitive resin laminate is configured, for example, by laminating a photosensitive resin layer directly on a support film, or by laminating a photosensitive resin layer on the support film via an intermediate layer. The photosensitive resin layer may be one layer or two or more layers. From the viewpoint of easily achieving the effects of this embodiment, the photosensitive resin laminate is preferably a dry film resist or a transfer film, and more preferably a dry film resist.

[0019] <Support Film> The support film is a layer or film for supporting the photosensitive resin layer, and is preferably a transparent substrate that transmits actinic rays. Examples of transparent substrates include synthetic resins such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate. Among these, polyethylene terephthalate (PET) is preferably used 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, even more preferably 0.1 or less, and most preferably 0.08 (e.g., 0.080) or less. The absorbance may be 0 or more.

[0020] It is preferable to use a film with few internal foreign matters, i.e., a high-quality film, as the support film. Specifically, it is more preferable to use, as the high-quality film, a PET film synthesized using a Ti-based catalyst, a PET film with a small diameter and low content of lubricant, a PET film containing lubricant on only one side of the film, a thin PET film, a PET film smoothed on at least one side, and a PET film roughened on at least one side by plasma treatment, etc. This makes it easier for the exposure light to be irradiated onto the photosensitive resin layer without being blocked by internal foreign matters, and therefore the resolution of the photosensitive resin laminate is easily improved.

[0021] The thickness of the support film is preferably 5 to 25 μm, more preferably 6 to 20 μm. The thinner the support film, the fewer internal foreign matter tends to be present, making it easier to prevent a decrease in resolution. On the other hand, if the film thickness is less than 5 μm, stretching deformation in the winding direction due to tension during the coating and winding manufacturing process is likely to occur, and tearing due to minute scratches is also likely to occur. As a result, the film is likely to lack strength and therefore is prone to wrinkles during lamination. At least one side of the support film may be subjected to a smoothing treatment using a calender or the like. This reduces the surface roughness of one side of the support film, particularly the side that comes into contact with the photosensitive resin layer, making it easier to achieve the effects of the present invention.

[0022] 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%, from the viewpoint of improving the parallelism of the light beam irradiated onto the photosensitive resin layer and from the viewpoint of obtaining high resolution.

[0023] <Photosensitive Resin Layer> The photosensitive resin layer contains a photosensitive resin composition. The photosensitive resin composition contains "(A) an alkali-soluble polymer," "(B) a compound having an ethylenically unsaturated bond," and "(C) a photopolymerization initiator." The photosensitive resin composition may contain "(D) a polymerization inhibitor." In this specification, the above components (A) to (D) may be simply referred to as "component (A)" to "component (D)." The components (A) to (D) or the raw materials for these components may be used alone, or two or more types may be used in combination. Furthermore, with regard to components that may be optionally contained (other components), when they are contained, they may be used alone, or two or more types may be used in combination.

[0024] The thickness of the photosensitive resin layer is preferably 3 to 100 μm, and specifically preferred film thicknesses include 7 μm, 15 μm, 25 μm, 40 μm, and 60 μm. A more preferred upper limit is 50 μm. As the thickness approaches 3 μm, the resolution is more likely to improve, and as the thickness approaches 100 μm, the film strength is more likely to improve. When the formed resist pattern is used in a plating formation process, the film thickness is preferably 10 to 30 μm, and more preferably 15 to 25 μm. To be more suitable for miniaturized 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.

[0025] Component (A): Alkali-Soluble Polymer The component (A) includes the copolymer (A-1) described below. The component (A) may include a copolymer (other copolymer) other than the copolymer (A-1), and such other copolymer preferably includes a repeating unit composed of at least one first monomer described below, and preferably includes a repeating unit composed of at least one first monomer and at least one second monomer described below.

[0026] The first monomer is a monomer having a carboxyl group and at least one ethylenically unsaturated bond in the 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, and methacrylic acid is more preferred, from the viewpoints of excellent adhesion and resolution.

[0027] The content of the first monomer in component (A) is preferably 10 to 50% by mass, based on the total mass of all monomer components. A content of 10% by mass or more is preferred from the viewpoint of excellent developability and resolution. From the same viewpoint, the content is more preferably 15% by mass or more, even more 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. A content of 50% by mass or less is preferred from the viewpoint of excellent adhesion and flexibility. From the same viewpoint, the content is more preferably 35% by mass or less, even more preferably 30% by mass or less, particularly preferably 29% by mass or less, and most preferably 27% by mass or less. When two or more first monomers are used, it is preferred that the total content of each be within the above range.

[0028] The second monomer is a non-acidic monomer having at least one ethylenically unsaturated bond in the molecule. The content of the second monomer in component (A) is preferably 50 to 90 mass% based on the total mass of all monomer components. In one embodiment, this content may be understood as the content of components other than the first monomer in component (A).

[0029] The component (A) contains a compound having an aromatic structure as a second monomer. The component (A) having a structural unit derived from such a compound makes it easier to suppress swelling of the photosensitive resin layer during development, thereby making it possible to obtain a photosensitive resin layer with excellent adhesion, resolution, and the like.

[0030] The content of structural units derived from compounds having an aromatic structure in component (A) 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, the 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, it is preferable to set the content to 85% by mass or less, and from the same viewpoint, it is more preferable that it be 80% by mass or less. When two or more compounds having an aromatic structure are used as the second monomer, it is preferable that the total content of structural units derived from each compound be within the above range.

[0031] Examples of compounds having an aromatic structure include benzyl (meth)acrylate, styrene, styrene derivatives (methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, styrene dimer, styrene trimer, etc.), phenoxyethyl (meth)acrylate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl (meth)acrylate, etc. 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 to 85% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass, based on the total mass of all monomer components.

[0032] It is also preferable that the compound having an aromatic structure contains both styrene and benzyl (meth)acrylate. The content of benzyl (meth)acrylate is preferably 1 to 60 mass%, more preferably 5 to 50 mass%, and even more preferably 10 to 35 mass%, based on the total mass of all monomer components, whether used in combination with styrene or not.

[0033] In this embodiment, the component (A) includes the following component: (A-1) a copolymer containing structural units derived from a compound having a hydroxyl group (particularly, a hydroxyalkyl (meth)acrylate) and having a weight-average molecular weight of 25,000 or less. This makes it possible to obtain a photosensitive resin layer with excellent developability and resolution. Here, in this embodiment, the component (A) as a whole contains a relatively large amount of structural units derived from a compound having an aromatic ring, and the above-mentioned (A-1) copolymer is selected from the perspective of achieving a balance with this aspect and satisfying various properties. That is, according to this embodiment, by selecting the above-mentioned (A-1) copolymer while obtaining the contribution (e.g., excellent adhesion) of the "structural units derived from a compound having an aromatic ring," it is possible to achieve a balance between the developability of the photosensitive resin layer and the adhesion and resolution of the obtained resist pattern, and these properties can be satisfied.

[0034] In the copolymer (A-1), the structural unit derived from a compound having a hydroxyl group may be derived from either the first monomer or the second monomer. However, from the viewpoint of facilitating the realization of the copolymer (A-1), it is preferable that the second monomer contains a compound having a hydroxyl group. The second monomer may contain both a compound having an aromatic structure and a compound having a hydroxyl group.

[0035] Furthermore, when the component (A) contains a copolymer other than the copolymer (A-1), the other copolymer may also contain a structural unit derived from a compound having a hydroxyl group.

[0036] The compound having a hydroxyl group is a compound having an alcoholic hydroxyl group, and in particular, a hydroxyalkyl (meth)acrylate. 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 compounds are relatively easy to obtain, and yet they facilitate control of the developability of the photosensitive resin layer, making it easy to realize a resist pattern with excellent adhesion and resolution.

[0037] From the viewpoint of excellent developability and adhesion, the content of the hydroxyl group-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 monomer components. When two or more types of compounds having a hydroxyl group are used, it is preferable that the total content of each of them be within the above range.

[0038] The second monomer may further contain a polymerizable compound different from either a compound having an aromatic structure or a compound having a hydroxyl group. Examples of the polymerizable compound different from either a compound having an aromatic structure or a compound having a hydroxyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, and nonylphenoxypropyl. (meth)acrylates such as triethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol (meth)acrylate, methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, and 3,3,5-trimethylcyclohexyl (meth)acrylate; esters of vinyl alcohol such as vinyl acetate; and (meth)acrylonitrile.

[0039] The component (A) may contain a copolymer different from the copolymer (A-1). The copolymer different from the copolymer (A-1) may have a weight-average molecular weight that is larger than, smaller than, or comparable to the weight-average molecular weight of the copolymer (A-1).

[0040] The weight-average molecular weight of the entire component (A) is preferably 10,000 or more and less than 30,000. A weight-average molecular weight of less than 30,000 is preferable from the viewpoint of achieving a balance between adhesion, resolution, and developability and satisfying these requirements. As shown in the examples, which are one aspect of this embodiment, an embodiment in which the weight-average molecular weight of the entire component (A) is 30,000 does not provide satisfactory results for some of the properties evaluated in the examples. An embodiment in which the weight-average molecular weight of the entire component (A) is 20,000 provides satisfactory results for some of the properties evaluated in the examples. However, in order to achieve a low molecular weight for the entire component (A), the weight-average molecular weight of the component (A) is preferably between 20,000 and 30,000, i.e., more preferably 25,000 or less. Furthermore, the weight-average molecular weight of the component (A) is more preferably 23,000 or less, and particularly preferably 21,000 or less. Furthermore, from the standpoint of preventing elution of the resist pattern in the water washing step after development, the weight average molecular weight of the entire component (A) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 17,000 or more.

[0041] The polydispersity of component (A) is preferably from 1.0 to 6.0, more preferably from 1.0 to 5.0, even more preferably from 1.0 to 4.0, and particularly preferably from 1.0 to 3.0.

[0042] In this embodiment, the component (A) may consist of only one type of copolymer, or may consist of two or more types of copolymers. When the component (A) consists of only one type of copolymer, that one type of copolymer is copolymer (A-1), and the content of each structural unit is the proportion of the compound constituting each structural unit. When the component (A) consists of two or more types of copolymers, the content of each structural unit represents a weighted average of the proportion of the compound constituting each structural unit, with the ratio of the content of each copolymer as the weight. When the component (A) consists of two or more types of copolymers, it is preferable that the molecular weight and polydispersity are selected so that the weighted average, with the ratio of the content of each copolymer as the weight, falls within the above range.

[0043] The synthesis of component (A) is preferably carried out by adding an appropriate amount of a radical polymerization initiator such as benzoyl peroxide or azoisobutyronitrile to a solution obtained by diluting one or more of the monomers described above with a solvent such as acetone, methyl ethyl ketone, or isopropanol, and then heating and stirring the mixture. The synthesis may be carried out while adding a portion of the mixture dropwise to the reaction solution. After the reaction is complete, further solvent may be added to adjust the concentration to the desired level. In addition to solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization may also be used as a synthesis method. The synthesis may also be carried out by living radical polymerization.

[0044] The content of component (A) may be 40% by mass or more, preferably 50% by mass or more, and more preferably 55% by mass or more, based on the total solid content of the photosensitive resin composition, and may be 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0045] It is preferable to set the content of the component (A) relative to the total solid content of the photosensitive resin composition to 90% by mass or less from the viewpoint of controlling the development time, and it is preferable to set the content of the component (A) to 40% by mass or more from the viewpoint of suppressing bleeding of the photosensitive resin layer from the edge surfaces of the film and of suitably exhibiting the effects exerted by the component (A).

[0046] The photosensitive resin composition of this embodiment contains the above-mentioned copolymer (A-1) as component (A). The copolymer (A-1) may be composed of only one type of copolymer or two or more types of copolymers, as long as it contains a structural unit derived from a compound having a hydroxyl group (particularly, a hydroxyalkyl (meth)acrylate) and has a weight-average molecular weight of 25,000 or less.

[0047] From the viewpoint of excellent developability and resolution, it is preferable that the weight average molecular weight of the copolymer (A-1) is 25,000 or less. From the same viewpoint, the weight average molecular weight is preferably 23,000 or less, more preferably 21,000 or less. Furthermore, from the viewpoint of suppressing exudation of the photosensitive resin layer from the edge of the film, the 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 copolymer (A-1) has repeating units composed of at least one of the first monomers and at least one of the second monomers.

[0048] The (A-1) copolymer may contain, as the first monomer, one of those described above in "Component (A): Alkali-Soluble Polymer," and preferably contains (meth)acrylic acid. 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. A proportion of 10% by mass or more is preferred from the viewpoint of excellent developability and resolution, and from the same viewpoint, a proportion of 15% by mass or more is more preferred, 18% by mass or more is even more preferred, 21% by mass or more is even more preferred, 23% by mass or more is particularly preferred, and 25% by mass or more is most preferred. A content of 50% by mass or less is preferred from the viewpoint of excellent adhesion and resolution, and is more preferably 35% by mass or less, more preferably 30% by mass or less, particularly preferably 29% by mass or less, and most preferably 27% by mass or less. When two or more first monomers are used, it is preferred that the total content of each of the first monomers be within the above range.

[0049] The copolymer (A-1) contains a compound having a hydroxyl group as a second monomer. By containing a structural unit derived from the compound having a hydroxyl group, excellent developability and resolution are achieved. The compound having a hydroxyl group is a compound containing an alcoholic hydroxyl group, and in particular, a hydroxyalkyl (meth)acrylate. Examples of the hydroxyalkyl (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Of these, 2-hydroxyethyl methacrylate is particularly preferred.

[0050] From the viewpoint of excellent developability and adhesion, the proportion of the compound having a hydroxyl group in the copolymer (A-1) is preferably 1.0 to 20 mass%, more preferably 1.0 to 10 mass%, and even more preferably 1.0 to 6.0 mass%, based on the total mass of all monomer components. When two or more types of compounds having a hydroxyl group are used, the total proportion of each compound preferably falls within the above range.

[0051] The (A-1) copolymer preferably contains a compound having an aromatic structure as the second monomer. The (A-1) copolymer has a structural unit derived from such a compound, which makes it easier to suppress swelling of the photosensitive resin layer during development, and thus makes it easier to obtain a photosensitive resin layer that is excellent in adhesion, resolution, and the like. Examples of the compound having an aromatic structure include those described above in "Component (A): Alkali-Soluble Polymer," and among these, benzyl (meth)acrylate and / or styrene are preferred.

[0052] From the viewpoint of suppressing swelling of the resist pattern in a developer after exposure and thereby improving resolution and adhesion, the proportion of structural units derived from a compound having an aromatic structure in the copolymer (A-1) is preferably 50 to 90 mass%, more preferably 55 to 80 mass%, and even more preferably 60 to 75 mass%, based on the total mass of all monomer components. When two or more compounds having a compound having an aromatic structure are used, it is preferable that the total copolymerization proportion of each of them be within the above range.

[0053] When the component (A) contains a copolymer other than the copolymer (A-1) (other copolymer), the other copolymer may contain a compound having an aromatic structure. That is, the compound having an aromatic structure may be contained in the copolymer (A-1), the other copolymer, or both. When the component (A) contains the other copolymer, the content of structural units derived from a compound having an aromatic ring in the component (A) is 50 mass% or more based on the total mass of all monomer components. Note that when the component (A) contains the other copolymer, the other copolymer may be one type or multiple types.

[0054] From the viewpoint of suitably exerting the effects of this embodiment, the content of the copolymer (A-1) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and may be 100% by mass, based on the total amount of the component (A). From the same viewpoint, the content of the copolymer (A-1) is preferably 20 to 90% by mass, more preferably 25 to 70% by mass, and even more preferably 30 to 60% by mass, based on the total solid content in the photosensitive resin composition.

[0055] Component (B): Compound Having an Ethylenically Unsaturated Bond Component (B) is a compound having at least one ethylenically unsaturated bond per molecule. The content of component (B) is preferably 30% by mass or more, more preferably 35% by mass or more, based on the total solid content of the photosensitive resin composition, from the viewpoint of excellent sensitivity, tackiness, and followability. Furthermore, from the viewpoint of excellent edge fusion property, tackiness, and resolution, the 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 fusion property refers to the tendency of the resist to overflow during storage of the photosensitive element roll, and the smaller the amount of overflow, the better. Tackiness refers to the adhesiveness of the photosensitive resin composition. In order to prevent poor lamination to the substrate and to prevent poor peeling of the protective film and the support film, it is preferable that the adhesiveness of the photosensitive resin composition be appropriate.

[0056] In this embodiment, the photosensitive resin composition preferably contains a compound having two ethylenically unsaturated bonds in one molecule as component (B), from the viewpoint of providing a photosensitive resin layer after exposure with appropriate flexibility and excellent flex resistance. Furthermore, the photosensitive resin composition may further contain a compound having three ethylenically unsaturated bonds in one molecule, or may further contain a compound having four, five, or six ethylenically unsaturated bonds in one molecule, from the viewpoint of providing excellent crosslinking efficiency in the exposure step.

[0057] The content of the compound having two ethylenically unsaturated bonds in one molecule 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 (B), from the viewpoint of excellent releasability, resolution, and adhesion. The content may be 100% by mass.

[0058] When a compound having three or more ethylenically unsaturated bonds is included, from the viewpoint of improving the crosslinking efficiency in the exposure step and thereby improving adhesion, the content of the compound having three or more ethylenically unsaturated bonds may be 1 to 50 mass%, 1 to 25 mass%, or 1 to 15 mass%, based on the total amount of the component (B).

[0059] The component (B) preferably contains a compound containing a (meth)acryloyl group (hereinafter referred to as a (meth)acrylate compound). With regard to the component (B), "a (meth)acrylate compound having n (meth)acryloyl groups in one molecule" is referred to as, for example, "n-functionality." For example, with regard to the component (B), having one, two, three, four, five, or six ethylenically unsaturated bonds in one molecule is referred to as "monofunctional (or monofunctional)," "bifunctional," "trifunctional," "tetrafunctional," "pentafunctional," or "hexafunctional," respectively.

[0060] Examples of bifunctional (meth)acrylate compounds include alkyl di(meth)acrylate, 1,3-bis(meth)acryloyloxy-2-propanol, polyalkylene glycol di(meth)acrylate, and di(meth)acrylate having a bisphenol A structure. Here, the term "bisphenol A structure" is a concept that includes a hydrogenated bisphenol A structure.

[0061] Examples of polyalkylene glycol di(meth)acrylate 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): (In the formula, R １ are each independently a hydrogen atom or a methyl group, and X １ O and Y １O are each independently an oxyethylene group or an oxypropylene group, (X １ O) m1, (X １ O) m2, (Y １ O) n1 is a (poly)oxyethylene chain or a (poly)oxypropylene chain, m1, m2, and n1 are each independently an integer of 0 to 40, m1+m2 is 1 to 40, and n1 is 1 to 20.

[0062] The di(meth)acrylate having a bisphenol A structure includes a di(meth)acrylate represented by the general formula (II): (In the formula, R ２ are each independently a hydrogen atom or a methyl group, and X ２ O and Y ２ O are each independently an oxyethylene group or an oxypropylene group, m3, m4, n2, and n3 are each independently an integer of 0 to 40, m3+m4 is 1 to 40, and n2+n3 is 0 to 20.

[0063] In the di(meth)acrylate compound having a bisphenol A structure represented by general formula (II), the average value of n2 + n3 + m3 + m4 is preferably 20 or less, and more preferably 10 or less, from the viewpoints of resolution and adhesion. The average value of n2 + n3 + m3 + m4 may be 2 or more. The number of repeating units of oxyethylene groups or oxypropylene groups is an integer value in a single molecule, and is a rational number that is the average value in an aggregate of multiple molecules.

[0064] Furthermore, examples of the di(meth)acrylate having a hydrogenated bisphenol A structure include compounds in which hydrogen is added to the aromatic ring of the compound represented by formula (II).

[0065] The polyalkylene glycol di(meth)acrylate represented by formula (I) includes R １ = methyl group, m1 + m2 = 6 (average value), n1 = 12 (average value), X １ O is an oxyethylene group, Y １ Examples include a vinyl compound in which O is an oxypropylene group (manufactured by Hitachi Chemical Co., Ltd., product name "FA-024M").

[0066] As the di(meth)acrylate compound having a bisphenol A structure represented by general formula (II), BPE-200 (R ２ = methyl group, X ２ O = oxyethylene group, m3 + m4 = 4, n2 = n3 = 0) BPE-500 (R ２ = methyl group, X ２ O = oxyethylene group, m3 + m4 = 10, n2 = n3 = 0), BPE-900 (R ２ = methyl group, X ２ O = oxyethylene group, m3 + m4 = 17, n2 = n3 = 0) (all of these are product names manufactured by Shin-Nakamura Chemical Co., Ltd.), FA-321M (R ２ = methyl group, X ２ O = oxyethylene group, m3 + m4 = 10, n2 = n3 = 0), FA-P321M (R ２ = methyl group, X ２ O = oxypropylene group, m3 + m4 = 10, n2 = n3 = 0) (all of these are product names manufactured by Resonac Co., Ltd.).

[0067] Commercially available bifunctional (meth)acrylate compounds include, for example, NK Ester (registered trademark) A-HD-N, A-NOD-N, A-DOD-N, A-NPG, 701A, A-200, A-400, A-600, A-1000, APG-200, APG-400, APG-700, A-PTMG65, A-DCP, ABE-300, A-BPE-4, A-BPE-10, A-BPE-20, HD-N, NOD- N, DOD-N, NPG, 701, 2G, 3G, 4G, 9G, 14G, 23G, 9PG, DCP, BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N, NK Oligo (registered trademark) UA-4200, UA-160TM, UA-290TM, UA-W2A, UA-4400, UA-122P, U-200PA (manufactured by Shin-Nakamura Chemical Co., Ltd.), Light Acrylate (registered trademark) 3EG-A, 4EG-A, 9EG-A, 14EG-A, PTMGA-250, NP-A, MPD-A, 1.6HX-A, 1.9ND-A, DCP-A, BP-4EAL, BP-4PA, HPP-A, Light Ester G-201P (all manufactured by Kyoeisha Chemical Co., Ltd.), Fancryl (registered trademark) FA-124AS, FA-023M, FA-121M, FA-124M, FA-125M, FA-12 9AS, FA-137M, FA-220M, FA-222A, FA-240A, FA-240M, FA-320M, FA-3218M, FA-321A, FA-321M, FA-324A, FA-731A, FA-P240A, FA-P270A, FA-PTG9A, FA-PTG9M, FA-PTG28A, 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 Daicel Allnex Co., Ltd.), 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) Examples of such PEG-10 ...

[0068] Examples of trifunctional or higher functional (meth)acrylate compounds include trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, isocyanuric acid tri(meth)acrylate, pentaerythritol (tri / tetra)(meth)acrylate, diglycerin (tetra)(meth)acrylate, ditrimethylolpropane (tetra / penta / hexa)(meth)acrylate, triglycerin (penta)(meth)acrylate, and dipentaerythritol (tetra / penta / hexa)(meth)acrylate.

[0069] The tri- or higher functional (meth)acrylate compound may also be a compound obtained by forming a (meth)acrylate from (meth)acrylic acid and an alcohol having, as a central skeleton, three or more groups to which alkylene oxide groups can be added within the molecule, and having an alkylene oxide group such as an ethylene oxide group, a propylene oxide group, or a butylene oxide group added to the central skeleton. Examples thereof include alkylene oxide-modified tri(meth)acrylate of trimethylolpropane, alkylene oxide-modified tri(meth)acrylate of glycerin, alkylene oxide-modified isocyanuric acid tri(meth)acrylate, alkylene oxide-modified pentaerythritol (tri / tetra)(meth)acrylate, alkylene oxide-modified tetra(meth)acrylate of diglycerin, alkylene oxide-modified ditrimethylolpropane (tetra / penta / hexa)(meth)acrylate, alkylene oxide-modified penta(meth)acrylate of triglycerin, and alkylene oxide-modified dipentaerythritol (tetra / penta / hexa)(meth)acrylate.

[0070] The compound having a tri- or higher functional ethylenically unsaturated bond may contain, from the viewpoint of adhesion, an alkylene oxide-modified pentaerythritol (tri / tetra)(meth)acrylate and / or an alkylene oxide-modified dipentaerythritol (tri / tetra)(meth)acrylate.

[0071] Commercially available compounds having a trifunctional or higher ethylenically unsaturated bond include, for example, NK Ester (registered trademark) A-TMPT, A-TMPT-9EO, AT-20E, A-GLY-3E, A-GLY-9E, A-GLY-20E, A-9300, A-9200YN, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, A-TMMT, ATM-35E, AD-TMP, A-DPH, and A-9. 550, A-DPH-12E, TPOA-50, NK Oligo (registered trademark) UA-7100, UA-1100H, U-6LPA, UA-33H, U-10HA, U-10PA, U-15HA (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Light Acrylate (registered trademark) TMP-A, cPE-3A, PE-4A, DPE-6A (all manufactured by Kyoeisha Chemical Co., Ltd.), FA-731A (manufactured by Resonac Co., Ltd.), TMPTA, EBECRYL 160S, OTA 480, PETIA, PETRA, EBECRYL 40, PETA, EBECRYL 140, EBECRYL 1140, EBECRYL 1142, DPHA, EBECRYL 895, EBECRYL 896, EBECRYL TMPTMA (all manufactured by Daicel-Allnex Co., Ltd.), 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, TMPTA, THE-330, TPA-330, PET-30, T-1420(T), RP-1040, DPHA, DPEA-12, D-310, DPCA-20 (all manufactured by Nippon Kayaku Co., Ltd.), and the like.

[0072] The component (B) preferably contains the following component: (b1) a compound having two ethylenically unsaturated bonds per molecule and having an ethylenically unsaturated bond concentration of 0.0020 mol / g or more. This makes it easy to simultaneously achieve a dense crosslinked structure formed by exposure and a photosensitive resin layer with appropriate toughness. Therefore, even when the weight-average molecular weight of the component (A) is relatively small, it is easy to ensure adhesion of the resist pattern. In addition, it is easy to prevent elution of the component (A) from the cured resist pattern during the water washing step after development.

[0073] In the compound contained in the component (b1), from the viewpoint of ensuring the adhesion of the resist pattern, the concentration of the ethylenically unsaturated bond is preferably 0.0022 mol / g or more, and even more preferably 0.0024 mol / g or more. In addition, 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 the ethylenically unsaturated bond of the compound contained in the component (b1) 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.

[0074] From the viewpoint of excellent releasability, resolution, and adhesion, the content of the (b1) component is preferably 50% by mass or more, 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 the (B) component.

[0075] The component (b1) is preferably a bifunctional (meth)acrylate compound, and more preferably a di(meth)acrylate having a bisphenol A structure or a polyalkylene glycol di(meth)acrylate. Examples of polyalkylene glycol di(meth)acrylate compounds that can be included in the component (b1) include: polyethylene glycol di(meth)acrylate compounds having 1 to 19 repeating ethylene glycol units; polypropylene glycol di(meth)acrylate compounds having 1 to 14 repeating propylene glycol units; and polytetramethylene glycol di(meth)acrylate compounds having 1 to 11 repeating tetramethylene glycol units.

[0076] Among di(meth)acrylates having a bisphenol A structure, examples of compounds contained in component (b1) include those represented by the following general formula (III): and / or a compound in which hydrogen is added to the aromatic ring of a compound represented by general formula (III), ２ is a methyl group or a hydrogen atom, and X ２ A compound in which O=oxyethylene group and m3+m4=2 to 14; and R ２ is a methyl group or a hydrogen atom, and X ２ Compounds in which O=oxypropylene group and m3+m4=2 to 13;

[0077] From the viewpoint of improving the reactivity of the photosensitive resin composition during exposure and increasing the density of the crosslinked structure formed, the component (b1) preferably contains a di(meth)acrylate compound having a bisphenol A structure, and in general formula (III), R ２ is a methyl group or a hydrogen atom, and X ２ It is more preferable that the compound contains a compound in which O=oxyethylene group and m3+m4=2 to 14, and in the general formula (III), ２ is a methyl group or a hydrogen atom, and X ２ It is more preferable that the compound contains a compound in which O=oxyethylene group and m3+m4=2 to 10.

[0078] The content of the di(meth)acrylate compound having a bisphenol A structure in the component (B) is preferably 25% by mass or more, more 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 the component (B). The content of the di(meth)acrylate compound having a bisphenol A structure in the 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 the component (b1). The above content may be 100% by mass, based on the total amount of the component (b1).

[0079] The concentration of ethylenically unsaturated bonds in the entire component (B) is preferably 0.0020 mol / g or more and 0.0050 mol / g or less. By being 0.0020 mol / g or more, the crosslinking density of the photosensitive resin layer during exposure can be favorably improved, and the photosensitive resin component can be easily prevented from leaching out of the cured resist pattern during the water washing step after development, which in turn can prevent contamination of the water washing step. By being 0.0050 mol / g or less, chipping and therefore dropping of the cured resist pattern during the water washing step after development is less likely to occur.

[0080] The concentration of ethylenically unsaturated bonds in the entire component (B) is preferably 0.0022 mol / g or more, and even more preferably 0.0024 / g or more, and more preferably 0.0045 / g or less, and even more preferably 0.0040 mol / g or less.

[0081] In this embodiment, the mass ratio (total content of component (A) / total content of component (B)) in the photosensitive resin composition is preferably 1.00 or more and 1.80 or less. When the above value is 1.00 or more, a photosensitive resin composition with excellent adhesion is easily obtained, and when the above value is 1.80 or less, a photosensitive resin composition with excellent developability and resolution is easily obtained. That is, when the value of the total content of component (A) / the total content of component (B) is within the above range, a photosensitive resin composition with an excellent balance of developability, adhesion, and resolution performance is easily obtained. In particular, from the viewpoint of easily obtaining a photosensitive resin composition with excellent adhesion, the value of the total content of component (A) / the total content of component (B) is more preferably 1.20 or more. From the same viewpoint, the above value is even more preferably 1.30 or more, and particularly preferably 1.40 or more.

[0082] When the ratio of the total content of the component (A) to the total content of the component (B) is 1.20 or more, the mechanism by which adhesion is improved without impairing developability and resolution is presumed to be as follows. In this embodiment, the component (A) includes an (A-1) copolymer that has a small weight-average molecular weight and includes a structural unit derived from a compound having a hydroxyl group (particularly a hydroxyalkyl (meth)acrylate). This makes it easy to achieve excellent developability even if the content of the structural unit having an aromatic ring in the component (A) is large. Therefore, even if the ratio of the total content of the component (A) to the total content of the component (B) is increased, developability is unlikely to be impaired, and the adhesive effect of the structural unit having an aromatic ring in the component (A) is easily maximized.

[0083] Component (C): Photopolymerization Initiator (First Component (C)) The first component (C) is a photopolymerization initiator having a biimidazole structure, and is a compound that initiates radical polymerization of the component (B) upon exposure to light.

[0084] The content of the first (C) component may be 3.0% by mass or more, preferably 4.0% by mass or more and more preferably 5.0% by mass or more, based on the total solid content of the photosensitive resin composition, from the viewpoint of excellent sensitivity and adhesion, and preferably 10% by mass or less, more preferably 8.0% by mass or less, and even more preferably 6.0% by mass or less, from the viewpoint of excellent solubility.

[0085] Examples of the first component (C) include dimers of compounds having a lophine structure (lophine dimers), i.e., dimers of 2,4,5-triarylimidazole. Examples of lophine dimers, i.e., dimers of 2,4,5-triarylimidazole, include dimers 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, and 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-di Phenylbiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbiimidazole, 2,2'-(o-chlorophenyl)-4,4',5,5'-tetrakis-(3,4-dimethoxyphenyl)-biimidazole, 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis- (3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4,2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, and 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole are examples thereof.

[0086] From the viewpoint of achieving excellent sensitivity, resolution, and adhesion, the first component (C) preferably contains a lophine dimer, and particularly preferably contains a 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer.

[0087] The component (C) is not limited to the above, and further examples include components.

[0088] (Second Component (C)) Examples of the second component (C) 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 ketal compounds, thioxanthone compounds, dialkylaminobenzoic acid ester compounds, oxime ester compounds, acridine compounds, pyrazoline derivatives, N-arylamino acid ester compounds, coumarin derivatives, and halogen compounds.

[0089] Examples of aromatic ketone compounds include benzophenone compounds. Examples of benzophenone compounds include benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4-methoxy-4'-dimethylaminobenzophenone. From the viewpoints of sensitization effect and adhesion, 4,4'-bis(diethylamino)benzophenone is preferred as the aromatic ketone compound.

[0090] In this specification, the term "anthracene derivative" means 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-anthraceneboronic acid. From the viewpoint of sensitization effect and adhesion, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, and 10-phenyl-9-anthraceneboronic acid are preferred, and 9,10-diphenylanthracene and 10-phenyl-9-anthraceneboronic acid are particularly preferred.

[0091] From the viewpoints of adhesion and rectangularity of the resist pattern, the pyrazoline derivatives are preferably 1-phenyl-3-(4-tert-butyl-styryl)-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, or 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline.

[0092] When the photosensitive resin composition contains the second component (C), from the viewpoint of storage stability, it preferably contains at least one of a benzophenone compound, a pyrazoline compound, an anthracene compound, and a coumarin compound, and more preferably contains at least one of a benzophenone compound and a pyrazoline compound.

[0093] The content of the second (C) component is preferably 0 to 0.5 mass%, more preferably 0 to 0.2 mass%, even more preferably 0 to 0.1 mass%, even more preferably 0 to 0.05 mass%, and particularly preferably 0 to 0.025 mass%, based on the total solids content of the photosensitive resin composition. Adjusting the content of the (D) component within the above range facilitates reducing absorbance in wavelength regions other than the exposure wavelength, thereby facilitating improved storage stability. The first (C) component and the second (C) component are preferably used in combination. The (C) components (the first (C) component and / or the second (C) component) are compounds that contribute to the promotion of photopolymerization reactions and may be treated as agents having photopolymerization initiation function or sensitizing function.

[0094] Component (D): Polymerization Inhibitor Examples of component (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-t-butyl-5-methyl-4-hydroxyphenyl)propionate], nitrosophenylhydroxyamine aluminum salt (e.g., aluminum salt with 3 moles of nitrosophenylhydroxylamine added), and diphenylnitrosamine. Of these, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] or aluminum salt with 3 moles of nitrosophenylhydroxylamine added is preferred.

[0095] From the viewpoint of storage stability, the component (D) preferably contains any one of phenothiazine, p-methoxyphenol, tert-butylcatechol, and 2,6-di-tert-butyl-p-cresol.

[0096] From the viewpoint of excellent resolution, the content of the component (D) is preferably 10 to 5,000 ppm, more preferably 50 to 1,000 ppm, and even more preferably 50 to 500 ppm, based on the total solid content of the photosensitive resin composition.

[0097] Other Components The photosensitive resin composition may contain other components (base dye, antioxidant, stabilizer, plasticizer, etc.) as desired.

[0098] Examples of base dyes include Basic Green 1 [CAS number (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Fuchsin [632-99-5], Methyl Violet [603-47-4], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], etc. Among these, Basic Green 1 is preferred from the viewpoint of improving colorability, hue stability, and exposure contrast.

[0099] The content of the base dye is preferably 0.001 to 3 mass %, more preferably 0.01 to 2 mass %, and even more preferably 0.04 to 1 mass %, based on the total solid content of the photosensitive resin composition. The content of the base dye is preferably equal to or greater than the above-mentioned lower limit from the viewpoint of obtaining good colorability, and on the other hand, is preferably equal to or less than the above-mentioned upper limit from the viewpoint of maintaining the sensitivity of the photosensitive resin layer.

[0100] Examples of antioxidants include triphenyl phosphite (e.g., manufactured by ADEKA Corporation under the trade name of TPP), tris(2,4-di-tert-butylphenyl) phosphite (e.g., manufactured by ADEKA Corporation under the trade name of 2112), tris(mononylphenyl) phosphite (e.g., manufactured by ADEKA Corporation under the trade name of 1178), and bis(mononylphenyl)-dinonylphenyl phosphite (e.g., manufactured by ADEKA Corporation under the trade name of 329K).

[0101] The content of the antioxidant is preferably 0.001 to 0.8% by mass, more preferably 0.01 to 0.3% by mass, based on the total solids content of the photosensitive resin composition. The content of the antioxidant is preferably equal to or greater than the lower limit described above, from the viewpoints of achieving good hue stability of the resist pattern and improving the sensitivity of the photosensitive resin layer. On the other hand, the content of the antioxidant is preferably equal to or less than the upper limit described above, from the viewpoints of achieving good hue stability while suppressing the color development of the resist pattern and improving adhesion.

[0102] The stabilizer can be used from the viewpoint of improving the thermal stability of the photosensitive resin composition. Examples of the stabilizer include at least one of an alkylene oxide compound having a glycidyl group and a benzotriazole compound. These can be used alone or in combination of two or more.

[0103] Examples of alkylene oxide compounds having a glycidyl group include neopentyl glycol diglycidyl ether (e.g., Epolite 1500NP, manufactured by Kyoeisha Chemical Co., Ltd.), nonaethylene glycol diglycidyl ether (e.g., Epolite 400E, manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2-mol adduct diglycidyl ether (e.g., Epolite 3002, manufactured by Kyoeisha Chemical Co., Ltd.), and 1,6-hexanediol diglycidyl ether (e.g., Epolite 1600, manufactured by Kyoeisha Chemical Co., Ltd.). These can be used alone or in combination of two or more.

[0104] Examples of the benzotriazole compound include carboxylbenzotriazole, 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.

[0105] The total content of the antioxidant, the alkylene oxide compound having a glycidyl group, and the benzotriazole compound in the photosensitive resin composition is preferably 0.001 to 3 mass %, more preferably 0.05 to 1 mass %, based on the total solid content of the photosensitive resin composition.

[0106] In this embodiment, a color-forming dye that develops color upon irradiation with light may be included in the photosensitive resin composition. Known examples of color-forming dyes include a combination of a leuco dye and a halogen compound. Examples of leuco dyes include tris[(4-dimethylamino)phenyl]methane [leuco crystal violet] and bis[(4-dimethylamino)phenyl]phenylmethane [leucomalachite green]. Examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris(2,3-dibromopropyl)phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and hexachloroethane.

[0107] In this embodiment, the photosensitive resin composition may contain additives such as plasticizers as needed. Examples of additives include phthalate esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, triethyl acetyl citrate, tri-n-propyl acetyl citrate, tri-n-butyl acetyl citrate, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ether, and polypropylene glycol alkyl ether.

[0108] <Protective Film> The photosensitive resin laminate of this embodiment may include a protective film. The support film, the photosensitive resin layer, and the protective film may be laminated in this order. The protective film can 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.

[0109] When the adhesive strength between the photosensitive resin layer and the protective film is sufficiently weaker than the adhesive strength between the photosensitive resin layer and the support film, the protective film can be easily peeled off from the photosensitive resin layer. For example, polyethylene film, polypropylene film, oriented polypropylene film, polyester film, etc. can be preferably used as the protective film. In addition, a release layer may be provided on the surface of the protective film.

[0110] The thickness of the protective film is preferably 10 to 100 μm, more preferably 10 to 50 μm. Examples of the protective film include Alphan (registered trademark) EM-501, E-200, E-201F, FG-201, and MA-411 (all manufactured by Oji F-Tex Co., Ltd.), Torayfan (registered trademark) KW37, 2578, 2548, 2500, and YM17S, Therapeel (registered trademark) PJ271, PJ111, HP2, PJ101, WZ, MDA, MFA, TK07, BKE, BX8A, and SY (all manufactured by Toray Industries, Inc.), and GF-18, GF-818, and GF-858 (all manufactured by Tamapoly Co., Ltd.).

[0111] [Photosensitive Resin Laminate Roll] The photosensitive resin laminate may be in a long shape, or may be in a roll shape in which a long photosensitive resin laminate is wound around a core.

[0112] [Method for forming a resist pattern] The method for forming a resist pattern using the photosensitive resin laminate according to this embodiment includes the following steps, preferably in this order: a step of laminating the photosensitive resin laminate on a substrate; a step of exposing the photosensitive resin layer of the laminated photosensitive resin laminate; and a step of developing the photosensitive resin layer after exposure.

[0113] (Lamination Step) Specifically, in the lamination step, if the photosensitive resin laminate includes a protective film, the protective film is peeled off from the photosensitive resin laminate, and then the photosensitive resin layer is heat-pressed onto the surface of a support (e.g., a substrate) using a laminator, and laminated once or multiple times. Examples of materials for the substrate include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). The heating temperature during lamination is generally 40 to 160°C. Heat-pressure bonding can be performed using a laminator equipped with rolls, or by repeatedly passing the laminate of the substrate and the photosensitive resin layer through the rolls several times. Heat-pressure bonding can be performed in a reduced pressure environment, if desired.

[0114] (Exposure Process) In the exposure process, the photosensitive resin layer is exposed using an exposure machine. The exposure can be carried out after peeling off the support, if desired. When exposure is carried out through a photomask, the exposure dose is determined by the illuminance of the light source and the exposure time, and may be measured using an actinometer. In the exposure process, direct imaging exposure may be carried out. In direct imaging exposure, exposure is carried out directly on the substrate using a drawing device without using a photomask. A semiconductor laser or an ultra-high pressure mercury lamp with a wavelength of 350 to 410 nm is used as the light source. When the drawing pattern is controlled by a computer, the exposure dose is determined by the illuminance of the exposure light source and the moving speed of the substrate.

[0115] The light irradiation method used in the exposure step is preferably at least one method selected from the group consisting of projection exposure, proximity exposure, contact exposure, direct imaging exposure, and electron beam direct writing, and is more preferably performed by the projection exposure method or the direct imaging exposure method.

[0116] A heating step may be performed between the exposure step and the development step. 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. By performing this heating step, it is possible to improve resolution and adhesion. For heating, a hot air, infrared, or far-infrared heating furnace, a thermostatic oven, a hot plate, a hot air dryer, an infrared dryer, a hot roll, or the like can be used.

[0117] The time elapsed from the exposure step to the heating step, more precisely the time elapsed from the time exposure is stopped to the time heating is started, is preferably 10 to 600 seconds, more preferably 20 to 300 seconds. The time elapsed from the time heating is started to the time heating is stopped is preferably 1 to 120 seconds, more preferably 5 to 60 seconds.

[0118] (Development step) In the development step, the unexposed or exposed areas of the photosensitive resin layer after exposure are removed with a developer using a developing device. If a support film is present on the photosensitive resin layer after exposure, it is removed. Then, the unexposed or exposed areas are developed and removed using a developer consisting of an alkaline aqueous solution to obtain a resist image.

[0119] The alkaline aqueous solution is Na ２ CO ３ , K. ２ CO ３ The alkaline aqueous solution is selected depending on the properties of the photosensitive resin layer, but a Na solution having a concentration of 0.2 to 2% by mass is preferred. ２ CO ３ An aqueous solution is generally used. The aqueous alkaline solution may contain a surfactant, an antifoaming agent, a small amount of an organic solvent to promote development, etc. The temperature of the developer in the development step is preferably kept constant within the range of 20 to 40°C.

[0120] The development step preferably includes a water washing step for removing the developer contained in the resist pattern after development. The washing water may be pure water, industrial water, or other water selected according to the properties of the photosensitive resin layer. In order to improve the resolution and the shape of the resist pattern, MgSO at a concentration of 0.001 to 1% by mass is preferably used. ４ It is also possible to add polyvalent metal salts such as the following. The temperature of the washing water in the washing step is preferably kept constant within the range of 20 to 40°C.

[0121] A resist pattern can be obtained by the above steps, but if desired, a heating step can be further carried out at 60 to 300°C. By carrying out this heating step, the chemical resistance of the resist pattern can be improved. For the heating step, a heating furnace using hot air, infrared rays, or far infrared rays can be used.

[0122] To obtain a conductive pattern, a conductive pattern forming step may be carried out after the developing step or heating step, in which the substrate on which the resist pattern has been formed is etched or plated.

[0123] The method for producing a conductor pattern is carried out, for example, by using a metal plate or a metal-coated insulating plate as a substrate, forming a resist pattern by the above-mentioned resist pattern formation method, and then carrying out a conductor pattern formation step in which a conductor pattern is formed on the substrate surface (e.g., copper surface) exposed by development using a known etching method or plating method.

[0124] Furthermore, after producing a conductor pattern by the above-mentioned method for producing a conductor pattern, a peeling step can be carried out in which the resist pattern is peeled off from the substrate using an aqueous solution that is more alkaline than the developer, thereby obtaining a wiring board (e.g., a printed wiring board) having a desired wiring pattern.

[0125] The alkaline aqueous solution used for stripping (hereinafter also referred to as "stripping solution") is not particularly limited, but an aqueous solution of NaOH or KOH with a concentration of 2 to 5% by mass, or an organic amine-based stripping solution is generally used. A small amount of a water-soluble solvent may be added to the stripping solution. Examples of the water-soluble solvent include alcohol. The temperature of the stripping solution in the stripping step is preferably within the range of 40 to 70°C.

[0126] In this embodiment, the photosensitive resin laminate can be used in the manufacture of printed wiring boards, the manufacture of lead frames for mounting IC chips, precision processing of metal foils such as the manufacture of metal masks, the manufacture of packages such as ball grid arrays (BGAs) and chip size packages (CSPs), the manufacture of tape substrates such as chip-on-film (COFs) and tape automated bonding (TABs), the manufacture of semiconductor bumps, and the manufacture of partition walls of flat panel displays such as ITO electrodes, address electrodes, and electromagnetic wave shields. Unless otherwise specified, the values ​​of the above-mentioned parameters are measured in accordance with the measurement methods in the examples described below.

[0127] The present embodiment will be described below with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples. Regarding the examples and comparative examples, various productions, measurements, evaluations, etc. were carried out by the following methods.

[0128] Example 1 Synthesis of Component (A) As shown in the table below, predetermined monomers (copolymerization components) were mixed with azobisisobutyronitrile in predetermined amounts (unit: parts by mass) to prepare solution (a). 200 parts by mass of methyl ethyl ketone and 100 parts by mass of ethanol were placed in a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel, and nitrogen gas inlet tube, and the mixture was stirred while blowing nitrogen gas into the flask and heated to 80°C. Next, 100 parts by mass of the solution (a) was added dropwise to the flask at a constant rate over 4 hours, followed by stirring at 80°C for 2 hours.

[0129] Next, 0.5 parts by mass of azobisisobutyronitrile was dissolved in 50 parts by mass of a mixture of 30 parts by mass of methyl ethyl ketone and 20 parts by mass of ethanol to prepare solution (b). Solution (b) was added dropwise to the flask at a constant rate over 10 minutes, followed by stirring at 80°C for 3 hours. The mixture in the flask was then heated to 90°C over 30 minutes, and then kept at 90°C for 2 hours with stirring. After this, stirring was 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 the alkali-soluble polymers A1 to A9 are shown in the table.

[0130] The weight average molecular weight was measured by gel permeation chromatography (GPC) and calculated by conversion using a calibration curve of standard polystyrene. The GPC conditions were as follows: (GPC conditions) Pump: PU-4580 manufactured by JASCO Degasser: DG-2080-53 Column oven: CO-1560 Columns: Total of four columns: KF-807 x 1, KF-806M x 2, KF-802.5 x 1 manufactured by Shodex Eluent: Tetrahydrofuran Measurement temperature: 40°C Flow rate: 1.00 mL / min Detector: RI-1530 manufactured by JASCO

[0131] <Preparation of photosensitive resin layer and photosensitive resin laminate> The components shown in the table below were mixed in the amounts shown in the table below (the number for each component is the amount of solid content (unit: parts by mass)). Methyl ethyl ketone measured to give a solid content concentration of 60% was then added and thoroughly stirred to obtain a prepared solution of a photosensitive resin composition. The amount (parts by mass) shown in the table below is the mass of non-volatile content (solid content).

[0132] A 16 μm thick polyethylene terephthalate film (QS71, manufactured by Toray Industries, Inc.) was prepared as a support film. The above-mentioned preparation was uniformly applied to the surface of the support film using a bar coater, and then dried for a predetermined time in a dryer at 95°C. This resulted in a photosensitive resin laminate having a photosensitive resin layer of a predetermined thickness on the support film. The photosensitive resin laminates of Examples 1 to 24 and Comparative Examples 1 to 3 had a photosensitive layer thickness of 25 μm and a drying time of 2 minutes 30 seconds. The photosensitive resin laminate of Example 25 had a photosensitive layer thickness of 15 μm and a drying time of 1 minute 30 seconds. The photosensitive resin laminate of Example 26 had a photosensitive layer thickness of 7 μm and a drying time of 45 seconds.

[0133] Next, a 19 μm thick polyethylene film (GF-818, manufactured by Tamapoly Co., Ltd.) was attached as a protective film to 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 was treated as a photosensitive resin laminate (Example).

[0134] It was confirmed that by using the photosensitive resin laminate of the above example, it was possible to suitably realize both a resist pattern forming method and a wiring board forming method by conventional methods.

[0135] [Measurement, Evaluation, etc.] <Surface Preparation of Substrate> The surface of a copper clad laminate having a total thickness of 0.4 mm and having a rolled copper foil of 18 μm thickness on the surface was polished with 10% by mass H ２ SO ４ The copper clad laminate was washed with an aqueous solution and then with pure water. The washed copper clad laminate was preheated to 50°C.

[0136] <Lamination step> While peeling off the protective film from the photosensitive resin laminate, the photosensitive resin layer was laminated at a roll temperature of 105°C using a hot roll laminator (AL-700, manufactured by Asahi Kasei Corporation) so that the photosensitive resin layer was in contact with the surface of a copper-clad laminate preheated to 50°C. This produced a substrate for evaluation. The air pressure during lamination was set to 0.35 MPa, and the lamination speed was set to 1.5 m / min.

[0137] <Exposure Step> Two hours after lamination, the evaluation substrate was exposed to light at a wavelength of 365 nm using a predetermined mask pattern for projection exposure with a projection exposure machine (UX-2003SM-AGG01, manufactured by Ushio Inc.).

[0138] <Heating Step> One minute after exposure, the evaluation substrate was heated for 30 seconds using a constant temperature incubator (manufactured by Yamato Scientific Co., Ltd., DKM600) set at 60°C.

[0139] <Developing Step> The support film was peeled off from the photosensitive resin layer. Thereafter, the photosensitive resin layer was developed using an alkaline developer (manufactured by Fuji Kiko Co., Ltd., a dry film developer) with 1% by mass Na at 30°C under a spray pressure of 0.15 Pa. ２ CO ３ The photosensitive resin layer was developed using an aqueous solution for a predetermined time. Thereafter, the photosensitive resin layer was washed by spraying pure water onto the photosensitive resin layer for a predetermined time. This resulted in a resist pattern being formed on the evaluation substrate.

[0140] <Optimum Exposure Amount> Using a photomask having a mask pattern (see FIG. 1 ) with a line width (L) / space width (S) (hereinafter simply abbreviated as "L / S") of 8 / 8 (unit: μm), the evaluation substrate after the lamination step was exposed to light (exposure step). This was followed by a heating step and a development step, thereby forming a resist pattern on the evaluation substrate. The formed resist pattern was observed using an optical microscope at a magnification of 100x, and the line width of the pattern was thereby observed. The exposure amount (unit: mJ / cm ) at which the line width became 8 μm was determined. ２ ) was adopted as the optimum exposure amount, and the exposure amounts in the following evaluations were all carried out at the optimum exposure amount.

[0141] 1 is a plan view showing an example of the configuration of a mask pattern. In the figure, in an area 100 of the photomask, an area that transmits exposure light is indicated by reference numeral 10 (transmitting area 10), and an area that does not transmit exposure light is indicated by reference numeral 1 (light-shielding area 1). In the figure, the light-shielding area 1 is indicated by diagonal lines.

[0142] The transparent region 10 has a predetermined width and extends in the x direction, and a plurality of such transparent regions 10 are arranged at predetermined intervals in the width direction (y direction). In this example, the unexposed portions of the photosensitive resin layer are removed through the development process described above, and therefore, based on the mask pattern of Figure 1, it is theoretically expected that a resist pattern having an L / S ratio corresponding to the width of the transparent region 10 (L: line) and the width of the light-shielding region 1 (S: space) will be formed.

[0143] <Shortest Development Time> The evaluation substrate after the lamination step was subjected to the development step described above, and the shortest time required for the photosensitive resin layer to completely dissolve was determined, and this time was adopted as the shortest development time.

[0144] <Developability> The developability was evaluated based on the following criteria. The shorter the shortest development time, the better the developability was considered to be. In this example, a shortest development time of 23 seconds or less, i.e., an evaluation rank of C or higher, was considered to be acceptable. (Criteria) A: The shortest development time is 17 seconds or less. B: The shortest development time is more than 17 seconds and 20 seconds or less. C: The shortest development time is more than 20 seconds and 23 seconds or less. D: The shortest development time is more than 23 seconds.

[0145] <Adhesion> Evaluation was carried out using a photomask having a mask pattern (see FIG. 2) with an L / S of x / 3x (x = 1 to 10 (varying in 0.5 μm intervals)) (unit: μm). That is, the evaluation substrate obtained through the above-mentioned surface preparation and lamination processes was exposed to light at an optimum exposure dose through the photomask. Thereafter, a resist pattern was formed through the above-mentioned heating process and development process.

[0146] 2 is a plan view showing an example of the configuration of a mask pattern. In the figure, a region 100A of the photomask is shown to have a transmissive region 10 and a light-shielding region 1. In region 100A shown in FIG. 2, the value of L / S is different from that of region 100 shown in FIG.

[0147] The formed resist pattern was observed under an optical microscope at 100x magnification. In the observed image, lines (exposed areas) formed without meandering or chipping were detected, and adhesion was evaluated based on the minimum line width according to the following criteria. The smaller the minimum line width, the better the adhesion was considered to be. In this example, a minimum line width of 7.5 μm or less, i.e., an evaluation rank of C or higher, was considered to be acceptable. (Criteria) A: The minimum line width is 5.5 μm or less. B: The minimum line width is greater than 5.5 μm and less than 6.5 μm. C: The minimum line width is greater than 6.5 μm and less than 7.5 μm. D: The minimum line width is greater than 7.5 μm.

[0148] <Resolution> Evaluation was carried out using a photomask having a mask pattern (see FIG. 3) with an L / S ratio of 3x / x (x = 1 to 10 (varying in 0.5 μm intervals)) (unit: μm). That is, the evaluation substrate obtained through the above-mentioned surface preparation and lamination processes was exposed to light at an optimum exposure dose through the photomask. Thereafter, a resist pattern was formed through the above-mentioned heating process and development process.

[0149] 3 is a plan view showing an example of the configuration of a mask pattern. In the figure, a transmissive region 10 and a light-shielding region 1 are shown in region 100B of the photomask. The light-shielding region 1 has a predetermined width and extends in the x direction, and a plurality of such light-shielding regions 1 are arranged in the width direction (y direction) at predetermined intervals. Based on the mask pattern of FIG. 3, it is theoretically expected that a resist pattern having an L / S corresponding to the width of the transmissive region 10 (L: line) and the width of the light-shielding region 1 (S: space) will be formed, similar to the case based on the mask pattern of FIG. 1.

[0150] The formed resist pattern was observed under an optical microscope at 100x magnification. In the observed image, lines formed without meandering or chipping (exposed portions) were detected, and the resolution was evaluated based on the width between those lines (space width) according to the following criteria. The smaller the space width, the better the resolution was considered to be. In this example, a space width of 7.5 μm or less, i.e., an evaluation rank of C or higher, was considered to be acceptable. (Criteria) A: The space width is 5.5 μm or less. B: The space width is greater than 5.5 μm and less than 6.5 μm. C: The space width is greater than 6.5 μm and less than 7.5 μm. D: The space width is greater than 7.5 μm.

[0151] <Flexibility> A flexible substrate (NIKKAFLEX F-30VC1 25RC11(H) manufactured by Nikkan Industries) cut to a size of 200 mm x 250 mm was prepared. Then, after the lamination process described above, a photosensitive resin layer was formed on the substrate. Next, exposure was performed at the optimum exposure dose to a size of 1 inch wide and 250 mm long. Furthermore, after the heating process described above, development was performed according to the development process described above for a time twice the shortest development time, and washing with water was performed. Thereafter, the substrate was cut to a width of 1.2 inches so that the 1-inch-wide cured photosensitive resin layer was located in the center in the width direction, and a sample was produced thereby.

[0152] The prepared samples were subjected to a mandrel test (cylindrical mandrel method; a bending resistance test conforming to JIS K5600-5-1-1999). The diameter of the smallest mandrel (minimum mandrel diameter) at which no cracks and / or peeling from the substrate were observed in the photosensitive resin layer on the sample was then determined, and flexibility was evaluated based on this diameter in accordance with the following criteria. The smaller this value, the higher the flexibility. (Flexibility) A: The minimum mandrel diameter is 8 mm or less. B: The minimum mandrel diameter is greater than 8 mm and less than or equal to 10 mm. C: The minimum mandrel diameter is greater than 10 mm and less than or equal to 13 mm. D: The minimum mandrel diameter is greater than 13 mm.

[0153] In the table below, "the proportion of aromatic rings in component (A)" corresponds to "the content of structural units derived from compounds having an aromatic ring in component (A)", "the mass ratio of component (A) / component (B)" corresponds to "the mass ratio in the photosensitive resin composition {the total content of component (A) / the total content of component (B)}", "the content of component (b1)" corresponds to "the content of component (b1) based on the total amount of component (B)", "the content of compounds which are component (b1) and have a Bis-A structure" corresponds to "the content of compounds which are component (b1) and have a bisphenol A structure based on the total amount of component (B)", and the average number of repeating units (ethylene oxide and / or propylene oxide) in component (B) corresponds to the number of repeating units in one molecule, calculated by number averaging. Furthermore, the "concentration of ethylenically unsaturated bonds" in the claims corresponds to the "concentration of double bonds (mol / g)" in each component in the table below, i.e., the concentration of double bonds (mol / g) calculated based on the number-average number of repeating units in each component (B).

[0154]

[0155]

[0156]

[0157]

[0158] As can be seen from the table, in the examples, good results were confirmed in the evaluations of <adhesion>, <resolution>, and <developability>.

[0159] According to the present invention, a photosensitive resin laminate having good adhesion, resolution, and developability can be obtained. Such a photosensitive resin laminate can be widely used for forming resist patterns on printed wiring boards and the like.

[0160] 1: Light-shielding area 10: Transmitting area 100, 100A, 100B: Areas in the photomask L: Line S: Space

Claims

1. A photosensitive resin laminate comprising a support film and a photosensitive resin layer containing a photosensitive resin composition, wherein the photosensitive resin composition contains the following components: (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a photopolymerization initiator, and the component (A) contains the following components: (A-1) a copolymer containing a structural unit derived from a hydroxyalkyl (meth)acrylate and having a weight-average molecular weight of 25,000 or less, and the content of the structural unit derived from a compound having an aromatic ring in the component (A) is 50 mass% or more based on the total mass of all monomer components.

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

3. The photosensitive resin laminate according to claim 1, wherein the component (B) comprises the following component: (b1) a compound having an ethylenically unsaturated bond concentration of 0.0020 mol / g or more and having two ethylenically unsaturated bonds in one molecule.

4. The photosensitive resin laminate according to claim 3, wherein the concentration of the ethylenically unsaturated bonds in the component (b1) is 0.0024 mol / g or more.

5. The photosensitive resin laminate according to claim 3, wherein the concentration of the ethylenically unsaturated bonds in the component (b1) is 0.0040 mol / g or more.

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 the component (b1) is 75 mass % or more based on the total amount of the component (B).

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

9. The component (B) contains, as the component (b1), a compound represented by the following general formula (III): (In the formula, R ２ is a methyl group or a hydrogen atom, and X ２ O is an oxyethylene group, and m3+m4 is an integer of 2 to 10.

10. The photosensitive resin laminate according to claim 1 or 2, wherein the weight average molecular weight of the copolymer (A-1) is 10,000 to 21,000.

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

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

13. A photosensitive resin laminate according to claim 1 or 2, wherein the mass ratio in the photosensitive resin composition {content of the entire component (A) / content of the entire component (B)} is 1.30 or more.

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

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

16. The photosensitive resin laminate according to claim 1 or 2, further comprising a protective film on the side of the photosensitive resin layer opposite the support.

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

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

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

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

21. A method for forming a wiring board, comprising: a step of forming a resist pattern on a substrate using the photosensitive resin laminate according to any one of claims 1 to 9; a step of forming a conductor pattern by etching or plating the substrate on which the resist pattern has been formed; and a step of peeling off the resist pattern from the substrate.

Images