Photosensitive resin composition

Abstract

A photosensitive resin composition comprising an alkali-soluble polymer, a compound having an olefinic double bond, and a photopolymerization initiator; wherein a photosensitive resin layer formed from the photosensitive resin composition is laminated to a thickness of 25 μm on a copper-clad laminate laminated with an 18 μm thick copper foil; and wherein the composition is subjected to light irradiation and development in a pattern having a line / space ratio of 50 μm / 30 μm to form a cured resist pattern. A copper etching treatment is performed at 50°C for 55 seconds, and the bottom width of the copper line pattern obtained by removing the cured resist pattern is 38 μm or greater.

Description

[0001] The present application is a divisional application of an application filed on September 7, 2016, with application number 201680052525.7 and the invention name being photosensitive resin composition. Technical Field

[0002] <Technical Field According to the First Embodiment of the Present Invention>

[0003] A first embodiment of the present invention relates to a photosensitive resin composition.

[0004] <Technical Field According to Second Embodiment of the Present Invention>

[0005] A second embodiment of the present invention relates to a photosensitive resin composition and the like.

[0006] <Technical Field According to the Third Embodiment of the Present Invention>

[0007] A third embodiment of the present invention relates to a photosensitive resin composition and the like.

[0008] <Technical Field According to Fourth Embodiment of the Present Invention>

[0009] A fourth embodiment of the present invention relates to a photosensitive resin composition. Background Art

[0010] <Background Art According to the First Embodiment of the Present Invention>

[0011] Printed circuit boards are typically manufactured using photolithography. Photolithography involves forming a layer of a photosensitive resin composition on a substrate, exposing the coating to a pattern and developing it to form a resist pattern. This is followed by etching or plating to form a conductor pattern. The resist pattern is then removed from the substrate to form the desired wiring pattern.

[0012] In this photolithography method, when forming a photosensitive resin composition layer on a substrate, there are known methods such as: a method of removing the solvent after applying a composition solution; a method of laminating a photosensitive element or even a dry film resist formed by laminating a support and a photosensitive resin composition layer on a substrate, and then peeling off the aforementioned support.

[0013] Photosensitive elements are often used in the production of printed wiring boards. There are many known methods for forming wiring patterns using such photosensitive elements and photosensitive resin compositions suitable therefor.

[0014] For example, Patent Document 1 discloses a method for easily forming a copper wiring pattern having a good cross-sectional shape, and a photosensitive resin composition used in the method;

[0015] Patent Document 2 discloses a photosensitive resin composition containing a specific addition-polymerizable monomer having an ethylenic double bond.

[0016] However, in recent years, due to the increasing density of printed circuit boards, substrates have become increasingly multilayered. In multilayer substrates, through-holes are provided to provide electrical connections between stacked substrates. When photolithography is used to form wiring patterns on substrates with through-holes used in multilayer substrates, the resist film (hole-capping film) formed over the through-holes is required to be resistant to damage by spray pressure during development, water washing, and the like (resistance to cracking of the hole-capping film, or even hole-capping properties).

[0017] In this regard, Patent Document 3 discloses a photosensitive resin composition containing a binder polymer having a small dispersion (Mw / Mn), a photopolymerizable compound, and an acridine compound, and states that a resist film having excellent hole-blocking properties can be formed using this composition.

[0018] <Background Art According to the Second Embodiment of the Present Invention>

[0019] Printed circuit boards are typically manufactured using photolithography. Photolithography involves forming a coating film comprising a layer formed from a photosensitive resin composition on a substrate, exposing the coating film to a pattern and developing it to form a resist pattern. This is followed by etching or plating to form a conductor pattern. The resist pattern on the substrate is then removed, thereby forming the desired wiring pattern on the substrate.

[0020] In photolithography, when forming a photosensitive resin layer on a substrate, there are known methods such as: a method of removing the solvent after applying a composition solution; a method of laminating a photosensitive element formed by laminating a support and a photosensitive resin layer, or even a dry film resist, on a substrate, and then peeling off the support.

[0021] Photosensitive elements are often used in the production of printed wiring boards. There are many known methods for forming wiring patterns using such photosensitive elements and photosensitive resin compositions suitable therefor.

[0022] For example, Patent Document 1 discloses a method for easily forming a copper wiring pattern having a good cross-sectional shape and a photosensitive resin composition used in the method, and Patent Document 4 discloses a photosensitive resin composition containing a specific addition-polymerizable monomer having an ethylenic double bond.

[0023] <Background Art According to the Third Embodiment of the Present Invention>

[0024] Printed circuit boards have traditionally been manufactured using photolithography. In photolithography, a pattern of a photosensitive resin composition layer stacked on a substrate is first exposed. The exposed portion of the photosensitive resin composition undergoes polymerization and solidification (in the case of a negative type) or becomes soluble in a developer (in the case of a positive type). Next, the unexposed portion (in the case of a negative type) or the exposed portion (in the case of a positive type) is removed with a developer to form a resist pattern on the substrate. Furthermore, after etching or plating to form a conductor pattern, the resist pattern is peeled off from the substrate. Through these steps, a conductor pattern is formed on the substrate.

[0025] Photolithography generally involves applying a solution of a photosensitive resin composition onto a substrate and drying it, or laminating a photosensitive resin composition layer of a dry film resist (a photosensitive resin laminate formed by laminating a photosensitive resin composition layer on a support) onto a substrate. The latter method is often used in the manufacture of printed circuit boards.

[0026] With the recent miniaturization of wiring pitches on printed circuit boards, dry film resists are required to have various properties. While the thickness of dry film resists tends to decrease with miniaturization of wiring pitches, they still require strong hole-covering properties to protect the through-holes in the substrate.

[0027] In addition, when developing the resist pattern, the resist components are eluted between the patterns due to the water remaining between the patterns, resulting in water residual short circuit failure. In order to reduce this water residual short circuit failure, it is necessary to improve the hydrophobicity of the cured resist.

[0028] In order to improve the properties of resists, various photosensitive resin compositions have been proposed (Patent Documents 5 and 6).

[0029] <Background Art According to the Fourth Embodiment of the Present Invention>

[0030] Printed circuit boards are typically manufactured using photolithography. Photolithography involves forming a layer of a photosensitive resin composition on a substrate, exposing and developing the coating to form a resist pattern, then etching or plating to form a conductor pattern. The resist pattern is then removed from the substrate to form the desired wiring pattern.

[0031] In photolithography, when forming a photosensitive resin layer on a substrate, there are known methods such as a method of applying a composition solution and then removing the solvent; a method of laminating a photosensitive element composed of a support and a photosensitive resin layer, or even a dry film resist, on a substrate and then peeling off the support.

[0032] Photosensitive elements are often used in the manufacture of printed circuit boards. Methods for forming wiring patterns using such photosensitive elements, and suitable photosensitive resin compositions for such methods, are known (Patent Documents 1 and 2). Patent Document 1 describes a conventional method for forming a copper wiring pattern having a good cross-sectional shape, and a photosensitive resin composition used therefor. Patent Document 2 describes a photosensitive resin composition containing a specific addition-polymerizable monomer having an ethylenically unsaturated bond.

[0033] With the recent miniaturization of wiring spacing in printed circuit boards, dry film resists are required to have properties such as resolution. For example, various photosensitive resin compositions have been proposed to improve the properties of resist patterns (Patent Documents 5 and 6).

[0034] Prior art literature

[0035] Patent Literature

[0036] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-233769

[0037] Patent Document 2: International Publication No. 2009 / 022724

[0038] Patent Document 3: Japanese Patent Application Laid-Open No. 2013-109321

[0039] Patent Document 4: Japanese Patent Application Laid-Open No. 2015-60120

[0040] Patent Document 5: International Publication No. 2015 / 098870

[0041] Patent Document 6: Japanese Patent Application Laid-Open No. 2014-048340 Summary of the Invention

[0042] Problems to be solved by the invention

[0043] <Problems to be Solved by the First Embodiment of the Present Invention>

[0044] In recent years, the manufacture of circuit boards has generally been carried out by using an assembly line in which a substrate is transported in a fixed direction while being processed in sequence. Here, when forming a conductor pattern such as a line / space pattern on a substrate, there are cases where the conductor lines are parallel (lines in the MD direction), perpendicular (lines in the TD direction), or skewed relative to the transport direction of the substrate. When a conductor pattern of a line / space pattern is formed by an assembly line using an anti-corrosion material of the prior art, the wiring widths of the lines in the MD direction and the lines in the TD direction are different, resulting in a so-called vertical and horizontal difference in wiring width. In many cases, the lines in the MD direction are more easily corroded by the etching solution than the lines in the TD direction, so there is a tendency for the etching amount to increase and the wiring width to become thinner. In order to form a fine conductor pattern by an assembly line, it is preferable to reduce the wiring width difference between the wiring in the MD direction and the wiring in the TD direction.

[0045] However, in the prior art represented by Patent Documents 1 to 3 mentioned above, no research has been conducted from this viewpoint, and a resist material for reducing the vertical and horizontal differences in wiring width is still unknown.

[0046] The first embodiment of the present invention has been made in view of the above-mentioned current situation. Therefore, an object of the first embodiment of the present invention is to provide a resist material that suppresses vertical and horizontal differences in wiring width when forming a fine conductor pattern in an in-line manner.

[0047] <Problems to be Solved by the Second Embodiment of the Present Invention>

[0048] In order to form a resist pattern using a photosensitive resin composition, a development step is required. During this development step, the composition in the exposed areas is dissolved and removed in the case of a positive-type composition, and in the case of a negative-type composition, the composition in the exposed areas is dissolved and removed, thereby forming a resist pattern. During this development step, the composition in the unwanted areas is not completely "dissolved" in the developer; rather, at least a portion of it remains insoluble and dispersed in the developer, thereby being removed from the substrate. Therefore, each time the development step is repeated, the amount of unwanted substances in the developer increases, and eventually, the insoluble components with poor dispersibility sometimes form aggregates. These aggregates adhere to the substrate to be developed later and remain, sometimes causing short circuit failures, etc.

[0049] Therefore, from the viewpoint of improving the product yield in the development step and further reducing the production cost of printed wiring boards, it is strongly desired that the photosensitive resin composition used has good dispersibility in a developer.

[0050] In recent years, demand for miniaturization and refinement of printed circuit boards has been increasing. Consequently, the photosensitive resin compositions used in the formation of these printed circuit boards are also required to be capable of forming fine patterns. The minimum size of a pattern formed on a substrate depends on the exposure wavelength. Therefore, theoretically, forming a fine pattern by exposure using a photosensitive polymerization initiator appropriate for the exposure wavelength is not particularly difficult. However, fine patterns formed by exposure, for example, with a size of tens of microns or less, sometimes peel off from the substrate during subsequent steps such as development, resulting in limitations in the miniaturization of printed circuit boards.

[0051] Therefore, in order to form a fine printed wiring board, a photosensitive resin composition having high adhesion to a fine pattern is required.

[0052] However, the photosensitive resin compositions described in Patent Documents 1 and 4 cannot meet today's stringent requirements in terms of both development dispersibility and fine pattern adhesion, and there is still room for improvement in this field.

[0053] The second embodiment of the present invention has been made in view of such circumstances.

[0054] Therefore, an object of the second embodiment of the present invention is to provide a novel photosensitive material having high-level performance such as resolution generally required of photosensitive materials and excellent development dispersibility and adhesion to fine patterns.

[0055] <Problems to be Solved by the Third Embodiment of the Present Invention>

[0056] Patent Document 5 studies a photosensitive resin composition comprising a binder polymer having a (meth)acrylic acid structural unit, a styrene or α-methylstyrene structural unit, and a hydroxyalkyl (meth)acrylate structural unit having a hydroxyalkyl group having 1 to 12 carbon atoms, and a bisphenol-type di(meth)acrylate monomer having 1 to 20 ethyleneoxy structural units and 0 to 7 propyleneoxy structural units, from the viewpoints of the developability of the photosensitive resin composition and the resolution, adhesion, and bendability of the resist pattern.

[0057] In Patent Document 6, from the perspective of the spacing width and hole covering properties of the positive resist pattern, the content of the structural unit of styrene or a styrene derivative in the alkali-soluble polymer is proposed to be 30% by mass or more, and the weight average molecular weight of the addition polymerizable monomer is proposed to be 1100 or more.

[0058] Both Patent Documents 5 and 6 focus on photosensitive resin compositions comprising a polymer having a structural unit of styrene at a specific ratio and a specific monomer. However, the photosensitive resin compositions described in Patent Documents 5 and 6 still have room for improvement from the perspective of achieving both the hole-covering properties of the resist pattern and the ability to suppress short-circuit failures caused by residual water.

[0059] Therefore, the problem to be solved by the third embodiment of the present invention is to provide a photosensitive resin composition capable of achieving both the hole-covering property of a resist pattern and the ability to suppress a short-circuit failure caused by residual water.

[0060] <Problems to be Solved by the Fourth Embodiment of the Present Invention>

[0061] In recent years, circuit board manufacturing has typically been conducted using production lines where substrates are processed sequentially while being transported in a fixed direction. In these cases, the developer or etchant applied to the substrates is sprayed. In photolithography-based resist pattern formation, it is crucial to minimize variations in the resist line width after development. However, spray-developed resist pattern formation is prone to within-surface variations in the developer when development times are short, sometimes leading to the aforementioned issues. Therefore, extended development times are required.

[0062] Here, the development time refers to the time the substrate remains in the developer tank for development, and is determined, for example, as twice the minimum development time. The minimum development time is the minimum time required to completely dissolve and remove the unexposed portions of the photosensitive resin layer, and varies depending on factors such as the developer concentration and temperature, the spray direction and amount, the pressure, and the vibration frequency.

[0063] Here, it is believed that the dissolution reaction of the resist based on development is roughly controlled by the diffusion of the developer and occurs. Therefore, from the viewpoint of promoting development, it is necessary to actively supply the developer to the substrate based on spraying or the like. This supply takes some time, so it can be believed that when the development time is short, the supply of the developer cannot fully spread over the entire substrate, and the deviation of the resist line width becomes significantly larger. On the other hand, it can be believed that when the development time is long, the supply of the developer on the substrate becomes uniform, so the deviation of the line width also becomes smaller. Therefore, it can be believed that using a photosensitive resin composition with a slower minimum development time itself is effective from the viewpoint of suppressing the deviation of the line width.

[0064] Patent Document 5 studies a photosensitive resin composition comprising a binder polymer having a (meth)acrylic acid structural unit, a styrene or α-methylstyrene structural unit, and a hydroxyalkyl (meth)acrylate structural unit having a hydroxyalkyl group having 1 to 12 carbon atoms, and a bisphenol-type di(meth)acrylate monomer having 1 to 20 ethyleneoxy structural units and 0 to 7 propyleneoxy structural units, from the viewpoints of the developability of the photosensitive resin composition and the resolution, adhesion, and bendability of the resist pattern.

[0065] In Patent Document 6, from the perspective of the spacing width and pore-covering properties of the positive resist pattern, the content of the structural unit of styrene or a styrene derivative in the alkali-soluble polymer is proposed to be 30% by mass or more, and the weight average molecular weight of the addition polymerizable monomer is proposed to be 1100 or more.

[0066] Both Patent Documents 5 and 6 focus on photosensitive resin compositions comprising a polymer having a structural unit of styrene at a specific ratio and a specific monomer. However, the photosensitive resin compositions described in Patent Documents 5 and 6 still have room for improvement from the perspective of achieving both good resolution of the resist pattern and an extension of the minimum development time.

[0067] Therefore, the problem to be solved by the fourth embodiment of the present invention is to provide a photosensitive resin composition capable of achieving both good resolution of a resist pattern and extended minimum development time.

[0068] Solutions for solving problems

[0069] <Means for solving the first problem>

[0070] The present inventors have found that the above-mentioned object can be achieved by the following technical means, and have completed the first embodiment of the present invention. The first embodiment of the present invention is as follows. [1]

[0072] A photosensitive resin composition, characterized in that it contains the following components (A) to (C),

[0073] (A) Ingredients: Alkali-soluble polymer,

[0074] (B) Component: a compound having an ethylenic double bond, and

[0075] Component (C): Photopolymerization initiator

[0076] A photosensitive resin layer formed from the above-mentioned photosensitive resin composition was laminated with a thickness of 25 μm on a copper-clad laminate laminated with a copper foil having a thickness of 18 μm. A cured resist pattern was formed by light irradiation and development treatment in a pattern having a line / space of 50 μm / 30 μm. After a copper etching treatment was performed at 50°C for 55 seconds, the bottom width of the copper line pattern obtained by removing the above-mentioned cured resist pattern was 38 μm or more. [2]

[0078] The photosensitive resin composition according to [1], wherein the component (A) is a copolymer having a (meth)acrylic acid unit content of 10% by mass or more and 24% by mass or less. [3]

[0080] The photosensitive resin composition according to [1] or [2], wherein the component (A) is a copolymer having a styrene unit content of 32% by mass or more and 60% by mass or less. [4]

[0082] The photosensitive resin composition according to any one of [1] to [3], wherein the component (C) contains an acridine compound. [5]

[0084] The photosensitive resin composition according to any one of [1] to [4], wherein the component (B) contains a pentaerythritol compound. [6]

[0086] The photosensitive resin composition according to any one of [1] to [5], wherein the component (B) contains a trimethylolpropane compound. [7]

[0088] The photosensitive resin composition according to any one of [1] to [6], wherein the component (B) contains a bisphenol A compound. [8]

[0090] A photosensitive resin composition comprising the following components (A) to (C),

[0091] (A) Ingredients: Alkali-soluble polymer,

[0092] (B) Component: a compound having an ethylenic double bond, and

[0093] Component (C): Photopolymerization initiator

[0094] The component (A) comprises a copolymer containing 10% by mass or more and 24% by mass or less of (meth)acrylic acid units and 32% by mass or more of styrene units.

[0095] The component (C) contains an acridine compound. [9]

[0097] The photosensitive resin composition according to [8], wherein the component (A) comprises a copolymer having a (meth)acrylic acid unit content of 10% by mass to 24% by mass and a styrene unit content of 32% by mass to 60% by mass.

[10]

[0099] The photosensitive resin composition according to [8] or [9], wherein the component (B) contains a pentaerythritol compound.

[11]

[0101] The photosensitive resin composition according to any one of [8] to

[10] , wherein the component (B) contains a trimethylolpropane compound.

[12]

[0103] The photosensitive resin composition according to any one of [8] to

[11] , wherein the component (B) contains a bisphenol A compound.

[13]

[0105] A photosensitive element comprising a photosensitive resin layer formed from the photosensitive resin composition according to any one of [1] to

[12] and laminated on a support.

[14]

[0107] A method for forming a resist pattern, comprising:

[0108] a lamination step of laminating the photosensitive resin layer of the photosensitive element described in

[13] on a conductive substrate,

[0109] an exposure step of exposing the laminated photosensitive resin composition layer to light, and

[0110] A development step in which the unexposed portion after the exposure is removed using a developer.

[15]

[0112] The method for forming a resist pattern according to

[14] , wherein the lamination step is a step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate with a wetting agent interposed therebetween.

[16]

[0114] A method for manufacturing a circuit board, comprising:

[0115] a lamination step of laminating the photosensitive resin composition layer of the photosensitive element described in

[13] on a conductive substrate,

[0116] an exposure step of exposing the laminated photosensitive resin composition layer to light,

[0117] A developing step of removing the unexposed portion after exposure with a developer,

[0118] A conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed by the development, and

[0119] A peeling step of peeling off the resist pattern.

[17]

[0121] The method for manufacturing a circuit board according to

[16] , wherein the lamination step is a step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate with a wetting agent interposed therebetween.

[0122] <Means for Solving the Second Problem>

[0123] The present inventors have found that the above-mentioned object can be achieved by the following technical means, and have completed the second embodiment of the present invention. The second embodiment of the present invention is as follows. [1]

[0125] A photosensitive resin composition, characterized in that it contains the following components (A) to (C),

[0126] (A) Component: Alkali-soluble polymer with an acid equivalent of 100 to 600,

[0127] (B) Component: a compound having an ethylenic double bond, and

[0128] Component (C): Photopolymerization initiator

[0129] The component (A) contains a copolymer containing 50% by mass or more of styrene units,

[0130] The component (B) contains a compound represented by the following general formula (I):

[0131]

[0132] {In the formula, R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n1, n2, and n3 are independently integers of 0 to 30, wherein n1+n2+n3≥6 is satisfied.}

[0133] The content of the compound represented by the general formula (I) is 5% by mass or more based on the solid content of the photosensitive resin composition, and the component (C) contains an acridine compound. [2]

[0135] The photosensitive resin composition according to [1], wherein n1, n2, and n3 in the general formula (I) satisfy 20≥n1+n2+n3>9. [3]

[0137] The photosensitive resin composition according to [1] or [2], wherein all R in the general formula (I) are hydrogen atoms. [4]

[0139] The photosensitive resin composition according to any one of [1] to [3], wherein the component (B) further contains a pentaerythritol-modified monomer. [5]

[0141] A photosensitive element comprising a photosensitive resin layer formed from the photosensitive resin composition according to any one of [1] to [4] and laminated on a support. [6]

[0143] A method for forming a resist pattern, comprising:

[0144] a lamination step of laminating the photosensitive resin layer of the photosensitive element described in [5] on a conductive substrate, an exposure step of exposing the laminated photosensitive resin layer, and

[0145] A development step in which the unexposed portion after the exposure is removed using a developer. [7]

[0147] A method for manufacturing a circuit board, comprising:

[0148] a lamination step of laminating the photosensitive resin layer of the photosensitive element described in [5] on a conductive substrate, an exposure step of exposing the laminated photosensitive resin layer,

[0149] A developing step of removing the unexposed portion after exposure with a developer,

[0150] A conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed by the development, and

[0151] A peeling step of peeling off the resist pattern.

[0152] <Means for Solving the Third Problem>

[0153] The present inventors have discovered that the above-mentioned problems can be solved by the following technical means: A third embodiment of the present invention is as follows. [1]

[0155] A photosensitive resin composition, characterized by comprising:

[0156] (A) Alkali-soluble polymer;

[0157] (B) an ethylenically unsaturated bond-containing compound; and

[0158] (C) a photopolymerization initiator;

[0159] The alkali-soluble polymer (A) comprises 10% to 24% by mass of (meth)acrylic acid structural units and 35% to 90% by mass of styrene structural units based on the total mass of monomers constituting the alkali-soluble polymer (A), and

[0160] The weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is 1200 or more. [2]

[0162] The photosensitive resin composition according to [1], wherein the weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is 1300 or more. [3]

[0164] The photosensitive resin composition according to [1] or [2], wherein 40% by mass or more of the (B) ethylenically unsaturated bond-containing compound is an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the following general formula (II),

[0165]

[0166] {In the formula, R3 and R4 independently represent a hydrogen atom or a methyl group, A is C2H4, B is C3H6, n1, n2, n3 and n4 are integers satisfying the relationship n1+n2+n3+n4=2 to 50, and the arrangement of the repeating units of -(AO)- and -(BO)- can be random or block. In the case of block, any one of -(AO)- and -(BO)- can be on the biphenyl side}. [4]

[0168] The photosensitive resin composition according to [3], wherein n1, n2, n3 and n4 in the general formula (II) satisfy the relationship of n1+n2+n3+n4=30 to 50. [5]

[0170] The photosensitive resin composition according to [3], wherein n1, n2, n3 and n4 in the general formula (II) satisfy the relationship of n1+n2+n3+n4=2 to 10. [6]

[0172] The photosensitive resin composition according to [1] or [2], wherein the (B) ethylenically unsaturated bond-containing compound comprises a tri(meth)acrylate compound represented by the following general formula (III):

[0173]

[0174] {wherein, R5, R6 and R7 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3 and m4 independently represent integers of 0 to 40, m2+m3+m4 is 1 to 40, and when m2+m3+m4 is 2 or more, multiple Xs may be the same or different from each other}. [7]

[0176] The photosensitive resin composition according to [1] or [2], wherein the (B) ethylenically unsaturated bond-containing compound comprises a urethane di(meth)acrylate compound represented by the following general formula (IV):

[0177]

[0178] {wherein, R8 and R9 independently represent a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 6 carbon atoms, Z represents a divalent organic group, s and t independently represent integers of 0 to 40, and s+t≥1}. [8]

[0180] The photosensitive resin composition according to any one of [1] to [7], wherein the (A) alkali-soluble polymer further includes a structural unit of butyl (meth)acrylate. [9]

[0182] The photosensitive resin composition according to any one of [1] to [8], which is used for direct imagewise exposure.

[10]

[0184] A method for forming a resist pattern, comprising:

[0185] a lamination step of laminating a photosensitive resin layer formed from the photosensitive resin composition according to any one of [1] to [9] on a support;

[0186] an exposure step of exposing the photosensitive resin layer to light; and

[0187] A developing step is performed to develop the exposed photosensitive resin layer.

[11]

[0189] A method for manufacturing a circuit board, comprising:

[0190] a lamination step of laminating a photosensitive resin layer formed from the photosensitive resin composition according to any one of [1] to [9] on a substrate;

[0191] an exposure step of exposing the photosensitive resin layer to light;

[0192] a developing step of developing the exposed photosensitive resin layer to obtain a substrate having a resist pattern formed thereon;

[0193] a conductor pattern forming step of etching or plating the substrate having the resist pattern formed thereon; and

[0194] A peeling step of peeling off the resist pattern.

[0195] <Means for Solving the Fourth Problem>

[0196] The present inventors have found that the above-mentioned object can be achieved by the following technical means, and have completed the fourth embodiment of the present invention. The fourth embodiment of the present invention is as follows. [1]

[0198] A photosensitive resin composition comprising:

[0199] (A) Alkali-soluble polymer;

[0200] (B) an ethylenically unsaturated bond-containing compound; and

[0201] (C) a photopolymerization initiator;

[0202] The alkali-soluble polymer (A) comprises a first copolymer having an acid monomer unit content of less than 25% by mass and an aromatic monomer unit content of 30% by mass or more, and

[0203] The weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is 900 or less. [2]

[0205] The photosensitive resin composition according to [1], wherein the (C) photopolymerization initiator contains an acridine compound. [3]

[0207] The photosensitive resin composition according to [1] or [2], wherein the alkali-soluble polymer (A) comprises a second copolymer having an aromatic monomer unit content of 45% by mass to 90% by mass. [4]

[0209] The photosensitive resin composition according to any one of [1] to [3], wherein the (B) ethylenically unsaturated bond-containing compound comprises a tri(meth)acrylate compound represented by the following general formula (III):

[0210]

[0211] {wherein, R5, R6 and R7 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3 and m4 independently represent integers of 0 to 40, m2+m3+m4 is 0 to 40, and when m2+m3+m4 is 2 or more, multiple Xs may be the same or different from each other}. [5]

[0213] The photosensitive resin composition according to any one of [1] to [4], wherein the (B) ethylenically unsaturated bond-containing compound comprises an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the following general formula (II):

[0214]

[0215] {In the formula, R3 and R4 independently represent a hydrogen atom or a methyl group, A is C2H4, B is C3H6, n1, n2, n3 and n4 are integers satisfying the relationship n1+n2+n3+n4=2 to 50, and the arrangement of the repeating units of -(AO)- and -(BO)- can be random or block. In the case of block, any one of -(AO)- and -(BO)- can be on the biphenyl side}. [6]

[0217] The photosensitive resin composition according to any one of [1] to [5], further comprising a compound represented by the following general formula (V) as a hindered phenol:

[0218]

[0219] {where R 51 represents an optionally substituted straight-chain alkyl group, a branched-chain alkyl group, an aryl group, a cyclohexyl group, a straight-chain alkyl group sandwiched by a divalent linking group, a branched-chain alkyl group sandwiched by a divalent linking group, a cyclohexyl group sandwiched by a divalent linking group, or an aryl group sandwiched by a divalent linking group, and R 52 、R 53 and R 54 Each independently represents hydrogen, or an optionally substituted straight-chain alkyl group, a branched-chain alkyl group, an aryl group, a cyclohexyl group, a straight-chain alkyl group sandwiched by a divalent linking group, a branched-chain alkyl group sandwiched by a divalent linking group, a cyclohexyl group sandwiched by a divalent linking group, or an aryl group sandwiched by a divalent linking group. [7]

[0221] The photosensitive resin composition according to any one of [1] to [6], which is used for direct imagewise exposure. [8]

[0223] A photosensitive element comprising a photosensitive resin layer formed from the photosensitive resin composition according to any one of [1] to [7] and laminated on a support. [9]

[0225] A method for forming a resist pattern, comprising:

[0226] a lamination step of laminating the photosensitive resin layer of the photosensitive element described in [8] on a conductive substrate;

[0227] an exposure step of exposing the stacked photosensitive resin layer to light; and

[0228] A developing step of developing the exposed photosensitive resin layer.

[10]

[0230] A method for manufacturing a circuit board, comprising:

[0231] a lamination step of laminating the photosensitive resin layer of the photosensitive element described in [8] on a conductive substrate;

[0232] an exposure step of exposing the stacked photosensitive resin layer to light;

[0233] a developing step of developing the exposed photosensitive resin layer to form a resist pattern on the conductive substrate;

[0234] a conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed; and

[0235] A peeling step of peeling off the resist pattern.

[0236] Effects of the Invention

[0237] <Effects of the First Embodiment>

[0238] According to the first embodiment of the present invention, there is provided a resist material that suppresses vertical and horizontal variations in wiring width when forming a fine conductor pattern in-line.

[0239] <Effects of the Second Embodiment>

[0240] According to the second embodiment of the present invention, there is provided a novel photosensitive material having high-level performances generally required of photosensitive materials, such as sensitivity and resolution, and having excellent development dispersibility and adhesion to fine patterns.

[0241] <Effects of the Third Embodiment>

[0242] According to a third embodiment of the present invention, a photosensitive resin composition is provided that can achieve both the hole-covering property of a resist pattern and the ability to suppress a short-circuit failure caused by residual water.

[0243] <Effects of the Fourth Embodiment>

[0244] According to a fourth embodiment of the present invention, there are provided a photosensitive resin composition capable of ensuring good resolution of a resist pattern and extending the minimum development time, and a method for forming a resist pattern or a circuit board using the same. DETAILED DESCRIPTION

[0245] <First embodiment>

[0246] Hereinafter, a mode for implementing the first embodiment of the present invention (hereinafter simply referred to as “this first embodiment”) will be described in detail.

[0247] <Photosensitive resin composition>

[0248] In the first embodiment, the photosensitive resin composition contains the following components (A) to (C).

[0249] (A) Ingredients: Alkali-soluble polymer,

[0250] (B) Component: a compound having an ethylenic double bond, and

[0251] Component (C): photopolymerization initiator.

[0252] [(A) Component: Alkali-soluble polymer]

[0253] The component (A) is not particularly limited as long as it dissolves in the developer described below. It is preferably a copolymer of (meth)acrylic acid and other monomers. The dispersity of the copolymer, represented by the ratio of the weight average molecular weight (described below) to the number average molecular weight of the copolymer, is preferably 1 or more and 6 or less.

[0254] Examples of (meth)acrylic acid include (meth)acrylic acid, pentenoic acid, unsaturated dicarboxylic anhydride, and hydroxystyrene. Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, itaconic anhydride, fumaric acid, and citraconic anhydride. Among these, (meth)acrylic acid is preferred.

[0255] The copolymerization ratio of the (meth)acrylic acid unit in the component (A) is preferably 10% to 24% by mass, more preferably 15% to 23% by mass, relative to the total mass of all monomer units. A content of the (meth)acrylic acid unit within this range is preferred from the viewpoints of suppressing the etching rate during conductor pattern formation (maintaining the bottom width of the conductor line pattern at a constant level or above) and suppressing the vertical and horizontal differences in wiring width.

[0256] Examples of other monomers include unsaturated aromatic compounds (sometimes also referred to as “aromatic monomers”), alkyl (meth)acrylates, aralkyl (meth)acrylates, conjugated diene compounds, polar monomers, and crosslinking monomers.

[0257] Examples of the unsaturated aromatic compound include styrene, α-methylstyrene, and vinylnaphthalene, among which styrene is preferred.

[0258] The term "alkyl (meth)acrylate" is a concept encompassing both chain alkyl esters and cyclic alkyl esters. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate.

[0259] Respectively, as the aralkyl (meth)acrylate, for example, benzyl (meth)acrylate and the like can be cited;

[0260] Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene.

[0261] Examples of polar monomers include:

[0262] Hydroxyl-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and pentenol;

[0263] Amino-containing monomers such as 2-aminoethyl methacrylate;

[0264] (Meth) acrylamide, N-hydroxymethyl (meth) acrylamide and other amide-containing monomers;

[0265] Acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-cyanoethyl acrylate and other cyano group-containing monomers;

[0266] Epoxy-containing monomers such as glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate;

[0267] wait.

[0268] Examples of the crosslinkable monomer include trimethylolpropane triacrylate and divinylbenzene.

[0269] As the component (A), a copolymer of (meth)acrylic acid, styrene and other monomers is particularly preferred.

[0270] The copolymerization ratio of the styrene units in the aforementioned (A) component is preferably 32% by mass or more, more preferably 35% by mass or more, relative to the total mass of all monomeric units. In addition, the copolymerization ratio of the styrene units in the aforementioned (A) component is preferably 60% by mass or less, more preferably 55% by mass or less, relative to the total mass of all monomeric units. When the copolymerization ratio of styrene, which is highly hydrophobic and difficult to be compatible with developer and developer cleaning water, is set to the above range, it is preferred from the viewpoint of suppressing the vertical and horizontal difference in wiring width.

[0271] The weight average molecular weight of the component (A) (when the component (A) comprises a plurality of copolymers, the weight average molecular weight of the entire mixture) is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 15,000 to 100,000. Adjusting the weight average molecular weight of the component (A) within this range is preferred from the viewpoint of adapting the development time during resist pattern formation to the operating conditions of the line used.

[0272] In the first embodiment, the content of component (A) in the photosensitive resin composition is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 40% to 60% by mass, based on the total solid content of the photosensitive resin composition (hereinafter, unless otherwise specified, the same shall apply to each component). This content is preferably 10% by mass or more from the viewpoint of maintaining alkali developability, and is preferably 90% by mass or less from the viewpoint of fully exhibiting the performance of the resist pattern formed by exposure.

[0273] The copolymer containing 10% to 24% by mass of (meth)acrylic acid units and 32% to 60% by mass of styrene units is preferably 8% or more, more preferably 10% or more, and particularly preferably 13.5 / 99.19×100% or more by mass, based on the total solid content of the photosensitive resin composition. The copolymer containing 10% to 24% by mass of (meth)acrylic acid units and 32% to 60% by mass of styrene units may be 50% or less, 40% or less, 30% or less, 27 / 99.19×100% or less, or 20% or less by mass, based on the total solid content of the photosensitive resin composition.

[0274] [Component (B): Compound having an olefinic double bond]

[0275] The component (B) may have one or more ethylenic double bonds, and preferably a compound having two or more ethylenic double bonds is used.

[0276] As the compound (B) having two ethylenic double bonds, for example, a bisphenol A compound, particularly a di(meth)acrylate of a polyalkylene glycol obtained by adding an average of 2 to 15 mol of alkylene oxide to both ends of bisphenol A, is preferably used.

[0277] As the (B) compound having three ethylenic double bonds, for example, a trimethylolpropane compound, particularly a tri(meth)acrylate of a polyalkylene triol obtained by adding an average of 3 to 25 mol of alkylene oxide to trimethylolpropane, is preferably used.

[0278] Furthermore, as the (B) compound having four ethylenic double bonds, for example, a pentaerythritol compound, particularly a tetra(meth)acrylate of a polyol obtained by adding an average of 4 to 35 mol of an alkylene oxide to pentaerythritol, is preferably used.

[0279] Examples of commercially available products thereof include "BPE-500", "A-TMPT-3EO", and "A-9300-1CL" (all manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0280] "ARONIX M-327" and the like (manufactured by Toagosei Co., Ltd.) and the like.

[0281] The content of component (B) in the photosensitive resin composition of the first embodiment is preferably 1% to 70% by mass, more preferably 5% to 60% by mass, and even more preferably 10% to 50% by mass. This content is preferably 1% by mass or more from the viewpoint of suppressing poor curing and delayed development time, while it is preferably 70% by mass or less from the viewpoint of suppressing cold flow and delayed peeling of the cured resist.

[0282] As component (B), a high molecular weight compound having a molecular weight of 1000 or more is preferably used. The molecular weight of the high molecular weight compound is more preferably 1300 or more and 3000 or less. Inclusion of such a high molecular weight compound is preferred from the viewpoint of suppressing the etching rate during conductor pattern formation and suppressing the longitudinal and lateral differences in wiring width.

[0283] The proportion of the high molecular weight compound in the component (B) is preferably 20% by mass or more, more preferably 20 to 50% by mass.

[0284] Here, the DD value is defined as an indicator of the double bond concentration of the component (B). The DD value is the number of double bonds per weight average molecular weight of a monomer, and has a unique value for each monomer.

[0285] When a monomer having a small DD value is used in a photosensitive resin composition, the film after photocuring tends to become flexible.

[0286] When the component (B) is composed of a plurality of types, the weighted average of the DD values ​​and the blending ratios of the individual ethylenically unsaturated bond-containing compounds is regarded as the DD value of the composition.

[0287] From the viewpoint of suppressing the vertical and horizontal differences in wiring width and improving the hole-covering property, the DD value of the composition is preferably in the range of 0.10 to 0.13, and more preferably 0.10 to 0.125.

[0288] [Component (C): Photopolymerization initiator]

[0289] The component (C) generates radicals capable of initiating polymerization of the component (B) upon irradiation with light.

[0290] Examples of the component (C) include aromatic ketone compounds, quinone compounds, benzoin ether compounds, benzoin compounds, benzyl compounds, hexaarylbiimidazole compounds, and acridine compounds.

[0291] Among them, acridine compounds are preferably used from the viewpoint of high resolution and good pore coverage.

[0292] The content of the acridine compound in the photosensitive resin composition of the first embodiment is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0.2% by mass, more preferably 0.3% by mass, and more preferably 0.4% by mass.

[0293] The content of the acridine compound in the photosensitive resin composition of the first embodiment is preferably 2.0% by mass or less, more preferably 1.8% by mass or less, more preferably 1.7% by mass or less, and more preferably 1.6% by mass or less. Within the above range, a resist material can be provided that suppresses vertical and horizontal differences in wiring width, which is preferred.

[0294] Examples of the acridinium compound include acridine, 9-phenylacridine, 1,6-bis(9-acridyl)hexane, 1,7-bis(9-acridyl)heptane, 1,8-bis(9-acridyl)octane, 1,9-bis(9-acridyl)nonane, 1,10-bis(9-acridyl)decane, 1,11-bis(9-acridyl)undecane, and 1,12-bis(9-acridyl)dodecane.

[0295] As the component (C), an acridine compound and a hexaarylbiimidazole compound are preferably used.

[0296] Examples of the hexaarylbiimidazole compound include 2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylimidazolyl dimer, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylimidazolyl dimer, 2,4,5-tris-(o-chlorophenyl)-diphenylimidazolyl dimer, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-imidazolyl dimer, 2,2',5-bis-(2-fluorophenyl)-4, 4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer imidazolyl dimer, 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer , 2,2'-bis-(2,4,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, etc.

[0297] The content of component (C) in the photosensitive resin composition of the first embodiment is preferably 0.1% to 2% by mass, more preferably 0.2% to 1.8% by mass, further preferably 0.3% to 1.7% by mass, and particularly preferably 0.4% to 1.6% by mass. Setting the content of component (C) within this range is preferred from the viewpoint of obtaining good sensitivity and peeling properties.

[0298] From the viewpoint of improving sensitivity and resolution, the component (C) may further contain a sensitizer. Examples of such a sensitizer include N-arylamino acids, organic halogen compounds, and other sensitizers.

[0299] Respectively, examples of the above-mentioned N-aryl amino acids include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine;

[0300] Examples of the organic halogen compound include amyl bromide, isopentyl bromide, isobutylene bromide, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and chlorinated triazine compounds.

[0301] Examples of the other sensitizers include quinone compounds such as 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone;

[0302] Aromatic ketone compounds such as benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4,4'-bis(diethylamino)benzophenone;

[0303] Benzoin ether compounds such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, and ethyl benzoin;

[0304] Benzil dimethyl ketal, benzil diethyl ketal, 1-phenyl-1,2-propanedione-2-O-benzoyl oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime and other oxime ester compounds;

[0305] wait.

[0306] The content of the sensitizer in the first embodiment is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably 0.1 to 2% by mass, from the viewpoint of the sensitivity of the composition and the releasability of the cured resist film.

[0307] It should be noted that in the photosensitive resin composition of the first embodiment, an acridine compound and a normal aryl amino acid are used as the (C) component. When they are used in combination within the above-mentioned usage ratio range, it is preferred from the viewpoint of suppressing the etching rate when forming a conductor pattern and suppressing the vertical and horizontal differences in wiring width.

[0308] [Other ingredients]

[0309] The photosensitive resin composition of the first embodiment may contain other components in addition to the above-described components (A) to (C). Examples of such other components include leuco dyes, basic dyes, plasticizers, antioxidants, stabilizers, radical polymerization inhibitors, and solvents.

[0310] [Leuco dye]

[0311] The leuco dye can be blended with the photosensitive resin composition of the first embodiment in order to impart suitable color development and excellent peeling properties to the resist cured film.

[0312] Specific examples of leuco dyes include leuco crystal violet (tris[4-(dimethylamino)phenyl]methane), 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-dimethylaminofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl fluoran, 2-(2-chloroanilino)-6-dibutylaminofluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluoran, 1,2-benzo-6-diethylaminofluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-ethylisopentylaminofluoran, 2-methyl-6-(N-p-toluene-N-ethylamino)fluoran, 2-(N-phenyl-N-methylamino)-6-(N-p-toluene-N-ethylamino)fluoran, 2-(3'-trifluoromethylanilino)-6-diethylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 3-methoxy-4-dodecyloxyphenylquinoline, etc. Among them, leuco crystal violet is preferred.

[0313] The content of the leuco dye in the photosensitive resin composition of the first embodiment is preferably 0.6% to 1.6% by mass, more preferably 0.7% to 1.2% by mass. By setting the usage ratio of the leuco dye within this range, good color development and good releasability can be achieved.

[0314] [Basic dyes]

[0315] Examples of the basic dye include Basic Green 1 [CAS No. (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Malachite Green Oxalate [2437-29-8] (e.g., Aizen Malachite Green, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Brilliant Green [633-03-4], Magenta [632-99-5], Methyl Violet [603-47-4], Methyl Violet 2B [8004-87-3], Crystal Violet [548-62-9], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], Diamond Green, etc. Among them, one or more selected from Basic Green 1, malachite green oxalate, Basic Blue 7, and Diamond Green are preferred. Basic Green 1 is particularly preferred from the viewpoint of hue stability and exposure contrast.

[0316] The content of the basic dye in the photosensitive resin composition of the first embodiment is preferably 0.001% to 3% by mass, more preferably 0.01% to 2% by mass, and even more preferably 0.01% to 1.2% by mass. By using the basic dye within this range, both good color development and high sensitivity can be achieved.

[0317] [Solvent]

[0318] The photosensitive resin composition of the first embodiment may be a mixture of the above-mentioned components (A) to (C) and other optional components, or may be used in the form of a photosensitive resin composition prepared by adding an appropriate solvent to these components.

[0319] Examples of the solvent used here include:

[0320] Ketone compounds such as methyl ethyl ketone (MEK);

[0321] alcohols such as ethanol, ethyl alcohol, and isopropyl alcohol;

[0322] wait.

[0323] The proportion of the solvent to be used is preferably such a proportion that the viscosity of the photosensitive resin composition prepared liquid at 25° C. is 500 to 4000 mPa·sec.

[0324] <Photosensitive element>

[0325] In the first embodiment, the photosensitive element is a laminate (photosensitive resin laminate) in which a photosensitive resin layer formed from the photosensitive resin composition is laminated on a support. If necessary, a protective layer may be provided on the surface of the photosensitive resin layer opposite to the support.

[0326] [Support]

[0327] The support is preferably a transparent substrate that transmits light emitted from the exposure light source. Examples of such a support include polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. As needed, stretched films may also be used as these films.

[0328] The haze of the support is preferably 5 or less.

[0329] A thinner support is advantageous in terms of image forming properties and economic efficiency, but strength must be maintained. Considering both, a support with a thickness of 10 μm to 30 μm can be preferably used.

[0330] [Photosensitive resin composition layer]

[0331] When the photosensitive resin composition used for forming the photosensitive resin composition layer contains a solvent, the solvent is preferably removed from the photosensitive resin composition layer, but the solvent may remain.

[0332] The thickness of the photosensitive resin composition layer is preferably 5 μm to 100 μm, more preferably 7 μm to 60 μm. A thinner thickness improves resolution, while a thicker thickness improves film strength. Therefore, the thickness of the composition layer can be appropriately adjusted within the above range depending on the intended use.

[0333] [Protective layer]

[0334] An important characteristic of the protective layer is that its adhesion to the photosensitive resin composition layer is sufficiently weaker than the adhesion between the support and the photosensitive resin composition layer, allowing for easy peeling. Preferred examples of protective layers include polyethylene films and polypropylene films. Furthermore, films with excellent peelability, such as those disclosed in Japanese Patent Application Laid-Open No. 59-202457, can be used.

[0335] The thickness of the protective layer is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm.

[0336] [Method for manufacturing photosensitive element]

[0337] The photosensitive element can be produced by sequentially laminating a support, a photosensitive resin layer, and, if necessary, a protective layer. A known method can be employed for laminating the support, the photosensitive resin layer, and the protective layer.

[0338] For example, a photosensitive resin composition is prepared as the aforementioned photosensitive resin composition liquid, which is first coated onto a support using a bar coater or a roll coater and dried to form a photosensitive resin composition layer on the support. Subsequently, a protective layer is laminated on the formed photosensitive resin composition layer as needed to produce a photosensitive element.

[0339] <Method for Forming Resist Pattern>

[0340] A resist pattern can be formed on a substrate using the above-mentioned photosensitive element.

[0341] The method for forming the resist pattern preferably includes the following steps in sequence:

[0342] A lamination step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate,

[0343] an exposure step of exposing the laminated photosensitive resin composition layer to light, and

[0344] A development step in which the unexposed portion after the exposure is removed using a developer.

[0345] The lamination step is preferably a step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate with a wetting agent interposed therebetween. The wetting agent preferably comprises at least one selected from the group consisting of pure water, deionized water, and electrolyzed water, and a copper chelating agent (e.g., at least one selected from the group consisting of imidazole compounds, triazole compounds, pyridine compounds, and pyrazole compounds).

[0346] In the resist pattern forming method of the first embodiment, first, in a lamination step, a photosensitive resin composition layer is formed on a substrate using a laminator. Specifically, if the photosensitive element has a protective layer, after removing the protective layer, the photosensitive resin composition layer is laminated to the substrate surface using a laminator by heat and pressure bonding.

[0347] As the substrate, a metal plate or an insulating substrate having a metal film is used. Examples of the metal material include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). These substrates may also have through holes for coping with multilayer substrates.

[0348] Here, the photosensitive resin composition layer may be laminated only on one side of the substrate surface, or may be laminated on both sides of the substrate as needed. The heating temperature in this case is preferably 40°C to 160°C. From the perspective of further improving the adhesion of the resulting resist pattern to the substrate, it is preferred to perform heat and pressure bonding two or more times. When performing pressure bonding two or more times, a two-stage laminator equipped with two rollers may be used, or the laminate of the substrate and the photosensitive resin composition layer may be repeatedly passed through the rollers for pressure bonding.

[0349] Next, in the exposure step, the photosensitive resin composition layer is exposed using an exposure machine. This exposure may be performed through the support without peeling the support, or after peeling the support as needed.

[0350] By performing this exposure in a patterned manner, after the development step described later, a resist film (resist pattern) having a desired pattern can be obtained. Patterned exposure can be performed by either a method of exposing through a photomask or a method of maskless exposure. When exposing through a photomask, the exposure amount is determined by the light source illumination and the exposure time. The exposure amount can be measured using a light meter.

[0351] In maskless exposure, exposure is performed directly on the substrate using a drawing device without using a photomask. Light sources include semiconductor lasers with a wavelength of 350nm to 410nm and ultra-high-pressure mercury lamps. The drawing pattern is computer-controlled, and the exposure dose is determined by the illumination of the exposure light source and the substrate's travel speed.

[0352] Next, in the development step, unexposed portions of the photosensitive resin composition layer are removed with a developer. After exposure, if a support exists on the photosensitive resin composition layer, it is preferably removed before subjecting the layer to the development step.

[0353] In the development step, a developer comprising an aqueous alkaline solution is used to remove the unexposed areas, thereby forming a resist image. The aqueous alkaline solution is preferably an aqueous solution of NaCO or KCO, for example. The aqueous alkaline solution is selected based on the properties of the photosensitive resin composition layer, but a NaCO solution with a concentration of 0.2% to 2% by mass is preferably used. The aqueous alkaline solution may also contain a surfactant, a defoaming agent, or a small amount of an organic solvent to promote development.

[0354] The temperature of the developer in the development step is preferably maintained constant within a range of 20°C to 40°C.

[0355] The resist pattern is obtained through the above steps. Depending on the situation, a heating step at 100°C to 300°C may be further performed. This heating step is suitable from the perspective of further improving chemical resistance. Heating can be performed using a heating furnace using a suitable method such as hot air, infrared light, or far infrared light.

[0356] <Circuit Board Formation Method>

[0357] The method for forming a circuit board of the first embodiment preferably includes the following steps in sequence:

[0358] a lamination step of laminating the photosensitive resin composition layer of the photosensitive element on the conductive substrate,

[0359] an exposure step of exposing the laminated photosensitive resin composition layer to light,

[0360] A developing step of removing the unexposed portion after exposure with a developer,

[0361] A conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed by the development, and

[0362] A peeling step of peeling off the resist pattern.

[0363] The lamination step is preferably a step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate with a wetting agent interposed therebetween. The wetting agent preferably comprises at least one selected from the group consisting of pure water, deionized water, and electrolyzed water, and a copper chelating agent (e.g., at least one selected from the group consisting of imidazole compounds, triazole compounds, pyridine compounds, and pyrazole compounds).

[0364] In the conductor pattern forming step, a conductor pattern can be formed on the substrate on which the resist pattern is formed, using a known etching method or plating method on the substrate surface (for example, copper surface) exposed by the development step.

[0365] In the stripping step, the substrate with the conductive pattern formed thereon is brought into contact with an appropriate stripping liquid to remove the resist pattern. This step results in the desired circuit board being obtained.

[0366] The stripping solution used in the stripping step is preferably an alkaline aqueous solution. For example, a 2% to 5% by mass aqueous NaOH solution or a 2% to 5% by mass aqueous KOH solution is preferably used as the alkaline aqueous solution. A small amount of a water-soluble solvent, such as an alcohol, may be added to the stripping solution. The temperature of the stripping solution in the stripping step is preferably 40°C to 70°C.

[0367] Generally, in conductor pattern formation by etching, regardless of the etching rate, the etching time required to achieve the desired wiring width can be adjusted by adjusting, for example, the transport speed of the etching line. However, if the etching rate is too high, the transport speed also becomes too high, sometimes leading to problems such as the inability to set the etching time practically.

[0368] Furthermore, in recent years, circuit board manufacturing has typically been conducted in an assembly line where substrates are transported in a fixed direction and processed sequentially. This means that conductor lines may be parallel (in the MD direction), perpendicular (in the TD direction), or skewed relative to the substrate transport direction. In particular, at high etching rates, the vertical and horizontal differences in wiring width tend to become more pronounced.

[0369] The present inventors have conducted intensive studies and have found that, when a photosensitive resin composition forming a cured resist pattern has specific physical properties, a resist material can be provided that suppresses vertical and horizontal variations in wiring width when forming a fine conductor pattern in an in-line manner.

[0370] That is, the photosensitive resin composition of the first embodiment has the following characteristics: a photosensitive resin layer formed from the above-mentioned photosensitive resin composition is laminated with a thickness of 25 μm on a copper-clad laminate laminated with a copper foil having a thickness of 18 μm, a cured resist pattern is formed by light irradiation and development treatment in a pattern with a line / space = 50 μm / 30 μm, and a copper etching treatment is performed at 50°C for 55 seconds. The bottom width of the copper line pattern obtained by removing the above-mentioned cured resist pattern is 38 μm or more (preferably 38 μm to 50 μm, more preferably 40 μm to 45 μm).

[0371] The resist pattern swells and shrinks during each of the development, water washing, and etching steps, with the swelling and shrinkage being particularly pronounced during the water washing step. This swelling and shrinkage of the resist pattern is believed to reduce the adhesion between the wiring and the resist pattern. The resist pattern formed from the photosensitive resin composition of the first embodiment is believed to swell and shrink less during any of the development, water washing, and etching steps, making etching less likely at the interface between the resist pattern and the wiring, thereby suppressing vertical and horizontal variations in wiring width.

[0372] In the first embodiment, a specific photosensitive resin composition is selected by focusing on the characteristics (the bottom width of the conductor line width is a certain value or more) when a specific analysis method (specific etching conditions) is used as a means for achieving the effects of the invention.

[0373] It should be noted that the bottom width of the conductor line width can be adjusted by appropriately setting the composition of the photosensitive resin composition.

[0374] Furthermore, the conductor pattern (wiring) formed by the circuit board forming method of the first embodiment described above can minimize the vertical and horizontal differences in the conductor pattern's wiring width. The vertical and horizontal differences in wiring width are represented by the difference between the conductor line's wiring width in the TD direction (TD) and the conductor line's wiring width in the MD direction (MD), or TD-MD.

[0375] The absolute value of the vertical and horizontal difference in the wiring width in the conductive pattern formed by the conductive pattern forming method of the first embodiment is preferably 0 μm to 5 μm, more preferably 0 μm to 3 μm.

[0376] The photosensitive resin composition, photosensitive element, and circuit board forming method of the first embodiment can be extremely suitably used in the production of, for example, printed wiring boards, lead frames, substrates having concavo-convex patterns, semiconductor packages, and the like.

[0377] It should be noted that the measurement methods of the above-mentioned various parameters were measured according to the measurement methods in the examples described later unless otherwise specified.

[0378] <Second embodiment>

[0379] Hereinafter, a mode for implementing the second embodiment of the present invention (hereinafter simply referred to as “the second embodiment”) will be described in detail.

[0380] <Photosensitive resin composition>

[0381] In the second embodiment, the photosensitive resin composition contains the following components (A) to (C).

[0382] (A) Component: Alkali-soluble polymer with an acid equivalent of 100 to 600,

[0383] (B) Component: a compound having an ethylenic double bond, and

[0384] Component (C): photopolymerization initiator.

[0385] [(A) Component: Alkali-soluble polymer]

[0386] The component (A) has an acid equivalent of 100 to 600 (preferably 200 to 500, more preferably 250 to 450) and contains a copolymer containing 50% by mass or more of styrene units. In this specification, the styrene unit refers to substituted or unsubstituted styrene. The substituents are not particularly limited, and examples thereof include alkyl groups, halogen groups, and hydroxyl groups.

[0387] The component (A) is a copolymer of a styrene derivative and other monomers such as preferably an acid monomer.

[0388] Examples of the acid monomer include (meth)acrylic acid, pentenoic acid, unsaturated dicarboxylic anhydride, and hydroxystyrene. Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, itaconic anhydride, fumaric acid, and citraconic anhydride. Among them, (meth)acrylic acid is preferred.

[0389] Examples of other monomers include unsaturated aromatic compounds (sometimes referred to as “aromatic monomers”), alkyl (meth)acrylates, aralkyl (meth)acrylates, conjugated diene compounds, polar monomers, and crosslinking monomers.

[0390] Examples of the unsaturated aromatic compound include vinylnaphthalene.

[0391] The term "alkyl (meth)acrylate" is a concept encompassing both chain alkyl esters and cyclic alkyl esters. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate.

[0392] Respectively, as the aralkyl (meth)acrylate, for example, benzyl (meth)acrylate and the like can be cited;

[0393] Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene.

[0394] Examples of polar monomers include:

[0395] Hydroxyl-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and pentenol;

[0396] Amino-containing monomers such as 2-aminoethyl methacrylate;

[0397] (Meth) acrylamide, N-hydroxymethyl (meth) acrylamide and other amide-containing monomers;

[0398] Acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-cyanoethyl acrylate and other cyano group-containing monomers;

[0399] Epoxy-containing monomers such as glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate;

[0400] wait.

[0401] Examples of the crosslinkable monomer include trimethylolpropane triacrylate and divinylbenzene.

[0402] The component (A) is particularly preferably a copolymer of (meth)acrylic acid, styrene, and other monomers.

[0403] The component (A) contains a copolymer 1 containing 50% by mass or more of styrene units. The amount of styrene units in the copolymer 1 is preferably 50% by mass to 80% by mass, more preferably 51% by mass to 70% by mass.

[0404] The component (A) in the second embodiment may consist solely of the copolymer 1 or may be a mixture of the copolymer 1 and another polymer. The content of the copolymer 1 in the component (A) is preferably 5% to 90% by mass, more preferably 10% to 80% by mass, and even more preferably 20% to 70% by mass.

[0405] As the other polymer, a copolymer of the above-described acid monomer and other monomers, which does not belong to the copolymer 1 (copolymer 2) is suitable.

[0406] The weight average molecular weight of component (A) (when component (A) comprises a plurality of copolymers, the weight average molecular weight of the entire mixture) is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 15,000 to 100,000. Adjusting the weight average molecular weight of component (A) within this range is preferred from the perspective of adapting the development time during resist pattern formation to the operating conditions of the production line used. The copolymer dispersity, represented by the ratio of the weight average molecular weight to the number average molecular weight of component (A), is preferably 1 or more and 6 or less.

[0407] In the second embodiment, the content of component (A) in the photosensitive resin composition is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 40% to 60% by mass, based on the total solid content of the photosensitive resin composition (hereinafter, unless otherwise specified, the same shall apply to each component). This content is preferably 10% by mass or more from the viewpoint of maintaining alkali developability, and is preferably 90% by mass or less from the viewpoint of fully exhibiting the performance of the resist pattern formed by exposure.

[0408] [Component (B): Compound having an olefinic double bond]

[0409] The component (B) is not particularly limited as long as it has one or more ethylenic double bonds. However, the component (B) in the second embodiment includes a compound represented by the following general formula (I) as an essential compound (B1).

[0410]

[0411] {In the formula, R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n1, n2, and n3 are independently integers of 0 to 30, wherein n1+n2+n3≥6 is satisfied.}

[0412] In formula (I), R is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom. n1, n2, and n3 are preferably an integer of 1 to 30, more preferably an integer of 3 to 21, each independently of each other.

[0413] In formula (I), the value of n1+n2+n3 is preferably greater than 9 and 20 or less, and more preferably 15 or more and 20 or less, from the viewpoint of improving the developing dispersibility.

[0414] In formula (I), from the viewpoint of improving the developing dispersibility, it is preferred that at least one R is a hydrogen atom, and it is more preferred that all R are hydrogen atoms.

[0415] Furthermore, in formula (I), from the viewpoint of achieving both developer dispersibility and adhesion, it is particularly preferred that all Rs are hydrogen atoms and the value of n1+n2+n3 is 15 or more and 20 or less.

[0416] The compound represented by formula (I) can be synthesized using a known method. For example, it can be obtained by adding 3 mol of (meth)acrylic acid or transesterifying an adduct obtained by adding 6 equivalents or more of ethylene oxide to trimethylolpropane.

[0417] Preferred specific examples of the compound represented by formula (I) include ethylene oxide (EO)-modified trimethylolpropane tri(meth)acrylate (the total number of EO added moles is 6 to 20).

[0418] The component (B) in the second embodiment may be composed of the compound (B1) alone, or may be a mixture of the compound (B1) and other components (B).

[0419] When the component (B) of the second embodiment is a mixture, the content of the compound (B1) in the mixture is preferably 10% by mass or more, more preferably 10% by mass to 50% by mass, and even more preferably 15% by mass to 35% by mass, based on the total mass of the mixture.

[0420] The content of the compound (B1) in the photosensitive resin composition of the second embodiment is preferably 5% by mass or more, more preferably 5.5% by mass to 30% by mass, and even more preferably 6% by mass to 20% by mass based on the total solid content of the photosensitive resin composition.

[0421] Here, the mechanism by which a photosensitive resin composition having excellent both developing dispersibility and fine pattern adhesion is achieved by including an alkali-soluble polymer having a specific acid equivalent and a specific amount of styrene units, the aforementioned component (B1), and acridine is not yet clear, but it is speculated that the interaction between the styrene unit and the acridine component (based on π electron stacking) and the interaction between the acid monomer and the aforementioned component (B1) (based on hydrogen bonding) are well manifested, and the overall compatibility is improved, which is beneficial to the above-mentioned characteristics.

[0422] In the second embodiment, from the viewpoint of developer dispersibility, component (B) preferably contains a pentaerythritol-modified monomer (hereinafter referred to as "compound (B2)") together with compound (B1). Compound (B2) is preferably a tetra(meth)acrylate of a polyol obtained by adding an average of preferably 4 to 35 mol, more preferably 8 to 28 mol, and even more preferably 12 to 20 mol of alkylene oxide to pentaerythritol.

[0423] The content of the compound (B2) in the component (B) is preferably 10% by mass to 40% by mass, more preferably 15% by mass to 30% by mass, based on the total mass of the component (B).

[0424] The content of the compound (B2) in the photosensitive resin composition of the second embodiment is preferably 1% by mass or more, more preferably 1% by mass to 20% by mass, and even more preferably 5% by mass to 15% by mass.

[0425] The component (B) may contain a compound having an ethylenic double bond other than the compounds (B1) and (B2).

[0426] Component (B) may also include the following:

[0427] Bisphenol A compounds, for example, di(meth)acrylates of polyalkylene glycols obtained by adding an average of 2 to 15 mol of alkylene oxide to both ends of bisphenol A;

[0428] Compounds having three ethylenic double bonds (excluding B1), for example, tri(meth)acrylates of polyalkylene triols obtained by adding an average of 3 to 25 mol of alkylene oxide to trimethylolpropane.

[0429] The content of component (B) in the photosensitive resin composition of the second embodiment is preferably 1% to 70% by mass, more preferably 5% to 60% by mass, and even more preferably 10% to 50% by mass. From the perspective of suppressing curing defects and development time delays, the content is preferably 1% by mass or more, while from the perspective of suppressing the formation of aggregates in the developer, it is preferably 70% by mass or less.

[0430] [Component (C): Photopolymerization initiator]

[0431] The component (C) generates radicals capable of initiating polymerization of the component (B) upon irradiation with light.

[0432] In the second embodiment, an acridinium compound can be used as the photopolymerization initiator (B). Furthermore, an acridinium compound can be used in combination with other photopolymerization initiators. The acridinium compound is preferably used to improve the sensitivity and resolution of the photosensitive resin composition of the second embodiment.

[0433] Examples of the acridine compound include 1,7-bis(9,9'-acridinyl)heptane, 9-phenylacridine, 9-methylacridine, 9-ethylacridine, 9-chloroethylacridine, 9-methoxyacridine, 9-ethoxyacridine, 9-(4-methylphenyl)acridine, 9-(4-ethylphenyl)acridine, 9-(4-n-propylphenyl)acridine, 9-(4-n-butylphenyl)acridine, 9-(4-tert-butylphenyl)acridine, 9-(4-methoxyphenyl)acridine, 9-(4-ethoxyphenyl)acridine, 9-(4-acetyl)acridine, phenyl)acridine, 9-(4-dimethylaminophenyl)acridine, 9-(4-chlorophenyl)acridine, 9-(4-bromophenyl)acridine, 9-(3-methylphenyl)acridine, 9-(3-tert-butylphenyl)acridine, 9-(3-acetylphenyl)acridine, 9-(3-dimethylaminophenyl)acridine, 9-(3-diethylaminophenyl)acridine, 9-(3-chlorophenyl)acridine, 9-(3-bromophenyl)acridine, 9-(2-pyridyl)acridine, 9-(3-pyridyl)acridine, 9-(4-pyridyl)acridine, and the like.

[0434] Examples of other photopolymerization initiators include:

[0435] 2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylimidazolyl dimer, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylimidazolyl dimer, 2,4,5-tris-(o-chlorophenyl)-diphenylimidazolyl dimer, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl) )-imidazolyl dimer, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, -bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4 Hexaarylbiimidazole compounds such as 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, and 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer;

[0436] 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer (excluding the above-mentioned hexaarylbiimidazole compounds);

[0437] Aromatic ketones such as benzophenone, N,N'-tetramethyl-4,4'-dimethylaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1;

[0438] Quinone compounds such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone;

[0439] Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether;

[0440] Benzil derivatives such as benzil methyl ketal;

[0441] N-phenylglycine derivatives, coumarin compounds, 4,4'-bis(diethylamino)benzophenone, etc.

[0442] The content of the acridine compound in the photosensitive resin composition of the second embodiment is preferably within a range of 0.001 to 2 mass%, more preferably 0.01 to 1.5 mass%, and even more preferably 0.1 to 1 mass%.

[0443] The content of the component (C) in the photosensitive resin composition of the second embodiment (the content of the entire component (C) including the acridine compound) is preferably 0.1 to 2 mass%, more preferably 0.2 to 1.8 mass%, further preferably 0.3 to 1.7 mass%, particularly preferably 0.4 to 1.6 mass%.

[0444] From the viewpoint of improving sensitivity and resolution, the component (C) may further contain a sensitizer. Examples of such a sensitizer include N-arylamino acids, organic halogen compounds, and other sensitizers.

[0445] Respectively, examples of the above-mentioned N-aryl amino acids include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine;

[0446] Examples of the organic halogen compound include amyl bromide, isopentyl bromide, isobutylene bromide, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and chlorinated triazine compounds.

[0447] Examples of the other sensitizers include:

[0448] Quinone compounds such as 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone;

[0449] Aromatic ketone compounds such as benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4,4'-bis(diethylamino)benzophenone;

[0450] Benzoin ether compounds such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, and ethyl benzoin;

[0451] Benzil dimethyl ketal, benzil diethyl ketal, 1-phenyl-1,2-propanedione-2-O-benzoyl oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime and other oxime ester compounds;

[0452] wait.

[0453] From the viewpoint of the sensitivity of the composition and the releasability of the cured resist film, the content of the sensitizer in the photosensitive resin composition of the second embodiment is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably 0.1 to 2% by mass.

[0454] [Other ingredients]

[0455] The photosensitive resin composition of the second embodiment may contain other components in addition to the components (A) to (C) described above. Examples of other components include a coloring matter, a halogen compound, a stabilizer, and a solvent.

[0456] Respectively, as the coloring matter, leuco dyes and other coloring matters can be cited;

[0457] Examples of the stabilizer include radical polymerization inhibitors, benzotriazole compounds, and carboxybenzotriazole compounds.

[0458] Leuco dyes

[0459] Examples of the leuco dye include tris(4-dimethylaminophenyl)methane [leuco crystal violet] and bis(4-dimethylaminophenyl)phenylmethane [leuco malachite green]. In particular, leuco crystal violet is preferably used from the viewpoint of good contrast.

[0460] The content of the leuco dye in the photosensitive resin composition is preferably 0.1% to 10% by mass. Adjusting the content of the leuco dye to 0.1% by mass or more is preferred from the perspective of obtaining a high contrast between the exposed and unexposed portions, while adjusting the content to 10% by mass or less is preferred from the perspective of maintaining storage stability.

[0461] <Other coloring substances>

[0462] Examples of other coloring substances include fuchsin, phthalocyanine green, auramine base, paramagenta, crystal violet, methyl orange, Nile Blue 2B, Victoria Blue, malachite green (Aizen (registered trademark) MALACHITE GREEN manufactured by Hodogaya Chemical Co., Ltd.), Basic Blue 20, and diamond green (Aizen (registered trademark) DIAMOND GREEN GH manufactured by Hodogaya Chemical Co., Ltd.).

[0463] The content of other coloring substances in the photosensitive resin composition is preferably 0.001% by mass to 1% by mass. Adjusting the content to 0.001% by mass or more is preferred from the perspective of improving handling properties, while adjusting the content to 1% by mass or less is preferred from the perspective of maintaining storage stability.

[0464] Halogen compounds

[0465] From the viewpoint of adhesion and contrast, it is a preferred embodiment to use a leuco dye and the following halogen compound in combination in the photosensitive resin composition.

[0466] Examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and triazine chloride compounds. Tribromomethylphenylsulfone is particularly preferred. A halogen compound content of 0.01% to 3% by mass in the photosensitive resin composition is preferred from the perspective of maintaining the storage stability of the hue of the photosensitive layer.

[0467] <Radical polymerization inhibitor, benzotriazole compound, and carboxybenzotriazole compound>

[0468] Examples of the radical polymerization inhibitor include 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), nitrosophenylhydroxylamine aluminum salt, and diphenylnitrosamine.

[0469] Examples of the benzotriazole compound include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, and bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole.

[0470] Examples of the carboxybenzotriazole compound include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, N-(N,N-di-2-ethylhexyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-hydroxyethyl)aminomethylenecarboxybenzotriazole, and N-(N,N-di-2-ethylhexyl)aminoethylenecarboxybenzotriazole.

[0471] The total content of the radical polymerization inhibitor, benzotriazole compound, and carboxybenzotriazole compound in the photosensitive resin composition is preferably 0.01% to 3% by mass, more preferably 0.05% to 1% by mass. Adjusting the content to 0.01% by mass or greater is preferred from the perspective of imparting storage stability to the photosensitive resin composition, while adjusting the content to 3% by mass or less is preferred from the perspective of maintaining sensitivity and suppressing dye discoloration.

[0472] Plasticizers

[0473] The photosensitive resin composition may contain a plasticizer as needed. Examples of the plasticizer include phthalic acid esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, acetyl triethyl citrate, acetyl tri-n-propyl citrate, acetyl tri-n-butyl citrate, polyethylene glycol, polypropylene glycol, polyethylene glycol alkyl ether, and polypropylene glycol alkyl ether.

[0474] The content of the plasticizer in the photosensitive resin composition is preferably 1% to 50% by mass, more preferably 1% to 30% by mass. Adjusting the content to 1% by mass or more is preferred from the viewpoint of suppressing delays in development time and imparting flexibility to the cured film. On the other hand, adjusting the content to 50% by mass or less is preferred from the viewpoint of suppressing insufficient curing and edge fusion.

[0475] Solvents

[0476] The photosensitive resin composition may also contain a solvent. Examples of the solvent include ketones such as methyl ethyl ketone (MEK) and alcohols such as methanol, ethanol, and isopropyl alcohol. The solvent is preferably added to the photosensitive resin composition such that the viscosity of the solution of the photosensitive resin composition applied to the support film is 500 to 4000 mPa·s at 25°C.

[0477] <Photosensitive element>

[0478] In the second embodiment, the photosensitive element is a laminate (photosensitive resin laminate) in which a photosensitive resin layer formed from the above-mentioned photosensitive resin composition is laminated on a support. The photosensitive element may also have a protective layer on the surface of the photosensitive resin layer opposite to the support, as needed.

[0479] [Support]

[0480] The support is preferably a transparent substrate that transmits light emitted from the exposure light source. Examples of the support include polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. These films may also be stretched films as needed.

[0481] The haze of the support is preferably 5 or less.

[0482] A thinner support is advantageous in terms of image forming properties and economic efficiency, but strength must be maintained. Considering both, a support with a thickness of 10 μm to 30 μm can be preferably used.

[0483] [Photosensitive resin layer]

[0484] When the photosensitive resin composition used for forming the photosensitive resin layer contains a solvent, the solvent is preferably removed from the photosensitive resin layer, but may remain in the photosensitive resin layer.

[0485] The thickness of the photosensitive resin layer is preferably 5 μm to 100 μm, more preferably 7 μm to 60 μm. Thinner thicknesses improve resolution, while thicker thicknesses increase film strength. Therefore, the thickness of the photosensitive resin layer can be appropriately selected within the range of 5 μm to 100 μm depending on the intended use.

[0486] [Protective layer]

[0487] An important characteristic of the protective layer is that its adhesion to the photosensitive resin layer is sufficiently weaker than the adhesion between the support and the photosensitive resin layer, allowing for easy peeling. Preferred examples of the protective layer include polyethylene films and polypropylene films, as well as films with excellent peelability, such as those disclosed in Japanese Patent Application Laid-Open No. 59-202457.

[0488] The thickness of the protective layer is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm.

[0489] [Method for manufacturing photosensitive element]

[0490] The photosensitive element can be produced by sequentially laminating a support, a photosensitive resin layer, and, if necessary, a protective layer. A known method can be employed for laminating the support, the photosensitive resin layer, and the protective layer.

[0491] For example, a solvent is added to a photosensitive resin composition and mixed to prepare a prepared solution. This solution is then coated onto a support using a bar coater or a roll coater and dried to form a photosensitive resin layer formed from the photosensitive resin composition on the support. Subsequently, a protective layer is laminated on the formed photosensitive resin layer as needed to produce a photosensitive element.

[0492] <Method for Forming Resist Pattern>

[0493] A resist pattern can be formed on a substrate using the above-mentioned photosensitive element.

[0494] The method for forming the resist pattern preferably includes the following steps in sequence:

[0495] A lamination step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate,

[0496] an exposure step of exposing the stacked photosensitive resin layer to light, and

[0497] A development step in which the unexposed portion after the exposure is removed using a developer.

[0498] The lamination step is preferably a step of laminating the photosensitive resin layer of the photosensitive element onto the conductive substrate with a wetting agent interposed therebetween. The wetting agent preferably comprises at least one selected from the group consisting of pure water, deionized water, and electrolyzed water, and a copper chelating agent (e.g., at least one selected from the group consisting of imidazole compounds, triazole compounds, pyridine compounds, and pyrazole compounds).

[0499] In the method for forming a resist pattern according to the second embodiment, first, in a lamination step, a photosensitive resin layer is formed on a substrate using a laminator. Specifically, if the photosensitive element has a protective layer, the protective layer is removed and then the photosensitive resin layer is laminated to the substrate surface using a laminator by heat and pressure bonding.

[0500] As the substrate, a metal plate or an insulating substrate having a metal film is used. Examples of the metal material include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). These substrates may also have through holes for coping with multilayer substrates.

[0501] The photosensitive resin layer may be laminated to only one side of the substrate surface, or may be laminated to both sides of the substrate as needed. The heating temperature during lamination is preferably 40°C to 160°C. From the perspective of further improving the adhesion of the resulting resist pattern to the substrate, it is preferred to perform heat and pressure bonding two or more times. When performing pressure bonding two or more times, a two-stage laminator equipped with two rollers may be used, or the laminate of the substrate and the photosensitive resin layer may be repeatedly passed through the rollers for pressure bonding.

[0502] Next, in the exposure step, the photosensitive resin layer is exposed using an exposure machine. The exposure may be performed through the support without peeling the support, or after peeling the support as needed.

[0503] By performing this exposure in a patterned manner, after the development step described later, a resist film (resist pattern) having a desired pattern can be obtained. Patterned exposure can be performed by either a method of exposing through a photomask or a method of maskless exposure. When exposing through a photomask, the exposure amount is determined by the light source illumination and the exposure time. The exposure amount can be measured using a light meter.

[0504] In maskless exposure, exposure is performed directly on the substrate using a drawing device without using a photomask. Light sources include semiconductor lasers with a wavelength of 350nm to 410nm and ultra-high-pressure mercury lamps. The drawing pattern is computer-controlled, and the exposure dose is determined by the illumination of the exposure light source and the substrate's travel speed.

[0505] Next, in the development step, unexposed portions of the photosensitive resin layer are removed with a developer. If a support is present on the photosensitive resin layer after exposure, it is preferably removed before the development step.

[0506] In the development step, a developer consisting of an alkaline aqueous solution is used to remove the unexposed areas, thereby forming a resist image. The alkaline aqueous solution is preferably an aqueous solution of Na2CO3, K2CO3, or the like. The alkaline aqueous solution is selected based on the characteristics of the photosensitive resin layer, but a Na2CO3 aqueous solution with a concentration of 0.2% to 2% by mass is preferably used. The alkaline aqueous solution may also contain a surfactant, defoaming agent, or a small amount of an organic solvent to promote development.

[0507] The temperature of the developer in the development step is preferably maintained constant within a range of 20°C to 40°C.

[0508] The resist pattern is obtained through the above steps. Depending on the situation, a heating step at 100°C to 300°C may be further performed. This heating step is suitable from the perspective of further improving chemical resistance. Heating can be performed using a heating furnace using a suitable method such as hot air, infrared light, or far infrared light.

[0509] <Circuit Board Formation Method>

[0510] The method for forming a circuit board of the second embodiment preferably includes the following steps in sequence:

[0511] A lamination step of laminating the photosensitive resin layer of the photosensitive element on the conductive substrate,

[0512] an exposure step of exposing the stacked photosensitive resin layer to light,

[0513] A developing step of removing the unexposed portion after exposure with a developer,

[0514] A conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed by the development, and

[0515] A peeling step of peeling off the resist pattern.

[0516] The lamination step is preferably a step of laminating the photosensitive resin layer of the photosensitive element onto the conductive substrate with a wetting agent interposed therebetween. The wetting agent preferably comprises at least one selected from the group consisting of pure water, deionized water, and electrolyzed water, and a copper chelating agent (e.g., at least one selected from the group consisting of imidazole compounds, triazole compounds, pyridine compounds, and pyrazole compounds).

[0517] In the conductor pattern forming step, a conductor pattern can be formed on the substrate on which the resist pattern is formed, using a known etching method or plating method on the substrate surface (for example, copper surface) exposed by the development step.

[0518] In the stripping step, the substrate with the conductive pattern formed thereon is brought into contact with an appropriate stripping liquid to remove the resist pattern. This step yields the desired circuit board.

[0519] The stripping solution used in the stripping step is preferably an aqueous alkaline solution. For example, a 2% to 5% by mass aqueous NaOH solution or KOH solution is preferably used as the aqueous alkaline solution. A small amount of a water-soluble solvent, such as alcohol, may also be added to the stripping solution. The temperature of the stripping solution during the stripping step is preferably 40°C to 70°C.

[0520] The photosensitive resin composition, photosensitive element, and circuit board forming method of the second embodiment can be extremely suitably used in the production of, for example, printed wiring boards, lead frames, substrates having concavo-convex patterns, semiconductor packages, and the like.

[0521] It should be noted that the measurement methods of the above-mentioned various parameters were measured according to the measurement methods in the examples described later unless otherwise specified.

[0522] <Third embodiment>

[0523] Hereinafter, a mode for implementing a third embodiment of the present invention (hereinafter also simply referred to as “this third embodiment”) will be described in detail.

[0524] <Photosensitive resin composition>

[0525] In the third embodiment, the photosensitive resin composition comprises (A) an alkali-soluble polymer, (B) an ethylenically unsaturated bond-containing compound, and (C) a photopolymerization initiator. If desired, the photosensitive resin composition may further comprise other components such as (D) additives.

[0526] In this specification, “(meth)acrylic acid” refers to acrylic acid or methacrylic acid, “(meth)acryloyl” refers to acryloyl or methacryloyl, and “(meth)acrylate” refers to “acrylate” or “methacrylate”.

[0527] (A) Alkali-soluble polymer

[0528] The alkali-soluble polymer (A) is a polymer that is soluble in an alkali substance. In the third embodiment, from the perspective of achieving both the pore-blocking properties of the resist pattern and the ability to suppress water-residual short-circuit failures, the alkali-soluble polymer (A) preferably contains 10% to 24% by mass of (meth)acrylic acid structural units and 35% to 90% by mass of styrene structural units, based on the total mass of the monomers constituting the alkali-soluble polymer (A).

[0529] The content of the (meth)acrylic acid structural unit in the alkali-soluble polymer (A) is preferably 24% by mass or less from the perspective of suppressing water-residual short-circuiting failures, and preferably 10% by mass or more from the perspective of ensuring alkali developability and alkali strippability, based on the total mass of the monomers constituting the alkali-soluble polymer (A). The upper limit of this content is more preferably 23% by mass or 22.5% by mass, and the lower limit is more preferably 11% by mass, 15% by mass, 18% by mass, or 20% by mass. Water-residual short-circuiting failures are strongly related to the hydrophobicity of the cured resist, and water-residual short-circuiting failures can be suppressed by increasing the hydrophobicity of the resist, i.e., the water contact angle.

[0530] The acid equivalent of the alkali-soluble polymer (A) (the acid equivalent of the entire mixture when component (A) comprises multiple copolymers) is preferably 100 or greater from the perspective of the development resistance of the photosensitive resin layer and the development resistance, resolution, and adhesion of the resist pattern, and is preferably 900 or less from the perspective of the developability and releasability of the photosensitive resin layer. The acid equivalent of the alkali-soluble polymer (A) is more preferably 250 to 600, and even more preferably 350 to 500. The acid equivalent refers to the mass of a linear polymer having one equivalent of carboxyl groups therein.

[0531] The content of the structural unit of styrene in the alkali-soluble polymer (A) is preferably 90% by mass or less from the perspective of developability, and preferably 35% by mass or more from the perspective of resolution and suppression of residual water short-circuiting failures, based on the total mass of the monomers constituting the alkali-soluble polymer (A). The upper limit of the content is more preferably 85% by mass, 80% by mass, 70% by mass, or 60% by mass from the perspective of developability and prevention of delayed peeling time, and the lower limit is more preferably 36% by mass, 38% by mass, 40% by mass, or 42% by mass from the perspective of resolution and suppression of residual water short-circuiting failures.

[0532] From the viewpoint of improving the pore-blocking properties of the resist pattern, it is preferred that the alkali-soluble polymer (A) further contain a structural unit of butyl (meth)acrylate. The structural unit of butyl (meth)acrylate may also contain a repeating unit derived from at least one selected from the group consisting of n-butyl (meth)acrylate, isobutyl (meth)acrylate, and tert-butyl (meth)acrylate.

[0533] From the viewpoint of achieving both the hole-covering property and the ability to suppress water-residual short-circuit failure, the content of the structural unit of butyl (meth)acrylate in the alkali-soluble polymer (A) is preferably within a range of 0.1 to 5% by mass, more preferably 0.3 to 1% by mass, based on the total mass of the monomers constituting the alkali-soluble polymer (A).

[0534] The alkali-soluble polymer (A) may be a single copolymer, a mixture of multiple copolymers, and / or a mixture of multiple homopolymers, as long as it contains 10% to 24% by mass of (meth)acrylic acid structural units and 35% to 90% by mass of styrene structural units based on the total mass of the monomers constituting the alkali-soluble polymer (A).

[0535] (A) The alkali-soluble polymer may include poly(meth)acrylic acid, polybutyl(meth)acrylate, polystyrene, or a copolymer obtained by copolymerizing (meth)acrylic acid and / or styrene with one or more first monomers and / or one or more second monomers described below.

[0536] The first monomer is a monomer containing a carboxyl group in the molecule (excluding (meth)acrylic acid). Examples of the first monomer include fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, and maleic acid half ester.

[0537] The second monomer is a non-acidic monomer (excluding styrene) having at least one polymerizable unsaturated group in the molecule. Examples of the second monomer include esters of vinyl alcohol such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, and vinyl acetate; (meth)acrylonitrile; and polymerizable styrene derivatives.

[0538] Among them, from the viewpoint of improving the hole-blocking property of the resist pattern, n-butyl (meth)acrylate, isobutyl (meth)acrylate, or tert-butyl (meth)acrylate is preferred, and from the viewpoint of hole-blocking property, n-butyl (meth)acrylate is more preferred. Furthermore, from the viewpoint of improving resolution and suppressing water residual short-circuit failure, a polymerizable styrene derivative is preferred.

[0539] Examples of the polymerizable styrene derivative include methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, 4-vinylbenzoic acid, styrene dimer, and styrene trimer.

[0540] Alkali-soluble polymers are preferably synthesized by adding an appropriate amount of a free radical polymerization initiator, such as benzoyl peroxide or azoisobutyronitrile, to a solution prepared by mixing the above-mentioned monomers and diluting the mixture with a solvent, such as acetone, methyl ethyl ketone, methanol, ethanol, n-propanol, or isopropanol, followed by heating and stirring. Synthesis can also be performed by dropwise adding a portion of the mixture to the reaction solution. Alternatively, further solvent may be added after the reaction to adjust the concentration to the desired level. In addition to solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization can also be used as a synthesis method.

[0541] The weight-average molecular weight of the alkali-soluble polymer (A) (when component (A) comprises a plurality of copolymers, the weight-average molecular weight of the entire mixture) is preferably 5,000 to 500,000. The weight-average molecular weight of the alkali-soluble polymer (A) is preferably 5,000 or greater from the perspective of maintaining uniform thickness of the dry film resist and achieving resistance to a developer, and is preferably 500,000 or less from the perspective of maintaining the developability of the dry film resist. The weight-average molecular weight of the alkali-soluble polymer (A) is more preferably 10,000 to 200,000, and even more preferably 20,000 to 100,000. The degree of dispersion of the alkali-soluble polymer (A) is preferably 1.0 to 6.0.

[0542] In the third embodiment, the content of the alkali-soluble polymer (A) in the photosensitive resin composition is preferably within a range of 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 40% to 60% by mass, based on the total solids content of the photosensitive resin composition (hereinafter, unless otherwise specified, the same shall apply to all components contained). The content of the alkali-soluble polymer (A) is preferably 10% by mass or greater from the perspective of maintaining the alkali developability of the photosensitive resin layer, and is preferably 90% by mass or less from the perspective of fully exhibiting the performance of the resist material in the resist pattern formed by exposure.

[0543] (B) Compounds containing ethylenically unsaturated bonds

[0544] (B) The ethylenically unsaturated bond-containing compound is a compound having polymerizability by having an ethylenically unsaturated group in its structure. From the viewpoint of addition polymerizability, the ethylenically unsaturated bond is preferably a terminal ethylenically unsaturated group.

[0545] In the third embodiment, when (A) an alkali-soluble polymer and (B) an ethylenically unsaturated bond-containing compound are used in combination, the weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is preferably 1200 or more from the viewpoint of ensuring the pore-blocking properties of the resist pattern. In this specification, the weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound means the weight average molecular weight derived from the structural formula of the single ethylenically unsaturated bond-containing compound when the (B) ethylenically unsaturated bond-containing compound is a single compound, and means the weighted average of the weight average molecular weights of the individual ethylenically unsaturated bond-containing compounds and the blending ratio when the (B) ethylenically unsaturated bond-containing compound is composed of multiple compounds.

[0546] The weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is more preferably 1300 or more, further preferably 1400 or more, from the viewpoint of further improving the pore-blocking properties of the resist pattern, and is more preferably 5000 or less, further preferably 4000 or less, and particularly preferably 3000 or less, from the viewpoint of the resolution and peelability of the resist pattern.

[0547] (B) The ethylenically unsaturated bond-containing compound may include at least one selected from the group consisting of the following (b1) to (b5):

[0548] (b1) an ethylene glycol di(meth)acrylate compound represented by the following general formula (I):

[0549]

[0550] {wherein, R1 and R2 independently represent a hydrogen atom or a methyl group, and m1 is a number satisfying 2 to 40.};

[0551] (b2) an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the following general formula (II):

[0552]

[0553] {wherein, R3 and R4 independently represent a hydrogen atom or a methyl group, A is C2H4, B is C3H6, n1, n2, n3, and n4 are integers satisfying the relationship n1+n2+n3+n4=2 to 50, and the arrangement of the repeating units of -(AO)- and -(BO)- may be random or block. In the case of block arrangement, either -(AO)- or -(BO)- may be on the side of the biphenyl group.};

[0554] (b3) a tri(meth)acrylate compound represented by the following general formula (III):

[0555]

[0556] {wherein, R5 to R7 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3, and m4 independently represent integers of 0 to 40, m2+m3+m4 is 1 to 40, and when m2+m3+m4 is 2 or more, multiple Xs may be the same or different};

[0557] (b4) a urethane di(meth)acrylate compound represented by the following general formula (IV):

[0558]

[0559] {wherein, R8 and R9 independently represent a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 6 carbon atoms, Z represents a divalent organic group, and s and t independently represent integers of 0 to 40, and s+t≥1}; and (b5) addition polymerizable monomers other than the above-mentioned (b1) to (b4).

[0560] From the viewpoint of adjusting the peeling time of the resist pattern and the size of the peelable sheet, the (B) ethylenically unsaturated bond-containing compound preferably includes (b1) an ethylene glycol di(meth)acrylate compound represented by the general formula (I).

[0561] In general formula (I), m1 is preferably 2 or more from the viewpoint of peeling time and peeling sheet size, and is preferably 40 or less from the viewpoint of resolution, plating resistance, and etching resistance. m1 is more preferably 4-20, and even more preferably 6-12.

[0562] Specific examples of the ethylene glycol di(meth)acrylate compound represented by general formula (I) include tetraethylene glycol di(meth)acrylate with m1=4, nonaethylene glycol di(meth)acrylate with m1=9, or polyethylene glycol di(meth)acrylate with m1=14.

[0563] From the viewpoint of resolution and pore coverage, the (B) ethylenically unsaturated bond-containing compound preferably includes (b2) an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by general formula (II). B in general formula (II) may be -CH2CH2CH2- or -CH(CH3)CH2-.

[0564] The hydrogen atoms on the aromatic ring in the general formula (II) may be substituted with heteroatoms and / or substituents.

[0565] Examples of the heteroatom include a halogen atom, and examples of the substituent include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, a phenacyl group, an amino group, an alkylamino group having 1 to 10 carbon atoms, a dialkylamino group having 2 to 20 carbon atoms, a nitro group, a cyano group, a carbonyl group, a mercapto group, an alkylmercapto group having 1 to 10 carbon atoms, an aryl group, a hydroxyl group, a hydroxyalkyl group having 1 to 20 carbon atoms, a carboxyl group, a carboxyalkyl group having 1 to 10 carbon atoms in an alkyl group, an acyl group having 1 to 10 carbon atoms in an alkyl group, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, an alkylcarbonyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an N-alkylcarbamoyl group having 2 to 10 carbon atoms, a heterocyclic group, and an aryl group substituted with these substituents. These substituents may form a condensed ring, or hydrogen atoms in these substituents may be substituted with heteroatoms such as halogen atoms. When the aromatic ring in the general formula (II) has multiple substituents, the multiple substituents may be the same or different.

[0566] R3 and R4 in general formula (II) are independently a hydrogen atom or a methyl group. From the perspective of ensuring contrast of the photosensitive resin layer formed from the photosensitive resin composition immediately after exposure, it is preferred that one or both of R3 and R4 are hydrogen atoms, and it is more preferred that both of R3 and R4 are hydrogen atoms.

[0567] From the perspective of pore-blocking properties, it is preferred that a relatively long-chain alkylene oxide be added to the alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by general formula (II) (b2). More specifically, in general formula (II), n1, n2, n3, and n4 preferably satisfy the relationship n1+n2+n3+n4=4-50, more preferably n1+n2+n3+n4=10-50, further preferably n1+n2+n3+n4=20-50, and particularly preferably n1+n2+n3+n4=30-50.

[0568] From the viewpoint of pore-blocking properties, 40% or more by mass of the ethylenically unsaturated bond-containing compound (B) is preferably an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the general formula (II) (b2). More preferably, the alkylene oxide-modified bisphenol A di(meth)acrylate compound is one in which n1, n2, n3, and n4 in the general formula (II) satisfy the relationship n1+n2+n3+n4=30 to 50. More preferably, 50% by mass, further preferably 55% by mass or more, and most preferably 60% by mass of the ethylenically unsaturated bond-containing compound (B) is an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the general formula (II) (b2).

[0569] Preferred specific examples of the alkylene oxide-modified bisphenol A type di(meth)acrylate compound represented by general formula (II) (b2) include polyethylene glycol di(meth)acrylate obtained by adding an average of 1 unit of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 2 units of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 5 units of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 1 unit of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 2 units of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 1 unit ... di(meth)acrylate of polyethylene glycol with an average of 7 units of ethylene oxide added, di(meth)acrylate of polyalkylene glycol with an average of 6 units of ethylene oxide and an average of 2 units of propylene oxide added to both ends of bisphenol A, di(meth)acrylate of polyalkylene glycol with an average of 15 units of ethylene oxide added to both ends of bisphenol A, and di(meth)acrylate of polyalkylene glycol with an average of 15 units of ethylene oxide and an average of 2 units of propylene oxide added to both ends of bisphenol A.

[0570] In the general formula (II), from the perspective of resolution and water residual short-circuit fault suppression, n1, n2, n3 and n4 preferably satisfy the relationship n1+n2+n3+n4=2~10, and particularly preferably satisfy the relationship n1+n2+n3+n4=2~4.

[0571] From the perspective of taking into account both the porosity and the water residual short-circuit fault suppression properties, it is particularly preferred that the (B) olefinically unsaturated bond-containing compound simultaneously contains a compound satisfying n1+n2+n3+n4=30 to 50 in the general formula (II), a compound in which one or both of R3 and R4 in the general formula (II) are hydrogen atoms, and a compound satisfying n1+n2+n3+n4=2 to 10 in the general formula (II).

[0572] From the perspective of resolution and pore coverage, the ethylenically unsaturated bond-containing compound (B) preferably includes a tri(meth)acrylate compound (b3) represented by the general formula (III). X in the general formula (III) can be an alkylene group having 2 to 6 carbon atoms, such as -CH2CH2-, -CH2CH2CH2-, or -CH(CH3)CH2-.

[0573] From the viewpoint of pore blocking properties, the tri(meth)acrylate compound represented by the general formula (III) (b3) preferably has a relatively long-chain alkylene oxide moiety. More specifically, in the general formula (III), m2+m3+m4 is preferably 10-40, more preferably 20-40.

[0574] Preferred specific examples of the tri(meth)acrylate compound represented by the general formula (III) (b3) include ethylene oxide (EO)-modified trimethylolpropane tri(meth)acrylate (average EO addition mole number: 10 to 40), propylene oxide (PO)-modified trimethylolpropane tri(meth)acrylate (average PO addition mole number: 10 to 40), and the like.

[0575] From the viewpoint of pore-blocking properties, the (B) ethylenically unsaturated bond-containing compound preferably includes (b4) a urethane di(meth)acrylate compound represented by the general formula (IV).

[0576] In the general formula (IV), Z represents a divalent organic group, and examples thereof include an alkylene group having 1 to 10 carbon atoms, an alkylene oxide group having 2 to 10 carbon atoms, and a divalent alicyclic group having 3 to 10 carbon atoms which may have a substituent.

[0577] In the general formula (IV), Y represents an alkylene group having 2 to 6 carbon atoms, and examples thereof include -CH2CH2-, -CH2CH2CH2-, and -CH(CH3)CH2-.

[0578] From the viewpoint of further improving the hole-covering property, it is also preferred that -(YO) in the general formula (IV) s -partial and-(YO) t The - moieties are replaced independently of each other by -(C2H5O)-(C3H6O)9-.

[0579] As a preferred specific example of the urethane di(meth)acrylate compound represented by the general formula (IV) (b4), there can be cited the addition reaction products of a (meth)acrylic monomer having a hydroxyl group at the β position and a diisocyanate compound such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate and 1,6-hexamethylene diisocyanate, tris((meth)acryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di(meth)acrylate and EO, PO-modified urethane di(meth)acrylate. It should be noted that EO represents ethylene oxide, and the EO-modified compound has a block structure of ethylene oxide groups. In addition, PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide groups. As EO-modified urethane di(meth)acrylate, for example, the trade name "UA-11" manufactured by Shin-Nakamura Chemical Industry Co., Ltd. can be cited. Examples of EO and PO modified urethane di(meth)acrylates include "UA-13" manufactured by Shin-Nakamura Chemical Co., Ltd. These can be used alone or in combination of two or more.

[0580] (B) The ethylenically unsaturated bond-containing compound may contain an addition polymerizable monomer other than the components (b1) to (b4) as the component (b5).

[0581] As the component (b5), the following substances can be mentioned:

[0582] Tri(meth)acrylates other than component (b3), such as trimethylolpropane tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like;

[0583] Tetra(meth)acrylates, such as ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, pentaerythritol (poly)alkoxy tetra(meth)acrylate, etc.;

[0584] Penta(meth)acrylates, such as dipentaerythritol penta(meth)acrylate;

[0585] Hexa(meth)acrylates, such as dipentaerythritol hexa(meth)acrylate, hexa(meth)acrylate obtained by adding a total of 1 to 24 mol of ethylene oxide to the six terminals of dipentaerythritol, and hexa(meth)acrylate obtained by adding a total of 1 to 10 mol of ε-caprolactone to the six terminals of dipentaerythritol;

[0586] an acrylate compound having one (meth)acryloyl group;

[0587] Compounds obtained by reacting polyols with α,β-unsaturated carboxylic acids;

[0588] Compounds obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid; and

[0589] Phthalic acid compounds include, for example, γ-chloro-2-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate and β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate.

[0590] In the third embodiment, from the viewpoint of the hole-blocking property and adhesion of the resist pattern, the total content of all (B) ethylenically unsaturated bond-containing compounds in the photosensitive resin composition is preferably within a range of 1% by mass to 70% by mass, more preferably 2% by mass to 60% by mass, and even more preferably 4% by mass to 50% by mass.

[0591] (C) Photopolymerization initiator

[0592] (C) The photopolymerization initiator is a compound that polymerizes a monomer using light. The photosensitive resin composition contains a compound known in the art as a photopolymerization initiator.

[0593] The content of the photopolymerization initiator (C) in the photosensitive resin composition is preferably within the range of 0.01 to 20 mass%, more preferably 0.05 to 10 mass%, and even more preferably 0.1 to 7 mass%. The content of the photopolymerization initiator (C) is preferably 0.01 mass% or more from the viewpoint of obtaining sufficient sensitivity, and is preferably 20 mass% or less from the viewpoint of sufficient light transmission to the bottom surface of the resist and obtaining good high resolution.

[0594] (C) Photopolymerization initiators include quinones, aromatic ketones, acetophenones, acylphosphine oxides, benzoin or benzoin ethers, dialkyl ketals, thioxanthones, dialkylaminobenzoates, oxime esters, acridines, and further include hexaarylbiimidazoles, pyrazoline compounds, N-arylamino acids or ester compounds thereof (e.g., N-phenylglycine), and organic halogen compounds. These can be used alone or in combination of two or more. Among them, acridines are particularly suitable for direct imagewise exposure.

[0595] Examples of acridines include acridine, 9-phenylacridine, 1,6-bis(9-acridyl)hexane, 1,7-bis(9-acridyl)heptane, 1,8-bis(9-acridyl)octane, 1,9-bis(9-acridyl)nonane, 1,10-bis(9-acridyl)decane, 1,11-bis(9-acridyl)undecane, and 1,12-bis(9-acridyl)dodecane, and other acridine derivatives. From the perspective of suitability for direct imagewise exposure, the content of acridines in the photosensitive resin composition is preferably within a range of 0.1% to 5% by mass, more preferably 0.3% to 3% by mass, and even more preferably 0.5% to 2% by mass.

[0596] Examples of aromatic ketones include benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], 4,4'-bis(diethylamino)benzophenone, and 4-methoxy-4'-dimethylaminobenzophenone. These can be used alone or in combination of two or more. Among these, 4,4'-bis(diethylamino)benzophenone is preferred from the viewpoint of adhesion. Furthermore, from the viewpoint of transmittance, the content of aromatic ketones in the photosensitive resin composition is preferably within a range of 0.01% to 0.5% by mass, more preferably 0.02% to 0.3% by mass.

[0597] Examples of hexaarylbiimidazoles include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbiimidazole, 2-(o-chlorophenyl)-bis-4,5-(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-(2,4,6-trifluorophenyl)- phenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 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, and 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole. These can be used alone or in combination of two or more. 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer is preferred from the viewpoints of high sensitivity, resolution, and adhesion.

[0598] In the third embodiment, from the viewpoint of improving the peeling properties and / or sensitivity of the photosensitive resin layer, the content of the hexaarylbiimidazole compound in the photosensitive resin composition is preferably in the range of 0.05% by mass to 7% by mass, more preferably 0.1% by mass to 6% by mass, and even more preferably 1% by mass to 4% by mass.

[0599] Examples of N-aryl amino acids include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. Among these, N-phenylglycine is particularly preferred. From the perspective of improving release properties and / or sensitivity, the content of the N-aryl amino acid in the photosensitive resin composition is preferably 0.05% to 5% by mass, more preferably 0.1% to 2% by mass, relative to the total solids content of the photosensitive resin composition.

[0600] Examples of the organic halogen compound include amyl bromide, isopentyl bromide, isobutylene bromide, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and triazine chloride compounds. Among these, tribromomethylphenylsulfone is particularly preferred. From the perspective of improving release properties and / or sensitivity, the content of the organic halogen compound in the photosensitive resin composition is preferably 0.05% to 5% by mass, more preferably 0.1% to 3% by mass, relative to the total solids content of the photosensitive resin composition.

[0601] Examples of other photosensitizers include quinones such as 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone; benzoin ethers such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methylbenzoin, and ethylbenzoin; benzyldimethylketal, benzyldiethylketal; and oxime esters such as 1-phenyl-1,2-propanedione-2-O-benzoyloxime and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. From the viewpoint of improving release properties and / or sensitivity, the content of the photosensitizer in the photosensitive resin composition is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass, relative to the total solid content of the photosensitive resin composition.

[0602] In the third embodiment, the photosensitive resin composition also preferably contains a pyrazoline compound as a photosensitizer. Preferred pyrazoline compounds include 1-phenyl-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-pyrazoline, and 1-phenyl-3-(4-biphenylyl)-5-(4-tert-octyl-phenyl)-pyrazoline.

[0603] (D) Additives

[0604] The photosensitive resin composition may contain additives such as a color-changing agent, a dye, a plasticizer, an antioxidant, and a stabilizer as desired. For example, additives listed in Japanese Patent Application Laid-Open No. 2013-156369 and International Publication No. 2009 / 093706 may be used.

[0605] Examples of color-changing agents include leuco dyes and fluoran dyes. The use of a color-changing agent is preferred because the color of the exposed portion is visible. Furthermore, when an inspection machine or the like reads a registration mark used for exposure, a high contrast between the exposed and unexposed portions facilitates position identification, which is advantageous.

[0606] Examples of leuco dyes include tris(4-dimethylaminophenyl)methane [leuco crystal violet] and bis(4-dimethylaminophenyl)phenylmethane [leuco malachite green]. Leuco crystal violet is particularly preferred for good contrast. The leuco dye content in the photosensitive resin composition is preferably 0.1% to 10% by mass. To improve the contrast between the exposed and unexposed areas, the content is preferably 0.1% by mass or greater, and to maintain storage stability, it is preferably 10% by mass or less.

[0607] Examples of the basic dye include Basic Green 1 [CAS No. (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Malachite Green Oxalate [2437-29-8] (e.g., Aizen Malachite Green, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Brilliant Green [633-03-4], Magenta [632-99-5], Methyl Violet [603-47-4], Methyl Violet 2B [8004-87-3], Crystal Violet [548-62-9], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], etc. Among them, Basic Green 1, Malachite Green oxalate, and Basic Blue 7 are preferred, and Basic Green 1 is particularly preferred from the viewpoint of improving hue stability and exposure contrast.

[0608] In the third embodiment, the content of the basic dye in the photosensitive resin composition is preferably within a range of 0.001% by mass to 3% by mass, more preferably 0.01% by mass to 2% by mass, and even more preferably 0.01% by mass to 1% by mass. The dye content is preferably 0.001% by mass or greater to achieve good colorability, and is preferably 3% by mass or less to maintain the sensitivity of the photosensitive resin layer.

[0609] In the third embodiment, in order to suppress the delay in resist pattern peeling caused by the alkali-soluble polymer containing 10% to 24% by mass of (meth)acrylic acid structural units and shorten the peeling time, it is preferred that the photosensitive resin composition contain a toluenesulfonic acid amide such as o-toluenesulfonic acid amide or p-toluenesulfonic acid amide as a plasticizer. The content of the toluenesulfonic acid amide in the photosensitive resin composition is preferably within the range of 0.1% to 5% by mass, and more preferably within the range of 1% to 4% by mass.

[0610] Examples of other plasticizers include glycol esters such as polyethylene glycol, polypropylene glycol, polyoxypropylene polyoxyethylene ether, polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxypropylene monoethyl ether, and polyoxyethylene polyoxypropylene monoethyl ether; phthalate esters such as diethyl phthalate; tributyl citrate, triethyl citrate, acetyl triethyl citrate, acetyl tri-n-propyl citrate, and acetyl tri-n-butyl citrate; propylene glycol obtained by adding propylene oxide to both sides of bisphenol A; and ethylene glycol obtained by adding ethylene oxide to both sides of bisphenol A.

[0611] From the viewpoint of thermal stability or storage stability of the photosensitive resin composition, the photosensitive resin composition preferably contains at least one selected from the group consisting of the following substances as a stabilizer: a radical polymerization inhibitor such as 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), diphenylnitrosamine, triethylene glycol-bis(3-tert-butyl-5-methyl-4-hydroxyphenylpropane) esters), and nitrosophenylhydroxylamine aluminum salts; benzotriazoles, such as 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, 1-(2-di-n-octylaminomethyl)-benzotriazole, and bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole; carboxybenzotriazoles, such as 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, triazole, 6-carboxy-1,2,3-benzotriazole, a 1:1 mixture of 1-(2-di-n-butylaminomethyl)-5-carboxybenzotriazole and 1-(2-di-n-butylaminomethyl)-6-carboxybenzotriazole, N-(N,N-di-2-ethylhexyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-hydroxyethyl)aminomethylenecarboxybenzotriazole, and N-(N,N-di-2-ethylhexyl)aminoethylenecarboxybenzotriazole; and alkylene oxide compounds having a glycidyl group, such as neopentyl glycol diglycidyl ether (e.g., Kyoeisha Chemical Co., Ltd.), nineethylene glycol diglycidyl ether (for example, Epolight400E manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2 mol adduct diglycidyl ether (for example, Epolight3002 manufactured by Kyoeisha Chemical Co., Ltd.), hydrogenated bisphenol A diglycidyl ether (for example, Epolight4000 manufactured by Kyoeisha Chemical Co., Ltd.), 1,6-hexanediol diglycidyl ether (for example, Epolight1600 manufactured by Kyoeisha Chemical Co., Ltd.), etc.

[0612] In the third embodiment, the total content of all stabilizers in the photosensitive resin composition is preferably within a range of 0.001% by mass to 3% by mass, more preferably 0.01% by mass to 1% by mass, and even more preferably 0.05% by mass to 0.7% by mass. The total content of the stabilizers is preferably 0.001% by mass or more from the viewpoint of imparting good storage stability to the photosensitive resin composition, and is preferably 3% by mass or less from the viewpoint of maintaining the sensitivity of the photosensitive resin layer.

[0613] The additives described above can be used alone or in combination of two or more.

[0614] <Photosensitive resin composition preparation>

[0615] In the third embodiment, a photosensitive resin composition preparation can be formed by adding a solvent to the photosensitive resin composition. Suitable solvents include ketones such as acetone and methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropyl alcohol. The solvent is preferably added to the photosensitive resin composition such that the viscosity of the photosensitive resin composition preparation is 500 to 4000 mPa·s at 25°C.

[0616] <Photosensitive resin laminate>

[0617] In the third embodiment, a photosensitive resin laminate having a support and a photosensitive resin layer formed from the photosensitive resin composition and laminated on the support can be provided. The photosensitive resin laminate may also have a protective layer on the side of the photosensitive resin layer opposite to the support side, if desired.

[0618] The support is not particularly limited, but preferably is a transparent support that transmits light emitted from the exposure light source. Examples of such supports include polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film, polyacrylonitrile film, styrene copolymer film, polyamide film, and cellulose derivative film. These films can also be stretched as needed. The haze is preferably 0.01% to 5.0%, more preferably 0.01% to 2.5%, and even more preferably 0.01% to 1.0%. Regarding the thickness of the film, thinner films are more advantageous in terms of image formation and economic efficiency, but since strength must be maintained, a thickness of 10 μm to 30 μm is preferred.

[0619] Another important characteristic of the protective layer used in a photosensitive resin laminate is that its adhesion to the photosensitive resin layer is relatively low compared to the adhesion between the support and the photosensitive resin layer, allowing for easy peeling. Preferred examples of the protective layer include polyethylene films and polypropylene films. For example, films with excellent peelability described in Japanese Patent Application Laid-Open No. 59-202457 can be used. The thickness of the protective layer is preferably 10 to 100 μm, more preferably 10 to 50 μm.

[0620] In the third embodiment, the thickness of the photosensitive resin layer in the photosensitive resin laminate is preferably 5 μm to 100 μm, more preferably 7 μm to 60 μm. A smaller thickness of the photosensitive resin layer improves the resolution of the resist pattern, while a larger thickness of the photosensitive resin layer improves the strength of the cured film. Therefore, the thickness can be selected according to the intended use.

[0621] As a method for producing a photosensitive resin laminate by sequentially laminating a support, a photosensitive resin layer, and, if desired, a protective layer, a known method can be used.

[0622] For example, a liquid photosensitive resin composition is prepared, then coated onto a support using a bar coater or a roll coater and dried to laminate a photosensitive resin layer formed from the liquid photosensitive resin composition onto the support. Furthermore, a protective layer may be laminated on the photosensitive resin layer as desired to produce a photosensitive resin laminate.

[0623] <Resist Pattern Formation Method>

[0624] The method for forming a resist pattern preferably includes, in order: a lamination step of laminating a photosensitive resin layer formed from the photosensitive resin composition on a support, an exposure step of exposing the photosensitive resin layer, and a development step of developing the exposed photosensitive resin layer. In the third embodiment, an example of a specific method for forming a resist pattern is shown below.

[0625] First, in the lamination process, a photosensitive resin layer is formed on a substrate using a laminator. Specifically, if the photosensitive resin laminate has a protective layer, the protective layer is removed and then the photosensitive resin layer is heated and pressed onto the substrate surface using a laminator for lamination. Examples of substrate materials include copper, stainless steel (SUS), glass, and indium tin oxide (ITO).

[0626] In the third embodiment, the photosensitive resin layer can be laminated only on one side of the substrate surface, or on both sides as needed. The heating temperature during lamination is generally 40°C to 160°C. In addition, by performing heat and pressure bonding during lamination two or more times, the adhesion of the resulting resist pattern to the substrate can be improved. During heat and pressure bonding, a two-stage laminator with two rollers can be used, or the laminate of the substrate and the photosensitive resin layer can be repeatedly passed through rollers for pressure bonding.

[0627] Next, in the exposure process, an exposure machine is used to expose the photosensitive resin layer to active light. Exposure can be performed after peeling off the support as desired. When exposure is performed through a photomask, the exposure amount is determined by the illuminance of the light source and the exposure time, and can be measured using a light meter. In the exposure process, direct imaging exposure can also be performed. In direct imaging exposure, exposure is performed on the substrate using a direct drawing device without using a photomask. As a light source, a semiconductor laser or an ultra-high pressure mercury lamp with a wavelength of 350nm to 410nm is used. When the drawing pattern is controlled by a computer, the exposure amount is determined by the illuminance of the exposure light source and the moving speed of the substrate.

[0628] Next, in the development step, a developing device is used to remove the unexposed or exposed areas of the photosensitive resin layer using a developer. After exposure, any support on the photosensitive resin layer is removed. Next, a developer comprising an aqueous alkaline solution is used to remove the unexposed or exposed areas, thereby forming a resist image.

[0629] The aqueous alkaline solution is preferably an aqueous solution of Na2CO3, K2CO3, or the like. The aqueous alkaline solution is selected based on the characteristics of the photosensitive resin layer; typically, a Na2CO3 aqueous solution with a concentration of 0.2% to 2% by mass is used. The aqueous alkaline solution may also contain a surfactant, a defoaming agent, or a small amount of an organic solvent to promote development. The developer temperature during the development step is preferably maintained constant within the range of 20°C to 40°C.

[0630] A resist pattern can be obtained through the above steps. If desired, a heating step at 100°C to 300°C can be further performed. This heating step can improve the chemical resistance of the resist pattern. A heating furnace utilizing hot air, infrared rays, or far-infrared rays can be used for the heating step.

[0631] The photosensitive resin composition of the third embodiment can be suitably used to form a circuit of a printed circuit board. Generally, as a method for forming a circuit of a printed circuit board, a subtractive method and a semi-additive method (SAP) are used.

[0632] The subtractive method is a method of forming a circuit by removing only non-circuit portions from a conductor arranged on the entire surface of a substrate by etching.

[0633] SAP is a method in which a resist is formed on the non-circuit portion of a conductive seed layer disposed on the entire surface of a substrate, and then only the circuit portion is formed by plating.

[0634] <Method for Manufacturing Conductive Pattern>

[0635] The method for manufacturing a conductor pattern preferably includes, in sequence: a lamination step of laminating a photosensitive resin layer formed by the above-mentioned photosensitive resin composition on a substrate such as a metal plate or a metal film insulating plate; an exposure step of exposing the photosensitive resin layer; a development step of removing the unexposed portion or the exposed portion of the exposed photosensitive resin layer with a developer to obtain a substrate having an anti-etching pattern; and a conductor pattern forming step of etching or plating the substrate having the anti-etching pattern.

[0636] In the third embodiment, the method for manufacturing a conductive pattern is as follows: a metal plate or a metal film insulating plate is used as a substrate, a resist pattern is formed by the above-mentioned resist pattern forming method, and then a conductive pattern forming step is performed. In the conductive pattern forming step, a conductive pattern is formed on the substrate surface (e.g., copper surface) exposed by development using a known etching method or plating method.

[0637] Furthermore, the third embodiment is suitable for the following applications, for example.

[0638] <Circuit Board Manufacturing Method>

[0639] After the conductive pattern is produced by the conductive pattern production method, a stripping step is further performed to strip the resist pattern from the substrate using an aqueous solution having a stronger alkalinity than the developer, thereby obtaining a circuit board (eg, a printed circuit board) having a desired wiring pattern.

[0640] The alkaline aqueous solution used for stripping (hereinafter referred to as the "stripping solution") is not particularly limited, but a 2% to 5% by mass aqueous solution of NaOH or KOH, 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 water-soluble solvents include alcohols. The temperature of the stripping solution during the stripping step is preferably within the range of 40°C to 70°C.

[0641] Lead Frame Manufacturing

[0642] A metal plate such as copper, a copper alloy, or an iron alloy is used as a substrate. A resist pattern is formed using a resist pattern forming method. Then, a lead frame can be manufactured through the following steps. First, the substrate exposed by development is etched to form a conductor pattern. Then, a stripping step is performed to remove the resist pattern using the same method as circuit board manufacturing, resulting in the desired lead frame.

[0643] <Manufacturing of a substrate having a concavo-convex pattern>

[0644] The resist pattern formed by the resist pattern forming method can be used as a protective mask member when a substrate is processed by a sandblasting method. In this case, as a substrate, for example, glass, silicon wafer, amorphous silicon, polycrystalline silicon, ceramics, sapphire, metal materials, etc. can be listed. The resist pattern is formed on these substrates by the same method as the resist pattern forming method. Then, a sandblasting process is performed in which a spray material is blown from above the formed resist pattern to cut to a target depth, and a stripping process is performed in which the resist pattern portion remaining on the substrate is removed from the substrate with an alkaline stripping solution, etc., thereby manufacturing a base material having a fine concave-convex pattern on the substrate.

[0645] In the sandblasting process, a known blasting material can be used. For example, fine particles with a particle size of 2 μm to 100 μm made of SiC, SiO 2 , Al 2 O 3 , CaCO 3 , ZrO, glass, stainless steel, etc. are generally used.

[0646] Semiconductor Package Manufacturing

[0647] A wafer, having already been fabricated into a large-scale integrated circuit (LSI) circuit, is used as a substrate. After forming a resist pattern on the wafer using a resist patterning method, the following steps are performed to manufacture a semiconductor package. First, a conductor pattern is formed by applying columnar plating of copper, solder, or other materials to the openings exposed by development. Next, a stripping step is performed to remove the resist pattern using the same method used in the circuit board manufacturing process. Furthermore, etching is performed to remove the thin metal layer outside the columnar plating, resulting in the desired semiconductor package.

[0648] In this third embodiment, the photosensitive resin composition can be used for the manufacture of printed circuit boards; manufacture of lead frames for mounting IC chips; precision processing of metal foils such as metal mask manufacturing; manufacture of packages such as ball grid arrays (BGA) and chip size packages (CSP); manufacture of tape substrates such as chip on film (COF) and tape automated bonding (TAB); manufacture of semiconductor bumps; and manufacture of partition walls for flat panel displays such as ITO electrodes, address electrodes, and electromagnetic wave shielding.

[0649] It should be noted that the values ​​of the above parameters were measured according to the measurement methods in the examples described later unless otherwise specified.

[0650] <Fourth embodiment>

[0651] Hereinafter, a mode for implementing a fourth embodiment of the present invention (hereinafter simply referred to as “this fourth embodiment”) will be described in detail.

[0652] <Photosensitive resin composition>

[0653] In the fourth embodiment, the photosensitive resin composition contains (A) an alkali-soluble polymer, (B) an ethylenically unsaturated bond-containing compound, and (C) a photopolymerization initiator. Optionally, the photosensitive resin composition may further contain other components such as (D) a stabilizer.

[0654] In this specification, “(meth)acrylic acid” refers to acrylic acid or methacrylic acid, “(meth)acryloyl” refers to acryloyl or methacryloyl, and “(meth)acrylate” refers to “acrylate” or “methacrylate”.

[0655] [(A) Alkali-soluble polymer]

[0656] From the viewpoint of prolongation of resolution and minimum developing time, aforementioned (A) alkali soluble polymer comprises the first copolymer of the containing ratio of acid monomer unit less than 25 mass % and the containing ratio of aromatic monomer unit being more than 30 mass %.The first copolymer can also comprise other monomer units on the basis of acid monomer unit and aromatic monomer unit according to expectation.The dispersity of the copolymer represented by the ratio of weight average molecular weight (described later) of copolymer and number average molecular weight is preferably more than 1 and less than 6.

[0657] Examples of the acid monomer include (meth)acrylic acid, pentenoic acid, unsaturated dicarboxylic anhydride, and hydroxystyrene. Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, itaconic anhydride, fumaric acid, and citraconic anhydride. Among them, (meth)acrylic acid is preferred.

[0658] The copolymerization ratio of the acid monomer units in the component (A) is preferably less than 25% by mass, more preferably 10% to 24% by mass, and even more preferably 15% to 23% by mass, relative to the total mass of all monomer units. A content of the acid monomer units within this range is preferred from the perspectives of improving resolution and extending the minimum development time.

[0659] Aromatic monomers are also called unsaturated aromatic compounds. Examples of aromatic monomers include styrene, α-methylstyrene, and vinylnaphthalene; and aralkyl (meth)acrylates. Examples of aralkyl (meth)acrylates include benzyl (meth)acrylate.

[0660] The copolymerization ratio of the aromatic monomer units (preferably styrene units) in the component (A) is preferably 30% by mass or more, more preferably 32% to 60% by mass, and even more preferably 35% to 55% by mass, relative to the total mass of all monomer units. Setting the copolymerization ratio of the aromatic monomer, which is highly hydrophobic and poorly compatible with the developer and development rinse water, within the above range is preferred from the viewpoints of improving resolution and extending the minimum development time.

[0661] Examples of other monomers include alkyl (meth)acrylates, conjugated diene compounds, polar monomers, and crosslinking monomers.

[0662] The term "alkyl (meth)acrylate" is a concept encompassing both chain alkyl esters and cyclic alkyl esters. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate.

[0663] Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene.

[0664] Examples of polar monomers include:

[0665] Hydroxyl-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and pentenol; amino-containing monomers such as 2-aminoethyl methacrylate;

[0666] (Meth) acrylamide, N-hydroxymethyl (meth) acrylamide and other amide-containing monomers;

[0667] Acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-cyanoethyl acrylate and other cyano group-containing monomers;

[0668] Epoxy-containing monomers such as glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate;

[0669] wait.

[0670] Examples of the crosslinkable monomer include trimethylolpropane triacrylate and divinylbenzene.

[0671] The first copolymer is particularly preferably a copolymer of (meth)acrylic acid, styrene, and other monomers.

[0672] In the fourth embodiment, a second copolymer containing the aforementioned aromatic monomer units at a content of 45% to 90% by mass is also preferred from the perspectives of resolution, developability, and agglomeration. A 45% by mass content of the aromatic monomer units in the second copolymer tends to ensure the hydrophobicity of the resist pattern containing the second copolymer. Furthermore, a weight ratio of the second copolymer of 25% or more relative to the total weight of the copolymers is preferred for improved agglomeration.

[0673] The second copolymer may also contain the acid monomer units and other monomer units described above. As the aromatic monomer for polymerizing the second copolymer, styrene is preferred from the viewpoint of hydrophobicity. From the viewpoint of developability, the upper limit of the content of the aromatic monomer units in the second copolymer is more preferably 80% by mass or 70% by mass.

[0674] The second copolymer may contain the acid monomer units described above and other monomer units. From the perspectives of resolution, developability, and agglomerability, the content of the acid monomer units described above is preferably 25% to 50% by mass, more preferably 25% to 40% by mass. As the acid monomer used to polymerize the second copolymer, (meth)acrylic acid is preferred from the perspective of developability.

[0675] The weight average molecular weight of the component (A) (when the component (A) comprises a plurality of copolymers, the weight average molecular weight of the entire mixture) is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 15,000 to 100,000. Adjusting the weight average molecular weight of the component (A) within this range is preferred from the viewpoint of adapting the development time during resist pattern formation to the operating conditions of the line used.

[0676] In the fourth embodiment, the content of component (A) in the photosensitive resin composition is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 40% to 60% by mass, based on the total solid content of the photosensitive resin composition (hereinafter, unless otherwise specified, the same shall apply to each component). This content is preferably 10% by mass or more from the viewpoint of maintaining alkali developability, and is preferably 90% by mass or less from the viewpoint of fully exhibiting the performance of the resist pattern formed by exposure.

[0677] The first copolymer containing less than 25% by mass of the acid monomer unit and 30% by mass or more of the aromatic monomer unit is preferably 5% to 50% by mass, more preferably 10% to 40% by mass, based on the total solid content of the photosensitive resin composition.

[0678] [(B) Compound containing an ethylenically unsaturated bond]

[0679] (B) The ethylenically unsaturated bond-containing compound is a compound having polymerizability by having an ethylenically unsaturated group in its structure. From the viewpoint of addition polymerizability, the ethylenically unsaturated bond is preferably a terminal ethylenically unsaturated group.

[0680] In the fourth embodiment, when (A) an alkali-soluble polymer and (B) an ethylenically unsaturated bond-containing compound are used in combination, the weight average molecular weight of the (B) ethylenically unsaturated bond-containing compound is preferably 900 or less from the viewpoint of ensuring good resolution of the resist pattern and extending the minimum development time. In this specification, the average molecular weight of the (B) ethylenically unsaturated bond-containing compound means the weight average molecular weight derived from the structural formula of the single ethylenically unsaturated bond-containing compound when the (B) ethylenically unsaturated bond-containing compound is a single compound, and means the weighted average of the weight average molecular weights of the individual ethylenically unsaturated bond-containing compounds and the blending ratio when the (B) ethylenically unsaturated bond-containing compound is composed of multiple compounds.

[0681] The weight average molecular weight of the ethylenically unsaturated bond-containing compound (B) is preferably 850 or less, and even more preferably 800 or less, from the viewpoint of improving resolution and extending the minimum development time. Furthermore, from the viewpoint of suppressing edge fusion of the photosensitive resin laminate, it is preferably 50 or more, and even more preferably 100 or more. Here, edge fusion refers to a phenomenon in which the photosensitive resin composition layer oozes out from the end surface of the roll when the photosensitive resin laminate is wound into a roll.

[0682] (B) The ethylenically unsaturated bond-containing compound may include at least one selected from the group consisting of the following (b1) to (b6):

[0683] (b1) an ethylene glycol di(meth)acrylate compound represented by the following general formula (I):

[0684]

[0685] {wherein, R1 and R2 independently represent a hydrogen atom or a methyl group, and m1 is a number satisfying 2 to 40.};

[0686] (b2) an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the following general formula (II):

[0687]

[0688] {wherein, R3 and R4 independently represent a hydrogen atom or a methyl group, A is C2H4, B is C3H6, n1, n2, n3, and n4 are integers satisfying the relationship n1+n2+n3+n4=2 to 50, and the arrangement of the repeating units of -(AO)- and -(BO)- may be random or block. In the case of block arrangement, either -(AO)- or -(BO)- may be on the side of the biphenyl group.};

[0689] (b3) a tri(meth)acrylate compound represented by the following general formula (III):

[0690]

[0691] {wherein, R5 to R7 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3, and m4 independently represent integers of 0 to 40, m2+m3+m4 is 0 to 40, and when m2+m3+m4 is 2 or more, multiple Xs may be the same or different};

[0692] (b4) a urethane di(meth)acrylate compound represented by the following general formula (IV):

[0693]

[0694] {wherein, R8 and R9 independently represent a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 6 carbon atoms, Z represents a divalent organic group, and s and t independently represent integers of 0 to 40, and s+t≥1};

[0695] (b5) a tetra(meth)acrylate compound represented by the following general formula (XI):

[0696]

[0697] {wherein, R5 to R8 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3, m4, and m5 independently represent integers of 0 to 40, m2+m3+m4+m5 is 0 to 50, and when m2+m3+m4+m5 is 2 or more, multiple Xs may be the same or different}; and

[0698] (b6) Addition polymerizable monomers other than the above-mentioned (b1) to (b5).

[0699] From the viewpoint of adjusting the peeling time of the resist pattern and the size of the peelable sheet, the (B) ethylenically unsaturated bond-containing compound preferably includes (b1) an ethylene glycol di(meth)acrylate compound represented by the general formula (I).

[0700] In general formula (I), m1 is preferably 2 or more from the viewpoint of peeling time and peeling sheet size, and is preferably 40 or less from the viewpoint of resolution, plating resistance, and etching resistance. m1 is more preferably 4-20, and even more preferably 6-12.

[0701] Specific examples of the ethylene glycol di(meth)acrylate compound represented by general formula (I) include tetraethylene glycol di(meth)acrylate with m1=4, nonaethylene glycol di(meth)acrylate with m1=9, or polyethylene glycol di(meth)acrylate with m1=14.

[0702] From the perspective of suppressing the formation of aggregates during development of a photosensitive resin layer formed from the photosensitive resin composition, the ethylenically unsaturated bond-containing compound (B) preferably includes an alkylene oxide-modified bisphenol A di(meth)acrylate compound (b2) represented by general formula (II). B in general formula (II) may be -CH2CH2CH2- or -CH(CH3)CH2-.

[0703] The hydrogen atoms on the aromatic ring in the general formula (II) may be substituted with heteroatoms and / or substituents.

[0704] Examples of heteroatoms include halogen atoms, and examples of substituents include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, aryl groups having 6 to 18 carbon atoms, phenacyl groups, amino groups, alkylamino groups having 1 to 10 carbon atoms, dialkylamino groups having 2 to 20 carbon atoms, nitro groups, cyano groups, carbonyl groups, mercapto groups, alkylmercapto groups having 1 to 10 carbon atoms, aryl groups, hydroxyl groups, hydroxyalkyl groups having 1 to 20 carbon atoms, carboxyl groups, carboxylalkyl groups having 1 to 10 carbon atoms, acyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, alkoxycarbonyl groups having 1 to 20 carbon atoms, alkylcarbonyl groups having 2 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, N-alkylcarbamoyl groups having 2 to 10 carbon atoms, heterocyclic groups, and aryl groups substituted with these substituents. These substituents may form a condensed ring, or hydrogen atoms in these substituents may be substituted with heteroatoms such as halogen atoms. When the aromatic ring in the general formula (II) has a plurality of substituents, the plurality of substituents may be the same or different.

[0705] R3 and R4 in general formula (II) are independently a hydrogen atom or a methyl group. From the perspective of ensuring contrast of the photosensitive resin layer formed from the photosensitive resin composition immediately after exposure, it is preferred that one or both of R3 and R4 are hydrogen atoms, and it is more preferred that both of R3 and R4 are hydrogen atoms.

[0706] From the perspective of improving resolution and extending the minimum development time, it is preferred that a relatively short-chain alkylene oxide be added to the alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by general formula (II) (b2). More specifically, in general formula (II), n1, n2, n3, and n4 preferably satisfy the relationship n1+n2+n3+n4=0-30, more preferably n1+n2+n3+n4=0-25, further preferably n1+n2+n3+n4=0-20, and particularly preferably n1+n2+n3+n4=0-10.

[0707] From the viewpoint of improving resolution and extending the minimum development time, 40% by mass or more of the ethylenically unsaturated bond-containing compound (B) is preferably an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the general formula (II) (b2), and more preferably an alkylene oxide-modified bisphenol A di(meth)acrylate compound wherein n1, n2, n3, and n4 in the general formula (II) satisfy the relationship n1+n2+n3+n4=0 to 20. More preferably, 50% by mass, further preferably 55% by mass or more, and most preferably 60% by mass of the ethylenically unsaturated bond-containing compound (B) is an alkylene oxide-modified bisphenol A di(meth)acrylate compound represented by the general formula (II) (b2).

[0708] Preferred specific examples of the alkylene oxide-modified bisphenol A type di(meth)acrylate compound represented by general formula (II) (b2) include polyethylene glycol di(meth)acrylate obtained by adding an average of 1 unit of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 2 units of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 5 units of ethylene oxide to each of the two ends of bisphenol A, polyethylene glycol di(meth)acrylate obtained by adding an average of 1 unit ... Polyethylene glycol di(meth)acrylate with an average of 7 units of ethylene oxide, polyalkylene glycol di(meth)acrylate with an average of 6 units of ethylene oxide and an average of 2 units of propylene oxide added to both ends of bisphenol A, polyalkylene glycol di(meth)acrylate with an average of 15 units of ethylene oxide added to both ends of bisphenol A, polyalkylene glycol di(meth)acrylate with an average of 15 units of ethylene oxide and an average of 2 units of propylene oxide added to both ends of bisphenol A, etc.

[0709] In the general formula (II), from the viewpoint of improving resolution, n1, n2, n3 and n4 preferably satisfy the relationship of n1+n2+n3+n4=2-20, and particularly preferably satisfy the relationship of n1+n2+n3+n4=2-10.

[0710] From the viewpoint of improving the resolution and extending the minimum development time, it is particularly preferred that (B) the compound containing an ethylenically unsaturated bond simultaneously contains: a compound satisfying n1+n2+n3+n4=2 to 20 in the general formula (II), a compound in which one or both of R3 and R4 in the general formula (II) are methyl groups, and a compound satisfying n1+n2+n3+n4=2 to 16 in the general formula (II).

[0711] From the perspective of suppressing the formation of aggregates during development of a photosensitive resin layer formed from the photosensitive resin composition, the (B) ethylenically unsaturated bond-containing compound preferably includes (b3) a tri(meth)acrylate compound represented by the general formula (III). X in the general formula (III) is an alkylene group having 2 to 6 carbon atoms, for example, -CH2CH2-, -CH2CH2CH2-, or -CH(CH3)CH2-.

[0712] From the viewpoint of resolution, the tri(meth)acrylate compound represented by the general formula (III) (b3) preferably has a relatively short-chain alkylene oxide moiety. More specifically, in the general formula (III), m2+m3+m4 is preferably 8-40, more preferably 9-25.

[0713] Preferred specific examples of the tri(meth)acrylate compound represented by the general formula (III) (b3) include ethylene oxide (EO)-modified trimethylolpropane tri(meth)acrylate (average EO addition mole number: 1 to 40), propylene oxide (PO)-modified trimethylolpropane tri(meth)acrylate (average PO addition mole number: 1 to 40), and the like.

[0714] From the viewpoint of resolution, the (B) ethylenically unsaturated bond-containing compound preferably includes (b4) a urethane di(meth)acrylate compound represented by the general formula (IV).

[0715] In the general formula (IV), Z represents a divalent organic group, and examples thereof include an alkylene group having 1 to 10 carbon atoms, an alkylene oxide group having 2 to 10 carbon atoms, and a divalent alicyclic group having 3 to 10 carbon atoms which may have a substituent.

[0716] In the general formula (IV), Y represents an alkylene group having 2 to 6 carbon atoms, and examples thereof include -CH2CH2-, -CH2CH2CH2-, and -CH(CH3)CH2-.

[0717] From the viewpoint of further improving the resolution, it is also preferred that -(YO) in the general formula (IV) s -partial and-(YO) t The - moieties are replaced independently of each other by -(C2H5O)-(C3H6O)9-.

[0718] As a preferred specific example of the urethane di(meth)acrylate compound represented by the general formula (IV) (b4), there can be cited the addition reaction products of a (meth)acrylic monomer having a hydroxyl group at the β position and a diisocyanate compound such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate and 1,6-hexamethylene diisocyanate, tris((meth)acryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di(meth)acrylate and EO, PO-modified urethane di(meth)acrylate. It should be noted that EO represents ethylene oxide, and the EO-modified compound has a block structure of ethylene oxide groups. In addition, PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide groups. As EO-modified urethane di(meth)acrylate, for example, the trade name "UA-11" manufactured by Shin-Nakamura Chemical Industry Co., Ltd. can be cited. Examples of EO and PO modified urethane di(meth)acrylates include "UA-13" manufactured by Shin-Nakamura Chemical Co., Ltd. These can be used alone or in combination of two or more.

[0719] From the viewpoint of suppressing the generation of aggregates during development of the photosensitive resin layer formed from the photosensitive resin composition, the (B) ethylenically unsaturated bond-containing compound preferably includes (b5) a tetra(meth)acrylate compound represented by the general formula (XI).

[0720] X in the general formula (XI) is an alkylene group having 2 to 6 carbon atoms, for example, -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, etc.

[0721] Preferred specific examples of the tetra(meth)acrylate compound represented by the general formula (XI) (b5) include pentaerythritol tetra(meth)acrylate and pentaerythritol (poly)alkoxy tetra(meth)acrylate.

[0722] (B) The ethylenically unsaturated bond-containing compound may contain an addition polymerizable monomer other than the components (b1) to (b5) as the component (b6).

[0723] Component (b6) includes the following:

[0724] Tri(meth)acrylates other than component (b3), such as trimethylolpropane tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like;

[0725] Tetra(meth)acrylates other than component (b5), such as ditrimethylolpropane tetra(meth)acrylate and dipentaerythritol tetra(meth)acrylate; penta(meth)acrylates, such as dipentaerythritol penta(meth)acrylate;

[0726] Hexa(meth)acrylates, such as dipentaerythritol hexa(meth)acrylate, hexa(meth)acrylate obtained by adding a total of 1 to 24 mol of ethylene oxide to the six terminals of dipentaerythritol, and hexa(meth)acrylate obtained by adding a total of 1 to 10 mol of ε-caprolactone to the six terminals of dipentaerythritol;

[0727] an acrylate compound having one (meth)acryloyl group;

[0728] Compounds obtained by reacting polyols with α,β-unsaturated carboxylic acids;

[0729] Compounds obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid; and

[0730] Phthalic acid compounds include, for example, γ-chloro-2-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate and β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate.

[0731] In the fourth embodiment, from the viewpoint of edge fusion and adhesion of the photosensitive resin laminate, the total content of all (B) ethylenically unsaturated bond-containing compounds in the photosensitive resin composition is preferably in the range of 1% by mass to 70% by mass, more preferably 2% by mass to 60% by mass, and even more preferably 4% by mass to 50% by mass.

[0732] [(C) Photopolymerization initiator]

[0733] The component (C) generates radicals capable of initiating polymerization of the component (B) upon irradiation with light.

[0734] Examples of the component (C) include aromatic ketone compounds, quinone compounds, benzoin ether compounds, benzoin compounds, benzyl compounds, hexaarylbiimidazole compounds, and acridine compounds. Among these, from the perspectives of high resolution and good pore coverage, it is preferred to use one or more selected from hexaarylbiimidazole compounds and acridine compounds. Furthermore, from the perspective of the sensitivity of the photosensitive resin composition, the component (C) preferably includes an acridine compound.

[0735] Examples of the hexaarylbiimidazole compound include 2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylimidazolyl dimer, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylimidazolyl dimer, 2,4,5-tris-(o-chlorophenyl)-diphenylimidazolyl dimer, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-imidazolyl dimer, 2,2',5-bis-(2-fluorophenyl)-4, 4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer imidazolyl dimer, 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,4,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer , 2,2'-bis-(2,4,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-imidazolyl dimer, etc.

[0736] In addition, examples of the acridinium compound include:

[0737] Acridine, 9-phenylacridine, 1,6-bis(9-acridinyl)hexane, 1,7-bis(9-acridinyl)heptane, 1,8-bis(9-acridinyl)octane, 1,9-bis(9-acridinyl)nonane, 1,10-bis(9-acridinyl)decane, 1,11-bis(9-acridinyl)undecane, 1,12-bis(9-acridinyl)dodecane, etc.

[0738] The content of component (C) in the photosensitive resin composition of the fourth embodiment is preferably 0.1% to 2% by mass, more preferably 0.2% to 1.8% by mass, further preferably 0.3% to 1.7% by mass, and particularly preferably 0.4% to 1.6% by mass. Setting the content of component (C) within this range is preferred from the viewpoint of obtaining good sensitivity and peeling properties.

[0739] From the viewpoint of improving sensitivity and resolution, the component (C) may further contain a sensitizer. Examples of such a sensitizer include N-arylamino acids, organic halogen compounds, and other sensitizers.

[0740] Examples of the N-aryl amino acids include:

[0741] N-phenylglycine, N-methyl-N-phenylglycine, N-ethyl-N-phenylglycine, etc.;

[0742] Examples of the organic halogen compound include:

[0743] Pentyl bromide, isopentyl bromide, isobutylene bromide, vinyl bromide, diphenylmethyl bromide, benzyl bromide, dibromomethane, tribromomethylphenyl sulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, chlorinated triazine compounds, etc.

[0744] Examples of the other sensitizers include:

[0745] Quinone compounds such as 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone;

[0746] Aromatic ketone compounds such as benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4,4'-bis(diethylamino)benzophenone;

[0747] Benzoin ether compounds such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, and ethyl benzoin;

[0748] Benzil dimethyl ketal, benzil diethyl ketal, 1-phenyl-1,2-propanedione-2-O-benzoyl oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime and other oxime ester compounds;

[0749] wait.

[0750] From the viewpoint of the sensitivity of the composition and the releasability of the cured resist film, the content of the sensitizer in the fourth embodiment is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably 0.1 to 2% by mass.

[0751] It should be noted that in the photosensitive resin composition of the fourth embodiment, an acridine compound and an N-aryl amino acid are used as the (C) component. When they are used in combination within the above-mentioned usage ratio range, it is preferred from the perspective of suppressing the etching rate when forming a conductor pattern and suppressing the vertical and horizontal differences in wiring width.

[0752] [(D) Stabilizer]

[0753] The photosensitive resin composition may contain a stabilizer as desired. In the fourth embodiment, from the perspective of improving resolution, hindered phenol is preferably used as a stabilizer. Generally, hindered phenol refers to a phenol with large steric hindrance. The photosensitive resin composition contains a compound represented by the following general formula (V) as a hindered phenol:

[0754]

[0755] {where R 51 represents an optionally substituted straight-chain alkyl group, a branched-chain alkyl group, an aryl group, a cyclohexyl group, a straight-chain alkyl group sandwiched by a divalent linking group, a branched-chain alkyl group sandwiched by a divalent linking group, a cyclohexyl group sandwiched by a divalent linking group, or an aryl group sandwiched by a divalent linking group, and R 52 、R 53 and R 54 Each independently represents hydrogen, or an optionally substituted straight-chain alkyl group, a branched-chain alkyl group, an aryl group, a cyclohexyl group, a straight-chain alkyl group sandwiched by a divalent linking group, a branched-chain alkyl group sandwiched by a divalent linking group, a cyclohexyl group sandwiched by a divalent linking group, or an aryl group sandwiched by a divalent linking group.

[0756] The compound represented by general formula (V) is excellent in terms of improving the resolution of photosensitive resin compositions and suppressing the decrease in sensitivity of photosensitive resin compositions. It should be noted that the compound represented by general formula (V) does not have two or more phenolic hydroxyl groups on a single aromatic ring and has a substituent at only one of the two ortho positions to the phenolic hydroxyl group, which is characterized by controlling the steric hindrance around the phenolic hydroxyl group. It is believed that this structure contributes to the aforementioned excellent performance.

[0757] From the viewpoint of improving the resolution of the photosensitive resin composition and suppressing the decrease in sensitivity of the photosensitive resin composition, the compound represented by general formula (V) is preferably one in which R 51 、R 52 、R 53 and R 54 At least one of them has an aromatic ring. From the same viewpoint, the hydroxyl concentration of the hindered phenol is preferably 0.10 mol / 100 g to 0.75 mol / 100 g. In addition, from the same viewpoint, it is preferred that in the above general formula (V), R 51 、R 52 、R 53 and R 54 At least one of the groups is a linear or branched alkyl group, or an aryl group sandwiched by a divalent linking group, and preferred alkyl groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, and the like, and preferred divalent linking groups include, for example, a thioether group, a substituted or unsubstituted alkylene group, and the like, and the aryl group may be substituted by a hydroxyl group or an alkyl group.

[0758] From the same viewpoint, the compound represented by the general formula (V) is preferably, for example, a compound represented by the following general formula (VI), a compound represented by the following general formula (VIII), a compound represented by the following general formula (IX), or a compound represented by the following general formula (X):

[0759]

[0760] {where R 55 represents the general formula (VII), and R 56 、R 57 and R 58 Each independently represents hydrogen or the following general formula (VII):

[0761]

[0762] [Where R 59 and R 60 Each independently represents hydrogen or an optionally substituted linear alkyl group, branched alkyl group, aryl group, or cyclohexyl group. ]},

[0763]

[0764] {where R 61 and R 64 independently represent a linear or branched alkyl group, and R 62 、R 63 、R 65 and R 66 Each independently represents hydrogen, or a linear or branched alkyl group, X 1 Represents a divalent linking group.

[0765]

[0766] {where R 67 、R 70 and R 73 independently represent a linear or branched alkyl group, and R 68 、R 69 、R 71 、R 72 、R 74 and R 75 independently represent hydrogen, or a linear or branched alkyl group, Y 1 Represents a trivalent linking group.

[0767]

[0768] {where R 76 、R 79 、R 82 and R 85 independently represent a linear or branched alkyl group, and R 77 、R 78 、R 80 、R 81 、R 83 、R 84 、R 86 and R 87 Z independently represents hydrogen, or a linear or branched alkyl group, 1 represents a tetravalent linking group.}. Moreover, as X in the above general formula (VIII) 1 , a thioether group, a substituted or unsubstituted alkylene group, etc. can be mentioned.

[0769] From the perspective of improving the resolution of the photosensitive resin composition and suppressing a decrease in sensitivity of the photosensitive resin composition, the compound represented by general formula (V) preferably has a molecular weight of about 130 to about 1000, more preferably about 200 to about 800, even more preferably about 300 to about 500, and most preferably about 300 to about 400. Furthermore, it is preferred that the compound have a specific gravity of about 1.02 to about 1.12 or a melting point of about 155°C or higher (e.g., about 208°C or higher); be sparingly soluble in water but readily soluble in organic solvents such as methanol, acetone, and toluene; or be in the form of a solid (e.g., powder, crystals, etc.) or liquid when used.

[0770] Examples of the compound represented by general formula (V) include 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), styrenated phenol (manufactured by Kawaguchi Chemical Industry Co., Ltd., ANTAGESP), tribenzylphenol (manufactured by Kawaguchi Chemical Industry Co., Ltd., TBP, a phenol having 1 to 3 benzyl groups). Among these, 4,4'-thiobis(6-tert-butyl-m-cresol) and 4,4'-butylenebis(3-methyl-6-tert-butylphenol) are preferred from the viewpoint of improving resolution and suppressing a decrease in sensitivity of the photosensitive resin composition due to the large content of the compound represented by general formula (I).

[0771] The proportion of the compound represented by the general formula (V) relative to the total mass of the photosensitive resin composition is 0.001% by mass to 10% by mass. From the perspective of improving resolution, this proportion is 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and most preferably 0.7% by mass or more. On the other hand, from the perspective of minimizing sensitivity reduction and improving resolution, this proportion is 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and particularly preferably 1.5% by mass or less.

[0772] In the fourth embodiment, as the hindered phenol, a compound other than the compound represented by the general formula (V) may be further contained. Examples of the compound other than the compound represented by the general formula (V) include 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-amylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), bis(2-hydroxy-3-tert-butyl-5-ethylphenyl)methane, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis[3-(3,5-di-tert-butyl-5-ethylphenyl)propionate], and the like. butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamic acid), 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, etc.

[0773] In the fourth embodiment, the total content of all hindered phenols in the photosensitive resin composition is preferably 0.001% by mass to 10% by mass relative to the total mass of the photosensitive resin composition.

[0774] In the fourth embodiment, the photosensitive resin composition may also contain a stabilizer other than hindered phenols. As a stabilizer other than hindered phenols, it is preferable to contain at least one selected from the group consisting of the following substances: a free radical polymerization inhibitor, such as 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), diphenylnitrosamine, triethylene glycol-bis(3-tert-butyl-5-methyl-4-hydroxyphenylpropionate), and nitrosophenylhydroxylamine aluminum salt; benzophenone Triazoles, such as 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, 1-(2-di-n-octylaminomethyl)-benzotriazole, and bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole; carboxybenzotriazoles, such as 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, 6-carboxy-1,2,3 -benzotriazole, a 1:1 mixture of 1-(2-di-n-butylaminomethyl)-5-carboxybenzotriazole and 1-(2-di-n-butylaminomethyl)-6-carboxybenzotriazole, N-(N,N-di-2-ethylhexyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-hydroxyethyl)aminomethylenecarboxybenzotriazole, and N-(N,N-di-2-ethylhexyl)aminoethylenecarboxybenzotriazole; and an alkylene oxide compound having a glycidyl group, such as neopentyl glycol diglycidyl ether (for example, manufactured by Kyoeisha Chemical Co., Ltd. Epolight1500NP), nonaethylene glycol diglycidyl ether (for example, Epolight400E manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2 mol adduct diglycidyl ether (for example, Epolight3002 manufactured by Kyoeisha Chemical Co., Ltd.), hydrogenated bisphenol A diglycidyl ether (for example, Epolight4000 manufactured by Kyoeisha Chemical Co., Ltd.), 1,6-hexanediol diglycidyl ether (for example, Epolight1600 manufactured by Kyoeisha Chemical Co., Ltd.), etc.

[0775] In the fourth embodiment, the total content of all stabilizers in the photosensitive resin composition is preferably within a range of 0.001% by mass to 3% by mass, more preferably 0.01% by mass to 1% by mass, and even more preferably 0.05% by mass to 0.7% by mass. The total content of the stabilizers is preferably 0.001% by mass or more from the viewpoint of imparting good storage stability to the photosensitive resin composition, and is preferably 3% by mass or less from the viewpoint of maintaining the sensitivity of the photosensitive resin layer.

[0776] [Other ingredients]

[0777] The photosensitive resin composition of the fourth embodiment may contain other components in addition to the above-described components (A) to (D). Examples of such other components include leuco dyes, basic dyes, plasticizers, antioxidants, radical polymerization inhibitors, and solvents.

[0778] [Leuco dye]

[0779] The leuco dye can be blended into the photosensitive resin composition of the fourth embodiment in order to impart suitable color development and excellent peeling properties to the resist cured film.

[0780] Specific examples of leuco dyes include leuco crystal violet (tris[4-(dimethylamino)phenyl]methane), 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-dimethylaminofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl fluoran, 2-(2-chloroanilino)-6-dibutylaminofluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluoran, 1,2-benzo-6-diethylaminofluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-ethylisopentylaminofluoran, 2-methyl-6-(N-p-toluene-N-ethylamino)fluoran, 2-(N-phenyl-N-methylamino)-6-(N-p-toluene-N-ethylamino)fluoran, 2-(3'-trifluoromethylanilino)-6-diethylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 3-methoxy-4-dodecyloxyphenylquinoline, etc. Among them, leuco crystal violet is preferred.

[0781] The content of the leuco dye in the photosensitive resin composition of the fourth embodiment is preferably 0.6% to 1.6% by mass, more preferably 0.7% to 1.2% by mass. By setting the usage ratio of the leuco dye within this range, good color development and good releasability can be achieved.

[0782] [Basic dyes]

[0783] Examples of the basic dye include Basic Green 1 [CAS No. (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Malachite Green Oxalate [2437-29-8] (e.g., Aizen Malachite Green, trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Brilliant Green [633-03-4], Magenta [632-99-5], Methyl Violet [603-47-4], Methyl Violet 2B [8004-87-3], Crystal Violet [548-62-9], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], Diamond Green, etc. Among them, at least one selected from Basic Green 1, Malachite Green oxalate, Basic Blue 7, and Diamond Green is preferred. Basic Green 1 is particularly preferred from the viewpoint of hue stability and exposure contrast.

[0784] The content of the basic dye in the photosensitive resin composition of the fourth embodiment is preferably 0.001% to 3% by mass, more preferably 0.01% to 2% by mass, and even more preferably 0.01% to 1.2% by mass. By adopting the usage ratio within this range, both good color development and high sensitivity can be achieved.

[0785] [Solvent]

[0786] The photosensitive resin composition of the fourth embodiment may be a mixture of the above-mentioned components (A) to (C) and other optional components, or may be used as a photosensitive resin composition prepared by adding an appropriate solvent to these components.

[0787] Examples of the solvent used here include ketone compounds such as methyl ethyl ketone (MEK); alcohols such as ethanol, ethanol, and isopropyl alcohol; and the like.

[0788] The solvent is preferably used in such a proportion that the viscosity of the photosensitive resin composition prepared liquid at 25° C. is 500 to 4000 mPa·s.

[0789] <Photosensitive element>

[0790] In the fourth embodiment, the photosensitive element is a laminate (photosensitive resin laminate) in which a photosensitive resin layer formed from the above-mentioned photosensitive resin composition is laminated on a support. If necessary, a protective layer may be provided on the surface of the photosensitive resin layer opposite to the support.

[0791] [Support]

[0792] The support is preferably a transparent substrate that transmits light emitted from the exposure light source. Examples of such a support include polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. As needed, stretched films may also be used as these films.

[0793] The haze of the support is preferably 5 or less.

[0794] A thinner support is advantageous in terms of image forming properties and economic efficiency, but strength must be maintained. Considering both, a support with a thickness of 10 μm to 30 μm can be preferably used.

[0795] [Photosensitive resin layer]

[0796] When the photosensitive resin composition used for forming the photosensitive resin layer contains a solvent, the solvent may remain in the photosensitive resin layer, but it is preferred that the solvent is removed.

[0797] The thickness of the photosensitive resin layer is preferably 5 μm to 100 μm, more preferably 7 μm to 60 μm. Thinner thicknesses improve resolution, while thicker thicknesses increase film strength. Therefore, the thickness of the composition layer can be appropriately adjusted within the above range depending on the intended use.

[0798] [Protective layer]

[0799] An important characteristic of the protective layer is that its adhesion to the photosensitive resin layer is sufficiently weaker than the adhesion between the support and the photosensitive resin layer, allowing for easy peeling. Preferred examples of protective layers include polyethylene films and polypropylene films. Furthermore, films with excellent peelability, such as those disclosed in Japanese Patent Application Laid-Open No. 59-202457, can be used.

[0800] The thickness of the protective layer is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm.

[0801] [Method for manufacturing photosensitive element]

[0802] The photosensitive element can be produced by sequentially laminating a support, a photosensitive resin layer, and, if necessary, a protective layer. A known method can be employed for laminating the support, the photosensitive resin layer, and the protective layer.

[0803] For example, a photosensitive resin composition is prepared as the aforementioned photosensitive resin composition liquid, which is first coated onto a support using a bar coater or a roll coater and dried to form a photosensitive resin layer formed of the photosensitive resin composition on the support. Subsequently, a protective layer is laminated on the formed photosensitive resin layer, as needed, to produce a photosensitive element.

[0804] <Method for Forming Resist Pattern>

[0805] A resist pattern can be formed on a substrate using the above-mentioned photosensitive element.

[0806] The method for forming a resist pattern preferably includes the following steps in sequence:

[0807] a lamination step of laminating a photosensitive resin layer of a photosensitive element on a conductive substrate;

[0808] an exposure step of exposing the stacked photosensitive resin layers to light; and

[0809] A developing step of developing the exposed photosensitive resin layer.

[0810] In the method for forming a resist pattern according to the fourth embodiment, first, in a lamination step, a photosensitive resin layer is formed on a substrate using a laminator. Specifically, if the photosensitive element has a protective layer, after removing the protective layer, the photosensitive resin layer is laminated to the substrate surface using a laminator by heat and pressure bonding.

[0811] As the substrate, a metal plate or an insulating substrate having a metal film is used. Examples of the metal material include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). These substrates may also have through holes for coping with multilayer substrates.

[0812] Here, the photosensitive resin layer may be laminated only on one side of the substrate surface, or may be laminated on both sides of the substrate as needed. The heating temperature at this time is preferably set to 40°C to 160°C. From the viewpoint of further improving the adhesion of the obtained resist pattern to the substrate, it is preferred to perform heat pressing two or more times. When performing pressing two or more times, a two-stage laminator with two rollers can be used, or the laminate of the substrate and the photosensitive resin layer can be repeatedly passed through the rollers for pressing.

[0813] Furthermore, during the lamination process, the photosensitive resin layer of the photosensitive element can be laminated onto the conductive substrate with a wetting agent interposed therebetween. This is a preferred lamination method from the perspective of improving followability and yield. The wetting agent preferably includes at least one selected from pure water, deionized water, and electrolyzed water, and a copper chelating agent (e.g., at least one selected from the group consisting of imidazole compounds, triazole compounds, pyridine compounds, and pyrazole compounds).

[0814] Next, in the exposure step, the photosensitive resin layer is exposed using an exposure machine. This exposure may be performed through the support without peeling the support, or after peeling the support as needed.

[0815] By performing this exposure in a patterned manner, after the development step described later, a resist film (resist pattern) having a desired pattern can be obtained. Patterned exposure can be performed by either a method of exposing through a photomask or a method of maskless exposure. When exposing through a photomask, the exposure amount is determined by the light source illumination and the exposure time. The exposure amount can be measured using a light meter.

[0816] Maskless exposure involves direct exposure of the substrate using a drawing device without the use of a photomask. Light sources include semiconductor lasers with a wavelength of 350nm to 410nm and ultra-high-pressure mercury lamps. The pattern is controlled by a computer, and the exposure dose is determined by the illumination of the exposure light source and the substrate's travel speed.

[0817] Next, in the development step, the exposed photosensitive resin layer is developed. For example, unexposed portions of the photosensitive resin layer are removed using a developer. If a support is present on the photosensitive resin layer after exposure, this is preferably removed before the development step.

[0818] In the development step, a developer comprising an alkaline aqueous solution is used to remove the unexposed areas, thereby forming a resist image. The alkaline aqueous solution is preferably an aqueous solution of NaCO or KCO, for example. The alkaline aqueous solution is selected based on the characteristics of the photosensitive resin layer, but a NaCO aqueous solution with a concentration of 0.2% to 2% by mass is preferably used. This alkaline aqueous solution may also contain a surfactant, defoaming agent, or a small amount of an organic solvent to promote development.

[0819] The temperature of the developer in the development step is preferably maintained constant within a range of 20°C to 40°C.

[0820] The resist pattern is obtained through the above steps. Depending on the situation, a heating step at 100°C to 300°C may be further performed. This heating step is suitable from the perspective of further improving chemical resistance. Heating can be performed using a heating furnace using a suitable method such as hot air, infrared light, or far infrared light.

[0821] <Circuit Board Formation Method>

[0822] The method for forming a circuit board of the fourth embodiment preferably includes the following steps in sequence:

[0823] a lamination step of laminating a photosensitive resin layer of a photosensitive element on a conductive substrate;

[0824] an exposure step of exposing the stacked photosensitive resin layer to light;

[0825] a developing step of developing the exposed photosensitive resin layer;

[0826] a conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed by development; and

[0827] A stripping step of stripping the resist pattern.

[0828] In the conductor pattern forming step, a conductor pattern can be formed on the substrate having the resist pattern formed thereon, using a known etching method or plating method, on the substrate surface (eg, copper surface) exposed by the development step.

[0829] In the stripping step, the substrate with the conductive pattern formed thereon is brought into contact with an appropriate stripping liquid to remove the resist pattern. This step results in the desired circuit board being obtained.

[0830] The stripping solution used in the stripping step is preferably an alkaline aqueous solution. For example, a 2% to 5% by mass aqueous NaOH solution or a 2% to 5% by mass aqueous KOH solution is preferably used as the alkaline aqueous solution. A small amount of a water-soluble solvent, such as an alcohol, may be added to the stripping solution. The temperature of the stripping solution in the stripping step is preferably 40°C to 70°C.

[0831] The photosensitive resin composition, photosensitive element, resist pattern forming method, and circuit board manufacturing method of the fourth embodiment can be extremely suitably used in manufacturing, for example, printed wiring boards, lead frames, substrates having concavo-convex patterns, semiconductor packages, and the like.

[0832] It should be noted that the measurement methods of the above-mentioned various parameters were measured according to the measurement methods in the examples described later unless otherwise specified.

[0833] Example

[0834] <Examples and Comparative Examples According to the First Embodiment>

[0835] Hereinafter, the photosensitive resin composition according to the first embodiment will be specifically described using examples.

[0836] (1) Determination of physical properties of raw materials

[0837] <Measurement of weight average molecular weight>

[0838] The weight-average molecular weight of the polymer was determined as a polystyrene-equivalent value using a gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 model, columns: four Shodex (registered trademark) (KF-807, KF-806M, KF-806M, KF-802.5) manufactured by Showa Denko K.K. connected in series, mobile phase solvent: tetrahydrofuran, using a calibration curve obtained from a polystyrene standard sample (Shodex STANDARD SM-105 manufactured by Showa Denko K.K.).

[0839] <Acid equivalent>

[0840] In this specification, acid equivalent refers to the mass (g) of a polymer having one equivalent of carboxyl groups in the molecule. Acid equivalent was measured by potentiometric titration using a 0.1 mol / L sodium hydroxide aqueous solution using a Hiranuma automatic titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.

[0841] (2) Preparation and analysis of evaluation samples

[0842] <Production of Photosensitive Elements>

[0843] The components shown in Table 1 and the following components were mixed, and methyl ethyl ketone (MEK) was further added to prepare a photosensitive resin composition having a solid content concentration of 53% by mass.

[0844] As a coloring substance, 0.04 parts by mass of diamond green;

[0845] As a leuco dye, 0.6 parts by mass of leuco crystal violet;

[0846] As a halogen compound, 0.7 parts by mass of tribromomethylphenyl sulfone;

[0847] As a plasticizer, 2 parts by mass of p-toluenesulfonamide;

[0848] As benzotriazole, 0.05 parts by mass of carboxybenzotriazole;

[0849] As benzotriazoles, 0.15 parts by mass of 1-(2-di-n-octylaminomethyl)-benzotriazole;

[0850] As an antioxidant, 0.05 parts by mass of hydrogenated bisphenol A diglycidyl ether (Kyoeisha Chemical, Epolight 4000); and

[0851] As a radical polymerization inhibitor, 0.004 parts by mass of tris(nitrosophenylhydroxylamine)aluminum was used.

[0852] The numbers in the columns of each component in Table 1 are the amounts (parts by mass) of the components used in the preparation of the composition.

[0853] The obtained photosensitive resin composition was uniformly coated on a 16 μm thick polyethylene terephthalate film (R310 manufactured by Mitsubishi Plastics Corporation, haze value 2.1%) serving as a support using a bar coater, and then heated and dried in a dryer controlled at 95°C for 2.5 minutes to form a 25 μm thick photosensitive resin composition layer on the support.

[0854] Next, a 19 μm-thick polyethylene film (GF-18 manufactured by Tamapoly Co., Ltd.) was attached as a protective layer to the surface of the photosensitive resin composition layer opposite to the support, thereby obtaining a photosensitive element.

[0855] <Substrates used in evaluation>

[0856] As a substrate for hole-covering property evaluation, a substrate having 1008 through-holes with a diameter of 6 mm formed on a 1.6 mm thick copper-clad laminated substrate on which a 35 μm thick copper foil was laminated was used;

[0857] As a substrate for evaluation other than the hole-covering property, a copper-clad laminate substrate having a thickness of 0.4 mm and on which a copper foil having a thickness of 18 μm was laminated was used.

[0858] The substrate for evaluation of the cover porosity was subjected to surface conditioning by surface treatment using a jet sander and then subjected to evaluation.

[0859] Substrates for evaluation other than the porosity were subjected to surface conditioning by sequentially performing surface treatment using a soft etchant (CPE-900, manufactured by Ryoe Chemical Co., Ltd.) and surface cleaning with a 10 mass % H 2 SO 4 aqueous solution.

[0860] <Lamination>

[0861] On the surface-conditioned substrate, while peeling off the polyethylene film of the photosensitive element obtained in each Example or Comparative Example, lamination was performed using a hot roll laminator (AL-70, manufactured by Asahi Kasei Corporation) at a roll temperature of 105° C., an air pressure of 0.35 MPa, and a lamination speed of 1.5 m / min.

[0862] <Exposure>

[0863] Exposure was performed by a direct writing exposure method using a direct writing exposure apparatus (manufactured by Orbotech Ltd., Paragon Ultra 200, dominant wavelength 355 nm).

[0864] The exposure pattern will be described later in the section on each evaluation item.

[0865] <Development>

[0866] After peeling the support from the exposed photosensitive resin composition layer, an alkali developer (manufactured by Fuji Kikou Co., Ltd., dry film developer) was used to spray a 1% by mass aqueous solution of NaCO at 30°C for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin composition layer. After development, the substrate was rinsed with pure water for 1.5 times the development time, dehydrated with an air knife, and then dried with warm air to obtain a substrate having a cured film for evaluation.

[0867] The minimum development time is the minimum time required until the unexposed portion of the photosensitive resin composition layer is completely dissolved and removed.

[0868] <Evaluation of sensitivity>

[0869] For the evaluation of sensitivity, a laminated substrate was used after 15 minutes had passed from the above-mentioned <Lamination>.

[0870] The laminated substrate was exposed to direct drawing using a mask pattern of 10 lines with a line / space of 40 μm / 40 μm, and then developed by the method described in <Development>. The resist top width of the resulting resist pattern was measured using an optical microscope, and the sensitivity was evaluated according to the following criteria.

[0871] Exposure dose to reach 39.0 μm in resist top width is 28 mJ or less: Sensitivity "○ (good)"

[0872] Exposure dose exceeding 28 mJ for resist top width up to 39.0 μm: Sensitivity "× (poor)"

[0873] Here, the resist line was measured at the fifth line from the end of the 10 lines, approximately 5 mm from the end in the longitudinal direction, and the average value of three measurements was used as the measurement value. The line width differs between the edge and center of the pattern due to the influence of the diffusion of the developer and rinse water, and the resist line tends to become thinner at the edge.

[0874] As described in the above-mentioned <Evaluation of Sensitivity>, the exposure amount in the following evaluation items was an exposure amount at which the resist top width reached 39.0 μm for a mask pattern of line / space=40 μm / 40 μm.

[0875] <Resolution Evaluation>

[0876] The evaluation of resolution was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[0877] This laminated substrate was exposed to direct drawing in a line / space = 1 / 1 pattern of various sizes, and then developed by the method described in the above <Development>.

[0878] The obtained pattern was observed with an optical microscope to determine the minimum pattern width formed, and the resolution was evaluated based on the following criteria.

[0879] When the minimum pattern width is 20 μm or less: Resolution "○ (good)"

[0880] When the minimum pattern width exceeds 20 μm and is less than 24 μm: Resolution "△ (OK)"

[0881] When the minimum pattern width exceeds 24 μm: Resolution "× (poor)"

[0882] <Adhesion>

[0883] Evaluation of adhesion was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[0884] This laminated substrate was exposed to direct drawing with patterns of independent lines of various sizes, and then developed by the method described in the above <Development>.

[0885] The obtained pattern was observed with an optical microscope, and the adhesiveness was evaluated according to the following criteria.

[0886] When the minimum pattern width formed normally is 18 μm or less: Adhesion “○ (good)”

[0887] When the minimum pattern width formed normally exceeds 18 μm and is 22 μm or less: Adhesion "△ (acceptable)"

[0888] The minimum pattern width formed normally exceeds 22 μm: Adhesion "× (poor)"

[0889] Here, the case where the line pattern is not formed normally refers to a case where the line pattern collapses, a case where the line pattern meanders, or a case where the line pattern does not exist on the substrate.

[0890] <Pore-covering properties>

[0891] The evaluation of the hole-covering property was performed by observing the laminated substrate after the above-mentioned <Lamination> obtained using the substrate having through-holes.

[0892] The number of holes formed on the through-holes by the photosensitive resin composition layer (capping film) being broken was measured, and the ratio to all holes (capping film breakage rate) was calculated and evaluated according to the following criteria.

[0893] When the rupture rate of the hole-covering film is less than 0.1%: the hole-covering property is "◎ (very good)"

[0894] When the hole-covering film rupture rate is 0.1% or more and less than 2%: hole-covering property "○ (good)"

[0895] When the rupture rate of the cover film is 2% or more: Covering performance "× (poor)"

[0896] Etching speed (wiring bottom width)

[0897] Evaluation of the etching rate (wiring bottom width) was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[0898] The laminated substrate was exposed directly using a pattern of 10 lines with a line / space ratio of 50 μm / 30 μm. After 15 minutes from exposure, the support was peeled from the photosensitive resin composition layer. Using an alkali developer (manufactured by Fuji Kikou Co., Ltd., a dry film developer), a 1% by mass aqueous solution of NaCO at 30°C was sprayed for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin composition layer. After development, the substrate was rinsed with pure water for 1.5 times the development time.

[0899] Next, the washed substrate having the line / space pattern was introduced into a cupric chloride etching apparatus (NLE-2000, manufactured by Tokyo Kakoki Co., Ltd.) without drying, with the lines / spaces of the substrate oriented orthogonally to the transport direction (MD). Etching was performed for 55 seconds at a line speed of 2.0 m / min under the conditions of a hydrochloric acid concentration of 3.2 mol / L, a cupric chloride concentration of 2.0 mol / L, an etching spray pressure of 0.2 MPa, and an etching solution temperature of 50°C.

[0900] After the etching, the cured film on the substrate was peeled off at 50° C. using a 3.0 mass % NaOH aqueous solution as a stripping solution. The bottom width of the copper wire wiring pattern in the MD direction was measured using an optical microscope.

[0901] Here, the measurement position of the wiring pattern lines was set at the fifth line from the end of the 10 lines, approximately 5 mm from the end in the longitudinal direction, and the average value of three measurements was used as the measurement value. The diffusion of developer and rinse water affects the resist differently at the ends and the center of the pattern, resulting in different final wiring line widths, with the wiring width tending to be thinner at the ends.

[0902] <Vertical and horizontal differences in wiring width>

[0903] The evaluation of the vertical and horizontal differences in the wiring width was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[0904] The laminated substrate was subjected to direct drawing exposure using an exposure pattern in which 10 lines with a line / space of 50 μm / 30 μm were arranged in a tiled pattern in the MD and TD directions.

[0905] After 15 minutes from the start of exposure, the support was peeled off from the photosensitive resin composition layer. Using an alkali developer (manufactured by Fujikikou Co., Ltd., a dry film developer), a 1% by mass aqueous solution of NaCO at 30°C was sprayed for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin composition layer. After development, the film was rinsed with pure water for 1.5 times the development time.

[0906] Next, the washed substrate having the line / space pattern was introduced into a cupric chloride vacuum etching apparatus (manufactured by FUJI KIKOU CO., LTD., with an inlet width of 750 mm and a tank length of 2.6 m) without drying, with the lines / spaces of the substrate oriented orthogonally to the conveyance direction (MD). Etching was performed at a linear speed of 2.2 m / min for 71 seconds, with 14 rows of etching liquid pipes in the MD direction (with a pipe interval of approximately 18 cm), 14 spray nozzles per pipe in the TD direction (slit nozzles, the spray direction was parallel to the TD direction, the nozzle interval was approximately 14 cm, and the distance from the substrate was approximately 5 cm), and without vibration, under the conditions of a hydrochloric acid concentration of 2.85 mol / L, a cupric chloride concentration of 2.0 mol / L, an etching spray pressure of 0.3 MPa, a vacuum pressure of 0.15 MPa, and an etching liquid temperature of 48°C.

[0907] After the etching, the cured film on the substrate was peeled off at 50° C. using a 3.0 mass % NaOH aqueous solution as a stripping solution to obtain two sets of copper line patterns in the MD and TD directions. The bottom widths of the patterns were measured using an optical microscope.

[0908] Here, the measurement position of the wiring pattern lines was set at the fifth line from the end of the 10 lines, approximately 5 mm from the end in the longitudinal direction, and the average of three measurements was used as the measurement value. The diffusion of developer and rinse water affects the resist differently at the ends and the center of the pattern, resulting in different final wiring line widths, with the wiring width tending to be thinner at the ends.

[0909] Furthermore, the vertical and horizontal differences in wiring width were calculated using the following formula and evaluated based on the following criteria.

[0910] Width difference between vertical and horizontal lines (μm) = TD-MD

[0911] When the vertical and horizontal difference of the wiring width is 1 μm or less: Vertical and horizontal difference of the wiring bottom width "◎ (very good)"

[0912] When the vertical and horizontal difference of the wiring width exceeds 1 μm and is 2 μm or less: Vertical and horizontal difference of the wiring bottom width "○ (good)"

[0913] When the vertical and horizontal difference of the wiring width exceeds 2μm and is less than 4μm: The vertical and horizontal difference of the wiring bottom width is "△ (OK)"

[0914] When the vertical and horizontal difference of the wiring width exceeds 4μm: Vertical and horizontal difference of the wiring bottom width "× (bad)"

[0915] Examples 1 to 23 and Comparative Examples 1 to 8

[0916] The compositions of the photosensitive resin compositions used in Examples and Comparative Examples are shown in Table 1.

[0917] The details of the component names described in Table 1 are shown in Table 2. The compounding amounts of the components in Table 1 are all parts by mass in terms of solid content.

[0918] Table 1 also shows the evaluation results obtained using the respective compositions.

[0919]

[0920] Table 2. Ingredient Details (1 of 2)

[0921]

[0922]

[0923] (Table 2 is not complete)

[0924] Table 2. Ingredient Details (2 of 2)

[0925]

[0926] <Examples and Comparative Examples According to the Second Embodiment>

[0927] Hereinafter, the photosensitive resin composition according to the second embodiment will be specifically described using examples.

[0928] (1) Determination of physical properties of raw materials

[0929] <Acid equivalent>

[0930] Acid equivalent refers to the mass of an alkali-soluble polymer having one equivalent of carboxyl groups therein. Acid equivalent is determined by potentiometric titration using an automatic titrator (e.g., Hiranuma Automatic Titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.) using a 0.1 mol / L aqueous sodium hydroxide solution.

[0931] <Measurement of weight average molecular weight>

[0932] The weight-average molecular weight of the polymer was determined as a polystyrene-equivalent value using a gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 model, columns: four Shodex (registered trademark) (KF-807, KF-806M, KF-806M, KF-802.5) manufactured by Showa Denko K.K. connected in series, mobile phase solvent: tetrahydrofuran, using a calibration curve obtained from a polystyrene standard sample (Shodex STANDARD SM-105 manufactured by Showa Denko K.K.).

[0933] (2) Method for preparing evaluation samples

[0934] <Production of Photosensitive Elements>

[0935] The components shown in Table 3 were mixed, and methyl ethyl ketone (MEK) was further added to prepare a photosensitive resin composition having a solid content concentration of 55% by mass.

[0936] The obtained photosensitive resin composition was uniformly applied onto a 16 μm thick polyethylene terephthalate film (GR-16, manufactured by Teijin DuPont Films Ltd.) as a support using a bar coater, and then heated and dried in a dryer controlled at 95° C. for 4 minutes to form a 33 μm thick photosensitive resin layer on the support.

[0937] Next, a polyethylene film (GF-18 manufactured by Tamapoly Co., Ltd.) having a thickness of 19 μm was attached as a protective layer to the surface of the photosensitive resin layer opposite to the support, thereby obtaining a photosensitive element.

[0938] <Substrates used in evaluation>

[0939] As an evaluation substrate, a 1.6 mm thick copper-clad laminate laminated with a 35 μm rolled copper foil was used, the surface of which was polished and conditioned by wet polishing roll grinding. Polishing was performed twice using Scotch (registered trademark) HD#600 manufactured by 3M.

[0940] <Lamination>

[0941] On a substrate that had been surface-conditioned and preheated to 60°C, the polyethylene film of the photosensitive element obtained in each Example or Comparative Example was peeled off and laminated using a hot roll laminator (AL-70, manufactured by Asahi Kasei Corporation) at a roll temperature of 105°C, an air pressure of 0.35 MPa, and a lamination speed of 1.5 m / min.

[0942] <Exposure>

[0943] A direct drawing exposure machine (manufactured by Hitachi Via Mechanics Co., Ltd., DE-1DH, light source: GaN blue-violet diode, main wavelength 405±5nm) was used, and a Stouffer 41-step stepper or a prescribed DI exposure mask pattern was used at an illumination of 80mW / cm 2 Under these conditions, exposure was performed with an exposure equivalent to 14 stops on the Stouffer 41-stop step exposure chart.

[0944] <Development>

[0945] After peeling the support from the exposed photosensitive resin layer, an alkali developer (manufactured by Fuji Kikou Co., Ltd., dry film developer) was used to spray a 1% by mass aqueous solution of NaCO at 30°C for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin layer. After development, the substrate was rinsed with pure water for 1.5 times the development time, dehydrated with an air knife, and then dried with warm air to obtain a substrate having a cured film for evaluation.

[0946] The minimum development time refers to the minimum time required until the unexposed portion of the photosensitive resin layer is completely dissolved and removed.

[0947] <Etching>

[0948] For the evaluation substrate having a resist pattern formed by development, a copper chloride etching apparatus (manufactured by Tokyo Kakoki Co., Ltd., copper chloride etching apparatus) was used to spray a 50°C copper chloride etching solution (copper chloride concentration of 250 g / L, HCl concentration of 3 mol / L) for 60 seconds to dissolve and remove the copper foil in the portion not covered by the resist pattern on the copper-clad laminate.

[0949] <Peeling>

[0950] The evaluation substrate after etching was sprayed with a 3% by mass sodium hydroxide aqueous solution heated to 50° C. to remove the cured resist.

[0951] (3) Evaluation method

[0952] (i) Visual aggregation test

[0953] The thickness of the photopolymerizable resin laminate is 50 μm and the area is 0.6 m 2The photosensitive layer (resist layer) is dissolved in 200 ml of 1% by mass Na2CO3 aqueous solution and sprayed for 3 hours using a circulating spray device at a spray pressure of 0.1 MPa. Then, the developer is left for 1 day to observe the generation of aggregates. When a large amount of aggregates are generated, powdery or oily substances are observed at the bottom and sides of the spray device. In addition, aggregates sometimes float in the developer. A developer with a good aggregation property will not generate such aggregates at all, or even if it is generated, it is a very small amount and can be easily washed off by washing with water. The generation state of aggregates is visually observed and graded as follows.

[0954] ◎ (remarkably good): No aggregates were generated.

[0955] ○ (good): There were no aggregates on the bottom or sides of the spray device, and a very small amount of aggregates were visually observed floating in the developer, but were easily washed off by water.

[0956] △ (OK): Aggregates are floating on the bottom or side of the spray device and in the developer. Even with water washing, all the aggregates cannot be washed away.

[0957] × (poor): Aggregates were observed throughout the spray device and were floating in the developer. Even with water washing, not all of the aggregates were washed away, and most of them remained.

[0958] (ii) Sensitivity test

[0959] The photosensitive elements obtained in the examples and comparative examples were laminated and exposed by the above method. The exposure dose (mJ / cm2) equivalent to 14 steps on the Stouffer 41-step exposure meter was investigated based on the exposure dose and the number of steps remaining after development. 2 , 14 / 41ST exposure), and evaluated according to the following criteria.

[0960] Sensitivity "0" (good): 14 / 41ST exposure 25mJ / cm 2 The following situations

[0961] Sensitivity "×" (poor): 14 / 41ST exposure exceeds 25mJ / cm 2 Situation

[0962] (iii) Resolution test

[0963] The photosensitive elements obtained in the examples and comparative examples were laminated as described above, and 15 minutes later, the samples obtained were used to perform direct drawing exposure with a line / space ratio of 1 / 1. Development was then performed as described above.

[0964] Furthermore, the minimum mask line width at which the cured resist line was normally formed was examined and evaluated based on the following criteria.

[0965] Resolution "0" (good): when the minimum line width is less than 25 μm

[0966] Resolution "△" (OK): When the minimum line width is 25μm or more and less than 30μm

[0967] Resolution "×" (poor): When the minimum line width is 30μm or more

[0968] (iv) Fit test

[0969] After lamination was performed using the photosensitive elements obtained in each example and comparative example according to the above method, 15 minutes later, the samples thus obtained were subjected to direct drawing exposure according to the above method, and then developed according to the above method.

[0970] Furthermore, when line / space=X / 200, the minimum mask line width that can be normally formed is examined as X, and evaluation is performed based on the following criteria.

[0971] Adhesion "○" (good): When the minimum line width is less than 25 μm

[0972] Adhesion "△" (acceptable): When the minimum line width is 25 μm or more and less than 30 μm

[0973] Adhesion "×" (poor): When the minimum line width is 30μm or more

[0974] Examples 1 to 6 and Comparative Examples 1 to 5

[0975] The compositions of the photosensitive resin compositions used in Examples and Comparative Examples are shown in Table 3, and the details of the component names in Table 3 are shown in Table 4. The amounts of the components in Table 4 are all parts by mass in terms of solid content.

[0976] Table 4 also shows the evaluation results using each composition.

[0977]

[0978] Table 4. Details of ingredients

[0979]

[0980] <Examples and Comparative Examples According to the Third Embodiment>

[0981] Hereinafter, the photosensitive resin composition according to the third embodiment will be specifically described using examples.

[0982] The measurement of the physical property values ​​of polymers and monomers and the method for preparing evaluation samples of Examples and Comparative Examples are described. Next, the evaluation method for the obtained samples and the evaluation results are shown.

[0983] (1) Determination or calculation of physical property values

[0984] <Measurement of Weight Average Molecular Weight or Number Average Molecular Weight of Polymers>

[0985] The weight-average molecular weight or number-average molecular weight of the polymer was determined as a polystyrene-equivalent value using a gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 model, columns: four Shodex (registered trademark) (KF-807, KF-806M, KF-806M, KF-802.5) manufactured by Showa Denko K.K. connected in series, mobile phase solvent: tetrahydrofuran, using a calibration curve obtained from a polystyrene standard sample (Shodex STANDARD SM-105 manufactured by Showa Denko K.K.).

[0986] Furthermore, the polymer dispersion degree was calculated as the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight).

[0987] <Acid equivalent>

[0988] In this specification, acid equivalent refers to the mass (g) of a polymer having one equivalent of carboxyl groups in its molecule. Acid equivalent was measured by potentiometric titration using a Hiranuma automatic titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd. using a 0.1 mol / L sodium hydroxide aqueous solution.

[0989] (2) Method for preparing evaluation samples

[0990] Evaluation samples of Examples 1 to 12 and Comparative Examples 1 to 5 were prepared as follows.

[0991] <Production of Photosensitive Resin Laminate>

[0992] The components shown in Table 5 or 6 below (where the number for each component represents the amount (parts by mass) of the solid component) and a solvent were thoroughly stirred and mixed to obtain a photosensitive resin composition liquid. The names of the components represented by abbreviations in Tables 5 and 6 are shown in Table 7 below. A 16 μm thick polyethylene terephthalate film (R310-16B manufactured by Mitsubishi Plastics Co., Ltd.) was used as a support film. The prepared liquid was evenly applied to the surface using a bar coater and dried in a dryer at 95°C for 3 minutes to form a photosensitive resin composition layer. The dried thickness of the photosensitive resin composition layer was 30 μm.

[0993] Next, a 19 μm thick polyethylene film (GF-818 manufactured by Tamapoly Co., Ltd.) was attached as a protective layer to the surface of the photosensitive resin composition layer on which the polyethylene terephthalate film was not laminated, thereby obtaining a photosensitive resin laminate.

[0994] <Substrate surface finishing>

[0995] A 0.4 mm thick copper-clad laminate laminated with a 35 μm rolled copper foil was jet-grinded at a spray pressure of 0.2 MPa using an abrasive (Sakuram R (registered trademark #220, manufactured by Japan Carlit Co., Ltd.) to prepare an evaluation substrate.

[0996] <Lamination>

[0997] While peeling the polyethylene film from the photosensitive resin laminate, the photosensitive resin laminate was laminated onto a copper-clad laminate that had been surface-conditioned and preheated to 60°C using a hot roll laminator (AL-700, manufactured by Asahi Kasei Corporation) at a roll temperature of 105°C to produce a test piece. The air pressure was 0.35 MPa, and the lamination speed was 1.5 m / min.

[0998] <Exposure>

[0999] A direct writing exposure apparatus (manufactured by Via Mechanics Co., Ltd., DE-1DH, main wavelength 405 nm) was used at 15 mJ / cm 2 Exposure is performed with the exposure amount set.

[1000] <Development>

[1001] After peeling the polyethylene terephthalate film from the photosensitive resin laminate, a 1% by mass aqueous solution of NaCO at 30°C was sprayed for a predetermined time using a full-cone nozzle at a development spray pressure of 0.15 MPa using a development apparatus manufactured by Fuji Kikou Co., Ltd. to dissolve and remove the unexposed portions of the photosensitive resin layer. The minimum development time was determined as the minimum time required for complete dissolution of the unexposed portions of the photosensitive resin layer. Development was then continued for twice the minimum development time to produce a resist pattern. A water rinse step was performed using a flat nozzle at a water rinse spray pressure of 0.15 MPa for the same time as the development step.

[1002] (3) Sample evaluation method

[1003] <Pore-covering properties>

[1004] A 0.6mm thick, double-sided copper-clad laminate with through-holes measuring 2.0mm wide by 15mm long was surface treated using a jet scrubbing grinder. Both sides were laminated using the method described in "Lamination" above, and the entire surface of both sides was exposed using a direct-drawing exposure device (DE-1DH, manufactured by Via Mechanics Co., Ltd., with a dominant wavelength of 405nm). During development using the method described in "Development" above, the number of cracked cover holes was measured, and the crack rate relative to all cover holes was calculated. The cracks were then graded according to the following criteria.

[1005] ◎◎ (Best): The film breakage rate after development is 2% or less.

[1006] ⊚ (very good): The film breakage rate after development exceeds 2% and is 4% or less.

[1007] ○ (good): The film breakage rate after development exceeds 4% and is 10% or less.

[1008] × (poor): The film breakage rate after development exceeded 10%.

[1009] Contact Angle (Water Residual Short-Circuit Failure Suppression)

[1010] In the evaluation of the contact angle (short-circuit failure suppression due to residual water), lamination was performed by the method described in the above <Lamination>, followed by full-surface development by the method described in the above <Exposure>, and then development by the method described in the above <Development>.

[1011] After development, the sample was subjected to contact angle measurement within 30 minutes.

[1012] Contact angles were measured according to the sessile drop method of JIS R3257 using a Nic Corporation optical microscope contact angle meter "LSE-B100." After adding 0.5 μL of pure water to the cured film at 23°C and 50% humidity, contact angle measurement was initiated. The value after 120 seconds was used and graded according to the following criteria. A higher contact angle indicates high hydrophobicity of the cured resist, which can suppress short-circuiting failures caused by residual water.

[1013] ◎ (very good): The contact angle is 35° or more.

[1014] ○ (good): The contact angle is 30° or more and less than 35°.

[1015] Δ (permissible): The contact angle is 25° or more and less than 30°.

[1016] × (poor): The contact angle is less than 25°.

[1017] (4) Evaluation results

[1018] The evaluation results of Examples 1 to 12 are shown in Table 5 below, and the evaluation results of Comparative Examples 1 to 5 are shown in Table 6 below.

[1019]

[1020]

[1021] Table 7

[1022]

[1023] <Examples and Comparative Examples According to the Fourth Embodiment>

[1024] Hereinafter, the photosensitive resin composition according to the fourth embodiment will be specifically described using examples.

[1025] (1) Determination of physical properties of raw materials

[1026] <Measurement of weight average molecular weight>

[1027] The weight-average molecular weight of the polymer was determined as a polystyrene-equivalent value using a gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 model, columns: four Shodex (registered trademark) (KF-807, KF-806M, KF-806M, KF-802.5) manufactured by Showa Denko K.K. connected in series, mobile phase solvent: tetrahydrofuran, using a calibration curve obtained from a polystyrene standard sample (Shodex STANDARD SM-105 manufactured by Showa Denko K.K.).

[1028] <Acid equivalent>

[1029] In this specification, acid equivalent refers to the mass (g) of a polymer having one equivalent of carboxyl groups in the molecule. Acid equivalent was measured by potentiometric titration using a 0.1 mol / L sodium hydroxide aqueous solution using a Hiranuma automatic titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.

[1030] (2) Preparation and analysis of evaluation samples

[1031] <Production of Photosensitive Elements>

[1032] The components shown in Table 8 were mixed, and methyl ethyl ketone (MEK) was added to prepare a photosensitive resin composition having a solid content concentration of 56% by mass. The numbers in the component columns in Table 8 are the amounts (parts by mass) of the components used in the composition preparation.

[1033] The obtained photosensitive resin composition was uniformly coated on a 16 μm thick polyethylene terephthalate film (GR-16 manufactured by Teijin DuPont Films, haze value 2.7%) as a support using a bar coater, and then heated and dried in a dryer adjusted to 95°C for 3 minutes and 20 seconds to form a 33 μm thick photosensitive resin layer on the support.

[1034] Next, a polyethylene film (GF-18 manufactured by Tamapoly Co., Ltd.) having a thickness of 19 μm was attached as a protective layer to the surface of the photosensitive resin layer opposite to the support, thereby obtaining a photosensitive element.

[1035] <Substrates used in evaluation>

[1036] As an evaluation substrate, a 1.6 mm thick copper-clad laminate laminated with a 35 μm rolled copper foil was used, the surface of which was polished and conditioned by wet polishing roll grinding. Polishing was performed twice using Scotch (registered trademark) HD#600 manufactured by 3M.

[1037] <Lamination>

[1038] On the surface-conditioned substrate, while peeling off the polyethylene film of the photosensitive element obtained in each Example or Comparative Example, lamination was carried out using a hot roll laminator (AL-70, manufactured by Asahi Kasei Corporation) under the conditions of a roll temperature of 105°C, an air pressure of 0.35 MPa, and a lamination speed of 1.5 m / min.

[1039] <Exposure>

[1040] A direct writing exposure machine (DE-1AH manufactured by Hitachi Via Mechanics Co., Ltd., light source: GaN blue-violet diode, main wavelength 405±5 nm) was used, using a prescribed DI exposure mask pattern, at an illumination of 15 mW / cm 2 Exposure under conditions.

[1041] The exposure pattern and exposure amount will be described later in the section of each evaluation item.

[1042] <Development>

[1043] After peeling the support from the exposed photosensitive resin layer, an alkali developer (manufactured by Fuji Kikou Co., Ltd., dry film developer) was then sprayed with a 0.8% by mass NaCO aqueous solution at 29°C for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin layer. After development, the substrate was rinsed with pure water for the same time as the development time. After rinsing, the substrate was naturally dried without hot air drying, yielding a substrate having a cured film for evaluation.

[1044] The minimum development time is the minimum time required to completely dissolve and remove the unexposed portion of the photosensitive resin layer, and varies depending on the concentration and temperature of the developer, the direction and amount of spraying, the pressure, the frequency of vibration, and the like.

[1045] Here, the minimum development time is graded as follows:

[1046] ○: The minimum development time exceeds 30 seconds.

[1047] ×: The minimum development time is 30 seconds or less.

[1048] <Evaluation of sensitivity>

[1049] For the evaluation of sensitivity, a laminated substrate was used after 15 minutes had passed from the above-mentioned <Lamination>.

[1050] This laminated substrate was exposed to direct drawing using a mask pattern of 10 lines with a line / space ratio of 40 μm / 40 μm, followed by development using the method described in the above section "Development". The resulting resist pattern was measured for its top width using an optical microscope, and the exposure dose at which the top width reached 39 μm was used as the sensitivity evaluation.

[1051] Here, the resist line measurement position was set at the fifth line from the end of the 10 lines, approximately 5 mm from the end in the longitudinal direction, and the average value of three measurements was used as the measurement value. Because the line width differs between the edge and center of the pattern due to the influence of the diffusion of the developer and rinse water, the resist line tends to become thinner at the edge, so it is important to define the measurement position.

[1052] The exposure in the following evaluation items is the exposure that makes the resist top width reach 39 μm for a mask pattern of line / space = 40 μm / 40 μm, as described in the above <Evaluation of Sensitivity>. Here, the sensitivity is graded according to the exposure as follows:

[1053] ○: Exposure dose to achieve 39μm line width is 28mJ / cm 2 the following.

[1054] ×: Exposure dose exceeding 28 mJ / cm2 for a line width of 39 μm 2 .

[1055] <Resolution Evaluation>

[1056] The evaluation of resolution was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[1057] This laminated substrate was exposed to direct drawing in a line / space = 1 / 1 pattern of various sizes, and then developed by the method described in the above <Development>.

[1058] The obtained pattern was observed with an optical microscope to determine the minimum pattern width formed, and the resolution was evaluated based on the following criteria.

[1059] ◯: The minimum pattern width formed was 28 μm or less.

[1060] ×: The minimum pattern width formed exceeded 28 μm.

[1061] <Evaluation of Adhesion>

[1062] Evaluation of adhesion was performed using a laminated substrate 15 minutes after the above-mentioned <Lamination>.

[1063] This laminated substrate was exposed to direct drawing with patterns of independent lines of various sizes, and then developed by the method described in the above <Development>.

[1064] The obtained pattern was observed with an optical microscope, and the adhesiveness was evaluated according to the following criteria.

[1065] Here, the case where the line pattern is not formed normally refers to a case where the line pattern collapses, a case where the line pattern meanders, or a case where the line pattern does not exist on the substrate.

[1066] ◯: The minimum pattern width formed was 28 μm or less.

[1067] ×: The minimum pattern width formed exceeded 28 μm.

[1068] <Evaluation of Aggregation>

[1069] The thickness of the photopolymerizable resin laminate is 50 μm and the area is 0.6 m 2 The photosensitive layer (resist layer) is dissolved in 200 ml of a 1% by mass Na2CO3 aqueous solution and sprayed for 3 hours using a circulating spray device at a spray pressure of 0.1 MPa. Then, the developer is left to stand for 1 day and the generation of aggregates is observed. When a large amount of aggregates are generated, powdery or oily substances are observed at the bottom and sides of the spray device. In the composition with good developer aggregation, the above-mentioned aggregates are not generated at all. Based on the generation state of aggregates, the aggregation is classified as follows:

[1070] ○: Aggregates are not generated at all.

[1071] Δ: Aggregates were observed at the bottom or part of the side of the spray device.

[1072] ×: Aggregates were observed throughout the entire spray device.

[1073] <Evaluation of peeling properties>

[1074] Using the substrate treated 15 minutes after the treatment described in the above <Lamination>, a 4 cm×6 cm rectangular pattern was directly drawn and exposed on the laminated substrate, followed by development by the method described in the above <Development>.

[1075] The cured resist on the obtained substrate was immersed in 3% by mass NaOH at 50° C., and the time until the resist was completely peeled off from the substrate was measured as the peeling time.

[1076] Here, the peelability is graded as follows:

[1077] ○: The time until complete peeling was 40 seconds or less.

[1078] ×: The time until complete peeling exceeded 40 seconds.

[1079] Examples 1 to 7 and Comparative Examples 1 to 4

[1080] The compositions of the photosensitive resin compositions used in Examples and Comparative Examples are shown in Table 8, and the details of the component names in Table 8 are shown in Table 9. The amounts of the components in Table 8 are all parts by mass in terms of solid content.

[1081] Table 8 also shows the evaluation results using each composition.

[1082]

[1083] Table 9

[1084]

Claims

1. A photosensitive resin composition comprising: (A) Alkali-soluble polymer; (B) an ethylenically unsaturated bond-containing compound; and (C) a photopolymerization initiator; The alkali-soluble polymer (A) comprises a first copolymer containing 10% by mass or more and less than 25% by mass of acid monomer units and 30% by mass to 60% by mass of aromatic monomer units. The (A) alkali-soluble polymer comprises a second copolymer containing 45% to 90% by mass of aromatic monomer units, and The weight average molecular weight of the compound (B) containing an ethylenically unsaturated bond is 50 to 900, The (C) photopolymerization initiator comprises an acridine compound, The (C) photopolymerization initiator further comprises an N-aryl amino acid, A content of the acridine compound in the photosensitive resin composition is 0.1% by mass or more and 2.0% by mass or less.

2. The photosensitive resin composition according to claim 1, wherein The (B) ethylenically unsaturated bond-containing compound comprises a tri(meth)acrylate compound represented by the following general formula (III): In formula (III), R5, R6 and R7 independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 2 to 6 carbon atoms, m2, m3 and m4 independently represent integers of 0 to 40, m2+m3+m4 is 0 to 40, and when m2+m3+m4 is 2 or more, multiple Xs may be the same or different from each other.

3. The photosensitive resin composition according to claim 1 or 2, wherein The (B) ethylenically unsaturated bond-containing compound comprises an alkylene oxide-modified bisphenol A type di(meth)acrylate compound represented by the following general formula (II): In formula (II), R3 and R4 independently represent a hydrogen atom or a methyl group, A is C2H4, B is C3H6, n1, n2, n3 and n4 are integers satisfying the relationship n1+n2+n3+n4=2 to 50, and the arrangement of the repeating units of -(AO)- and -(BO)- can be random or block. In the case of block, any one of -(AO)- and -(BO)- can be on the biphenyl side.

4. The photosensitive resin composition according to any one of claims 1 to 3, wherein Hindered phenols also include compounds represented by the following general formula (V): In formula (V), R 51 represents an optionally substituted straight-chain alkyl group, a branched-chain alkyl group, an aryl group, a cyclohexyl group, a straight-chain alkyl group sandwiched by a divalent linking group, a branched-chain alkyl group sandwiched by a divalent linking group, a cyclohexyl group sandwiched by a divalent linking group, or an aryl group sandwiched by a divalent linking group, and R 52 、R 53 and R 54 Each independently represents hydrogen, or optionally substituted, straight-chain alkyl group, branched-chain alkyl group, aryl group, cyclohexyl group, straight-chain alkyl group sandwiched by a divalent linking group, branched-chain alkyl group sandwiched by a divalent linking group, cyclohexyl group sandwiched by a divalent linking group, or aryl group sandwiched by a divalent linking group. 5 . The photosensitive resin composition according to claim 1 , which is used for direct imagewise exposure. 6 . A photosensitive element comprising a photosensitive resin layer formed from the photosensitive resin composition according to claim 1 and laminated on a support.

7. A method for forming a resist pattern, comprising: a lamination step of laminating the photosensitive resin layer of the photosensitive element according to claim 6 on a conductive substrate; an exposing step of exposing the stacked photosensitive resin layer to light; and A developing step of developing the exposed photosensitive resin layer.

8. A method for manufacturing a circuit board, comprising: a lamination step of laminating the photosensitive resin layer of the photosensitive element according to claim 6 on a conductive substrate; an exposure step of exposing the stacked photosensitive resin layer to light; a developing step of developing the exposed photosensitive resin layer to form a resist pattern on the conductive substrate; a conductor pattern forming step of etching or plating the conductor substrate on which the resist pattern is formed; and A peeling step of peeling off the resist pattern.

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