Photosensitive resin composition, photosensitive element, method for producing wiring substrate, and photosensitive element roll

Abstract

This photosensitive resin composition contains a binder polymer having a constituent unit derived from benzyl (meth) acrylate, a photopolymerizable compound, a photopolymerization initiator, and a coumarin-based sensitizer.

Description

[0001] This application is a divisional application of the invention patent with an application date of November 12, 2020, application number 202080018491.6, and invention name "Photosensitive resin composition, photosensitive element, wiring substrate manufacturing method and photosensitive element roll" (International application No. PCT / JP2020 / 042340 entered the Chinese national stage). Technical Field

[0002] The present invention relates to a photosensitive resin composition, a photosensitive element, a method for producing a wiring substrate, and a photosensitive element roll. Background Art

[0003] In the manufacture of wiring boards, a resist pattern is formed to obtain the desired wiring. Photosensitive resin compositions are widely used in the formation of resist patterns. In recent years, MSAP (Modified SemiAdditive Process) has attracted attention as a method for forming fine wiring. In this method, in order to form fine wiring, it is necessary to form a resist pattern with higher precision than before.

[0004] In order to form a resist pattern with high precision, a photosensitizer is generally added to a photosensitive resin composition. As the photosensitizer, for example, anthracene derivatives such as 9,10-dibutoxyanthracene (DBA) are known (for example, refer to Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2007 / 004619 Summary of the invention

[0008] Technical issues to be solved by the invention

[0009] However, in order to obtain a more precise resist pattern, there is still room for improvement in the photosensitive resin composition containing DBA. In addition, the photosensitive resin composition is usually used in the form of a photosensitive element sandwiched between polymer films such as polyethylene. However, according to the research of the present inventors, when the photosensitive resin composition contains DBA, DBA permeates the polymer film, which may cause the problem that the desired pattern shape cannot be formed when the resist pattern is formed. This problem occurs particularly significantly when the polymer film is a polyethylene film.

[0010] Furthermore, the photosensitive resin composition containing DBA still has room for improvement in forming a resist pattern having excellent adhesion to a substrate.

[0011] Therefore, an object of the present invention is to provide a photosensitive resin composition and a photosensitive element capable of forming a resist pattern having excellent adhesion to a substrate and a good pattern shape, and a method for producing a wiring board and a photosensitive element roll using the same.

[0012] Means for solving technical problems

[0013] To achieve the above object, the present invention provides a photosensitive resin composition comprising a binder polymer having a structural unit based on benzyl (meth)acrylate, a photopolymerizable compound, a photopolymerization initiator, and a coumarin-based sensitizer.

[0014] According to the above-mentioned photosensitive resin composition, by using in combination a binder polymer and a coumarin-based sensitizer with a structural unit based on benzyl (meth) acrylate, it is possible to form a resist pattern having excellent adhesion to a substrate and having a good pattern shape. It can be considered that this is because coumarin-based sensitizers are more difficult to penetrate polymer films than DBA and can obtain higher sensitivity with less addition, so the pattern shape of the resist pattern can be made good, and by using this coumarin-based sensitizer and a binder polymer with a structural unit based on benzyl (meth) acrylate, it is possible to significantly improve the adhesion of the resist pattern to the substrate. And, since the coumarin-based sensitizer can reduce the addition, it is also possible to reduce the amount of solvent for dissolving the sensitizer. And then, since the absorbance of the coumarin-based sensitizer is lower than DBA, therefore when forming a resist pattern, the light exposed easily reaches the deep part of the photosensitive resin layer, and the photocurability at the bottom of the photosensitive resin layer can be improved. Therefore, it is possible to further improve adhesion, resolution and pattern shape.

[0015] In the photosensitive resin composition, the content of the coumarin sensitizer may be 0.01 to 0.5 parts by mass relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. Since the content of the coumarin sensitizer is within the above range, the excellent adhesion of the resist pattern and the good pattern shape can be achieved at a higher level.

[0016] In the photosensitive resin composition, the content ratio of the structural unit based on benzyl (meth)acrylate in the binder polymer may be 10 to 60% by mass based on the total amount of monomers constituting the binder polymer.

[0017] In the photosensitive resin composition, the binder polymer may have a styrene-based structural unit. Since the binder polymer includes a styrene-based structural unit, it is possible to simultaneously achieve excellent adhesion and good pattern shape of the resist pattern at a higher level. In addition, in the binder polymer, the content ratio of the styrene-based structural unit can be 10 to 50% by mass based on the total amount of monomers constituting the binder polymer.

[0018] In the photosensitive resin composition, the binder polymer may have a structural unit based on alkyl (meth)acrylate, and the content of the structural unit based on alkyl (meth)acrylate may be 5 to 40% by mass based on the total amount of monomers constituting the binder polymer.

[0019] In the photosensitive resin composition, the binder polymer may have a structural unit based on (meth)acrylic acid, and the content of the structural unit based on (meth)acrylic acid may be 10 to 40% by mass based on the total amount of monomers constituting the binder polymer.

[0020] The photosensitive resin composition may contain a polymerization inhibitor. Furthermore, the content of the polymerization inhibitor in the photosensitive resin composition may be 0.003 parts by mass or less relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. Since the content of the polymerization inhibitor is within the above range, the pattern shape of the resist pattern can be made better.

[0021] Furthermore, the content of the polymerization inhibitor in the photosensitive resin composition may be 0.001 parts by mass or more relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. Since the content of the polymerization inhibitor is within the above range, the excellent adhesion and good pattern shape of the resist pattern can be achieved at a higher level, and the thickening of the lines of the resist pattern can be suppressed.

[0022] Furthermore, the polymerization inhibitor may contain tert-butylcatechol. Since the polymerization inhibitor contains tert-butylcatechol, it is possible to achieve both excellent adhesion and good pattern shape of the resist pattern at a higher level, and it is possible to suppress the occurrence of thickening of lines in the resist pattern.

[0023] The photosensitive resin composition may contain 2,6-di-tert-butyl-p-cresol as an antioxidant. Furthermore, the content of the 2,6-di-tert-butyl-p-cresol in the photosensitive resin composition may exceed 0.002 parts by mass relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. Since the content of 2,6-di-tert-butyl-p-cresol is within the above range, the adhesion of the resist pattern can be further improved, and the thickening of the lines of the resist pattern can be suppressed.

[0024] In the photosensitive resin composition, the photopolymerization initiator may contain a 2,4,5-triarylimidazole dimer.

[0025] In the photosensitive resin composition, the photopolymerizable compound may include a bisphenol A di(meth)acrylate compound. Furthermore, the bisphenol A di(meth)acrylate compound may include 2,2-bis(4-((meth)acryloyloxypentaethoxy)phenyl)propane and / or 2,2-bis(4-((meth)acryloyloxydiethoxy)phenyl)propane.

[0026] The photosensitive resin composition may contain colorless crystal violet.

[0027] The present invention also provides a photosensitive element comprising: a support; and a photosensitive resin layer formed on the support using the photosensitive resin composition of the present invention.

[0028] The present invention also provides a method for manufacturing a wiring substrate, which comprises: a process of providing a photosensitive resin layer on a substrate using the above-mentioned photosensitive resin composition of the present invention or the above-mentioned photosensitive element of the present invention; a process of photocuring a portion of the above-mentioned photosensitive resin layer; a process of removing the uncured portion of the above-mentioned photosensitive resin layer to form a resist pattern; and a process of forming a wiring layer on the portion of the above-mentioned substrate where the above-mentioned resist pattern is not formed.

[0029] The present invention also provides a photosensitive element roll including a winding core and the photosensitive element of the present invention wound around the winding core.

[0030] Effects of the Invention

[0031] According to the present invention, there can be provided a photosensitive resin composition and a photosensitive element capable of forming a resist pattern having excellent adhesion to a substrate and a good pattern shape, and a method for producing a wiring board and a photosensitive element roll using the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic cross-sectional view showing a photosensitive element according to one embodiment.

[0033] Figure 2 It is a schematic diagram showing a method for manufacturing a wiring board according to one embodiment. DETAILED DESCRIPTION

[0034] Hereinafter, embodiments of the present invention will be described in detail.

[0035] In this specification, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved. The numerical range represented by "to" means a range that includes the numerical values ​​recorded before and after "to" as the minimum and maximum values, respectively. "(Meth)acrylic acid" refers to at least one of "acrylic acid" and its corresponding "methacrylic acid". The same applies to other similar expressions such as (meth)acrylates. In this specification, "EO modified" refers to a compound having (poly)ethylene oxide.

[0036] In this specification, when there are multiple substances corresponding to each component in the composition, the amount of each component in the composition refers to the total amount of the multiple substances in the composition unless otherwise specified. In this specification, "solid content" refers to non-volatile components other than volatile substances (water, solvent, etc.) in the photosensitive resin composition. That is, "solid content" refers to components other than the solvent that does not volatilize and remains during the drying of the photosensitive resin composition described later, and also includes components that are liquid, maltose-like or waxy at room temperature (25°C).

[0037] <Photosensitive resin composition>

[0038] The photosensitive resin composition of the present embodiment contains (A) component: binder polymer, (B) component: photopolymerizable compound, (C) component: photopolymerization initiator and (D) component: coumarin-based sensitizer. Here, (A) component has a structural unit based on benzyl (meth)acrylate. In addition, the photosensitive resin composition of the present embodiment may also contain (E) component: polymerization inhibitor. The following describes each component.

[0039] (A) Component: Binder polymer

[0040] The photosensitive resin composition comprises one or more components (A). As the component (A), a binder polymer having a structural unit based on benzyl (meth)acrylate is contained. In addition, the aromatic ring of the benzyl (meth)acrylate may have a substituent.

[0041] In the binder polymer as component (A), the content ratio of the structural unit based on benzyl (meth)acrylate is preferably 10 to 60% by mass based on the total amount of the monomers constituting component (A), more preferably 15 to 55% by mass, further preferably 15 to 35% by mass, particularly preferably 20 to 30% by mass, and extremely preferably 20 to 23% by mass. Thus, the photosensitive resin composition layer containing the photosensitive resin composition can have good adhesion and resist stripping properties to the circuit forming substrate. In addition, the content ratio of the structural unit based on the above-mentioned benzyl (meth)acrylate can be less than 23% by mass based on the total amount of the monomers constituting component (A), or can be less than 22% by mass.

[0042] From the viewpoint of further improving resolution and adhesion, the binder polymer may have a structural unit based on styrene. Styrene may have a substituent such as vinyltoluene or α-methylstyrene.

[0043] The content ratio of the styrene-based structural units is based on the total amount of monomers constituting the (A) component. From the viewpoint of further improving the resolution, it can be 10% by mass or more, 20% by mass or more, or 30% by mass or more. From the viewpoint of excellent peeling properties, it can be 50% by mass or less, 45% by mass or less, or 40% by mass or less.

[0044] The binder polymer may have a structural unit based on an alkyl (meth)acrylate from the viewpoint of improving alkali developability and peeling properties. The alkyl (meth)acrylate may have a structural unit based on methyl (meth)acrylate.

[0045] The content ratio of the structural unit based on the (meth)acrylate ester is based on the total amount of the monomers constituting the (A) component, and from the viewpoint of excellent release properties, it can be 5% by mass or more, 10% by mass or more, or 14% by mass or more, and from the viewpoint of further improving the resolution and adhesion, it can be 40% by mass or less, 30% by mass or less, or 20% by mass or less.

[0046] The binder polymer may have a structural unit based on (meth) acrylic acid. The content of the structural unit based on (meth) acrylic acid may be 10 to 40% by mass, 15 to 30 parts by mass, 20 to 30 parts by mass, or 20 to 25 parts by mass based on the total amount of the monomers constituting the component (A). Thus, the resist stripping properties and developability can be improved.

[0047] The acid value of component (A) may be 60 mgKOH / g or more, 65 mgKOH / g or more, 70 mgKOH / g or more, or 75 mgKOH / g or more from the viewpoint of enabling appropriate development, and may be 250 mgKOH / g or less, 240 mgKOH / g or less, or 230 mgKOH / g or less from the viewpoint of improving the adhesion (developer resistance) of the cured product of the photosensitive resin composition. The acid value of component (A) may be adjusted by the content of the structural unit constituting component (e.g., the structural unit derived from (meth)acrylic acid).

[0048] The weight average molecular weight (Mw) of the component (A) may be 10,000 or more, 20,000 or more, or 25,000 or more from the viewpoint of excellent adhesion (developer resistance) of the cured product of the photosensitive resin composition, and may be 80,000 or less, 50,000 or less, or 40,000 or less from the viewpoint of enabling appropriate development. The degree of dispersion (Mw / Mn) of the component (A) may be, for example, 1.5 or more or 2.0 or more, and may be 3.5 or less or 3.3 or less from the viewpoint of further improving adhesion and resolution.

[0049] Weight average molecular weight and dispersity can be measured by gel permeation chromatography (GPC) and using the calibration curve of standard polystyrene, for example. More specifically, it is possible to measure under the conditions described in the embodiments. In addition, for compounds with low molecular weight, when it is difficult to measure by the measuring method of the above-mentioned weight average molecular weight, it is also possible to measure the molecular weight by other methods, and calculate its average value.

[0050] The content of component (A) may be 20% by mass or more, 30% by mass or more, or 40% by mass or more, based on the total solid content of the photosensitive resin composition, from the viewpoint of excellent film formability, and may be 90% by mass or less, 80% by mass or less, or 65% by mass or less, from the viewpoint of better sensitivity and resolution.

[0051] The content of component (A) relative to 100 parts by mass of the total amount of component (A) and component (B) may be 30 parts by mass or more, 35 parts by mass or more, or 40 parts by mass or more from the viewpoint of excellent film formability, and may be 70 parts by mass or less, 65 parts by mass or less, or 60 parts by mass or less from the viewpoint of further improving sensitivity and resolution.

[0052] The photosensitive resin composition may or may not contain a binder polymer other than the component (A) (ie, a binder polymer not having a structural unit based on benzyl (meth)acrylate).

[0053] (B) Component: Photopolymerizable compound

[0054] The photosensitive resin composition contains one or more components (B). The component (B) may be a compound polymerized by light, for example, a compound having an ethylenically unsaturated bond.

[0055] From the viewpoint of further improving alkali developability, resolution, and release characteristics after curing, the component (B) may contain a bisphenol A-type di(meth)acrylate compound.

[0056] Examples of the bisphenol A type di(meth)acrylate compound include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane (2,2-bis(4-((meth)acryloxypentaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane.

[0057] From the viewpoint of further improving the resolution and the peeling characteristics, the component (B) may contain 2,2-bis(4-((meth)acryloxypentaethoxy)phenyl)propane or 2,2-bis(4-((meth)acryloxydiethoxy)phenyl)propane, or 2,2-bis(4-(meth)acryloxypentaethoxy)phenyl)propane and 2,2-bis(4-((meth)acryloxydiethoxy)phenyl)propane may be used in combination.

[0058] From the viewpoint of further improving the resolution of the resist, the content of the bisphenol A di(meth)acrylate compound may be 60% by mass or more, or 70% by mass or more, or 99% by mass or less, 95% by mass or less, or 90% by mass or less, based on the total amount of the component (B).

[0059] From the viewpoint of further improving the peelability, adhesion and flexibility, the component (B) may contain trimethylolpropane tri(meth)acrylate or tetramethylolmethane tri(meth)acrylate. In addition, trimethylolpropane tri(meth)acrylate or tetramethylolmethane tri(meth)acrylate may be EO-modified, PO-modified or EO / PO-modified.

[0060] The content of trimethylolpropane tri(meth)acrylate or tetramethylolmethane tri(meth)acrylate may be 1% by mass or more or 10% by mass or more from the viewpoint of further improving developability, adhesion and pattern shape, and may be 30% by mass or less or 25% by mass or less from the viewpoint of further improving releasability, based on the total amount of component (B).

[0061] From the viewpoint of further improving the sensitivity and resolution, the content of component (B) can be 3% by mass or more, 10% by mass or more, or 25% by mass or more, based on the total solid content of the photosensitive resin composition. From the viewpoint of excellent film formability, the content can be 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0062] Component (C): Photopolymerization initiator

[0063] The photosensitive resin composition contains one or more components (C). Examples of the component (C) include 2,4,5-triarylimidazole dimers, aromatic ketone compounds, benzoin compounds, and phosphine oxide compounds.

[0064] From the viewpoint of further suppressing the permeation of the photosensitizer into the polyethylene film, the component (C) may contain a 2,4,5-triarylimidazole dimer. The hydrogen atom bonded to the phenyl group in the 2,4,5-triarylimidazole dimer may be substituted with a halogen atom (chlorine atom, etc.).

[0065] Examples of the 2,4,5-triaryl imidazole dimer include 2-(o-chlorophenyl)-4,5-diphenyl imidazole dimer, 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl) imidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenyl imidazole dimer. From the viewpoint of further suppressing the permeation of the photosensitizer into the polyethylene film, the 2,4,5-triaryl imidazole dimer may be 2-(o-chlorophenyl)-4,5-diphenyl imidazole dimer or 2,2-bis(o-chlorophenyl)-4,5,4',5'-tetraphenyl-1,2'biimidazole.

[0066] From the viewpoint of further suppressing the penetration of the photosensitizer into the polyethylene film, the content of the 2,4,5-triaryl imidazole dimer may be 90 mass % or more, 95 mass % or more, or 99 mass % or more based on the total amount of the component (C). The component (C) may consist only of the 2,4,5-triaryl imidazole dimer.

[0067] From the viewpoint of further improving sensitivity and adhesion, the content of the component (C) may be 1% by mass or more, 2% by mass or more, or 3% by mass or less, and may be 10% by mass or less, 8% by mass or less, or 6% by mass or less, based on the total solid content of the photosensitive resin composition.

[0068] (D) Ingredient: Coumarin-based sensitizer

[0069] The photosensitive resin composition contains one or more components (D). The component (D) serves as a photosensitizer. Examples of the component (D) include compounds represented by the following general formula (1).

[0070]

[0071] In the formula, Z 1 and Z 2 Each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an amino group, an alkylamino group having 1 to 10 carbon atoms, a dialkylamino group having 2 to 20 carbon atoms, a mercapto group, an alkylmercapto group having 1 to 10 carbon atoms, an allyl 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, or a group containing a heterocyclic ring, and n represents an integer of 0 to 4, and m represents an integer of 0 to 2. In addition, n Z 1 and m Z 2 At least two of them may form a ring.

[0072] In the general formula (1), at least one Z 1 Preferably substituted at position 7, at least one Z 2 Preferably, the 4-position is substituted. Also, from the viewpoint of sensitivity, the 3-position is preferably unsubstituted.

[0073] Examples of the halogen atom in the general formula (1) include fluorine, chlorine, bromine, iodine, and astatine. Examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, and structural isomers thereof. Examples of the cycloalkyl group having 3 to 10 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of the aryl group having 6 to 14 carbon atoms include phenyl, tolyl, xylyl, biphenyl, naphthyl, anthracenyl, and phenanthryl. These may be substituted with a halogen atom, an amino group, a nitro group, a cyano group, a mercapto group, an allyl group, or an alkyl group having 1 to 20 carbon atoms. Examples of the alkylamino group having 1 to 10 carbon atoms include methylamino, ethylamino, propylamino, and isopropylamino. Examples of the dialkylamino group having 2 to 20 carbon atoms include dimethylamino, diethylamino, dipropylamino, and diisopropylamino. Examples of the alkylmercapto group having 1 to 10 carbon atoms include methylmercapto, ethylmercapto, and propylmercapto. Examples of the hydroxyalkyl group having 1 to 20 carbon atoms include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxyisopropyl, and hydroxybutyl. Examples of the carboxyalkyl group having 1 to 10 carbon atoms as the alkyl group include carboxymethyl, carboxyethyl, carboxypropyl, and carboxybutyl. In addition, examples of the acyl group having 1 to 10 carbon atoms in the alkyl group include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, etc., and examples of the alkoxy group having 1 to 20 carbon atoms include methoxy, ethoxy, propoxy, butoxy, etc. In addition, examples of the alkoxycarbonyl group having 1 to 20 carbon atoms include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, etc., and examples of the group containing a heterocyclic ring include furyl, thienyl, pyrrolyl, thiazolyl, indolyl, quinolyl, etc.

[0074] In the general formula (1), Z 1 and Z 2 Each of the Z groups independently is preferably an alkyl group having 1 to 20 carbon atoms, an amino group, an alkylamino group having 1 to 10 carbon atoms, or a dialkylamino group having 2 to 20 carbon atoms. 1 and m Z 2 At least two of them may form a ring.

[0075] From the viewpoint of resolution and photosensitivity, the coumarin compound represented by the general formula (1) is more preferably a compound represented by the following general formula (2). 1 , Z 2and m and the above Z 1 , Z 2 and m have the same meaning, Z 11 and Z 12 Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and r represents an integer of 0 to 3. 1 , m Z 2 , Z 11 and Z 12 At least two of them may form a ring. In the compound represented by the following general formula (2), Z 11 and Z 12 Each of them is independently preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. 1 and Z 2 Same as above.

[0076]

[0077] As a compound represented by the general formula (2) and m Z 2 , Z 11 and Z 12 In the embodiment where at least two of the compounds form a ring, there can be mentioned compounds represented by the following general formula (3) and compounds represented by the following general formula (4).

[0078]

[0079] In the formula, Z 1 , Z 11 , Z 12 and r and the above Z 1 , Z 11 , Z 12 and r have the same meaning, Z 21 Indicates that the above Z 1 The same atom or group. Also, s represents an integer of 0 to 8. In addition, Z is preferably 1 , Z 11 and Z 12 Same as above.

[0080]

[0081] In the formula, Z 1 , Z 2 and m and the above Z 1 , Z 2 and m have the same meaning, Z 31 and Z 32 Respectively independently represent the above Z 1The same atom or group. In addition, t represents an integer of 0 to 1, u represents an integer of 0 to 6, and v represents an integer of 0 to 6. In addition, Z is preferably 1 and Z 2 Same as above.

[0082] Examples of the compound represented by the general formula (2) (including compounds represented by the general formulae (3) and (4)) include 7-amino-4-methylcoumarin, 7-dimethylamino-4-methylcoumarin, 7-diethylamino-4-methylcoumarin (a compound represented by the following formula (5)), 7-methylamino-4-methylcoumarin, 7-ethylamino-4-methylcoumarin, 4,6-dimethyl-7-ethylaminocoumarin (a compound represented by the following formula (6)), 4,6-diethyl-7-ethylaminocoumarin, 4,6-dimethyl-7-diethylaminocoumarin, 4,6-dimethyl-7-dimethylaminocoumarin, 4,6-diethyl-7-ethylaminocoumarin, 4,6-dimethyl-7-dimethylaminocoumarin, 4,6-diethyl-7-ethylaminocoumarin, 4,6-diethyl-7-ethylaminocoumarin. -7-dimethylaminocoumarin, 4,6-dimethyl-7-ethylaminocoumarin, 7-dimethylaminocyclopentane[c]coumarin (a compound represented by the following formula (7)), 7-aminocyclopentane[c]coumarin, 7-diethylaminocyclopentane[c]coumarin, 2,3,6,7,10,11-hexahydrate-1H,5H-cyclopenta[3,4][1]benzopyrano[6,7,8-ij]quinolizin-12(9H)-one, 7-diethylamino-5',7'-dimethoxy-3,3'-carbonylbiscoumarin, 3,3'-carbonylbis[7-(diethylamino)coumarin], 7-(diethylamino)-3-(2-thienyl)coumarin, and a compound represented by the following formula (8).

[0083]

[0084] As the coumarin compound represented by the general formula (1), the compound represented by the general formula (4) is particularly preferred. By using the compound represented by the general formula (4) as the component (D) in combination with the binder polymer having a structural unit based on benzyl (meth)acrylate as the component (A), the sensitivity, adhesion and resolution can be greatly improved, and even if only a small amount of the component (D) is added, these effects can be fully obtained.

[0085] From the viewpoint of further improving sensitivity, adhesion and resolution, the content of component (D) is, for example, 0.01 part by mass or more, preferably 0.02 part by mass or more, more preferably 0.03 part by mass or more, and further preferably 0.04 part by mass or more, relative to 100 parts by mass of the total amount of component (A) and component (B). From the viewpoint of making the resist pattern shape better, the content is, for example, 0.5 part by mass or less, preferably 0.4 part by mass or less, more preferably 0.3 part by mass or less, further preferably 0.2 part by mass or less, particularly preferably 0.15 part by mass or less, and extremely preferably 0.1 part by mass or less.

[0086] The photosensitive resin composition may contain a known photosensitizer as another photosensitizer in addition to the component (D). The content of the other sensitizer may be, for example, 0.01 to 0.50 parts by mass or 0.05 to 0.20 parts by mass relative to 100 parts by mass of the total amount of the components (A) and (B).

[0087] (E) Component: Polymerization Inhibitor

[0088] From the viewpoint of suppressing polymerization in the unexposed portion during resist pattern formation and further improving resolution, the photosensitive resin composition may further contain component (E): a polymerization inhibitor. Examples of the polymerization inhibitor include tert-butylcatechol and 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-N-oxyl.

[0089] Examples of the polymerization inhibitor include catechol, resorcinol (resorcinol), 1,4-hydroquinone, 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, 3,5- Alkyl catechols such as di-tert-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol (orcinol), 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, 4-tert-butylresorcinol and other alkylresorcinols, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, alkylhydroquinones such as 2,5-di-tert-butylhydroquinone, pyrogallol, phloroglucinol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl, etc. These may be used alone or in combination of two or more.

[0090] Since the photosensitive resin composition contains component (D), even if it does not contain a polymerization inhibitor, it is possible to suppress polymerization in the unexposed portion during the formation of the resist pattern, and the resist pattern can be formed with higher precision, compared with the case of containing an existing photosensitizer (such as DBA). Thus, the content of component (E) relative to 100 parts by mass of the total amount of component (A) and component (B) can be 0.01 parts by mass or less, 0.005 parts by mass or less, 0.003 parts by mass or less, 0.0025 parts by mass or less, or 0.002 parts by mass or less, and the photosensitive resin composition may not contain component (E). On the other hand, since the photosensitive resin composition contains component (E), it is possible to further improve the adhesion and the shape of the resist pattern, and it is possible to suppress the thickening of the lines of the resist pattern. Therefore, the content of component (E) relative to 100 parts by mass of the total amount of component (A) and component (B) can be 0.001 parts by mass or more, 0.0015 parts by mass or more, or 0.002 parts by mass or more.

[0091] The photosensitive resin composition may also contain one or more other ingredients other than the above-mentioned ingredients. As other ingredients, hydrogen donors (bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, colorless crystal violet, N-phenylglycine, etc.), dyes (malachite green, etc.), tribromophenyl sulfone, photochromic agents, thermal color inhibitors, plasticizers (p-toluenesulfonamide, etc.), pigments, fillers, defoamers, flame retardants, stabilizers, adhesion imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. can be listed. The content of other ingredients can be 0.005 mass parts or more or 0.01 mass parts or less, or 20 mass parts or less relative to the total amount of 100 mass parts of (A) component and (B) component.

[0092] Examples of the antioxidant include alkylated phenols such as 2,6-di-tert-butyl-4-methylphenol, alkylated bisphenols such as 2,2-methylenebis(4-methyl-6-tert-butylphenol), 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2-4-hydroxy-3,5-di-tert-butylaniline-4,6-bis(n-octylthio)-1,3,5-triazine, dilaurylthiodipropionate benzotriazole, benzotriazole hydrochloride, benzotriazole organic acid salts, and aminobenzothiazole. Furthermore, as antioxidants, phenols such as 4,4'-butylene-bis(6-tert-butyl-m-cresol), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(6-tert-butyl-m-cresol), 2,6-di-tert-butyl-p-cresol, 2,5-di-tert-amylhydroquinone, 2,5-di-tert-butylhydroquinone, 2-methyl-4,6-bis[(octylthio)methyl]phenol, and 2,4-bis(dodecylthiomethyl)-6-methylphenol can be used. These can be used alone or in combination of two or more.

[0093] The antioxidant preferably includes 2,6-di-tert-butyl-p-cresol (also known as butylated hydroxytoluene, abbreviated as BHT). When the photosensitive resin composition includes BHT, the adhesion and resist pattern shape can be further improved, and thickening of the lines of the resist pattern can be suppressed.

[0094] The content of the antioxidant in the photosensitive resin composition can be 0.001 mass parts or more, 0.002 mass parts or more, more than 0.002 mass parts, 0.003 mass parts or more, or 0.005 mass parts or more, or 0.5 mass parts or less, 0.3 mass parts or less, or 0.1 mass parts or less relative to the total amount 100 mass parts of (A) component and (B) component. Since the content of the antioxidant is above the lower limit, the adhesion and the resist pattern shape can be further improved, and the thickening of the lines of the resist pattern can be suppressed. In addition, since the content of the antioxidant is below the upper limit, the sensitivity can be suppressed from being significantly reduced.

[0095] From the viewpoint of adjusting the viscosity, the photosensitive resin composition may also contain one or more organic solvents. As the organic solvent, for example, methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, etc. may be cited. The content of the organic solvent may be more than 40% by mass or less than 70% by mass based on the total amount of the photosensitive resin composition. As the organic solvent, for example, a mixed solvent of toluene and other solvents (methanol, ethanol, methyl cellosolve, ethyl cellosolve, etc.) may be used. In the case where the photosensitive resin composition includes a coumarin-based sensitizer, even if the proportion of toluene in the above-mentioned mixed solvent is reduced, good solubility is easily obtained, so the amount of toluene used can be reduced.

[0096] The photosensitive resin composition can be suitably used for formation of a resist pattern, and can be particularly suitably used for a method for producing a wiring board to be described later.

[0097] <Photosensitive element>

[0098] Figure 1 is a schematic cross-sectional view of a photosensitive element according to one embodiment. Figure 1 As shown, the photosensitive element 1 includes a support 2 , a photosensitive resin layer 3 provided on the support 2 , and a protective layer 4 provided on the side of the photosensitive resin layer 3 opposite to the support 2 .

[0099] The support 2 and the protective layer 4 may be polymer films having heat resistance and solvent resistance, for example, polyester films such as polyethylene terephthalate films, polyolefin films such as polyethylene films and polypropylene films, etc. The support 2 and the protective layer 4 may be films of hydrocarbon polymers other than polyolefins. The film of hydrocarbon polymers including polyolefins may be low-density, for example, it may have a density of 1.014 g / cm or less. The support 2 and the protective layer 4 may be stretched films formed by stretching the low-density hydrocarbon polymer film. The type of the polymer film constituting the protective layer 4 may be the same as or different from the type of the polymer film constituting the support 2.

[0100] These polymer films are commercially available as polyethylene terephthalate films such as PS series (e.g., PS-25) manufactured by Teijin Limited, polyethylene films such as NF-15 manufactured by TAMAPOLY CO., LTD., or polypropylene films such as OJI PAPER CO., LTD. (e.g., ALPHAN MA-410, E-200C) and SHIN-ETSU FILM CO., LTD.

[0101] From the viewpoint of suppressing damage to the support 2 when peeling the support 2 from the photosensitive resin layer 3, the thickness of the support 2 may be greater than 1 μm or greater than 5 μm, and from the viewpoint of enabling appropriate exposure when exposure is performed through the support 2, the thickness may be less than 100 μm, less than 50 μm, or less than 30 μm.

[0102] When the photosensitive resin layer 3 and the support body 2 are laminated on the substrate while peeling off the protective layer 4, the thickness of the protective layer 4 can be greater than 1 μm, greater than 5 μm or greater than 15 μm from the viewpoint of suppressing damage to the protective layer 4, and can be less than 100 μm, less than 50 μm or less than 30 μm from the viewpoint of improving productivity.

[0103] The photosensitive resin layer 3 is composed of the above-mentioned photosensitive resin composition. From the viewpoint of facilitating coating and improving productivity, the thickness of the photosensitive resin layer 3 after drying (after volatilizing the organic solvent when the photosensitive resin composition contains an organic solvent) can be 1 μm or more or 5 μm or more, and from the viewpoint of further improving adhesion and resolution, it can be 100 μm or less, 50 μm or less, or 40 μm or less.

[0104] The photosensitive element 1 can be obtained, for example, as follows. First, a photosensitive resin layer 3 is formed on a support 2. The photosensitive resin layer 3 can be formed, for example, by coating a photosensitive resin composition containing an organic solvent to form a coating layer and drying the coating layer. Next, a protective layer 4 is formed on the surface of the photosensitive resin layer 3 on the opposite side of the support 2.

[0105] The coating layer is formed by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, rod coating, etc. The coating layer is dried so that the amount of the organic solvent remaining in the photosensitive resin layer 3 is, for example, 2% by mass or less, specifically, for example, at 70 to 150° C. for about 5 to 30 minutes.

[0106] In another embodiment, the photosensitive element may not include the protective layer, and may include other layers such as a buffer layer, an adhesive layer, a light absorbing layer, and a gas barrier layer.

[0107] The photosensitive element 1 may be in the form of a sheet, or may be in the form of a photosensitive element roll wound on a core in a roll shape. In the photosensitive element roll, the photosensitive element 1 is preferably wound so that the support 2 is on the outside. The core is formed of, for example, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, etc. From the viewpoint of end face protection, an end face separator may be provided on the end face of the photosensitive element roll, and from the viewpoint of edge fusion resistance, a moisture-proof end face separator may be provided. The photosensitive element 1 may be packaged with, for example, a black sheet material with low moisture permeability.

[0108] The photosensitive element 1 can be applied to the formation of a resist pattern, and can be particularly applied to the method for manufacturing a wiring substrate described later. Compared with the conventional photosensitive element, the photosensitive element 1 can suppress the penetration of the photosensitizer into the polyethylene film, so at least one of the support 2 and the protective layer 4 can be a polyethylene film, or can be the above-mentioned low-density hydrocarbon polymer film or its stretched film.

[0109] <Method for manufacturing wiring board>

[0110] Figure 2 Schematic diagram showing a method for manufacturing a wiring substrate (also referred to as a printed wiring board) according to an embodiment of the present invention. In the manufacturing method, first, Figure 2 As shown in (a), a substrate (for example, a circuit forming substrate) is prepared which has an insulating layer 11 and a conductive layer 12 formed on the insulating layer 11. The conductive layer 12 may be, for example, a metal copper layer.

[0111] Then, if Figure 2 As shown in (b), a photosensitive resin layer 13 is provided on the substrate (conductive layer 12). In this process, the photosensitive resin composition or the photosensitive element 1 is used to form a photosensitive resin layer 13 composed of the photosensitive resin composition on the substrate (conductive layer 12). For example, the photosensitive resin layer 13 is formed by applying the photosensitive resin composition on the substrate and drying it. Alternatively, the photosensitive resin layer 13 is formed by removing the protective layer 4 from the photosensitive element 1 and then pressing the photosensitive resin layer 3 of the photosensitive element 1 onto the substrate while heating it. When pressing, at least one of the photosensitive resin layer 3 and the substrate can be heated at 70 to 130° C., for example. The pressure during pressing can be 0.1 to 1.0 MPa, for example.

[0112] Then, if Figure 2 As shown in (c), a mask 14 is arranged on the photosensitive resin layer 13, and an active light 15 is irradiated to expose the region other than the region where the mask 14 is arranged to photo-cure the photosensitive resin layer 13. The light source of the active light 15 can be, for example, an ultraviolet light source or a visible light source such as a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, a gas laser (argon laser, etc.), a solid-state laser (YAG laser, etc.), or a semiconductor laser.

[0113] In another embodiment, the active light 15 may be irradiated in a desired pattern by a direct writing exposure method such as an LDI exposure method or a DLP exposure method without using the mask 14 , thereby exposing a portion of the photosensitive resin layer 13 .

[0114] Then, if Figure 2As shown in (d), the region (uncured portion) other than the photocured portion formed by exposure is removed from the substrate by development, thereby forming a resist pattern 16 composed of the photocured portion (cured product of the photosensitive resin layer). The development method may be, for example, wet development or dry development, preferably wet development.

[0115] Wet development is performed using a developer corresponding to the photosensitive resin composition by methods such as dipping, paddle, spray, brushing, slapping, scraping, shaking and dipping. The developer is appropriately selected according to the structure of the photosensitive resin composition and may be an alkali developer or an organic solvent developer.

[0116] The alkaline developer can be an aqueous solution of an alkali such as a hydroxide of lithium, sodium or potassium; an alkali carbonate such as a carbonate or bicarbonate of lithium, sodium, potassium or ammonium; an alkali metal phosphate such as potassium phosphate and sodium phosphate; an alkali metal pyrophosphate such as sodium pyrophosphate and potassium pyrophosphate; borax; sodium metasilicate; tetramethylammonium hydroxide; ethanolamine; ethylenediamine; diethylenetriamine; 2-amino-2-hydroxymethyl-1,3-propanediol; 1,3-diamino-2-propanol; or morpholine.

[0117] The alkali developer may be, for example, a 0.1-5 mass % sodium carbonate aqueous solution, a 0.1-5 mass % potassium carbonate aqueous solution, a 0.1-5 mass % sodium hydroxide aqueous solution, a 0.1-5 mass % sodium tetraborate aqueous solution, etc. The pH of the alkali developer may be, for example, 9-11.

[0118] The alkaline developer may further contain a surfactant, a defoamer, an organic solvent, etc. Examples of the organic solvent include acetone, ethyl acetate, an alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethanol, isopropanol, butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. The content of the organic solvent may be 2 to 90% by mass based on the total amount of the alkaline developer.

[0119] The organic solvent developer may contain an organic solvent such as 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. The organic solvent developer may further contain 1 to 20% by mass of water.

[0120] In this step, after removing the unexposed portion, heating at 60 to 250° C. or 0.2 to 10 J / cm 2 The resist pattern 16 is further cured by exposure.

[0121] Then, if Figure 2As shown in FIG. 5 , a wiring layer 17 is formed by performing a plating process, for example, on a portion of the conductor layer 12 where the resist pattern 16 is not formed. The wiring layer 17 may be formed of the same material as the conductor layer 12, or may be formed of a different material. The wiring layer 17 may be, for example, a metal copper layer. The plating process may be one or both of an electroplating process and an electroless plating process.

[0122] Then, if Figure 2 As shown in (f), the resist pattern 16 is removed, and the conductor layer 12 provided at a position corresponding to the resist pattern 16 is removed. Thus, a wiring board 18 having a wiring layer 17 formed on the board can be obtained.

[0123] The resist pattern 16 can be removed by developing by dipping, spraying, or the like using a strong alkaline aqueous solution, for example, a 1-10 mass % sodium hydroxide aqueous solution, a 1-10 mass % potassium hydroxide aqueous solution, or the like.

[0124] The conductor layer 12 can be removed by etching. The etching solution is appropriately selected according to the type of the conductor layer 12, and may be, for example, a cupric chloride solution, a ferric chloride solution, an alkali etching solution, a hydrogen peroxide etching solution, or the like.

[0125] Example

[0126] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0127] <Synthesis of component (A)>

[0128] The monomers shown in Table 1 were mixed with 0.9 parts by mass of azobisisobutyronitrile in the amounts shown in Table 1 (unit: parts by mass) to prepare a solution (a). 0.6 parts by mass of azobisisobutyronitrile was dissolved in 50 parts by mass of a mixed solution (x) of 30 parts by mass of methyl cellosolve and 20 parts by mass of toluene to prepare a solution (b). After 500 g of the mixed solution (x) was put into a flask equipped with a stirrer, a reflux cooler, a thermometer, a dropping funnel and a nitrogen inlet tube, nitrogen was blown into the flask while stirring, and the temperature was raised to 80°C. After the above solution (a) was added dropwise to the above mixed solution in the flask at a constant dropping speed for 4 hours, it was stirred at 80°C for 2 hours. Then, after the above solution (b) was added dropwise to the solution in the flask at a constant dropping speed for 10 minutes, the solution in the flask was stirred at 80°C for 3 hours. Furthermore, the solution in the flask was heated to 95°C over 30 minutes, and after being kept at 95°C for 2 hours, stirring was stopped and cooled to room temperature (25°C) to obtain solutions of binder polymers A-1 to A-3. The non-volatile component (solid content) of the solutions of binder polymers A-1 to A-3 was 49.0% by mass. The weight average molecular weight (Mw), glass transition temperature (Tg) and acid value of binder polymers A-1 to A-3 are shown in Table 1.

[0129] The weight average molecular weight is measured by gel permeation chromatography (GPC) and derived by conversion using a calibration curve of standard polystyrene. The conditions of GPC are as follows.

[0130] (GPC conditions)

[0131] Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd., trade name)

[0132] Pipeline: 3 pipes in total

[0133] Gelpack GL-R420

[0134] Gelpack GL-R430

[0135] Gelpack GL-R440 (the above are product names made by Showa Denko Materials co., Ltd.)

[0136] Eluent: Tetrahydrofuran

[0137] Measurement temperature: 40℃

[0138] Flow rate: 2.05mL / min

[0139] Detector: Hitachi L-3300 RI (manufactured by Hitachi, Ltd., trade name)

[0140] The glass transition temperature was measured using DSC (DSC-7, manufactured by PerkinElmer Co., Ltd.) under the following conditions: a sample amount of 10 mg, a heating rate of 10° C. / min, and a measurement environment of air.

[0141] The acid value is measured by a neutralization titration method based on JIS K0070. First, a solution of the binder polymer is heated at 130°C for 1 hour to remove volatile components to obtain a solid component. Then, after accurately weighing 1 g of the binder polymer of the solid component, 30 g of acetone is added to the binder polymer to uniformly dissolve it, thereby obtaining a resin solution. Next, an appropriate amount of phenolphthalein as an indicator is added to the resin solution, and a neutralization titration is performed using a 0.1 mol / L potassium hydroxide aqueous solution. Then, the acid value is calculated by the following formula.

[0142] Acid value = 0.1 × V × f1 × 56.1 / (Wp × I / 100)

[0143] In the formula, V represents the titration amount (mL) of the 0.1 mol / L potassium hydroxide aqueous solution used for titration, f1 represents the factor (concentration conversion coefficient) of the 0.1 mol / L potassium hydroxide aqueous solution, Wp represents the measured mass of the resin solution (g), and I represents the measured proportion of the non-volatile component in the above resin solution (mass %).

[0144] [Table 1]

[0145]

[0146] [Examples 1 to 9 and Comparative Examples 1 to 3]

[0147] <Preparation of photosensitive resin composition>

[0148] The photosensitive resin compositions were prepared by mixing the components shown in Table 2 in the amounts (parts by mass) shown in Table 2. The amounts (parts by mass) of the components (A) shown in Table 2 are the mass of the non-volatile components (solid content). The details of the components shown in Table 2 are as follows.

[0149] (B) Ingredients

[0150] FA-321M(70): 70% solution of 2,2-bis(4-(methacryloyloxyethoxy)phenyl)propane (ethylene oxide 10 mol adduct on average) in propylene glycol monomethyl ether (manufactured by Showa Denko Materials Co., Ltd.)

[0151] FA-137M: EO-modified trimethylolpropane trimethacrylate (manufactured by Showa Denko Materials Co., Ltd.)

[0152] (C) Ingredients

[0153] BCIM: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (manufactured by Hampford)

[0154] (D) Ingredients

[0155] Coumarin 102: 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0156] (D)'Ingredients

[0157] DBA: 9,10-dibutoxyanthracene (manufactured by KAWASAKI KASEI CHEMICALS LTD.)

[0158] (E) Ingredients

[0159] DIC-TBC-20: 4-tert-butylcatechol (manufactured by DIC Corporation)

[0160] (Other ingredients)

[0161] BHT: 2,6-di-tert-butyl-p-cresol (antioxidant, manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0162] LCV: Colorless crystal violet (manufactured by YAMADA CHEMICAL CO., LTD.)

[0163] SF-808H: A mixture of carboxybenzotriazole, 5-amino-1H-tetrazole, and methoxypropanol (manufactured by SANWAKA SEICORP)

[0164] LA-7RD: 4-TEMPO (manufactured by Asahi Denka Kogyo Kabushiki Kaisha)

[0165] MKG: Malachite green (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.)

[0166] (Solvent)

[0167] TLS: Toluene

[0168] MAL: Methanol

[0169] ACS: Acetone

[0170] <Production of photosensitive elements>

[0171] A polyethylene terephthalate film (manufactured by Teijin Limited, trade name "HTF-01") with a thickness of 16 μm was prepared as a support, and a photosensitive resin composition was applied to the support so that the thickness became uniform, and then dried in a hot air convection dryer at 70°C and 110°C in sequence to form a photosensitive resin layer with a thickness of 25 μm after drying. A polyethylene film (manufactured by TAMAPOLY CO., LTD., trade name "NF-15") was laminated on the photosensitive resin layer as a protective layer to obtain a photosensitive element in which a support, a photosensitive resin layer, and a protective layer were laminated in sequence.

[0172] <Production of laminated body>

[0173] A glass epoxy material, i.e., a copper-clad laminate (substrate, manufactured by ShowaDenko Materials co., Ltd., trade name "MCL-E-679"), in which copper foil (thickness: 35 μm) was laminated on both sides was surface treated using a surface roughening treatment liquid "Mech-Etch Bond CZ-8100" (manufactured by MEC COMPANY LTD., trade name). Then, after water washing, acid washing and water washing, it was dried with an air flow. The surface-treated copper-clad laminate was heated to 80°C, and while peeling off the protective layer, the above-mentioned photosensitive elements were laminated respectively so that the photosensitive resin layer was in contact with the copper surface. Thus, a laminated body in which the copper-clad laminate, the photosensitive resin layer and the support were laminated in this order was obtained. The obtained laminated body was used as a test piece in the test shown below. In addition, lamination was performed using a hot roller at 110°C, a crimping pressure of 0.4 MPa and a roller speed of 1.5 m / min.

[0174] <Evaluation>

[0175] (Measurement of absorbance)

[0176] The absorbance of the photosensitive resin layer was measured using a UV spectrophotometer (Hitachi High-Technologies Corporation, spectrophotometer U-3310). The measurement was performed by placing a photosensitive element with the protective layer peeled off on the measurement side, placing a support film on the reference sample side, continuously measuring to a wavelength of 300 to 700 nm in the absorbance mode, and reading the values ​​at a wavelength of 375 nm and a wavelength of 405 nm. The results are shown in Table 2.

[0177] (Measurement of minimum development time)

[0178] The above-mentioned laminate was cut into 5 cm squares to obtain a test piece for measuring the minimum development time. After peeling off the support from the test piece, the unexposed photosensitive resin layer was spray-developed at a pressure of 0.15 MPa using a 1 mass % sodium carbonate aqueous solution at 30°C, and the shortest time that can visually confirm the removal of the unexposed portion of more than 1 mm was set as the shortest development time. A full cone was used for the nozzle. The distance between the above-mentioned test piece and the tip of the nozzle was 6 cm, and the center of the test piece was configured to coincide with the center of the nozzle. The shorter the minimum development time (unit: seconds), the better the developability. The results are shown in Table 2.

[0179] (Evaluation of Adhesion)

[0180] The photosensitive resin layer of the laminate was exposed (drawn) using a drawing pattern with a line width (L) / space width (S) (hereinafter referred to as "L / S") of 3 / 400 to 30 / 400 (unit: μm) at an energy level of 14 residual steps on a 41-step exposure meter.

[0181] After exposure, the support was peeled off from the laminate to expose the photosensitive resin layer, and a 1 mass % sodium carbonate aqueous solution was sprayed at 30 ° C for 60 seconds to remove the unexposed portion. After development, the minimum value of the line width / space width value in the resist pattern of the line portion (exposed portion) formed by removing the space portion (unexposed portion) without residue and without generating meandering and notch was evaluated for adhesion. The smaller the value, the better the adhesion. The results are shown in Table 2.

[0182] (Evaluation of Resist Pattern Formability)

[0183] The resist pattern with a line width of 10 μm prepared in the above-mentioned adhesion evaluation was observed with a scanning electron microscope, and the shape of the resist pattern and the presence or absence of line thickening were evaluated. The resist pattern shape was evaluated according to the ratio of the top width to the bottom width (bottom width / top width) of the resist pattern according to the following evaluation criteria. The results are shown in Table 2.

[0184] A: The cross-sectional shape is a rectangle (the bottom width / top width is greater than 0.9)

[0185] B: The cross-sectional shape is a small tapered shape (the bottom width / top width is greater than 0.8 and less than 0.9)

[0186] C: The cross-sectional shape is a tapered shape (bottom width / top width is less than 0.8)

[0187] In addition, regarding line thickening, the difference between the designed dimension of the line width in the drawing pattern and the line width (top width) of the formed resist pattern was measured and evaluated based on the following evaluation criteria.

[0188] A: The difference is less than 0.5μm

[0189] B: The difference is greater than 0.5 μm and less than 1.0 μm

[0190] C: The difference is greater than 1.0 μm and less than 2.0 μm

[0191] D: Difference greater than 2.0μm

[0192]

[0193] Explanation of symbols

[0194] 1- photosensitive element, 2- support, 3, 13- photosensitive resin layer, 4- protective layer, 11- insulating layer, 12- conductor layer, 14- mask, 15- active light, 16- resist pattern, 17- wiring layer, 18- wiring substrate.

Claims

1. A photosensitive element comprising a support and a photosensitive resin layer formed on the support using a photosensitive resin composition. The photosensitive resin composition includes a binder polymer having a structural unit based on benzyl (meth)acrylate, a photopolymerizable compound, a photopolymerization initiator, and a coumarin-based sensitizer.

2. The photosensitive element according to claim 1, wherein The content of the coumarin-based sensitizer in the photosensitive resin composition is 0.01 to 0.5 parts by mass relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

3. The photosensitive element according to claim 1, wherein The content of the coumarin-based sensitizer is 0.01 to 0.15 parts by mass relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

4. The photosensitive element according to any one of claims 1 to 3, wherein In the binder polymer, the content ratio of the structural unit based on benzyl (meth)acrylate is 10 to 60% by mass based on the total amount of monomers constituting the binder polymer.

5. The photosensitive element according to any one of claims 1 to 3, wherein The binder polymer has a styrene-based structural unit.

6. The photosensitive element according to claim 5, wherein In the binder polymer, the content of the structural unit derived from styrene is 10 to 50% by mass based on the total amount of monomers constituting the binder polymer.

7. The photosensitive element according to any one of claims 1 to 3, wherein The binder polymer has a structural unit based on an alkyl (meth)acrylate.

8. The photosensitive element according to claim 7, wherein In the binder polymer, the content ratio of the structural unit based on the alkyl (meth)acrylate is 5 to 40% by mass based on the total amount of monomers constituting the binder polymer.

9. The photosensitive element according to any one of claims 1 to 3, wherein The binder polymer has a (meth)acrylic acid-based structural unit.

10. The photosensitive element according to claim 9, wherein In the binder polymer, the content ratio of the structural unit based on (meth)acrylic acid is 10 to 40% by mass based on the total amount of monomers constituting the binder polymer.

11. The photosensitive element according to any one of claims 1 to 3, wherein The photosensitive resin composition contains a polymerization inhibitor.

12. The photosensitive resin composition according to claim 11, wherein The polymerization inhibitor is at least one selected from the following substances: catechol, resorcinol, 1,4-hydroquinone, 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, 3, 5-di-tert-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, 4-tert-butylresorcinol, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, pyrogallol, phloroglucinol, 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-N-oxyl.

13. The photosensitive resin composition according to claim 11, wherein The polymerization inhibitor comprises tert-butylcatechol.

14. The photosensitive element according to claim 11, wherein The content of the polymerization inhibitor in the photosensitive resin composition is 0.003 parts by mass or less relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

15. The photosensitive element according to claim 11, wherein The content of the polymerization inhibitor in the photosensitive resin composition is 0.001 parts by mass or more relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

16. The photosensitive element according to any one of claims 1 to 3, wherein The photosensitive resin composition contains 2,6-di-tert-butyl-p-cresol as an antioxidant.

17. The photosensitive element according to claim 16, wherein The content of the 2,6-di-tert-butyl-p-cresol exceeds 0.002 parts by mass based on 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

18. The photosensitive element according to claim 16, wherein The content of the 2,6-di-tert-butyl-p-cresol is 0.5 parts by mass or less relative to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

19. The photosensitive element according to any one of claims 1 to 3, wherein The photopolymerization initiator contains a 2,4,5-triaryl imidazole dimer.

20. The photosensitive element according to any one of claims 1 to 3, wherein The photopolymerizable compound contains a bisphenol A di(meth)acrylate compound.

21. The photosensitive element according to claim 20, wherein The bisphenol A di(meth)acrylate compound includes 2,2-bis(4-((meth)acryloyloxypentaethoxy)phenyl)propane and / or 2,2-bis(4-((meth)acryloyloxydiethoxy)phenyl)propane.

22. The photosensitive element according to any one of claims 1 to 3, wherein The photosensitive resin composition contains colorless crystal violet.

23. A method for manufacturing a wiring board, comprising: A step of providing a photosensitive resin layer on a substrate using the photosensitive element according to any one of claims 1 to 22; a step of photocuring a portion of the photosensitive resin layer; a step of removing an uncured portion of the photosensitive resin layer to form a resist pattern; and A step of forming a wiring layer on a portion of the substrate where the resist pattern is not formed.

24. A photosensitive element roll comprising a winding core and the photosensitive element according to any one of claims 1 to 22 wound around the winding core.

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