CN113156767A

CN113156767A - Photosensitive resin composition, photosensitive element, method for forming resist pattern, and method for producing printed wiring board

Info

Publication number: CN113156767A
Application number: CN202110189882.0A
Authority: CN
Inventors: 太田绘美子; 村松有纪子; 泽边贤; 冈出翔太; 李相哲
Original assignee: Showa Denko KK
Current assignee: Resonac Holdings Corp
Priority date: 2014-11-17
Filing date: 2015-11-17
Publication date: 2021-07-23
Also published as: JPWO2016080375A1; KR102595962B1; CN107077068A; CN107077068B; JP6690549B2; KR20170085038A; WO2016080375A1; TWI695225B; TW201624131A

Abstract

A photosensitive resin composition comprising: (A) the components: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

Description

Photosensitive resin composition, photosensitive element, method for forming resist pattern, and method for producing printed wiring board

This application is a divisional application of Chinese patent application No.201580060667.3 filed in China at the date of filing PCT/JP2015/082204, 11/17/2015 into China.

Technical Field

The present application relates to a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed wiring board.

Background

In the field of manufacturing printed wiring boards, photosensitive resin compositions are widely used as resist materials for etching treatment or plating treatment. The photosensitive resin composition is often used as a photosensitive element (laminate) having a support and a layer formed on the support using the photosensitive resin composition (hereinafter also referred to as "photosensitive resin composition layer").

The printed wiring board is manufactured as follows, for example. First, a photosensitive element having a support and a photosensitive resin composition layer is prepared, and the photosensitive resin composition layer of the photosensitive element is formed on a substrate for circuit formation (photosensitive layer forming step). Next, after the support is peeled off and removed, a predetermined portion of the photosensitive resin composition layer is irradiated with active light to cure the exposed portion (exposure step). Then, the unexposed portions are removed from the substrate (developed), whereby a resist pattern which is a cured product of the photosensitive resin composition (hereinafter also referred to as "cured resist") is formed on the substrate (developing step). Next, after a circuit is formed on the substrate by performing etching treatment or plating treatment on the substrate on which the resist pattern is formed (circuit forming step), the resist is finally peeled off and removed to manufacture a printed wiring board (peeling step).

As a method of exposure, a method of exposure through a photomask using a mercury lamp as a light source has been conventionally used. In recent years, a Direct writing exposure method has been proposed in which pattern-based Digital data called DLP (Digital Light Processing) or LDI (Laser Direct Imaging) is directly written on a photosensitive resin composition layer without passing through a photomask. This direct writing exposure method is excellent in alignment accuracy and obtains a high-definition pattern as compared with an exposure method via a photomask, and is therefore being introduced for manufacturing a high-density package substrate.

In general, in the exposure step, it is desired to shorten the exposure time in order to improve the production efficiency. However, in the above-described direct writing exposure method, since the substrate is irradiated with the active light while being scanned, in addition to using monochromatic light such as laser light as a light source, a large amount of exposure time tends to be required as compared with a conventional exposure method via a photomask. Therefore, in order to shorten the exposure time and improve the production efficiency, it is necessary to improve the sensitivity (also referred to as "sensitivity") of the photosensitive resin composition compared to the conventional one.

On the other hand, with the recent increase in density of printed wiring boards, there has been an increasing demand for photosensitive resin compositions that can form resist patterns having excellent definition (clarity) and adhesion. Particularly, in the production of a package substrate, a photosensitive resin composition capable of forming a resist pattern having an L/S (line width/space width) of 10/10 (unit: μm) or less is required. Therefore, improvement of the resolution and adhesion even by 1 μm unit is strongly required.

In addition, various photosensitive resin compositions have been studied. Patent document 1 discloses a photosensitive resin composition containing a phenolic compound as a polymerization inhibitor. Further, for example, several compositions have been proposed for photosensitive resin compositions using stable radicals represented by spin traps or nitroxide radical compounds (also referred to as "nitroxyl compounds") (see, for example, patent documents 2 to 5).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2000-162767

Patent document 2: japanese patent laid-open publication No. 2003-140329

Patent document 3: japanese patent laid-open publication No. 2003-215790

Patent document 4: japanese laid-open patent application No. 2006-11397

Patent document 5: japanese laid-open patent publication No. 2007-133398

Disclosure of Invention

Problems to be solved by the invention

However, the photosensitive resin composition described in patent document 1 contains a polymerization inhibitor, which improves the resolution, but on the other hand, the radical polymerization is delayed, and sufficient sensitivity cannot be obtained. The photosensitive resin compositions described in patent documents 2 to 5 may not satisfy the sensitivity, resolution, and adhesion sufficiently in some cases when used as a resist for printed wiring boards. That is, there is still room for improvement in terms of improvement in resolution and adhesion while maintaining sensitivity in resist pattern formation in the conventional photosensitive resin composition.

In addition, the photosensitive resin composition layer for forming a resist pattern is also required to reduce residues (also referred to as "resist sagging" or "sagging edge") at the bottom of the resist. The residue (resist sagging) at the bottom of the resist is generated because the bottom of the resist spreads due to swelling in the developing process and does not peel off from the substrate even by drying. When the plating treatment is performed, if the amount of resist sagging generated is large, the contact area between the plating layer and the substrate becomes small, which becomes a factor of reducing the mechanical strength of the formed circuit. The influence of the resist sweep becomes larger as the circuit formation of the printed wiring board becomes finer, and particularly in the case of forming a circuit having an L/S of 10/10 (unit: μm) or less, if the amount of resist sweep generated is large, the circuit formation itself after plating may become difficult. In addition, when the etching process is performed, if the amount of resist sagging generated is large, the contact area between the etching solution and the substrate becomes small, and it is therefore difficult to form the conductor pattern as designed. In addition, when the etching process is performed, if the amount of resist sweep generation is large, the variation in the width of the conductor pattern becomes large, and the yield may be affected. Therefore, a photosensitive resin composition capable of forming a resist pattern with less resist sag generation is required.

The purpose of the present application is to provide a photosensitive resin composition which can form a resist pattern having excellent resolution and adhesion and reduced resist sag generation with excellent sensitivity, a photosensitive element using the photosensitive resin composition, a method for forming a resist pattern, and a method for producing a printed wiring board.

Means for solving the problems

As a result of intensive studies to solve the above problems, the following were found: a photosensitive resin composition which can form a resist pattern having excellent resolution and adhesion with excellent sensitivity and reduced resist sag generation by combining a binder polymer, a photopolymerizable compound, a2, 4, 5-triarylimidazole dimer or a derivative thereof, and a specific nitroxide radical compound.

That is, one embodiment of the present application provides a photosensitive resin composition comprising: (A) the components: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

The 2,4, 5-triarylimidazole dimer and its derivatives may contain a compound represented by the following general formula (1).

[ formula (1) wherein Ar is¹、Ar²、Ar³And Ar⁴Each independently represents at least one member selected from the group consisting of alkyl groups, alkenyl groups and alkoxy groupsAryl substituted with one of the substituents; x¹And X²Each independently represents a halogen atom, an alkyl group, an alkenyl group or an alkoxy group; p and q each independently represent an integer of 1 to 5. Wherein when p is 2 or more, a plurality of X's are present¹May be the same or different from each other; when q is 2 or more, a plurality of X's are present²May be the same as or different from each other.]

The component (A) may have a structural unit derived from (meth) acrylic acid and a structural unit derived from an alkyl (meth) acrylate.

The photosensitive resin composition according to one embodiment of the present application may further contain a component (E): a phenolic compound.

The photosensitive resin composition according to one embodiment of the present application may further contain a component (F): a sensitizer (also referred to as "sensitizer"), the above-mentioned (F) component containing a pyrazoline compound.

Another embodiment of the present application also provides a photosensitive element having: a support body; and a photosensitive resin composition layer formed on the support and using the photosensitive resin composition. By using such a photosensitive element, a resist pattern having excellent resolution and adhesiveness and reduced resist sweep generation can be efficiently formed with excellent sensitivity.

Another embodiment of the present application also provides a method of forming a resist pattern, including: a photosensitive layer forming step of forming a photosensitive resin composition layer on a substrate using the photosensitive resin composition or the photosensitive element; an exposure step of irradiating an active light beam to at least a part of a region of the photosensitive resin composition layer to photocure the region to form a cured region; and a developing step of removing a region of the photosensitive resin composition layer other than the cured region from the substrate to form a resist pattern as the cured region on the substrate. By this forming method, a resist pattern having excellent resolution and adhesion and reduced resist sweep generation can be efficiently formed with excellent sensitivity.

In the method for forming a resist pattern, the wavelength of the active light to be irradiated may be set to be in the range of 340nm to 430 nm. Thus, a resist pattern having better resolution and adhesion and further reduced resist sweep generation can be formed more efficiently with excellent sensitivity.

Another embodiment of the present application also provides a method for manufacturing a printed wiring board, including a step of performing etching treatment or plating treatment on a substrate on which a resist pattern is formed by the above-described resist pattern forming method. By this manufacturing method, a printed wiring board having a high-density wiring, such as a high-density package substrate, can be efficiently manufactured with excellent precision and good productivity.

Effects of the invention

According to the present application, it is possible to provide a photosensitive resin composition capable of forming a resist pattern having excellent definition and adhesion and reduced resist sweep generation with excellent sensitivity, a photosensitive element using the composition, a method for forming a resist pattern, and a method for producing a printed wiring board.

Drawings

Fig. 1 is a schematic cross-sectional view showing one embodiment of a photosensitive element of the present application.

Fig. 2 is a perspective view schematically showing an example of a process for manufacturing a printed wiring board by the semi-additive process.

Detailed Description

The mode for carrying out the present application will be described in detail below. However, the present application is not limited to the following embodiments. In the present specification, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acrylate means acrylate or methacrylate. The (poly) oxyethylene group means at least one of an oxyethylene group (sometimes referred to as "EO group" or "oxyethylene group") and a polyoxyethylene group in which 2 or more ethylene groups are linked by an ether bond. The (poly) oxypropylene group means at least one of an oxypropylene group (which may be referred to as "PO group" or "oxypropylene group") and a polyoxypropylene group in which 2 or more propylene groups are linked by an ether bond. Further, "EO-modified" refers to a compound having a (poly) oxyethylene group, "PO-modified" refers to a compound having a (poly) oxypropylene group, and "EO-PO-modified" refers to a compound having both a (poly) oxyethylene group and a (poly) oxypropylene group.

In addition, the term "step" in the present specification is not limited to an independent step, and is also included in the term if a desired action of the step is achieved even when the term is not clearly distinguished from other steps. In the present specification, the numerical range represented by "to" means a range including numerical values described before and after "to" as a minimum value and a maximum value, respectively. In the numerical ranges recited in the present specification, the upper limit or the lower limit of a numerical range in a certain stage may be replaced with the upper limit or the lower limit of a numerical range in another stage. In addition, in the numerical ranges described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. In the present specification, the term "layer" includes a structure having a shape formed entirely in a plan view, and also includes a structure having a shape formed partially.

In the present specification, the content of each component in the composition refers to the total amount of a plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition.

< photosensitive resin composition >

The photosensitive resin composition of the present embodiment contains: (A) the components: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure. The photosensitive resin composition may further contain other components as necessary. In the present specification, these components may be simply referred to as component (a), component (B), component (C), component (D), and the like.

By using a photosensitive resin composition containing a binder polymer, a photopolymerizable compound, a photopolymerization initiator containing at least one selected from the group consisting of 2,4, 5-triarylimidazole dimers and derivatives thereof, and a nitroxide free radical compound containing a compound having a2, 2,6, 6-tetramethylpiperidine-1-oxyl structure, a resist pattern having excellent resolution and adhesion with an L/S (line width/space width) of 10/10 (unit: μm) or less and reduced resist run-out can be formed with excellent sensitivity. Among them, it is presumed that the reason why excellent adhesion is obtained and the amount of resist sag generation is reduced is that: by using the photosensitive resin composition, the curing rate at the bottom of the resist pattern is improved, and swelling of the resist pattern is suppressed.

(component (A): Binder Polymer)

Examples of the component (a) include acrylic resins, styrene resins, epoxy resins, amide epoxy resins, alkyd resins, phenol resins, ester resins, urethane resins, epoxy acrylate resins obtained by reaction of an epoxy resin with (meth) acrylic acid, and acid-modified epoxy acrylate resins obtained by reaction of an epoxy acrylate resin with an acid anhydride. These resins may be used alone in 1 kind or in combination of 2 or more kinds. From the viewpoint of more excellent alkali developability and film-forming properties, acrylic resins are preferably used, and among the acrylic resins, acrylic resins containing (a1) a structural unit derived from (meth) acrylic acid (hereinafter also referred to as a (a1) component) and (a2) a structural unit derived from an alkyl (meth) acrylate (hereinafter also referred to as a (a2) component) are more preferably used. Here, the "acrylic resin" refers to a resin mainly having a monomer unit derived from a polymerizable monomer having a (meth) acryloyl group.

The acrylic resin is obtained, for example, by radical polymerization of (meth) acrylic acid, an alkyl (meth) acrylate, and other polymerizable monomers used as needed, as polymerizable monomers (monomers) by a conventional method.

The content of the (a1) structural unit derived from (meth) acrylic acid may be 1 to 99 mass%, 5 to 80 mass%, 10 to 60 mass%, or 15 to 50 mass% based on the total mass (100 mass%, the same applies hereinafter) of the structural units derived from the polymerizable monomer constituting the binder polymer, from the viewpoint of more effectively exhibiting developability and release characteristics.

The alkyl (meth) acrylate (a2) is preferably an alkyl (meth) acrylate having an alkyl group with 1 to 12 carbon atoms, and more preferably an alkyl (meth) acrylate having an alkyl group with 1 to 8 carbon atoms. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 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, undecyl (meth) acrylate, and dodecyl (meth) acrylate. These may be used alone in 1 kind, or 2 or more kinds may be used in any combination.

The content of the structural unit derived from the alkyl (meth) acrylate (a2) may be 1 mass% or more or 2 mass% or more based on the total mass (100 mass%) of the structural units derived from the polymerizable monomer constituting the pressure-sensitive adhesive polymer, from the viewpoint of further improving the peelability. In addition, the content thereof may be 30% by mass or less, 20% by mass or less, or 10% by mass or less, from the viewpoint of further excellent clarity and adhesion.

The acrylic resin may further contain, as a structural unit, another monomer copolymerizable with the component (a1) and/or the component (a 2).

The other monomer copolymerizable with the above-mentioned component (a1) and/or component (a2) is not particularly limited. Examples of the other monomer include benzyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (meth) acrylate derivatives, furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 2,2, 2-trifluoroethyl (meth) acrylate, 2,2, 3, 3-tetrafluoropropyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyloxyethyl (meth) acrylate, cyclohexyloxyethyl (meth) acrylate, adamantyloxyethyl (meth) acrylate, and mixtures thereof, (meth) acrylates such as dicyclopentenyloxypropylethyl (meth) acrylate, and adamantyloxyloxypropylethyl (meth) acrylate; (meth) acrylic acid derivatives such as α -bromoacrylic acid, α -chloroacrylic acid, β -furyl (meth) acrylic acid, and β -styryl (meth) acrylic acid; polymerizable styrene derivatives substituted in the α -position or in the aromatic ring, such as styrene, vinyltoluene, and α -methylstyrene; acrylamides such as diacetone acrylamide; acrylonitrile; ether compounds of vinyl alcohol such as vinyl n-butyl ether; maleic acid; maleic anhydride; maleic acid monoesters such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate; and unsaturated carboxylic acid derivatives such as fumaric acid, cinnamic acid, α -cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. These may be used alone in 1 kind, or 2 or more kinds may be used in any combination.

In addition, from the viewpoint of further reducing resist run-down, the acrylic resin may further have a structural unit derived from styrene or a derivative thereof or a structural unit derived from benzyl (meth) acrylate. From the viewpoint of improving the clarity, the functional group may further have a structural unit derived from benzyl (meth) acrylate.

The content of the structural unit derived from benzyl (meth) acrylate in the acrylic resin may be 3 mass% or more, 5 mass% or more, or 10 mass% or more based on the total mass (100 mass%, the same applies hereinafter) of the structural units derived from the polymerizable monomers constituting the binder polymer, from the viewpoint of more excellent clarity. In addition, the content may be 85 mass% or less, 75 mass% or less, 70 mass% or less, or 50 mass% or less in view of further excellent peelability and adhesiveness.

The acid value of the component (A) may be 90mgKOH/g or more, 100mgKOH/g or more, 120mgKOH/g or more, or 130mgKOH/g or more, from the viewpoint of further shortening the development time. In addition, from the viewpoint of further improving the adhesion of the cured product of the photosensitive resin composition, the acid value may be 250mgKOH/g or less, 240mgKOH/g or less, 235mgKOH/g or less, or 230mgKOH/g or less.

(A) The acid value of the component (a) can be measured as follows. That is, 1g of a binder polymer to be measured for the acid value is referred to as "sample". To the above-mentioned refined binder polymer, 30g of acetone was added and uniformly dissolved. Next, an appropriate amount of phenolphthalein as an indicator was added to the solution, and titration was performed using a 0.1N potassium hydroxide (KOH) aqueous solution. The acid value was determined by calculating the mg number of KOH required for neutralizing the acetone solution of the binder polymer to be measured. When a solution obtained by mixing a binder polymer with a synthetic solvent, a diluting solvent, or the like is used as a measurement target, the acid value is calculated from the following formula.

Acid value of 0.1 × Vf × 56.1/(Wp × I/100)

In the formula, Vf represents the titration amount (mL) of the KOH aqueous solution, Wp represents the mass (g) of the solution containing the measured binder polymer, and I represents the proportion (mass%) of nonvolatile components in the solution containing the measured binder polymer.

When the binder polymer is blended in a mixed state with volatile components such as a synthetic solvent and a diluting solvent, the mixture may be heated at a temperature higher by 10 ℃ or more than the boiling point of the volatile components for 1 to 4 hours before the purification, and the acid value may be measured after the volatile components are removed.

When the weight average molecular weight (Mw) of the component (a) is measured by Gel Permeation Chromatography (GPC) (converted from a calibration curve using standard polystyrene), it may be 200000 or less, 100000 or less, 80000 or less, or 60000 or less, from the viewpoint of further excellent developability. The weight average molecular weight may be 10000 or more, 15000 or more, 20000 or more, or 23000 or more, from the viewpoint of more excellent adhesion.

The degree of dispersion (weight average molecular weight/number average molecular weight) of the component (a) may be 3.0 or less, 2.8 or less, or 2.5 or less, from the viewpoint of further excellent clarity and adhesion.

(A) The component (A) may have a characteristic group which is photosensitive to light having a wavelength in the range of 340 to 430nm in the molecule thereof, as required. Examples of the characteristic group include a group formed by removing at least one hydrogen atom from a sensitizer described later.

From the viewpoint of further improving the formability of the film (photosensitive resin composition layer), the content of the component (a) may be 30 parts by mass or more, 35 parts by mass or more, or 40 parts by mass or more, in 100 parts by mass of the total amount of the component (a) and the component (B). In addition, the content 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 the sensitivity and the clarity.

(component (B): photopolymerizable compound)

As the component (B), a photopolymerizable compound having an ethylenically unsaturated group can be used.

Examples of the compound having an ethylenically unsaturated group include a compound having 1 ethylenically unsaturated group in the molecule, a compound having 2 ethylenically unsaturated groups in the molecule, and a compound having 3 or more ethylenically unsaturated groups in the molecule.

The above-mentioned component (B) preferably contains at least one compound having 2 ethylenically unsaturated groups in the molecule. In the case of containing a compound having 2 ethylenically unsaturated groups in the molecule, the content of the compound may be 5 to 70 parts by mass, 5 to 65 parts by mass, or 10 to 60 parts by mass in 100 parts by mass of the total amount of the components (a) and (B).

Examples of the compound having 2 ethylenically unsaturated groups in the molecule include bisphenol type di (meth) acrylate, hydrogenated bisphenol a type di (meth) acrylate, di (meth) acrylate having a urethane bond in the molecule, EO · PO modified polyalkylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, and the like.

From the viewpoint of further improving the clarity and the peeling property, the above-mentioned component (B) preferably contains at least one selected from bisphenol type di (meth) acrylates, hydrogenated bisphenol a type di (meth) acrylates and EO · PO modified polyalkylene glycol di (meth) acrylates having 2 ethylenically unsaturated groups in the molecule, more preferably contains at least one bisphenol type di (meth) acrylate compound, and still more preferably contains at least one bisphenol type di (meth) acrylate compound having an EO group.

As the bisphenol type di (meth) acrylate, a compound represented by the following general formula (4) can be used.

In the above general formula (4), R²And R³Each independently represents a hydrogen atom or a methyl group. XO and YO each independently represent an EO group or a PO group. (XO)_r1、(XO)_r2、(YO)_s1And (YO)_s2Each represents a (poly) oxyethylene group or a (poly) oxypropylene group. r1, r2, s1 and s2 each independently represent 0 to 40. r1, r2, s1 and s2 represent the number of structural units of the structural unit. Therefore, an integer value is represented in a single molecule, and a rational number as an average value is represented as an aggregate of plural kinds of molecules. The same applies to the number of constituent units in the following description.

In the case where the compound represented by the general formula (4) has a PO group, the total number of the structural units of the PO group in the compound may be 2 or more or 3 or more, from the viewpoint of more excellent resist resolution. From the viewpoint of further excellent developability, the total number of the PO group structural units may be 5 or less.

In the case where the compound represented by the general formula (4) has an EO group, the total number of structural units of the EO group in the compound may be 4 or more, 6 or more, or 8 or more, from the viewpoint of further excellent developability. From the viewpoint of more excellent clarity, the total number of the structural units of the EO group may be 16 or less or 14 or less.

Of the compounds represented by the above general formula (4), 2, 2-bis (4- (methacryloyloxydodecaethoxytetrapropoxy) phenyl) propane is commercially available as FA-3200MY (Hitachi chemical Co., Ltd.), 2, 2-bis (4- (methacryloyloxydiethoxy) phenyl) propane is commercially available as FA-324M (Hitachi chemical Co., Ltd.), 2, 2-bis (4- (methacryloyloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (New Memura chemical Co., Ltd.) or FA-321M (Hitachi chemical Co., Ltd.), and 2, 2-bis (4- (methacryloyloxypentadecyloxy) phenyl) propane is commercially available as BPE-1300 (New Memura chemical Co., Ltd.). These may be used alone in 1 kind, or 2 or more kinds may be used in any combination.

When the photosensitive resin composition contains a bisphenol di (meth) acrylate, the content thereof may be 1 to 65 parts by mass, 5 to 60 parts by mass, or 10 to 55 parts by mass, based on 100 parts by mass of the total amount of the components (a) and (B).

The hydrogenated bisphenol a di (meth) acrylate may be 2, 2-bis (4- (methacryloxypentaethoxy) cyclohexyl) propane. When the photosensitive resin composition contains a hydrogenated bisphenol a di (meth) acrylate, the content thereof may be 1 to 50 parts by mass or 5 to 40 parts by mass based on 100 parts by mass of the total amount of the component (a) and the component (B).

In the EO PO-modified polyalkylene glycol di (meth) acrylate, the (poly) oxyethylene group and the (poly) oxypropylene group in the molecule may be present continuously in blocks or may be present randomly. In the (poly) oxyisopropylidene group, a secondary carbon of the isopropylidene group may be bonded to an oxygen atom, and a primary carbon may be bonded to an oxygen atom.

Examples of commercially available products of EO & PO-modified polyalkylene glycol di (meth) acrylates include those having EO groups: 6 (average) and PO group: 12 (average value) of polyalkylene glycol di (meth) acrylate (Hitachi chemical Co., Ltd., "FA-023M"), having an EO group: 6 (average) and PO group: 12 (average value) of polyalkylene glycol di (meth) acrylate (Hitachi chemical Co., Ltd., "FA-024M"), and the like.

When the photosensitive resin composition contains the EO · PO modified polyalkylene glycol di (meth) acrylate, the content thereof may be 5 to 30 parts by mass or 10 to 20 parts by mass in 100 parts by mass of the total amount of the component (a) and the component (B) from the viewpoint of improving the clarity.

The component (B) may contain at least one photopolymerizable compound having 3 or more ethylenically unsaturated groups in the molecule.

Examples of the compound having 3 or more ethylenically unsaturated groups include trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate (EO-modified product having an oxyethylene structure unit number of 1 to 5), PO-modified trimethylolpropane tri (meth) acrylate, EO-PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate and tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, EO-modified pentaerythritol tetraacrylate, or dipentaerythritol hexa (meth) acrylate. These may be used alone in 1 kind, or in combination of 2 or more kinds.

Tetramethylolmethane triacrylate is commercially available as A-TMM-3 (New Memura chemical industries, Ltd.), EO-modified trimethylolpropane trimethacrylate is commercially available as TMPT21E and TMPT30E (Hitachi chemical industries, Ltd.), pentaerythritol triacrylate is commercially available as SR444(Sartomer Co., Ltd.), dipentaerythritol hexaacrylate is commercially available as A-DPH (New Memura chemical industries, Ltd.), and EO-modified pentaerythritol tetraacrylate is commercially available as ATM-35E (New Memura chemical industries, Ltd.).

In the case where the photopolymerizable compound having 3 or more ethylenically unsaturated groups in the molecule is contained, the content thereof is, from the viewpoint of further improving the definition, adhesion, resist shape and peeling property after curing in a well-balanced manner: the amount of the component (A) and the component (B) may be 3 to 30 parts by mass, 5 to 25 parts by mass, or 5 to 20 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B).

The component (B) may contain a photopolymerizable compound having 1 ethylenically unsaturated group in the molecule, in order to improve the resolution, the adhesiveness, the resist shape, and the peeling property after curing in a well-balanced manner or in order to further suppress the generation of scum.

Examples of the photopolymerizable compound having 1 ethylenically unsaturated group in the molecule include nonylphenoxypolyoxyethylene acrylate, phthalic acid compounds, and alkyl (meth) acrylates. Among the above compounds, nonylphenoxy polyoxyethylene acrylate or phthalic acid compound is preferably contained from the viewpoint of further improving the resolution, adhesion, resist shape and peeling characteristics after curing in a well-balanced manner.

In the case of containing a photopolymerizable compound having 1 ethylenically unsaturated group in the molecule, the content thereof is: the amount of the component (A) and the component (B) may be 1 to 20 parts by mass, 3 to 15 parts by mass, or 5 to 12 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B).

The total content of the component (B) in the photosensitive resin composition is: the amount of the component (A) may be 30 to 70 parts by mass, 35 to 65 parts by mass, or 35 to 60 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B). When the content is 30 parts by mass or more, the sensitivity and the sharpness tend to be further improved. If the content is 70 parts by mass or less, a film (photosensitive resin composition layer) tends to be easily formed, and a good resist shape tends to be easily obtained.

(component (C): photopolymerization initiator)

The photosensitive composition contains a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof as a component (C). The 2,4, 5-triarylimidazole dimer and its derivative may contain a compound represented by the general formula (1) from the viewpoint of further improving sensitivity and adhesion and further reducing the amount of resist run-off.

In the general formula (1), X¹And X²At least one of them is preferably a chlorine atom. At Ar¹、Ar²、Ar³And Ar⁴When each of the aryl groups is independently an aryl group having at least one substituent selected from the group consisting of an alkyl group, an alkenyl group and an alkoxy group, the number of the substituents is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1. In addition, in Ar¹、Ar²、Ar³And Ar⁴When each is independently an aryl group having the above-mentioned substituent, the substitution position is not particularly limited, and is preferably an ortho-position or a para-position. p and q are each independently an integer of 1 to 5, more preferably an integer of 1 to 3, and still more preferably 1.

Examples of the compound represented by the above general formula (1) include 2- (o-chlorophenyl) -4, 5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4, 5-bis (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4, 5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4, 5-diphenylimidazole dimer, and 2- (p-methoxyphenyl) -4, 5-diphenylimidazole dimer. Further, the substituents of the aryl groups of 2,4, 5-triarylimidazoles may be the same and may be given to a symmetric compound, or may be different and may be given to an asymmetric compound. These may be used alone in 1 kind, or in combination of 2 or more kinds.

The component (C) may contain, in addition to the 2,4, 5-triarylimidazole dimer or its derivative, another photopolymerization initiator which is generally used. Examples of the other photopolymerization initiator include aromatic ketones such as benzophenone, N '-tetramethyl-4, 4' -diaminobenzophenone (michler's ketone), 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-acetone-1; quinones such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1, 2-benzoanthraquinone, 2, 3-benzoanthraquinone, 2-phenylanthraquinone, 2, 3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1, 4-naphthoquinone, 9, 10-phenanthrenequinone, 2-methyl-1, 4-naphthoquinone, and 2, 3-dimethylanthraquinone; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; oxime ester compounds such as 1, 2-octanedione-1- [4- (phenylthio) phenyl ] -2- (O-benzoyloxime), 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] ethanone 1- (O-acetyloxime); benzil derivatives such as benzil dimethyl ketal; acridine derivatives such as 9-phenylacridine and 1, 7-bis (9, 9' -acridinyl) heptane; n-phenylglycine, N-phenylglycine derivatives, and the like.

(C) The contents of the components are as follows: the amount of the component (A) may be 0.1 to 10 parts by mass, 1 to 7 parts by mass, 2 to 6 parts by mass, or 3 to 5 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B). When the content of the component (C) is 0.1 parts by mass or more, more favorable sensitivity, resolution or adhesiveness is easily obtained, and the amount of resist sagging generation tends to be further reduced; when the amount is 10 parts by mass or less, a more favorable resist shape tends to be obtained easily.

((D) component: nitroxyl radical Compound)

The nitroxide radical compound refers to a compound having a nitroxide radical. The nitroxide radical can also be said to be a group represented by the following structural formula (5).

(D) The component (A) contains a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure as a nitroxide radical compound. By using the compound having the above structure in combination with at least one selected from the group consisting of 2,4, 5-triarylimidazole dimer and derivatives thereof, a photosensitive resin composition can be obtained which can form a resist pattern having excellent resolution and adhesion with excellent sensitivity and which can reduce the amount of resist run-off.

The compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure can be a compound represented by the following general formula (2). When the photosensitive resin composition contains the compound represented by the following general formula (2), the photosensitive resin composition has good sensitivity, and can further improve the definition and the adhesion of a formed resist pattern and further reduce the generation amount of resist sagging.

[ in the formula (2), R¹Represents a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, an acetylamino group, an amino group, a chloroacetylamino group, a cyano group, a benzoyloxy group or a group represented by the following general formula (3).]

In the formula (3), n1 represents an integer of 1 to 12. ]

In the photosensitive resin composition, the compound represented by the above general formula (2) may be present in a state in which the free radical position is bonded to another compound, an organic group, or the like.

In the general formula (2), R¹Preferably hydroxy, acetylamino or benzoyloxy. If R is¹The hydroxyl group can further reduce the amount of resist sagging. If R is¹The sensitivity can be further improved by using an acetamido group or a benzoyloxy group.

Examples of the compound represented by the general formula (2) include 4-hydroxy-2, 2,6, 6-tetramethylpiperidin-1-yloxy radical, 4-hydroxy-2, 2,6, 6-tetramethylpiperidin-1-yloxybenzoate radical, 4-acetamido-2, 2,6, 6-tetramethylpiperidin-1-yloxy radical, 4-amino-2, 2,6, 6-tetramethylpiperidin-1-yloxy radical, 4- (2-chloroacetamido) -2,2,6, 6-tetramethylpiperidin-1-yloxy radical, 4-cyano-2, 2,6, 6-tetramethylpiperidin-1-yloxy radical and 4-methoxy-2, 2,6, 6-tetramethylpiperidin-1-oxyl radical. These may be used alone in 1 kind, or 2 or more kinds may be used in any combination.

Examples of the other compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure include a2, 2,6, 6-tetramethylpiperidin-1-oxyl radical. This compound can be used in combination with the compound represented by the general formula (2), but is difficult to use alone because of its high volatility.

The component (D) may contain a nitroxide free radical compound other than the compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

The content of the component (D) may be 0.005 to 10 parts by mass, 0.01 to 8 parts by mass, or 0.01 to 5 parts by mass relative to 100 parts by mass of the total amount of the component (A). When the content is 0.005 parts by mass or more, the clearness and the adhesiveness tend to be more excellent; when the content is 10 parts by mass or less, the sensitivity tends to be more excellent. The content of component (D) may be 0.005 to 20 parts by mass, 0.01 to 5 parts by mass, or 0.02 to 1 part by mass based on 100 parts by mass of the total amount of components (A) and (B). When the content is 0.005 parts by mass or more, the clearness and the suppression of the amount of resist sagging tend to be more excellent; when the content is 20 parts by mass or less, the sensitivity tends to be more excellent.

(component (E): a phenolic compound)

From the viewpoint of further improving the clarity, the photosensitive resin composition is more preferably used in combination with the components (a) to (D) and contains at least one phenolic compound. Examples of the component (E) include 2, 2-methylene-bis (4-methyl-6-tert-butylphenol), catechol, picric acid, 4-tert-butylcatechol, 2, 6-di-tert-butyl-p-cresol, 4' -thiobis [ ethylene (oxy) (carbonyl) (ethylene) ] bis [2, 6-bis (1, 1-dimethylethyl) phenol ], and the like.

The content of component (E) may be 0.0001 to 1 part by mass, 0.001 to 0.1 part by mass, or 0.005 to 0.01 part by mass based on 100 parts by mass of the total amount of component (A). When the content is 0.0001 part by mass or more, the clearness and the adhesion tend to be more excellent; when the content is 1 part by mass or less, the sensitivity tends to be more excellent.

The photosensitive resin composition according to one embodiment of the present invention preferably contains, in addition to the above-described components (a) to (E): a sensitizer and/or a (G) component: a hydrogen donor.

(component (F): sensitizer)

The photosensitive resin composition preferably contains at least one sensitizer. The sensitizer is a compound capable of effectively utilizing the absorption wavelength of active light used for exposure, and preferably has a maximum absorption wavelength of 340 to 420 nm.

Examples of the component (F) include pyrazoline compounds, anthracene compounds, acridone compounds, coumarin compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, 1, 2-stilbene compounds, triazine compounds, thiophene compounds, and naphthalimide compounds. In particular, from the viewpoint of further improving the resolution, adhesion, and sensitivity, the (F) component preferably contains a pyrazoline compound or an anthracene compound, and more preferably contains a pyrazoline compound. The sensitizer as the component (F) may be used 1 kind alone or 2 or more kinds in combination.

From the viewpoint of improving sensitivity and clarity in a well-balanced manner, the pyrazoline compound may be a compound represented by the following general formula (6).

In the general formula (6), R represents alkoxy with 1-10 carbon atoms or alkyl with 1-12 carbon atoms, a, b and c independently represent integers of 0-5, and the sum of a, b and c is 1-6. a. When the sum of b and c is 2 to 6, R's in the same molecule may be the same or different.

The R may be linear or branched. Examples of R include, but are not limited to, methoxy, isopropyl, n-butyl, tert-octyl and dodecyl. In addition, the sum of a, b and c in the general formula (6) is 1 to 6, more preferably 1 to 4, and particularly preferably 1 or 2.

From the viewpoint of further improving the sensitivity and solubility, the compound represented by the general formula (6) is preferably a pyrazoline compound in which R is an alkoxy group having 1 to 10 carbon atoms or an alkyl group having 1 to 3 carbon atoms. Among them, 1-phenyl-3- (4-methoxystyryl) -5- (4-methoxyphenyl) pyrazoline is particularly preferable from the viewpoint of improving the ease of synthesis and sensitivity; from the viewpoint of improving the ease of synthesis and solubility in a solvent, 1-phenyl-3- (4-isopropylstyryl) -5- (4-isopropylphenyl) pyrazoline is particularly preferable.

When the photosensitive resin composition contains a pyrazoline compound as the component (F), the effect of improving sensitivity, resolution, and adhesion and the effect of reducing the amount of resist sagging produced by the combination of a2, 4, 5-triarylimidazole dimer or a derivative thereof and a compound having a2, 2,6, 6-tetramethylpiperidine-1-oxyl structure can be further improved. That is, by combining 3 components of 2,4, 5-triarylimidazole dimer or its derivative, a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure, and a pyrazoline compound, extremely good sensitivity, resolution, and adhesion can be obtained, and the amount of resist sag can be greatly reduced.

When the photosensitive resin composition contains the component (F), the content thereof is: the amount of the component (A) may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 3 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B). When the content is 0.01 parts by mass or more, the sensitivity and the resolution are more excellent, and the amount of the resist run-down tends to be further reduced; if the content is 10 parts by mass or less, a more favorable resist shape tends to be obtained easily.

(component (G): hydrogen donor)

The photosensitive resin composition may contain at least one hydrogen donor from the viewpoint of further improving the contrast (also referred to as "image formability") between the exposed portion and the unexposed portion. The hydrogen donor is not particularly limited as long as it can donate hydrogen to the photopolymerization initiator upon reaction of the exposed portion, and examples thereof include bis [4- (dimethylamino) phenyl ] methane, bis [4- (diethylamino) phenyl ] methane, leuco crystal violet, and the like. These may be used alone in 1 kind, or in combination of 2 or more kinds.

In the case where the (G) component is contained, the content thereof is: the amount of the component (A) may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 2 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B). When the content is 0.01 parts by mass or more, more favorable sensitivity tends to be obtained easily. If the content is 10 parts by mass or less, deposition of an excessive (G) component as foreign matter after film formation tends to be suppressed.

(other Components)

The photosensitive resin composition of the present embodiment may contain, if necessary, a photopolymerizable compound (e.g., an oxetane compound) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, a dye such as malachite green, victoria brilliant blue, brilliant green, or methyl violet, a photocolorant such as tribromophenyl sulfone, diphenylamine, benzylamine, triphenylamine, diethylaniline, or 2-chloroaniline, a heat-resistant colorant, a plasticizer such as 4-toluenesulfonamide, a pigment, a filler, an antifoaming agent, a flame retardant, a stabilizer, an adhesion imparting agent, a leveling agent, a peeling accelerator, an antioxidant, a fragrance, an image forming agent, a heat crosslinking agent, and the like. These may be used alone in 1 kind, or in combination of 2 or more kinds. In the case where the photosensitive resin composition contains other components, their contents are preferably: the amount of the component (A) is set to about 0.01 to 20 parts by mass, respectively, based on 100 parts by mass of the total amount of the component (A) and the component (B).

[ solution of photosensitive resin composition ]

The photosensitive resin composition of the present embodiment may further contain at least one organic solvent for adjusting the viscosity, if necessary. Examples of the organic solvent include alcohol solvents such as methanol and ethanol; ketone solvents such as acetone and methyl ethyl ketone; glycol ether solvents such as methyl cellosolve, ethyl cellosolve, and propylene glycol monomethyl ether; aromatic hydrocarbon solvents such as toluene; aprotic polar solvents such as N, N-dimethylformamide and the like. These solvents may be used alone in 1 kind, or 2 or more kinds may be used in combination. The content of the organic solvent contained in the photosensitive resin composition can be appropriately selected according to the purpose and the like. For example, the photosensitive resin composition can be used as a solution having a solid content of about 30 to 60 mass%. Hereinafter, the photosensitive resin composition containing an organic solvent is also referred to as "coating liquid".

The photosensitive resin composition layer can be formed using a photosensitive resin composition by applying (for example, coating) the above-described coating liquid to the surface of a support, a metal plate, or the like described later and drying the coating liquid. The metal plate is not particularly limited and may be appropriately selected according to the purpose and the like. Examples of the metal plate include metal plates containing iron alloys such as copper, copper-containing alloys, nickel, chromium, iron, and stainless steel. The metal plate is preferably a metal plate of copper, a copper-containing alloy, an iron-containing alloy, or the like.

The thickness of the photosensitive resin composition layer to be formed is not particularly limited, and may be appropriately selected according to the use. The thickness of the photosensitive resin composition layer may be, for example, 1 to 100 μm in terms of the thickness after drying. When the photosensitive resin composition layer is formed on the metal plate, the surface of the photosensitive resin composition layer opposite to the metal plate may be covered with a protective layer. Examples of the protective layer include polymer films such as polyethylene and polypropylene.

The photosensitive resin composition can be used for forming a photosensitive resin composition layer of a photosensitive element described later. That is, another embodiment of the present application is a use of a photosensitive resin composition containing: (A) the components: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

The photosensitive resin composition of the present embodiment can be used in a resist pattern forming method described later. That is, another embodiment of the present application is a use of a photosensitive resin composition containing: (A) the components: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

< photosensitive element >

The photosensitive element of one embodiment of the present application includes: a support body; and a photosensitive resin composition layer formed of the photosensitive resin composition and provided on the support. Further, the photosensitive resin composition layer may be a coating film. The coating film referred to in this specification is a coating film in which the photosensitive resin composition is in an uncured state. The photosensitive element may have other layers such as a protective layer, if necessary.

Fig. 1 shows one embodiment of a photosensitive element. In the photosensitive element 1 shown in fig. 1, a support 2, a photosensitive resin composition layer 3 formed of a photosensitive resin composition, and a protective layer 4 are sequentially laminated. The photosensitive element 1 can be obtained, for example, as follows. The photosensitive resin composition layer 3 is formed by applying a coating liquid (i.e., a photosensitive resin composition containing an organic solvent) on the support 2 to form a coating layer and drying the coating layer. Next, the surface of the photosensitive resin composition layer 3 opposite to the support 2 is covered with the protective layer 4, thereby obtaining the photosensitive element 1 of the present embodiment having the support 2, the photosensitive resin composition layer 3 formed on the support 2, and the protective layer 4 laminated on the photosensitive resin composition layer 3. The photosensitive element 1 may not necessarily have the protective layer 4.

As the support, a polymer film made of a polymer having heat resistance and solvent resistance, such as polyester such as polyethylene terephthalate, or polyolefin such as polypropylene or polyethylene, can be used.

The thickness of the support (polymer film) may be 1 to 100 μm, 5 to 50 μm, or 5 to 30 μm. When the thickness of the support is 1 μm or more, breakage of the support can be suppressed when the support is peeled off. Further, by setting the thickness of the support to 100 μm or less, the decrease in the resolution can be suppressed.

The protective layer preferably has a smaller adhesion to the photosensitive resin composition layer than the support. In addition, a film with less fish eyes is preferable. The term "fish eye" refers to a product obtained by incorporating foreign matters, undissolved matters, oxidized and degraded matters of a material into a film when the film is produced by, for example, hot-melting, kneading, extruding, biaxial stretching, or casting the material. That is, "fewer fish eyes" means less foreign matter or the like in the film.

Specifically, as the protective layer, a polymer film made of a polymer having heat resistance and solvent resistance, such as polyester such as polyethylene terephthalate, or polyolefin such as polypropylene or polyethylene, can be used. Commercially available products include polypropylene films such as ALPHAN MA-410 and E-200 of Wangzi paper company, shin-Etsu film company, and PS-series polyethylene terephthalate films such as PS-25 of Kinzman corporation. In addition, the protective layer 4 may be the same as the support body 2.

The thickness of the protective layer may be 1 to 100 μm, 5 to 50 μm, 5 to 30 μm, or 15 to 30 μm. When the thickness of the protective layer is 1 μm or more, the protective layer can be prevented from being damaged when the photosensitive resin composition layer and the support are laminated on the substrate while the protective layer is peeled off. If the thickness of the protective layer is 100 μm or less, the handling property and the low-cost property are excellent.

Specifically, the photosensitive element of the present embodiment can be manufactured, for example, as follows. The method can be produced by a production method comprising the following steps: preparing a component (A): binder polymer, (B) component: a photopolymerizable compound, component (C): a photopolymerization initiator containing at least one member selected from the group consisting of 2,4, 5-triarylimidazole dimers and derivatives thereof, and a component (D): a step of dissolving a nitroxide free radical compound containing a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure in an organic solvent to form a coating solution; a step of applying (for example, coating) the coating liquid on a support to form a coating layer; and drying the coating layer to form a photosensitive resin composition layer.

The solution of the photosensitive resin composition can be applied to the support by a known method such as roll coating, gravure coating, air knife coating, die coating, or bar coating.

The coating layer is not particularly limited as long as it can remove at least a part of the organic solvent from the coating layer, and for example, the coating layer may be dried at 70 to 150 ℃ for 5 to 30 minutes. The amount of the residual organic solvent in the photosensitive resin composition layer after drying may be 2 mass% or less from the viewpoint of preventing the organic solvent from diffusing in the subsequent step.

The thickness of the photosensitive resin composition layer in the photosensitive element can be appropriately selected depending on the application. The thickness of the photosensitive resin composition layer is 1 to 100 μm, 1 to 50 μm or 5 to 40 μm, as represented by the thickness after drying. When the thickness of the photosensitive resin composition layer is 1 μm or more, industrial application is facilitated. When the thickness of the photosensitive resin composition layer is 100 μm or less, the adhesiveness and the resolution tend to be more excellent.

The transmittance of the photosensitive resin composition layer to ultraviolet light was: the ultraviolet ray having a wavelength of 350 to 420nm may be 5 to 75%, 10 to 65%, or 15 to 55%. When the transmittance is 5% or more, more favorable adhesion tends to be easily obtained. When the transmittance is 75% or less, more satisfactory sharpness tends to be easily obtained. Alternatively, the transmittance may be measured using a UV spectrometer. The UV spectrometer may be a model 228A W-beam spectrophotometer manufactured by hitachi corporation.

The photosensitive element may further include intermediate layers such as a buffer layer, an adhesive layer, a light absorbing layer, and a gas barrier layer. As these intermediate layers, for example, the intermediate layers described in japanese patent laid-open No. 2006-098982 can also be applied to one embodiment of the present application.

The photosensitive element of the present embodiment can be preferably used in, for example, a resist pattern forming method described later.

< method for forming resist Pattern >

A resist pattern can be formed by using the photosensitive resin composition or the photosensitive element. The method for forming a resist pattern of the present embodiment includes: (i) a step of forming a photosensitive resin composition layer on a substrate using the photosensitive resin composition or the photosensitive element (photosensitive layer forming step); (ii) a step (exposure step) of irradiating an active light beam to at least a part of a region of the photosensitive resin composition layer to photocure the region to form a cured region; and (iii) a step (developing step) of removing a region other than the cured region of the photosensitive resin composition layer from the substrate to form a resist pattern as the cured region on the substrate. The method for forming a resist pattern may further include other steps as necessary, and the photosensitive resin composition layer in the photosensitive layer forming step may be a coating film. The photosensitive resin composition and the photosensitive element can also be applied to a method for producing a substrate with a resist pattern, which is a method for producing a substrate with a resist pattern by using the method for forming a resist pattern.

(i) Photosensitive layer Forming Process

First, a photosensitive resin composition layer is formed on a substrate using the photosensitive resin composition or the photosensitive element. As the substrate, a substrate (circuit forming substrate) having an insulating layer and a conductor layer formed on the insulating layer can be used.

In the case where the photosensitive element has the protective layer 4, the photosensitive resin composition layer of the photosensitive element is formed on the substrate by, for example, removing the protective layer and then pressing the photosensitive resin composition layer of the photosensitive element against the substrate while heating. In the case of using a photosensitive resin composition, the photosensitive resin composition layer can be formed by applying (e.g., coating) the coating liquid on the surface of the substrate and drying it. In this way, a laminate in which the substrate, the photosensitive resin composition layer, and the support are sequentially laminated was obtained.

From the viewpoint of adhesiveness and tracking property, the photosensitive layer forming step is preferably performed under reduced pressure. The heating of at least one of the photosensitive resin composition layer and the substrate during the pressure bonding is preferably carried out at a temperature of 70 to 130 DEG CPreferably, the pressure is about 0.1 to 1.0MPa (1 to 10 kgf/cm)²Left and right) pressure. These conditions are not particularly limited and are appropriately selected as necessary. Furthermore, if the photosensitive resin composition layer is heated to 70 to 130 ℃, the substrate may not be preheated in advance. By performing the preheating treatment of the circuit-forming substrate, the adhesion and the follow-up property can be further improved.

(ii) Exposure Process

In the exposure step, active light is irradiated to at least a part of the region of the photosensitive resin composition layer formed on the substrate as described above, and the exposed portion irradiated with the active light is photocured to form a latent image. In this case, when the support is present on the photosensitive resin composition layer, the support can be irradiated with the actinic light as long as the support is transparent to the actinic light. On the other hand, in the case where the support exhibits light-shielding properties with respect to the active light, the photosensitive resin composition layer is irradiated with the active light after the support is removed.

As an exposure method, a method called a process pattern (Artwork) in which active light is imagewise irradiated through a negative or positive mask pattern (mask exposure method) is exemplified. Further, a method of irradiating active Light in an image form by a Direct drawing exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method may be employed.

The light source of the active light is not particularly limited, and a known light source can be used. For example, light sources that efficiently emit ultraviolet light, visible light, and the like can be used, such as gas lasers including carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers, solid-state lasers including YAG lasers, semiconductor lasers, and violet lasers including gallium nitride.

The wavelength of the active light (exposure wavelength) is preferably set to be in the range of 340 to 430nm, more preferably 350 to 420nm, from the viewpoint of more reliably obtaining the effects of one embodiment of the present invention.

(iii) Developing process

In the developing step, uncured portions of the photosensitive resin composition layer are removed from the circuit-forming substrate by a developing treatment, thereby forming a resist pattern as a cured product of the photosensitive resin composition layer that is photo-cured on the substrate. When the support is present on the photosensitive resin composition layer, the support is removed, and then the unexposed portion is removed (developed). The development treatment includes wet development and dry development, but wet development is widely used.

In the case of wet development, development is carried out by a known development method using a developer corresponding to the photosensitive resin composition. As the developing method, a dipping method, a spin immersion method, a spraying method, a brush coating method, a slapping method, a wiping method, a shaking dipping method, or the like is used, and a high-pressure spraying method is preferable from the viewpoint of improvement of the resolution. The development may be carried out by combining 2 or more of these methods.

The developer is appropriately selected according to the composition of the photosensitive resin composition. Examples of the developer include an alkaline aqueous solution and an organic solvent developer.

When an alkaline aqueous solution is used as the developer, the developer is safe and stable and has good operability. As the alkali of the alkaline aqueous solution, alkali metal hydroxides such as hydroxides of lithium, sodium or potassium; alkali metal carbonates such as lithium, sodium, potassium, or ammonium carbonates and bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, and borax (sodium tetraborate), sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, 3-propanediol, 1, 3-diamino-2-propanol, morpholine and the like can be used.

As the alkaline aqueous solution used for development, a dilute solution of 0.1 to 5 mass% sodium carbonate, a dilute solution of 0.1 to 5 mass% potassium carbonate, a dilute solution of 0.1 to 5 mass% sodium hydroxide, a dilute solution of 0.1 to 5 mass% sodium tetraborate, and the like are preferable. The pH of the alkaline aqueous solution is preferably set to a range of 9 to 11. In addition, the temperature thereof may be adjusted according to the alkali developability of the photosensitive resin composition layer. The alkaline aqueous solution may contain a surfactant, a defoaming agent, a small amount of an organic solvent for promoting development, and the like.

The basic aqueous solution may contain 1 or more kinds of organic solvents. Examples of the organic solvent to be used include acetone, ethyl acetate, 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. These may be used alone in 1 kind, or in combination of 2 or more kinds. When the organic solvent is contained, the content of the organic solvent is preferably set to 2 to 90% by mass based on the total mass (100% by mass) of the alkaline aqueous solution. The temperature may be adjusted according to the alkali developability. In the alkaline aqueous solution used for the development, a small amount of a surfactant, a defoaming agent, or the like may be mixed.

Examples of the organic solvent used in the organic solvent developer include 1, 1, 1-trichloroethane, N-methylpyrrolidone, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ -butyrolactone. In order to prevent ignition, it is preferable to add water to the organic solvent in an amount of 1 to 20 mass% to prepare an organic solvent developer.

In the method for forming a resist pattern, after removing the unexposed portion, the resist pattern may further comprise heating at 60 to 250 ℃ or at 0.2 to 10J/cm²And (3) exposing the resist pattern to light to cure the resist pattern.

< method for manufacturing printed wiring board >

A method for manufacturing a printed wiring board according to an embodiment of the present application includes the steps of: a substrate having a resist pattern formed on a conductor layer of a substrate (circuit-forming substrate) having an insulating layer and the conductor layer formed on the insulating layer by the above-described method for forming a resist pattern is subjected to etching treatment or plating treatment to form a conductor pattern (may also be referred to as a "circuit pattern"). The method for manufacturing the printed wiring board may include other steps such as a resist removal step, if necessary. The etching treatment or plating treatment of the substrate is performed on a conductor layer of the substrate or the like using the formed resist pattern as a mask.

In the etching treatment, the conductor layer of the circuit-forming substrate, which is not covered with the cured resist, is etched away using a resist pattern (cured resist) formed on the substrate as a mask, thereby forming a conductor pattern. The method of the etching treatment is appropriately selected according to the conductor layer to be removed. Examples of the etching solution include an aqueous solution of copper chloride, an aqueous solution of iron chloride, an alkaline etching solution, and a hydrogen peroxide etching solution. Among these, an aqueous solution of ferric chloride is used in terms of a good etching factor.

On the other hand, in the plating treatment, copper, solder, or the like is plated on the conductor layer of the circuit-forming substrate that is not covered with the cured resist, using the resist pattern (cured resist) formed on the substrate as a mask. After the plating treatment, the cured resist is removed, and the conductor layer coated with the cured resist is etched to form a conductor pattern. The plating treatment may be electrolytic plating or electroless plating. Examples of the plating treatment include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as High through solder plating, Vat bath (nickel sulfate-nickel chloride) plating, nickel plating such as nickel sulfamate, gold plating such as hard gold plating and soft gold plating, and the like.

After the etching treatment and the plating treatment, the resist pattern on the substrate is removed (peeled off). The removal of the resist pattern can be performed, for example, using an aqueous solution that is more strongly alkaline than the alkaline aqueous solution used in the developing step. As the strongly alkaline aqueous solution, a1 to 10 mass% aqueous solution of sodium hydroxide, a1 to 10 mass% aqueous solution of potassium hydroxide, or the like can be used. Among them, 1 to 10 mass% aqueous sodium hydroxide solution or 1 to 10 mass% aqueous potassium hydroxide solution is preferably used, and 1 to 5 mass% aqueous sodium hydroxide solution or 1 to 5 mass% aqueous potassium hydroxide solution is more preferably used. Examples of the method of imparting a strongly basic aqueous solution to the resist pattern include a dipping method and a spraying method, and 1 kind of these may be used alone or 2 or more kinds may be used in combination.

When the resist pattern is removed after the plating treatment, the conductor layer coated with the cured resist is removed by further etching treatment to form a conductor pattern, whereby a desired printed wiring board can be manufactured. The method of the etching treatment is appropriately selected according to the conductor layer to be removed. For example, the above-described etching solution can be applied.

The method for manufacturing a printed wiring board according to one embodiment of the present application is applicable not only to the manufacture of a single-layer printed wiring board but also to the manufacture of a multilayer printed wiring board, and is also applicable to the manufacture of a printed wiring board or the like having a small-diameter through hole.

The photosensitive resin composition of the present embodiment can be preferably used for the production of wiring boards. That is, one of preferred embodiments of one embodiment of the present application is a photosensitive resin composition containing the component (a) in the production of a printed wiring board: a binder polymer; (B) the components: a photopolymerizable compound; (C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and (D) component (A): a nitroxide free radical compound, wherein the component (D) comprises a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

In addition, a more preferable embodiment is that the photosensitive resin composition is applied to the manufacture of a high-density package substrate, and the photosensitive resin composition is applied to a semi-additive process method. An example of a manufacturing process of a wiring board using the semi-additive process method will be described below with reference to the drawings.

In fig. 2 a, a substrate (circuit forming substrate) is prepared in which the conductor layer 10 is formed on the insulating layer 15. The conductive layer 10 is, for example, a metallic copper layer. In fig. 2(b), the photosensitive resin composition layer 32 is formed on the conductor layer 10 of the substrate by the photosensitive layer forming step. In fig. 2(c), the mask 20 is disposed on the photosensitive resin composition layer 32, and the light-cured portion is formed in the photosensitive resin composition layer 32 by irradiating the photosensitive resin composition layer 32 with the active light rays 50 through the above-described exposure step and exposing the region other than the region where the mask 20 is disposed. In fig. 2(d), a region other than the photo-cured portion is removed from the substrate in the photosensitive resin composition layer 32 by a developing process, thereby forming a resist pattern 30 as a photo-cured portion on the substrate. In fig. 2(e), a plating layer 42 is formed on the conductor layer 10 by plating treatment using the resist pattern 30 as a photo-cured portion as a mask. In fig. 2(f), after the resist pattern 30 as a photocured portion is peeled off with an aqueous solution of a strong base, a part of the plating layer 42 and the conductor layer 10 masked with the resist pattern 30 are removed by flash etching to form a conductor pattern 40. The conductive layer 10 and the plating layer 42 may be made of the same material or different materials. Although the method of forming the resist pattern 30 using the mask 20 is described with reference to fig. 2, the resist pattern 30 may be formed by a direct writing exposure method without using the mask 20.

Examples

One embodiment of the present application will be described in more detail below with reference to examples. However, the embodiments of the present application are not limited to the following examples.

Examples 1 to 11 and comparative examples 1 to 7

(preparation of a solution of the photosensitive resin composition)

The photosensitive resin composition solutions of examples 1 to 11 and comparative examples 1 to 7 were prepared by mixing the components (a) to (G) and (O) shown in tables 2 to 4 in the amounts (G unit) shown in these tables with 9G of acetone, 5G of toluene and 5G of methanol. The amounts of the components (A) shown in tables 2 to 4 are the mass of nonvolatile components (solid content). The details of each component shown in tables 2 to 4 are as follows. Further, "-" means no incorporation.

(A) The components: adhesive polymer

[ Synthesis of Binder Polymer (A-1) ]

A solution obtained by mixing 90g of methacrylic acid, 6g of methyl methacrylate, 150 g of styrene, 54g of benzyl methacrylate (mass ratio of 30/2/50/18) and 1.5g of azobisisobutyronitrile as polymerizable monomers (monomers) was set as "solution a".

A solution obtained by dissolving azobisisobutyronitrile in 100g of a mixed solution (mass ratio: 3: 2) of 60g of methylcellosolve and 40g of toluene was designated as "solution b".

300g of a mixture (mass ratio: 3: 2) of 180g of methylcellosolve and 120g of toluene was put into a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen inlet tube, and heated to 80 ℃ while stirring and blowing nitrogen into the flask.

The solution a was added dropwise to the mixture in the flask over 4 hours at a constant dropping rate, and then stirred at 80 ℃ for 2 hours. Then, the solution b was added dropwise to the solution in the flask over 10 minutes at a constant dropping rate, and then the solution in the flask was stirred at 80 ℃ for 3 hours. Further, the temperature of the solution in the flask was raised to 90 ℃ with stirring for 30 minutes, and after stirring at 90 ℃ for 2 hours, the solution was cooled to room temperature, and the stirring was stopped to obtain a solution of the binder polymer (A-1). In the present specification, room temperature means 25 ℃.

The nonvolatile content (solid content) of the adhesive polymer (A-1) was 47.4% by mass, the weight average molecular weight was 44000, the acid value was 196mgKOH/g, and the dispersibility was 1.6.

The weight average molecular weight (Mw) is measured by Gel Permeation Chromatography (GPC) and is derived by conversion into a calibration curve using standard polystyrene. The GPC conditions are shown below.

[ GPC conditions ]

A pump: hitachi L-6000 type (Hitachi, Co., Ltd.)

Column: total 3, column specifications of: 10.7mm phi x 300mm

Gelpack GL-R440

Gelpack GL-R450

Gelpack GL-R400M (from Hitachi Kasei Co., Ltd.)

Eluent: tetrahydrofuran (THF)

Sample concentration: 120mg of a binder polymer solution having NV (nonvolatile content concentration) of 47.4% by mass was collected and dissolved in 5mL of THF to prepare a sample.

Measuring temperature: 40 deg.C

Injection amount: 200 μ L

Pressure: 49Kgf/cm²(4.8MPa)

Flow rate: 2.05 mL/min

A detector: hitachi L-3300 type RI (Hitachi, Co., Ltd.)

[ Synthesis of Binder polymers (A-2) and (A-3) ]

The solutions of the binder polymers (A-2) and (A-3) were obtained in the same manner as in the case of obtaining the solution of the binder polymer (A-1), except that the materials shown in Table 1 as the polymerizable monomers (monomers) were used in the mass ratios shown in the tables. The nonvolatile contents (solid contents) of the binder polymers (A-2) and (A-3) were 47.4% by mass, respectively.

The mass ratio (%) of the polymerizable monomer (monomer), the acid value, the weight average molecular weight and the degree of dispersion of the binder polymers (a-1) to (a-3) are shown in table 1. Further, "-" means no incorporation.

TABLE 1

(B) Composition (I)

B-1: 2, 2-bis (4- (methacryloyloxydiethoxy) phenyl) propane (Hitachi Kasei, "FA-324M")

B-2: 2, 2-bis (4- (methacryloyloxydodecaethoxytetrapropoxy) phenyl) propane (adduct of 12mol in average of ethylene oxide and 4mol in average of propylene oxide) (Hitachi Kasei K.K. 'FA-3200 MY')

B-3: polyoxyalkylene glycol dimethacrylate (Hitachi chemical Co., Ltd., "FA-023M", a compound having both (poly) oxyethylene group (6 mol on average) and (poly) oxypropylene group (12 mol on average) in the molecule)

(C) Ingredient (2,4, 5-triarylimidazole dimer and derivatives thereof)

C-1: 2,2 ' -bis (2-chlorophenyl) -4,4 ', 5,5 ' -tetraphenylbiimidazo [2- (2-chlorophenyl) -4, 5-diphenylimidazole dimer ] (Hampford, "B-CIM")

(photopolymerization initiator other than 2,4, 5-triarylimidazole dimer and its derivative)

C' -2: diphenyl-2, 4, 6-trimethylbenzoylphosphine oxide (Pasteur, "Lucirin TPO")

(D) Composition (I)

D-1: 4-hydroxy-2, 2,6, 6-tetramethylpiperidin-1-oxyl radical (Tokyo Kasei Kogyo)

D-2: 4-hydroxy-2, 2,6, 6-tetramethylpiperidine-1-oxybenzoate radical (Tokyo Kasei Kogyo Co., Ltd.)

D-3: 4-acetamido-2, 2,6, 6-tetramethylpiperidine-1-oxyl radical (Tokyo Kasei Kogyo Co., Ltd.)

(E) Composition (I)

E-1: 4-tert-butylcatechol (DIC corporation, "DIC-TBC")

(F) Composition (I)

F-1: 1-phenyl-3- (4-methoxystyryl) -5- (4-methoxyphenyl) pyrazoline (Nippon chemical industry Co., Ltd.)

F-2: 2, 4-Diethylthiothioxanthone (DETX-S, Nippon Kagaku Co., Ltd.)

F-3: n-methylacridone (Tokyo Kasei Kogyo)

(G) Composition (I)

G-1: leuco crystal violet (Shantian chemical industry Co., Ltd., "LCV")

Other ingredients (dyes)

O-1: malachite green (Osaka organic chemical industry Co., Ltd., "MKG")

TABLE 2

TABLE 3

TABLE 4

< production of photosensitive element >

The solutions of the photosensitive resin compositions obtained above were applied to polyethylene terephthalate films (manufactured by Toray corporation and FB-40) (supports) having a thickness of 16 μm, and dried in sequence using hot air convection dryers at 70 ℃ and 110 ℃ to form photosensitive resin composition layers having a thickness of 25 μm after drying. A polypropylene film (E-200K, King paper Co., Ltd.) (protective layer) was bonded to the photosensitive resin composition layer, and a photosensitive element was obtained in which a support, a photosensitive resin composition layer, and a protective layer were laminated in this order.

< production of laminated substrate >

The photosensitive elements of examples 1 to 11 and comparative examples 1 to 7 were laminated on the copper surface of a substrate after heating a copper-clad laminate (hereinafter referred to as "substrate") composed of a glass fiber epoxy resin material and copper foils (16 μm thick) formed on both surfaces thereof (Hitachi chemical Co., Ltd. "MCL-E-679F") (hereinafter referred to as "substrate") to 80 ℃. The lamination is carried out at a temperature of 120 ℃ and a lamination pressure of 4kgf/cm so that the photosensitive resin composition layer of each photosensitive element is closely adhered to the copper surface of the substrate while removing the protective layer²(0.4 MPa). Subsequently, the substrate was cooled to 23 ℃ to obtain a laminated substrate in which the photosensitive resin composition layer and the support were laminated on the copper surface of the substrate.

< evaluation of sensitivity >

On the support of the obtained laminated substrate, Phototool having 41 steps of optical wedges with a concentration region of 0.00 to 2.00, concentration steps of 0.05, optical wedge sizes of 20mm × 187mm, and step sizes of 3mm × 12mm was closely adhered. The photosensitive resin composition layer was exposed to light through a Phototool and a support using a direct-scanning exposure machine (Hitachi Via Mechanics, Ltd., "DE-1 UH") using a bluish purple laser diode having a wavelength of 405nm as a light source.

After exposure, by passing the beamThe support was peeled from the laminate substrate to expose the photosensitive resin composition layer, and the unexposed portion was removed by spraying a1 mass% aqueous solution of sodium carbonate at 30 ℃ for 60 seconds. In this way, a resist pattern composed of a cured product of the photosensitive resin composition was formed on the copper surface of the substrate. The sensitivity of the photosensitive resin composition was evaluated by measuring the number of remaining steps (number of steps) of the step wedge obtained as a resist pattern (cured film). The sensitivity of the energy amount (unit: mJ/cm) is 14 stages from the number of the above-mentioned stages²) This indicates that the lower the value, the better the sensitivity. If the value is 200mJ/cm²Hereinafter, it can be said that the sensitivity is sufficient. The results are shown in tables 5 to 7.

< evaluation of clarity and adhesion >

A drawing pattern (a drawing pattern for evaluation of sharpness and a drawing pattern for evaluation of adhesion) having a line width (L)/space width (S) (hereinafter referred to as "L/S") of 3/3 to 30/30 (unit: μm) is adhered to a support of the obtained laminated substrate. The drawing pattern for evaluation of sharpness is a drawing pattern in which a gap (drop-out) is formed in a cured product of the photosensitive resin composition. Next, the photosensitive resin composition layer was exposed (drawn) with an energy amount of 14 steps from the remaining number of steps of the 41-step wedge, through a PhotoTool, a drawing pattern, and a support, using the same line drawing exposure machine as that used in the evaluation of sensitivity. After the exposure, the same development treatment as the evaluation of the sensitivity was performed.

After development, the gap portion (unexposed portion) was removed, and the resolution (sharpness) and adhesion were evaluated using the minimum value of the line width/gap width values in the resist pattern formed without meandering and chipping of the line portion (exposed portion). The resolution was evaluated by the minimum value of the gap width, and the adhesion was evaluated by the minimum value of the line width. A smaller value means better clarity and adhesion. The results are shown in tables 5 to 7.

< evaluation of resist sag >

The resist sweep (resist sweep generation amount) was evaluated by observing the line portion of the resist pattern having a line width of 12 μm formed in the evaluation of the above-described definition and adhesion. The resist shape was observed using a Scanning Electron Microscope (SEM) (High-Technologies Corporation, "SU-1500") at an acceleration voltage of 15kV, a magnification of 3000 times, and an inclination angle of 60 degrees, and the resist sag was evaluated according to the following criteria. That is, the maximum value of the sag length generated from the resist side surface and the resist bottom is 0 μm or more and less than 0.5 μm, and is evaluated as "a", and if it is 0.5 μm or more, it is evaluated as "B". In addition, in the case where undercut (under cut) was observed at the bottom of the resist, it was evaluated as "C". The evaluation results are shown in tables 5 to 7.

TABLE 5

TABLE 6

TABLE 7

In addition, the method is as follows: since a resist pattern having a line width of 12 μm could not be formed, evaluation was impossible.

As is clear from tables 5 to 7, the resist patterns formed using the photosensitive resin compositions of examples 1 to 11 containing the binder polymer, the photopolymerizable compound, the photopolymerization initiator containing at least one selected from the group consisting of 2,4, 5-triarylimidazole dimer and derivatives thereof, and the nitroxide free radical compound containing the compound having a2, 2,6, 6-tetramethylpiperidine-1-oxyl structure are excellent in sensitivity, resolution, adhesion, and resist sag reduction. On the other hand, it was difficult to improve all of the sensitivity, the resolution, the adhesion, and the resist run-down reduction performance in comparative examples 1 to 7.

Industrial applicability

The photosensitive resin composition according to one embodiment of the present application can be used as a material for forming a resist pattern for use in the production of a printed wiring board. In particular, the photosensitive resin composition is excellent in sensitivity, resolution, adhesion, and resist sagging reduction, and therefore, is also suitable for use in resist pattern formation for efficiently producing a high-density package substrate with high accuracy and a printed wiring board having a high-density wiring such as a silicon chip rewiring.

Description of reference numerals

1 photosensitive element, 2 support, 3 photosensitive resin composition layer, 4 protective layer, 10 conductor layer, 15 insulating layer, 20 mask, 30 resist pattern, 32 photosensitive resin composition layer, 40 conductor pattern, 42 plating layer.

Claims

1. A photosensitive resin composition comprising:

(A) the components: a binder polymer;

(B) the components: a photopolymerizable compound;

(C) the components: a photopolymerization initiator containing at least one selected from 2,4, 5-triarylimidazole dimers and derivatives thereof; and

(D) the components: a nitroxide free radical compound which is a compound having a nitroxide free radical,

wherein the component (D) contains a compound having a2, 2,6, 6-tetramethylpiperidin-1-oxyl structure.

2. The photosensitive resin composition according to claim 1, wherein the 2,4, 5-triarylimidazole dimer and its derivatives comprise a compound represented by the following general formula (1):

in the formula (1), Ar¹、Ar²、Ar³And Ar⁴Each independently represents at least one substituent which may be selected from the group consisting of alkyl, alkenyl and alkoxyA substituted aryl group; x¹And X²Each independently represents a halogen atom, an alkyl group, an alkenyl group or an alkoxy group; p and q each independently represent an integer of 1 to 5, wherein when p is 2 or more, a plurality of X's are present¹May be the same or different from each other; when q is 2 or more, a plurality of X's are present²May be the same as or different from each other.

3. The photosensitive resin composition according to claim 1 or 2, wherein the component (a) has a structural unit derived from (meth) acrylic acid and a structural unit derived from an alkyl (meth) acrylate.

4. The photosensitive resin composition according to any one of claims 1 to 3, further comprising (E) a component: a phenolic compound.

5. The photosensitive resin composition according to any one of claims 1 to 4, further comprising (F) a component: a sensitizer, the (F) component containing a pyrazoline compound.

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

7. A method for forming a resist pattern, comprising the steps of:

a photosensitive layer forming step of forming a photosensitive resin composition layer on a substrate by using the photosensitive resin composition according to any one of claims 1 to 5 or the photosensitive element according to claim 6;

an exposure step of irradiating a region of at least a part of the photosensitive resin composition layer with an active light beam to photocure the region to form a cured region; and

and a developing step of removing a region other than the cured object region of the photosensitive resin composition layer from the substrate to form a resist pattern, which is the cured object region, on the substrate.

8. The method of forming a resist pattern according to claim 7, wherein the wavelength of the active light is in the range of 340nm to 430 nm.

9. A method for producing a printed wiring board, comprising the step of subjecting a substrate having a resist pattern formed thereon by the method for forming a resist pattern according to claim 7 or 8 to an etching treatment or a plating treatment.