JP5532551B2 - Photosensitive resin composition, photosensitive element, resist pattern forming method and printed wiring board manufacturing method - Google Patents

Description

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

  In the field of manufacturing printed wiring boards, as a resist material used for etching, plating, etc., a photosensitive resin composition or a layer made of this photosensitive resin composition (hereinafter referred to as “photosensitive resin composition layer”) is used. Photosensitive elements (laminates) formed on a support film and having a structure in which a protective film is disposed on a photosensitive resin composition layer are widely used.

  Conventionally, a printed wiring board is manufactured, for example, by the following procedure using the photosensitive element. That is, first, the photosensitive resin composition layer of the photosensitive element is laminated on a circuit forming substrate such as a copper-clad laminate. At this time, the surface opposite to the surface of the photosensitive resin composition layer in contact with the support film (hereinafter referred to as the “lower surface” of the photosensitive resin composition layer) (hereinafter referred to as the “upper surface of the photosensitive resin composition layer”). ") In close contact with the surface of the circuit forming substrate on which the circuit is to be formed.

  Therefore, when a protective film is disposed on the upper surface of the photosensitive resin composition layer, this lamination operation is performed while removing the protective film, and then the photosensitive resin composition layer is heated to the underlying circuit forming substrate. Crimp (normal pressure lamination method).

  Next, pattern exposure is performed through a mask film or the like. At this time, the support film is peeled off at any timing before or after exposure, and then the unexposed portion is dissolved or dispersed and removed with a developer. Next, an etching process or a plating process is performed to form a pattern, and finally the cured portion is peeled and removed.

  Here, the etching treatment is a method of removing a resist after etching away a metal surface not covered with a cured resist formed after development. On the other hand, the plating process is a method in which a metal surface not covered with a hardened resist formed after development is subjected to a plating process such as copper and solder and then the resist is removed and the metal surface covered with the resist is etched. .

  Conventionally, the above-described pattern exposure has been performed through a photomask using a mercury lamp as a light source. However, a direct drawing exposure method in which digital data of a pattern is directly drawn on a resist has been proposed. The direct writing exposure method has been introduced for the production of a high-density package substrate because it has better alignment accuracy than a photomask exposure and can obtain a fine pattern.

  The direct drawing exposure method generally requires a lot of exposure time when using a photosensitive element with the same sensitivity as the conventional exposure method using a mercury lamp as a light source, but it is as much as possible to improve the production throughput. It is required to shorten the exposure time. For this purpose, it is necessary to increase the illuminance on the exposure apparatus side and the sensitivity of the photosensitive element. However, when the conventional photosensitive resin composition is applied to the direct drawing exposure method, the sensitivity, resolution, adhesion, and resist stripping properties are not sufficient.

Therefore, various studies have been made on binder resins, photopolymerization initiators, and the like so far in order to improve the above characteristics (see, for example, Patent Document 1 and Patent Document 2).
JP 2006-234959 A JP 2005-122123 A

  However, when the adhesion is generally improved, the peeling characteristics tend to deteriorate. Even when the photosensitive resin compositions described in Patent Documents 1 and 2 are used, the required sensitivity, resolution, adhesion, and resist peeling characteristics are required. There is still room for improvement from the viewpoint of satisfying all of the above.

  Accordingly, the present invention provides a photosensitive resin composition that is excellent in sensitivity, resolution, and adhesion, and can obtain a resist pattern having sufficient peeling characteristics, a photosensitive element using the same, a method for forming a resist pattern, and printed wiring It aims at providing the manufacturing method of a board.

In the method for forming a photosensitive element and a resist pattern according to the present invention, (A) a divalent group represented by at least one of the following general formulas (I), (II), and (III) or (IV): A divalent group represented by the following general formula (I) on the basis of the total mass of the binder polymer: (B) a photopolymerizable compound, and (C) a photopolymerization initiator. 10 to 60% by mass, a divalent group represented by the following general formula (II) is 10 to 70% by mass, and a divalent group represented by at least one of the following general formula (III) or (IV) The photosensitive resin composition which is 5-60 mass% is used .

［式（Ｉ）、（ＩＩ）、（ＩＩＩ）及び（ＩＶ）中、Ｒ^１、Ｒ^２、Ｒ^４及びＲ^６はそれぞれ独立に水素原子又はメチル基を示し、Ｒ^３、Ｒ^５及びＲ^７はそれぞれ独立に炭素数１〜３のアルキル基又はアルコキシ基、ＯＨ基、ハロゲン原子を示し、ｋは０〜５の整数を示し、ｍ及びｎはそれぞれ独立に０〜３の整数を示す。ｋ、ｍ及びｎが２以上の場合、複数存在するＲ^３、Ｒ^５及びＲ^７は、それぞれ同一であっても異なっていてもよい。］

[In the formulas (I), (II), (III) and (IV), R ¹ , R ² , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ³ , R ⁵ and R ⁷ Each independently represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group, an OH group, or a halogen atom, k represents an integer of 0 to 5, and m and n each independently represents an integer of 0 to 3. When k, m and n are 2 or more, a plurality of R ³ , R ⁵ and R ⁷ may be the same or different from each other. ]

  The present inventors include a binder polymer in which the binder polymer (A) has a specific structure as represented by the general formula (III) and / or (IV), and the specific component as described above. In combination, the photosensitive resin composition of the present invention can obtain a good resist shape with high sensitivity, high resolution, and high adhesion, and form a resist pattern with even better release characteristics. The present invention has been found.

  In the present invention, it is preferable that (C) the photopolymerization initiator contains a hexaarylbiimidazole derivative. Thereby, the sensitivity of the photosensitive resin composition is increased, and the resolution and adhesion are further improved.

  Moreover, this invention provides a photosensitive element provided with a support film and the photosensitive resin composition layer which consists of said photosensitive resin composition formed on this support film.

  The photosensitive element of the present invention can improve the sensitivity, resolution and adhesion in a well-balanced manner by providing the photosensitive resin composition layer comprising the photosensitive resin composition of the present invention, so that the resist pattern can be formed in a good shape. can do.

  The present invention also includes a laminating step of laminating the photosensitive resin composition layer composed of the photosensitive resin composition of the present invention on a circuit forming substrate, and an active ray at a predetermined portion of the photosensitive resin composition layer. There is provided a resist pattern forming method comprising an exposure step of irradiating and photocuring an exposed portion, and a developing step of removing a portion other than the exposed portion of the photosensitive resin composition layer from the substrate.

  According to the method for forming a resist pattern of the present invention, since the photosensitive resin composition layer comprising the photosensitive resin composition of the present invention is used, a good resist shape can be obtained even by a direct drawing exposure method with a short exposure time. It is possible to efficiently form a resist pattern having

  The present invention further provides a method for producing a printed wiring board, in which a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern of the present invention is etched or plated.

  According to the method for producing a printed wiring board of the present invention, since the resist pattern is formed by the resist pattern forming method of the present invention, the printed wiring board can be efficiently produced and the density of the wiring is high. Can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin composition which can obtain the resist pattern which is excellent in a sensitivity, the resolution, and adhesiveness, and has sufficient peeling characteristics, the photosensitive element using this, the formation method of a resist pattern, and printed wiring A method for manufacturing a plate can be provided.

  Hereinafter, embodiments of the present invention will be described in detail. In the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid, (meth) acrylate means acrylate or a corresponding methacrylate, and (meth) acryloyl group means acryloyl group or methacryloyl group. means.

(Photosensitive resin composition)
First, the photosensitive resin composition of the present invention will be described. The photosensitive resin composition of the present invention comprises (A) a binder polymer having a divalent group represented by at least one of the following general formulas (I), (II), and (III) or (IV): B) contains a photopolymerizable compound and (C) a photopolymerization initiator.

［式（Ｉ）、（ＩＩ）、（ＩＩＩ）及び（ＩＶ）中、Ｒ^１、Ｒ^２、Ｒ^４及びＲ^６はそれぞれ独立に水素原子又はメチル基を示し、Ｒ^３、Ｒ^５及びＲ^７はそれぞれ独立に炭素数１〜３のアルキル基又はアルコキシ基、ヒドロキシル基、ハロゲン原子を示し、ｋは０〜５の整数を示し、ｍ及びｎはそれぞれ独立に０〜３の整数を示す。ｋ、ｍ及びｎが２以上の場合、複数存在するＲ^３、Ｒ^５及びＲ^７は、それぞれ同一であっても異なっていてもよい。

[In the formulas (I), (II), (III) and (IV), R ¹ , R ² , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ³ , R ⁵ and R ⁷ Each independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, a hydroxyl group, or a halogen atom, k represents an integer of 0 to 5, and m and n each independently represents an integer of 0 to 3. When k, m and n are 2 or more, a plurality of R ³ , R ⁵ and R ⁷ may be the same or different from each other.

  First, the binder polymer as component (A) will be described. The component (A) includes at least a structural unit represented by the general formula (I), a structural unit represented by the general formula (II), and a structural unit represented by the general formula (III) or (IV). And a binder polymer containing one kind.

In the general formula (I), R ¹ represents a hydrogen atom or a methyl group, and is preferably a methyl group. The polymerizable monomer forming the structural unit of the general formula (I) is a structural unit based on acrylic acid or methacrylic acid.

  The content of the structural unit of the above general formula (I) from the viewpoint of the peeling property, developability, resolution and adhesion of the resist to the circuit forming substrate of the photosensitive resin composition layer comprising the photosensitive resin composition as a constituent material Is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, and more preferably 20 to 40% by mass based on the total mass (solid content) of component (A). Further preferred is 25 to 35% by mass.

  When the content of the structural unit of the general formula (I) is less than 10% by mass, the alkali solubility is inferior, the peel piece tends to be large, and the peel time tends to be long. When the content exceeds 60% by mass, The resolution tends to decrease.

In the general formula (II), R ² represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom. R ³ represents an alkyl group having 1 to ³ carbon atoms, an alkoxy group, an OH group, or a halogen atom. k is an integer of 0 to 5, and when k is 2 or more, a plurality of R ³ may be the same or different. Examples of the polymerizable monomer that forms the structural unit of the general formula (II) include styrene or a styrene derivative, or α-methylstyrene or an α-methylstyrene derivative. In the present invention, the term “styrene derivative” and “α-methylstyrene derivative” means that the hydrogen atom in the benzene ring of styrene is a substituent R ³ (an alkyl group or alkoxy group having 1 to ³ carbon atoms, an OH group, a halogen atom). An atom or the like).

  Further, from the viewpoint of improving both adhesion and peeling properties, the content of the structural unit of the general formula (II) is 5 to 70% by mass based on the total mass (solid content) of the component (A). Is more preferable, 10 to 65% by mass is more preferable, 15 to 60% by mass is further preferable, and 20 to 60% by mass is particularly preferable.

  When the content of the structural unit of the general formula (II) is less than 5% by mass, the resolution tends to be inferior. When the content exceeds 70% by mass, the peeled piece becomes large and the peeling time tends to be long. is there.

In the general formula (III) and the general formula (IV), R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and each is preferably a methyl group. R ⁵ and R ⁷ each independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, an OH group, or a halogen atom. m and n are each independently an integer of 0 to 3, and when m and n are 2 or more, a plurality of R ⁵ and R ⁷ may be the same or different.

Examples of the polymerizable monomer that forms the structural unit of the general formula (III) include tetrahydrofurfuryl (meth) acrylate or tetrahydrofurfuryl derivative of (meth) acrylic acid, and polymerization that forms the structural unit of the general formula (IV). Examples of the polymerizable monomer include furfuryl (meth) acrylate or a furfuryl (meth) acrylate derivative. In the present invention, the “(meth) acrylic acid tetrahydrofurfuryl derivative” means that the five-membered hydrogen atom of tetrahydrofurfuryl (meth) acrylate is a substituent R ⁵ (an alkyl group having 1 to 3 carbon atoms). Or an alkoxy group, an OH group, a halogen atom or the like), and “(meth) acrylic acid furfuryl derivative” is a five-membered hydrogen atom having an unsaturated bond of (meth) acrylic acid furfuryl. And a substituent R ⁷ (an alkyl group having 1 to 3 carbon atoms or an alkoxy group, an OH group, a halogen atom, etc.).

  In addition, from the viewpoint of improving both adhesion and peeling properties, the content of the structural unit of the general formula (III) and / or the structural unit of the general formula (IV) is the total mass of the component (A) ( 5 to 60% by mass, preferably 10 to 55% by mass, more preferably 15 to 50% by mass, and particularly preferably 15 to 40% by mass, based on the solid content). preferable.

  When the content of the structural unit of the general formula (III) and / or the structural unit of the general formula (IV) is less than 5% by mass, the peeling piece tends to be large and the peeling time tends to be long. When the amount exceeds 60% by mass, the resolution tends to be inferior.

  As the binder polymer described above, one type of binder polymer may be used alone, or two or more types of binder polymers may be used in any combination. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymerization components (including different repeating units as constituent components), two or more types of binders having different weight average molecular weights Examples thereof include polymers and two or more types of binder polymers having different degrees of dispersion. In addition, a polymer having a multimode molecular weight distribution described in JP-A No. 11-327137 can also be used.

  The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the binder polymer can be measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene). According to this measurement method, the Mw of the binder polymer is preferably 5,000 to 300,000, more preferably 10,000 to 150,000, further preferably 20,000 to 100,000, and particularly preferably 30,000 to 70,000. preferable. When Mw is less than 5000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  The (A) binder polymer preferably has a dispersity (Mw / Mn) of 1.0 to 3.0, and more preferably 1.0 to 2.0. When the degree of dispersion exceeds 3.0, the adhesion and resolution tend to decrease.

  The (A) binder polymer may be used in combination with a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, an alkyd resin, or a phenol resin.

  The (A) binder polymer of the present invention can be produced, for example, by radical polymerization of a polymerizable monomer.

  Moreover, (A) binder polymer of this invention can also use together polymerizable monomers other than the polymerizable monomer for comprising the said general formula (I)-(IV). Examples of the polymerizable monomer other than the polymerizable monomer for constituting the general formulas (I) to (IV) include (meth) acrylic acid alkyl ester, and the like. Examples of the ester include compounds represented by the following general formula (V).

^{_{CH 2 = C (R 8)}} -COOR 9 (V)
[Wherein, R ⁸ represents a hydrogen atom or a methyl group, and R ⁹ represents an alkyl group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms substituted with a hydroxyl group, an epoxy group, a halogen atom, or the like. A valent organic group. ]

Examples of the compound represented by the general formula (V) in which the substituent R ⁹ is an alkyl group having 1 to 12 carbon atoms include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meta ) Acrylic acid propyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic Acid 2-ethylhexyl ester, (meth) acrylic acid nonyl ester, (meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester, 2-hydroxyethyl, 2-hydroxypropyl, 3 -Hydroxypropyl, 4-hydroxybutyl and the like . These may be used alone or in any combination of two or more.

  In addition, acrylamide such as diacetone acrylamide, vinyl alcohol esters such as acrylonitrile and vinyl-n-butyl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid Glycidyl ester, maleic acid, maleic anhydride, maleic acid monoester such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiol An acid etc. are mentioned. These may be used alone or in any combination of two or more.

  (A) The acid value of the binder polymer is preferably 30 to 400 mgKOH / g, more preferably 50 to 350 mgKOH / g, preferably 70 to 300 mgKOH / g, and 100 to 250 mgKOH / g. It is preferable that it is 150 to 200 mgKOH / g. When the acid value is less than 30 mg KOH / g, the development time tends to be long, and when it exceeds 400 mg KOH / g, the developer resistance of the photocured resist tends to be lowered. Moreover, when performing solvent image development as a image development process, it is preferable to prepare the polymerizable monomer which has a carboxyl group in a small quantity.

  Further, (A) the binder polymer may have a characteristic group having photosensitivity in its structure, if necessary. The content of the (A) binder polymer is preferably 30 to 70 parts by weight, preferably 35 to 65 parts by weight, based on 100 parts by weight of the total amount of the components (A) and (B). More preferred is 40-60 parts by weight. When the content is less than 30 parts by weight, there is a tendency that good film formability cannot be obtained when the photosensitive element is used, and when it exceeds 70 parts by weight, good sensitivity and resolution tend not to be obtained.

  Next, the photopolymerizable compound as the component (B) will be described.

  (B) As the photopolymerizable compound, for example, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol, a bisphenol A-based (meth) acrylate compound, a glycidyl group-containing compound with α, β- Compounds obtained by reacting unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule, nonylphenoxypolyalkyleneoxyacrylate, phthalic acid compounds, (meth) acrylic acid alkyl esters, etc. Can be mentioned. These may be used alone or in combination of two or more.

  The component (B) includes a photopolymerizable compound having one polymerizable ethylenically unsaturated bond in the molecule and two or more polymerizable ethylenes in the molecule from the viewpoint of obtaining the effects of the present invention more reliably. It is preferable to use in combination with a photopolymerizable compound having a polymerizable unsaturated bond.

  The photopolymerizable compound having one polymerizable ethylenically unsaturated bond in the molecule preferably includes nonylphenoxypolyalkyleneoxyacrylate, and includes nonylphenoxypolyethyleneoxyacrylate from the viewpoint of shortening the peeling time. It is preferable.

  In addition, as the photopolymerizable compound having two or more polymerizable ethylenically unsaturated bonds in the molecule, α, β-unsaturation is added to polyhydric alcohol from the viewpoint of further improving sensitivity, resolution and adhesion. It is preferable to include a compound obtained by reacting a carboxylic acid and / or a bisphenol A (meth) acrylate compound.

  Examples of the nonylphenoxypolyethyleneoxyacrylate include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethylene Examples include oxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate. These may be used alone or in any combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 2 propylene groups. 14 polypropylene glycol di (meth) acrylate, polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO, PO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate. These are used alone or in combination of two or more. Here, “EO” represents ethylene oxide, and an EO-modified compound represents one having a block structure of an ethylene oxide group. “PO” represents propylene oxide, and a PO-modified compound has a propylene oxide group block structure.

  Examples of the bisphenol A-based (meth) acrylate compound include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane and the like It is done. Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynona) Toxi) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane and the like.

  2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is either BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name) or FA-321M (manufactured by Hitachi Chemical Co., Ltd., product name). ) And 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). It is available. The number of ethylene oxide groups in one molecule of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably 4-20, and more preferably 8-15. . These may be used alone or in any combination of two or more.

  Examples of the (meth) acrylate compound having a urethane bond in the molecule include, for example, a (meth) acryl monomer having an OH group at the β-position and a diisocyanate compound (isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate). , 1,6-hexamethylene diisocyanate, etc.), tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate Etc. Examples of the EO-modified urethane di (meth) acrylate include UA-11 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). Examples of the EO and PO-modified urethane di (meth) acrylate include UA-13 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). These are used alone or in combination of two or more.

  Examples of the phthalic acid compounds include γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate. Etc. These may be used alone or in any combination of two or more.

  Moreover, it is preferable that (B) component contains the polyalkylene glycol di (meth) acrylate which has both an ethylene glycol chain and a propylene glycol chain in a molecule | numerator from a viewpoint which can improve the flexibility of a cured film. This polyalkylene glycol di (meth) acrylate is not particularly limited as long as it has both an ethylene glycol chain and a propylene glycol chain (n-propylene glycol chain or isopropylene glycol chain) as an alkylene glycol chain in the molecule. . In addition to ethylene glycol chain and propylene glycol chain, n-butylene glycol chain, isobutylene glycol chain, n-pentylene glycol chain, hexylene glycol chain, structural isomers thereof and the like having about 4 to 6 carbon atoms. It may have an alkylene glycol chain.

  When there are a plurality of ethylene glycol chains and propylene glycol chains, the plurality of ethylene glycol chains and propylene glycol chains need not be continuously present in blocks, and may be present randomly. In the isopropylene glycol chain, the secondary carbon of the propylene group may be bonded to an oxygen atom, or the primary carbon may be bonded to an oxygen atom.

  The alkylene glycol chain in the molecule of the polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule is, for example, a compound represented by the following general formula (VI), the following general formula The compound represented by (VII), the compound represented by the following general formula (VIII), etc. are mentioned.

［式中、Ｒ^１０及びＲ^１１は、各々独立に水素原子又はメチル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^１＋ｍ^２（平均値）は１〜３０の整数であり、ｎ^１は１〜３０の整数である。］

[Wherein, R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or a methyl group, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ¹ + m ² (average value) is 1 to 30 N ¹ is an integer of ¹ to 30. ]

［式中、Ｒ^１２及びＲ^１３は各々独立に水素原子又はメチル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^３は１〜３０の整数であり、ｎ^２＋ｎ^３（平均値）は１〜３０の整数である。］

[Wherein, R ¹² and R ¹³ each independently represent a hydrogen atom or a methyl group, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, m ³ is an integer of 1 to 30, n ² + N ³ (average value) is an integer of 1 to 30. ]

［式中、Ｒ^１４及びＲ^１５は各々独立に水素原子又はメチル基を示し、ＥＯはエチレングリコール鎖を示し、ＰＯはプロピレングリコール鎖を示し、ｍ^４及びｎ^４は各々独立に１〜３０の整数である。］

[Wherein, R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or a methyl group, EO represents an ethylene glycol chain, PO represents a propylene glycol chain, and m ⁴ and n ⁴ each independently represents 1 to 30. It is an integer. ]

The total number of repeating ethylene glycol chains (m ¹ + m ² , m ³ and m ⁴ ) in the general formulas (VI), (VII) and (VIII) is an integer of 1 to 30, and the resist shape is From the viewpoint of making it better, it is preferably an integer of 1 to 15, more preferably an integer of 2 to 12, and particularly preferably an integer of 4 to 8.

The total number of repeating propylene glycol chains (n ¹ , n ² + n ³ and n ⁴ ) in the above general formulas (VI), (VII) and (VIII) is each independently an integer of 1 to 30, and the resolution From the viewpoint of making the ratio more favorable, it is preferably an integer of 2 to 20, more preferably an integer of 4 to 16, and further preferably an integer of 6 to 14.

Specific examples of the compound represented by the general formula (VI) include, for example, vinyl having R ¹⁰ = R ¹¹ = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value). And compounds (trade name FA-023M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the compound represented by the general formula (VII) include, for example, vinyl having R ¹² = R ¹³ = methyl group, m ³ = 6 (average value), and n ² + n ³ = 12 (average value). And compounds (trade name FA-024M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the compound represented by the general formula (VIII) include, for example, a vinyl compound in which R ¹⁴ = R ¹⁵ = hydrogen atom, m ⁴ = 1 (average value), and n ⁴ = 9 (average value) ( Shin-Nakamura Chemical Co., Ltd., sample name NK ester HEMA-9P) and the like. These may be used alone or in combination of two or more.

  As content of the photopolymerizable compound of (B) component, it is preferable to set it as 30-70 weight part on the basis of 100 weight part of total amounts of (A) component and (B) component, 35-65 weight part More preferably, it is 40-60 parts by weight. If the content is less than 30 parts by weight, good sensitivity and resolution tend not to be obtained, and if it exceeds 70 parts by weight, good film formability tends not to be obtained when producing a photosensitive element. . Each is used alone or in combination of two or more.

  Next, as the photopolymerization initiator as the component (C), for example, 4,4′-bis (diethylamino) benzophenone, benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone— Aromatic ketones such as 1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoin, alkylbenzoin Benzoin compounds such as benzyl dimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole 2-mer, 2- (o-fluorophenyl) -4,5 2,4,5 such as diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer -Acridine derivatives such as -triarylimidazole dimer, 9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane, and the like.

  Further, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may be the same to give the target compound, or differently give an asymmetric compound. From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. These are used alone or in combination of two or more.

  As content of the photoinitiator of (C) component, it is preferable to set it as 0.1-10 weight part with respect to 100 weight part of total amounts of (A) component and (B) component, 2-6 weight part More preferably, the content is 3 to 5 parts by weight. If this content is less than 0.1 parts by weight, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by weight, a good resist shape tends not to be obtained. Each is used alone or in combination of two or more.

  The sensitizing dye of component (D) in the present invention can effectively utilize the absorption wavelength of the active light to be used. As the sensitizing dye, a compound having a maximum absorption wavelength of 370 nm to 420 nm is preferable. In the present invention, by using such a sensitizing dye, it becomes possible to have a sufficiently high sensitivity to the exposure light of the direct drawing exposure method. If the maximum absorption wavelength of the sensitizing dye is less than 370 nm, the sensitivity to direct drawing exposure light tends to decrease, and if it is 420 nm or more, the stability tends to decrease even in a yellow light environment.

  Examples of the sensitizing dye (D) of the present invention include pyrazolines, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, and thiophenes. And naphthalimides.

  (D) The content of the sensitizing dye is preferably 0.01 to 10 parts by weight, and 0.05 to 5 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B). More preferably, the content is 0.1 to 2 parts by weight. If this amount is less than 0.01 part by weight, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by weight, a good shape tends not to be obtained. Each is used alone or in combination of two or more.

  Examples of (E) amine compounds include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leucocrystal violet.

  (E) The content of the amine compound is preferably 0.01 to 10 parts by weight, and 0.05 to 5 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B). More preferably, the content is 0.1 to 2 parts by weight. If the blending amount is less than 0.01 parts by weight, good sensitivity tends not to be obtained, and if it exceeds 10 parts by weight, there is a tendency to deposit as foreign matter after film formation. These may be used alone or in combination of two or more.

  If necessary, the photosensitive resin composition may include a photopolymerizable compound (such as 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, Photochromic agents such as bromophenylsulfone and leucocrystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion promoters, leveling agents , A peeling accelerator, an antioxidant, a fragrance, an imaging agent, a thermal crosslinking agent, and the like can be contained in an amount of about 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of component (A) and component (B). . These are used alone or in combination of two or more.

  The photosensitive resin composition of the present invention is dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof. It is good also as a solution about 30-60 mass% of solid content. This solution can be used as a coating solution for forming the photosensitive resin composition layer of the photosensitive element.

  In addition, the above coating solution may be used for forming a photosensitive resin composition layer of a photosensitive element by coating and drying on a support film described later, for example, the surface of a metal plate, for example, Apply a liquid resist on the surface of an iron-based alloy such as copper, copper-based alloy, nickel, chromium, iron, stainless steel, preferably copper, copper-based alloy, iron-based alloy, and dry, and then coat the protective film It may be used.

  Moreover, although the layer thickness of the photosensitive resin composition layer changes with uses, it is preferable that it is about 1-100 micrometers by the thickness after drying. In the case where the above-described liquid resist is used after being coated with a protective film, examples of the protective film include polymer films such as polyethylene and polypropylene.

(Photosensitive element)
Next, the photosensitive element of the present invention will be described. The photosensitive element of this invention has a support film and the photosensitive resin composition layer formed on a support film at least.

  FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. The photosensitive element 1 shown in FIG. 1 has a structure in which a photosensitive resin composition layer 3 is laminated on a support 2. The photosensitive resin composition layer 3 is a layer made of the above-described photosensitive resin composition of the present invention. In the photosensitive element 1, you may coat | cover the surface on the opposite side to the support body side of the photosensitive resin composition layer 3 with the protective film 4 as needed.

  As the support film 2, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used.

  The support film (polymer film) 2 preferably has a thickness of 1 to 100 μm. If the thickness is less than 1 μm, the support film tends to be broken when the support film is peeled off before development, and if it exceeds 100 μm, the resolution tends to decrease. From this viewpoint, 5 to 25 μm is preferable. One polymer film is used as a support for the photosensitive resin composition layer, and the other is used as a protective film 4 for the photosensitive resin composition, laminated on both sides of the photosensitive resin composition layer 3. May be.

  The protective film 4 preferably has a smaller adhesive strength between the photosensitive resin composition layer and the protective film than the adhesive strength between the photosensitive resin composition layer and the support film, and is preferably a low fisheye film.

  "Fish eye" means that when a material is melted by heat, kneaded, extruded, biaxially stretched, casting method, etc., foreign materials, undissolved materials, oxidized degradation products, etc. It is taken in.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used.

  Examples of commercially available products include, for example, Oji Paper Co., Ltd., trade name: Alphan MA-410, E-200C, Shin-Etsu Film Co., Ltd., polypropylene film, Teijin Limited, trade name: PS-25, PS series. Examples thereof include, but are not limited to, polyethylene terephthalate films.

  The protective film preferably has a thickness of 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. If the thickness is less than 1 μm, the protective film tends to be broken during lamination, and if it exceeds 100 μm, the cost tends to be inferior.

  The photosensitive resin composition layer is prepared by dissolving the photosensitive resin composition of the present invention in a solvent as described above to obtain a solution (coating solution) having a solid content of about 30 to 60% by mass, and then applying the solution (coating solution). (Liquid) is preferably applied on a support film and dried.

  The coating can be performed by a known method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater. Moreover, drying can be performed at 70-150 degreeC and about 5 to 30 minutes. The amount of the remaining organic solvent in the photosensitive resin composition is preferably 2% by mass or less from the viewpoint of preventing the organic solvent from diffusing in the subsequent step.

  Moreover, although the thickness of the photosensitive resin composition layer 3 changes with uses, it is preferable that it is 1-100 micrometers in the thickness after drying, and it is more preferable that it is 1-50 micrometers. If the thickness is less than 1 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the effect of the present invention is reduced, and the adhesive force and resolution tend to decrease.

  Moreover, it is preferable that the transmittance | permeability with respect to the ultraviolet-ray with a wavelength of 365 nm is 5 to 75%, as for the photosensitive resin composition layer, it is more preferable that it is 7 to 60%, and it is further more preferable that it is 10 to 40%. If the transmittance is less than 5%, the adhesion tends to be inferior, and if it exceeds 75%, the resolution tends to be inferior. The transmittance can be measured by a UV spectrometer, and examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  The photosensitive element of the present invention may further have an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer. Moreover, the obtained photosensitive element 1 can be wound up and stored in a roll shape around a sheet shape or a core. In addition, it is preferable to wind up so that a support film may become the outermost side in this case. Examples of the core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

  An end face separator is preferably installed on the end face of the roll-shaped photosensitive element roll from the viewpoint of end face protection, and a moisture-proof end face separator is preferably installed from the viewpoint of edge fusion resistance.

  Moreover, as a packing method, it is preferable to wrap and package in a black sheet with low moisture permeability.

(Method for forming resist pattern)
Next, a resist pattern forming method according to the present invention will be described. The resist pattern forming method according to the present invention includes a lamination step of laminating a photosensitive resin composition layer composed of the above-described photosensitive resin composition on a circuit forming substrate, and a predetermined portion of the photosensitive resin composition layer. It has an exposure process which irradiates actinic light and photocures an exposure part, and the image development process which removes parts other than the exposure part of the photosensitive resin composition layer from a board | substrate. The “circuit forming substrate” refers to a substrate including an insulating layer and a conductor layer formed on the insulating layer.

  In the laminating process, as a method of laminating the photosensitive resin composition layer on the circuit forming substrate, after removing the protective film, the photosensitive resin composition layer is formed while heating the photosensitive resin composition layer. For example, a method of laminating by press-bonding to the substrate is used. Specifically, the protective film of the photosensitive element of the present invention described above is gradually peeled from the photosensitive resin composition layer, and at the same time, the portion of the surface of the photosensitive resin composition layer gradually exposed, A photosensitive resin composition layer is laminated on the circuit forming substrate by bringing the circuit forming substrate into close contact with the surface on which the circuit is to be formed. In addition, it is preferable to laminate | stack this operation under pressure reduction from the viewpoint of adhesiveness and followable | trackability.

In the lamination of the photosensitive element, the photosensitive resin composition layer and / or the circuit forming substrate is preferably heated to 70 to 130 ° C., and the pressure bonding pressure is about 0.1 to 1.0 MPa (1 to 10 kgf / cm). it is preferably about ^2), but not particularly limited to these conditions.

  Further, if the photosensitive resin composition layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate in advance, but in order to further improve the laminating property, Pre-heat treatment of the substrate can also be performed.

  In a subsequent exposure step, as a method for forming an exposed portion, a method of irradiating an active ray on an image through a negative or positive mask pattern called an artwork (mask exposure method) can be mentioned.

  At this time, when the support film present on the photosensitive resin composition layer is transparent to the active light, the active light can be irradiated through the support film, and when the support film is light-shielding After removing the support film, the photosensitive resin composition layer is irradiated with actinic rays. Alternatively, a method of irradiating active rays in an image form by a direct drawing method such as a laser direct drawing exposure method or a DLP (Digital Light Processing) exposure method may be employed.

  As a light source of actinic light, known light sources such as carbon arc lamps, mercury vapor arc lamps, high pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid state lasers such as YAG lasers, ultraviolet rays such as semiconductor lasers, visible light, etc. That effectively radiate are used.

  Subsequently, after exposure, as a method for removing portions other than the exposed portion in the development step, first, when the support film is present on the photosensitive resin composition layer, the support film is removed, and then wet. Examples include a method in which a portion other than the exposed portion is removed by development, dry development, or the like. Thereby, a resist pattern is formed.

  For example, in the case of wet development, using a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, an organic solvent developer, etc., for example, spraying, rocking immersion, brushing, scraping, etc. Development is performed by a known method.

  As the developing solution, a safe and stable solution having good operability such as an alkaline aqueous solution is used. Examples of the base of the alkaline aqueous solution include alkali metal hydroxides such as lithium, sodium, and potassium hydroxides, alkali metal carbonates such as lithium, sodium, and potassium carbonates or bicarbonates, or alkali metal bicarbonates. Salts, ammonium carbonates or bicarbonates, alkali metal phosphates such as potassium phosphate and sodium phosphate, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used.

  Moreover, as alkaline aqueous solution used for image development, 0.1-5 mass% dilute solution of sodium carbonate, 0.1-5 mass% dilute solution of potassium carbonate, 0.1-5 mass% dilute solution of sodium hydroxide, A dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred.

  Moreover, it is preferable to make pH of the alkaline aqueous solution used for image development into the range of 9-11, and the temperature is adjusted according to the developability of the photosensitive resin composition layer. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.

  Examples of the aqueous developer include a developer composed of water or an alkaline aqueous solution and one or more organic solvents. Here, as the base of the alkaline aqueous solution, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, Examples include 3-propanediol, 1,3-diaminopropanol-2, morpholine and the like. Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer.

  The pH of the developer is desirably as small as possible within a range where the resist can be sufficiently developed, and is preferably pH 8-12, more preferably pH 9-10.

  Examples of the organic solvent include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and the like. It is done. These may be used alone or in combination of two or more. The concentration of the organic solvent is usually preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability.

  Examples of the organic solvent-based developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. These organic solvents preferably add water in the range of 1 to 20% by mass in order to prevent ignition.

  Moreover, you may use together 2 or more types of image development methods as needed. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and the high pressure spray method is most suitable for improving the resolution.

As the treatment after development, the resist pattern may be further cured and used by heating at about 60 to 250 ° C. or exposure at an exposure amount of about 0.2 to 10 J / cm ² as necessary.

  For the etching of the metal surface performed after development, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or the like can be used.

(Printed wiring board manufacturing method)
Next, the manufacturing method of the printed wiring board which becomes this invention is demonstrated. The method for producing a printed wiring board according to the present invention comprises etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern of the present invention.

  Etching and plating of the circuit forming substrate is performed on a conductor layer or the like of the circuit forming substrate using the formed resist pattern as a mask. Etching solutions used for etching include cupric chloride solution, ferric chloride solution, alkaline etching solution, hydrogen peroxide etching solution, etc., and among these, chloride chloride is used because of its good etch factor. It is preferable to use a diiron solution.

  Moreover, as a plating method in the case of plating, for example, copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high throw solder plating, watt bath (nickel sulfate-nickel chloride) plating, nickel sulfamate, etc. Nickel plating, hard gold plating, and gold plating such as soft gold plating.

  After completion of the etching or plating, the resist pattern can be peeled off with a stronger alkaline aqueous solution than the alkaline aqueous solution used for development, for example. As this strongly alkaline aqueous solution, for example, a 1 to 10% by mass sodium hydroxide aqueous solution, a 1 to 10% by mass potassium hydroxide aqueous solution and the like are used.

  Examples of the peeling method include a dipping method and a spray method, and the dipping method and the spray method may be used alone or in combination. The printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board or may have a small diameter through hole.

  By using the photosensitive resin composition and the photosensitive element of the present invention, through the above series of steps, forming a resist pattern, and etching or plating the circuit-formed substrate on which the resist pattern is formed as described above, In particular, in the laser direct drawing method, the production efficiency is extremely high and a printed wiring board can be manufactured.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all. In the following description, evaluation of “resolution adhesion” means evaluation of whether both resolution and adhesion are compatible.

[Synthesis of Binder Polymer (A-1)]
To a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet tube, 450 g of propylene glycol monomethyl ether and toluene in a mass ratio of 3: 2 are added, and stirred while blowing nitrogen gas. And heated to 80 ° C. On the other hand, 150 g of methacrylic acid, 175 g of furfuryl methacrylate and 175 g of styrene and 9.0 g of azobisisobutyronitrile (hereinafter referred to as “solution a”) were prepared as copolymerization monomers. The solution a was added dropwise to the above blend of propylene glycol monomethyl ether and toluene having a mass ratio of 3: 2 heated to 80 ° C. over 4 hours, and then kept at 80 ° C. for 2 hours with stirring. Further, a solution prepared by dissolving 1.2 g of azobisisobutyronitrile in 100 g of a propylene glycol monomethyl ether and toluene mixture having a mass ratio of 3: 2 was dropped into the flask over 10 minutes. The solution after dropping was kept at 80 ° C. for 3 hours with stirring, and then heated to 90 ° C. over 30 minutes. The mixture was kept at 90 ° C. for 2 hours and then cooled to obtain a binder polymer A-1.

The nonvolatile content (solid content) of the binder polymer (A-1) was 47.8% by mass, and the weight average molecular weight was 40,000. The weight average molecular weight was measured by a gel permeation chromatography method and was derived by conversion using a standard polystyrene calibration curve. The GPC conditions are shown below.
(GPC conditions)
Pump: Hitachi L-6000 type [manufactured by Hitachi, Ltd.]
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) (above, manufactured by Hitachi Chemical Co., Ltd., trade name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd.]

[Synthesis of Binder Polymers (A-2) to (A-7)]
Binder polymers A-2 to A-7 were synthesized in the same manner as A-1 with the composition of the comonomer shown in Table 1.

  The above binder polymers (A-1) to (A-7) and the following materials are blended in the mass ratio shown in Table 2 (the component (A) is a solid content), and Examples 1 to 5 and Comparative Examples Solutions of the photosensitive resin compositions 1 and 2 were prepared.

(B) Photopolymerizable compound (B-1): FA-321M (manufactured by Hitachi Chemical Co., Ltd., trade name); 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane)
(B-2): FA-024M (trade name, manufactured by Hitachi Chemical Co., Ltd.); in the compound represented by the general formula (VII), R ¹² = R ¹³ = methyl group, m ³ = 6 (average value) , N ² + n ³ = 12 (average value) compound (B-3): M-114 (trade name, manufactured by Toagosei Co., Ltd.); 4-normalnonylphenoxyoctaethylene glycol acrylate (C) photopolymerization initiator ( C-1): BCIM (trade name, manufactured by Hampford); 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole (D) Sensitizing dye: DBA ( Kawasaki Kasei Kogyo Co., Ltd., trade name); 9,10-dibutoxyanthracene (E) Color former (amine compound): Leuco Crystal Violet

  Next, the photosensitive resin composition solution was uniformly applied onto a 16 μm thick polyethylene polyethylene terephthalate film (manufactured by Teijin Ltd., product name “HTF-01”), and hot air convection at 70 ° C. and 110 ° C. The photosensitive element was obtained by drying with a drier. The film thickness of the photosensitive resin composition layer was 25 μm. Subsequently, a protective film (manufactured by Tamapoly Co., Ltd., product name “NF-15”) was laminated on the photosensitive resin composition layer by roll pressing.

  On the other hand, the copper surface of a copper clad laminate (made by Hitachi Chemical Co., Ltd., trade name MCL-E-67), which is a glass epoxy material laminated with copper foil (thickness 35 mm) on both sides, is a brush equivalent to # 600. Polishing was performed using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and then dried with an air flow to obtain a copper clad laminate (substrate).

Then, after heating to a copper clad laminate 80 ° C., while removing the protective film of each photosensitive element (Examples 1 to 5 and Comparative Examples 1 and 2) on the copper clad laminate, The resin composition layer was laminated (laminated) under a pressure of 4 kgf / cm ² at 120 ° C. so that the resin composition layer was in close contact with the surface of the copper-clad laminate.

  Next, when the copper clad laminate on which each photosensitive element is laminated is cooled to 23 ° C., the polyethylene terephthalate surface has a concentration region of 0.00 to 2.00, a concentration step of 0.05, and a tablet size. A phototool having a 41-step tablet having a length of 20 mm × 187 mm and a size of each step of 3 mm × 12 mm was adhered.

  Using a direct drawing machine DE-1AH manufactured by Hitachi Via Mechanics Co., Ltd. using a 405 nm blue-violet laser diode as a light source, drawing was performed at a predetermined exposure amount, and the number of remaining step steps after development of the 41-step tablet was obtained. . Further, a drawing pattern having a line width / space width of 6/6 to 22/22 (unit: mm) was used, and the minimum dimension at which resolution contact was obtained after development was defined as the resolution. More specifically, a photosensitive resin is used with a predetermined exposure amount and a support film using a drawing pattern having a line width / space width of 6/6 to 22/22 (unit: μm) on the test piece. The composition layer was exposed (drawn). Thereafter, the unexposed portion can be removed cleanly by development processing, and the line is formed without meandering and chipping. The line width and the space width are equal, and the smallest value of the line width / space width. Was used to evaluate resolution and adhesion. The smaller the numerical value, the better the resolution and adhesion. Table 4 shows the obtained results.

Next, the polyethylene terephthalate film was peeled off, and a 1% by mass sodium carbonate aqueous solution was sprayed at 30 ° C. for 24 seconds to remove unexposed portions. Thereafter, the sensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet of the photocured film formed on the copper-clad laminate. The results are shown in Table 4 below. The sensitivity is indicated by the number of steps of the step tablet. The higher the number of steps of the step tablet, the higher the sensitivity. More specifically, the number of remaining steps when exposed at 70 mJ / cm ² is shown as sensitivity. The illuminance was measured using an ultraviolet illuminometer (trade name: “UIT-150” manufactured by USHIO INC.) To which a 405 nm probe was applied.

  The resist shape after development was observed using a Hitachi scanning electron microscope S-500A. The resist shape is preferably close to a rectangle.

  For the peelability, a photocured film having a size of 40 mm × 50 mm was prepared under the conditions shown in Table 3, and peeling was performed using a 3% by mass aqueous sodium hydroxide solution. The time when the film finished peeling from the substrate was defined as the peeling time. Moreover, the size of the peeling piece after peeling completion was observed visually (S; it shows that a peeling piece is small).

  As shown in Table 4, in the compositions of Examples 1 to 5, the resolution (L / S) is as good as 9 to 12 μm, the peeling time is moderately short, the peeling piece size is small, and the resolution and adhesion The peelability was balanced. On the other hand, in Comparative Examples 1 and 2, although the peelability was good, the resolution and adhesion were poor.

  As described above, according to the photosensitive resin composition of the present invention, the peeling time is moderately short and the resist shape obtained after photocuring can be maintained well, so that a resist pattern can be efficiently formed and further printed. It becomes possible to improve the production efficiency of a wiring board.

It is a schematic cross section which shows suitable one Embodiment of the photosensitive element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 2 ... Support film, 3 ... Photosensitive resin composition layer, 4 ... Protective film.

Claims (5)

Comprising a support film, and the support film made of photosensitive photosensitive resin composition formed on the photosensitive resin composition layer, a
The photosensitive resin composition comprises (A) a binder polymer having a divalent group represented by at least one of the following general formulas (I), (II), and (III) or (IV):
(B) a photopolymerizable compound, and
(C) comprising a photopolymerization initiator,
Based on the total mass of the binder polymer, the divalent group represented by the following general formula (I) is 10 to 60% by mass, and the divalent group represented by the following general formula (II) is 10 to 70% by mass. %, The photosensitive element whose divalent group represented by at least 1 type of the following general formula (III) or (IV) is 5-60 mass% .

[In the formulas (I), (II), (III) and (IV), R ¹ , R ² , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ³ , R ⁵ and R ⁷ Each independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, a hydroxyl group, or a halogen atom, k represents an integer of 0 to 5, and m and n each independently represents an integer of 0 to 3. When k, m and n are 2 or more, a plurality of R ³ , R ⁵ and R ⁷ may be the same or different from each other. ] The photosensitive element according to claim 1, wherein the (C) photopolymerization initiator contains a hexaarylbiimidazole derivative. A circuit forming board, a lamination step of laminating the photosensitive resin composition layer composed of a photosensitive light-sensitive resin composition,
An exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an actinic ray to photocure an exposed portion;
Have a, a developing step of removing portions other than the exposed portion of the photosensitive resin composition layer from the substrate,
The photosensitive resin composition comprises (A) a binder polymer having a divalent group represented by at least one of the following general formulas (I), (II), and (III) or (IV):
(B) a photopolymerizable compound, and
(C) comprising a photopolymerization initiator,
Based on the total mass of the binder polymer, the divalent group represented by the following general formula (I) is 10 to 60% by mass, and the divalent group represented by the following general formula (II) is 10 to 70% by mass. %, The formation method of the resist pattern whose divalent group represented by at least 1 type of the following general formula (III) or (IV) is 5-60 mass% .

[In the formulas (I), (II), (III) and (IV), R ¹ , R ² , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ³ , R ⁵ and R ⁷ Each independently represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group, a hydroxyl group, or a halogen atom, k represents an integer of 0 to 5, and m and n each independently represents an integer of 0 to 3. When k, m and n are 2 or more, a plurality of R ³ , R ⁵ and R ⁷ may be the same or different from each other. ] The method for forming a resist pattern according to claim 3 , wherein the (C) photopolymerization initiator contains a hexaarylbiimidazole derivative. A method for manufacturing a printed wiring board, comprising etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 3 .

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