JP5046019B2 - Photosensitive resin composition, photosensitive element using the same, 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 using the same, a method for forming a resist pattern, and a method for producing a printed wiring board.

In the field of manufacturing printed wiring boards, as a resist material used for etching and plating, a photosensitive resin composition and a layer containing the photosensitive resin composition (hereinafter referred to as “photosensitive resin composition layer”). A photosensitive element (laminate) having a structure in which is formed on a support film and a protective film is disposed on the photosensitive resin composition layer is widely used.
The printed wiring board is manufactured by the following procedure, for example, 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”). Is laminated so as to be in close contact with the surface on which the circuit is to be formed. At that time, when a protective film is arranged on the upper surface of the photosensitive resin composition layer, this lamination operation is performed while peeling the protective film, and the photosensitive resin composition layer is thermocompression bonded to the underlying circuit forming substrate. (Normal pressure laminating 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. Thereafter, 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 etching away a metal surface not covered with a hardened 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, a mercury lamp has been mainly used as a light source for the above pattern exposure. However, the light from mercury lamps contains ultraviolet rays that are harmful to the human body, causing problems in work safety. There is also an exposure method using a visible light laser as a light source, but this method requires a resist sensitive to visible light, and this resist has to be handled in a dark room or under a red lamp.
In view of the above problems, actinic rays obtained by cutting 99.5% of light emitted from a mercury lamp light source using a filter with a wavelength of 365 nm or less have been proposed. In recent years, gallium nitride blue laser light sources that oscillate light having a wavelength of 405 nm and have a long life and high output have been proposed.
On the other hand, as a new exposure technique, a direct drawing exposure method called DLP (Digital Light Processing) in which digital data of a pattern is directly drawn on a resist has recently been proposed (for example, see Non-Patent Document 1). This direct drawing exposure method has been introduced for the production of a high-density package substrate because it has better alignment accuracy than exposure through a photomask and a fine pattern can be obtained. Moreover, as a light source, the active light source which cut 99.5% using the filter for the light below wavelength 365nm among the light emitted from a blue laser light source or a mercury lamp light source can be used.

Electronics Packaging Technology, June 2002 (p.74-79)

However, since the conventional photosensitive element is designed to exhibit optimum photosensitive characteristics with respect to full-wavelength exposure of a mercury lamp light source centered on light having a wavelength of 365 nm, light centered on a wavelength of 405 nm (non-light Activity obtained by cutting 99.5% or more of light having a wavelength of 365 nm or less out of light emitted from a light source of a mercury laser from a semiconductor laser including those described in Patent Document 1 and light emitted from a mercury lamp light source. When the pattern exposure is intended to be performed using a light beam), the sensitivity of the photosensitive element with respect to light having a wavelength of 400 nm or more is low, so that the throughput (productivity per unit time) is low and sufficient resolution is achieved. And a good resist shape could not be obtained.
The present invention has been made in view of the above-described problems. When a resist pattern is formed by exposure light having a wavelength of 400 to 440 nm, the photosensitivity capable of obtaining sufficient sensitivity, resolution, and good resist shape. It is an object to provide a photosensitive resin composition, a photosensitive element using the same, a method for forming a resist pattern, and a method for producing a printed wiring board.

One of the causes of the low sensitivity of the conventional photosensitive element with respect to light having a wavelength of 400 to 440 nm is that the optical density of the photosensitive element with respect to the wavelength region is small, that is, the light in the wavelength region is sufficient. It was found that the photopolymerization of the photopolymerizable compound having a polymerizable ethylenically unsaturated bond (B) in the photosensitive element could not be efficiently initiated.
Then, the present inventors have found that the above problem can be solved by constituting a photosensitive resin composition containing a specific amount of a specific photosensitizer, and have completed the present invention.
That is, the present invention provides [1] (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated bond, (C) a photoradical polymerization initiator, (D) It is related with the photosensitive resin composition containing the compound represented by Formula (1).

［一般式（１）中、Ｒ^１及びＲ²は、それぞれ独立に、水素原子、炭素数１〜２０のアルキル基、炭素数５〜１２のシクロアルキル基、炭素数１〜１２のアルコキシ基、フェニル基、ベンジル基、炭素数２〜１２のアルカノイル基又はベンゾイル基を示す。Ｒ³、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９及びＲ^１０はそれぞれ独立に水素原子、炭素数１〜１２のアルキル基、ハロゲン原子、シアノ基、カルボキシル基、フェニル基、炭素数２〜６のアルコキシカルボニル基又はベンゾイル基を示す。前記炭素数１〜２０のアルキル基は、アルキル基の炭素数が２〜１２の場合、主鎖炭素原子間に酸素原子を有してもよく、水酸基で置換されてもよい。前記炭素数５〜１２のシクロアルキル基は、環の中に酸素原子を有してもよく、水酸基で置換されてもよい。前記Ｒ^１及びＲ²中の前記フェニル基は、炭素数１〜６のアルキル基、水酸基、ハロゲン原子、シアノ基、カルボキシル基、フェニル基、炭素数１〜６のアルコキシ基、フェノキシ基、及び炭素数２〜６のアルコキシカルボニル基からなる群より選ばれる１種以上の基及び／又は原子で置換されてもよい。前記ベンジル基は、炭素数１〜６のアルキル基、水酸基、ハロゲン原子、シアノ基、カルボキシル基、フェニル基、炭素数１〜６のアルコキシ基、フェノキシ基、及び炭素数２〜６のアルコキシカルボニル基からなる群より選ばれる１種以上の基及び／又は原子で置換されてもよい。前記ベンゾイル基は、炭素数１〜６のアルキル基、水酸基、ハロゲン原子、シアノ基、カルボキシル基、フェニル基、炭素数１〜６のアルコキシ基、フェノキシ基、及び炭素数２〜６のアルコキシカルボニル基からなる群より選ばれる１種以上の基及び／又は原子で置換されてもよい。］
また、本発明は、［２］上記感光性樹脂組成物の（Ｄ）一般式（１）で表される化合物は、Ｒ^１又はＲ^２がそれぞれ水素原子又は炭素数１〜６のアルキル基を示し、Ｒ^３〜Ｒ^１０は水素原子である上記［１］に記載の感光性樹脂組成物に関する。
（Ｄ）一般式（１）で表される化合物は、波長４００〜４４０ｎｍの光に対して大きな光吸収特性を有し、本発明に係る感光性樹脂組成物は、（Ｄ）一般式（１）で示される化合物を特定量含有しており、本発明は、［３］上記感光性樹脂組成物は、波長が４００〜４４０ｎｍの光に露光してレジストパターンを形成するために用いられる上記［１］又は上記［２］に記載の感光性樹脂組成物に関する。
従って、本発明の感光性樹脂組成物によれば、（Ｄ）一般式（１）で表される化合物を増感剤として用いていることにより、露光光として波長４００〜４４０ｎｍの光を用いた場合に、良好な光吸収特性を示すことができ、十分な感度、解像度、及び良好なレジスト形状を得ることができる。
また、本発明は、［４］支持フィルムと、該支持フィルム上に形成された上記［１］ないし上記［３］のいずれかに記載の感光性樹脂組成物からなる感光層と、を備えることを特徴とする感光性エレメントに関する。
本発明に係る感光性エレメントによれば、上記感光性樹脂組成物からなる感光層を備えることにより、波長４００〜４４０ｎｍの光に対して良好な光吸収特性を示すことができ、十分な感度、解像度、及び良好なレジスト形状を得ることができる。
更に、本発明の感光性エレメントに含まれている（Ｄ）一般式（１）で表される化合物は、波長３５０〜４００ｎｍの光に対しても大きな光吸収特性を有しているため、直接描画露光法のひとつである波長３５５ｎｍのＹＡＧ固体レーザーを光源としたＵＶ−ＬＤＩ（Ｌａｓｅｒ Ｄｉｒｅｃｔ Ｉｍａｇｉｎｇ）の露光光や、波長３６５ｎｍの光を中心とした水銀灯光源の全波長の光を用いた場合でも、十分な感度、解像度、及び良好なレジスト形状を得ることができる。

[In General Formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, A phenyl group, a benzyl group, an alkanoyl group having 2 to 12 carbon atoms or a benzoyl group is shown. R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a halogen atom, a cyano group, a carboxyl group, or a phenyl group. Represents an alkoxycarbonyl group having 2 to 6 carbon atoms or a benzoyl group. When the alkyl group has 2 to 12 carbon atoms, the alkyl group having 1 to 20 carbon atoms may have an oxygen atom between main chain carbon atoms, and may be substituted with a hydroxyl group. The cycloalkyl group having 5 to 12 carbon atoms may have an oxygen atom in the ring, and may be substituted with a hydroxyl group. The phenyl group in R ¹ and R ² is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and carbon. It may be substituted with one or more groups and / or atoms selected from the group consisting of alkoxycarbonyl groups of 2-6. The benzyl group is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and an alkoxycarbonyl group having 2 to 6 carbon atoms. It may be substituted with one or more groups and / or atoms selected from the group consisting of: The benzoyl group is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and an alkoxycarbonyl group having 2 to 6 carbon atoms. It may be substituted with one or more groups and / or atoms selected from the group consisting of: ]
Further, the present invention is a [2] The photosensitive resin composition (D) a compound represented by the general formula (1) is R ¹ or R ² are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms R ^{3 to} R ¹⁰ are related to the photosensitive resin composition according to the above [1], which is a hydrogen atom.
(D) The compound represented by the general formula (1) has a large light absorption characteristic with respect to light having a wavelength of 400 to 440 nm, and the photosensitive resin composition according to the present invention has (D) the general formula (1). In the present invention, [3] the photosensitive resin composition is used to form a resist pattern by exposing to light having a wavelength of 400 to 440 nm. 1] or the photosensitive resin composition according to [2] above.
Therefore, according to the photosensitive resin composition of the present invention, light having a wavelength of 400 to 440 nm was used as exposure light by using the compound represented by (D) general formula (1) as a sensitizer. In some cases, good light absorption characteristics can be exhibited, and sufficient sensitivity, resolution, and good resist shape can be obtained.
The present invention also includes [4] a support film, and a photosensitive layer made of the photosensitive resin composition according to any one of [1] to [3] above formed on the support film. The present invention relates to a photosensitive element.
According to the photosensitive element according to the present invention, by providing a photosensitive layer composed of the photosensitive resin composition, it is possible to exhibit good light absorption characteristics with respect to light having a wavelength of 400 to 440 nm, sufficient sensitivity, Resolution and good resist shape can be obtained.
Furthermore, since the compound represented by (D) the general formula (1) contained in the photosensitive element of the present invention has a large light absorption property even for light having a wavelength of 350 to 400 nm, Even when exposure light of UV-LDI (Laser Direct Imaging) using a YAG solid-state laser with a wavelength of 355 nm as a light source, which is one of the drawing exposure methods, or light of all wavelengths of a mercury lamp light source centered on light with a wavelength of 365 nm is used. Sufficient sensitivity, resolution, and good resist shape can be obtained.

The present invention also provides [5] a photosensitive layer forming step of forming a photosensitive layer comprising the photosensitive resin composition according to any one of [1] to [3] above on a substrate; The present invention relates to a resist pattern forming method including an exposure step of exposing a predetermined portion to light having a wavelength of 400 to 440 nm and a developing step of developing the exposed photosensitive layer to form a resist pattern.
The resist pattern forming method according to the present invention includes a photosensitive layer forming step of forming a photosensitive layer made of a photosensitive resin composition on a substrate, and exposing a predetermined portion of the photosensitive layer to light having a wavelength of 400 nm or more and less than 440 nm. An exposure step and a development step of developing the exposed photosensitive layer to form a resist pattern.
The present invention also provides [6] a photosensitive layer forming step of forming a photosensitive layer comprising the photosensitive resin composition according to any one of [1] to [3] above on a substrate; An exposure process for exposing a predetermined portion to light having a wavelength of 400 to 440 nm, a development process for developing the exposed photosensitive layer to form a resist pattern, and a conductor for forming a conductor pattern on the substrate based on the resist pattern And a pattern forming step.
The method for producing a printed wiring board according to the present invention includes a photosensitive layer forming step of forming a photosensitive layer made of a photosensitive resin composition on a substrate, and exposing a predetermined portion of the photosensitive layer to light having a wavelength of 400 nm or more and less than 440 nm. An exposure step for developing, a developing step for developing the exposed photosensitive layer to form a resist pattern, and a conductor pattern forming step for forming a conductor pattern on the substrate based on the resist pattern.

  According to the present invention, when forming a resist pattern with exposure light having a wavelength of 400 to 440 nm, a photosensitive resin composition capable of obtaining sufficient sensitivity, resolution, and good resist shape, and the same are used. A photosensitive element, a resist pattern forming method, and a printed wiring board manufacturing method are provided. This eliminates the need for exposure using ultraviolet rays that are harmful to the human body, and ensures work safety even if leaked.

Hereinafter, preferred embodiments according to the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto, (meth) acrylate means acrylate or corresponding methacrylate, and (meth) acryloyl group means acryloyl group or The corresponding methacryloyl group is meant.
The photosensitive resin composition of the present invention comprises (A) a binder polymer (hereinafter referred to as “component (A)”) and (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated bond (hereinafter referred to as “(B ) Component ”), (C) photo radical polymerization initiator (hereinafter referred to as“ (C) component ”), and (D) a compound represented by the above general formula (1) (hereinafter referred to as“ (D) component ”). And). Hereinafter, the components (A) to (D) will be described in detail.

(A) component of this invention should just be a polymer which can be photocured with the photopolymerizable compound mentioned later, and is not restrict | limited especially, For example, acrylic resin, styrene resin, epoxy resin, amide resin, Examples include organic polymers such as amide epoxy resins, alkyd resins, and phenol resins. Among them, monomers (polymerizable monomers) having ethylenically unsaturated double bonds are polymerized (radical polymerization, etc.). It is preferable that it is obtained.
Examples of the monomer having such an ethylenically unsaturated double bond include styrene, vinyltoluene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, and p-ethoxystyrene. , Polymerizable styrene derivatives such as p-chlorostyrene and p-bromostyrene, acrylamides such as diacetone acrylamide, esters of vinyl alcohol such as acrylonitrile and vinyl-n-butyl ether, alkyl (meth) acrylates, (meta ) Acrylic acid benzyl, (meth) acrylic acid benzyl derivative, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) ) (Meth) acrylic monomers such as acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, malein Examples include maleic acid monomers such as monoisopropyl acid, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid and the like. Among them, (meth) acrylic acid alkyl ester, styrene or styrene Derivatives, benzyl (meth) acrylate or benzyl (meth) acrylate are preferred. You may use these individually by 1 type or in combination of 2 or more types arbitrarily.
As said (meth) acrylic-acid alkylester, the compound etc. which the hydroxyl group, the epoxy group, the halogen atom, etc. substituted by the compound shown by following General formula (2) and the alkyl group of these compounds are mentioned, for example.

一般式（２）中、Ｒ^１１は、水素原子又はメチル基を示し、Ｒ^１２は炭素数１〜１２のアルキル基を示す。
なお、上記一般式（２）中のＲ^１２で示される炭素数１〜１２のアルキル基としては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基及びこれらの構造異性体等が挙げられる。
上記一般式（２）で示される化合物としては、例えば、（メタ）アクリル酸メチルエステル、（メタ）アクリル酸エチルエステル、（メタ）アクリル酸プロピルエステル、（メタ）アクリル酸ブチルエステル、（メタ）アクリル酸ペンチルエステル、（メタ）アクリル酸ヘキシルエステル、（メタ）アクリル酸ヘプチルエステル、（メタ）アクリル酸オクチルエステル、（メタ）アクリル酸２−エチルヘキシルエステル等が挙げられる。これらは１種を単独で又は２種以上を任意に組み合わせて用いることができる。

In General Formula (2), R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents an alkyl group having 1 to 12 carbon atoms.
As the alkyl group having 1 to 12 carbon atoms represented by R ¹² in the general formula (2), for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, heptyl group, octyl Group, nonyl group, decyl group, undecyl group, dodecyl group and structural isomers thereof.
Examples of the compound represented by the general formula (2) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (meth) Examples include 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, and the like. These can be used alone or in any combination of two or more.

The binder polymer as the component (A) is preferably composed of one or more kinds of polymers having a carboxyl group from the viewpoint of alkali developability. Such a (A) binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer.
The binder polymer as the component (A) has a structural unit based on (meth) acrylic acid as shown in the general formula (2) from the viewpoint of alkali developability and resolution. preferable.
The content of the structural unit based on (meth) acrylic acid is preferably 15 to 40% by weight based on the weight of the binder polymer, more preferably 17 to 37% by weight, and 20 to 35% by weight. It is particularly preferred. If the content of the structural unit based on (meth) acrylic acid is less than 15% by weight, the alkali solubility is inferior, the peel piece tends to be large, and the peel time tends to be long. When this content exceeds 40% by weight, There is a tendency for image quality to decrease.
In addition, from the viewpoint of improving both adhesion and peeling properties, the (A) binder polymer preferably contains styrene or a styrene derivative as a polymerizable monomer. In the present invention, the “styrene derivative” refers to a compound in which a hydrogen atom in styrene is substituted with a substituent (an organic group of an alkyl group, a halogen atom, or the like).
When the styrene or styrene derivative is contained as a copolymerization component, the content of styrene or styrene derivative in the component (A) is preferably 10 to 65% by weight based on the weight of the binder polymer. It is more preferably 50% by weight, and particularly preferably 25 to 45% by weight. If the content is less than 10% by weight, the adhesion tends to be inferior. If the content exceeds 65% by weight, the peeled piece tends to be large and the peeling time tends to be long.
Moreover, from the viewpoint of resolution and peelability, the (A) binder polymer more preferably has a structural unit based on benzyl (meth) acrylate or a benzyl (meth) acrylate derivative.
The content of structural units based on benzyl (meth) acrylate or benzyl (meth) acrylate is preferably 5 to 60% by weight, and preferably 7 to 50% by weight based on the weight of the binder polymer. More preferred. If the content of the structural unit based on benzyl (meth) acrylate or a benzyl derivative (meth) acrylate is less than 5% by weight, the resolution tends to be inferior. It tends to be large and the peeling time is long.
The binder polymer as the component (A) is used singly or in combination of two or more. 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, two or more types of binder polymers having different weight average molecular weights, and two or more types of binder polymers having different degrees of dispersion are used. A binder polymer etc. are mentioned. 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 number average molecular weight (Mn) of the binder polymer as the component (A) 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 5000 to 300000, more preferably 20000 to 150,000, and particularly preferably 30000 to 80000. 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 binder polymer as the component (A) 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.

Next, the photopolymerizable compound having a polymerizable ethylenically unsaturated bond (hereinafter referred to as “photopolymerizable compound”) as component (B) will be described. (B) component of this invention should just be a photopolymerizable compound which has the ethylenically unsaturated bond which can superpose | polymerize in a molecule | numerator, Although it does not restrict | limit, For example, the following photopolymerizable compounds are mentioned, for example.
That is, as the component (B) of the present invention, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol, a bisphenol A (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, nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, (meth) acrylic acid alkyl esters, etc. It is done. These are used individually by 1 type or in combination of 2 or more types.
Further, from the viewpoint of more reliably obtaining the effects of the present invention, a photopolymerizable compound having one polymerizable ethylenically unsaturated bond in the molecule and two or more polymerizable ethylenically unsaturated bonds in the molecule. It is preferable to use in combination with a photopolymerizable compound having
In addition, the photopolymerizable compound as the component (B) is a bisphenol A (meth) acrylate compound or a (meth) acrylate compound having a urethane bond in the molecule from the viewpoint of plating resistance, adhesion, and resolution. It is preferable to contain as an essential component.

In the present invention, the bisphenol A-based (meth) acrylate compound is a carbon-carbon unsaturated double bond derived from a (meth) acryloyl group or a (meth) acryloyl group, and -C ₆ H ₄ -C derived from bisphenol A. A compound having (CH ₃ ) ₂ -C ₆ H ₄ -group.
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, tetramethylolmethanetri (meta) ) Acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like. These are used individually by 1 type or in combination of 2 or more types.
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) acryloxypoly). Propoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, etc. Is mentioned. 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) acryloxynonane) Xyl) 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.
Among them, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is FA-321M (manufactured by Hitachi Chemical Co., Ltd., product name) or BPE-500 (manufactured by Shin-Nakamura 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). Is possible. The number of ethylene oxide groups (EO groups) in one molecule of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably 4-20, and 8-15. It is more preferable. These are 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 EO and PO-modified urethane di (meth) acrylate include UA-13 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name).
These are used individually by 1 type or in combination of 2 or more types.

  Examples of the nonylphenoxypolyethyleneoxyacrylate include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethylene Examples include oxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate. These are used individually by 1 type or in combination of 2 or more types.

  Examples of the phthalic acid compounds include γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate. Etc. Among them, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate is commercially available as FA-MECH (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name). These are used individually by 1 type or in combination of 2 or more types.

The component (B) preferably includes a bisphenol A (meth) acrylate compound or a (meth) acrylate compound having a urethane bond in the molecule from the viewpoint of plating resistance and adhesion. Moreover, it is preferable that a bisphenol A type (meth) acrylate compound is included from a viewpoint which can improve a sensitivity and a resolution.
Furthermore, the component (B) preferably contains polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule from the viewpoint of improving the flexibility of the cured film. This (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 alkylene glycol chains in the molecule. In addition, this (meth) acrylate further includes an n-butylene glycol chain, an isobutylene glycol chain, an n-pentylene glycol chain, a hexylene glycol chain, an alkylene glycol chain having about 4 to 6 carbon atoms such as a structural isomer thereof. You may have.
When there are a plurality of ethylene glycol chains and propylene glycol chains, the plurality of ethylene glycol chains and propylene glycol chains do not need to be continuously present in blocks, but 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.

  Examples of the polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule in the component (B) include, for example, a compound represented by the following general formula (3), Examples thereof include a compound represented by (4) and a compound represented by the following general formula (5).

Here, in said general formula (3), general formula (4), and general formula (5), R < ¹³ > -R < ¹⁸ > shows a hydrogen atom or a C1-C3 alkyl group each independently, EO is ethylene. A glycol chain is shown, PO is a propylene glycol chain, and m ^{1 to} m ⁴ and n ^{1 to} n ⁴ are each independently an integer of 1 to 30. These compounds can be used individually by 1 type or in combination of 2 or more types.
In R ^{13 to} R ¹⁸ in the general formulas (3) to (5), examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group.
The total number (m ¹ + m ² , m ³ and m ⁴ ) of ethylene glycol chain repeats in the general formulas (3) to (5) is an integer of 1 to 30, and an integer of 1 to 10. Is preferable, an integer of 4 to 9 is more preferable, and an integer of 5 to 8 is particularly preferable. If the number of repetitions exceeds 30, the tent reliability and the resist shape tend to deteriorate.
The total number of propylene glycol chain repeats (n ¹ , n ² + n ³ and n ⁴ ) in the general formulas (3) to (5) is an integer of 1 to 30, and an integer of 5 to 20. Is preferable, an integer of 8 to 16 is more preferable, and an integer of 10 to 14 is particularly preferable. If the number of repetitions exceeds 30, the resolution deteriorates and sludge tends to be generated.
Specific examples of the compound represented by the general formula (3) include, for example, vinyl having R ¹³ = R ¹⁴ = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value). Compound (manufactured by Hitachi Chemical Co., Ltd., product name “FA-023M”) and the like. Specific examples of the compound represented by the general formula (4) include, for example, R ¹⁵ = R ¹⁶ = methyl group, m ³ = 6 (average value), n ² + n ³ = 12 (average value) A certain vinyl compound (manufactured by Hitachi Chemical Co., Ltd., product name “FA-024M”) is exemplified. Furthermore, specific examples of the compound represented by the general formula (5) include, for example, vinyl in which R ¹⁷ = R ¹⁸ = hydrogen atom, m ⁴ = 1 (average value), and n ⁴ = 9 (average value). Examples thereof include compounds (manufactured by Shin-Nakamura Chemical Co., Ltd., sample name “NK ester HEMA-9P”) and the like. These compounds can be used individually by 1 type or in combination of 2 or more types.
The content of the component (B) in the photosensitive resin composition is preferably 30 to 70% by weight, and 40 to 60% by weight, based on the total solid content of the component (A) and the component (B). It is more preferable. If this content is less than 30% by weight, good sensitivity and resolution tend to be difficult to obtain, and if it exceeds 70% by weight, a good resist shape tends to be difficult to obtain.

Next, the radical photopolymerization initiator as component (C) will be described.
Examples of the component (C) of the present invention include 4,4′-bis (diethylamine) benzophenone, benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl. Aromatic ketones such as -1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinone, benzoin compounds such as benzoin and alkylbenzoin, benzoin ether compounds such as benzoin alkyl ether, Benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (O-Fluorophenyl) -4,5-diphenylimidazole 2,4,5- such as dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Triarylimidazole dimer, 9-phenylacridine, acridine derivatives such as 1,7-bis (9,9′-acridinyl) heptane, N-phenylglycine, N-phenylglycine derivatives, 7-diethylamino-4-methylcoumarin And the like.
The two aryl substituents of the 2,4,5-triarylimidazole dimer may give the same and symmetric compounds or differently give asymmetric compounds. From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is preferable, and 2,4,5-triarylimidazole dimer represented by the following general formula (6) is more preferable. preferable. These are used individually by 1 type or in combination of 2 or more types.

Here, in the general formula (6), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently have at least one substituent selected from the group consisting of an alkyl group, an alkenyl group and an alkoxy group. An aryl group which may be, X ¹ and X ² each independently represent a chlorine atom, an alkyl group, an alkenyl group or an alkoxy group, and a and b each independently represent an integer of 1 to 5. However, at least one of X ₁ and X ₂ represents a chlorine atom.
By containing the 2,4,5-triarylimidazole dimer represented by the general formula (6), the photosensitive resin composition is sufficiently and uniformly cured with exposure light having a wavelength of 400 to 440 nm. More sufficient sensitivity and resolution can be obtained, and a better resist shape can be obtained.
The content of the component (C) in the photosensitive resin composition is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the total solid content of the component (A) and the component (B). The amount is more preferably 6 parts by weight, and particularly preferably 3.5 to 5 parts by weight. If this content is less than 0.1 parts by weight, good sensitivity and resolution tend to be difficult to obtain, and if it exceeds 10 parts by weight, a good resist shape tends to be difficult to obtain.

  Next, the compound represented by the following general formula (1) which is the component (D) will be described.

The photosensitive resin composition of the present invention is useful for forming a resist pattern by exposing to light having a wavelength of 400 nm or more and less than 440 nm by containing the component (D).
Examples of R ¹ and R ² in the component (D) include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of R ^{3 to} R ¹⁰ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an ethoxycarbonyl group. , Hydroxyethoxycarbonyl group, or phenoxy group. As combinations of R ^{3 to} R ¹⁰ , all of them are hydrogen atoms, and any one of them is methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, propenyl group, butenyl group, pentenyl group, A xenyl group, a heptenyl group, an ethoxycarbonyl group, a hydroxyethoxycarbonyl group, or a phenoxy group, all of which are hydrogen atoms, and any two of them are a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group A hexyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an ethoxycarbonyl group, a hydroxyethoxycarbonyl group, or a phenoxy group, or a combination thereof, and everything else is a hydrogen atom , Etc.
Specific examples of the compound represented by the general formula (1) as component (D) include 9-aminoacridine, 9-monomethylaminoacridine, 9-dimethylaminoacridine, 9-monoethylaminoacridine, and 9-diethylamino. Acridine, 9-monopropylaminoacridine, 9-dipropylaminoacridine, 9-monobutylaminoacridine, 9-dibutylaminoacridine, 9-monopentylaminoacridine, 9-dipentylaminoacridine, 9-monohexylaminoacridine, 9 -Dihexylaminoacridine, 9-methylethylaminoacridine, 9-methylpropylaminoacridine, 9-methylbutylaminoacridine, 9-ethylpropylaminoacridine, 9-ethylbutylaminoacridine, 9-ethylpentyl Minoakurijin, 9-ethylhexyl amino acridine, and the like.
Furthermore, as component (D), from the viewpoint of sensitivity, resolution, and adhesion, 9-monoalkylamino, wherein either R ¹ or R ² represented by the general formula (1) is a hydrogen atom, It preferably contains acridine, more preferably 9-monopentylaminoacridine. 9-monopentylaminoacridine is commercially available as ACR-2 (Nippon Distillation Co., Ltd., sample name).
Moreover, it is preferable that the compounding quantity of (D) component of this invention shall be 0.01-10 weight part with respect to 100 weight part of total amounts of (A) component and (B) component, and 0.05-5 weight More preferably, the content is 0.1 to 2 parts by weight. If the 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 pattern shape tends to be not obtained.

  In the photosensitive resin composition of this invention, you may contain components other than the above-mentioned (A)-(D) component as needed. Such components include photopolymerizable compounds having at least one cationically polymerizable cyclic ether group in the molecule (such as oxetane compounds), cationic polymerization initiators, dyes such as malachite green, tribromophenylsulfone, leucocrystals. Photo-coloring agents such as violet, thermo-coloring prevention agents, plasticizers such as p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, oxidation Examples thereof include an inhibitor, a fragrance, an imaging agent, and a thermal crosslinking agent. These should just be added to such an extent that the achievement of the object of the present invention is not hindered. The amount of these components added can be about 0.01 to 20 parts by weight per 100 parts by weight of the total amount of the component (A) and the 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 to 60 weight% of solid content. This solution can be used as a coating solution for forming the photosensitive layer of the photosensitive element.
Further, the above coating solution may be used to form a photosensitive layer of a photosensitive element by applying and drying on a support film described later. For example, the surface of a metal plate, for example, copper, copper-based An alloy, nickel, chromium, iron, stainless steel, or other iron-based alloy, preferably copper, copper-based alloy, or iron-based alloy may be coated as a liquid resist, dried, and then coated with a protective film. .

Next, the photosensitive element of the present invention will be described. 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 includes a support film 10 and a photosensitive layer 14 made of a photosensitive resin composition formed on the support film 10. You may further provide the protective film (not shown) which coat | covers.
As the support film 10, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. The thickness of the support film 10 (polymer film) is preferably 1 to 100 μm. If the thickness is less than 5 μm, the support film 10 tends to be broken when the support film 10 is peeled off before development, and if it exceeds 25 μm, the resolution tends to decrease. In addition, you may use the support film 10 by laminating | stacking on the both surfaces of the photosensitive layer 14 one as a support body of the photosensitive layer 14, and the other as a protective film of the photosensitive resin composition.
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 polypropylene film such as product names “Alphan MA-410” and “E-200C” manufactured by Oji Paper Co., Ltd., Shin-Etsu Film Co., Ltd., and product name “PS-” manufactured by Teijin Limited. Polyethylene terephthalate film such as PS series such as “25” can be mentioned, but is not limited thereto. The thickness of the protective film is preferably 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 this 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 protective film preferably has a smaller adhesive strength between the photosensitive layer 14 and the protective film than the adhesive strength between the photosensitive layer 14 and the support film 10, and is preferably a low fisheye film. Fisheye is a material in which foreign materials, undissolved materials, oxidatively deteriorated materials, etc. are incorporated into the film when the material is melted and kneaded, extruded, biaxially stretched, or casted to produce a film. It is.
The photosensitive layer 14 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 weight. It is preferable to form by coating on the support film 10 and drying. The application can be performed by a known method using, for example, a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater or the like. Moreover, the said 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 weight or less with respect to the total amount of the photosensitive resin composition from the viewpoint of preventing diffusion of the organic solvent in the subsequent step. Although the thickness of the photosensitive layer 14 varies depending on the application, it is preferably 1 to 100 μm, more preferably 1 to 50 μm in terms of the thickness after drying. 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 be reduced.
The photosensitive layer 14 preferably has an absorbance with respect to an ultraviolet ray having a wavelength of 405 nm of 0.1 to 3, more preferably 0.15 to 2, and particularly preferably 0.2 to 1.5. preferable. If the absorbance is less than 0.1, the sensitivity tends to be inferior, and if it exceeds 3, the adhesion tends to be inferior. The absorbance can be measured by a UV spectrometer, and examples of the UV spectrometer include a 228A type (manufactured by Hitachi, Ltd., product name) W beam spectrophotometer.

  The photosensitive element 1 may further include 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 sheet form or a roll around a core. In addition, it is preferable to wind up so that a support body (support film) may become the outermost part in this case. An end face separator is preferably installed on the end face of the roll-shaped photosensitive element 1 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. Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

Next, the resist pattern forming method of the present invention using the photosensitive element 1 of the present invention will be described. The resist pattern forming method of the present invention includes a photosensitive layer forming step of forming a photosensitive layer 14 made of a photosensitive resin composition on a circuit forming substrate, and a predetermined portion of the photosensitive layer 14 is irradiated with light having a wavelength of 400 nm or more and less than 440 nm. It comprises an exposure step of exposing and a developing step of developing the exposed photosensitive layer 14 to form a resist pattern. The circuit forming substrate refers to a substrate provided with an insulating layer and a conductor layer formed on the insulating layer.
In the photosensitive layer forming step, the protective film of the photosensitive element 1 described above is gradually peeled off from the photosensitive layer 14, and at the same time, the portion of the surface of the photosensitive layer 14 that is gradually exposed is used as the circuit of the circuit forming substrate. Is closely attached to the surface to be formed. When forming the resist pattern, after removing the protective film, for example, while heating the photosensitive layer 14 to about 70 to 130 ° C., about 0.1 to 1 MPa (1 to 10 kgf / cm ^{2) on the} circuit forming substrate. A method of laminating by pressure bonding at a pressure of about a degree is suitably employed, and a method of laminating under reduced pressure is also preferable from the viewpoint of improving adhesion and followability (lamination step). In addition, if the photosensitive layer 14 is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate. However, in order to further improve the stackability, the pre-heat treatment of the circuit forming substrate is performed. Can also be done.

Next, in the exposure step, an active ray is irradiated 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. Moreover, you may employ | adopt the method of irradiating actinic light in an image form through the negative or positive mask pattern called an artwork (mask exposure method). In the case of the exposure step, when the support film 10 present on the photosensitive layer 14 is transparent to actinic rays, it can be irradiated with actinic rays through the support film 10, and the support film 10 is light-shielding. In some cases, the photosensitive layer 14 can be irradiated with actinic rays after the support film 10 is removed.
As the actinic light source, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, a high pressure mercury lamp, a xenon lamp, an Ar ion laser, a semiconductor laser, or the like that effectively emits ultraviolet light or visible light is used. It is done. In the present invention, it is desirable to use an actinic ray obtained by cutting 99.5% or more of light having a wavelength of 405 nm of a semiconductor laser or light having a wavelength of 365 nm or less of a mercury lamp light source using a filter. As a filter for cutting light having a wavelength of 365 nm or less, for example, a sharp cut filter SCF-100S-39L (manufactured by Sigma Koki Co., Ltd., product name) or the like can be used.
Furthermore, in the said image development process, when the support body (support film) exists on the photosensitive resin composition layer, after removing the support body, the part which is not photocured by wet development or dry development ( By removing the unexposed portion and developing, a resist pattern can be formed.
In the case of the above-described wet development, as the developer, an alkaline aqueous solution, an aqueous developer, an organic solvent, or the like that is safe and stable and has good operability is used according to the type of the photosensitive resin composition. Further, as a developing method, a known method such as spraying, rocking dipping, brushing, scraping or the like is appropriately employed.

Examples of the base of the alkaline aqueous solution include alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide which are hydroxides of lithium, sodium and potassium, carbonates or bicarbonates such as alkali metals and ammonium. Alkaline carbonate or bicarbonate, alkali metal phosphate sodium phosphate, potassium phosphate, etc., alkali metal pyrophosphate sodium pyrophosphate, potassium pyrophosphate etc., safe and stable, operability The one with good is used.
Examples of such an alkaline aqueous solution include a dilute solution of 0.1 to 5 wt% sodium carbonate, a dilute solution of 0.1 to 5 wt% potassium carbonate, and a dilute solution of 0.1 to 5 wt% sodium hydroxide. A solution, a dilute solution of 0.1 to 5 wt% sodium tetraborate is preferred, and its pH is preferably in the range of 9-11. Further, the temperature of the alkaline aqueous solution is adjusted in accordance with the developability of the photosensitive layer 14. Furthermore, a small amount of an organic solvent such as a surfactant or an antifoaming agent may be mixed in the alkaline aqueous solution in order to promote development.

  As the aqueous developer, one comprising water and an alkaline aqueous solution or one or more organic solvents is used. Here, as the base of the alkaline aqueous solution, in addition to those described above, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3- Examples include propanediol, 1,3-diaminopropanol-2, and morpholine. The pH of such an aqueous developer is preferably as small as possible within a range where development processing can be sufficiently performed, preferably pH 8 to 12, and more preferably pH 9 to 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, and diethylene glycol monobutyl ether. . The concentration of such an organic solvent is usually preferably 2 to 90% by weight. Moreover, the temperature of such an organic solvent can be adjusted according to developability. Such organic solvents can be used alone or in combination of two or more. 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. Furthermore, a small amount of an organic solvent such as a surfactant or an antifoaming agent may be mixed in the alkaline aqueous solution in order to promote development. The organic solvent is preferably added in an amount of 1 to 20% by weight in order to prevent ignition.

In the method for forming a resist pattern of the present invention, if necessary, two or more kinds of development methods described above may be used in combination. Development methods include a dip method, a battle method, a spray method, a high-pressure spray method, brushing, and slapping, and the high-pressure spray method is most suitable for improving resolution. Moreover, as a process after image development, the resist pattern may be further cured by heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 mJ / 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.

Next, the manufacturing method of the printed wiring board of this invention is demonstrated. The method for producing a printed wiring board of the present invention comprises a photosensitive layer forming step of forming a photosensitive layer 14 made of a photosensitive resin composition on a circuit forming substrate, and a predetermined portion of the photosensitive layer 14 having a wavelength of 400 nm or more and less than 440 nm. An exposure step of exposing to light; a development step of developing the exposed photosensitive layer 14 to form a resist pattern; and a conductor pattern forming step of forming a conductor pattern on a circuit forming substrate based on the resist pattern. That is. The circuit forming substrate refers to a substrate provided with an insulating layer and a conductor layer formed on the insulating layer.
That is, in the method for manufacturing a printed wiring board of the present invention, the surface of the circuit forming substrate is subjected to etching or plating using the resist pattern obtained by the resist pattern forming method of the present invention as a mask.

In order to perform the etching process on the surface of the circuit forming substrate, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, and a hydrogen peroxide etching solution can be used. A ferric chloride solution is preferred because of its good etch factor.
Examples of the plating treatment include copper plating treatment such as copper sulfate plating treatment, copper pyrophosphate plating treatment, solder plating treatment such as high throw plating treatment, watt bath (nickel sulfate-nickel chloride) plating treatment, nickel sulfamate treatment. A known method for performing gold plating such as nickel plating, hard gold plating, or soft gold plating can be appropriately employed.

Next, in the method for producing a printed wiring board of the present invention, for example, the resist pattern may be peeled and removed using a stronger alkaline aqueous solution than the alkaline aqueous solution used for development. As such a strong alkaline aqueous solution, for example, a 1 to 10% by weight sodium hydroxide aqueous solution and a 1 to 10% by weight potassium hydroxide aqueous solution are used. In addition, examples of a method for peeling and removing the resist pattern include an immersion method and a spray method. The immersion method and the spray method may be used alone or in combination.
The method for producing a printed wiring board according to the present invention is applicable not only to the production of a single-layer printed wiring board but also to the production of a multilayer printed wiring board, for producing a printed wiring board having a small-diameter through hole. Is also applicable.
The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples.
(Examples 1-3 and Comparative Examples 1-2)
(Preparation of photosensitive resin composition)
First, the components shown in Table 1 below were mixed in the amounts (g) shown in the same table to obtain a solution.

＊１：２，２−ビス（４−（メタクリロキシペンタエトキシ）フェニル）プロパン（日立化成工業株式会社製、製品名「ＦＡ−３２１Ｍ」）
＊２：上記一般式（３）で表される化合物で、Ｒ^１３＝Ｒ^１４＝メチル基、ｍ^１＋ｍ^２＝４（平均値）、ｎ^１＝１２（平均値）であるビニル化合物（日立化成工業株式会社製、製品名「ＦＡ−０２３Ｍ」）
＊３：γ−クロロ−β−ヒドロキシプロピル−β'−（メタ）アクリロイルオキシエチル−ｏ−フタレート（大阪有機化学工業株式会社製、製品名「ＦＡ−ＭＥＣＨ」）

* 1: 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (manufactured by Hitachi Chemical Co., Ltd., product name “FA-321M”)
* 2: A compound represented by the above general formula (3), wherein R ¹³ = R ¹⁴ = methyl group, m ¹ + m ² = 4 (average value), and n ¹ = 12 (average value) (Hitachi) (Product name “FA-023M” manufactured by Kasei Kogyo Co., Ltd.)
* 3: γ-Chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate (product name “FA-MECH” manufactured by Osaka Organic Chemical Industry Co., Ltd.)

  Subsequently, the sensitizer which is (D) component was dissolved with the quantity (g) shown in Table 2 in the obtained solution, and the solution of the photosensitive resin composition was obtained.

＊^４：９−モノペンチルアミノアクリジン（日本蒸留工業株式会社、サンプル名「ＡＣＲ−２」；λ_ｍａｘ＝４０１ｎｍ）
＊^５：４，４′−ビス（ジエチルアミノ）ベンゾフェノン（保土ヶ谷化学工業株式会社製、製品名「ＥＡＢ」；λ_ｍａｘ＝３６５ｎｍ）

* ⁴ : 9-monopentylaminoacridine (Nippon Distillation Co., Ltd., sample name “ACR-2”; λ _max = 401 nm)
* ⁵ : 4,4′-bis (diethylamino) benzophenone (manufactured by Hodogaya Chemical Co., Ltd., product name “EAB”; λ _max = 365 nm)

(Production of photosensitive element)
The obtained photosensitive resin composition solution was uniformly applied onto a 16 μm-thick polyethylene terephthalate film (product name “GS-16”, manufactured by Teijin Limited), which is a support (support film). A photosensitive resin composition layer (photosensitive layer) is formed by drying with a 100 ° C. hot air convection dryer (feed rate: 3 m / min, drying furnace length: 3 m each), and a polyethylene film is used as a protective film A photosensitive element was obtained. The film thickness after drying of the photosensitive layer was 25 μm.

<Absorbance test>
The absorbance of the photosensitive layer 14 with respect to the exposure wavelength was measured using a UV spectrophotometer (manufactured by Hitachi, Ltd., product name “U-3310 spectrophotometer”). The measurement is based on the same type of polyethylene terephthalate film used as the support, and the UV absorption spectrum is obtained by continuous measurement with light having a wavelength of 300 to 550 nm in the absorbance mode. Among them, the absorbance value at 405 nm is obtained. I read. The measurement results are shown in Table 3.

(Formation of resist pattern)
About each obtained photosensitive element, the photosensitive layer was laminated on the copper clad laminated board with the following method, and the laminated body was obtained. That is, the copper surface of a copper clad laminate (product name “MCL-E-67”, manufactured by Hitachi Chemical Co., Ltd.), which is a glass epoxy agent in which copper foil (thickness 35 mm) is laminated 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 dried with an air flow. The obtained copper-clad laminate was heated to 80 ° C., and the photosensitive resin composition was removed at 120 ° C. under a pressure of 0.4 MPa while peeling the protective film of the photosensitive element on the copper-clad laminate. A laminate was obtained by laminating.

<Light sensitivity and resolution test>
Subsequently, the laminate is cooled to 23 ° C., and on the surface of the polyethylene terephthalate film located in the outermost layer of the laminate, a concentration region of 0.00 to 2.00, a concentration step of 0.05, a tablet ( A photo tool having a 41-step tablet with a (rectangular) size of 20 mm × 187 mm and each step (rectangular) size of 3 mm × 12 mm was brought into close contact.
In this state, a direct drawing exposure machine (product name “DE-1AH” manufactured by Hitachi Via Mechanics Co., Ltd.) using a 405 nm blue-violet laser diode as a light source is used for drawing at a predetermined exposure amount, and a 41-step tablet The number of remaining steps after development was determined. Exposure was performed at an exposure amount at which the number of remaining step steps after development of the 41-step tablet was 14 steps, and this exposure amount was defined as sensitivity. In the evaluation of sensitivity, the smaller the value, the better the value. The results are shown in Table 3.

In addition, a direct drawing exposure machine (product name “DE-1AH” manufactured by Hitachi Via Mechanics Co., Ltd.) using a 405 nm blue-violet laser diode as a light source is used from above the polyethylene terephthalate film located in the outermost layer of the laminate. A drawing pattern having a remaining pattern (resolution (remaining)) and a removal pattern (resolution (removal)) having a line width / space width of 5/5 to 30/30 (unit: μm) is 120 mJ / cm ² and 130 mJ. / Cm ² and 140 mJ / cm ² were respectively exposed.
Here, FIG. 2 is a top view schematically showing the direct drawing data for resolution evaluation. As for the remaining pattern, the line portion 22 is exposed in the direct drawing data 20 shown in FIG. On the other hand, as for the blank pattern, the line portion 24 is exposed in the direct drawing data 20 shown in FIG.
Next, the polyethylene terephthalate film was peeled off and sprayed with a 1% by weight aqueous sodium carbonate solution at 30 ° C. for 27 seconds to remove unexposed portions. The resolution (remaining) was evaluated based on the smallest value of the line width in which the unexposed portion could be removed cleanly by the development process, and the lines were generated without snakes and burrs. Further, the resolution (extraction) was evaluated based on the smallest value of the space width in which the unexposed portion could be removed cleanly by the development process. The smaller the numerical value, the better the resolution evaluation. The results are shown in Table 3. A value of> 30 (unit: μm) in Table 3 indicates that even with a pattern having the largest line width / space width, adhesion was not obtained, and the resist in the exposed portion was completely removed by development processing.
The resist shape after development was observed using a Hitachi scanning electron microscope S-500A. The results are shown in Table 3.

  Comparative Example 2 using no sensitizer is inferior in absorbance, sensitivity, and resolution, and Comparative Example 1 using a benzophenone system as the sensitizer has an absorbance of about 0.3 at 405 nm. At a lower sensitivity value, the resolution is 16-20 μm. On the other hand, Examples 1-3 using the compound represented by the general formula (1) of the present invention as a sensitizer have high absorbance and excellent sensitivity. Moreover, the resolution is 9 to 12 μm, the resolution is excellent, and a resist pattern having an excellent resolution can be formed by exposure at a wavelength of 400 to 440 nm.

It is a schematic cross section which shows one Embodiment of the photosensitive element by this invention. It is a top view which shows the direct drawing data for resolution evaluation typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive element 10 Support film 14 Photosensitive layer 20 Direct drawing data 22 Line part 24 Space part

Claims (6)

(A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated bond, (C) a radical photopolymerization initiator, and (D) a compound represented by the following general formula (1) And a photosensitive resin composition.

[In General Formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, A phenyl group, a benzyl group, an alkanoyl group having 2 to 12 carbon atoms or a benzoyl group is shown. R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a halogen atom, a cyano group, a carboxyl group, or a phenyl group. Represents an alkoxycarbonyl group having 2 to 6 carbon atoms or a benzoyl group. When the alkyl group has 2 to 12 carbon atoms, the alkyl group having 1 to 20 carbon atoms may have an oxygen atom between main chain carbon atoms, and may be substituted with a hydroxyl group. The cycloalkyl group having 5 to 12 carbon atoms may have an oxygen atom in the ring, and may be substituted with a hydroxyl group. The phenyl group in R ¹ and R ² is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and carbon. It may be substituted with one or more groups and / or atoms selected from the group consisting of alkoxycarbonyl groups of 2-6. The benzyl group is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and an alkoxycarbonyl group having 2 to 6 carbon atoms. It may be substituted with one or more groups and / or atoms selected from the group consisting of: The benzoyl group is an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, and an alkoxycarbonyl group having 2 to 6 carbon atoms. It may be substituted with one or more groups and / or atoms selected from the group consisting of: ] Said R < ¹ > or R < ² > of the compound represented by (D) general formula (1) of the said photosensitive resin composition shows a hydrogen atom or a C1-C6 alkyl group, respectively, R < ³ >, R < ⁴ >, The photosensitive resin composition according to claim 1, wherein R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are hydrogen atoms. The said photosensitive resin composition is a photosensitive resin composition of Claim 1 or Claim 2 used in order to form a resist pattern by exposing to the light whose wavelength is 400-440 nm. A photosensitive element comprising: a support film; and a photosensitive layer made of the photosensitive resin composition according to claim 1 formed on the support film. A photosensitive layer forming step of forming a photosensitive layer comprising the photosensitive resin composition according to any one of claims 1 to 3 on a substrate, and exposing a predetermined portion of the photosensitive layer to light having a wavelength of 400 to 440 nm. A resist pattern forming method comprising: an exposing step of developing; and a developing step of developing the exposed photosensitive layer to form a resist pattern. A photosensitive layer forming step of forming a photosensitive layer comprising the photosensitive resin composition according to any one of claims 1 to 3 on a substrate, and exposing a predetermined portion of the photosensitive layer to light having a wavelength of 400 to 440 nm. A printed wiring board comprising: an exposing step for developing; a developing step for developing the exposed photosensitive layer to form a resist pattern; and a conductor pattern forming step for forming a conductor pattern on the substrate based on the resist pattern. Production method.

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