JP2010169810A - Photosensitive resin composition and photosensitive element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition having excellent alkali developability, excellent in film thickness accuracy when a solution thereof is applied, and capable of forming a cured film excellent in folding resistance and flame retardancy, and to provide a photosensitive element. <P>SOLUTION: The photosensitive resin composition contains: (A) a binder polymer; (B) an organic filler of 1-3 μm maximum particle size, comprising a phosphorus-containing compound; (C) a photopolymerizable compound; and (D) a photopolymerization initiator. Preferably, the photosensitive resin composition further contains (E) a heat curing agent and (F) a dispersant. The photosensitive element includes a support and a photosensitive resin composition layer comprising the photosensitive resin composition formed on the support. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition and a photosensitive element using the same.

In the printed wiring board manufacturing industry, conventionally, a solder resist is formed on a printed wiring board. This solder resist has a role to prevent solder from adhering to unnecessary portions of the conductor layer of the printed wiring board in the soldering process for bonding the mounted part to the printed wiring board. When the printed wiring board is used later, it also serves as a permanent mask for preventing corrosion of the conductor layer and maintaining electrical insulation between the conductor layers.
As a method for forming a solder resist, for example, a method of screen printing a thermosetting resin on a conductor layer of a printed wiring board is known. However, since such a method has a limit in increasing the resolution of the resist pattern, it has become difficult to cope with the recent increase in the density of printed wiring boards.
Therefore, in order to achieve high resolution of the resist pattern, the photoresist method has been actively used. In this photoresist method, a photosensitive resin composition layer made of a photosensitive resin composition is formed on a substrate, the photosensitive resin composition layer is cured by exposure of a predetermined pattern, and unexposed portions are removed by development. Thus, a cured film having a predetermined pattern is formed.
In addition, the photosensitive resin composition used in such a method is mainly an alkali development type that can be developed with a dilute aqueous alkali solution such as an aqueous sodium carbonate solution from the viewpoint of conservation of the working environment and global environment. .
As such a photosensitive resin composition, for example, a liquid resist ink composition described in Patent Document 1 below and a photosensitive thermosetting resin composition described in Patent Document 2 below are known.

JP-A 61-243869 Japanese Patent Laid-Open No. 01-141904

By the way, in recent years, regulations on flame retardancy of various industrial products against fire have become stricter, and materials used for printed wiring boards and the like are no exception. As a flame retardant method, a method of adding a halogen compound, an antimony compound, a phosphorus compound, a boron compound, an inorganic filler or the like to a material is generally known.
However, recently, with increasing interest in environmental issues and human safety issues, the focus has shifted to non-polluting, low toxic and safety, not only flammable but also harmful gases and fuming substances. Reduction is being demanded. In response, flame retardant substrates that do not use halogen compounds or antimony compounds have already been developed and put into practical use.
However, when a cured film is formed on a flame retardant substrate as described above using a conventional photosensitive resin composition as described in Patent Documents 1 and 2, sufficient flame retardancy (preferably, (UL94 VTM-0 level) cannot be ensured by examination by the present inventors.
Then, although the method of improving the flame retardance of a cured film using a phosphorus organic filler is examined, when a photosensitive element is formed using the photosensitive resin composition containing the said organic filler, a support body is formed. When coating the solution of the photosensitive resin composition on top, there has been a problem that the film thickness accuracy is lowered or the bending resistance of the cured film is lowered.
The present invention has been made in view of the above circumstances, has excellent alkali developability, is excellent in film thickness accuracy when applying a solution of a photosensitive resin composition, and has folding resistance and flame retardancy. It aims at providing the photosensitive resin composition which can form the cured film excellent in property. Moreover, an object of this invention is to provide the photosensitive element provided with the photosensitive resin composition layer which consists of such a photosensitive resin composition.

As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by including a resin having a specific structure and a phosphorus-containing compound in a photosensitive resin composition. The present invention has been completed.
That is, the present invention relates to [1] (A) a binder polymer, (B) an organic filler having a maximum particle size of 1 to 3 μm comprising a phosphorus-containing compound, (C) a photopolymerizable compound, and (D) photopolymerization. A photosensitive resin composition containing an initiator is provided.
According to such a photosensitive resin composition, by having the above-described configuration, it has excellent alkali developability and excellent film thickness accuracy when a solution of the photosensitive resin composition is applied onto a support. Furthermore, the cured film can obtain excellent folding resistance and flame retardancy. Therefore, the said photosensitive resin composition can be used suitably for manufacture of the printed wiring board etc. by which folding resistance and a flame retardance are requested | required.
The present invention also provides: [2] The (A) binder polymer includes (a) an epoxy resin represented by the following general formula (1), (b) an unsaturated group-containing monocarboxylic acid, and (c) The photosensitive resin composition according to the above [1], comprising an acid-modified vinyl group-containing epoxy resin which is a reaction product with a basic carboxylic acid anhydride.

［一般式（１）中、Ｒ^１及びＲ^２は各々独立に、水素原子、炭素数１〜８のアルキル基、又は、アリール基を示し、ｎは０〜５０の整数を示す。なお、一般式（１）中、複数存在するＲ^１及びＲ^２はそれぞれ同一でも異なっていてもよい。］
（Ａ）バインダーポリマーとして上記特定の酸変性ビニル基含有エポキシ樹脂を含むことにより、感光性樹脂組成物は、優れたアルカリ現像性が得られるとともに、より優れた難燃性を有する硬化膜を形成可能となる。
また、本発明は、［３］更に（Ｅ）熱硬化剤を含有する上記［１］又は［２］記載の感光性樹脂組成物を提供する。感光性樹脂組成物が（Ｅ）熱硬化剤を含有することにより、感光性樹脂組成物を光硬化させた後、更に熱硬化させることで、得られる硬化膜の絶縁信頼性をより向上させることができる。
また、本発明は、［４］前記（Ｂ）リン含有化合物は、下記一般式（２）で表されるホスフィン酸塩を含上記［１］〜［３］のいずれかに記載の感光性樹脂組成物を提供する。

[In General Formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In the general formula (1), a plurality of R ¹ and R ² may be the same or different. ]
(A) By including the above-mentioned specific acid-modified vinyl group-containing epoxy resin as a binder polymer, the photosensitive resin composition provides excellent alkali developability and forms a cured film having more excellent flame retardancy. It becomes possible.
Moreover, this invention provides the photosensitive resin composition of the said [1] or [2] description which contains (3) thermosetting agent [3] further. When the photosensitive resin composition contains (E) a thermosetting agent, the photosensitive resin composition is photocured and then further thermoset to further improve the insulation reliability of the resulting cured film. Can do.
Moreover, this invention is [4] The photosensitive resin in any one of said [1]-[3] in which the said (B) phosphorus containing compound contains the phosphinic acid salt represented by following General formula (2). A composition is provided.

［一般式（２）中、Ａ及びＢは各々独立に、直鎖状又は分枝状の炭素数１〜６のアルキル基、又は、アリール基を示し、Ｍは、Ｍｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ及びＫからなる群より選択される少なくとも一種の金属を示し、ｍは１〜４の整数を示す。］
感光性樹脂組成物が上記一般式（２）で表されるホスフィン酸塩を含むことにより、得られる硬化膜の難燃性をより向上させることができる。
また、本発明は、［５］前記（Ｂ）リン含有化合物が、リン酸エステルを含む上記［１］〜［４］のいずれかに記載の感光性樹脂組成物を提供する。感光性樹脂組成物がリン酸エステルを含むことにより、得られる硬化膜の難燃性及び可撓性をより向上させることができる。なお、本発明の感光性樹脂組成物は、（Ｂ）リン含有化合物として、上記一般式（２）で表されるホスフィン酸塩と、上記リン酸エステルとの双方を含有することが好ましく、それにより、得られる硬化膜の難燃性と可撓性との双方を特に優れたものとすることができる。
また、本発明は、［６］更に（Ｆ）分散剤を含有する上記［１］〜［５］のいずれかに記載の感光性樹脂組成物を提供する。感光性樹脂組成物が（Ｆ）分散剤を含有することにより、感光性樹脂組成物の溶液を支持体上に塗工する際の膜厚精度をさらに向上することができる。
更に、本発明は、［７］フレキシブル基板上に永久マスクとなる硬化膜を形成するためのものである上記［１］〜［６］のいずれかに記載の感光性樹脂組成物を提供する。
本発明はまた、［８］支持体と、該支持体上に形成された上記［１］〜［７］のいずれかに記載の感光性樹脂組成物からなる感光性樹脂組成物層と、を備える感光性エレメントを提供する。かか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性樹脂組成物層を備えることにより、優れたアルカリ現像性が得られるとともに、優れた難燃性を有する硬化膜を形成可能である。

[In General Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, or Sb. , Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ]
When the photosensitive resin composition contains the phosphinic acid salt represented by the general formula (2), the flame retardancy of the obtained cured film can be further improved.
Moreover, this invention provides the photosensitive resin composition in any one of said [1]-[4] in which [5] said (B) phosphorus containing compound contains phosphate ester. When the photosensitive resin composition contains a phosphate ester, the flame retardancy and flexibility of the obtained cured film can be further improved. In addition, it is preferable that the photosensitive resin composition of this invention contains both the phosphinate represented by the said General formula (2) and the said phosphate ester as (B) phosphorus containing compound, Thus, both the flame retardancy and flexibility of the obtained cured film can be made particularly excellent.
Moreover, this invention provides the photosensitive resin composition in any one of said [1]-[5] containing [6] and (F) a dispersing agent further. When the photosensitive resin composition contains the (F) dispersant, the film thickness accuracy when the solution of the photosensitive resin composition is applied onto the support can be further improved.
The present invention further provides [7] the photosensitive resin composition according to any one of [1] to [6], which is for forming a cured film serving as a permanent mask on a flexible substrate.
The present invention also includes [8] a support and a photosensitive resin composition layer formed on the support and including the photosensitive resin composition according to any one of [1] to [7]. A photosensitive element is provided. According to such a photosensitive element, by providing the photosensitive resin composition layer composed of the photosensitive resin composition, an excellent alkali developability can be obtained, and a cured film having excellent flame retardancy can be formed. is there.

According to the present invention, curing having excellent alkali developability, excellent film thickness accuracy when coating a solution of a photosensitive resin composition on a support, and excellent folding resistance and flame retardancy. A photosensitive resin composition capable of forming a film and a photosensitive element using the same can be provided.
Further, according to the photosensitive resin composition of the present invention, since the flame retardancy of the cured film can be made sufficiently high without containing a halogen compound or an antimony compound, for example, the environmental load of a printed wiring board And toxicity can be reduced. In particular, when the photosensitive resin composition of the present invention is applied to a non-halogen-based or non-antimony-based flame retardant substrate, the above-described effects are more effectively exhibited.

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

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, (meth) acryloyl group corresponds to acryloyl group and it Means a methacryloyl group.

(Photosensitive resin composition)
The photosensitive resin composition of the present invention comprises (A) a binder polymer (hereinafter sometimes referred to as “component (A)”) and (B) an organic filler having a maximum particle size of 1 to 3 μm (hereinafter referred to as “phosphorus-containing compound”). , (Sometimes referred to as “component (B)”), (C) a photopolymerizable compound (hereinafter sometimes referred to as “(C) component”), and (D) a photopolymerization initiator (hereinafter referred to as “(D) ) Component ”)). The photosensitive resin composition of the present invention preferably further contains (E) a thermosetting agent (hereinafter, sometimes referred to as “component (E)”).
Hereinafter, each component contained in the photosensitive resin composition of the present invention will be described.

<(A) component: Binder polymer>
Examples of the binder polymer as the component (A) include acrylic resin, polyurethane, vinyl group-containing epoxy resin, epoxy resin, phenoxy resin, polyester, polyamide, polyimide, polyamideimide, polyesterimide, polycarbonate, melamine resin, polyphenylene sulfide, And known resins such as polyoxybenzoyl and acid-modified resins thereof having a carboxyl group in the molecule. These can be used alone or in combination of two or more.

The component (A) preferably contains a polymer having a carboxyl group in the molecule from the viewpoint of further improving alkali developability.
The binder polymer as component (A) includes (a) an epoxy resin represented by the following general formula (1), (b) an unsaturated group-containing monocarboxylic acid, (c) a polybasic carboxylic acid anhydride, It is preferable to include an acid-modified vinyl group-containing epoxy resin obtained as a reaction product.

［一般式（１）中、Ｒ^１及びＲ^２は各々独立に、水素原子、炭素数１〜８のアルキル基、又は、アリール基を示し、ｎは０〜５０の整数を示す。なお、一般式（１）中、複数存在するＲ^１及びＲ^２はそれぞれ同一でも異なっていてもよい。］
上記一般式（１）のような構造を有する化合物を用いて構成される酸変性ビニル基含有エポキシ樹脂を感光性樹脂組成物に含有させることにより、アルカリ現像性と難燃性との両立が可能となる。

[In General Formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In the general formula (1), a plurality of R ¹ and R ² may be the same or different. ]
By incorporating an acid-modified vinyl group-containing epoxy resin composed of a compound having a structure such as the general formula (1) into the photosensitive resin composition, both alkali developability and flame retardancy can be achieved. It becomes.

Specific examples of the (b) unsaturated bond-containing monocarboxylic acid constituting the acid-modified vinyl group-containing epoxy resin include, for example, acrylic acid, a dimer of acrylic acid, methacrylic acid, β-styrylacrylic acid, β- It is a reaction product of furfuryl acrylic acid, crotonic acid, α-cyanocinnamic acid, cinnamic acid, and a saturated or unsaturated dibasic acid anhydride and a (meth) acrylate derivative having one hydroxyl group in one molecule. Half-esters or half-esters that are a reaction product of a saturated or saturated dibasic acid and an unsaturated group-containing monoglycidyl compound can be used.
Half esters include, for example, succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, methylendomethylenetetrahydro Saturated or unsaturated dibasic acid anhydrides such as phthalic anhydride, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, glycerin di (meth) Acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, (meth) acrylic of phenylglycidyl ether Half esters obtained by reacting (meth) acrylate derivatives having one hydroxyl group in one molecule such as a salt with an equimolar ratio, or saturated or unsaturated dibasic acids (for example, succinic acid , Maleic acid, adipic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, itaconic acid, fumaric acid, etc.) and an unsaturated group-containing monoglycidyl compound (for example, glycidyl (meth) acrylate, etc.) A half ester obtained by reacting at a ratio.
These (b) morphanobonic acids can be used singly or in combination of two or more. Particularly preferred (b) monocarboxylic acid is acrylic acid.

  Specific examples of the (c) polybasic carboxylic acid anhydride constituting the acid-modified vinyl group-containing epoxy resin include, for example, maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride And methyltetrahydrophthalic anhydride.

The component (A) may include (a) an acid-modified vinyl group-containing epoxy resin constituted by using an epoxy resin other than the epoxy resin represented by the general formula (1). (A) As an epoxy resin other than the epoxy resin represented by the general formula (1), for example, a bisphenol type epoxy resin obtained by reacting bisphenol A type, bisphenol F type, hydrogenated bisphenol A type and epichlorohydrin, An amino group-containing, alicyclic or polybutadiene-modified epoxy resin is preferably used. In addition, novolak type epoxy resins obtained by reacting novolaks obtained by reacting phenol, cresol, halogenated phenols and alkylphenols with formaldehyde in the presence of an acidic catalyst and epichlorohydrin are also preferably used.
Examples of the bisphenol type epoxy resin include GY-260, 255 and XB-2615 manufactured by Ciba Geigy Co., and examples of the novolac type epoxy resin include YDCN-701 and 704 manufactured by Toto Kasei Co., Ltd. YDPN-638, 602, DEN-431, 439 manufactured by Dow Chemical Company, EPN-1299 manufactured by Ciba Geigy Co., Ltd., N-730, 770, 865, 665, 673, VH-4150 manufactured by Dainippon Ink & Chemicals, Inc. 4240, Nippon Kayaku Co., Ltd. EOCN-120, BREN etc. are mentioned.

  In addition to bisphenol type and novolak type epoxy resins, for example, salicylaldehyde-phenol or cresol type epoxy resins (Nippon Kayaku Co., Ltd. EPPN502H, FAE2500, etc.) are preferably used. Further, for example, Epicoat 828, 1007, 807 manufactured by Japan Epoxy Resin Co., Ltd., Epicron 840, 860, 3050 manufactured by Dainippon Ink & Chemicals, Inc., DER-330, 337, 361 manufactured by Dow Chemical Company, manufactured by Daicel Chemical Industries, Ltd. Celoxide 2021, TETRAD-X, C manufactured by Mitsubishi Gas Chemical Co., Ltd., EPB-13, 27 manufactured by Nippon Soda Co., Ltd., etc. can be used. Mixtures or block copolymers of these can also be used.

The acid-modified vinyl group-containing epoxy resin can also be purchased as a commercial product, for example, ZCR-1569H, ZCR-1596H, ZCR-1611H, ZCR-1610H (all manufactured by Nippon Kayaku Co., Ltd., trade names) are used. You can also
Moreover, it is also preferable that (A) component contains an acrylic resin. The acrylic resin can be obtained by radical polymerization using a vinyl copolymer compound such as (meth) acrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid. Examples include pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, and (meth) acrylic acid 2-ethylhexyl ester.

  As said vinyl type copolymer compound, you may use the compound obtained by copolymerizing the vinyl monomer which can be copolymerized with these with (meth) acrylic-acid alkylester and (meth) acrylic acid. Examples of such vinyl copolymer compounds include acrylamide such as diacetone acrylamide, esters of vinyl alcohol such as acrylonitrile and vinyl-n-butyl ether, (meth) acrylic acid tetrahydrofurfuryl ester, and (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 (meta) (Meth) acrylic monomers such as) acrylate, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid, and β-styryl (meth) acrylic acid , Maleic acid, maleic anhydride, maleic acid Examples include maleic monomers such as methyl, monoethyl maleate, and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, styrene, and vinyltoluene. It is done. These can be used alone or in combination of two or more.

  A copolymer in which an ethylenically unsaturated bond is introduced into the side chain and / or terminal of a vinyl copolymer compound that can be copolymerized with (meth) acrylic acid alkyl ester and (meth) acrylic acid is also suitable.

  Furthermore, the component (A) is an epoxy acrylate compound having two or more hydroxyl groups and an ethylenically unsaturated group, a diisocyanate compound, a diol compound having a carboxyl group, from the viewpoint of increasing the sensitivity of the photosensitive resin composition, A polyurethane compound obtained by reacting is preferred. Examples of preferable polyurethane compounds include UXE-3011, UXE-3012, and UXE-3024 (manufactured by Nippon Kayaku Co., Ltd.). Examples of such a polyurethane compound include compounds having a structure represented by the following general formula (3).

ここで、一般式（３）中、Ｒ^１１はエポキシアクリレートの残基、Ｒ^１２はジイソシアネートの残基、Ｒ^１３は炭素数１〜５のアルキル基、Ｒ^１４は水素原子又はメチル基を示す。なお、残基とは、原料成分から結合に供された官能基を除いた部分の構造をいう。また、式中に複数ある基は、それぞれ同一でも異なっていてもよい。

Here, in the general formula (3), R ¹¹ is an epoxy acrylate residue, R ¹² is a diisocyanate residue, R ¹³ is an alkyl group having 1 to 5 carbon atoms, and R ¹⁴ is a hydrogen atom or a methyl group. In addition, a residue means the structure of the part remove | excluding the functional group used for the coupling | bonding from the raw material component. In addition, a plurality of groups in the formula may be the same or different.

(A) It is preferable that the acid value of a component is 60-150 mgKOH / g, and it is more preferable that it is 80-120 mgKOH / g. When the acid value is less than 60 mgKOH / g, development with dilute alkali aqueous solution tends to be difficult, and when it exceeds 150 mgKOH / g, the insulation reliability, chemical resistance and plating resistance of the resulting cured film tend to be insufficient. There is.
In addition, the acid value of (A) component can be measured with the following method. First, after precisely weighing about 1 g of the resin solution as the component (A), 30 g of acetone is added to the resin solution to uniformly dissolve the resin solution. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N aqueous KOH solution. Then, the acid value is calculated from the titration result by the following formula.

なお、式中、Ａは酸価（ｍｇＫＯＨ／ｇ）を示し、ＶｆはＫＯＨ水溶液の滴定量（ｍＬ）を示し、Ｗｐは（Ａ）成分としての樹脂溶液の質量（ｇ）を示し、Ｉは（Ａ）成分としての樹脂溶液の不揮発分の割合（質量％）を示す。

In the formula, A represents the acid value (mgKOH / g), Vf represents the titration amount (mL) of the KOH aqueous solution, Wp represents the mass (g) of the resin solution as the component (A), and I represents (A) The ratio (mass%) of the non volatile matter of the resin solution as a component is shown.

  The weight average molecular weight of the component (A) is not particularly limited, but is preferably 1000 to 50000, more preferably 2000 to 30000, and more preferably 3000 to 15000 from the viewpoint of film properties and resolution. It is particularly preferred.

<(B) component: an organic filler having a maximum particle size of 1 to 3 μm comprising a phosphorus-containing compound>
The organic filler having a maximum particle size of 1 to 3 μm composed of the phosphorus-containing compound as the component (B) preferably contains a phosphinic acid salt represented by the following general formula (2) as the phosphorus-containing compound.

［一般式（２）中、Ａ及びＢは各々独立に、直鎖状又は分枝状の炭素数１〜６のアルキル基、又は、アリール基を示し、Ｍは、Ｍｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ及びＫからなる群より選択される少なくとも一種の金属を示し、ｍは１〜４の整数を示す。］
ここで、一般式（２）中のＡ及びＢの具体例としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、ｔｅｒｔ−ブチル基、ｎ−ペンチル基、フェニル基等が挙げられる。
また、上記リン含有化合物のうち８０質量％以上は、感光性樹脂組成物及び感光性エレメントに用いた際の信頼性の見地から、粒子の最大粒径が１〜３μｍであることが好ましく、１．５〜２．８μｍであることがより好ましい。この粒子の最大粒径が１μｍ以下になると、感光性樹脂組成物の膜厚精度が悪くなる傾向があり、高解像度のプリント配線板の製造が困難になる傾向があり、この粒子の最大粒径が３μｍを超えると、感光性樹脂組成物の耐折性が悪くなる傾向があり、フレキシブルプリント配線板の製造が困難になる。

[In General Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, or Sb. , Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ]
Here, specific examples of A and B in the general formula (2) include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-pentyl group, A phenyl group etc. are mentioned.
In addition, 80% by mass or more of the phosphorus-containing compound preferably has a maximum particle diameter of 1 to 3 μm from the viewpoint of reliability when used in the photosensitive resin composition and the photosensitive element. More preferably, the thickness is from 5 to 2.8 μm. When the maximum particle size of the particles is 1 μm or less, the film thickness accuracy of the photosensitive resin composition tends to deteriorate, and it tends to be difficult to produce a high-resolution printed wiring board. When the thickness exceeds 3 μm, the folding resistance of the photosensitive resin composition tends to deteriorate, and it becomes difficult to produce a flexible printed wiring board.

  In addition, there is no restriction | limiting in particular as a method of adjusting the maximum particle diameter of particle | grains, For example, it can adjust as follows. A dispersion in which an organic filler composed of a phosphorus-containing compound (B) is dispersed in a photopolymerizable compound as a solvent and / or a diluent is treated using a bead mill to pulverize the organic filler. It is preferable that the process temperature at this time is 50 degrees C or less. These processing apparatuses, processing conditions, and the like are appropriately selected from known methods according to the type or degree of dispersion of the organic filler, the type of dispersant, solvent, and the like. The maximum particle size can be measured with a particle size distribution meter (LS230, manufactured by Beckman Coulter, Inc.).

Said phosphinic acid salt can be used individually by 1 type or in combination of 2 or more types. Moreover, the said phosphinic acid salt can also be purchased as a commercial item, for example, EXOLIT OP 930, EXOLIT OP 935, EXOLIT OP 940 (all are the brand names made by Clariant Japan KK) can also be used.
When the photosensitive resin composition contains the phosphinate as the component (B), a cured film obtained by curing the photosensitive resin composition can obtain more sufficient flame retardancy. In addition, the phosphinate represented by the general formula (2) has a structure that is difficult to hydrolyze, and can effectively prevent the generation of ionic impurities that reduce electrical insulation, so that the cured film is excellent. It can have insulation reliability.

  Moreover, it is also preferable that the phosphorus-containing compound as the component (B) contains a phosphate ester. Specific examples of phosphate esters include, for example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 1,3-dihydroxybenzene / trichlorophosphine polycondensate phenol Examples thereof include a condensate and a phenol condensate of 2,2-bis (p-hydroxyphenyl) propane / trichlorophosphine oxide polycondensate. These are commercially available, for example, TPP, TCP, TXP, CDP, XDP, CR-733S, CR-741, CR-747 (all are trade names manufactured by Daihachi Chemical Industry Co., Ltd.), PFR FP-600 and FP-700 (both manufactured by ADEKA Corporation, trade names) and the like.

When the photosensitive resin composition contains a phosphate ester as the component (B), the flame retardancy of a cured film obtained by curing the photosensitive resin composition can be further improved. Moreover, since the phosphate ester functions as a plasticizer, the flexibility of the cured film can be further improved.
As the component (B), one of the phosphinic acid salt represented by the general formula (2) and the phosphoric acid ester may be used alone, but at least the phosphine represented by the general formula (2). It is preferable to use an acid salt, and it is particularly preferable to use both the phosphinic acid salt represented by the general formula (2) and the phosphate ester. Moreover, as a (B) component, well-known phosphorus containing compounds other than these can also be used.

<(C) component: photopolymerizable compound>
(C) As a photopolymerizable compound, for example, a bisphenol A-based (meth) acrylate compound; a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid; a glycidyl group-containing compound with an α, β- Compounds obtained by reacting an unsaturated carboxylic acid; urethane monomers or urethane oligomers such as (meth) acrylate compounds having a urethane bond, and in addition to these, nonylphenoxypolyoxyethylene acrylate; γ-chloro-β- Phthalic acid compounds such as hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl-o-phthalate; (meth) acrylic acid alkyl ester, Examples include EO-modified nonylphenyl (meth) acrylate It is. These can be used individually by 1 type or in combination of 2 or more types.

Examples of bisphenol A-based (meth) acrylate compounds 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, etc. Can be mentioned.
Examples of 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-((meth)) 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) acryloxy nonaethoxy) ) 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 and 2,2-bis (4-((meth) acryloxyhexa) Decaethoxy) phenyl) propane and the like. Among these, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). Bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These can be used individually by 1 type or in combination of 2 or more types.

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic) Xinonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl) propane, 2,2-bis ( 4-((meth) acryloxytetradecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl) propane and 2,2-bis (4-((meth)) And acryloxyhexadecapropoxy) phenyl) propane. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane, Examples include 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane. These can be used individually by 1 type or in combination of 2 or more types.

Examples of the compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol include 2 to 14 polyethylene glycol di (meth) acrylate propylene groups having 2 to 14 ethylene groups. 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, trimethylol Propane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO / PO modified trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) acrylate Examples include relate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These can be used individually by 1 type or in combination of 2 or more types.
“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. Further, “EO modified” means having a block structure of ethylene oxide units (—CH ₂ CH ₂ O—), and “PO modified” means propylene oxide units (—CH ₂ CH ₂ CH ₂ O—), It means having a block structure of (—CH ₂ CH (CH ₃ ) O—), (—CH (CH ₃ ) CH ₂ O—).

  Examples of the compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth) acryloxy- 2-hydroxy-propyloxy) phenyl and the like. Examples of the α, β-unsaturated carboxylic acid include (meth) acrylic acid. These can be used individually by 1 type or in combination of 2 or more types.

Examples of urethane monomers include (meth) acrylic monomers having an OH group at the β-position and diisocyanate compounds such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction products, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO or PO-modified urethane di (meth) acrylate, carboxyl group-containing urethane (meth) acrylate, etc. It is done. These can be used individually by 1 type or in combination of 2 or more types.
As a urethane oligomer, the compound of the weight average molecular weight 2000-100000 which has a urethane bond and an ethylenically unsaturated group in a molecule | numerator is mentioned, for example. As the urethane oligomer, for example, a urethane compound having a urethane bond derived from a reaction between a hydroxyl group at a terminal of a polycarbonate compound and / or a polyester compound and an isocyanate group of a diisocyanate compound and having an isocyanate group at a plurality of terminals, Examples thereof include compounds obtained by reacting a compound having a hydroxyl group and an ethylenically unsaturated group.
Furthermore, examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester. It is done. These can be used individually by 1 type or in combination of 2 or more types.
The photosensitive resin composition preferably contains a bisphenol A (meth) acrylate compound as the component (C) from the viewpoint of improving the resolution of the photosensitive resin composition and the flexibility of the cured film, and among them, alkyleneoxy It is more preferable to include a bisphenol A-based di (meth) acrylate compound having a group.

<(D) component: Photopolymerization initiator>
Specific examples of the photopolymerization initiator as component (D) include, for example, benzophenone, 4,4′-bis (dimethylamino) benzophenone (Michler ketone), 4,4′-bis (diethylamino) benzophenone, 4-methoxy- 4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-morpholinophenone) -butanone-1,2-ethylanthraquinone, phenanthrenequinone and other aromatic ketones, alkylanthraquinone and other quinones, benzoin methyl ether, Benzoin ethers such as benzoin ethyl ether and benzoin phenyl ether, benzoins such as methyl benzoin and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 9-phenylacridine, 1,7-bis (9,9′-acridinyl) hepta And acridine derivatives such as N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds. These can be used individually by 1 type or in combination of 2 or more types.

<(E) component: thermosetting agent>
Specific examples of the thermosetting agent as component (E) include thermosetting compounds such as epoxy resins, phenol resins, urea resins, and melamine resins. Examples of the epoxy resin include bisphenol A type tertiary fatty acid-modified polyol epoxy resin; diglycidyl esters such as diglycidyl phthalate and diglycidyl tetrahydrophthalate, and diglycidyl amines such as diglycidyl aniline and diglycidyl toluidine. Etc. You may use these individually by 1 type or in combination of 2 or more types.
Moreover, the block isocyanate compound which is a latent thermosetting agent can also be used as a thermosetting agent which is (E) component. Examples of the blocked isocyanate compound include polyisocyanate compounds blocked with a blocking agent such as an alcohol compound, a phenol compound, ε-caprolactam, an oxime compound, and an active methylene compound. Examples of the polyisocyanate compound to be blocked include 4,4-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene 1,5-diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate, Aromatic polyisocyanates such as 2,4-tolylene dimer, aliphatic polyisocyanates such as hexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate, and alicyclic polyisocyanates such as bicycloheptane triisocyanate An aromatic polyisocyanate is preferable from the viewpoint of heat resistance, and an aliphatic polyisocyanate or an alicyclic polyisocyanate is preferable from the viewpoint of preventing coloring.

<(F) component: dispersant>
The photosensitive resin composition of the present invention contains an organic filler having a maximum particle size of 1 to 3 μm composed of an organic phosphorus compound as the component (B), and further improves the dispersibility of the component (B) ( F) A dispersant may be included. Examples of the component (F) include a copolymer compound of polyalkylene glycol and polycaprolactone.

In order for the photosensitive resin composition to have good flame retardancy, the content of the component (A) in the photosensitive resin composition is 35 to 70% by mass based on the total solid content of the photosensitive resin composition. It is preferable that it is 40-65 mass%. When the content of the component (A) is less than 35% by mass, the flame retardancy of the cured film tends to decrease, and when it exceeds 70% by mass, development with a dilute aqueous alkali solution tends to be difficult.
In order to obtain good flame retardancy, the phosphorus content in the photosensitive resin composition is preferably 1.5 to 5.0% by mass based on the total solid content of the photosensitive resin composition. 2.0 to 4.5% by mass is more preferable. If the phosphorus content is less than 1.5% by mass, the flame retardancy of the cured film tends to decrease, and if it exceeds 5.0% by mass, the folding resistance and insulation reliability of the cured film decrease. Tend.
The component (B) is preferably contained so that the phosphorus content is in the above range. Moreover, when using the phosphinic acid salt represented by the said General formula (2) as (B) component, the content should be 5-20 mass% on the basis of the solid content whole quantity of the photosensitive resin composition. Preferably, it is 7-15 mass%, More preferably, it is 9-12 mass%. If this content is less than 5% by mass, the flame retardancy of the cured film tends to be reduced, and if it exceeds 20% by mass, the flexibility and film thickness accuracy of the cured film tend to be reduced.
Moreover, when using phosphate ester in combination with a phosphinic acid salt as (B) component, the content of the phosphate ester shall be 1-20 mass% on the basis of the solid content whole quantity of the photosensitive resin composition. preferable. When this content exceeds 20 mass%, there exists a tendency for an electric corrosion resistance and bleed-out property (a bleeding of the photosensitive resin composition) to worsen.

The content of the component (C) is preferably 7 to 30% by mass, and 10 to 25% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of resolution and flame retardancy. It is more preferable. When the content of the component (C) is less than 7% by mass, the resolution tends to be inferior, and when it exceeds 30% by mass, the flame retardancy of the cured film tends to decrease.
The content of the component (D) is preferably 0.1 to 10% by mass and preferably 0.2 to 5% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of photosensitivity. Is more preferable.
When the photosensitive resin composition contains the component (E), the content is 5 to 20% by mass based on the total solid content of the photosensitive resin composition from the viewpoint of flame retardancy and insulation reliability. It is preferably 8 to 15% by mass.
When the photosensitive resin composition contains the component (F), from the viewpoint of the content, film thickness accuracy, and folding resistance, 0.001 to 10% by mass based on the total solid content of the photosensitive resin composition Preferably, it is 0.01 to 5% by mass, and more preferably 0.1 to 3% by mass.

  In addition, the photosensitive resin composition of the present invention includes a dye such as malachite green, a photochromic agent such as leuco crystal violet, a plasticizer such as a thermochromic inhibitor or p-toluenesulfonamide, phthalocyanine blue, if necessary. Phthalocyanine-based organic pigments such as azo-based or inorganic pigments such as titanium dioxide, fillers made of inorganic pigments such as silica, alumina, talc, calcium carbonate or barium sulfate, antifoaming agents, stabilizers, adhesion-imparting agents , A leveling agent, an antioxidant, a fragrance, an imaging agent, or the like. These components are each preferably contained in an amount of about 0.01 to 20% by mass based on the total solid content of the photosensitive resin composition. Moreover, said component can be used individually by 1 type or in combination of 2 or more types.

  Furthermore, the photosensitive resin composition of the present invention may contain a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether or the like as necessary. It can melt | dissolve in a mixed solvent and can apply | coat as a solution of solid content about 30-70 mass%.

The photosensitive resin composition of the present invention as described above is applied as a liquid resist on a metal surface such as copper, a copper-based alloy, iron, and an iron-based alloy, and then dried, and a protective film is provided as necessary. It can be used by coating or in the form of a photosensitive element described later.
Moreover, the board | substrate which formed the cured film which consists of the photosensitive resin composition of this invention on flexible base materials, such as a polyimide, has the outstanding flame retardance. The photosensitive resin composition of the present invention does not contain a halogen-based compound or an antimony-based compound, and can make the cured film sufficiently high in flame retardancy. For example, it reduces the environmental load and toxicity of a printed wiring board. It becomes possible to do.
Further, the photosensitive resin composition of the present invention can form a cured film having sufficient flame retardancy with high resolution, and can form a cured film having sufficient flexibility. It is preferably used for forming a permanent mask for a flexible printed wiring board.

(Photosensitive element)
Next, the photosensitive element using the photosensitive resin composition which apply | coated the photosensitive resin solution described above is demonstrated. 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 10 and a photosensitive resin composition layer 14 provided on the support 10. The photosensitive resin composition layer 14 is a layer made of the above-described photosensitive resin composition of the present invention. Moreover, the photosensitive element 1 of this invention may coat | cover the surface F1 on the opposite side to the support body 10 on the photosensitive resin composition layer 14 with a protective film.
The photosensitive resin composition layer 14 is prepared by dissolving the photosensitive resin composition of the present invention in the above solvent or mixed solvent to obtain a solution having a solid content of about 30 to 70% by mass, and then applying the solution onto the support 10. Is preferably formed.
Although the thickness of the photosensitive resin composition layer 14 varies depending on the application, it is preferably 10 to 100 μm and more preferably 20 to 60 μm in thickness after drying after removing the solvent by heating and / or hot air blowing. preferable. If the thickness is less than 10 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the above-described effects produced by the present invention tend to be reduced, and in particular, flexibility and resolution tend to decrease.

Examples of the support 10 included in the photosensitive element 1 include a polymer film having heat resistance and solvent resistance such as polyester such as polyethylene terephthalate, polypropylene, and polyethylene.
The thickness of the support 10 is preferably 5 to 100 μm, and more preferably 10 to 30 μm. If the thickness is less than 5 μm, the support tends to be broken when the support is peeled off before development, and if it exceeds 100 μm, the resolution and flexibility tend to decrease.
The photosensitive element 1 consisting of two layers of the support 10 and the photosensitive resin composition layer 14 as described above or the photosensitive element consisting of three layers of the support 10, the photosensitive resin composition layer 14 and the protective film is as follows. For example, it may be stored as it is, or it can be wound around a roll core and stored after interposing a protective film.

The method for forming a resist pattern using the photosensitive element according to the present invention includes a removing step of removing the protective film from the photosensitive element as necessary, a photosensitive resin composition layer, and a support. A lamination step of laminating on the circuit forming substrate in this order, and an actinic ray is irradiated to a predetermined portion of the photosensitive resin composition layer through a support, if necessary, to form a photocured portion on the photosensitive resin composition layer. And an exposure step for removing the photosensitive resin composition layer other than the photocured portion. The circuit-forming substrate is an insulating layer and a conductor layer (copper, copper-based alloy, iron-based alloy such as nickel, chromium, iron, stainless steel, preferably copper, copper-based alloy) formed on the insulating layer. , Made of an iron-based alloy).
Examples of the laminating method in the laminating step after the removing step of removing the protective film as necessary include a method of laminating by pressing the photosensitive resin composition layer on the circuit forming substrate while heating. The atmosphere during the lamination is not particularly limited, but the lamination is preferably performed under reduced pressure from the viewpoint of adhesion and followability. The surface to be laminated is usually the surface of the conductor layer of the circuit forming substrate, but may be a surface other than the conductor layer.
The heating temperature of the photosensitive resin composition layer is preferably 70 to 130 ° C., the pressure bonding pressure is preferably about 0.1 to 1.0 MPa, and the ambient atmospheric pressure is more preferably 4000 Pa or less. These conditions are not particularly limited. 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.

After the lamination is completed in this manner, a photocured portion is formed by irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays in the exposure step. Examples of the method for forming the photocured portion include a method of irradiating an actinic ray in an image form through a negative or positive mask pattern called an artwork. At this time, when the support present on the photosensitive resin composition layer is transparent, it can be irradiated with actinic rays as it is, but when opaque, the photosensitive resin composition is removed after removing the support. Irradiate the layer with actinic rays.
As the light source of actinic light, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that can effectively emit ultraviolet rays can be used. Moreover, what can radiate | emit visible light effectively, such as a flood bulb for photography, a solar lamp, can also be used.
Next, after exposure, when a support is present on the photosensitive resin composition layer, after removing the support, in the development process, a photosensitive resin other than the photocured portion by wet development, dry development, or the like. The composition layer is removed and developed to form a resist pattern.
In the case of wet development, development is performed using a developer such as an alkaline aqueous solution by a known method such as spraying, rocking immersion, brushing, or scraping. As the developer, a developer that is safe and stable and has good operability is used. For example, a dilute solution (1 to 5% by mass aqueous solution) of sodium carbonate at 20 to 50 ° C. is used.

For example, when the resist pattern obtained by the above-described forming method is used as a solder resist for a printed wiring board, a high pressure is used for the purpose of improving solder heat resistance, chemical resistance, etc. as the solder resist after completion of the development process. It is preferable to perform ultraviolet irradiation with a mercury lamp or heating with an oven.
In the case of irradiating ultraviolet rays, the irradiation amount can be adjusted as necessary. For example, the irradiation can be performed at an irradiation amount of about 0.2 to 10 J / cm ² . Moreover, when heating, it is preferable to carry out for about 15 to 90 minutes in the range of about 100-170 degreeC. Furthermore, both ultraviolet irradiation and heating may be performed, and after one of them is performed, the other can be performed.
The resist pattern obtained by the above-described forming method is preferably used as a permanent mask formed on a printed wiring board.
Since the cured film formed from the photosensitive resin composition of the present invention has excellent flame retardancy, it is effective as a permanent mask for a printed wiring board that also serves as a protective film for wiring after soldering to the substrate. is there.

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.
(Examples 1-3, Comparative Examples 1-3)
(Preparation of organic filler)
As component (B), phosphinic acid salt (manufactured by Clariant Japan Co., Ltd., trade name “EXOLIT OP935”, phosphorus content = 23 mass%), urethane oligomer (manufactured by Kyoeisha Chemical Co., Ltd., trade name “UF-TC4-55”) , A polyester compound having a hydroxyl group at the terminal, a product obtained by reacting an organic isocyanate and 2-hydroxyethyl acrylate, a weight average molecular weight Mw = 20000) and the component (F), methanol and toluene are mixed, and organic A filler dispersion was prepared. This was processed at a processing temperature of 50 ° C. or lower using a bead mill (bead diameter 0.8 mm, filling rate 80 volume%, rotation speed 20 m / s), and the organic filler was pulverized. (B-1) to (B-4) were obtained.
About the obtained organic filler dispersion liquid (B-1)-(B-4), the maximum particle size was measured, respectively, using the particle size distribution analyzer (the Beckman Coulter company make, LS230). Table 1 shows the processing time of the bead mill and the maximum particle size of the organic filler after the processing.

A solution of the photosensitive resin composition was obtained by mixing the above (B-1) to (B-4) and the other components shown in Table 1 at a solid content ratio (mass basis) shown therein. .
In Table 1, component (A) is biphenyl type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name “ZCR-1569H”, novolak type acid-modified vinyl group-containing epoxy resin having a biphenyl skeleton, acid value = 98 mgKOH / G, Mw = 4500).
The component (B) is a phosphinate (manufactured by Clariant Japan, trade name “EXOLIT OP935”, phosphorus content = 23 mass%).
The component (C) is 2,2-bis (4-((meth) acryloxypentaethoxy) phenyl) propane (made by Shin-Nakamura Chemical Co., Ltd., trade name “BPE-10”).
The component (D) is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name “I-369” manufactured by Ciba Specialty Chemicals).
The component (E) is a 75% by mass methyl ethyl ketone solution of isocyanurate methyl ethyl ketone oxime block based on hexamethylene diisocyanate as a base isocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., trade name “BL3175”).
Component (F) is a trade name “BYK-903” manufactured by Big Chemie Japan Co., Ltd.

数値は配合量：ｇ（固形分）

The numerical value is blending amount: g (solid content)

[Production of photosensitive element]
The photosensitive resin composition solutions of Examples 1 to 3 and Comparative Examples 1 to 3 were uniformly distributed on a 16 μm-thick polyethylene terephthalate film (trade name “G2-16”, manufactured by Teijin Limited) as a support. The photosensitive resin composition layer was formed by applying to the substrate and dried at 100 ° C. for 10 minutes using a hot air convection dryer. The film thickness after drying of the photosensitive resin composition layer was 38 μm.
Next, a polyethylene film (manufactured by Tamapoly Co., Ltd., trade name “NF-13”) is bonded as a protective film on the surface of the photosensitive resin composition layer opposite to the side in contact with the support, and photosensitive. Got the element.

[Preparation of evaluation laminate]
The copper surface of a flexible printed wiring board substrate (trade name “F30VC1” manufactured by Nikkan Kogyo Co., Ltd.) obtained by laminating a 18 μm thick copper foil on a polyimide base material was acid washed with hydrochloric acid, washed with water, and dried.
Using a continuous vacuum laminator (trade name “HLM-V570”, manufactured by Hitachi Chemical Co., Ltd.) on this flexible printed wiring board substrate, a heat shoe temperature of 100 ° C., a laminating speed of 0.5 m / min, and an atmospheric pressure of 4000 Pa or less. Then, under the condition of a pressure bonding pressure of 0.3 MPa, the obtained photosensitive element was laminated with the photosensitive resin composition layer on the copper foil side while peeling the polyethylene film to obtain a laminate for evaluation.

[Evaluation of light sensitivity]
A phototool having a stove 21-step tablet as a negative is brought into intimate contact with the obtained laminate for evaluation, and a stow 21-step tablet using a HMW-201GX type exposure machine manufactured by Oak Manufacturing Co., Ltd. The exposure was performed with an energy amount such that the number of remaining steps after development was 8.0.
Next, after standing for 1 hour at room temperature (25 ° C.) and peeling off the PET film, development was performed by spraying with a 1% by mass aqueous sodium carbonate solution at 30 ° C. for 40 seconds, and heating (drying) at 80 ° C. for 10 minutes. . The above-mentioned energy amount at the time of exposure was used as a numerical value for evaluating the photosensitivity. The lower this value, the higher the photosensitivity. The results are shown in Table 2.

[Resolution evaluation]
A phototool having a stove 21-step tablet and a phototool having a wiring pattern with a line width / space width of 30/30 to 200/200 (unit: μm) as a negative for resolution evaluation are provided on the evaluation laminate. Using the above-described exposure apparatus, the exposure was performed with an energy amount such that the number of remaining steps after development of the stove 21-step tablet was 8.0.
Subsequently, after leaving still at room temperature for 1 hour and peeling off a PET film, it developed by spraying 1 mass% sodium carbonate aqueous solution of 30 degreeC for 40 second, and heated (dried) at 80 degreeC for 10 minutes. Here, the resolution was evaluated based on the smallest value (unit: μm) of the space width between the line widths in which a rectangular resist shape was obtained by development processing. It shows that it is excellent in the resolution, so that this value is small. The results are shown in Table 2.

[Production of evaluation FPC]
On the obtained laminate for evaluation, a photo tool having a stove 21-step tablet and a photo tool having a wiring pattern as a negative for reliability evaluation of the coverlay are brought into close contact, and the exposure machine described above is used. Then, exposure was performed with an energy amount such that the number of remaining steps after development of the stove 21-step tablet was 8.0.
Next, after standing at room temperature for 1 hour, the polyethylene terephthalate on the laminate was peeled off, spray development was performed under the same developer and development conditions as in the photosensitivity evaluation, and heated (dried) at 80 ° C. for 10 minutes. . Subsequently, an FPC for evaluation in which a coverlay was formed by performing ultraviolet irradiation with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further performing heat treatment at 160 ° C. for 60 minutes. Got.

[Evaluation of flexibility (folding resistance)]
The FPC for evaluation obtained as described above was repeatedly bent 180 ° by goby folding, and the number of times until a crack occurred in the cured film at that time was determined and evaluated according to the following criteria. The presence or absence of cracks was confirmed with a microscope. The results are shown in Table 2.
A: No cracks are observed in the cured film even if it is bent five times or more,
B: The number of times of bending until cracking is 3 to 4 times,
C: The number of times until a crack is generated is 2 or less.

[Evaluation of flame retardancy]
The copper foil of the copper foil-clad laminate (manufactured by Nippon Steel Chemical Co., Ltd., trade name “ESPANEX MB”) was removed by etching to obtain a PI (polyimide) film having a thickness of 25 μm. Next, on both sides of the PI film, using a continuous vacuum laminator (manufactured by Hitachi Chemical Co., Ltd., trade name “HLM-V570”), a heat shoe temperature of 100 ° C., a laminating speed of 0.5 m / min, and an atmospheric pressure of 4000 Pa or less. Then, under the condition of pressure bonding pressure of 0.3 MPa, the above photosensitive element was laminated with the photosensitive resin composition layer on the PI film side while peeling the polyethylene film to obtain a laminate.
Next, using a HNW-201GX type exposure machine manufactured by Oak Manufacturing Co., Ltd., exposure of the photosensitive resin composition layer of the photosensitive element described above was performed with a remaining step number of 8 after development of the stove 21 step tablet. The above energy amount was set to 0.0. Then, after leaving still at room temperature for 1 hour and peeling a polyethylene terephthalate film from a laminated body, the 1 mass% sodium carbonate aqueous solution of 30 degreeC is sprayed on a laminated body for 40 second, and it develops, and it heats at 80 degreeC for 10 minutes (Dry).
Next, the photosensitive resin composition layer of the laminate is irradiated with ultraviolet rays with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further subjected to heat treatment at 160 ° C. for 60 minutes. A flame retardant evaluation sample in which a coverlay was formed was obtained.
This flame retardant evaluation sample was subjected to a thin material vertical combustion test based on the UL94 standard. Evaluation was expressed as VTM-0, VTM-1, or VTM-2 based on the UL94 standard. The results are shown in Table 2. In addition, “NOT” in Table 2 indicates that the test piece for flame retardancy evaluation did not correspond to VTM-0, VTM-1, and VTM-2 in the combustion test and was completely burned.

[Evaluation of film thickness accuracy]
The photosensitive resin composition solutions of Examples 1 to 3 and Comparative Examples 1 to 3 were separately applied onto a 16 μm-thick polyethylene terephthalate film (trade name “G2-16” manufactured by Teijin Limited) as a support. As a result, a photosensitive resin composition layer was formed and dried at 100 ° C. for 10 minutes using a hot air convection dryer. The dried film was measured in the width direction with a film thickness measuring instrument (manufactured by Nikon, MH-15M), and the integrated R value of the deflection width was evaluated. A smaller integrated R value means better film thickness accuracy. The results are shown in Table 2.

[Evaluation of thixotropy]
The viscosity of the photosensitive resin composition solutions of Examples 1 to 3 and Comparative Examples 1 to 3 was measured using a viscometer (trade name “VISCONIC” manufactured by Tokyo Keiki Co., Ltd.) at a measurement temperature of 30 ° C. and a rotor rotation speed of 0 The measurement was performed at 5 rpm and 5 rpm, and the ratio of the viscosity at 0.5 rpm to the viscosity at 5 rpm was calculated, and this was defined as thixotropy. The closer this value is to 1, the lower the thixotropy and the better. The results are shown in Table 2.

  As is clear from Table 2, Examples 1 to 3 using an organic filler in which the maximum particle size of the phosphorus-containing compound is in the range of 1 to 3 μm are excellent in bending resistance of the cured film and have sufficient thixotropy. The film thickness accuracy was good. Examples 1 and 2 were particularly excellent in film thickness accuracy, and Examples 1 and 3 were particularly excellent in flame retardancy. On the other hand, Comparative Examples 1-3 were inferior to an Example in either folding resistance or film thickness precision.

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 10 ... Support body, 14 ... Photosensitive resin composition layer.

Claims (8)

(A) a binder polymer;
(B) an organic filler having a maximum particle size of 1 to 3 μm composed of a phosphorus-containing compound;
(C) a photopolymerizable compound;
(D) a photopolymerization initiator;
The photosensitive resin composition containing this. The (A) binder polymer is a reaction of (a) an epoxy resin represented by the following general formula (1), (b) an unsaturated group-containing monocarboxylic acid, and (c) a polybasic carboxylic acid anhydride. The photosensitive resin composition of Claim 1 containing the acid-modified vinyl group containing epoxy resin which is a product.

[In General Formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and n represents an integer of 0 to 50. In the general formula (1), a plurality of R ¹ and R ² may be the same or different. ]   The photosensitive resin composition according to claim 1 or 2, further comprising (E) a thermosetting agent. The photosensitive resin composition in any one of Claims 1-3 in which the said (B) phosphorus containing compound contains the phosphinic acid salt represented by following General formula (2).

[In General Formula (2), A and B each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, or Sb. , Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K. m represents an integer of 1 to 4. ]   The photosensitive resin composition in any one of Claims 1-4 in which the said (B) phosphorus containing compound contains phosphate ester.   Furthermore, (F) The photosensitive resin composition in any one of Claims 1-5 containing a dispersing agent.   The photosensitive resin composition in any one of Claims 1-6 for forming the cured film used as a permanent mask on a flexible substrate.   A photosensitive element provided with a support body and the photosensitive resin composition layer which consists of the photosensitive resin composition in any one of Claims 1-7 formed on this support body.

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