JP6639827B2 - Curable resin composition, dry film, cured product and printed wiring board - Google Patents

Description

  The present invention relates to a curable resin composition, a dry film, a cured product, and a printed wiring board.

  2. Description of the Related Art With the rapid progress of semiconductor components in recent years, electronic devices tend to be smaller and lighter, have higher performance, and have more functions. Following this trend, printed wiring boards have also been increasing in density and surface mounting of components. In the production of a high-density printed wiring board, a photosensitive composition is generally used for forming a solder resist or the like, and a dry film type composition or a liquid composition has been developed. Among these, alkali-developing photosensitive compositions using a dilute aqueous alkali solution as a developing solution have become mainstream in consideration of environmental problems, and several composition systems have been proposed in the past. For example, Patent Document 1 describes a photosensitive composition containing a specific active energy ray-curable resin, a photopolymerization initiator, and a diluent. Patent Literature 2 further includes an alkali-developable resin, a heat-reactive compound, and a photobase generator, and the alkali-developable resin and the heat-reactive compound are subjected to an addition reaction by selective light irradiation. A resin composition capable of forming a negative pattern by development is described.

  In recent years, among printed wiring boards, IC packages have become increasingly lighter, thinner and shorter due to the rise of smartphones and tablet PCs.

JP-A-61-243869 (Claims) WO2013 / 172435A1 (Claims)

  As the IC package becomes lighter and thinner, the photosensitive composition used for the solder resist of the IC package needs to have a smaller space between lines and a smaller opening diameter. Therefore, a higher resolution is required. Further, as a property after curing, improvement in PCT resistance (pressure cooker test resistance), which is also referred to as wet heat resistance, is also required.

  Therefore, an object of the present invention is to provide a curable resin composition, a dry film, a cured product, and a printed wiring board which are excellent in resolution and PCT resistance of the cured product.

  The present inventors have studied using a photosensitive composition utilizing photopolymerization, such as the photosensitive composition described in Patent Document 1, for example, in order to solve the above problem. Progress, that is, halation is likely to occur, and there is a limit to improvement in resolution.

  Further, in the case of the resin composition described in Patent Document 2, since an organic compound having an ethylenically unsaturated double bond is not required, PCT resistance is improved, and halation does not easily occur. And the pattern collapsed (this is called resin flow). This phenomenon occurs remarkably, particularly when heat treatment is performed. When the pattern becomes fine, the collapse between the lines causes the size of the line and the size of the opening to largely deviate from the design value, thereby hindering improvement in resolution.

  As a result of further investigations by the present inventors, it contains an alkali-developable resin having an ethylenically unsaturated double bond, a specific photopolymerization initiator, a thermosetting component, and silica, and is substantially ethylenic. By finding that the curable resin composition does not contain an organic compound having an ethylenically unsaturated double bond other than the alkali developable resin having an unsaturated double bond, the above problem can be solved, and the present invention is completed. Reached.

  That is, the curable resin composition of the present invention comprises (A) an alkali developable resin having an ethylenically unsaturated double bond, (B) a photopolymerization initiator that generates a radical and a base, (C) a thermosetting component, And (D) a curable resin composition containing silica, wherein (E) an ethylenically unsaturated double bond is substantially contained in addition to the (A) alkali-developable resin having an ethylenically unsaturated double bond. Characterized in that it does not contain an organic compound.

  In the curable resin composition of the present invention, the content of the silica (D) is preferably 30 to 80% by mass based on the solid content of the entire composition.

  In the curable resin composition of the present invention, the silica (D) is preferably surface-treated.

  In the curable resin composition of the present invention, the thermosetting component (C) is preferably an epoxy compound.

  The curable resin composition of the present invention is preferably used for forming a solder resist.

  The dry film of the present invention has a resin layer obtained from the curable resin composition.

  The cured product of the present invention is obtained by curing the curable resin composition or the resin layer of the dry film.

  A printed wiring board according to the present invention includes the cured product.

  According to the present invention, it is possible to provide a curable resin composition, a dry film, a cured product, and a printed wiring board excellent in resolution and PCT resistance of the cured product.

The curable resin composition of the present invention comprises (A) an alkali developable resin having an ethylenically unsaturated double bond (hereinafter sometimes abbreviated as (A) an alkali developable resin), (B) a radical and A curable resin composition containing a photopolymerization initiator that generates a base (hereinafter sometimes abbreviated as (B) photopolymerization initiator), (C) a thermosetting component, and (D) silica. And (E) substantially no organic compound having an ethylenically unsaturated double bond other than the alkali-developable resin having an ethylenically unsaturated double bond. The curable resin composition of the present invention can form a negative pattern by alkali development by selective light irradiation. Here, pattern formation refers to forming a patterned cured product, that is, a pattern layer.
Since the resin layer comprising the curable resin composition of the present invention contains (B) a photopolymerization initiator, radicals and bases are generated by light irradiation. As a result, (A) the alkali developable resin having an ethylenically unsaturated double bond and another (A) alkali developable resin having an ethylenically unsaturated double bond are polymerized, and (A) the ethylenically unsaturated double bond is polymerized. An alkali-developable resin having a saturated double bond and the thermosetting component (C) undergo an addition reaction to cure the resin layer to a deep portion. Therefore, the pattern can be formed by irradiating the curable resin composition with light in a pattern and then performing alkali development to remove unirradiated portions.

  In the curable resin composition of the present invention, although the detailed mechanism is not clear, the alkali-developable resin has an ethylenically unsaturated bond, and (B) the photopolymerization initiator is not only a base by light irradiation but also a base. Since radicals are also generated, it is considered that pattern collapse after development is suppressed due to radical polymerization. Further, it is considered that halation hardly occurs by not containing (E) an organic compound having an ethylenically unsaturated double bond in addition to (A) an alkali developable resin having an ethylenically unsaturated double bond substantially. . Further, a curable resin composition containing a general (E) organic compound having an ethylenically unsaturated double bond is susceptible to hydrolysis contained in the (E) organic compound having an ethylenically unsaturated double bond. Although it has been difficult to improve the PCT resistance due to the ester bond, in the present invention, since the (E) organic compound having an ethylenically unsaturated double bond is not substantially contained, the cured product has an improved PCT resistance.

  Hereinafter, each component of the curable resin composition of the present invention will be described.

[(A) Alkali developable resin having ethylenically unsaturated double bond]
(A) The alkali-developable resin contains at least one functional group of a phenolic hydroxyl group, a thiol group and a carboxyl group, and an ethylenically unsaturated double bond, and is a resin that can be developed with an alkaline solution. Preferable examples include a photosensitive resin having two or more phenolic hydroxyl groups, a carboxyl group-containing photosensitive resin, a photosensitive resin having a phenolic hydroxyl group and a carboxyl group, and a photosensitive resin having two or more thiol groups. Here, "photosensitive" means having an ethylenically unsaturated double bond.
(A) The alkali developable resin more preferably has a carboxyl group, and has a carboxyl group-containing photosensitive resin starting from an epoxy resin, a carboxyl group-containing photosensitive resin starting from a phenol compound, and a copolymerized structure. Carboxyl group-containing photosensitive resins and photosensitive carboxyl group-containing resins having a urethane structure are more preferable. The ethylenically unsaturated double bond is preferably derived from (meth) acrylic acid or a (meth) acrylic acid derivative.
Specific examples of (A) the alkali-developable resin include, but are not limited to, compounds (which may be oligomers or polymers) listed below as (1) to (10).

(1) To a carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene. Carboxyl group having a copolymerized structure obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups to a molecule such as glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, etc. Containing photosensitive resin. In addition, lower alkyl refers to an alkyl group having 1 to 5 carbon atoms.

(2-1) A carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diisocyanate, a carboxyl group-containing dialcohol compound, and a diol compound is further provided with one epoxy group and one or more (meth) ) A carboxyl group-containing photosensitive resin having a urethane structure obtained by adding a compound having an acryloyl group.
(2-2) having a urethane structure obtained by reacting a diisocyanate, a carboxyl group-containing dialcohol compound, a diol compound, and a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule. Carboxyl group-containing photosensitive resin.
(2-3) A urethane structure obtained by reacting a diisocyanate, a carboxyl group-containing dialcohol compound, a diol compound, and a compound having one isocyanate group and one or more (meth) acryloyl groups in a molecule. Having a carboxyl group-containing photosensitive resin.
Here, examples of the diisocyanate include an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, and an aromatic diisocyanate.
Examples of the carboxyl group-containing dialcohol compound include dimethylolpropionic acid and dimethylolbutanoic acid.
Examples of the diol compound include polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, compounds having a phenolic hydroxyl group and an alcoholic hydroxyl group, and the like. Can be
Examples of the compound having one hydroxyl group and one or more (meth) acryloyl groups in the molecule include hydroxyalkyl (meth) acrylate.
Examples of the compound having one isocyanate group and one or more (meth) acryloyl groups in the molecule include an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate.

(3-1) Carboxyl group-containing urethane structure by polyaddition reaction of diisocyanate, (meth) acrylate of bifunctional epoxy resin or its partial acid anhydride modified product, carboxyl group-containing dialcohol compound and diol compound Photosensitive resin.
(3-2) a carboxyl having a urethane structure obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups in the molecule to the carboxyl group-containing photosensitive resin of (3-1). Group-containing photosensitive resin.
(3-3) diisocyanate, (meth) acrylate of a bifunctional epoxy resin or a partial acid anhydride modified product thereof, a carboxyl group-containing dialcohol compound, a diol compound, and one hydroxyl group and one or more A carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting a compound having a (meth) acryloyl group.
(3-4) diisocyanate, (meth) acrylate of bifunctional epoxy resin or its partial acid anhydride modified product, carboxyl group-containing dialcohol compound, diol compound, one isocyanate group and one or more in the molecule A carboxyl group-containing photosensitive resin having a urethane structure obtained by reacting the compound with a compound having a (meth) acryloyl group.

(4) A polyfunctional epoxy resin is reacted with an unsaturated monocarboxylic acid such as (meth) acrylic acid, and a hydroxyl group present in a side chain is reacted with a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride. Carboxyl group-containing photosensitive resin to which substances are added.

(5) A carboxyl group obtained by reacting an unsaturated group-containing monocarboxylic acid with a polyfunctional epoxy resin obtained by further epoxidizing a hydroxyl group of a bifunctional epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the resulting hydroxyl group. Containing photosensitive resin.

(6) an epoxy compound having a plurality of epoxy groups in one molecule, a compound such as p-hydroxyphenethyl alcohol having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, A carboxylic acid is reacted with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid for the alcoholic hydroxyl group of the obtained reaction product. Carboxyl group-containing photosensitive resin obtained by the reaction.

(7) Glycidyl (meth) acrylate, α-methylglycidyl (meth) is added to a carboxyl group-containing polyester resin obtained by reacting a dicarboxylic acid with a polyfunctional oxetane resin and adding a dibasic acid anhydride to a generated primary hydroxyl group. A) a carboxyl group-containing photosensitive resin obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups in a molecule such as acrylate;

(8) A reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide is reacted with an unsaturated group-containing monocarboxylic acid to obtain a reaction product. Carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

(9) An unsaturated group-containing monocarboxylic acid is reacted with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride with a reaction product.

(10) A compound having one epoxy group and one or more (meth) acryloyl groups in the molecule as described above is added to the carboxyl group-containing photosensitive resin of (4) to (9). Carboxyl group-containing photosensitive resin.

  (A) The acid value of the alkali-developable resin is preferably in the range of 20 to 200 mgKOH / g, more preferably in the range of 40 to 150 mgKOH / g. (A) When the acid value of the alkali-developable resin is 20 mgKOH / g or more, the adhesion of the coating film is good, and when the photocurable resin composition is used, the alkali development becomes good. On the other hand, when the acid value is 200 mgKOH / g or less, the dissolution of the exposed portion by the developer can be suppressed, so that the line becomes thinner than necessary, and in some cases, the exposed portion and the unexposed portion dissolve and peel with the developer without distinction. And a resist pattern can be satisfactorily drawn.

  (A) As the alkali developable resin, the carboxyl group-containing photosensitive resins (4) to (10) are preferable, and the carboxyl group-containing photosensitive resins (8) and (9) are more preferable from the viewpoint of HAST resistance. .

The weight average molecular weight of the alkali developable resin (A) varies depending on the resin skeleton, but is preferably in the range of 1,500 to 50,000, more preferably 1,500 to 30,000. When the weight average molecular weight is 1,500 or more, tack-free performance is good, the moisture resistance of the coating film after exposure is good, film loss during development can be suppressed, and a decrease in resolution can be suppressed. On the other hand, when the weight average molecular weight is 50,000 or less, the developability is good and the storage stability is excellent.
(A) The double bond equivalent of the alkali developable resin is, for example, 500 to 3,500 eq. / G from the viewpoint of resolution. / G.

  (A) The alkali developable resin may be used alone or in combination of two or more. Further, as long as the effects of the present invention are not impaired, a conventionally known alkali developable resin having no ethylenically unsaturated double bond may be used in combination. (A) The compounding amount of the alkali-developable resin is preferably 5 to 50% by mass, more preferably 10 to 50% by mass in the whole composition. In the case of 5 to 50% by mass, the coating film strength is good, and the viscosity of the composition is moderate, and the coating property and the like can be improved.

（式中、Ｘは、水素原子、炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、フェニル基、フェニル基（炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、アミノ基、炭素数１〜８のアルキル基を持つアルキルアミノ基またはジアルキルアミノ基により置換されている）、ナフチル基（炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、アミノ基、炭素数１〜８のアルキル基を持つアルキルアミノ基またはジアルキルアミノ基により置換されている）を表し、Ｙ、Ｚはそれぞれ、水素原子、炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、ハロゲン基、フェニル基、フェニル基（炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、アミノ基、炭素数１〜８のアルキル基を持つアルキルアミノ基またはジアルキルアミノ基により置換されている）、ナフチル基（炭素数１〜１７のアルキル基、炭素数１〜８のアルコキシ基、アミノ基、炭素数１〜８のアルキル基を持つアルキルアミノ基またはジアルキルアミノ基により置換されている）、アンスリル基、ピリジル基、ベンゾフリル基、ベンゾチエニル基を表し、Ａｒは、結合か、炭素数１〜１０のアルキレン、ビニレン、フェニレン、ビフェニレン、ピリジレン、ナフチレン、チオフェン、アントリレン、チエニレン、フリレン、２，５−ピロール−ジイル、４，４’−スチルベン−ジイル、４，２’−スチレン−ジイルを表し、ｎは０か１の整数である。） [(B) Photopolymerization initiator generating radical and base]
The (B) photopolymerization initiator comprises a reaction between (A) an alkali developable resin having an ethylenically unsaturated double bond having poor photoreactivity and (A) an alkali developable resin having an ethylenically unsaturated double bond. Can efficiently proceed, and at the same time, can generate a base and serve as a catalyst for reacting (A) an alkali developable resin having an ethylenically unsaturated double bond with (C) a thermosetting component. .
In other words, since (B) a photopolymerization initiator is used, even if the composition does not contain a highly reactive (E) organic compound having an ethylenically unsaturated double bond, (A) ethylenically unsaturated The reaction between the alkali-developable resin having a double bond and (A) the alkali-developable resin having an ethylenically unsaturated double bond proceeds appropriately to form a cross-linked structure by light, so that the resin can be heated after development. A pattern as designed can be formed without causing pattern collapse (resin flow).
(B) Examples of the photopolymerization initiator include oxime ester-based photopolymerization initiators and α-aminoacetophenone-based photopolymerization initiators.
As the oxime ester-based photopolymerization initiator, as commercial products, CGI-325 and Irgacure OXE01 (1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyl) manufactured by BASF Japan Ltd. are available. Oxime)]), Irgacure OXE02 (ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (0-acetyloxime)), manufactured by ADEKA N-1919, NCI-831, TR-PBG-304 manufactured by Changzhou Strong Electronic New Materials Co., Ltd., TOE-04-A3 manufactured by Nippon Chemical Industry Co., Ltd., and the like.
In addition, an initiator having two oxime ester groups in a molecule can also be suitably used, and specific examples thereof include an oxime ester compound having a carbazole structure represented by the following general formula.

(Wherein X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms) A group, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group, a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, Y and Z are a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkyl group having 1 to 17 carbon atoms, and an alkyl group substituted with an alkylamino group having 1 to 8 carbon atoms or a dialkylamino group having 1 to 8 carbon atoms. To 8 alkoxy groups, halogen groups, phenyl groups, phenyl groups (alkyl groups having 1 to 17 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, amino groups, and alkyl groups having 1 to 8 carbon atoms) An amino group substituted with a mino group or a dialkylamino group, a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkyl group having an alkyl group having 1 to 8 carbon atoms) Or substituted with a dialkylamino group), an anthryl group, a pyridyl group, a benzofuryl group, a benzothienyl group, and Ar is a bond or an alkylene having 1 to 10 carbon atoms, vinylene, phenylene, biphenylene, pyridylene, naphthylene, Represents thiophene, anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4'-stilbene-diyl, 4,2'-styrene-diyl, and n is an integer of 0 or 1.)

  In particular, in the above general formula, X and Y are each a methyl group or an ethyl group, Z is a methyl group or a phenyl group, n is 0, and Ar is a bond, phenylene, naphthylene, thiophene or thienylene. It is preferred that

（式中、Ｒ^１は、炭素原子数１〜４のアルキル基、または、ニトロ基、ハロゲン原子もしくは炭素原子数１〜４のアルキル基で置換されていてもよいフェニル基を表す。
Ｒ^２は、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基、または、炭素原子数１〜４のアルキル基もしくはアルコキシ基で置換されていてもよいフェニル基を表す。
Ｒ^３は、酸素原子または硫黄原子で連結されていてもよく、フェニル基で置換されていてもよい炭素原子数１〜２０のアルキル基、炭素原子数１〜４のアルコキシ基で置換されていてもよいベンジル基を表す。
Ｒ^４は、ニトロ基、または、Ｘ−Ｃ（＝Ｏ）−で表されるアシル基を表す。Ｘは、炭素原子数１〜４のアルキル基で置換されていてもよいアリール基、チエニル基、モルホリノ基、チオフェニル基、または、下記式で示される構造を表す。）

Preferred carbazole oxime ester compounds include compounds represented by the following general formula.

(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms or a phenyl group which may be substituted with a nitro group, a halogen atom or an alkyl group having 1 to 4 carbon atoms.
R ² represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may be substituted with an alkyl group or an alkoxy group having 1 to 4 carbon atoms.
R ³ may be connected with an oxygen atom or a sulfur atom, and may be substituted with a phenyl group-substituted alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Represents a good benzyl group.
R ⁴ represents a nitro group or an acyl group represented by X—C (＝ O) —. X represents an aryl group which may be substituted with an alkyl group having 1 to 4 carbon atoms, a thienyl group, a morpholino group, a thiophenyl group, or a structure represented by the following formula. )

  In addition, JP-A-2004-359639, JP-A-2005-097141, JP-A-2005-220097, JP-A-2006-160634, JP-A-2008-094770, JP-T-2008-509967, Examples thereof include carbazole oxime ester compounds described in JP-T-2009-040762 and JP-A-2011-80036.

  As the α-aminoacetophenone-based photopolymerization initiator, specifically, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N , N-dimethylaminoacetophenone and the like. Commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

  As the photopolymerization initiator (B), one type can be used alone, or two or more types can be used in combination. The blending amount of the photopolymerization initiator (B) is preferably 0.01 to 30 parts by mass, and more preferably 0.25 to 15 parts by mass, based on 100 parts by mass of the alkali developable resin (A). More preferred. By setting the content to 0.01 to 30 parts by mass, resolution and PCT resistance are improved, photocurability is improved, adhesion is improved, and further, chemical resistance such as electroless gold plating resistance is also improved. A cured film can be obtained.

  The curable resin composition of the present invention may contain other photopolymerization initiators other than the photopolymerization initiator (B) as long as the effects of the invention are not impaired. As the other photopolymerization initiator, one or more photopolymerization initiators selected from the group consisting of an alkylphenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and a titanocene-based photopolymerization initiator are preferably used. Can be used. Commercially available alkylphenone-based photopolymerization initiators include α-hydroxyalkylphenone types such as Irgacure 184, Darocure 1173, Irgacure 2959, and Irgacure 127 manufactured by BASF Japan.

  As the acylphosphine oxide-based photopolymerization initiator, specifically, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxy) Benzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Commercially available products include Lucirin TPO manufactured by BASF, and Irgacure 819 manufactured by BASF Japan.

  The curable resin composition may use a photoinitiator and a sensitizer in addition to the photopolymerization initiator. Examples of the photopolymerization initiator, photoinitiator and sensitizer that can be suitably used in the curable resin composition include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, and tertiary amines. And xanthone compounds.

  Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

  Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone.

  Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, and the like.

  Specific examples of the thioxanthone compound include, for example, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

  Specific examples of the benzophenone compound include, for example, benzophenone, 4-benzoyldiphenylsulfide, 4-benzoyl-4′-methyldiphenylsulfide, 4-benzoyl-4′-ethyldiphenylsulfide, 4-benzoyl-4′-propyldiphenyl Sulfide and the like.

  Specific examples of the tertiary amine compound include, for example, an ethanolamine compound and a compound having a dialkylaminobenzene structure. For example, commercially available products include 4,4′-dimethylaminobenzophenone (Nissocure MABP manufactured by Nippon Soda Co., Ltd.), Dialkylaminobenzophenones such as 4'-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.), 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin) and the like Dialkylamino group-containing coumarin compound, ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku), ethyl 2-dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), 4-dimethyla (N-butoxy) ethyl benzoate (Quantacure BEA manufactured by International Bio-Synthetics), isoamyl ethyl p-dimethylaminobenzoate (Kayacure DMBI manufactured by Nippon Kayaku), 2-ethylhexyl 4-dimethylaminobenzoate (Esolol 507 manufactured by Van Dyk), 4,4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.) and the like.

  Of these, thioxanthone compounds and tertiary amine compounds are preferred. In particular, it is preferable that a thioxanthone compound is contained from the viewpoint of deep curing. Among them, it is preferable to include a thioxanthone compound such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  Further, as the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound, a dialkylamino group-containing coumarin compound having a maximum absorption wavelength in the range of 350 to 450 nm, and ketocoumarins are particularly preferable. .

  As the dialkylaminobenzophenone compound, 4,4'-diethylaminobenzophenone is preferable because of its low toxicity. Dialkylamino group-containing coumarin compounds have a maximum absorption wavelength in the ultraviolet region of 350 to 410 nm, so they are less colored and use not only colorless and transparent photosensitive compositions but also colored pigments, and coloring that reflects the color of the colored pigment itself. It becomes possible to provide a solder resist. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferred because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

  These photopolymerization initiators, photoinitiation assistants and sensitizers can be used alone or as a mixture of two or more. The total amount of the photopolymerization initiator, photoinitiator and sensitizer is preferably 35 parts by mass or less based on 100 parts by mass of the alkali developable resin (A). When the amount is 35 parts by mass or less, it is possible to suppress a decrease in deep-side curability due to the light absorption.

[(C) thermosetting component]
The curable resin composition of the present invention contains (C) a thermosetting component. It can be expected that the heat resistance will be improved by adding a thermosetting component. As the thermosetting component (C), one type can be used alone, or two or more types can be used in combination. As the thermosetting component (C), any known component can be used. For example, known thermosetting components such as melamine resin, benzoguanamine resin, melamine derivative, amino resin such as benzoguanamine derivative, isocyanate compound, blocked isocyanate compound, cyclocarbonate compound, epoxy compound, oxetane compound, episulfide resin, bismaleimide, and carbodiimide resin. Can be used. Particularly preferred are thermosetting components having a plurality of cyclic ether groups or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule.

  The thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is a compound having a plurality of 3, 4 or 5-membered cyclic (thio) ether groups in the molecule. A compound having an epoxy group, ie, a polyfunctional epoxy compound, a compound having a plurality of oxetanyl groups in a molecule, ie, a polyfunctional oxetane compound, a compound having a plurality of thioether groups in a molecule, ie, an episulfide resin.

  Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A epoxy resin; hydroquinone epoxy resin; bisphenol epoxy resin; thioether epoxy resin; brominated epoxy resin; novolak epoxy resin; biphenol novolak epoxy resin; Type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydantoin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixylenol type or biphenol type epoxy resin or a mixture thereof; Bisphenol S epoxy resin; bisphenol A novolak epoxy resin; tetraphenylolethane epoxy resin; heterocyclic epoxy resin; diglycidyl Tartrate resin; Tetraglycidylxylenoylethane resin; Naphthalene group-containing epoxy resin; Epoxy resin having a dicyclopentadiene skeleton; Glycidyl methacrylate copolymer epoxy resin; Copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; A polybutadiene rubber derivative; a CTBN-modified epoxy resin; and the like, but not limited thereto. These epoxy resins can be used alone or in combination of two or more. Among these, a novolak-type epoxy resin, a bisphenol-type epoxy resin, a bixylenol-type epoxy resin, a biphenol-type epoxy resin, a biphenol novolak-type epoxy resin, a naphthalene-type epoxy resin, and a mixture thereof are particularly preferable.

  Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, and 1,4-bis [(3- Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3- Oxetane alcohol and novolak resin, in addition to polyfunctional oxetanes such as (oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and their oligomers and copolymers , Poly (p-hydroxystyrene), cardo-type bis Phenol ethers, calixarenes, calix resorcin arenes or etherified products such as the resin having a hydroxyl group such as silsesquioxane and the like. Other examples include a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate.

  Examples of the compound having a plurality of cyclic thioether groups in the molecule include a bisphenol A-type episulfide resin. In addition, an episulfide resin in which an oxygen atom of an epoxy group of a novolak type epoxy resin is replaced with a sulfur atom using a similar synthesis method can also be used. The compounding amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is such that the cyclic (thio) ether group is (A) an alkali-soluble resin such as a carboxyl group or a phenolic hydroxyl group of an alkali-developable resin. It is preferably 0.6 to 2.5 equivalents, more preferably 0.8 to 2.0 equivalents, per equivalent of the group.

  Examples of the amino resin such as a melamine derivative and a benzoguanamine derivative include a methylol melamine compound, a methylol benzoguanamine compound, a methylol glycoluril compound, and a methylol urea compound.

  A polyisocyanate compound can be blended as the isocyanate compound. Examples of the polyisocyanate compound include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate; Alicyclic polyisocyanates such as heptane triisocyanate; and adducts of the above-mentioned isocyanate compounds; Yuretto body and isocyanurate products thereof.

  As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent can be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the above-described polyisocyanate compounds. Examples of the isocyanate blocking agent include a phenol blocking agent; a lactam blocking agent; an active methylene blocking agent; an alcohol blocking agent; an oxime blocking agent; a mercaptan blocking agent; an acid amide blocking agent; Amine blocking agents; imidazole blocking agents; imine blocking agents and the like.

  The amount of the thermosetting component (C) is preferably from 1 to 100 parts by mass based on 100 parts by mass of the alkali developable resin (A). More preferably, it is 2 to 70 parts by mass.

[(D) silica]
The curable resin composition of the present invention contains (D) silica as a filler. (D) Silica is used for suppressing curing shrinkage of a cured product of the curable resin composition and improving properties such as adhesion and hardness. Examples of the silica include fused silica, spherical silica, amorphous silica, and crystalline silica.

(D) The silica is preferably surface-treated silica, more preferably silica surface-treated with a coupling agent.
As the coupling agent, silane-based, titanate-based, aluminate-based, and zircoaluminate-based coupling agents can be used. Among them, a silane coupling agent is preferable. Examples of such a silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-amino Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy Cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and these can be used alone or in combination. It is preferable that these silane coupling agents are previously fixed to the surface of silica by adsorption or reaction. In the present invention, the coupling agent applied to the silica is not included in (E) the organic compound having an ethylenically unsaturated double bond.
Further, a filler other than (D) silica may be added as long as the effect of the present invention is not impaired. Fillers other than silica include, for example, inorganic fillers such as barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, titanium oxide, aluminum hydroxide, silicon nitride, and aluminum nitride. Can be Moreover, you may mix | blend an organic filler as a filler. As the filler, one type can be used alone, or two or more types can be used in combination.

(D) The silica preferably has an average particle size of 5 μm or less. (D) The compounding amount of silica is preferably 20 to 90% by mass based on the total solid content of the curable resin composition. The amount of the silica (D) is from 30 to 80 based on the total solid content of the curable resin composition in consideration of the stability of the pattern shape, that is, the balance between the resolution and the reduction of the linear expansion coefficient. %, More preferably from 40 to 80% by mass, even more preferably from 50 to 70% by mass.
(D) When the content of silica is 30 to 80% by mass on the basis of the total solid content, the coatability of the composition is good, and a cured product having excellent properties as a solder resist for IC package is obtained, which is preferable. .

[(E) Organic compound having ethylenically unsaturated double bond]
The curable resin composition of the present invention does not substantially contain (E) an organic compound having an ethylenically unsaturated double bond in addition to (A) an alkali developable resin having an ethylenically unsaturated double bond. (E) Examples of the organic compound having an ethylenically unsaturated double bond include acrylate compounds and the like, which are blended as a photoreactive monomer in a conventional curable resin composition.

  Here, "substantially does not contain" means that it is not positively compounded as a constituent, and it is not excluded that a small amount is contained as long as the effects of the present invention are not impaired. For example, the amount is 5 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 1 part by mass or less, per 100 parts by mass of the alkali developable resin (A).

(Colorant)
The curable resin composition of the present invention may contain a coloring agent. As the coloring agent, commonly used coloring agents such as red, blue, green, yellow, white, and black can be used, and any of pigments, dyes, and pigments may be used. Specifically, those having a color index (CI; issued by The Society of Dyers and Colorists) can be cited. However, it is preferable that the coloring agent does not contain a halogen from the viewpoint of reducing the environmental load and affecting the human body.

  Examples of the red colorant include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. Examples of blue colorants include metal-substituted or unsubstituted phthalocyanine-based and anthraquinone-based pigments, and pigment-based compounds include compounds classified as Pigment. Green colorants include phthalocyanine-based, anthraquinone-based, and perylene-based, similarly substituted or unsubstituted metals. Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone. Examples of the white colorant include rutile-type and anatase-type titanium oxide. Black colorants include titanium black, carbon black, graphite, iron oxide, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, and aniline. Pigment, molybdenum sulfide, bismuth sulfide and the like can be mentioned. In addition, a coloring agent such as purple, orange, or brown may be added for the purpose of adjusting the color tone.

  The coloring agents can be used alone or in combination of two or more. The amount of the colorant is not particularly limited, but is preferably 10 parts by mass or less based on 100 parts by mass of the alkali developable resin (A). More preferably, it is 0.1 to 5 parts by mass.

(Organic solvent)
An organic solvent is used in the curable resin composition of the present invention for the purpose of (A) synthesizing an alkali-developable resin, preparing the composition, or adjusting the viscosity for applying to a substrate or a carrier film. Can be. Examples of the organic solvent include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate , Propylene glycol ethyl ether acetate, propylene glycol butyl ether Esters such as acetate; alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha, etc. is there. Such organic solvents can be used alone or in combination of two or more.

(Other optional components)
The curable resin composition of the present invention further comprises a cyanate compound, an elastomer, a mercapto compound, a thermosetting catalyst, a urethanization catalyst, a thixolating agent, an adhesion promoter, a block copolymer, a chain transfer agent, if necessary. Polymerization inhibitors, copper damage inhibitors, antioxidants, rust inhibitors, ultraviolet absorbers, thickening agents such as finely divided silica, organic bentonite, montmorillonite, silicone-based, fluorine-based, polymer-based antifoaming agents and / or Alternatively, components such as a leveling agent, a silane coupling agent such as an imidazole type, a thiazole type, and a triazole type, and a flame retardant such as a phosphorus compound such as a phosphinate, a phosphate ester derivative, and a phosphazene compound can be added. As these, those known in the field of electronic materials can be used.

  The curable resin composition of the present invention is useful for forming a pattern layer as a permanent coating of a printed wiring board such as a solder resist, a coverlay, and an interlayer insulating layer, and is particularly useful for forming a solder resist. Further, since the curable resin composition of the present invention has excellent resolution, it can be suitably used for forming a pattern layer of an IC package which requires formation of a fine pattern.

  The curable resin composition of the present invention may be in the form of a dry film including a carrier film (support) and a resin layer formed of the curable resin composition formed on the carrier film. In forming a dry film, the curable resin composition of the present invention is diluted with the above-mentioned organic solvent to adjust to an appropriate viscosity, and a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater , A gravure coater, a spray coater, or the like, is applied to a uniform thickness on a carrier film, and is usually dried at a temperature of 50 to 130 ° C. for 1 to 30 minutes to obtain a film. The thickness of the applied film is not particularly limited, but is generally selected appropriately in the range of 1 to 150 μm, preferably 10 to 60 μm in terms of the thickness after drying.

  As the carrier film, a plastic film is used, and it is preferable to use a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, and a polystyrene film. The thickness of the carrier film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 μm.

  After the curable resin composition of the present invention is formed on a carrier film, a peelable cover film may be further laminated on the surface of the film for the purpose of preventing dust from adhering to the surface of the film. preferable. As the peelable cover film, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper and the like can be used. It is only necessary that the adhesive strength between the film and the cover film is smaller.

[Pattern forming method]
The pattern forming method in which the curable resin composition of the present invention can be preferably used includes a step (A) of forming a resin layer composed of the curable resin composition on a substrate, and a negative pattern light irradiation. (B) a step of activating the photopolymerization initiator contained in the curable resin composition to cure the light-irradiated part (B), and a step of forming a negative-type pattern layer by removing the unirradiated part by development ( C).
The light irradiation part is cured by generating a base in the light irradiation part of the curable resin composition by pattern light irradiation. Thereafter, by developing with an organic solvent or an aqueous alkali solution, the unirradiated portion is removed, and a negative pattern layer is formed.
Here, in the present invention, it is preferable to include a step (B1) of heating the resin layer after the step (B). This makes it possible to sufficiently cure the resin layer and obtain a pattern layer having further excellent curing properties.

[Step (A)]
Step (A) is a step of forming a resin layer made of a curable resin composition on a substrate. The method of forming the resin layer may be a method of applying and drying a liquid curable resin composition on a substrate, or a method of laminating a dry film of the curable resin composition on a substrate. it can.

As a method for applying the curable resin composition to the substrate, a known method such as a blade coater, a lip coater, a comma coater, or a film coater can be appropriately used. The drying method is a method using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, etc. equipped with a heat source of a heating method using steam, a method in which hot air in the dryer is brought into countercurrent contact, and a method supported by a nozzle. A known method such as a method of spraying on a body can be applied.
As the base material, in addition to a printed circuit board or a flexible printed circuit board on which a circuit is formed in advance, paper-phenol resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven cloth-epoxy resin, Glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, copper-clad laminates of all grades (FR-4 etc.) using composite materials such as fluorine, polyethylene, polyphenylene ether, polyphenylene oxide, cyanate, polyimide film, A PET film, a glass substrate, a ceramic substrate, a wafer substrate, or the like can be used.

[Step (B)]
The step (B) is a step of irradiating light in a negative pattern to activate the (B) photopolymerization initiator contained in the curable resin composition to cure the light-irradiated portion. In the step (B), it is considered that a base and a radical are generated in the light irradiation section, the generated base destabilizes the (B) photopolymerization initiator, and further generates a base. As a result of the base multiplying chemically, the base can be sufficiently cured to the deep part of the light irradiation part.
As a light irradiator used for light irradiation, for example, a direct drawing device capable of irradiating laser light, lamp light, or LED light can be used. A negative mask can be used as the pattern-shaped light irradiation mask.

It is preferable to use laser light or scattered light having a maximum wavelength in the range of 350 to 410 nm as the active energy ray. By setting the maximum wavelength in this range, the thermal reactivity of the curable resin composition can be efficiently improved. Either a gas laser or a solid-state laser may be used as long as the laser light in this range is used. The light irradiation amount varies depending on the film thickness and the like, but can be generally in the range of ^{20 to} 1000 mJ / cm ² , preferably 20 to 300 mJ / cm ² .

  As the direct drawing apparatus, for example, those manufactured by Nippon Orbotech Co., Ltd., Pentax Co., etc. can be used, and any apparatus that oscillates laser light having a maximum wavelength of 350 to 410 nm may be used. .

[Step (B1)]
In the step (B1), the light irradiation part is cured by heating. In the step (B1), the base can be cured to a deep part by the base generated in the step (B).
The heating temperature is preferably a temperature at which the light-irradiated portion of the curable resin composition is thermally cured, but the unirradiated portion is not thermally cured.
For example, in the step (B1), the temperature is lower than the exothermic start temperature or exothermic peak temperature of the unirradiated curable resin composition, and is higher than the exothermic start temperature or exothermic peak temperature of the light-irradiated curable resin composition. It is preferred to heat with. By heating as described above, only the light irradiation part can be selectively cured.
Here, the heating temperature is, for example, 70 to 140 ° C. By setting the heating temperature to 70 ° C. or higher, the light irradiation part can be sufficiently cured. On the other hand, by setting the heating temperature to 140 ° C. or lower, only the light irradiation part can be selectively cured. The heating time is, for example, 5 to 100 minutes. The heating method is the same as the above-mentioned drying method.
In the unirradiated portion, no base is generated from the photopolymerization initiator, so that thermal curing is suppressed.

[Step (C)]
Step (C) is a step of forming a negative pattern layer by removing unirradiated portions by development. As a developing method, a known method such as a dipping method, a shower method, a spray method, and a brush method can be used. Examples of the developing solution include amines such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, and ethanolamine, and an aqueous solution of tetramethylammonium hydroxide (TMAH). ) Or a mixture thereof.

[Step (D)]
It is preferable that the pattern forming method further includes an ultraviolet irradiation step (D) after the step (C). By further performing ultraviolet irradiation after the step (C), it is possible to activate the photopolymerization initiator (B) remaining without being activated at the time of light irradiation. In the ultraviolet irradiation step (D) after the step (C), the ultraviolet wavelength and the light irradiation amount (exposure amount) may be the same as or different from the step (B). A suitable light irradiation amount (exposure amount) is 150 to 2000 mJ / cm ² .

[Step (E)]
It is preferable that the pattern formation method further includes a thermosetting (post-curing) step (E) after the step (C).
When both the step (D) and the step (E) are performed after the step (C), the step (E) is preferably performed after the step (D).
In the step (E), the pattern layer is sufficiently thermoset with the base generated from the photopolymerization initiator (B) in the step (B) or the steps (B) and (D). At the time of the step (E), since the unirradiated portion has already been removed, the step (E) can be performed at a temperature equal to or higher than the curing reaction starting temperature of the unirradiated curable resin composition. Thereby, the pattern layer can be sufficiently thermoset. The heating temperature is, for example, 160 ° C. or higher. After the step (E), an ultraviolet irradiation step may be further included.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following, “parts” and “%” are all based on mass unless otherwise specified.

(Synthesis example 1: Synthesis of alkali developable resin A-1 having an ethylenically unsaturated double bond)
A flask equipped with a condenser and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or lower, and added 228 parts of a 25% aqueous sodium hydroxide solution. Reaction was performed at 10 ° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40 ° C., and neutralized to pH 4 with a 37.5% phosphoric acid aqueous solution while maintaining the temperature at 40 ° C. or lower. Thereafter, the mixture was allowed to stand, and the aqueous layer was separated. After the separation, 300 parts of methyl isobutyl ketone was added and uniformly dissolved, followed by washing three times with 500 parts of distilled water, and removing water, solvent and the like under a reduced pressure at a temperature of 50 ° C. or lower. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.
A part of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature, and the solid content was 55.2%.
In a flask equipped with a condenser and a stirrer, 500 parts of a methanol solution of the obtained polymethylol compound and 440 parts of 2,6-xylenol were charged and uniformly dissolved at 50 ° C. After uniform dissolution, methanol was removed under reduced pressure at a temperature of 50 ° C. or less. Thereafter, 8 parts of oxalic acid was added, and the mixture was reacted at 100 ° C. for 10 hours. After the completion of the reaction, the distillate was removed at 180 ° C. under a reduced pressure of 50 mmHg to obtain 550 parts of novolak resin A.
In an autoclave equipped with a thermometer, a nitrogen introduction device, an alkylene oxide introduction device, and a stirring device, 130 parts of novolak resin A, 2.6 parts of a 50% aqueous sodium hydroxide solution, and toluene / methyl isobutyl ketone (mass ratio = 2/1) 100 parts were charged, the inside of the system was replaced with nitrogen while stirring, then the temperature was increased by heating, and 60 parts of propylene oxide was gradually introduced at 150 ° C. and 8 kg / cm ² to cause a reaction. The reaction was continued for about 4 hours until the gauge pressure became 0.0 kg / cm ^2, and then cooled to room temperature. To this reaction solution, 3.3 parts of a 36% hydrochloric acid aqueous solution was added and mixed to neutralize sodium hydroxide. The neutralized reaction product was diluted with toluene, washed three times with water, and the solvent was removed with an evaporator to give a hydroxyl value of 189 g / eq. Of novolak resin A was obtained. This was one in which propylene oxide was added on average to 1 mole per equivalent of phenolic hydroxyl group.
189 parts of propylene oxide adduct of the obtained novolak resin A, 36 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether, and 140 parts of toluene were stirred with a stirrer, a thermometer, and an air blowing tube. The mixture was stirred while blowing in air, heated to 115 ° C., reacted for another 4 hours while distilling off water produced by the reaction as an azeotrope with toluene, and then allowed to reach room temperature. Cool. The obtained reaction solution was washed with 5% aqueous NaCl solution, and toluene was removed by distillation under reduced pressure. Then, diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a nonvolatile content of 67%.
Next, 322 parts of the obtained acrylate resin solution, 0.1 part of hydroquinone monomethyl ether and 0.3 part of triphenylphosphine were charged into a four-necked flask equipped with a stirrer and a reflux condenser. , 60 parts of tetrahydrophthalic anhydride was added, and the mixture was reacted for 4 hours. After cooling, it was taken out. The carboxyl group-containing photosensitive resin thus obtained had a nonvolatile content of 70% and a solid content acid value of 81 mgKOH / g. Hereinafter, this solution of the carboxyl group-containing photosensitive resin is referred to as a resin solution A-1.

(Synthesis Example 2: Synthesis of alkaline developable resin A-2 having an ethylenically unsaturated double bond)
Orthocresol novolak type epoxy resin [manufactured by DIC, EPICLON N-695, softening point 95 ° C, epoxy equivalent 214, average functional group number 7.6] 1070 g, diethylene glycol monoethyl ether acetate 600 g, acrylic acid 360 g, and hydroquinone 1.5 g And heated and stirred at 100 ° C. to dissolve uniformly. Next, 4.3 g of triphenylphosphine was charged, heated at 110 ° C., reacted for 2 hours, and then heated to 120 ° C., and further reacted for 12 hours. To the obtained reaction solution, 415 g of an aromatic hydrocarbon (Solvesso 150) and 456.0 g of tetrahydrophthalic anhydride were charged and reacted at 110 ° C. for 4 hours. After cooling, the solid content acid value was 89 mg KOH / g and the solid content was 70 % Resin solution was obtained. This is called resin solution A-2.

(Measurement of double bond equivalent)
After reacting morpholine with the alkali developable resins A-1 and A-2 having an ethylenically unsaturated double bond obtained above, acetic anhydride was added to react with unreacted morpholine. The double bond equivalent was calculated by titrating the reactant of the alkali developable resin having a double bond with morpholine with perchloric acid. The double bond equivalent was 1255 eq. For A-1 in terms of 100% solid content. / G, 979 eq. / G.

(Examples 1 to 18 and Comparative Examples 1 to 7)
The components were mixed in the proportions (parts by mass) shown in Tables 1 to 4 together with the various components shown in Tables 1 to 4 below, preliminarily mixed with a stirrer, and kneaded with a three-roll mill to prepare a curable resin composition. .

＊１：オキシムエステル系光重合開始剤、ＢＡＳＦジャパン社製
＊２：オキシムエステル系光重合開始剤、常州強力電子新材料有限公司社製
＊３：オキシムエステル系光重合開始剤、日本化学工業所社製
＊４〜＊６：α−アミノアセトフェノン系光重合開始剤、ＢＡＳＦジャパン社製
＊７：アシルフォスフィンオキサイド系光重合開始剤、ＢＡＳＦジャパン社製
＊８：ノボラック型エポキシ樹脂、ダウ・ケミカル社製
＊９：ビフェニル型エポキシ樹脂、三菱化学社製
＊１０：ナフトール変性エポキシ樹脂エポキシ樹脂、日本化薬社製
＊１１：フェノールアラルキル型エポキシ樹脂、日本化薬社製
＊１２、１３：ＣＩＫナノテック社製
＊１４：ジペンタエリスリトールペンタアクリレート
＊１５：トリシクロデカンジメタノールジアクリレート

* 1: Oxime ester photopolymerization initiator, manufactured by BASF Japan * 2: Oxime ester photopolymerization initiator, manufactured by Changzhou Strong Electronic New Materials Co., Ltd. * 3: Oxime ester photopolymerization initiator, Nippon Chemical Industry Co., Ltd. * 4 to * 6: α-aminoacetophenone-based photopolymerization initiator, manufactured by BASF Japan * 7: Acylphosphine oxide-based photopolymerization initiator, manufactured by BASF Japan * 8: Novolac epoxy resin, Dow Chemical * 9: Biphenyl type epoxy resin, manufactured by Mitsubishi Chemical Corporation * 10: Naphthol-modified epoxy resin epoxy resin, manufactured by Nippon Kayaku * 11: Phenol aralkyl type epoxy resin, manufactured by Nippon Kayaku * 12, 13: CIK Nanotech * 14: dipentaerythritol pentaacrylate * 15: tricyclodecane dimethanol diacrylate

  The curable resin compositions of Examples and Comparative Examples shown in Tables 1 to 4 were evaluated by the following methods. The evaluation results are shown in Tables 5 to 8.

[Examples 1 to 18 and Comparative Examples 1 to 7]
(Production of dry film)
A dry film having a resin layer was produced using each of the curable resin compositions of Examples 1 to 18 and Comparative Examples 1 to 7. The dry film was prepared by using a polyester film having a thickness of 38 μm as a carrier film, applying the curable resin composition on the carrier film using an applicator, and drying the coating at 80 ° C. for 10 minutes.

(Optimal exposure)
A single-sided printed circuit board on which a circuit having a copper thickness of 15 μm was formed was prepared, and pre-processed using CZ8100 manufactured by MEC. The resin film was formed on the substrate by bonding the dry film according to each of the examples and the comparative examples to the substrate using a vacuum laminator so that the resin layer was in contact with the substrate. This substrate was exposed through a step tablet (Kodak No. 2) using an exposure apparatus equipped with a high-pressure mercury short arc lamp, and developed (30 ° C., 0.2 MPa, 1% by mass Na ₂ CO ₃ aqueous solution) for 60 seconds. When the pattern of the step tablet remaining after performing the above was three steps, it was determined as the optimum exposure amount.

(Characteristic test)
A single-sided printed wiring board on which a circuit having a copper thickness of 15 μm was formed was prepared, and pre-processed using CZ8100 manufactured by MEC. The resin film having a layer structure was formed on the substrate by bonding the dry film according to each of the examples and the comparative examples to the substrate using a vacuum laminator so that the resin layer was in contact with the substrate. After exposing the solder resist pattern to the substrate at an optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury short arc lamp, the carrier film was peeled off, and a spray pressure of 0% with a 1% by mass aqueous sodium carbonate solution at 30 ° C. Development was performed for 60 seconds under the condition of 0.2 MPa to obtain a solder resist pattern. The substrate was irradiated with ultraviolet rays in a UV conveyor furnace under the conditions of an integrated exposure amount of 1000 mJ / cm ² , and then cured by heating at 160 ° C. for 60 minutes. The characteristics of the obtained printed wiring board (evaluation substrate) were evaluated as follows.

<Resolution>
The pattern opening shape of the evaluation substrate was observed and evaluated. The criteria are as follows. The design value of the opening diameter was 80 μm.
◎: The opening diameter is less than ± 5% of the set opening diameter and the ratio of the opening diameter of the opening upper part to the bottom part is more than 0.95 and less than 1.05. The ratio of the opening diameter at the bottom is within 0.90 to 0.95 or within 1.05 to 1.10. Δ: The opening diameter exceeds ± 10% of the set opening diameter or the ratio of the opening diameter at the top and bottom of the opening is 0. X: Exceeding the range of 9.1 to 1.10. ×: The opening diameter exceeds ± 10% of the set opening diameter, and the ratio of the opening diameter at the top and bottom of the opening exceeds 0.9 to 1.10.

<PCT resistance>
The pattern of the cured product was subjected to electroless gold plating to obtain an evaluation substrate. This evaluation substrate was treated for 300 hours under the conditions of 121 ° C., saturation, and 0.2 MPa using a PCT apparatus (HAST SYSTEM TPC-412MD manufactured by Espec Corporation), and the PCT resistance was evaluated based on the state of the pattern.
The criteria are as follows.
◎: No swelling, peeling, discoloration ○: No swelling, peeling, discoloration △: Slight swelling, slight peeling X: Swelling, peeling often observed

<Linear expansion coefficient (CTE)>
The dry film prepared above was laminated on the glossy side (copper foil) of GTS-MP foil (made by Furukawa Circuit Foil) to form a resin layer on the copper foil. Next, the resin layer was irradiated with ultraviolet rays in a UV conveyor furnace under the conditions of an integrated exposure amount of 1000 mJ / cm ² , and then heated at 160 ° C. for 60 minutes to cure the resin layer to obtain a cured film. Thereafter, after the cured film was peeled off from the copper foil, a sample was cut out to a measurement size (3 mm × 10 mm size) and supplied to TMA6100 manufactured by Seiko Instruments Inc. In the TMA measurement, the test weight was 5 g, the sample was heated from room temperature at a heating rate of 10 ° C./min, and measured continuously twice. The intersection of two tangents having different linear expansion coefficients at the second time was defined as the glass transition temperature (Tg), and evaluated as the linear expansion coefficient (CTE (α1)) in a region equal to or lower than Tg. The criteria are as follows.
◎: CTE at Tg temperature or lower is 20 ppm or less ：: CTE at Tg temperature or lower is higher than 20 ppm or 50 ppm △: CTE at Tg temperature or lower is higher than 50 ppm or 80 ppm or lower X: CTE at Tg temperature or lower is higher than 80 ppm

From the results shown in the above Tables 5 to 8, it can be seen that (E) an ethylenically unsaturated double bond comprising an alkali developable resin having an ethylenically unsaturated double bond and (B) a photopolymerization initiator which generates a radical and a base. It was found that the curable resin compositions of Examples 1 to 18 containing no organic compound having a saturated double bond had excellent resolution and excellent PCT resistance of the cured product. In addition, it was found that when the compounding amount of (D) silica exceeds 30% by mass, the coefficient of linear expansion can be reduced.
On the other hand, in the curable resin compositions of Comparative Examples 1 to 7 containing (E) the organic compound having an ethylenically unsaturated double bond, the resolution and the PCT resistance of the cured product are insufficient. I understood.

Claims (6)

(A) an alkali developable resin having an ethylenically unsaturated double bond,
(B) a photopolymerization initiator that generates a radical and a base,
(C) a thermosetting component, and
(D) a curable resin composition containing silica,
(D) the amount of silica is 30 to 80% by mass based on the solid content of the total amount of the composition;
It is for forming a solder resist characterized in that it does not substantially contain (E) an organic compound having an ethylenically unsaturated double bond other than the (A) alkali developable resin having an ethylenically unsaturated double bond. An alkali developing type curable resin composition. (A) an alkali developable resin having an ethylenically unsaturated double bond,
(B) a photopolymerization initiator that generates a radical and a base,
(C) a thermosetting component, and
(D) a curable resin composition containing silica,
(D) the silica is surface-treated,
It is for forming a solder resist characterized in that it does not substantially contain (E) an organic compound having an ethylenically unsaturated double bond other than the (A) alkali developable resin having an ethylenically unsaturated double bond. An alkali developing type curable resin composition. Wherein (C) The curable resin composition according to claim 1 or 2 thermosetting component is an epoxy compound. Dry film characterized by having a resin layer obtained from the curable resin composition according to any one of claims 1-3. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 3 or the resin layer of the dry film according to claim 4 . A printed wiring board comprising the cured product according to claim 5 .