JP2020047654A - Curable resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

To provide a photosensitive curable resin composition and the like that has excellent resolution, in which cracks are less likely to be generated in a via hole opening after surface roughening treatment, and that is effective for forming an interlayer insulation layer with excellent adhesion to circuit conductors and insulation reliability between circuits.SOLUTION: A photosensitive curable resin composition and the like includes (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting compound, (D-1) an inorganic filler having an average particle size of 0.5 to 6 μm decomposed or dissolved by a roughening agent, and (D-2) a spherical inorganic filler that is not decomposed or dissolved by the roughening agent.SELECTED DRAWING: None

Description

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

As a method of manufacturing a printed wiring board, an interlayer insulating layer made of a thermosetting resin composition is formed on a circuit-formed substrate, and a via hole opening is provided in the interlayer insulating layer using a carbon dioxide gas laser or the like, and further subjected to plating. A method of forming a conductor circuit including a via hole by using a conventional method is widely known.
In such a method for manufacturing a printed wiring board, with the recent increase in the functionality and miniaturization of electronic devices, the density of conductive circuits has also increased, and it is necessary to form smaller-diameter via hole openings in the interlayer insulating layer. was there. However, in the conventional carbon dioxide laser processing, it is difficult to form an opening having a diameter of 40 μm or less, while UV laser processing in which a smaller diameter opening can be formed is also conceivable, but the processing time is long and there is a problem in productivity. .

  On the other hand, conventionally, there has been proposed a method in which a photolithography technique using a photosensitive curable resin composition is applied to forming a via hole opening in an interlayer insulating layer (for example, see Patent Documents 1 and 2).

  On the other hand, in a method for manufacturing a printed wiring board, a conductor circuit formed on an interlayer insulating layer is required to have excellent adhesion to the interlayer insulating layer, that is, so-called peel strength. Therefore, after roughening the surface of the interlayer insulating layer and the side surface of the opening for the via hole with a roughening agent such as sodium hydroxide, potassium permanganate, and sulfuric acid, the electroless copper plating process and the electrolytic copper plating process are performed. A method of forming a conductor circuit by sequentially performing a plating process is widely adopted (for example, see Patent Document 2).

  However, such a method of forming a conductor circuit has a problem that the contact area between the interlayer insulating layer and the circuit conductor increases due to the surface roughening treatment, thereby causing transmission loss and deterioration of insulation.

  In particular, in the method for forming a conductive circuit and the method for manufacturing a printed wiring board described in Patent Document 2 utilizing the photolithography technique described above, the surface and side surfaces of the via hole opening (via portion) are subjected to surface roughening treatment. The inventors have noticed a new problem of cracking. When such cracks occur, insulation reliability between adjacent via holes cannot be obtained, and the contact area between the circuit conductor and the interlayer insulating layer increases, resulting in a problem that transmission loss increases. It should be noted that such a crack after the surface roughening treatment is a problem that does not occur in the interlayer insulating layer formed using the thermosetting resin composition.

  On the other hand, in recent years, there is a demand for a high-resolution via hole opening for a via hole in which the ratio of the top diameter to the bottom diameter (bottom diameter / top diameter) is substantially 1 in addition to the reduction in diameter. However, it has been found that the technique described in Patent Document 1 has a problem that sufficient resolution cannot be obtained.

JP-A-10-142791 JP-A-2017-116652

  Therefore, an object of the present invention is to provide an interlayer insulating layer which has excellent resolution, does not easily crack at the via hole opening after the surface roughening treatment, and has excellent adhesion to circuit conductors and insulation reliability between circuits. It is an object of the present invention to provide a photosensitive curable resin composition which is effective for forming a resin.

  The present inventors have intensively studied to realize the above object. As a result, the above-mentioned object is realized by using an inorganic filler having a specific average particle diameter as the inorganic filler that is decomposed or dissolved by the roughening agent, and by using a spherical inorganic filler that is not decomposed or dissolved by the roughening agent. The inventors have found that the present invention can be performed, and have completed the present invention.

  That is, the curable resin composition of the present invention is decomposed or dissolved by (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting compound, and (D-1) a roughening agent. And (D-2) a spherical inorganic filler that is not decomposed or dissolved by the roughening agent.

  In the curable resin composition of the present invention, the spherical inorganic filler that is not decomposed or dissolved by the roughening agent (D-2) is preferably silica and / or alumina.

  In the curable resin composition of the present invention, the average particle diameter of the (D-2) spherical inorganic filler that is not decomposed or dissolved by the roughening agent is preferably 4 μm or less.

  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, an interlayer insulating layer having excellent resolution, and hardly generating cracks in via hole openings after surface roughening treatment, and having excellent adhesion to circuit conductors and insulation reliability between circuits is provided. It is possible to provide a photosensitive curable resin composition that is effective for forming.

  The curable resin composition of the present invention comprises (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting compound, and (D-1) an average which is decomposed or dissolved by a roughening agent. An inorganic filler having a particle diameter of 0.5 to 6 μm (hereinafter, also referred to as “(D-1) inorganic filler”) and (D-2) a spherical inorganic filler that is not decomposed or dissolved by a roughening agent (hereinafter, “ (Also referred to as “D-2) inorganic filler”).

  In the present invention, by using the inorganic fillers (D-1) and (D-2) together, it is possible to suppress the cracks at the via hole opening. Although the detailed mechanism is not clear, it is speculated that even if a crack occurs due to the strain generated in the surface roughening process, the spherical inorganic filler will fall off at the point where the crack has progressed, suppressing the progress of the crack. You. Furthermore, by setting the average particle diameter of the inorganic filler of (D-1) to 0.5 to 6 μm, the cured product not only has excellent resolution but also has excellent adhesion to a copper plating layer and excellent insulation. Can be formed.

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

[(A) Alkali-soluble resin]
The curable resin composition of the present invention contains (A) an alkali-soluble resin. As the alkali-soluble resin, a resin containing at least one functional group selected from a phenolic hydroxyl group, a thiol group, a sulfonyl group, and a carboxyl group and soluble in an alkaline solution can be used. Can be used a compound having two or more phenolic hydroxyl groups, a carboxyl group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, a compound having two or more thiol groups, and a compound having a sulfo group. In particular, a carboxyl group-containing resin is more preferable as the alkali-soluble resin.
The carboxyl group-containing resin preferably has an ethylenically unsaturated group in the molecule in addition to the carboxyl group from the viewpoint of photocurability and development resistance. As the ethylenically unsaturated group, a (meth) acryloyl group is preferable. As used herein, the term “(meth) acryloyl group” is a general term for an acryloyl group, a methacryloyl group, and a mixture thereof, and the same applies to other similar expressions.

  Examples of the carboxyl group-containing resin include the following compounds (which may be oligomers or polymers).

  (1) A carboxyl group-containing resin obtained by copolymerization of 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.

  (2) Diisocyanates such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate and aromatic diisocyanate, and carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and polycarbonate-based polyols and polyether-based A carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diol compound such as a polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, and a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

  (3) Diisocyanate compounds such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, and aromatic diisocyanate, and polycarbonate polyol, polyether polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride with a terminal of a urethane resin by a polyaddition reaction of a diol compound such as an alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

  (4) Diisocyanate and a bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin, etc. A photosensitive carboxyl group-containing urethane resin obtained by a polyaddition reaction of a (meth) acrylate or a partial acid anhydride modified product thereof, a carboxyl group-containing dialcohol compound and a diol compound.

  (5) During the synthesis of the resin of the above (2) or (4), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added, and a terminal ( (Meth) Acrylated carboxyl group-containing urethane resin.

  (6) During the synthesis of the resin (2) or (4), one isocyanate group and one or more (meth) acryloyl groups in a molecule such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. Carboxyl group-containing urethane resin having terminal (meth) acrylated by adding a compound having the same.

  (7) Photosensitivity obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to a hydroxyl group present in a side chain. Carboxyl group-containing resin.

  (8) A photosensitive carboxyl group obtained by reacting (meth) acrylic 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 resin.

  (9) 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.

  (10) 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.

  (11) 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 is reacted with an unsaturated group-containing monocarboxylic acid to obtain a reaction product. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride with a reaction product.

  (12) A compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, in an epoxy compound having a plurality of epoxy groups in one molecule, and (meth) It reacts with an unsaturated group-containing monocarboxylic acid such as acrylic acid, and reacts with an alcoholic hydroxyl group of the obtained reaction product to maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipine. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as an acid.

  (13) In addition to the resin of any one of (1) to (12) above, one epoxy group and one or more (meth) acryloyl in a molecule of glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, or the like. A photosensitive carboxyl group-containing resin obtained by adding a compound having a group.

  (14) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth) acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.

  (15) An unsaturated monocarboxylic acid is reacted with a copolymer of a compound having one epoxy group and an unsaturated double bond in each molecule, and a copolymer of a compound having an unsaturated double bond. A photosensitive carboxyl group-containing resin obtained by reacting a saturated or unsaturated polybasic anhydride with a secondary hydroxyl group.

  (16) After reacting a saturated or unsaturated polybasic anhydride with a hydroxyl group-containing polymer, a compound having one epoxy group and one unsaturated double bond in each molecule is reacted with the generated carboxylic acid. A photosensitive hydroxyl- and carboxyl-containing resin obtained by the reaction.

  Since the carboxyl group-containing resin as described above has a large number of carboxyl groups in the side chain of the backbone polymer, development with an alkaline aqueous solution becomes possible.

  Further, as the alkali-soluble resin, an alkali-soluble resin having at least one amideimide structure represented by the following formula (a) or (b) can be suitably used. By containing a resin having an imide bond directly bonded to a cyclohexane ring or a benzene ring, a cured product having higher toughness and heat resistance can be obtained. In particular, an amide imide resin having a structure represented by the following (a) is excellent in light transmittance, so that the resolution of the resin composition can be further improved. The alkali-soluble resin having at least one amide imide structure represented by the following formula (a) or (b) preferably has transparency. For example, the transmittance of light having a wavelength of 365 nm is 70 in a dry coating film of 25 μm. % Is preferable.

  The content of the structures of the formulas (a) and (b) in the alkali-soluble resin having the amide imide structure is preferably from 10 to 70% by mass. By using such a resin, it is possible to obtain a cured product that is excellent in solvent solubility and excellent in heat resistance, physical properties such as tensile strength and elongation, and dimensional stability. Preferably it is 10-60 mass%, More preferably, it is 20-50 mass%.

（式（ａ１）および（ａ２）中、それぞれ、Ｒは１価の有機基であり、Ｈ、ＣＦ_３またはＣＨ_３であることが好ましく、Ｘは直接結合または２価の有機基であり、直接結合、ＣＨ_２またはＣ（ＣＨ_３）_２等のアルキレン基であることが好ましい。）で表される構造を有する樹脂が、引張強度や伸度等の物性および寸法安定性に優れるため好ましい。溶解性や機械物性の観点から、式（ａ）の構造を有するアミドイミド樹脂として、式（ａ１）および（ａ２）の構造を１０〜１００質量％有する樹脂を好適に用いることができる。より好ましくは２０〜８０質量％である。 As the alkali-soluble resin having an amide imide structure represented by the formula (a), particularly, the following formula (a1) or (a2)

(In the formulas (a1) and (a2), R is a monovalent organic group, preferably H, CF ₃ or CH ₃ , and X is a direct bond or a divalent organic group. It is preferable to use a resin having a structure represented by a bond, an alkylene group such as CH ₂ or C (CH ₃ ) ₂ ) because of excellent physical properties such as tensile strength and elongation and dimensional stability. From the viewpoint of solubility and mechanical properties, as the amide imide resin having the structure of the formula (a), a resin having the structures of the formulas (a1) and (a2) in an amount of 10 to 100% by mass can be suitably used. More preferably, the content is 20 to 80% by mass.

  Further, as the amide imide resin having the structure of the formula (a), an amide imide resin containing the structures of the formulas (a1) and (a2) in an amount of 5 to 100 mol% can be preferably used from the viewpoint of solubility and mechanical properties. . It is more preferably from 5 to 98 mol%, further preferably from 10 to 98 mol%, particularly preferably from 20 to 80 mol%.

（式（ｂ１）および（ｂ２）中、それぞれ、Ｒは１価の有機基であり、Ｈ、ＣＦ_３またはＣＨ_３であることが好ましく、Ｘは直接結合または２価の有機基であり、直接結合、ＣＨ_２またはＣ（ＣＨ_３）_２などのアルキレン基であることが好ましい。）で表される構造を有する樹脂が、引張強度や伸度等の機械的物性に優れる硬化物が得られることから好ましい。溶解性や機械物性の観点から、式（ｂ）の構造を有するアミドイミド樹脂として、式（ｂ１）および（ｂ２）の構造を１０〜１００質量％有する樹脂を好適に用いることができる。より好ましくは２０〜８０質量％である。 As the alkali-soluble resin having an amide imide structure represented by the formula (b), particularly, the alkali-soluble resin represented by the formula (b1) or (b2)

(In the formulas (b1) and (b2), R is a monovalent organic group, preferably H, CF ₃ or CH ₃ , and X is a direct bond or a divalent organic group. A resin having a structure represented by a bond, preferably an alkylene group such as CH ₂ or C (CH ₃ ) ₂ ) can provide a cured product having excellent mechanical properties such as tensile strength and elongation. Is preferred. From the viewpoint of solubility and mechanical properties, as the amide imide resin having the structure of the formula (b), a resin having the structures of the formulas (b1) and (b2) in an amount of 10 to 100% by mass can be suitably used. More preferably, the content is 20 to 80% by mass.

  As the amide imide resin having the structure of the formula (b), an amide imide resin containing the structures of the formulas (b1) and (b2) in an amount of 2 to 95 mol% can also be preferably used because of exhibiting good mechanical properties. More preferably, it is 10 to 80 mol%.

  The alkali-soluble resin having an amide imide structure can be obtained by a known method. The amide imide resin having the structure of the formula (a) can be obtained, for example, using a diisocyanate compound having a biphenyl skeleton and cyclohexane polycarboxylic anhydride.

  Examples of the diisocyanate compound having a biphenyl skeleton include 4,4′-diisocyanate-3,3′-dimethyl-1,1′-biphenyl and 4,4′-diisocyanate-3,3′-diethyl-1,1′-biphenyl. 4,4'-diisocyanate-2,2'-dimethyl-1,1'-biphenyl, 4,4'-diisocyanate-2,2'-diethyl-1,1'-biphenyl, 4,4'-diisocyanate 3,3′-ditrifluoromethyl-1,1′-biphenyl, 4,4′-diisocyanate-2,2′-ditrifluoromethyl-1,1′-biphenyl and the like. In addition, an aromatic polyisocyanate compound such as diphenylmethane diisocyanate may be used.

  Examples of the cyclohexane polycarboxylic anhydride include cyclohexane tricarboxylic anhydride and cyclohexane tetracarboxylic anhydride.

  The amide imide resin having the structure of the formula (b) can be obtained, for example, by using the above diisocyanate compound having a biphenyl skeleton and an aqueous polycarboxylic acid having two acid anhydride groups.

  Examples of the aqueous polycarboxylic acid having two acid anhydride groups include pyromellitic dianhydride, benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride, diphenylether-3,3', 4,4'-tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, biphenyl-3,3 ', 4,4'-tetracarboxylic dianhydride, biphenyl- 2,2 ', 3,3'-tetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 1,1 -Bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane Dianhydride, 2,3- Bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylene glycol bisanhydro And alkylene glycol bisanhydroxy trimellitate such as trimellitate.

  Specific examples of the alkali-soluble resin having the amide imide structure include Unidic V-8000 series manufactured by DIC Corporation and SOXR-U manufactured by Nippon Advanced Paper Industry Co., Ltd.

As the alkali-soluble resin (A) described above, one kind may be used alone, or a mixture of two or more kinds may be used.
The acid value of such an alkali-soluble resin is preferably in the range of 20 to 120 mgKOH / g, and more preferably in the range of 30 to 100 mgKOH / g. When the acid value of the alkali-soluble resin is in the above range, favorable alkali development can be performed, and a normal cured product pattern can be formed.
The weight average molecular weight of such an alkali-soluble resin varies depending on the resin skeleton, but is generally preferably from 1,500 to 150,000. When the weight average molecular weight is 1,500 or more, the tack-free property of the dried coating film, the moisture resistance of the coating film after exposure are good, and the resolution is better. On the other hand, when the weight average molecular weight is 150,000 or less, the developability and the storage stability are good. More preferably, it is 1,500 to 50,000.

(Compound having an ethylenically unsaturated group)
The curable resin composition of the present invention may contain a compound having an ethylenically unsaturated group in addition to the component (A). In this specification, when another component including the component (A) has an ethylenically unsaturated group, such a component is excluded from the “compound having an ethylenically unsaturated group”.

As the compound having an ethylenically unsaturated group, a known and commonly used photopolymerizable oligomer or photopolymerizable vinyl monomer can be used.
Examples of the photopolymerizable oligomer include an unsaturated polyester-based oligomer and a (meth) acrylate-based oligomer. Examples of the (meth) acrylate oligomer include epoxy (meth) acrylates such as phenol novolak epoxy (meth) acrylate, cresol novolak epoxy (meth) acrylate, and bisphenol-type epoxy (meth) acrylate, urethane (meth) acrylate, and epoxy urethane (meth). A) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate, and the like.

  Examples of the photopolymerizable vinyl monomer include styrene derivatives such as styrene, chlorostyrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, vinyl-n-butyl ether, and vinyl. Vinyl ethers such as -t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, and triethylene glycol monomethyl vinyl ether; acrylamide, methacrylamide, N- Hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N- (Meth) acrylamides such as toxicmethylacrylamide; allyl compounds such as triallyl isocyanurate, diallyl phthalate, diallyl isophthalate; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate Esters of (meth) acrylic acid such as, isobornyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) Hydroxyalkyl (meth) acrylates such as acrylate; alkoxyalkylene such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Recohol mono (meth) acrylates; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylates, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropanetri Alkylene polyol poly (meth) acrylates such as (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, ethoxylated triacrylate Polyoxyalkylene glycol poly (meth) acrylates such as methylolpropane triacrylate and propoxylated trimethylolpropane tri (meth) acrylate ; Poly (meth) acrylates such as hydroxypivalic acid neopentyl glycol ester di (meth) acrylate; and tris [(meth) acryloxyethyl] isocyanurate rate poly (meth) acrylates such as isocyanurate.

  The compound having such an ethylenically unsaturated group is preferably a compound having a (meth) acryloyl group, that is, a (meth) acrylate compound. Further, the (meth) acrylate compound is preferably bifunctional or more, since the heat resistance becomes better. Further, it is preferable that the (meth) acrylate compound has an acrylic equivalent of 100 or more because the elongation becomes better, the halation is further suppressed, and the cured product is less likely to warp.

  One of such compounds having an ethylenically unsaturated group may be used alone, or two or more may be used in combination. The compounding amount of the compound having an ethylenically unsaturated group is 1 to 80 parts by mass, more preferably 2 to 70 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content.

[(B) Photopolymerization initiator]
As the photopolymerization initiator, any known photopolymerization initiator can be used.

  Examples of the photopolymerization initiator include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- ( 2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6- Trimethylbenzoyl) -phenylphosphine oxide Bisacylphosphine oxides such as Omnirad 819) manufactured by IGM; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid Monoacylphosphine oxides such as methyl ester, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphinate, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO, manufactured by IGM) 1-hydroxy-cyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, -Hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropane Benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p- Benzophenones such as methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenyla Tophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (manufactured by IGM, Omnirad 369), 2- (dimethylamino) -2-[(4-methylphenyl) methyl)- Acetophenones such as 1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothio Thioxanthones such as Sandton and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone and the like Anthraquinones; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate and ethyl p-dimethylbenzoate; -Octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazo Oxime esters such as l-3-yl]-, 1- (O-acetyloxime) (IRGACURE OXE-02, manufactured by BASF Japan); bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyr-1-) Yl) ethyl) phenyl] titanocenes such as titanium; phenyldisulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

  The amount of the photopolymerization initiator is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content.

(Photopolymerization inhibitor)
The curable resin composition of the present invention preferably contains a photopolymerization inhibitor in addition to the components (A) and (B), and suppresses light scattering during exposure (so-called halation) to achieve resolution. Performance can be improved.

The photopolymerization inhibitor is not particularly limited, and a known and commonly used one can be used.
Specifically, p-benzoquinone, naphthoquinone, di-t-butyl paracresol, hydroquinone monomethyl ether, α-naphthol, 4-methoxy-1-naphthol, acetamidine acetate, hydrazine hydrochloride, trimethylbenzylammonium chloride, dimethyl Examples include nitrobenzene, picric acid, quinone dioxime, pyrogallol, tannic acid, resorudine, cuperon, phenothiazine and the like. Of these, quinone-based photopolymerization inhibitors such as p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether, and quinone dioxime, and naphthol-based photopolymerization inhibitors such as α-naphthol and 4-methoxy-1-naphthol are preferred. One photopolymerization inhibitor may be used alone, or two or more photopolymerization inhibitors may be used in combination.

  The compounding amount of the photopolymerization inhibitor is 0.005 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content.

[(C) thermosetting compound]
The curable resin composition of the present invention contains (C) a thermosetting compound. This thermosetting compound can improve various properties such as heat resistance and insulation reliability of the cured product by further thermosetting the photocured composition. Examples of such thermosetting compounds include amino resins, melamine resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, known and commonly used thermosetting compounds such as episulfide resins. Can be used. Among them, epoxy compounds, oxetane compounds and maleimide compounds are preferably used, and these may be used in combination.

  As the epoxy compound, a known compound having one or more epoxy groups can be used, and a compound having two or more epoxy groups is preferable. For example, monoepoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, glycidyl (meth) acrylate, bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin , Alicyclic epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol Diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, triglycidyl tris (2-h Rokishiechiru) a compound having two or more epoxy groups in one molecule, such as a isocyanurate.

  As the oxetane compound, known and common compounds having an oxetanyl group can be used. For example, 3-ethyl-3-hydroxymethyloxetane (OXT-101 manufactured by Toagosei Co., Ltd.), 3-ethyl-3- (phenoxymethyl) Oxetane (OXT-211 manufactured by Toagosei Co., Ltd.), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (OXT-212 manufactured by Toagosei Co., Ltd.), 1,4-bis} [(3-ethyl-3 [Oxetanyl) methoxy] methyl} benzene (OXT-121 manufactured by Toagosei Co., Ltd.), and bis (3-ethyl-3-oxetanylmethyl) ether (OXT-221 manufactured by Toagosei Co., Ltd.). Further, phenol novolak type oxetane compounds and the like are also included. The oxetane compound may be used in combination with the above epoxy compound, or may be used alone.

As the maleimide compound, known and commonly used compounds such as polyfunctional aliphatic / alicyclic maleimide and polyfunctional aromatic maleimide can be used, and among them, a bifunctional or higher functional maleimide compound (polyfunctional maleimide compound) is preferable.
Examples of the polyfunctional aliphatic / alicyclic maleimide include N, N′-methylene bismaleimide, N, N′-ethylene bismaleimide, tris (hydroxyethyl) isocyanurate, and aliphatic / alicyclic amaleimide carboxylic acid. Maleimide ester compound having an isocyanurate skeleton obtained by dehydration esterification of isocyanurate skeleton; polyisocyanurate skeleton such as a maleimide urethane compound having an isocyanurate skeleton obtained by urethanizing tris (carbamatehexyl) isocyanurate and an aliphatic / alicyclic maleimide alcohol Maleimides; isophorone bis urethane bis (N-ethyl maleimide), triethylene glycol bis (maleimide ethyl carbonate), dehydration esterification of aliphatic / alicyclic maleimide carboxylic acid and various aliphatic / alicyclic polyols, or fats / Alicyclic maleimide carboxylic acid ester and various aliphatic / alicyclic polymaleimide ester compounds obtained by transesterification of aliphatic / alicyclic alicyclic polyol with aliphatic / alicyclic maleimide carboxylic acid ester and various fats / Alicyclic polymaleimide ester compounds obtained by ether ring-opening reaction of aliphatic / alicyclic polyepoxide; urethanization of aliphatic / alicyclic maleimide alcohol and various aliphatic / alicyclic polyisocyanates There are aliphatic / alicyclic polymaleimide urethane compounds obtained by the reaction.

As the polyfunctional aromatic maleimide, aromatic polymaleimide ester compounds obtained by dehydration esterification of maleimide carboxylic acid and various aromatic polyols or transesterification of maleimide carboxylic acid ester with various aromatic polyols; maleimide Aromatic polymaleimide ester compounds obtained by ether-ring-opening reaction between carboxylic acid and various aromatic polyepoxides; Aromatic polymaleimide urethane compounds obtained by urethanizing maleimide alcohol with various aromatic polyisocyanates And aromatic polyfunctional maleimides.
Among such polyfunctional aromatic maleimides, liquid polyfunctional aromatic maleimides are more preferable in that the elongation ratio becomes better. Here, the liquid polyfunctional aromatic maleimide is a polyfunctional aromatic maleimide whose viscosity at 60 ° C. and 5 rpm is measured with a cone plate type viscometer (TVH-33H manufactured by Toki Sangyo Co., Ltd.) and is 50,000 cp or less. Refers to maleimide.

  One of the thermosetting compounds described above may be used alone, or two or more thereof may be used in combination. The compounding amount of the thermosetting compound is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 100 parts by mass, and more preferably 1 to 60 parts by mass based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content. Parts by mass are more preferred. In particular, when a maleimide compound is compounded as a thermosetting compound, the compounding amount of the maleimide compound is preferably from 0.1 to 50 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content. Preferably it is 0.2 to 20 parts by mass.

(Heat curing catalyst)
The curable resin composition of the present invention can contain a thermosetting catalyst in addition to (C) the thermosetting compound. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, Imidazole derivatives such as-(2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethyl Amine compounds such as benzylamine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic dihydrazide and sebacic dihydrazide; and phosphorus compounds such as triphenylphosphine can be used.

  Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino Thermosetting catalysts that also function as adhesion-imparting agents such as S-triazine derivatives such as -S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct are also provided. Can be used.

  Commercially available products include, for example, 2MZ-AP, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., and U-CAT3503N, U manufactured by San Apro -CAT3502T (all trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof). In particular, the present invention is not limited to these, and may be any one that promotes the reaction of a thermosetting catalyst of an epoxy compound or an oxetane compound, or a reaction of another thermosetting component. You can use it.

  The blending amount of the thermosetting catalyst is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 20 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content. When the blending amount of the thermosetting catalyst is in the range of 0.1 to 20 parts by mass, the balance between storage stability and curability is excellent.

[(D-1) Inorganic filler having an average particle diameter of 0.5 to 6 µm decomposed or dissolved by the roughening agent]
The curable resin composition of the present invention contains (D-1) an inorganic filler having an average particle diameter of 0.5 to 6 μm that is decomposed or dissolved by a roughening agent. In the present specification, at least one selected from an acid, an alkali, an oxidizing agent, and an organic solvent is used as a roughening agent. Further, the surface roughening process may also serve as the desmear process. Here, examples of the acid include hydrochloric acid, sulfuric acid, and nitric acid. Examples of the alkali include sodium hydroxide and potassium hydroxide. Examples of the oxidizing agent include sodium permanganate, potassium permanganate, potassium dichromate, ozone, and the like. Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethylsulfoxide, methoxypropanol, dimethylformamide (DMF) and the like.

  Examples of the inorganic filler that is decomposed or dissolved by the roughening agent include magnesium oxide, calcium carbonate, zirconium silicate, zirconium oxide, and calcium hydroxide, and calcium carbonate is particularly preferable.

  The average particle diameter of the inorganic filler (D-1) needs to be 0.5 to 6 μm, and preferably 0.5 to 5 μm. When the thickness is 0.5 μm or more, the adhesion to the conductor circuit is improved. When the thickness is 6 μm or less, the resolution is good, and fine conductor circuits can be formed and transmission loss can be reduced.

  The average particle diameter of the inorganic filler of (D-1) is an average particle diameter (D50) including not only the particle diameter of the primary particles but also the particle diameter of the secondary particles (aggregates), and is determined by a laser diffraction method. This is the measured D50 value. As a measuring apparatus by a laser diffraction method, there is Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. The same applies to the average particle diameter of the inorganic filler (D-2) described later.

  As the inorganic filler (D-1), one type may be used alone, or two or more types may be used in combination. The amount of the inorganic filler (D-1) is preferably 10 to 200 parts by mass, more preferably 20 to 100 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content.

[(D-2) Spherical inorganic filler not decomposed or dissolved by roughening agent]
The curable resin composition of the present invention contains (D-2) a spherical inorganic filler that is not decomposed or dissolved by the roughening agent.

  Examples of the spherical inorganic filler that is not decomposed or dissolved by the roughening agent include silica and alumina, but silica is particularly preferable.

  The inorganic filler of (D-2) may be spherical, and is not limited to a true sphere. For example, those having a sphericity of 0.8 or more measured as described below are suitable, but not limited thereto.

The sphericity is measured as follows. That is, first, a photograph of spherical silica is taken with a scanning electron microscope (SEM), and from the area and perimeter of the particles observed on the photograph, (sphericity) = {4π × (area)} (periphery) Length) Calculated as the value calculated in ² ｝. Specifically, an average value measured for 100 particles using an image processing device can be adopted.

  The average particle diameter of the inorganic filler (D-2) is preferably 4 μm or less. When the thickness is 4 μm or less, the resolution becomes better. More preferably, it is 1 μm or less.

  As the inorganic filler (D-2), one type may be used alone, or two or more types may be used in combination. The blending amount of the inorganic filler (D-2) is preferably 2 to 60 parts by mass per 100 parts by mass of the inorganic filler (D-1). When it is at most 60 parts by mass, the resolution will be better. When the amount is 2 parts by mass or more, cracking of the via hole opening after the surface roughening treatment is suppressed. More preferably, the amount is 5 to 50 parts by mass.

(Coupling agent)
The curable resin composition of the present invention can contain a coupling agent. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, or the like can be used. Among them, a silane coupling agent is preferable. Examples of the organic reactive group of the coupling agent include an ethylenically unsaturated group (unsaturated hydrocarbon group) such as a vinyl group and a (meth) acrylic group, an alkoxy group, an epoxy group, an amino group, a thiourea group, a mercapto group, and an isocyanate. Examples thereof include a group, an imidazole group, a thiazole group, and a triazole group. Particularly, a thiourea group and an ethylenically unsaturated group (an unsaturated hydrocarbon group) such as a vinyl group and a (meth) acryl group are preferable. One type of coupling agent may be used alone, or two or more types may be used in combination.

  The amount of the silane coupling agent is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, in terms of solids, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solids. It is.

(Additive)
The curable resin composition of the present invention may optionally contain known and commonly used additives. Examples of the additives include inorganic fillers other than (D-1) and (D-2), organic fillers, adhesion-imparting agents, acrylic and silicone-based leveling agents, defoamers, thermal polymerization inhibitors, and ultraviolet absorbers. Agents, flame retardants, antistatic agents, thixotropic agents and the like. If necessary, a metal hydroxide such as titanium oxide, a metal oxide, or aluminum hydroxide can be blended as an extender pigment for the purpose of imparting light reflectivity and flame retardancy. Further, known and commonly used coloring agents such as red, blue, green, yellow, white, and black can be added. This colorant may be any of a pigment, a dye, and a pigment.

(Organic solvent)
The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when forming a resin layer by applying the composition to a support film, and the like.
Examples of the organic solvent include 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, and propylene glycol monomethyl. Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl Carbitol acetate, propylene glycol monomethyl ether acetate, Propylene glycol monomethyl ether acetate, esters such as propylene carbonate; octane, aliphatic hydrocarbons decane; petroleum ether, petroleum naphtha, and petroleum solvents such as solvent naphtha, organic solvents conventionally known can be used. One of these organic solvents may be used alone, or two or more thereof may be used in combination.

  The curable resin composition of the present invention may be used as a dry film or as a liquid. When used as a liquid, it may be one-pack or two-pack or more.

[Dry film]
The curable resin composition of the present invention may be in the form of a dry film comprising a support (carrier) film and a dried resin layer formed of the curable resin composition formed on the support film. .

  As such a support film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, and the like can be used. The thickness of the support film is not particularly limited, but is generally selected appropriately in the range of 10 to 150 μm.

The dry film of the present invention can be manufactured, for example, as follows.
First, the above-mentioned curable resin composition constituting the dry film of the present invention was diluted with an organic solvent to adjust to an appropriate viscosity, and then a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, and a reverse coater were used. It is applied to a uniform thickness on a support film by a coater, a transfer roll coater, a gravure coater, a spray coater or the like.
Next, by drying the coating film of the curable resin composition applied on the support film at a temperature of 50 to 130 ° C. for 1 to 30 minutes, a resin layer composed of a dried coating film was formed on the support film. Films can be manufactured. Here, the coating film thickness is not particularly limited, but is generally appropriately selected in a range of 10 to 150 μm, preferably 15 to 60 μm as a film thickness after drying.

  The dry film of the present invention produced as described above has a wavelength of 365 nm of the dry film composed of a PET film having a thickness of 30 to 50 μm and a curable resin composition layer (resin layer) having a resin layer thickness of 15 μm. Is preferably 90% or less. By having such light transmittance, the photocurability of the resin layer is stabilized and the resolution is improved.

  In the dry film of the present invention, the minimum value of the melt viscosity of the resin layer at 70 ° C to 120 ° C is preferably 10 to 2000 dPa · s. By having such a melt viscosity, sufficient filling properties can be obtained for the unevenness of the circuit in the laminate.

Dry film of the present invention, after forming a resin layer made of a curable resin composition on the support film, for the purpose of preventing dust from adhering to the surface of the resin layer, further on the surface of the resin layer, It is preferable to laminate a peelable protective (cover) film.
The peelable protective film only needs to have a smaller adhesive strength between the resin layer and the support film, and for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, or the like can be used.

  The dry film of the present invention may be one in which a resin layer is formed by applying and drying a curable resin composition on the protective film, and the support film is laminated on the surface of the resin layer. That is, in the present invention, any of a support film and a protective film may be used as a film on which the curable resin composition is applied when producing a dry film.

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

[Printed wiring board]
The printed wiring board of the present invention has the curable resin composition of the present invention or the cured product of the dry film resin layer of the present invention. The printed wiring board of the present invention can be manufactured, for example, as follows.
First, the dry film of the present invention is laminated on a wiring board on which a circuit is formed, using a laminator or the like so that the resin layer is on the substrate side. In this step, instead of laminating the dry film of the present invention, the curable resin composition of the present invention is applied on a wiring board on which a circuit is formed, and dried to form a tack-free resin layer. Is also good.
Here, examples of the wiring board include a printed wiring board and a flexible printed wiring board in which circuits such as copper are formed in advance on various base materials such as glass cloth epoxy and nonwoven cloth epoxy.

Next, the support film is peeled off from the resin layer formed on the wiring substrate, or active energy rays are irradiated from above the support film through a photomask having a predetermined pattern to perform pattern exposure.
Here, as an exposure device used for irradiating active energy rays, any device that mounts a high-pressure mercury lamp or a metal halide lamp as a light source and irradiates ultraviolet rays in a range of 350 to 450 nm may be used. Imaging exposure) apparatus can also be used. The exposure dose varies depending on the film thickness and the like, but is generally in the range of 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

Next, the unexposed portion is developed with an alkaline aqueous solution (for example, an aqueous solution of 0.3 to 3% by mass of sodium carbonate) to form a patterned photocured product.
Here, as a developing method, a dipping method, a shower method, a spray method, or the like can be used. As a developing solution, an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, or potassium carbonate can be used. it can.

Further, the obtained patterned cured product is cured by heating (for example, 100 to 180 ° C.) or by irradiating with an active energy ray to thereby provide a cured film having excellent properties such as adhesion and hardness. Can be formed. Thus, an interlayer insulating layer having a finer and smaller-diameter via hole opening can be formed on the wiring board.
Here, heat treatment such as heat curing can be performed using a hot air circulation drying oven, an IR oven, or the like.

  Further, if necessary, the conductor circuit including the via hole and the interlayer insulating layer are alternately built up, and finally a solder resist is formed to manufacture a printed wiring board.

  As described above, the curable resin composition of the present invention is useful as a material for an interlayer insulating layer, but is also used for forming a pattern layer as a permanent coating of a printed wiring board such as a solder resist or a coverlay. Can also be used. In addition, the curable resin composition of the present invention is excellent in resolution and has excellent adhesion (high peel strength) to a conductor circuit formed by copper plating, while having low surface roughness. Therefore, it can be suitably used as an interlayer insulating material of a semiconductor package in which fine circuit formation and reduction of transmission loss are required. Further, the curable resin composition of the present invention is preferably used for a printed wiring board of high-density wiring, since cracks in via hole openings after the surface roughening treatment are suppressed and insulation between via holes is improved. be able to.

  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 and Comparative Examples. In the following, “parts” and “%” are based on mass unless otherwise specified.

[Synthesis of alkali-soluble resin]
(Synthesis Example 1: Alkali-soluble acrylate-added amide imide resin (alkali-soluble resin A-1))
103.5 g of diethylene glycol monoethyl ether acetate, 222.0 g of isophorone diisocyanate, and 192.0 g of trimellitic anhydride were charged into a four-necked flask equipped with a stirrer, a thermometer, and a condenser, and heated to 120 ° C. while stirring. did. Vigorous bubbling began around 60 ° C., and the contents of the flask gradually became transparent. The reaction was carried out at 120 ° C for 5 hours, and the system was cooled to 40 ° C when the NCO% in the system became 9.0% by mass. Further, 166.4 g of diethylene glycol monoethyl ether acetate and 1.0 g of methylhydroquinone were added, and 234.7 g of Aronix M-305 (manufactured by Toagosei Co., Ltd., OH equivalent: 467.5) was added thereto. The temperature was raised to 80 ° C. After reacting at 80 ° C. for 9 hours, it was confirmed by infrared absorption spectrum that the absorption of isocyanate at 2270 cm ⁻¹ had disappeared, and a resin solution of alkali-soluble resin A-1 as a pale yellow transparent liquid was obtained. The nonvolatile content was 42%, the acid value of the solid was 68.4 mgKOH / g, and the weight average molecular weight was about 1,524 (in terms of polystyrene).

(Synthesis Example 2: Photosensitive resin containing phenol starting type carboxyl group (alkali-soluble resin A-2))
In an autoclave equipped with a thermometer, a nitrogen-introducing device, an alkylene oxide-introducing device, and a stirring device, 119.4 g of a novolak-type cresol resin (Shownol CRG951, OH equivalent: 119.4) and potassium hydroxide 1.19 g Then, 119.4 g of toluene and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually dropped, and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to the reaction solution and mixed to neutralize potassium hydroxide. The nonvolatile content was 62.1%, and the hydroxyl value was 182.2 g / eq. A propylene oxide reaction solution of novolak cresol resin was obtained. This was an average of 1.08 mol of alkylene oxide added per equivalent of phenolic hydroxyl group.
Next, 293.0 g of an alkylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were added to a stirrer, a thermometer and air. The reactor was equipped with a blowing tube, air was blown at a rate of 10 ml / min, and the mixture was reacted at 110 ° C. for 12 hours with stirring. 12.6 g of water was distilled off as an azeotrope with the water generated by the reaction. Thereafter, the mixture was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while replacing the toluene with 118.1 g of diethylene glycol monoethyl ether acetate using an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 g of the obtained novolak type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. While stirring, 60.8 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours to obtain a resin solution of carboxyl group-containing photosensitive resin A-2. The nonvolatile content was 65%, the acid value of the solid was 88 mg KOH / g, and the weight average molecular weight was about 8,000 (polystyrene equivalent).

(Synthesis Example 3: Epoxy-started carboxyl group-containing photosensitive resin (alkali-soluble resin A-3))
In a four-necked flask equipped with a stirrer and a reflux condenser, 220 g of cresol novolak type epoxy resin (Epiclon N-695, epoxy equivalent: 220, manufactured by Dainippon Ink and Chemicals, Inc.) was added, and 214 g of carbitol acetate was added. Heated and dissolved. Next, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of dimethylbenzylamine as a reaction catalyst were added. This mixture was heated to 95 to 105 ° C., and 72 g of acrylic acid was gradually added dropwise to react for 16 hours. The reaction product was cooled to 80 to 90 ° C., and 106 g of tetrahydrophthalic anhydride was added, reacted for 8 hours, and taken out after cooling.
A resin solution of the carboxyl group-containing photosensitive resin A-3 thus obtained was obtained. The nonvolatile content was 65%, the acid value of the solid content was 100 mgKOH / g, and the weight average molecular weight was about 3,500 (in terms of polystyrene).

(Synthesis Example 4: Carboxyl group-containing copolymer photosensitive resin (alkali-soluble resin A-4))
In a 2-liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube, 900 g of diethylene glycol dimethyl ether and t-butylperoxy 2-ethylhexanoate (Perbutyl O, manufactured by NOF CORPORATION) After charging 21.4 g and raising the temperature to 90 ° C., 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (Placcel FM1 manufactured by Daicel Chemical Industries, Ltd.) were added to bis (4 (T-butylcyclohexyl) peroxydicarbonate (Perroyl TCP manufactured by NOF CORPORATION) together with 21.4 g was dropped into diethylene glycol dimethyl ether over 3 hours, and aged for 6 hours to obtain a carboxyl group-containing copolymer resin solution. . The reaction was performed under a nitrogen atmosphere.
Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (Cyclomer A200 manufactured by Daicel Chemical Industries, Ltd.), 3.6 g of dimethylbenzylamine, and 1.80 g of hydroquinone monomethyl ether were added to the carboxyl group-containing copolymer resin solution. The temperature was raised to ° C. and the mixture was stirred to carry out a ring-opening addition reaction of epoxy. After 16 hours, a resin solution of the carboxyl group-containing copolymerized photosensitive resin A-4 was obtained. The nonvolatile content was 53.8%, the acid value of the solid was 108.9 mgKOH / g, and the weight average molecular weight was 25,000 (in terms of polystyrene).

(Examples 1 to 12, Comparative Examples 1 to 4)
According to the formulations shown in Tables 1 and 2 below, each component was blended, preliminarily mixed with a stirrer, kneaded and dispersed with a three-roll mill, and the curable resins of Examples 1 to 12 and Comparative Examples 1 to 4 A composition was prepared. In addition, the compounding quantity in a table | surface shows a mass part.

* 1: Alkali-soluble resin A-1 synthesized in Synthesis Example 1 above
* 2: Alkali-soluble resin A-2 synthesized in Synthesis Example 1 above
* 3: Alkali-soluble resin A-3 synthesized in Synthesis Example 1 above
* 4: Alkali-soluble resin A-4 synthesized in Synthesis Example 1 above
* 5: Omnirad TPO (acylphosphine oxide-based photopolymerization initiator) manufactured by IGM
* 6: DIC HP-7200 (dicyclopentadiene type epoxy resin)
* 7: Brilliant 1500 (average particle size 0.15 μm) manufactured by Shiraishi Calcium Co., Ltd.
* 8: Softon 3200 manufactured by Shiroishi Calcium Co. (average particle size 0.70 μm)
* 9: Softon 2600 manufactured by Shiraishi Calcium Co. (average particle diameter 0.85 μm)
* 10: Softon 2200 manufactured by Shiraishi Calcium Co. (average particle size 1.0 μm)
* 11: BF-100 manufactured by Shiraishi Calcium Co. (average particle diameter 3.6 μm)
* 12: BF-200 manufactured by Shiraishi Calcium Co. (average particle size 5.0 μm)
* 13: BF-300 manufactured by Shiraishi Calcium Co. (average particle diameter 8.0 μm)
* 14: SO-E2 manufactured by Admatechs (average particle size 0.55 μm)
* 15: SO-E6 manufactured by Admatechs (average particle size 2.0 μm)
* 16: DAW-03 manufactured by Denka Corporation (average particle size: 4.0 μm)
* 17: Fuselex WX manufactured by Tatsumori (average particle size 1.0 μm)
* 18: X-12-1116 manufactured by Shin-Etsu Chemical Co., Ltd. (thiourea skeleton-containing silane coupling agent)
* 19: KBM-503 (3-methacryloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
* 20: QS-30 (4-methoxy-1-naphthol) manufactured by Kawasaki Chemical Industries, Ltd.

(Production of dry film)
The obtained photocurable resin compositions of Examples and Comparative Examples were coated on a support film (PET film, Cosmo Shine A4100, manufactured by Toyobo Co., Ltd., 50 μm in thickness), dried at 80 ° C. for 20 minutes, and dried to a thickness of 20 μm. A resin layer made of the photocurable resin composition was formed. Next, a protective film was laminated on the resin layer to produce a dry film for evaluation test.

(Resolution)
The protective film of the dry film for evaluation test obtained in each of the examples and comparative examples was peeled off, and was laminated on a copper solid substrate at a temperature of 70 ° C. using Nikko Material's CVP-300, and the evaluation test was performed. A substrate was prepared.
The evaluation test substrate was exposed to a pattern having an opening diameter of 25 μm at an exposure amount of 170 mJ / cm ² using a direct imaging exposure apparatus equipped with a high-pressure mercury lamp, and then the support film was peeled off. Developing was performed for 100 seconds using a developing solution of an aqueous solution at a spray pressure of 0.2 MPa. Thereafter, the substrate was irradiated with ultraviolet light in a UV conveyor furnace under the conditions of an integrated exposure amount of 1000 mJ / cm ² , and was further heated and cured at 180 ° C. for 60 minutes, thereby producing a resolution evaluation substrate.
With respect to the resolution evaluation substrate on which the resin layer having the pattern having the opening diameter of 25 μmφ is formed, the top diameter and the bottom diameter of the opening are observed and measured by an SEM at an angle of 45 degrees to evaluate the resolution. did. The evaluation criteria are as follows.
◎: (Bottom diameter ÷ Top diameter) is 0.8 or more and less than 0.9.
〇: (Bottom diameter ÷ Top diameter) is 0.7 or more and less than 0.8.
Δ: (Bottom diameter ÷ Top diameter) is 0.6 or more and less than 0.7.
×: (Bottom diameter ÷ Top diameter) is less than 0.6.

(Evaluation of cracks around vias)
A substrate for crack evaluation around the via was manufactured by further performing a roughening treatment described later on the substrate for evaluation for resolution manufactured in the evaluation of the resolution. A pattern having an opening diameter of 25 μmφ of the substrate for crack evaluation around the via was observed at an angle of 45 ° by SEM to evaluate the presence or absence of cracks (cracks) around the opening. The evaluation criteria are as follows.
A: No crack at the opening.
〇: Slight cracks are observed in the opening.
×: Many cracks are observed around the opening.

(Peel strength)
The entire surface of the evaluation test substrate prepared in the above evaluation of the resolution was exposed at an exposure amount of 170 mJ / cm ² using a direct imaging exposure apparatus equipped with a high-pressure mercury lamp. Developing for 100 seconds under the condition of a spray pressure of 0.2 MPa using a developing solution of an aqueous sodium carbonate solution of 0.2%. Thereafter, ultraviolet irradiation was performed in a UV conveyor furnace under the conditions of an integrated exposure amount of 1000 mJ / cm ² , and the film was cured by heating at 180 ° C. for 60 minutes.
The wiring board (cured resin layer-formed substrate) on which the cured resin layer is formed over the entire surface is subjected to a roughening treatment described later, and then a conductor layer is formed, and a peel strength measuring substrate (copper-plated substrate) Then, a cut having a width of 10 mm and a length of 100 mm is formed in the conductor layer of the peel strength measuring substrate, and one end of the cut is partially peeled off, and a tensile tester (AGS-G100W manufactured by Shimadzu Corporation) is formed. According to JIS K7127, a load (kgf / cm) measured at a tensile speed of 1.0 mm / min and a temperature of 23 ° C. was taken as the peel strength, and the adhesion was evaluated. The evaluation criteria are as follows.
：: Peel strength of 0.3 kgf / cm or more.
Δ: Peel strength of 0.15 kgf / cm or more and less than 0.3 kgf / cm.
C: Peel strength less than 0.15 kgf / cm.

Roughening treatment The above cured resin layer-formed substrate was added to a swelling solution, Swelling Dip Securigans P (aqueous solution of glycol ethers and sodium hydroxide) containing diethylene glycol monobutyl ether (manufactured by Atotech Japan) at 60 ° C. Dipped for 5 minutes. Next, as a roughening solution, a concentrate compact P (aqueous solution of KMnO ₄ : 60 g / L, NaOH: 40 g / L) manufactured by Atotech Japan was immersed at 60 ° C. for 10 minutes. Lastly, as a neutralizing solution, reduction shoulicine Securiganto P (aqueous solution of sulfuric acid) manufactured by Atotech Japan was immersed at 60 ° C. for 5 minutes. Thereafter, drying was performed at 80 ° C. for 30 minutes.

-Formation of Conductive Layer First, electroless copper plating is performed on the cured resin layer-formed substrate after the roughening treatment in the following steps 1 to 6 (copper plating step using a chemical solution manufactured by Atotech Japan). did. The thickness of the formed electroless copper plating layer was 1 μm. Next, the evaluation test substrate on which the electroless copper plating layer was formed was subjected to a heat treatment at 150 ° C. for 30 minutes, followed by copper sulfate electroplating to form a conductor layer having a thickness of 25 μm. Finally, an annealing treatment was performed at 180 ° C. for 60 minutes, and used for evaluation of adhesion.
1. Alkaline Cleaning (Cleaning of Surface of Insulating Layer and Charge Adjustment) Step Cleaning was performed at 60 ° C. for 5 minutes using Cleaning Cleaner Security 902 (trade name).
2. Soft Etching Step Treatment was performed at 30 ° C. for 1 minute using an aqueous solution of sodium sulfate acid peroxodisulfate.
3. Predip (adjustment of the charge on the surface of the insulating layer for Pd application) Step Pre. It processed at room temperature for 1 minute using Dip Neoganth B (brand name). 4. Step of Applying Activator (Applying Pd to Surface of Insulating Layer) Using Activator Neoganth 834 (trade name), treatment was performed at 35 ° C. for 5 minutes.
5. Reduction (reduction of Pd applied to the insulating layer) Step Reducer Neoganth WA (trade name) and Reducer Accelerator 810 mod. (Trade name), and treated at 30 ° C. for 5 minutes. 6. Electroless copper plating (precipitating Cu on the surface (Pd surface) of the insulating layer) Steps Basic Solution Printganth MSK-DK (trade name), Copper Solution Printganth MSK (trade name), and Stabilizer Printganth MSK-DK (trade name) And Reducer Cu (trade name) were used for a treatment at 35 ° C. for 20 minutes.

(B-HAST resistance)
The protective film of the dry film for evaluation test obtained in each of the examples and comparative examples was peeled off, and a VP substrate on which a comb-shaped electrode (line / space = 12 μm / 13 μm) was formed was coated with CVP- manufactured by Nikko Material Co., Ltd. After laminating at a temperature of 70 ° C. using a 300, using a direct imaging exposure apparatus equipped with a high-pressure mercury lamp, exposing the portions other than the electrode terminals at an exposure amount of 170 mJ / cm ² , and then peeling off the support film, Development was performed for 100 seconds under the condition of a spray pressure of 0.2 MPa using a developing solution of a mass% aqueous sodium carbonate solution. Thereafter, 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 was further heated and cured at 180 ° C. for 60 minutes to produce a B-HAST resistance evaluation substrate. A voltage of 5 V was applied from the electrode terminals of the B-HAST resistance evaluation board, and the board was placed in a high-temperature and high-humidity chamber under an atmosphere of 130 ° C. and 85% humidity to perform a HAST test in the chamber. The elapsed time when the insulation resistance in the tank became less than 10 ⁶ Ω was evaluated according to the following criteria.
◎: More than 400 hours
〇: 200-400 hours
×: less than 200 hours

  As is clear from the results shown in Table 1, with respect to Examples 1 to 12 using the dry film of the present invention, the results satisfy all of the resolution, peel strength, crack suppression around the via, and B-HAST resistance. became. On the other hand, for Comparative Example 1 in which the average particle diameter of the inorganic filler decomposed or dissolved by the roughening agent is less than 0.5 μm, sufficient peel strength was not obtained, and in Comparative Example 2 in which the average particle diameter was more than 6 μm. Cracks occurred remarkably, and the resolution and B-HAST resistance were poor. When the inorganic filler that was not decomposed or dissolved by the roughening agent was not spherical, cracks were remarkably generated as shown in Comparative Example 3, and the resolution and B-HAST resistance were poor. In Comparative Example 4 containing no inorganic filler (D-2), cracks around the via were significantly generated.

Claims (6)

(A) an alkali-soluble resin,
(B) a photopolymerization initiator,
(C) a thermosetting compound;
(D-1) an inorganic filler having an average particle diameter of 0.5 to 6 μm decomposed or dissolved by the roughening agent,
(D-2) a spherical inorganic filler that is not decomposed or dissolved by the roughening agent,
A curable resin composition comprising:   The curable resin composition according to claim 1, wherein the (D-2) spherical inorganic filler that is not decomposed or dissolved by the roughening agent is silica and / or alumina.   The curable resin composition according to claim 1 or 2, wherein the (D-2) spherical inorganic filler that is not decomposed or dissolved by the roughening agent has an average particle diameter of 4 µm or less.   A dry film comprising a resin layer obtained from the curable resin composition according to claim 1.   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.