JPWO2008114635A1 - Radiation sensitive resin composition - Google Patents

Abstract

The radiation sensitive resin composition of the present invention comprises (A) an alkali-soluble copolymer, (B) a compound having an ethylenically unsaturated double bond, (C) a compound represented by the following formula (1), and the following formula: A radiation-sensitive radical polymerization initiator containing the compound represented by (2). The radiation-sensitive resin composition of the present invention has excellent resolution, excellent adhesion to a substrate, exhibits wettability and plating resistance to a plating solution, and is cured after forming a desired plated model. The film is excellent in releasability from the substrate and is suitable as a material for forming bumps and wiring.

Description

  The present invention relates to a radiation-sensitive resin composition having excellent resolution. More specifically, a radiation-sensitive resin composition suitable for photofabrication such as wiring formation when manufacturing a circuit board such as a printed circuit board and bump formation performed when mounting a semiconductor or electronic component on a circuit board, and The present invention relates to a bump forming material and a wiring forming material using the composition.

  Photofabrication is an electroforming technology that consists mainly of chemical etching, electrolytic etching, or electroplating using a radiation-sensitive resin composition applied to the surface of a workpiece and patterning the coating film by photolithography. It is a general term for technologies for manufacturing various precision parts independently or in combination. This photofabrication has become the mainstream of current precision micromachining technology.

  In recent years, with the downsizing of electronic devices, LSIs are rapidly becoming highly integrated and multi-layered. For this reason, a multi-pin mounting method on a substrate for mounting an LSI on an electronic device is required, and bare chip mounting using a TAB method or a flip chip method has attracted attention. In such a multi-pin mounting method, it is necessary that protruding electrodes having a height of 15 μm or more, called bumps, which are connection terminals, be arranged on the substrate with high accuracy. In order to cope with further miniaturization of LSIs, it is necessary to increase the accuracy of bumps.

  Also, in the formation of wiring on a circuit board such as a printed board, high definition is required as in the case of bump formation.

  The material used when forming such a bump or wiring is sometimes called a bump forming material or a wiring forming material. The required items for the bump forming material and the wiring forming material include that a film thickness of 20 μm or more can be formed, adhesion to the substrate, and good wettability to the plating solution when plating is performed as a bump or wiring formation. And having a plating solution resistance and being easily and sufficiently peeled off with a stripping solution after plating.

  If the adhesion to the substrate is poor at the time of development, there arises a problem that the resist pattern is dropped from the substrate at the time of development as the pattern size for forming the bumps becomes finer. Further, when the wettability with respect to the plating solution is low, there arises a problem that uniform plating is not formed on the substrate.

However, conventional bump forming materials and wiring forming materials are not satisfactory in terms of adhesion to a substrate during development in photolithography, wettability to a plating solution, and resistance to plating solution. In addition, the resolution required to a higher degree could not be satisfied.
JP 2000-39709 A

  The object of the present invention is to have excellent resolution at a film thickness of 20 μm or more, excellent adhesion to the substrate, wettability to plating solution and plating resistance, and form good bumps and wiring by plating It is possible to provide a radiation-sensitive resin composition that is excellent in releasability from a substrate of a cured film after forming a desired plated model and is suitable as a material for forming a bump and wiring.

  The radiation sensitive resin composition according to the present invention includes (A) (a1) a structural unit derived from a radical polymerizable compound having a carboxyl group, (a2) a structural unit derived from a radical polymerizable compound having a phenolic hydroxyl group, And (a3) an alkali-soluble copolymer containing structural units derived from other radically polymerizable compounds, (B) a compound having at least one ethylenically unsaturated double bond, and (C) (c1) It contains a compound represented by the formula (1) and (c2) a radiation-sensitive radical polymerization initiator containing a compound represented by the following formula (2).

In formula (1), R ¹ independently represents a hydrogen atom, a methyl group or an ethyl group, R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxyl group or a phenyl group, n Represents an integer of 1 to 5.

  In formula (2), Ph independently represents a phenyl group which may have a substituent, and X independently represents a hydrogen atom or halogen.

  The radiation-sensitive radical polymerization initiator (C) may further include (c3) a compound represented by the following formula (3).

In formula (3), R ⁴ is independently a hydrogen atom, halogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, —SR ⁷ (R ⁷ represents a methyl group or an ethyl group), a hydroxyl group, or —NR. ⁸ R ⁹ (R ⁸ and R ⁹ each independently represents a methyl group or an ethyl group, or R ⁸ and R ⁹ are bonded via an atom other than carbon to form a 4- to 8-membered cyclic structure. R ⁵ and R ⁶ each independently represents a hydrogen atom, a methyl group, an ethyl group or a phenyl group, and Y represents a hydroxyl group or —NR ¹⁰ R ¹¹ (R ¹⁰ and R ¹¹ Each independently represents a methyl group or an ethyl group, or R ¹⁰ and R ¹¹ may form a 4- to 8-membered cyclic structure via an atom other than carbon, and m represents The integer of 1-5 is represented.

  The total content of the compounds (c1) and (c2) contained in the radiation-sensitive radical polymerization initiator (C) and (c3) used as necessary is 100 parts by mass of the alkali-soluble copolymer (A). It is preferable that it is 1-30 mass parts with respect to.

  The alkali-soluble copolymer (A) comprises the structural unit (a1) in an amount of 1 to 50% by mass, the structural unit (a2) in an amount of 1 to 50% by mass, and the structural unit (a3). It is preferably contained in an amount of 5 to 98% by mass (however, the total amount of the structural units (a1), (a2) and (a3) is 100% by mass).

  The radical polymerizable compound having a phenolic hydroxyl group that gives the structural unit (a2) is preferably α-methyl-p-hydroxystyrene.

  The photosensitive resin film of this invention is formed using the said radiation sensitive resin composition, and a film thickness is 1-50 micrometers, It is characterized by the above-mentioned. In addition, the cured film of the present invention is formed by photocuring the photosensitive resin film.

  The radiation-sensitive resin composition of the present invention and the photosensitive resin film formed using the composition can be developed with an alkaline aqueous solution, have a thickness of 20 μm or more and a resolution of 20 μm or less, Excellent adhesion to the substrate, shows wettability to the plating solution and plating solution resistance to the plating solution, can form good bumps or wiring by plating, and also has excellent peelability of the cured film from the substrate ing.

  Hereinafter, the radiation sensitive resin composition of the present invention will be described in detail.

[Radiation sensitive resin composition]
The radiation-sensitive resin composition of the present invention comprises a specific alkali-soluble copolymer (A), a compound (B) having an ethylenically unsaturated double bond, and a radiation-sensitive radical containing two or more specific compounds. And a polymerization initiator (C).

[Alkali-soluble copolymer (A)]
The alkali-soluble copolymer (A) used in the present invention is a structural unit (a1) derived from a radically polymerizable compound having a carboxyl group (hereinafter also referred to as “radical polymerizable compound (a1)”), a phenolic hydroxyl group. A structural unit (a2) derived from a radically polymerizable compound (hereinafter also referred to as “radical polymerizable compound (a2)”) and other radically polymerizable compound (hereinafter also referred to as “radical polymerizable compound (a3)”). .) Is included.

  When the total amount of the radical polymerizable compounds (a1), (a2) and (a3) is 100% by mass, the alkali-soluble copolymer (A) is usually 1 to 50 masses of the radical polymerizable compound (a1). %, Preferably 5 to 40% by weight, particularly preferably 5 to 25% by weight, of the radically polymerizable compound (a2) usually 1 to 50% by weight, preferably 5 to 40% by weight, particularly preferably 5 to 5% by weight. Radical copolymerization of the radically polymerizable compound (a3) in an amount of 25% by mass and usually in an amount of 5 to 98% by mass, preferably 20 to 90% by mass, particularly preferably 50 to 90% by mass. Can be obtained.

<Radically polymerizable compound having a carboxyl group (a1)>
The radically polymerizable compound (a1) having a carboxyl group used in the present invention can adjust the alkali solubility of the alkali-soluble copolymer (A).

  Examples of such radically polymerizable compound (a1) include acrylic acid, methacrylic acid, crotonic acid, 2-succinoloylethyl (meth) acrylate, 2-malenoylethyl (meth) acrylate, and 2-hexahydro. Phthaloylethyl (meth) acrylate, ω-carboxy-polycaprolactone monoacrylate (commercially available, for example, Aronix M-5300 manufactured by Toagosei Co., Ltd.), monohydroxyethyl acrylate phthalate (commercially available, for example, manufactured by the same company) Aronix M-5400), acrylic acid dimers (commercially available products such as Aronix M-5600 manufactured by the company, for example); carboxyls such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and other dicarboxylic acids (Meth) a having a group Such as acrylic acid derivatives. Among these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloylethyl methacrylate are preferable.

  The said radically polymerizable compound (a1) may be used individually by 1 type, or may be used in combination of 2 or more type. In addition, the content of the structural unit (a1) derived from the radical polymerizable compound (a1) in the alkali-soluble copolymer (A) is usually 1 to 50% by mass, preferably 5 to 40% by mass, particularly preferably. Is 5 to 25% by mass. If the content ratio of the structural unit (a1) is too small, the copolymer becomes difficult to dissolve in an alkaline developer, and thus a film residue may be generated after development and sufficient resolution may not be obtained. On the other hand, if the amount is too large, the solubility of the copolymer in the alkali developer may become too high, and dissolution of the exposed area, that is, film reduction may increase.

<Radically polymerizable compound having phenolic hydroxyl group (a2)>
Examples of the radical polymerizable compound (a2) having a phenolic hydroxyl group used in the present invention include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, α-methyl-p-hydroxystyrene, α-methyl- m-hydroxystyrene, α-methyl-o-hydroxystyrene, 2-allylphenol, 4-allylphenol, 2-allyl-6-methylphenol, 2-allyl-6-methoxyphenol, 4-allyl-2-methoxyphenol 4-allyl-2,6-dimethoxyphenol, 4-allyloxy-2-hydroxybenzophenone, and the like. Among these, p-hydroxystyrene and α-methyl-p-hydroxystyrene are preferable.

  The content ratio of the structural unit (a2) derived from the radical polymerizable compound (a2) in the alkali-soluble copolymer (A) is usually 1 to 50% by mass, preferably 5 to 40% by mass, particularly preferably 5 -25% by mass. If the amount of the structural unit (a2) is too small, the resolution of the radiation-sensitive resin composition is lowered. On the other hand, if the amount is too large, the molecular weight of the resulting copolymer is not sufficiently increased, and a coating film having a film thickness of 20 μm or more is formed. Becomes difficult.

  Moreover, as a compound which gives the structural unit (a2) derived from the radically polymerizable compound (a2), a radically polymerizable compound protected with a functional group which can be converted into a phenolic hydroxyl group after synthesizing a copolymer having alkali solubility (A2) A precursor can also be used.

  Examples of such a radical polymerizable compound (a2) precursor include p-acetoxystyrene, α-methyl-p-acetoxystyrene, p-benzyloxystyrene, p-tert-butoxystyrene, and p-tert-butoxycarbo. Nyloxy styrene, p-tert-butyldimethylsiloxy styrene, etc. are mentioned. The copolymer obtained using these can be easily converted into a copolymer containing the structural unit (a2) having a phenolic hydroxyl group by appropriate treatment, for example, hydrolysis using hydrochloric acid or the like.

<Other radical polymerizable compound (a3)>
The other radically polymerizable compound (a3) used in the present invention is mainly used for the purpose of appropriately controlling the mechanical properties of the alkali-soluble copolymer (A). Here, “other” means a radical polymerizable compound other than the above-described radical polymerizable compounds (a1) and (a2).

  Examples of such other radically polymerizable compound (a3) include (meth) acrylic acid alkyl esters, (meth) acrylic acid aryl esters, dicarboxylic acid diesters, nitrile group-containing polymerizable compounds, and amide bond-containing compounds. Examples thereof include polymerizable compounds, fatty acid vinyls, aromatic vinyls, chlorine-containing polymerizable compounds, and conjugated diolefins.

Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isopropyl (meth) acrylate, n-hexyl (Meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, methoxydipropylene glycol (Meth) acrylate, butoxy-dipropylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, etc. Alkyl acrylate esters;
Dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate, diethyl itaconate;
(Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate;
Aromatic vinyls such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene;
Nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile;
Amide bond-containing polymerizable compounds such as acrylamide and methacrylamide;
Fatty acid vinyls such as vinyl acetate;
Chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride;
Conjugated diolefins such as 1,3-butadiene, isoprene and 1,4-dimethylbutadiene can be used.

  The said radically polymerizable compound (a3) may be used individually by 1 type, or may be used in combination of 2 or more type. The content of the structural unit (a3) derived from the radical polymerizable compound (a3) in the alkali-soluble copolymer (A) is usually 5 to 98% by mass, preferably 20 to 90% by mass, and particularly preferably. It is 50-90 mass%.

<Polymerization solvent>
Examples of the polymerization solvent used in producing the alkali-soluble copolymer (A) include alcohols such as methanol, ethanol, ethylene glycol, diethylene glycol, and propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; Monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Alkyl ethers of polyhydric alcohols; alkyl ether acetates of polyhydric alcohols such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate; aromatic carbonization such as toluene and xylene Hydrogens; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol; ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, 2-hydroxy- Ethyl 2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2- Dorokishi 3-methylbutanoate, 3-methoxypropionate, methyl 3-methoxy propionate, ethyl 3-ethoxypropionate 3-ethoxypropionate methyl ethyl acetate, esters such as butyl acetate. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferred.

<Polymerization catalyst>
Moreover, as a polymerization catalyst in radical copolymerization, a normal radical polymerization initiator can be used, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile). ), 2,2′-azobis- (4-methoxy-2-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, tert-butylperoxypivalate, 1,1′-bis- (tert-butylperoxy) ) Organic peroxides such as cyclohexane and hydrogen peroxide. In addition, when using a peroxide for a radical polymerization initiator, it is good also as a redox type initiator combining a reducing agent.

<Molecular weight>
The molecular weight of the alkali-soluble copolymer (A) obtained by the above method is a polystyrene-equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC), and is usually 1,000 to 100,000, preferably 2,000. 50,000 to 50,000, more preferably 3,000 to 20,000.

[Compound (B) having an ethylenically unsaturated double bond]
The compound having at least one ethylenically unsaturated double bond used in the present invention (hereinafter also referred to as “ethylenically unsaturated compound (B)”) has at least one ethylenically unsaturated group in the molecule. In general, a (meth) acrylate compound having a (meth) acryloyl group as an ethylenically unsaturated group or a compound having a vinyl group is preferably used. The (meth) acrylate compound is classified into a monofunctional compound and a polyfunctional compound, and any compound can be used.

  Examples of such ethylenically unsaturated compounds (B) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, and ethyl. (Meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl ( Acrylate), decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecylamyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono ( (Meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxy Polyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, dicyclopentadienyl (meth) acrylate, dicyclo Pentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, N, N-dimethyl (meth) acrylamide, tert-octyl (meth) act Rilamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, dimethyl maleate, diethyl maleate, dimethyl fumarate, diethyl fumarate, 2- Hydroxyethyl methacrylate, ethylene glycol monomethyl ether (meth) acrylate, ethylene glycol monoethyl ether (meth) acrylate, glycerol (meth) acrylate, acrylic amide, methacrylic acid amide, (meth) acrylonitrile, methyl (meth) acrylate, ethyl ( Monofunctional monomers such as (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are exemplified.

  Examples of the polyfunctional compound include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth). ) Acrylate, 1,4-butanediol di (meth) acrylate, butylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris 2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, epoxy (meth) acrylate obtained by adding (meth) acrylic acid to diglycidyl ether of bisphenol A, bisphenol A di ( (Meth) acryloyloxyethyl ether, bisphenol A di (meth) acryloyloxyethyloxyethyl ether, bisphenol A di (meth) acryloyloxyloxymethyl ethyl ether, tetramethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, Such as pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. And the like.

  As the ethylenically unsaturated compound (B), a commercially available compound can be used as it is. Specific examples of commercially available compounds include Aronix M-210, M-309, M-310, M-315, M-320, M-321, M-400, and M-7100. M-8030, M-8060, M-8100, M-9050, M-240, M-240, M-245, M-6100, M-6200, M-6250, M-6300 , M-6400, M-6500 (above, manufactured by Toagosei Co., Ltd.), KAYARADR-551, R-712, TMPTA, HDDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620, R-604, DPCA-20, DPCA-30, DPCA-60, DPCA-120 (Nippon Kayaku Co., Ltd.), Biscote # 295, 300, 60, the 312, the 335HP, the 360, the GPT, said 3PA, the 400 (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

  The said ethylenically unsaturated compound (B) may be used individually by 1 type, or may be used in combination of 2 or more type. The ethylenically unsaturated compound is preferably 10 to 250 parts by weight, more preferably 20 to 200 parts by weight, and particularly preferably 25 to 150 parts by weight with respect to 100 parts by weight of the alkali-soluble copolymer (A). It can be used in parts. If the amount of the ethylenically unsaturated compound (B) is too small, the sensitivity at the time of exposure tends to decrease, and conversely, if it is too large, the compatibility with the copolymer (A) deteriorates and the storage stability decreases. Or it may be difficult to form a thick film of 20 μm or more.

[Radiation sensitive radical polymerization initiator (C)]
The radiation sensitive radical polymerization initiator (C) used in the present invention includes a compound (c1) represented by the following formula (1) and a compound (c2) represented by the following formula (2). Moreover, the said radiation sensitive radical polymerization initiator (C) may further contain the compound (c3) represented by following formula (3) with the said compounds (c1) and (c2) as needed.

In formula (1), R ¹ independently represents a hydrogen atom, a methyl group or an ethyl group, R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxyl group or a phenyl group, n Represents an integer of 1 to 5.

  In formula (2), Ph independently represents a phenyl group which may have a substituent, and X independently represents a hydrogen atom or halogen. As a substituent which the said phenyl group may have, a C1-C6 alkyl group or a C1-C6 alkoxyl group is mentioned, for example. When the phenyl group has a substituent, each of the plurality of phenyl groups may have 1 to 5 substituents independently.

In formula (3), R ⁴ is independently a hydrogen atom, halogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, —SR ⁷ (R ⁷ represents a methyl group or an ethyl group), a hydroxyl group, or —NR. ⁸ R ⁹ (R ⁸ and R ⁹ each independently represents a methyl group or an ethyl group, or R ⁸ and R ⁹ are bonded via an atom other than carbon to form a 4- to 8-membered cyclic structure. R ⁵ and R ⁶ each independently represents a hydrogen atom, a methyl group, an ethyl group or a phenyl group, and Y represents a hydroxyl group or —NR ¹⁰ R ¹¹ (R ¹⁰ and R ¹¹ Each independently represents a methyl group or an ethyl group, or R ¹⁰ and R ¹¹ may form a 4- to 8-membered cyclic structure via an atom other than carbon, and m represents The integer of 1-5 is represented.

  Examples of the compound (c1) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphosphine oxide, and the like. Is mentioned. Among these, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2,6-trimethylbenzoyldiphenylphosphine oxide are preferable. The said compound (c1) may be used individually by 1 type, or may be used in combination of 2 or more type.

  Examples of the compound (c2) include 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis ( 2,4-dichlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4-dimethylphenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2-methylphenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2, 2′-bisphenyl-4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetra Methoxyphenyl-1,2'-biimidazole, 2,2'-bis (2-c Rofeniru) -4,5,4 ', 5'-tetra-ethoxy-1,2'-bi imidazole. Among these, 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4-dichlorophenyl) ) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole is preferred. The said compound (c2) may be used individually by 1 type, or may be used in combination of 2 or more type.

As the compound (c3), for example,
2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1- (4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio ) Phenyl] -2-hydroxypropan-1-one, 2-methyl-1-phenyl-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- And butan-1-one. Among these, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane -1-one is preferred. The said compound (c3) may be used individually by 1 type, or may be used in combination of 2 or more type.

  A radiation-sensitive resin having high resolution by using the compound (c1) and the compound (c2) and, if necessary, the compound (c3) as the radiation-sensitive radical polymerization initiator (C). A composition is obtained.

  In the radiation-sensitive resin composition of the present invention, the total content of the compounds (c1) and (c2) and (c3) used as necessary contained in the radiation-sensitive radical polymerization initiator (C) is as follows: Preferably it is 1-30 mass parts with respect to 100 mass parts of said alkali-soluble copolymers (A), More preferably, it is 2-30 mass parts, Most preferably, it is 5-20 mass parts. If the total content of the compounds (c1), (c2) and (c3) used as necessary is too small, it is easily affected by radical deactivation (reduction in sensitivity) by oxygen, and if it is too much , There is a tendency for compatibility to deteriorate and storage stability to decrease.

  The radiation-sensitive radical polymerization initiator (C) may further contain a radiation-sensitive radical polymerization initiator other than the compounds (c1), (c2), and (c3) as necessary. Examples of radiation-sensitive radical polymerization initiators other than the compounds (c1), (c2) and (c3) include α-diketones such as benzyl and diacetyl; acyloins such as benzoin; benzoin methyl ether and benzoin ethyl ether Acyloin ethers such as benzoin isopropyl ether; thioxanthone, 2,4-diethylthioxanthone, thioxanthone-4-sulfonic acid, benzophenone, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) Benzophenones such as benzophenone; acetophenone, p-dimethylaminoacetophenone, α, α-dimethoxy-α-acetoxybenzophenone, α, α-dimethoxy-α-phenylacetophenone, p-methoxyacetophenone, etc. Acetophenones other than the compound (c3); quinones such as anthraquinone and 1,4-naphthoquinone; halogen compounds such as phenacyl chloride, tribromomethylphenylsulfone, tris (trichloromethyl) -s-triazine; di-tert- Examples thereof include peroxides such as butyl peroxide.

  Examples of commercially available products include Irgacure 184, 651, 500 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Lucyrin TPO (manufactured by BASF Co., Ltd.), Ubekrill P36 (manufactured by UCB Co., Ltd.), and the like. .

  In the composition of the present invention, if necessary, a compound having hydrogen donating properties such as mercaptobenzothioazole and mercaptobenzoxazole may be used in combination with the radiation-sensitive radical polymerization initiator (C). Moreover, you may use together the said radiation sensitive radical polymerization initiator (C) and a radiation sensitizer.

[Other ingredients]
In addition to the above-mentioned alkali-soluble copolymer (A), ethylenically unsaturated compound (B), and radiation-sensitive radical polymerization initiator (C), the radiation-sensitive resin composition of the present invention can be used as necessary. In addition, a solvent or various additives may be contained.

  As the organic solvent, one that can uniformly dissolve the alkali-soluble copolymer (A) and each component and does not react with each component is used. As such an organic solvent, those similar to the polymerization solvent used in producing the alkali-soluble copolymer (A) can be used, and further, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1 -High-boiling solvents such as nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate can also be added.

  Among these organic solvents, polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether and diethylene glycol monomethyl ether; ethyl cellosolve acetate, propylene Preferred are alkyl ether acetates of polyhydric alcohols such as glycol monomethyl ether acetate; esters such as ethyl 3-ethoxypropionate, methyl 3-methoxypropionate and ethyl 2-hydroxypropionate; ketones such as diacetone alcohol. is there. The amount of the solvent used can be determined as appropriate according to the application and application method.

  A thermal polymerization inhibitor can be added to the radiation-sensitive resin composition of the present invention. Examples of such thermal polymerization inhibitors include pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methylhydroquinone, amylquinone, amyloxyhydroquinone, n-butylphenol, phenol, hydroquinone mono Propyl ether, 4,4 ′-(1-methylethylidene) bis (2-methylphenol), 4,4 ′-(1-methylethylidene) bis (2,6-dimethylphenol), 4,4 ′-[1 -[4- (1- (4-hydroxyphenyl) -1-methylethyl) phenyl] ethylidene] bisphenol, 4,4 ', 4 "-ethylidene tris (2-methylphenol), 4,4', 4"- Ethylidene trisphenol, 1,1,3-tris (2,5-dimethyl-4-hydroxy And droxyphenyl) -3-phenylpropane. These can be preferably used in an amount of 5 parts by mass or less with respect to 100 parts by mass of the alkali-soluble copolymer (A).

  In the radiation sensitive resin composition of the present invention, a surfactant can be blended for the purpose of improving coating properties, antifoaming properties, leveling properties and the like. Examples of the surfactant include BM-1000, BM-1100 (above, manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (above, Dainippon Ink & Chemicals, Inc.), Fluorad FC-135, FC-170C, FC-430, FC-431 (manufactured by Sumitomo 3M Limited), Surflon S-112, S-113, S-131, S-141, S-145 (above, manufactured by Asahi Glass Co., Ltd.), SH-28PA, i-190, i-193, SZ-6032, SF-8428 (above, made by Toray Dow Corning Silicone Co., Ltd.), Ftergent FTX- Fluorine-type surfactant marketed with brand names, such as 218 (above, Neos Co., Ltd.), is mentioned. The blending amount of the surfactant is preferably 5 parts by mass or less with respect to 100 parts by mass of the alkali-soluble copolymer (A).

  In the radiation sensitive resin composition of the present invention, an adhesion aid can be used to improve the adhesion to the substrate. A functional silane coupling agent is effective as an adhesion aid. Here, the functional silane coupling agent means a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, or an epoxy group.

  Examples of such functional silane coupling agents include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ- Examples thereof include glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. The blending amount is preferably 20 parts by mass or less per 100 parts by mass of the alkali-soluble copolymer (A).

  In addition, the radiation-sensitive resin composition of the present invention includes acetic acid, propionic acid, n-butyric acid, iso-butyric acid, n-valeric acid, and iso-valeric acid in order to finely adjust the solubility in an alkali developer. Monocarboxylic acids such as benzoic acid and cinnamic acid; lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid Cinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, hydroxymonocarboxylic acids such as syringic acid; oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid , Isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, trimelli Polycarboxylic acids such as toic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; itaconic anhydride, succinic anhydride, citraconic anhydride, anhydrous Dodecenyl succinic acid, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride Acid anhydrides such as phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitic anhydride, and glycerin tris anhydrous trimellitate can also be added.

  Furthermore, a filler, a coloring agent, a viscosity modifier, etc. can also be added to the radiation sensitive resin composition of this invention as needed. Examples of the filler include silica, alumina, talc, bentonite, zirconium silicate, and powdered glass. Examples of colorants include extender pigments such as alumina white, clay, barium carbonate and barium sulfate; zinc white, lead white, yellow lead, red lead, ultramarine, bitumen, titanium oxide, zinc chromate, bengara, carbon black, etc. Inorganic pigments; organic pigments such as brilliant carmine 6B, permanent red 6B, permanent red R, benzidine yellow, phthalocyanine blue, and phthalocyanine; basic dyes such as magenta and rhodamine; direct dyes such as direct scarlet and direct orange; Examples include acid dyes such as roserine and methanyl yellow. Examples of the viscosity modifier include bentonite, silica gel, and aluminum powder. The compounding quantity of these additives should just be a range which does not impair the essential characteristic of a composition, Preferably, it is 50 mass% or less with respect to the composition obtained.

[Preparation of radiation-sensitive resin composition]
In preparing the radiation-sensitive resin composition of the present invention, when no filler and pigment are added, the above components (A), (B), (C), and other components as necessary Can be mixed and stirred in the usual manner. In the case of adding a filler and a pigment, these components may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three roll mill. Moreover, you may filter each component or the composition obtained using a mesh, a membrane filter, etc. further as needed.

[Usage of Radiation Sensitive Resin Composition]
The radiation-sensitive resin composition of the present invention can be used in the form of a liquid depending on the application, or by coating and drying a photosensitive resin composition on a flexible base film in advance (coating resin (photosensitive resin). Any method of a method (dry film method) in which a film) is formed and attached to a substrate can be used. However, in the case of the dry film method, the photosensitive resin film formed on the base film is preferably stored by laminating a cover film thereon when not in use. Hereinafter, the formation method of the coating film (photosensitive resin film) and the processing method of the coating film will be described in more detail.

<1. Method for forming coating film>
(1-1) When a liquid resin composition is used A desired coating film (photosensitive resin film) is formed by applying the liquid photosensitive resin composition on a predetermined substrate and removing the solvent by heating. can do. The photosensitive resin film of the present invention preferably has a thickness of 1 to 100 μm, more preferably 5 to 70 μm, and particularly preferably 10 to 50 μm.

  As a coating method on the substrate, a spin coating method, a roll coating method, a screen printing method, an applicator method and the like can be applied. In addition, although the drying conditions of a coating film change with kinds of each component in a composition, a mixture ratio, the thickness of a coating film, etc., it is 60-160 degreeC normally, Preferably it is 80-150 degreeC, and is 5 to 60 minutes. Degree. If the drying time is too short, the adhesion state during development will be poor, and if it is too long, the resolution may be lowered due to heat fogging.

  When a bump or wiring is formed by plating a substrate coated with the radiation sensitive resin composition of the present invention, the substrate surface must be coated with a metal. Examples of the method for coating the surface of the substrate with a metal include a method for depositing a metal and a method for sputtering, but the method for coating a metal used for the substrate used in the present invention is not particularly limited.

(1-2) When using a dry film When using the above-mentioned dry film, the cover film is peeled off and the photosensitive resin film is transferred to the substrate. As the transfer method, a thermocompression bonding method in which the substrate is heated in advance is preferable. When a dry film is used, wiring can be formed by plating using a metal-coated substrate as in the case of using it in a liquid state.

<2. Radiation irradiation method>
The obtained photosensitive resin film is irradiated with ultraviolet rays or visible rays having a wavelength of 300 to 500 nm through a photomask having a predetermined pattern, and for example, an exposed portion other than the bump pattern and the wiring pattern can be cured. Here, the radiation means ultraviolet rays, visible rays, far ultraviolet rays, X-rays, electron beams, and the like, and a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used as a light source. . The amount of radiation irradiation varies depending on the type of each component in the composition, the blending amount, the thickness of the coating film, and the like, but is, for example, 100 to 1500 mJ / cm ² when using a high-pressure mercury lamp.

<3. Development method>
As a developing method after radiation irradiation, an alkaline aqueous solution is used as a developing solution to dissolve and remove unnecessary non-exposed portions, leaving only exposed portions to obtain a cured film having a predetermined pattern. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, Dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3. [0] An aqueous solution of an alkali such as 5-nonane can be used. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution can also be used as a developer.

  The development time varies depending on the type of each component in the composition, the blending ratio, the thickness of the coating film, etc., but is usually 30 to 600 seconds, and the development method is a puddle method, a dipping method, a paddle method, a spray method. -Either method or shower developing method may be used. After the development, washing with running water is performed for 30 to 90 seconds and air-dried using an air gun or the like, or dried under heating such as a hot plate or oven.

<4. Post-processing>
The photosensitive resin film made of the composition of the present invention can be sufficiently cured only by the above-described radiation irradiation, but depending on the application, additional radiation irradiation (hereinafter referred to as “post-exposure”) or heating is further performed. Can be further cured.

The post-exposure can be performed by the same method as the above-mentioned radiation irradiation method, and the radiation irradiation amount is not particularly limited, but is preferably 100 to 2000 mJ / cm ² when using a high-pressure mercury lamp. Moreover, the method at the time of a heating uses heating apparatuses, such as a hotplate and an oven, predetermined | prescribed temperature, for example, 60-100 degreeC, for predetermined | prescribed time, for example, 5-30 minutes on a hotplate, and 5-5 in oven. What is necessary is just to heat-process for 60 minutes. By this post-treatment, a cured film having a predetermined pattern having even better characteristics can be obtained.

<5. Plating treatment>
The post-treated substrate is immersed in various plating solutions for electroplating, and plating is performed by setting the current value and the energization time so as to obtain a desired plating thickness.

<6. Peeling process>
For example, in order to peel the cured film of the present invention from a plated substrate, the substrate may be immersed in a stirring solution at 50 to 80 ° C. for 5 to 30 minutes. Examples of the stripping solution used here include an aqueous solution of a quaternary ammonium salt, a mixed solution of a quaternary ammonium salt, dimethyl sulfoxide and water, and an aqueous sodium hydroxide solution.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to this. Unless otherwise specified, parts are parts by mass, and% is mass%.

Synthesis Example 1 Synthesis of Alkali-Soluble Copolymer (A1) In a flask equipped with a nitrogen-substituted dry ice / methanol refluxer, 5.0 g of 2,2′-azobisisobutyronitrile (polymerization initiator) Then, 150 g of propylene glycol methyl ether acetate (solvent) was added and stirred until the polymerization initiator was dissolved. To this solution, 10 g of methacrylic acid, 15 g of α-methyl-p-hydroxystyrene, 20 g of isobornyl acrylate, 30 g of n-butyl acrylate, and 25 g of tricyclo (5.2.1.0 ^2,6 ) decanyl methacrylate are charged. Stir until the solids are completely dissolved. After complete dissolution, the temperature of the solution was raised to 80 ° C. and polymerization was carried out at this temperature for 7 hours. Then, the solution was heated to 100 ° C. and polymerized for 1 hour to obtain an alkali-soluble copolymer ( A reaction solution containing A1) was obtained.

<Synthesis Examples 2-5> Synthesis of Alkali-Soluble Copolymers (A2), (A3), (CA1) and (CA2) According to the composition shown in Table 1 below, synthesis examples except that the types and amounts of the compounds were changed. In the same manner as in Example 1, alkali-soluble copolymers (A2), (A3), (CA1) and (CA2) were synthesized. In addition, the symbol of the component in Table 1 is as follows.
a1-1: methacrylic acid a2-1: α-methyl-p-hydroxystyrene a3-1: isoboronyl acrylate a3-2: n-butyl acrylate a3-3: tricyclo (5.2.1.0 ^2,6 ) Decanyl methacrylate

[Example 1]
100 g of alkali-soluble copolymer (A1), 50 g of Toa Gosei Co., Ltd. “Aronix M8100” as the ethylenically unsaturated compound (B), 10 g of Toa Gosei Co., Ltd. “Aronix M320”, radiation sensitive radical polymerization initiator (C ) 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole 4 g, 2,4,6-trimethylbenzoyldiphenylphosphine oxide 4 g, interface Diglycerin ethylene oxide (average added mole number = 18) adduct perfluorononenyl ether (Ftergent FTX-218, manufactured by Neos Co., Ltd.) 0.3 g as an activator, and propylene glycol methyl ether acrylate 150 g as a solvent are mixed. Stir to prepare a homogeneous solution. This solution was filtered through a capsule filter having a pore diameter of 10 μm to obtain a radiation sensitive resin composition.

[Examples 2-7 and Comparative Examples 1-5]
A radiation sensitive resin composition was prepared in the same manner as in Example 1 except that the composition was changed to the composition shown in Table 2.

B1: Toa Gosei Co., Ltd. Aronix M8100 [Trifunctional or higher polyester acrylate]
B2: Toa Gosei Co., Ltd. Aronix M320 [Trimethylolpropane polyethylene oxide modified (n = 2) triacrylate]
B3: Toa Gosei Co., Ltd. Aronix M8060 [Trifunctional or higher polyester acrylate]
B4: Toa Gosei Co., Ltd. Aronix M315 [Trimethylolpropane polyethylene oxide modified (n = 1) triacrylate]
c1-1: 2,4,6-trimethylbenzoyldiphenylphosphine oxide c2-1: 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-bi Imidazole c2-2: 2,2′-bis (2,4-dichlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole c3-1: 2-methyl-1- [ 4- (Methylthio) phenyl] -2-morpholinopropan-1-one c3-2: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one c4-1: 4 , 4'-bis (diethylamino) benzophenone [Evaluation]
Using the radiation-sensitive resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 4, a resist pattern and a plated model are formed by the following method, and the characteristics of the photosensitive resin film and the cured film are evaluated. did. The results are shown in Table 3 and Table 4.

(1) Evaluation of bump formation performance <Pattern formation>
Each composition was applied onto a gold sputter substrate using a spin coater and then heated on a hot plate at 110 ° C. for 5 minutes to form a resin film having a thickness of 25 μm. Next, line / space (hereinafter referred to as "L / S") = 3/3, 4/4, 5/5, 6/6, 7/7, 8/8, 9/9, 10/10, 15/15 , 20/20, 25/25, 30/30 μm (design dimensions) through an ultrahigh pressure mercury lamp (OSRAM HBO, output 1,000 W) through a pattern mask, 300 to 1000 mJ / cm ² ultraviolet Irradiated with light. The exposure amount was confirmed with an illuminometer (a probe UV-42 (light receiver) connected to UV-M10 (illuminometer) manufactured by Oak Manufacturing Co., Ltd.)). After developing at room temperature using a 2.38 mass% tetramethylammonium hydroxide aqueous solution as a developing solution, it was washed with running water and blown with nitrogen to form a resist pattern. Hereinafter, the substrate on which the resist pattern is formed is referred to as “patterning substrate A”.

<Resolution evaluation>
The patterning substrate A was observed with a scanning electron microscope at 1000 times, and the resolution was measured. Here, the resolution means the mask design dimensions of the L / S pattern 3/3 μm, 4/4 μm, 5/5 μm, 6/6 μm, 7/7 μm, 8/8 μm, 9/9 μm, 10/10 μm, 15/15 μm. , 20/20 μm and 30/30 μm, the minimum mask dimension resolved without residual resist.

<Adhesion evaluation>
The adhesion to the substrate was evaluated by observing the cross section of the patterning substrate A with a scanning electron microscope at 1500 times. Specifically, “AA” is defined as the case where the resist is not lifted around the opening or the wafer edge, and “BB” is defined as the case where the resist is lifted or peeled off.

The patterning substrate A was subjected to an ashing treatment (output 100 W, oxygen flow rate 100 ml, treatment time 1 minute) by oxygen plasma as a pretreatment for electroplating to perform a hydrophilic treatment. Next, this substrate is subjected to electrolytic copper plating at 60 ° C., 0.5 A / dm ² , for 50 minutes or 75 minutes using Tempe Resist EX manufactured by Nippon Kogyo Kagaku Co., Ltd. as a plating solution to form a bump having a height of 15 μm. did. Thereafter, THB-S2 (manufactured by JSR, main component: dimethyl sulfoxide) was used as a peeling solution, and the resin film was peeled off by stirring for 10 minutes at 50 ° C. to obtain a substrate having a plated model. Hereinafter, the substrate having this plated model is referred to as “plated substrate A”.

  The peelability was evaluated by observing the plated substrate A with a scanning electron microscope at 1500 times. Specifically, the case where the residue was not observed was “AA”, and the case where the residue was observed was “BB”.

(2) Evaluation of high density wiring formation performance <Pattern formation>
Each composition was applied to a glass epoxy copper-clad substrate formed by laminating a copper foil having a thickness of 35 μm using a roll coater, and then heated at 75 ° C. for 45 minutes in a hot air oven to form a resin film having a thickness of 25 μm. Formed. Next, L / S = 3/3, 4/4, 5/5, 6/6, 7/7, 8/8, 9/9, 10/10, 15/15, 20/20, 25/25, Ultraviolet light of 300 to 1000 mJ / cm ² was irradiated using a super high pressure mercury lamp (HBO manufactured by OSRAM, output 1,000 W) through a pattern mask having 30/30 μm (design dimension). The exposure amount was confirmed with an illuminometer (a probe UV-42 (light receiver) connected to UV-M10 (illuminometer) manufactured by Oak Manufacturing Co., Ltd.)). After developing at room temperature using a 1% by mass aqueous sodium hydroxide solution as a developing solution, it was washed with running water and blown with nitrogen to form a resist pattern. Hereinafter, the substrate on which the resist pattern is formed is referred to as “patterning substrate B”.

<Formation of plated objects>
The patterning substrate B was subjected to electrolytic copper plating at 25 ° C. and 3 A / dm ² for 25 minutes using Microfab Cu200 manufactured by Nippon Electroplating Engineers Co., Ltd. as a plating solution to form a wiring having a height of 15 μm. Thereafter, a 3% aqueous sodium hydroxide solution was used as a peeling solution, and the resin film was peeled off by immersion for 10 minutes at 50 ° C. to obtain a substrate having a plated model. Hereinafter, the substrate having this plated model is referred to as “plated substrate B”.

<Evaluation of peelability>
The peelability was evaluated by observing the plated substrate B from which the resist cured film was peeled after plating with a scanning electron microscope at a magnification of 1500 times. Specifically, the case where the residue was not observed was “AA”, and the case where the residue was observed was “BB”.

<Resolution evaluation>
The patterning substrate was observed with a scanning electron microscope at 1000 times, and the resolution was measured. Here, the resolution means the mask design dimensions of the L / S pattern 3/3 μm, 4/4 μm, 5/5 μm, 6/6 μm, 7/7 μm, 8/8 μm, 9/9 μm, 10/10 μm, 15/15 μm. , 20/20 μm and 30/30 μm, the minimum mask dimension resolved without residual resist.

Claims (8)

(A) (a1) a structural unit derived from a radical polymerizable compound having a carboxyl group, (a2) a structural unit derived from a radical polymerizable compound having a phenolic hydroxyl group, and (a3) derived from another radical polymerizable compound An alkali-soluble copolymer containing structural units
(B) a compound having at least one ethylenically unsaturated double bond;
(C) (c1) a radiation-sensitive radical polymerization initiator containing a compound represented by the following formula (1) and (c2) a compound represented by the following formula (2): Resin composition.

Wherein (1), R ¹ is independently a hydrogen atom, a methyl group or an ethyl group, R ² and R ³ each independently represent an alkyl group or an alkoxyl group or a phenyl group having 1 to 6 carbon atoms, n represents an integer of 1 to 5. ]

[In formula (2), Ph independently represents a phenyl group which may have a substituent, and X independently represents a hydrogen atom or halogen. ] The radiation-sensitive resin composition according to claim 1, wherein the radiation-sensitive radical polymerization initiator (C) further comprises (c3) a compound represented by the following formula (3).

[In the formula (3), R ⁴ is independently a hydrogen atom, halogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, —SR ⁷ (R ⁷ represents a methyl group or an ethyl group), a hydroxyl group or — NR ⁸ R ⁹ (R ⁸ and R ⁹ each independently represents a methyl group or an ethyl group, or R ⁸ and R ⁹ are bonded via an atom other than carbon to form a 4- to 8-membered cyclic structure. May be formed)
R ⁵ and R ⁶ each independently represents a hydrogen atom, a methyl group, an ethyl group or a phenyl group,
Y is a hydroxyl group or —NR ¹⁰ R ¹¹ (R ¹⁰ and R ¹¹ each independently represents a methyl group or an ethyl group, or R ¹⁰ and R ¹¹ are bonded via an atom other than carbon to form 4 to 4 An 8-membered ring structure may be formed),
m represents an integer of 1 to 5. ]   The total content of the compounds (c1) and (c2) contained in the radiation-sensitive radical polymerization initiator (C) is 1 to 30 parts by mass with respect to 100 parts by mass of the alkali-soluble copolymer (A). The radiation sensitive resin composition of Claim 1 characterized by the above-mentioned.   The total content of the compounds (c1), (c2) and (c3) contained in the radiation-sensitive radical polymerization initiator (C) is 1 to 30 with respect to 100 parts by mass of the alkali-soluble copolymer (A). It is a mass part, The radiation sensitive resin composition of Claim 2 characterized by the above-mentioned.   The alkali-soluble copolymer (A) contains the structural unit (a1) in an amount of 1 to 50% by mass, the structural unit (a2) in an amount of 1 to 50% by mass, and the structural unit (a3). 5 to 98% by mass (however, the total amount of the structural units (a1), (a2) and (a3) is 100% by mass)). The radiation sensitive resin composition described in 1.   The radiation-sensitive resin composition according to any one of claims 1 to 5, wherein the radically polymerizable compound having a phenolic hydroxyl group that gives the structural unit (a2) is α-methyl-p-hydroxystyrene. object.   A photosensitive resin film formed using the radiation-sensitive resin composition according to claim 1 and having a thickness of 1 to 50 μm.   A cured film formed by photocuring the photosensitive resin film according to claim 7.