JP2010266768A - Photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating resist that sufficiently adheres to an electroless plating surface, facilitates removing of optically cured plating resist under an alkaline condition, does not re-adhere, and allows fine wiring. <P>SOLUTION: This photosensitive resin composition (Q) contains, as indispensable components, radical polymerizable compound (A) containing two or more organic groups (a) expressed by general formula (1) in each molecule, polyfunctional thiol compound (B), hydrophilic polymer (C), optical radical polymerization initiator (D), and acid generator (E). Pattern forming is enabled by light irradiation and alkaline developing. The part irradiated with light is made to be alkaline soluble by being heated at 100°C or higher. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition and a plating resist suitable for forming fine wiring on a printed wiring board using the same.

  In recent years, printed wiring boards used in electronic devices, communication devices, and the like have been increasingly demanded for high-density wiring and high processing speed. Accordingly, as a method of manufacturing a multilayer printed wiring board, a build-up manufacturing technique in which interlayer insulating layers are alternately stacked on a conductor layer of a circuit board has attracted attention.

  In general, as a wiring method of build-up method, for example, after electroless plating on the surface of the interlayer resin, a photosensitive resin plating resist is formed, a pattern is formed by light irradiation and alkali development, and electrolytic plating is performed. To form a conductor layer. Next, a semi-additive method is known in which after a plating resist is swelled and peeled off with a strong alkaline aqueous solution, an electroless plating in a non-wiring pattern portion is etched to form a wiring pattern.

  As the plating resist used in the semi-additive method, a negative photosensitive resin comprising a polyfunctional acrylic monomer, a carboxyl group-containing hydrophilic polymer, and a radical photopolymerization initiator is used. The light-irradiated portion is insolubilized by crosslinking and curing of the acrylic group by photoradical polymerization, and the unirradiated portion is formed into a pattern by dissolving in an alkali with a hydrophilic polymer. Further, the resin at the photocured portion after pattern formation is peeled off by swelling the resin portion with a strong alkaline aqueous solution and further spraying.

However, as the wiring pattern becomes finer, there is a problem that a defective wiring pattern due to peeling of the photocured plating resist between the wirings or reattachment of the peeled plating resist occurs.
Further, since a strong alkali treatment is required for peeling off the photocured plating resist, there is a problem that the insulating property of the interlayer insulating resin is lowered by the permeation of ions.

Furthermore, transmission loss due to unevenness on the surface of the wiring occurs due to high frequency accompanying the increase in the processing speed, so that the electroless plating formed on the surface of the interlayer resin becomes smooth. As the electroless plating surface becomes smoother, higher adhesion of the plating resist is required. However, the adhesion and peelability of the plating resist are contradictory and difficult to achieve at the same time.
Therefore, in order to form a fine wiring pattern, it is necessary to have a plating resist that adheres well to the electroless plating surface of the plating resist and that can easily remove the photocured plating resist under weak alkaline conditions and does not reattach. become.

As a method for easily removing the photocured plating resist, for example, a method for increasing the ratio of the carboxyl group of the hydrophilic resin to increase the hydrophilicity (Patent Document 1) has been proposed.
However, the method of increasing the hydrophilicity has a problem that the resolution is lowered because it swells even by alkali development after light irradiation.
In addition, as a method for preventing re-deposition of the plating resist, for example, a method of performing ultrasonic waves (Patent Document 2) has been proposed. However, the ultrasonic method has a problem that the fine wiring pattern is peeled off.
As a method for achieving both adhesion and peelability of the plating resist, for example, a method (Patent Document 3) or the like that makes it easier to permeate the alkali by heat treatment is proposed.
However, since the cross-linking cannot be completely decomposed by thermal decomposition and swells and peels, there is a problem in that it is difficult to peel off between wirings of 10 μm or less or inverted trapezoidal wiring, resulting in a pattern residue.

  Accordingly, there is a need for a plating resist that can adhere finely to the electroless plating surface of the plating resist, can easily remove the photocured plating resist under weak alkaline conditions, and can be finely wired without reattachment.

JP-A-9-325487 Japanese Patent Laid-Open No. 5-29210 Republished patent WO2005 / 022260

  It is an object of the present invention to provide a plating resist capable of fine wiring that has good adhesion to the electroless plating surface of the plating resist, is easy to remove the photocured plating resist under weak alkaline conditions, and does not reattach. To do.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the present invention provides a radical polymerizable compound (A), a polyfunctional thiol compound (B), a hydrophilic polymer containing two or more organic groups (a) represented by the following general formula (1) in one molecule. (C), a radical photopolymerization initiator (D) and an acid generator (E) are contained as essential components, and can be patterned by light irradiation and alkali development. A photosensitive resin composition (Q) characterized in that it is alkali-soluble by performing; and a plating resist (R) using this photosensitive resin composition (Q).

In Expression (1), R ¹ represents a hydrogen atom or a methyl group; ^{R 2} represents an alkyl group having 1 to 4 carbon atoms, n is an integer from 0 to 5. ]

Since the photosensitive resin composition (Q) of the present invention can be photocured by an ene-thiol reaction caused by ultraviolet irradiation and contains a thiol group, the adhesive property with a smooth electroless plating surface is also good. .
Furthermore, since the hydrophilic polymer (C) is contained, a pattern can be formed by alkali development.
In the present invention, the photocuring part is heated at 100 ° C. or higher, so that the acid generated from the acid generator causes the following general formula contained in the organic group (a) represented by the above chemical formula (2). The characteristic group (a1) represented by (2) is decomposed to generate carboxylic acid. In addition, since it is an addition reaction based on an ene-thiol reaction rather than a chain polymerization of double bonds, even if the decomposition reaction is incomplete, the crosslinked structure can be cut and alkali dissolution becomes possible. For this reason, when used as a plating resist, it has good adhesion to a smooth electroless plating surface, and it is easy to remove the photocured resin from the fine wiring part, so it does not reattach. A formable plating resist is provided.

[In formula (2), ^{R 2} is an alkyl group having 1 to 4 carbon atoms. ]

The present invention relates to a radically polymerizable compound (A) having a specific chemical structure, a polyfunctional thiol compound (B) containing two or more thiol groups in one molecule, a hydrophilic polymer (C), and a radical photopolymerization initiator. It is a photosensitive resin composition (Q) characterized by containing (D) and an acid generator (E) as essential components.
And the radically polymerizable compound (A) of this invention needs to contain 2 or more of organic groups (a) represented by following General formula (1) in 1 molecule.
The organic group (a) further contains a radical polymerizable double bond and a thermally decomposable characteristic group (a1) represented by the following general formula (2). The characteristic group (a1) is presumed to be decomposed into a compound having a carboxylic acid group, a hydroxyl group, and an aldehyde group by heat and an acid generator.

In Expression (1), R ¹ represents a hydrogen atom or a methyl group; ^{R 2} represents an alkyl group having 1 to 4 carbon atoms, n is an integer from 0 to 5. ]

[In formula (2), ^{R 2} is an alkyl group having 1 to 4 carbon atoms. ]

  The photosensitive resin composition (Q) of the present invention is subjected to alkali development after light irradiation, whereby the light-irradiated part is dissolved in alkali to form a pattern, and the photocured part crosslinked by light irradiation is 100 ° C. or higher. By performing the heat treatment, crosslinking is decomposed and becomes alkali-soluble.

  The radically polymerizable compound (A) of the present invention usually contains 2 to 10 organic groups (a) represented by the above general formula (1) in one molecule, preferably 8 or less, more preferably 6 Contains no more. If the number of organic groups (a) is 2 or more in one molecule, sufficient cross-linking is formed by light irradiation to obtain pattern strength, and if it is 10 or less, it is sufficiently decomposed and thermally dissolved by heat treatment.

  The radical polymerizable compound (A) may contain a radical polymerizable double bond other than the organic group (a) represented by the general formula (1), but from the viewpoint of thermal decomposition by heat treatment. It is preferably not included.

  When the radical polymerizable double bond other than the organic group (a) is not included, the crosslinking group of all radical reaction parts contains the characteristic group (a1) represented by the above general formula (2) which is thermally decomposable. Therefore, the crosslinked structure can be easily decomposed by thermal decomposition by heat treatment.

  Examples of the radical polymerizable double bond include a vinyl group (CH2 = CH-), a vinylidene group (CH2 = CH <), a vinylene group (-CH = CH-), and the like.

R ¹ of the organic group (a) of the radical polymerizable compound (A) of the present invention is a hydrogen atom or a methyl group, and a hydrogen atom is preferable from the viewpoint of photopolymerization reactivity.
R ² of the organic group (a) is a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group or an ethyl group is preferable from the viewpoint of heat decomposability of the characteristic group (a1) and ease of synthesis.
The n number in the general formula (1) of the organic group (a) is 0 to 5, and 0 or 1 is preferable from the viewpoint of photopolymerization reactivity.

The method for synthesizing the radically polymerizable compound (A) of the present invention is not particularly limited. For example, the carboxylic acid (I) represented by the following general formula (3) and two or more vinyl ether groups per molecule are used. Monomer containing (II) Monomer containing two or more 1-propenyl ether groups in one molecule (III) Monomer containing two or more 1-butylenyl ether groups in one molecule or one molecule Can be synthesized by addition reaction with any of the monomers containing two or more 1-pentenyl ether groups.
The other monomer to be subjected to addition reaction with the carboxylic acid (I) may be used alone or in combination of two or more.

[In Formula (3), R ¹ represents a hydrogen atom or a methyl group, n is an integer of 0 to 5. ]

  Of these, from the viewpoint of ease of production and availability, synthesis by addition reaction of carboxylic acid (I) and monomer (II) or monomer (III) in the above combination is preferred.

  Usually, a C = C double bond such as a carboxyl group in the carboxylic acid (I) and a vinyl ether group, a 1-propenyl ether group, a 1-butylenyl ether group, or a 1-pentenyl ether group under conditions of 0 ° C. to 150 ° C. Are synthesized by equimolar addition reaction.

As carboxylic acid (I), acrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-septenoic acid, methacrylic acid, 3-methyl-3-butenoic acid, 4-methyl-4-pentene Acid, 5-methyl-5-hexenoic acid, and 6-methyl-6-septenoic acid can be used.
Among these, acrylic acid, methacrylic acid, 3-butenoic acid, and 3-methyl-3-butenoic acid are preferable from the viewpoint of photopolymerization reactivity and ease of production, and more preferably acrylic acid, methacrylic acid, 3-butenoic acid.

  As the compound (II) containing a vinyl ether group, known compounds can be used, for example, ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,3-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether. , Trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetra Vinyl ether, sorbyl pentavinyl ether, Tylene glycol diethylene vinyl ether, triethylene glycol diethylene vinyl ether, ethylene glycol dipropylene vinyl ether, triethylene glycol diethylene vinyl ether, trimethylolpropane triethylene vinyl ether, trimethylolpropane diethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, pentaerythritol tetra Ethylene vinyl ether, reaction product of bisphenol A and chloromethyl vinyl ether, reaction product of bisphenol A and chloroethyl vinyl ether, reaction product of bisphenol A and acetylene, reaction product of hydroquinone and chloromethyl vinyl ether, hydroquinone and chloroethyl vinyl ether Reactants, reaction products of hydroquinone with acetylene, the reaction product of catechol and chloromethyl ether, there may be mentioned a reaction product of catechol and chloroethyl vinyl ether, but is not limited thereto.

  Known compounds can be used as the compound (III) containing a 1-propenyl ether group, such as ethylene glycol dipropenyl ether, triethylene glycol dipropenyl ether, 1,3-butanediol dipropenyl ether, tetramethylene glycol dipropenyl ether. , Neopentyl glycol dipropenyl ether, trimethylolpropane tripropenyl ether, trimethylol ethane tripropenyl ether, hexanediol dipropenyl ether, 1,4-cyclohexanediol dipropenyl ether, tetraethylene glycol dipropenyl ether, pentaerythritol dipropenyl ether , Pentaerythritol tripropenyl ether, pentaerythritol tetrapropenyl ether, sorbi Tetrapropyl ether, sorbyl pentapropenyl ether, ethylene glycol diethylene propenyl ether, triethylene glycol diethylene propenyl ether, ethylene glycol dipropylene propenyl ether, triethylene glycol diethylene propenyl ether, trimethylolpropane triethylenepropenyl ether, trimethylolpropane Diethylenepropenyl ether, pentaerythritol diethylenepropenyl ether, pentaerythritol triethylenepropenyl ether, pentaerythritol tetraethylenepropenyl ether, a reaction product of addition / rearrangement of bisphenol A and allyl chloride, reaction of addition / rearrangement of bisphenol A and allyl chloride Product, hydroquinone A reaction product of chloromethylpropenyl ether, a reaction product of hydroquinone and chloroethylpropenyl ether, a reaction product of catechol and chloromethylpropenyl ether, a reaction product of catechol and chloroethylpropenyl ether, etc. It is not something.

  The molecular weight of the radically polymerizable compound (A) of the present invention is usually 230 to 10,000, preferably 250 to 8,000, more preferably 300 to 6,000, from the viewpoint of developability. When the molecular weight exceeds 230, the resin hardness can be sufficiently exerted, and when the molecular weight is 10,000 or less, the developability can be satisfactorily exhibited.

  The content of the radically polymerizable compound (A) based on the weight of the solid content of the photosensitive resin composition (Q) is preferably 10 to 90% by weight, more preferably 15 to 85% by weight, particularly preferably 20 to 80%. % By weight. If it is 10% by weight or more, the photo-curing reactivity can be further improved, and if it is 90% by weight or less, the resolution can be further improved.

The photosensitive resin composition (Q) has a thiol group in one molecule in order to improve adhesion with a smooth electroless copper plating and to easily decompose the cross-linkage during heat treatment to make it alkaline soluble. The polyfunctional thiol compound (B) containing 2 or more is contained as an essential component.
By including the polyfunctional thiol compound (B), it becomes an addition reaction with a thiol group rather than a chain polymerization of radically polymerizable double bonds in the organic group (a). Even if the thermal decomposition reaction rate is not sufficient, the crosslinked structure can be easily decomposed.

  Examples of the polyfunctional thiol compound (B) include bifunctional thiol (B1), trifunctional thiol (B2), and tetrafunctional or higher thiol (B3). A polyfunctional thiol compound (B) may be used individually by 1 type, and may use 2 or more types together.

  Examples of the bifunctional thiol (B1) include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, 1,6- Hexanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 2,3-dimercapto-1-propanol, dithioerythritol, 2,3-dimercaptosuccinic acid, 1,2-benzenedithiol, 1,2- Benzenedimethanethiol, 1,3-benzenedithiol, 1,3-benzenedimethanethiol, 1,4-benzenedimethanethiol, 3,4-dimercaptotoluene, 4-chloro-1,3-benzenedithiol, 2 , 4,6-trimethyl-1,3-benzenedimethanethiol, 4,4'-thiodiphenol, Hexylamino-4,6-dimercapto-1,3,5-triazine, 2-diethylamino-4,6-dimercapto-1,3,5-triazine, 2-cyclohexylamino-4,6-dimercapto-1,3 5-triazine, 2-di-n-butylamino-4,6-dimercapto-1,3,5-triazine, ethylene glycol bis (3-mercaptopropionate), butanediol bisthioglycolate, ethylene glycol bisthio 2 such as glycolate, 2,5-dimercapto-1,3,4-thiadiazole, 2,2 ′-(ethylenedithio) diethanethiol, 2,2-bis (2-hydroxy-3-mercaptopropoxyphenylpropane) And compounds having one thiol group.

  Examples of the trifunctional thiol (B2) include 1,2,6-hexanetriol trithioglycolate, 1,3,5-trithiocyanuric acid, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris. Examples thereof include compounds having three thiol groups such as thioglycolate and tris [(3-mercaptopropionyloxy) -ethyl] isocyanurate.

  Examples of the tetrafunctional or higher thiol (B3) include four or more such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakisthioglycolate, dipentaerythritol hexakis (3-mercaptopropionate), and the like. The compound which has the thiol group of this is mentioned.

  Among these, from the viewpoint of photocurability and thermal decomposability, trifunctional thiol (B2) and tetrafunctional or higher thiol (B3) are preferable.

  The polyfunctional thiol compound (B) of the present invention usually contains 2 to 10 thiol groups in one molecule. Preferably it is 9 or less, more preferably 8 or less, particularly preferably 6 or less. If it is 2 or more, a sufficient cross-linked structure is formed by ene-thiol reaction with the double bond of the organic group (a) by light irradiation, and the strength of the pattern is obtained. The structure is easily decomposed and alkali solubility is obtained.

  The content of the polyfunctional thiol compound (B) based on the weight of the solid content of the photosensitive resin composition (Q) is usually 0.1 to 60% by weight, preferably 1 to 50% by weight, particularly preferably 2 to 40%. % By weight. If the polyfunctional thiol compound (B) is 0.1% by weight or more, the adhesiveness with the electroless copper plating is excellent, and if it is 60% by weight or less, the pattern strength of the cured product is excellent.

  The molar ratio (Am / Bm) of the number of moles (Am) of the organic group (a) in the radical polymerizable compound (A) of the present invention to the number of moles (Bm) of the thiol group in the polyfunctional thiol compound (B) is Usually, it is 0.5 to 1.5, preferably 0.6 to 1.4, and more preferably 0.7 to 1.3. If it is in the range of 0.5 to 1.5, a sufficient cross-linked structure is formed, the strength of the pattern is obtained, and the cross-linked structure is easily decomposed by heat treatment, so that alkali solubility is obtained.

The hydrophilicity index in the hydrophilic polymer (C) in the present invention is defined by HLB. Generally, the larger this value, the higher the hydrophilicity.
The preferred range of the HLB value of the hydrophilic polymer (C) varies depending on the resin skeleton of the hydrophilic polymer (C) (for example, vinyl resin, epoxy resin, polyester resin, etc.), preferably 4 to 19, and more preferably Preferably it is 5-18, Most preferably, it is 6-17. When it is 4 or more, the developing property is further improved when developing the photo spacer, and when it is 19 or less, the water resistance of the cured product is further improved.

In addition, HLB in this invention is an HLB value by the Oda method, is a hydrophilicity-hydrophobicity balance value, and can be calculated from the ratio of the organic value and inorganic value of an organic compound.
HLB ≒ 10 × Inorganic / Organic

  Here, the inorganic value and the organic value are described in the document “Surfactant Synthesis and Its Application” (published by Tsuji Shoten, Oda, Teramura), page 501; and the document “Introduction to New Surfactants” ( This is described in detail on page 198 of Takehiko Fujimoto, published by Sanyo Chemical Industries, Ltd.).

The hydrophilic polymer (C) preferably has a carboxyl group from the viewpoint of developability. The carboxyl group content is indicated by an acid value.
The acid value of the hydrophilic polymer (C) is preferably 10 to 500 mgKOH / g. If it is 10 mgKOH / g or more, the developability is more likely to be exhibited, and if it is 500 mgKOH / g or less, the water resistance of the cured product can be further improved.

The acid value of the hydrophilic polymer (C) in the present invention can be measured by an indicator titration method using an alkaline titration solution.
A specific method is as follows.
(I) About 1 g of a sample is precisely weighed and placed in an Erlenmeyer flask, and then a neutral methanol / acetone solution (a mixture of acetone and methanol at 1: 1 (volume ratio)) is added and dissolved.
(Ii) Add several drops of phenolphthalein indicator and titrate with 0.1 mol / L potassium hydroxide titration solution. The end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds.
(Iii) Determine using the following equation.
Acid value (KOHmg / g) = (A × f × 5.61) / S
Where, A: number of mL of 0.1 mol / L potassium hydroxide titration solution f: titer of 0.1 mol / L potassium hydroxide titration solution S: sampling amount (g)

  The number average molecular weight (hereinafter referred to as Mn) of the hydrophilic polymer (C) measured by gel permeation chromatography (GPC) is usually 2,000 from the viewpoint of hardness and developability when it becomes a cured product. And 100,000 or less, preferably 2,500 to 80,000, and more preferably 3,000 to 50,000. When Mn exceeds 2,000, the resin hardness can be sufficiently exerted, and when Mn is 100,000 or less, the developability can be satisfactorily exhibited.

Examples of the hydrophilic polymer (C) include a vinyl polymer (C1), an epoxy polymer, polyester, polyamide, polycarbonate, and polyurethane. A hydrophilic polymer (C) may be used by 1 type, and may use 2 or more types together.
Among these, the vinyl polymer (C1) is preferable from the viewpoint of the hardness of the obtained cured product and the ease of production.

  A preferable production method of the vinyl polymer (C1) includes a vinyl monomer (Ca) having a hydrophilic group (hereinafter sometimes simply referred to as (Ca)) and, if necessary, a hydrophobic group-containing vinyl monomer (Cb) (hereinafter, referred to as “Ca”). (Sometimes referred to as (Cb)).

Examples of the vinyl monomer (Ca) having a hydrophilic group include the following (Ca1) to (Ca3) vinyl monomers.
(Ca1) Carboxyl group-containing vinyl monomer:
Unsaturated monocarboxylic acids [such as (meth) acrylic acid, crotonic acid and cinnamic acid], unsaturated polyvalent (2-4 valent) carboxylic acids [such as (anhydrous) maleic acid, itaconic acid, fumaric acid and citraconic acid], Unsaturated polyvalent carboxylic acid alkyl (alkyl group having 1 to 10 carbon atoms) ester [maleic acid monoalkyl ester, fumaric acid monoalkyl ester, citraconic acid monoalkyl ester, etc.] and salts thereof [alkali metal salt (sodium salt) And potassium salts, etc.), alkaline earth metal salts (calcium salts and magnesium salts, etc.), amine salts and ammonium salts, etc.].
Among (Ca1), an unsaturated monocarboxylic acid is preferable from the viewpoint of hydrophilicity, and (meth) acrylic acid is more preferable.

(Ca2) hydroxyl group-containing vinyl monomer:
Hydroxyalkyl (meth) acrylate [2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, etc.], polyalkylene glycol mono (meth) acrylate [polyethylene glycol mono (meta ) Acrylate etc.], alkylol (meth) acrylamide [N-methylol (meth) acrylamide etc.], hydroxystyrene, 2-hydroxyethylpropenyl ether and the like.
Among (Ca2), hydroxyalkyl (meth) acrylate, particularly 2-hydroxyethyl (meth) acrylate is preferable from the viewpoint of alkali developability.

(Ca3) sulfonic acid group-containing vinyl monomer:
Examples thereof include vinyl sulfonic acid, (meth) allyl sulfonic acid, styrene sulfonic acid, α-methyl styrene sulfonic acid, 2- (meth) acryloylamido-2-methylpropane sulfonic acid, and salts thereof. Examples of the salt include alkali metal (sodium and potassium) salts, alkaline earth metal (calcium and magnesium) salts, primary to tertiary amine salts, ammonium salts and quaternary ammonium salts.

  Of these (Ca), (Ca1) and (Ca2) are preferable from the viewpoint of imparting sufficient developability, and (Ca1) is particularly preferable.

  Examples of the hydrophobic group-containing vinyl monomer (Cb) include the following nonionic monomers (Cb1) to (Cb3).

(Cb1) (meth) acrylic acid ester;
C1-C20 alkyl (meth) acrylate of an alkyl group [for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, etc.]; alicyclic group-containing (meth) acrylate [dicyclopentanyl (meth) acrylate, sidiclopentenyl (meth) acrylate, isobornyl (meth) acrylate, etc. ];

(Cb2) aromatic hydrocarbon monomer;
And hydrocarbon monomers having a styrene skeleton [for example, styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, and benzylstyrene] and vinylnaphthalene. It is done.

(Cb3) carboxylic acid vinyl ester;
Examples thereof include those having 4 to 50 carbon atoms, such as vinyl acetate, vinyl propionate and vinyl butyrate.

  Of these hydrophobic group-containing vinyl monomers (Cb), (Cb1) is preferred from the viewpoint of polymerizability.

  The charged monomer molar ratio of (Ca) / (Cb) in the hydrophilic polymer (C1) is usually from 10 to 100/0 to 90, and preferably from 10 to 80/20 to 90 from the viewpoint of photocuring reactivity and developability. More preferably, it is 25-85 / 15-75.

The hydrophilic polymer (C) may further contain an organic group (a) in the side chain for the purpose of further improving the photocuring reactivity. The organic group (a) in the hydrophilic polymer (C) is preferably contained in 1-10 molecules, more preferably 2-5 in one molecule.
If the number of organic groups (a) is one or more in one molecule, sufficient cross-linking is formed by light irradiation to obtain pattern strength. If the number of organic groups (a) is 10 or less, they are sufficiently decomposed and thermally dissolved by heat treatment.

  The content of the hydrophilic polymer (C) based on the weight of the solid content of the photosensitive resin composition (Q) is preferably 10 to 90% by weight, more preferably 15 to 85% by weight, particularly preferably 20 to 80% by weight. %. If it is 10% by weight or more, the alkali developability can be exhibited more satisfactorily, and if it is 90% by weight or less, the resolution can be exhibited more satisfactorily.

  In the photosensitive resin composition (Q), a radical bond polymerization initiator (D) is used to cause an ene-thiol reaction between the double bond in the organic group (a) and the thiol group in the polyfunctional thiol compound (B). Contains as an essential component.

Examples of the photo radical polymerization initiator (D) include benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, methyl benzoyl formate, isopropyl thioxanthone, 4,4-bis (dimethylamino) benzophenone, 3,3-dimethyl-4-methoxy-benzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, tert-butylanthraquinone, benzoin, benzoin methyl ether, benzoin ethyl ether, Benzoinpropyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-hydroxy-2-methylpropion Non, 4-isopropyl-2-hydroxy-2-methylpropiophenone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone, 2-chlorothioxanthone, diethylthioxanthone, isopropylthioxanthone , Diisopropylthioxanthone, Michler's ketone, benzyl-2,4,6- (trihalomethyl) triazine, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer, 9-phenylacridine, 1,7-bis (9 -Acridinyl) heptane, 1,5-bis (9-acridinyl) pentane, 1,3-bis (9-acridinyl) propane, dimethylbenzyl ketal, trimethylbenzoyldiphenylphosphine oxide, tribromomethylphenylsulfone and 2-ben Le 2-dimethylamino-1 (4-morpholinophenyl) - butan-1-one or the like.
The radical photopolymerization initiator (D) may be used alone or in combination of two or more.

  As the radical photopolymerization initiator (D), a commercially available product can be easily obtained. For example, Irgacure 907 is used as 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone. Examples of 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one include Irgacure 369 (manufactured by Ciba Specialty Chemicals).

  The content of the photo-radical polymerization initiator (D) based on the weight of the solid content of the photosensitive resin composition (Q) is preferably 0.001 to 10% by weight, more preferably 0.01 to 7% by weight, particularly Preferably it is 0.05-5 weight%. If it is 0.001% by weight or more, the photocuring reactivity can be exhibited more satisfactorily, and if it is 10% by weight or less, the resolution can be further improved.

  The photosensitive resin composition (Q) contains the acid generator (E) as an essential component in order to decompose the characteristic group (a1) by heat treatment.

Examples of the acid generator (E) include a water-insoluble photoacid generator (E1), a water-soluble photoacid generator (E2), and a thermal acid generator (E3).
Examples of the water-insoluble photoacid generator (E1) include the following sulfone compound (E11), sulfonic acid ester compound (E12), sulfonimide compound (E13), and disulfonyldiazomethane (E14).

Examples of the sulfone compound (E11) include phenacylphenylsulfone, 4-trisphenacylsulfone-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof.
Examples of the sulfonic acid ester compound (E12) include benzoin tosylate, pyrogallol tris trifluoromethane sulfonate, pyrogallol methane sulfonic acid triester, α-methylol benzoin tosylate, α-methylol benzoindodecyl sulfonate, and the like.

  Examples of the sulfonimide compound (E13) include N- (trifluoromethylsulfonyloxy) succinimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-di. Carboximide, N- (perfluorooctanesulfonyloxy) naphthylimide, N- (benzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (benzenesulfonyloxy) ) Bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide and N- (benzenesulfonyloxy) naphthylimide.

  Examples of the disulfonyldiazomethane compound (E14) include bis (trifluoromethylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (2,4-dimethylbenzenesulfonyl) diazomethane, bis And (1-methylethylsulfonyl) diazomethane and bis (1,4-dioxaspiro [4,5] decan-7-sulfonyl) diazomethane.

  Examples of the water-soluble photoacid generator (E2) include sulfonium salts [bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, allylsulfonium hexafluorophosphate salts, etc.], iodonium salts (diphenyliodonium hexafluoro). Phosphates, etc.), phosphonium salts (such as ethyltriphenylphosphonium tetrafluoroborate), diazonium salts (such as phenyldiazonium hexafluorophosphate), ammonium salts (such as 1-benzyl-2-cyanopyridinium hexafluorophosphate), and ferrocene [(2 , 4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe (II) hexafluorophosphate, etc.].

Examples of the thermal acid generator (E3) include diazonium salts (SI Schlesinger, Photogr. Sci. Eng., 18, 387 (1974), TS Bal et al, Polymer, 21, 423 (1980). )), Ammonium salts (U.S. Pat. Nos. 4,0690,05, 4,690,056, Reissue 27992, and JP-A-4-365049), phosphonium salts (DC Necker et al. , Macromolecules, 17, 2468 (1984), CS Wen et al, Teh, Proc. Conf. Rad, Curing ASIA, p478 Tokyo, Oct (1988), US Patent Nos. 4069055 and 4069056. ), Iodonium salt ( JV Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng.News, Nov. 28, p31 (1988), European Patent No. 104143, US Patent Nos. 3,39049, 410201. In the specification of JP-A-2-150848 and JP-A-2-296514), sulfonium salts (JV Crivello et al, Polymer J. 17, 73 (1985), JV Crivello). et al. J. Org. Chem., 43, 3055 (1978), WR Watt et al, J. Polymer Sci., Polymer Chem. Ed., 22, 1789 (1984), J. V. Crivello et. al, Polymer Bull. 14, 279 (1985), JV Crivello et al, Macromolecules, 14 (5), 1141 (1981), JV Crivel. Lo et al, J. Polymer Sci., Polymer Chem. Ed., 17 U.S. Pat. Nos. 4734444, 2833827, German Patent Nos. 2904626, 3604580, and 360481, a selenonium salt (JV Crivello et al, Macromolecules, 10 ( ), 1307 (1977), J. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979)), sulfonium salts (benzylmethyl P-hydroxyphenylsulfonium hexafluoroantimonate), and arsonium salts (C. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988)).
Examples of the counter anion of the onium salt include BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , C ₄ F ₉ SO ₃ ⁻ , C ₈ F ₁₇ SO ₃ ^— and CH ₃ SO ₃ ^— .

  Among these acid generators (E), the water-insoluble photoacid generator (E1) and the thermal acid generator (E3) are preferable from the viewpoint of compatibility with the photosensitive resin composition (Q). Yes, more preferably a thermal acid generator (E3).

The content of the acid generator (E) based on the weight of the solid content of the photosensitive resin composition (Q) is preferably 0.001 to 15% by weight, more preferably 0.01 to 10% by weight, particularly preferably. 0.05 to 7% by weight.
If it is 0.001% by weight or more, the decomposition reactivity during heating of the organic group (a) can be exhibited more favorably, and if it is 15% by weight or less, the physical properties of the cured product can be exhibited more favorably.

The photosensitive resin composition (Q) may further contain other components (F) as necessary.
As other components (F), inorganic fine particles (F1), sensitizers (F2), polymerization inhibitors (F3), and other additives (for example, inorganic pigments, silane coupling agents, dyes, fluorescent brighteners) , Yellowing inhibitors, antioxidants, antifoaming agents, etc.).

As the inorganic fine particles (F1), metal oxides and metal salts can be used.
Examples of the metal oxide include titanium oxide, silicon oxide, and aluminum oxide.
Examples of the metal salt include calcium carbonate and barium sulfate.
Of these, metal oxides are preferable from the viewpoint of heat resistance and chemical resistance, and silicon oxide and titanium oxide, and particularly silicon oxide are more preferable.
The inorganic fine particles have a volume average primary particle diameter of 1 to 200 nm, preferably from 1 to 150 nm, more preferably from 1 to 120 nm, and particularly preferably from 5 to 20 nm, from the viewpoint of transparency.

  The content of (F1) based on the weight of the solid content of the photosensitive resin composition (Q) is usually 0 to 50% by weight, preferably 1 to 45% by weight, particularly preferably 2 to 40% by weight. If it is 50% by weight or less, the developability can be further improved, and if it is 2 to 40% by weight, the heat resistance is particularly excellent.

  Examples of the sensitizer (F2) include nitro compounds (for example, anthraquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, benzanthrone, p, p′-tetramethyldiaminobenzophenone, carbonyl compounds such as chloranil, nitrobenzene, p -Dinitrobenzene and 2-nitrofluorene etc.), aromatic hydrocarbons (eg anthracene and chrysene etc.), sulfur compounds (eg diphenyl disulfide etc.) and nitrogen compounds (eg nitroaniline, 2-chloro-4-nitroaniline) , 5-nitro-2-aminotoluene, tetracyanoethylene and the like.

  The content of the sensitizer (F2) based on the weight of the radical photopolymerization initiator (D) is usually 0.1 to 100% by weight, preferably 0.5 to 80% by weight, particularly preferably 1 to 70% by weight. It is.

  There is no limitation in particular as a polymerization inhibitor (F3), What is used for normal reaction is used. Specifically, diphenylhydrazyl, tri-p-nitrophenylmethyl, N- (3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, p-benzoquinone, p-tert-butylcatechol, nitrobenzene, Examples include picric acid, dithiobenzoyl disulfide, and copper (II) chloride.

  The content of the polymerization inhibitor (F3) based on the weight of the solid content of the photosensitive resin composition (Q) is preferably 0 to 1.0% by weight, more preferably 0.01 to 0.5% by weight, particularly. Preferably it is 0.02 to 0.1 weight%.

As a method for forming the plating resist (R) of the present invention, a photosensitive resin composition (Q) is dissolved in a predetermined organic solvent, or dissolved and dispersed (only when inorganic fine particles (F1) are included). A method of forming a plating resist (R) by applying a resin varnish (QW) to a substrate using a known method such as curtain coating, roll coating, spray coating, or screen printing, and then drying the solvent by heating or hot air blowing, and A plating resist film (RF) obtained by applying a resin varnish (QW) to a support base film and drying the resin varnish (QW) on the support base film is applied to the substrate. Examples thereof include a method of forming a plating resist (R) by performing a pressure laminating step under heating conditions.
A preferred method is a method in which a plating resist film (RF) is pressure-laminated under heating conditions. This is preferable because the productivity of the printed wiring board is greatly improved.

The organic solvent for dissolving the photosensitive resin composition (Q) is not particularly limited as long as the resin composition can be dissolved and the resin solution can be adjusted to physical properties (viscosity, etc.) applicable to a film production apparatus. .
For example, known solvents such as N-methylpyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, acetone and xylene can be used. Of these solvents, those having a boiling point of 200 ° C. or less (toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, acetone and xylene) are preferable from the viewpoint of the drying temperature of the film, etc., alone or in combination of two or more. It can also be used.

  When the organic solvent is used, the amount of the solvent is not particularly limited, but is usually preferably 30 to 1,000% by weight, more preferably 40 based on the weight of the solid content of the photosensitive resin composition (Q). It is -900 weight%, Most preferably, it is 50-800 weight%.

  The resin varnish (QW) of the photosensitive resin composition (Q) can be obtained, for example, by mixing each component with a known mixing device such as a planetary mixer. The resin varnish (QW) is usually liquid at room temperature and has a viscosity of 0.1 to 10,000 mPa · s, preferably 1 to 8,000 mPa · s at 25 ° C.

  The drying conditions of the resin varnish (QW) vary depending on the solvent to be used, but it is preferably carried out at 50 to 200 ° C. for 2 to 30 minutes. The complex viscosity of the photosensitive resin composition (Q) after drying and the amount of residual solvent (Wt%) and the like are determined as appropriate.

As a substrate, an interlayer insulating resin layer is formed on a copper-clad laminate, an electroless plating or electrolytic plating layer is further formed on the surface of the interlayer insulating resin, and an electroless plating catalyst is applied to the surface of the interlayer insulating resin. Substrates are preferred.
Examples of the copper clad laminate include a glass epoxy, a metal plate, a polyester plate, a polyimide plate, a thermosetting polyphenylene ether plate, etc. bonded with a copper foil.

  Examples of the supporting base film include polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, and polycarbonate. The thickness of the base film is preferably 10 to 150 μm. The width of the base film is not particularly specified as long as it can enter the apparatus, but is preferably 30 to 300 cm.

  The base film may be subjected to a mold release treatment in addition to a mat treatment and a corona treatment. Since this resin composition exudes resin during lamination, if a support base portion having no resin is provided at both ends or one side of the roll at least 5 mm, it is easy to prevent the resin from adhering to the laminate portion and to peel off the support base film. There are advantages such as.

  When the plating resist film (RF) is pressure-laminated on the substrate under heating conditions, it is laminated while pressing and heating from the support base film side. Lamination may be performed under reduced pressure, in a batch system or a continuous system in a roll system, and it is preferable to laminate both surfaces simultaneously.

As for the lamination condition, the lamination temperature is usually 50 to 180 ° C, preferably 60 to 170 ° C, more preferably 70 to 150 ° C. If it is less than 50 ° C., it is difficult to transfer to the inner layer substrate.
The pressure of the laminate is usually 0.01 to 20 MPa, preferably 0.1 to 15 MPa. If it is less than 0.01 MPa, transfer to the inner layer substrate is difficult, and if it is higher than 20 MPa, the thickness of the plating resist (R) cannot be adjusted. The decompression condition is preferably 2.5 kPa or less.

After forming the plating resist (R) on the substrate, the wiring pattern-shaped groove is formed by performing the light irradiation of the wiring pattern shape and the step (I) of alkali development. Next, electroless plating or electrolytic plating is performed to form wiring in the groove portion.
Thereafter, the photocured plating resist (R) is dissolved and removed by performing a heating step of 100 ° C. or higher for decomposing the characteristic group (a1) portion in the organic group (a) and an alkali dissolution step (II), If necessary, the wiring can be formed by etching the electroless plating or the electrolytic plating layer.

Examples of the method of irradiating with light in the step (I) include a method of exposing the plating resist (R) with actinic rays through a photomask having a wiring pattern. The actinic ray used for light irradiation is not particularly limited as long as the photosensitive resin composition (Q) of the present invention can be cured.
Actinic rays include low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, xenon lamp, metal halogen lamp, electron beam irradiation device, X-ray irradiation device, laser (argon laser, dye laser, nitrogen laser, helium cadmium laser) Etc.). Of these, high pressure mercury lamps and ultrahigh pressure mercury lamps are preferred.

  Examples of the method of alkali development in step (I) include a method of dissolving and removing the wiring pattern shape using an alkali developer. The alkali developer is not particularly limited as long as the ultraviolet irradiation part of the photosensitive resin composition (Q) is not dissolved and the non-ultraviolet irradiation part can be dissolved.

  Examples of the alkali developer include a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, sodium hydrogen carbonate, and a tetramethylammonium salt aqueous solution. These alkaline developers may contain a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropyl alcohol, tetrahydrofuran and N-methylpyrrolidone.

  As a developing method, there are a dip method, a shower method, and a spray method using an alkaline developer, but the spray method is more preferable. The temperature of the developer is preferably 25 to 40 ° C. The development time is appropriately determined according to the thickness of the plating resist (R).

As temperature of the heating process which decomposes | disassembles the characteristic group (a1) part in the organic group (a) of process (II), it is 100-200 degreeC normally, Preferably it is 110-190 degreeC, More preferably, it is 120-180. ° C. If it is less than 100 degreeC, characteristic group (a1) cannot fully decompose | disassemble, but alkali solubility is insufficient, and when higher than 200 degreeC, there exists a problem that productivity of a printed wiring board falls.
The heating time is usually 2 to 120 minutes, preferably 3 to 90 minutes, and more preferably 3 to 90 minutes. If it is less than 2 minutes, it is difficult to control the time and temperature, and if it is more than 120 minutes, there is a problem that productivity of the printed wiring board is lowered.

Examples of the method of dissolving in alkali in the step (II) include a method of dissolving and removing using an aqueous alkali solution. Examples of the alkaline aqueous solution include a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, sodium hydrogen carbonate, and a tetramethylammonium salt aqueous solution. These alkaline aqueous solutions may contain a water-soluble organic solvent.
Examples of the water-soluble organic solvent include methanol, ethanol, isopropyl alcohol, tetrahydrofuran and N-methylpyrrolidone.
As a dissolution method, there are a dipping method, a shower method, and a spray method using an alkaline aqueous solution, and the spray method is more preferable. The temperature of the aqueous solution is preferably 25 to 40 ° C. The dissolution time is appropriately determined according to the thickness of the plating resist (R).

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

<Synthesis Example 1>
<Synthesis of Radical Polymerizable Compound (A-1)>
A three-necked flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser was charged with 196 parts of 1,4-cyclohexanedimethanol divinyl ether (manufactured by Nippon Carbide Industries Co., Ltd., “CHDVE”), and then acrylic. While gradually adding 144 parts of acid, the mixture was reacted at 50 ° C. for 12 hours to obtain a radically polymerizable compound (A-1) having two organic groups (a) essential in the present invention in the molecule.

<Synthesis Example 2>
<Synthesis of Radical Polymerizable Compound (A-2)>
A three-necked flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser was charged with 240 parts of pentaerythritol tetravinyl ether (manufactured by Nippon Carbide Industries Co., Ltd., “PEVE”) and 120 parts of methyl ethyl ketone at room temperature. Dissolved uniformly. Next, 344 parts of 3-butenoic acid (vinyl acetic acid) was gradually added, and after reacting at 75 ° C. for 18 hours, the solvent was removed under reduced pressure, whereby radical polymerization having four organic groups (a) in the molecule. Compound (A-2) was obtained.

<Synthesis Example 3>
<Synthesis of hydrophilic polymer (C-1)>
A three-necked flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser is charged with 60 parts of isobornyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate, 20 parts of methacrylic acid, and 150 parts of methyl ethyl ketone up to 80 ° C. Heated.
After substituting the gas phase part in the system with nitrogen, 55 parts of a solution prepared by dissolving 5 parts of AIBN prepared in advance in 50 parts of methyl ethyl ketone was dropped into Kolben at 80 ° C. over 10 minutes, and the same temperature. For 3 hours.
Thereafter, methylethylketone was removed under reduced pressure to obtain a hydrophilic polymer having a hydroxyl group and a carboxyl group (C-1: Mn: 21,000, SP value: 12.24, HLB value: 12.38, hydroxyl value: 86 mgKOH / g , Acid value: 138 mgKOH / g), a hydrophilic polymer (C-1) was obtained.

<Comparative Synthesis Example 1>
<Synthesis of Radical Polymerizable Compound (A′-1)>
In the same manner as in Synthesis Example 1 except that 126 parts of cyclohexyl vinyl ether (“CHVE” manufactured by Nippon Carbide Industries Co., Ltd.) was used instead of 196 parts of 1,4-cyclohexanedimethanol divinyl ether, an organic group (a) in the molecule was used. A radically polymerizable compound (A′-1) having only one was obtained.

<Example 1>
In a three-necked flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser, 40 parts of the hydrophilic polymer (C-1) synthesized in Synthesis Example 3 and 100 parts of methyl ethyl ketone were uniformly dissolved. Next, 30 parts of the radically polymerizable compound (A-1) synthesized in Synthesis Example 1 and pentaerythritol tetrakis- (3-mercaptopropionate) (manufactured by Sakai Chemical Industry Co., Ltd.) as the polyfunctional thiol compound (B-1) , “PEMP”), 20 parts, photopolymerization initiator (D-1) (manufactured by Ciba Specialty Chemicals, Inc., Irgacure 907), sulfonium salt (benzylmethyl) as thermal acid generator (E-1) 5 parts of P-hydroxyphenylsulfonium hexafluoroantimonate (manufactured by Sanshin Chemical Industry Co., Ltd., “Sun-Aid SI-100L”) was added and dissolved by stirring at 25 ° C. to obtain a photosensitive resin varnish.

  This photosensitive resin varnish was applied to a copper-clad laminate (“CCL-HL830” manufactured by Mitsubishi Gas Chemical Company, Inc.) having a surface roughness of 0.15 μm and subjected to microetching at a coating speed of 0.3 m / min. The whole surface was coated with a knife coater so that the thickness of the photosensitive resin layer after drying was 20 μm, and then dried at 70 ° C. for 3 minutes to form a plating resist.

  The formed plating resist is exposed to a wiring pattern with a projection type exposure apparatus (manufactured by Oak Manufacturing Co., Ltd., HMW-661F-01), and developed by spraying a 1% sodium carbonate aqueous solution at 30 ° C. for 90 seconds with spray. After air blowing, the product was dried at 60 ° C. for 20 minutes in a circulating dryer.

  Next, after electrolytic copper plating was performed to form a 13 μm conductor layer, heating was performed at 140 ° C. for 30 minutes in a circulating air dryer, and then immersed in a 1% aqueous sodium hydroxide solution at 30 ° C. for 3 minutes. Subsequently, after washing with water and air blowing, the printed wiring board (Z-1) was obtained by drying at 100 ° C. for 20 minutes in an air circulation dryer.

<Example 2>
Instead of the radical polymerizable compound (A-1), 25 parts of the radical polymerizable compound (A-2) synthesized in Synthesis Example 2, and trimethylolpropane tris (3- A printed wiring board (Z-2) was obtained in the same manner as in Example 1 except that 25 parts of (Mercaptopropionate) (“TMMP” manufactured by Sakai Chemical Industry Co., Ltd.) (B-2) was used. .

<Comparative Example 1>
A printed wiring board (Z′-1) was prepared in the same manner as in Example 1 except that the polyfunctional thiol (B-1) was not used and 30 parts of the radical polymerizable compound (A-1) was changed to 50 parts. Obtained.

<Comparative example 2>
A printed wiring board (Z'-2) was prepared in the same manner as in Example 2 except that the polyfunctional thiol (B-2) was not used and 25 parts of the radical polymerizable compound (A-2) was changed to 50 parts. Obtained.

<Comparative Example 3>
A printed wiring board (Z′-3) was prepared in the same manner as in Example 2 except that the thermal acid generator (E-1) was not used and 40 parts of the hydrophilic polymer (C-1) was changed to 45 parts. Obtained.

<Comparative example 4>
Without using a hydrophilic polymer, 45 parts of radically polymerizable compound (A-1) is 45 parts, 20 parts of polyfunctional thiol compound (B-1) is 40 parts, and acid generator (E-1) is 5 parts. A printed wiring board (Z′-4) was obtained in the same manner as in Example 1 except that 10 parts was changed to 10 parts.

<Comparative Example 5>
A printed wiring board (Z′-) was prepared in the same manner as in Example 1 except that the radical polymerizable compound (A′-1) synthesized in Comparative Synthesis Example 1 was used instead of the radical polymerizable compound (A-1). 5) was obtained.

<Comparative Example 6>
Radical polymerizable compound (A′-2) containing no organic group (a) instead of radical polymerizable compound (A-2) (“Neomer DA-600” manufactured by Sanyo Chemical Industries, Ltd.); Dipentaerythritol pentaacrylate And dipentaerythritol hexaacrylate) was used in the same manner as in Example 1 except that 25 parts were used to obtain a printed wiring board (Z′-6).

<Performance evaluation>
As the wiring pattern formability of the plating resist, from the obtained printed wiring boards (Z-1), (Z-2), and (Z′-1) to (Z′-6), resist pattern formability, heat treatment The behavior of the resist in the later alkali and the wiring pattern formability were evaluated by the following methods.

<Resist pattern formability>
After exposure of the formed plating resist, development of 1% sodium carbonate aqueous solution, and drying, peeling of the resist pattern having a width of 25 μm and 15 μm using a shape measuring microscope (VD-8550, manufactured by Keyence Corporation) Were observed under the conditions of a microscope magnification of 200, and evaluated according to the following criteria.
○: There is no peeling of wiring. ×: There is some peeling of wiring.

<Behavior of resist after heat treatment>
After heat-treating the resist after light irradiation, the behavior when immersed in a 1% aqueous sodium hydroxide solution was visually observed and evaluated according to the following criteria.
○: Resist dissolves Δ: Resist swells ×: Resist does not change

<Wiring pattern formability>
The printed wiring board after wiring formation was observed using a shape measuring microscope between 25 μm and 15 μm wide wiring under the condition of 200 times magnification of the microscope, and evaluated according to the following criteria.
○: No pattern defect (disconnection of wiring, short circuit between wirings) ×: Some pattern defect (disconnection of wiring, short circuit between wirings)

  Table 1 shows the characteristics and evaluation results of the photosensitive resins and printed wiring boards obtained in Examples and Comparative Examples.

As is apparent from Table 1, when the photosensitive resin compositions of Examples 1 and 2 of the present invention are used as a plating resist, a resist pattern formability of 15 μm or less is good even on a low-roughness copper surface, and plating is performed. Since the resist can be dissolved and removed later, it can be seen that a wiring having no defect can be formed even with a wiring of 15 μm or less.
On the other hand, Comparative Example 1 and Comparative Example 2 that do not contain a polyfunctional thiol (B) have poor resist pattern formability due to low adhesion to a low-roughness copper surface. It can be seen that the removability of the resist is poor and there is a problem in the wiring pattern formability.
Further, Comparative Example 3 which does not contain an acid generator (E) has a problem in wiring pattern formability due to poor resist removability between wiring because decomposition of crosslinking by heat treatment is insufficient and swelling peeling occurs. I understand.
It can be seen that Comparative Example 4 which does not contain the hydrophilic polymer (C) has a problem in resist pattern formability due to poor solubility in the alkaline aqueous solution of the non-irradiated portion.
In Comparative Example 5 using the radically polymerizable compound (A′-1) having only one organic group (a), the photocurability of the resist is poor and there is a problem in resist pattern formation, and the organic group (a It can be seen that Comparative Example 6 using the radical polymerizable compound (A′-2) without) has a problem in the wiring pattern formability because the crosslinking is not decomposed by the heat treatment.

  When the photosensitive resin composition of the present invention is used as a plating resist, it has excellent adhesion to the copper surface, and because it can be dissolved and removed by heat treatment of the photocured part, it is excellent in the removability of the plating resist between the fine wiring, Moreover, since there is no reattachment, it is suitable as a plating resist for forming a printed wiring board suitable for increasing the density and speed of conductor circuits.

Claims (6)

Radical polymerizable compound (A), polyfunctional thiol compound (B), hydrophilic polymer (C), photoradical containing two or more organic groups (a) represented by the following general formula (1) in one molecule A photosensitive resin composition (Q) comprising a polymerization initiator (D) and an acid generator (E) as essential components, and capable of forming a pattern by light irradiation and alkali development.

In Expression (1), R ¹ represents a hydrogen atom or a methyl group; ^{R 2} represents an alkyl group having 1 to 4 carbon atoms, n is an integer from 0 to 5. ]   The photosensitive resin composition (Q) according to claim 1, wherein the light-irradiated portion is subjected to a heat treatment at 100 ° C. or more to make it alkali-soluble.   The ratio Am / Bm of the number of moles (Am) of the organic group (a) of the radical polymerizable compound (A) to the number of moles (Bm) of the thiol group of the polyfunctional thiol compound (B) is 0.5 to 1. The photosensitive resin composition (Q) according to claim 1 or 2, which is 5.   The photosensitive resin composition (Q) according to any one of claims 1 to 3, wherein the polyfunctional thiol compound (B) contains 2 to 6 thiol groups in one molecule.   N in Formula (1) is 0 or 1, The photosensitive resin composition (Q) in any one of Claims 1-4.   The plating resist (R) using the photosensitive resin composition (Q) in any one of Claims 1-5.