WO2013172433A1 - Alkali-developable thermosetting resin composition, and printed wiring board - Google Patents

Abstract

　Provided are a printed wiring board and an alkali-developable thermosetting resin composition with which a pattern layer can be formed by developing, even when an inorganic filler is filled in to a high level. Furthermore, the aim of the present invention is to provide a printed wiring board and an alkali-developable thermosetting resin composition with which a pattern layer exhibiting superior cooling/heating cycle characteristics can be formed.　The alkali-developable thermosetting resin composition is characterized by containing an alkali-developable resin, a heat-reactive compound, an inorganic filler and a photobase-generating agent, and by using selective optical irradiation to cause an addition reaction between the alkali-developable resin and the heat-reactive compound in order to enable negative pattern formation by alkali development.

Description

Alkali development type thermosetting resin composition, printed wiring board

The present invention relates to an alkali development type thermosetting resin composition and a printed wiring board.

Recently, as a material for a solder resist for a printed wiring board or a flexible printed wiring board, an alkali development type photo-curable resin composition using an alkaline aqueous solution as a developing solution has become mainstream in consideration of environmental problems. As such an alkali-developable photocurable resin composition, as shown in Patent Documents 1 and 2, an epoxy acrylate-modified resin (hereinafter, abbreviated as epoxy acrylate) derived by modification of an epoxy resin may be used. ) Is generally used.

As a method for forming a solder resist using such a photocurable resin composition, a photocurable resin composition is applied to a substrate and dried to form a resin layer, and the resin layer is patterned. There is a method of forming a predetermined pattern by developing with an alkaline developer after light irradiation.

Also, printed wiring boards and flexible printed wiring boards are mounted and used in various devices. For this reason, it is required to have resistance against abrupt changes in the environment such as temperature. Therefore, solder resists are also required to have high temperature change resistance, but when the difference in coefficient of linear expansion (CTE) between the thermosetting resin and the base material, such as base material, copper, or underfill is large, TCT There is a problem that cracks occur in the resist in the (thermal cycle test).

On the other hand, in recent years, the CTE of the thermosetting resin is matched with the CTE of the material of the peripheral member. For example, it is common to suppress cure shrinkage by reducing CTE by highly filling an inorganic filler in a thermosetting resin.

JP 61-243869 (Claims) Japanese Patent Laid-Open No. 3-250012 (Claims)

However, when the thermosetting resin composition is highly filled with an inorganic filler, light is prevented from penetrating deeply. In this case, there is a problem that it is difficult to form a pattern layer because resolution cannot be obtained.

Therefore, an object of the present invention is to provide an alkali development type thermosetting resin composition and a printed wiring board capable of forming a pattern layer by development even when highly filled with an inorganic filler. A further object of the present invention is to provide an alkali development type thermosetting resin composition and a printed wiring board capable of forming a pattern layer having excellent thermal cycle characteristics.

As a result of intensive studies to solve the above-described problems, the present inventors have found that the above-described problems can be solved with the following configuration, and have completed the present invention.

That is, the alkali-developable thermosetting resin composition of the present invention contains an alkali-developable resin, a heat-reactive compound, an inorganic filler, and a photobase generator. An addition reaction between the resin and the heat-reactive compound makes it possible to form a negative pattern by alkali development.

In the alkali development type thermosetting resin composition of the present invention, the inorganic filler preferably has an average particle size of 1 μm or less.

In addition, the alkali development type thermosetting resin composition of the present invention preferably has a refractive index difference of 0.3 or less between the inorganic filler and the resin.

In the alkali development type thermosetting resin composition of the present invention, the refractive index of the inorganic filler is preferably 1.45 or more and 1.65 or less.

In addition, the alkali development type thermosetting resin composition of the present invention generates an exothermic peak in DSC measurement by light irradiation, or starts heat generation in DSC measurement of the alkali development type thermosetting resin composition irradiated with light. The temperature is lower than the heat generation start temperature in the DSC measurement of the unirradiated alkali development type thermosetting resin composition, or the heat generation peak temperature in the DSC measurement of the light irradiated alkali development type thermosetting resin composition is It is preferable that the temperature is lower than the exothermic peak temperature in DSC measurement of the unirradiated alkali development type thermosetting resin composition.

According to the present invention, an alkali development type thermosetting resin composition and a printed wiring board capable of forming a pattern layer by development can be provided. Furthermore, according to the present invention, it is possible to provide an alkali development type thermosetting resin composition and a printed wiring board capable of forming a pattern layer having excellent curability and thermal cycle characteristics.

FIG. 1 is a schematic view showing an example of a pattern forming method using the alkali development type thermosetting resin composition of the present invention. FIG. 2 is a diagram showing a DSC chart for the resin layer made of the alkali development type thermosetting resin composition of Example 1 of the present invention. FIG. 3 is a cross-sectional view of a double-sided printed wiring board for explaining the evaluation of a dent on the through hole.

The alkali developing type thermosetting resin composition of the present invention (hereinafter sometimes abbreviated as “thermosetting resin composition”) includes an alkali developing resin, a thermoreactive compound, an inorganic filler, and It contains a photobase generator, and is characterized in that a negative pattern can be formed by alkali development by an addition reaction between an alkali-developable resin and a heat-reactive compound by selective light irradiation. Here, pattern formation means forming a patterned cured product, that is, a pattern layer.
In the resin layer made of the thermosetting resin composition, a base is generated on the surface by light irradiation. Then, it is considered that the photobase generator is destabilized by the generated base, and further the base chemically grows deeply. Here, while the base acts as a catalyst for the addition reaction between the alkali-developable resin and the heat-reactive compound, the addition reaction proceeds to the deep part, so that the resin layer is cured to the deep part in the light irradiation part.
Therefore, even when the inorganic filler is highly filled, the pattern layer can be easily formed by removing the non-irradiated portion by performing alkali development after irradiating the thermosetting resin composition in a pattern. it can.
In addition, since the thermosetting resin composition of the present invention cures by an addition reaction between the alkali-developable resin and the thermoreactive compound, it is possible to obtain a pattern layer with less strain and shrinkage than the photocurable resin composition. it can.
The thermosetting resin composition may be a composition that does not cure even when heated in an unirradiated state and that can be cured by heat only after irradiation with light.

The thermosetting resin composition of the present invention generates a heat generation peak in DSC measurement by light irradiation, or the heat generation start temperature in DSC measurement of the light-cured thermosetting resin composition is an unirradiated thermosetting resin. The exothermic peak temperature in the DSC measurement of the uncured thermosetting resin composition is lower than the exothermic peak temperature in the DSC measurement of the thermosetting resin composition that is lower than the exothermic start temperature in the DSC measurement of the composition or is irradiated with light. Is also preferably low.
In addition, the thermosetting resin composition of the present invention is also referred to as a temperature difference (ΔT start) of the heat generation starting temperature in DSC measurement between the light-irradiated thermosetting resin composition and the non-irradiated thermosetting resin composition. ) Or the exothermic peak temperature difference (also referred to as ΔT peak) is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, and even more preferably 30 ° C. or higher.
Here, ΔT start is a thermosetting resin composition having the same composition, one is irradiated with light, and the other is not irradiated with light, and the DSC (Differential Scanning Calorimetry) is left as it is. Each measurement is performed, and refers to the temperature difference between the heat generation start temperature indicating the start of the curing reaction of the resin composition irradiated with light and the heat generation start temperature of the unirradiated resin composition. ΔT peak refers to the temperature difference between the exothermic peak temperatures of the resin composition irradiated and unirradiated when DSC measurement is similarly performed.
In addition, the irradiation amount in the DSC measurement of the thermosetting resin composition irradiated with light increases the irradiation amount, and the exothermic peak temperature shift due to light irradiation of the thermosetting resin composition does not occur (saturation). is there.
When ΔT start or ΔT peak is 10 ° C. or higher, the occurrence of so-called fogging in which the unirradiated part remains due to alkali development and so-called biting in which the light-irradiated part is removed by alkali development is suppressed. be able to. Further, when ΔT start or ΔT peak is 10 ° C. or more, it is possible to widen the range of heating temperatures that can be taken in the heating step (B1) described later.

Hereinafter, each component of the thermosetting resin composition will be described in detail.

[Alkali developable resin]
The alkali-developable resin is a resin that contains one or more functional groups among phenolic hydroxyl groups, thiol groups, and carboxyl groups and that can be developed with an alkaline solution, preferably a compound having two or more phenolic hydroxyl groups, carboxyl Examples thereof include a group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups.

Examples of the compound having two or more phenolic hydroxyl groups include phenol novolac resin, alkylphenol volac resin, bisphenol A novolac resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene modified phenol resin, polyvinylphenols, bisphenol F, Examples thereof include known and commonly used phenol resins such as bisphenol S-type phenol resin, poly-p-hydroxystyrene, a condensate of naphthol and aldehydes, and a condensate of dihydroxynaphthalene and aldehydes.
In addition, as a phenol resin, a compound having a biphenyl skeleton or a phenylene skeleton, or both, and as a phenolic hydroxyl group-containing compound, phenol, orthocresol, paracresol, metacresol, 2,3-xylenol, 2,4- Xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, phloroglucinol You may use the phenol resin which synthesize | combined using these and which have various frame | skeletons.
These may be used alone or in combination of two or more.

As the carboxyl group-containing resin, a known resin containing a carboxyl group can be used. Due to the presence of the carboxyl group, the resin composition can be made alkali developable. In addition to the carboxyl group, a compound having an ethylenically unsaturated bond in the molecule may be used, but in the present invention, as the carboxyl group-containing resin, for example, ethylenically unsaturated as shown in (1) below. It is preferable to use only a carboxyl group-containing resin having no double bond.

Specific examples of the carboxyl group-containing resin that can be used in the present invention include the compounds listed below (any of oligomers and polymers).

(1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene. The lower alkyl refers to an alkyl group having 1 to 5 carbon atoms.

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

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

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

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

(6) During the synthesis of the resin of (2) or (4) above, one isocyanate group and one or more (meth) acryloyl groups are present in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. The carboxyl group-containing urethane resin which added the compound which has and was terminally (meth) acrylated.

(7) An unsaturated monocarboxylic acid such as (meth) acrylic acid is reacted with the polyfunctional (solid) epoxy resin as described above, and phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride is added to the hydroxyl group present in the side chain. A carboxyl group-containing resin to which a dibasic acid anhydride such as an acid is added.
(8) A dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride is reacted with a saturated monocarboxylic acid on the polyfunctional (solid) epoxy resin as described above, and the hydroxyl group present in the side chain. A carboxyl group-containing resin to which is added.

(9) A carboxyl obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin and adding a dibasic acid anhydride to the resulting hydroxyl group Group-containing resin.

(10) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin as described later with a dicarboxylic acid and adding a dibasic acid anhydride to the resulting primary hydroxyl group.

(11) A carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide. .

(12) A reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide is allowed to react with a saturated monocarboxylic acid. A carboxyl group-containing resin obtained by reacting a basic acid anhydride.

(13) Reaction product obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with a product.

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

(15) A carboxyl group obtained by reacting a polybasic acid anhydride with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. Containing resin.

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

(17) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and a saturated monocarboxylic acid React with acid and react with polybasic acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid etc. to the alcoholic hydroxyl group of the resulting reaction product Carboxyl group-containing resin obtained by making it.

(18) reacting an epoxy compound having a plurality of epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol; Carboxyl groups obtained by reacting polybasic acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid with the alcoholic hydroxyl group of the obtained reaction product Containing resin.

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

(20) One epoxy group and one or more (meth) acryloyl groups in the molecule of glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, etc., in addition to the resin of any one of (1) to (19) above A carboxyl group-containing resin formed by adding a group-containing compound.

Such an alkali-developable resin has a large number of carboxyl groups, hydroxyl groups, and the like in the side chain of the backbone polymer, so that development with an alkaline aqueous solution becomes possible.
The hydroxyl group equivalent or carboxyl group equivalent of the carboxyl group-containing resin is 80 to 900 g / eq. And more preferably 100 to 700 g / eq. It is. Hydroxyl group equivalent or carboxyl group equivalent is 900 g / eq. If it exceeds 1, the adhesion of the pattern layer may not be obtained, or alkali development may be difficult. On the other hand, the hydroxyl group equivalent or the carboxyl group equivalent is 80 g / eq. In the case of less than, because the dissolution of the light irradiation part by the developer proceeds, the line becomes thinner than necessary, or in some cases, the light irradiation part and the unirradiated part are dissolved and peeled off with the developer, This is not preferable because it may be difficult to draw a normal resist pattern. Further, it is preferable that the carboxyl group equivalent or the phenol group equivalent is large because development is possible even when the content of the alkali-developable resin is small.

The weight average molecular weight of the alkali-developable resin used in the present invention varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. If the weight average molecular weight is less than 2,000, tack-free performance may be inferior, the moisture resistance of the resin layer after light irradiation may be poor, film thickness may be reduced during development, and resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

In this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

Examples of the compound having a thiol group include trimethylolpropane tristhiopropionate, pentaerythritol tetrakisthiopropionate, ethylene glycol bisthioglycolate, 1,4-butanediol bisthioglycolate, trimethylolpropane tris. Thioglycolate, pentaerythritol tetrakisthioglycolate, di (2-mercaptoethyl) ether, 1,4-butanedithiol, 1,3,5-trimercaptomethylbenzene, 1,3,5-trimercaptomethyl-2 , 4,6-trimethylbenzene, terminal thiol group-containing polyether, terminal thiol group-containing polythioether, thiol compound obtained by reaction of epoxy compound with hydrogen sulfide, and reaction of polythiol compound with epoxy compound. Thiol compounds having a resultant terminal thiol group.

The alkali developable resin is preferably a carboxyl group-containing resin or a compound having a phenolic hydroxyl group. The alkali-developable resin is preferably non-photosensitive without a photocurable structure such as epoxy acrylate. Such a non-photosensitive alkali-developable resin does not have an ester bond derived from epoxy acrylate, and therefore has high resistance to desmear liquid. Therefore, a pattern layer having excellent curing characteristics can be formed. Moreover, since it does not have a photocurable structure, curing shrinkage can be suppressed.
When the alkali-developable resin is a carboxyl group-containing resin, development can be performed with a weak alkaline aqueous solution as compared with the case of a phenolic resin. Examples of the weak alkaline aqueous solution include those in which sodium carbonate or the like is dissolved. By developing with weak alkaline aqueous solution, it can suppress that a light irradiation part will be developed. Moreover, the light irradiation time in a process (B) and the heating time in a process (B1) can be shortened.

[Heat-reactive compound]
The thermoreactive compound is a resin having a functional group that can be cured by heat. An epoxy resin, a polyfunctional oxetane compound, etc. are mentioned.

The epoxy resin is a resin having an epoxy group, and any known one can be used. Examples thereof include a bifunctional epoxy resin having two epoxy groups in the molecule, and a polyfunctional epoxy resin having many epoxy groups in the molecule. In addition, a hydrogenated bifunctional epoxy compound may be used.

Polyfunctional epoxy compounds include bisphenol A type epoxy resin, brominated epoxy resin, novolac type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, alicyclic ring Epoxy resin, trihydroxyphenylmethane type epoxy resin, bixylenol type or biphenol type epoxy resin or mixtures thereof, bisphenol S type epoxy resin, bisphenol A novolac type epoxy resin, tetraphenylolethane type epoxy resin, heterocyclic epoxy Resin, diglycidyl phthalate resin, tetraglycidyl xylenoyl ethane resin, naphthalene group-containing epoxy resin, epoxy resin having dicyclopentadiene skeleton, glycidyl methacrylate Acrylate copolymer epoxy resins, copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, and a CTBN modified epoxy resin.

Other liquid bifunctional epoxy resins include vinylcyclohexene diepoxide, (3 ′, 4′-epoxycyclohexylmethyl) -3,4-epoxycyclohexanecarboxylate, (3 ′, 4′-epoxy-6′-methyl) And alicyclic epoxy resins such as (cyclohexylmethyl) -3,4-epoxy-6-methylcyclohexanecarboxylate. A naphthalene group-containing epoxy resin is preferable because it can suppress the thermal expansion of the cured product.

The above epoxy resins may be used alone or in combination of two or more.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-methyl -3-Oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) In addition to polyfunctional oxetanes such as methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol and novolak resin, Poly (p-hydroxystyrene), cardo-type bisphenol Le ethers, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.
Here, it is preferable that the heat-reactive compound has a benzene skeleton because heat resistance is improved. Moreover, when a thermosetting resin composition contains a white pigment, it is preferable that a thermoreactive compound is an alicyclic skeleton. Thereby, photoreactivity can be improved.

The blending amount of the heat-reactive compound is preferably such that the equivalent ratio with the alkali-developable resin (heat-reactive group: alkali-developable group) is 1: 0.1 to 1:10, and 1: 0 More preferably, it is 2 to 1: 5. When the ratio is within such a range, the development is good.

[Photobase generator]
One or more photobase generators can function as a catalyst for the addition reaction of the above-mentioned thermoreactive compound when the molecular structure is changed by irradiation with light such as ultraviolet rays or visible light, or when the molecule is cleaved. It is a compound that produces a basic substance. Examples of basic substances include secondary amines and tertiary amines.
Examples of photobase generators include α-aminoacetophenone compounds, oxime ester compounds, acyloxyimino groups, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzyl carbamate groups, alkoxybenzyl carbamates. And compounds having a substituent such as a group.

The α-aminoacetophenone compound has a benzoin ether bond in the molecule, and when irradiated with light, cleavage occurs in the molecule to produce a basic substance (amine) that exhibits a curing catalytic action. Specific examples of α-aminoacetophenone compounds include (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane (Irgacure 369, trade name, manufactured by BASF Japan Ltd.) and 4- (methylthiobenzoyl) -1-methyl. -1-morpholinoethane (Irgacure 907, trade name, manufactured by BASF Japan Ltd.), 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl]- A commercially available compound such as 1-butanone (Irgacure 379, trade name, manufactured by BASF Japan Ltd.) or a solution thereof can be used.

As the oxime ester compound, any compound that generates a basic substance by light irradiation can be used. Examples of the oxime ester compound include CGI-325, Irgacure OXE01, Irgacure OXE02 manufactured by BASF Japan, N-1919, NCI-831 manufactured by Adeka, and the like as commercially available products. Moreover, the compound which has two oxime ester groups in a molecule | numerator can also be used suitably, Specifically, the oxime ester compound which has a carbazole structure represented with the following general formula is mentioned.

(In the formula, X is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms). Group, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms), And Y and Z are each a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, or a carbon atom having 1 carbon atom), substituted with an alkyl group having a C 1-8 alkyl group or a dialkylamino group. Alkyl groups having 8 to 8 alkoxy groups, halogen groups, phenyl groups, phenyl groups (alkyl groups having 1 to 17 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, amino groups, alkyl groups having 1 to 8 carbon atoms) Or substituted with a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or Represents an anthryl group, a pyridyl group, a benzofuryl group, a benzothienyl group, and Ar is a bond or alkylene having 1 to 10 carbon atoms, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene , Anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4′-stilbene-diyl, 4,2′-styrene-diyl, and n is an integer of 0 or 1.)

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

Moreover, the compound which can be represented by the following general formula can also be mentioned as a preferable carbazole oxime ester compound.

(Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms, or a phenyl group optionally substituted with a nitro group, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. R ² represents Represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may be substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group, and R ³ represents , Optionally substituted with an oxygen atom or a sulfur atom, optionally substituted with a phenyl group, optionally substituted with an alkyl group having 1 to 20 carbon atoms, or optionally substituted with an alkoxy group having 1 to 4 carbon atoms R ⁴ represents a nitro group or an acyl group represented by X—C (═O) —, where X is an aryl optionally substituted with an alkyl group having 1 to 4 carbon atoms Group, thienyl group, morpholino A group, a thiophenyl group, or a structure represented by the following formula:

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

Specific examples of the compound having an acyloxyimino group include O, O'-diacetphenone oxime succinate, O, O'-dinaphthophenone oxime succinate, benzophenone oxime acrylate-styrene copolymer, and the like.

Specific examples of the compound having an N-formylated aromatic amino group and an N-acylated aromatic amino group include, for example, di-N- (p-formylamino) diphenylmethane, di-N (p-aceethylamino) Diphenyl melan, di-N- (p-benzamido) diphenyl methane, 4-formylaminotoluylene, 4-acetylaminotoluylene, 2,4-diformylaminotoluylene, 1-formylaminonaphthalene, 1-acetylaminonaphthalene, 1,5-diformylaminonaphthalene, 1-formylaminoanthracene, 1,4-diformylaminoanthracene, 1-acetylaminoanthracene, 1,4-diformylaminoanthraquinone, 1,5-diformylaminoanthraquinone, 3, 3'-dimethyl-4,4'-diformylaminobiphe Le, such as 4,4'-formylamino benzophenones.

Specific examples of the compound having a nitrobenzyl carbamate group or an alkoxybenzyl carbamate group include, for example, bis {{(2-nitrobenzyl) oxy} carbonyl} diaminodiphenylmethane, 2,4-di {{(2-nitrobenzyl) Oxy} toluylene, bis {{(2-nitrobenzyloxy) carbonyl} hexane-1,6-diamine, m-xylidine {{(2-nitro-4-chlorobenzyl) oxy} amide} and the like.

As the photobase generator, oxime ester compounds and α-aminoacetophenone compounds are preferable. As the α-aminoacetophenone compound, those having two or more nitrogen atoms are particularly preferable.

As other photobase generators,
WPBG-018 (Product name: 9-anthrylmethyl N, N'-diethylcarbamate), WPBG-027 (Product name: (E) -1- [3- (2-hydroxyphenyl) -2-propenoyl] piperidine), WPBG-082 (Product name: guanidinium2- (3-benzoylphenyl) propionate), WPBG-140 (Product name: 1- (anthraquinon-2-yl) ethyl imidazolecarboxylate), etc. can also be used.
Also, JP-A-11-71450, WO2002 / 051905, WO2008 / 072651, JP2003-20339, JP2003-212856, JP2003-344992, JP 2007-86763, JP 2007-23235, JP 2008-3581, JP 2008-3582, JP 2009-280785, JP 2009-080452, JP 2010-95686, JP 2010-126662 A, JP 2010-185010 A, JP 2010-185036 A, JP 2010-186054 A, JP 2010-186056 A, JP 2010-275388 A, JP 2010-222586, JP2010-0 4144, JP 2011-107199, JP 2011-236416, it is also possible to use a photobase generator described in the literature such as JP-2011-080032.

The above photobase generators may be used alone or in combination of two or more. The blending amount of the photobase generator in the thermosetting resin composition is preferably 1 to 50 parts by mass, more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the thermoreactive compound. When the amount is less than 1 part by mass, development may be difficult, which is not preferable.

[Maleimide compound]
The thermosetting resin composition of the present invention may contain a maleimide compound.
Examples of maleimide compounds include polyfunctional aliphatic / alicyclic maleimides and polyfunctional aromatic maleimides. Bifunctional or higher maleimide compounds (polyfunctional maleimide compounds) are preferred. Examples of the polyfunctional aliphatic / alicyclic maleimide include N, N′-methylene bismaleimide, N, N′-ethylene bismaleimide, tris (hydroxyethyl) isocyanurate, and aliphatic / alicyclic maleimide carboxylic acid. Isocyanurate skeleton maleic compound obtained by urethanization of isocyanurate skeleton maleimide ester compound obtained by urethanization of tris (carbamate hexyl) isocyanurate and aliphatic / alicyclic maleimide alcohol Maleimides; isophorone bisurethane bis (N-ethylmaleimide), triethylene glycol bis (maleimide ethyl carbonate), aliphatic / alicyclic maleimide carboxylic acid and various aliphatic / alicyclic polyols, or dehydrated ester / Alicyclic maleimide carboxylic acid esters and aliphatic / alicyclic polymaleimide ester compounds obtained by transesterification of various aliphatic / alicyclic polyols; aliphatic / alicyclic maleimide carboxylic acids and various fats Aliphatic / alicyclic polymaleimide ester compounds obtained by ether ring-opening reaction of aliphatic / alicyclic polyepoxides; urethanization of aliphatic / alicyclic maleimide alcohols and various aliphatic / alicyclic polyisocyanates Examples include aliphatic / alicyclic polymaleimide urethane compounds obtained by reaction.

As polyfunctional aromatic maleimide, aromatic polymaleimide ester compounds obtained by dehydrating esterification of maleimide carboxylic acid and various aromatic polyols, or transesterification reaction of maleimide carboxylic acid ester and various aromatic polyols; Aromatic polymaleimide ester compounds obtained by ether ring-opening reaction of carboxylic acid and various aromatic polyepoxides; Aromatic polymaleimide urethane compounds obtained by urethanization reaction of maleimide alcohol and various aromatic polyisocyanates, etc. And aromatic polyfunctional maleimides.

Specific examples of the polyfunctional aromatic maleimide include, for example, N, N ′-(4,4′-diphenylmethane) bismaleimide, N, N′-2,4-tolylene bismaleimide, N, N′-2, 6-tolylene bismaleimide, 1-methyl-2,4-bismaleimide benzene, N, N′-m-phenylene bismaleimide, N, N′-p-phenylene bismaleimide, N, N′-m-toluylene Bismaleimide, N, N′-4,4′-biphenylenebismaleimide, N, N′-4,4 ′-[3,3′-dimethyl-biphenylene] bismaleimide, N, N′-4,4′- [3,3′-dimethyldiphenylmethane] bismaleimide, N, N′-4,4 ′-[3,3′-diethyldiphenylmethane] bismaleimide, N, N′-4,4′-diphenylmethane bismale N, N′-4,4′-diphenylpropane bismaleimide, N, N′-4,4′-diphenyl ether bismaleimide, N, N′-3,3′-diphenylsulfone bismaleimide, N, N ′ -4,4'-diphenylsulfone bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-tert-butyl-4- (4-maleimidophenoxy) phenyl ] Propane, 2,2-bis [3-s-butyl-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] decane, 1,1-bis [2-Methyl-4- (4-maleimidophenoxy) -5-t-butylphenyl] -2-methylpropane, 4,4′-cyclohexylidene-bis [1- ( -Maleimidophenoxy) -2- (1,1-dimethylethyl) benzene], 4,4'-methylene-bis [1- (4-maleimidophenoxy) -2,6-bis (1,1-dimethylethyl) benzene 4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-di-s-butylbenzene], 4,4′-cyclohexylidene-bis [1- (4-maleimidophenoxy) ) -2-cyclohexylbenzene, 4,4′-methylenebis [1- (maleimidophenoxy) -2-nonylbenzene], 4,4 ′-(1-methylethylidene) -bis [1- (maleimidophenoxy) -2, 6-bis (1,1-dimethylethyl) benzene], 4,4 ′-(2-ethylhexylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4 ′-( 1-methylheptylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4′-cyclohexylidene-bis [1- (maleimidophenoxy) -3-methylbenzene], 2,2-bis [ 4- (4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4 -Maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3,5-dimethyl-4- (4 -Maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] pro 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] hexafluoropropane, bis [3-methyl- (4-maleimidophenoxy) phenyl] methane, bis [3,5-dimethyl- (4-Maleimidophenoxy) phenyl] methane, bis [3-ethyl- (4-maleimidophenoxy) phenyl] methane, 3,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1 .02,6] decane, 4,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1.02,6] decane, 3,9-bis [4- (4-maleimide) Phenoxy) phenyl] -tricyclo [5.2.1.02,6] decane, 4,9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [ 2.1.2,6] decane, 1,8-bis [4- (4-maleimidophenoxy) phenyl] menthane, 1,8-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] menthane 1,8-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] menthane and the like.

The blending amount of the maleimide compound is preferably such that the equivalent ratio to the alkali-developable resin (maleimide group: alkali-developable group) is 1: 0.1 to 1:10, and 1: 0.2 to 1: 5. It is more preferable that With such a blending ratio, development is facilitated.

[Polymer resin]
In the thermosetting resin composition of the present invention, a conventionally known polymer resin can be blended for the purpose of improving the flexibility and dryness of the touch of the resulting cured product.
Examples of the polymer resin include cellulose-based, polyester-based, phenoxy-resin-based, polyvinyl acetal-based, polyvinyl butyral-based, polyamide-based, polyamide-imide-based binder polymers, block copolymers, elastomers, and rubber particles. A binder polymer may be used individually by 1 type, and may use 2 or more types together.
By blending the polymer resin, the melt viscosity of the thermosetting resin composition is increased, and the fluidity of the resin in the through-hole portion can be suppressed during post-exposure heating. As a result, a flat substrate that is not recessed on the through hole can be manufactured.

The amount of the polymer resin added is preferably 50 parts by mass or less, more preferably 1 to 30 parts by mass, and particularly preferably 5 to 30 parts by mass with respect to 100 parts by mass of the thermoreactive compound. When the amount of the polymer resin exceeds 50 parts by mass, there is a concern about deterioration of desmear resistance of the thermosetting resin composition, which is not preferable.

(Block copolymer)
The block copolymer is a copolymer having a molecular structure in which two or more kinds of polymers having different properties are connected by a covalent bond to form a long chain.

The block copolymer used in the present invention is preferably an ABA or ABA ′ type block copolymer. Of the ABA and ABA ′ type block copolymers, the central B is a soft block and has a low glass transition point Tg, preferably less than 0 ° C. Is a hard block and has a high Tg, and is preferably composed of polymer units of 0 ° C. or higher. The glass transition point Tg is measured by differential scanning calorimetry (DSC).
Also, among the ABA and ABA ′ type block copolymers, A or A ′ is composed of polymer units having a Tg of 50 ° C. or more, and B is a polymer unit having a Tg of −20 ° C. or less. More preferred is a block copolymer of
In addition, among the ABA and ABA ′ type block copolymers, those in which A or A ′ is highly compatible with the heat-reactive compound are preferable, and B is the same as the heat-reactive compound. Those having low compatibility are preferred. Thus, it is considered that a specific structure in the matrix can be easily shown by using a block copolymer in which the blocks at both ends are compatible with the matrix and the central block is incompatible with the matrix.

A or A ′ preferably includes polymethyl (meth) acrylate (PMMA), polystyrene (PS) or the like, and B preferably includes poly n-butyl acrylate (PBA), polybutadiene (PB) or the like. Further, a hydrophilic unit excellent in compatibility with the matrix described above represented by a styrene unit, a hydroxyl group-containing unit, a carboxyl group-containing unit, an epoxy-containing unit, an N-substituted acrylamide unit, etc. as part of the A or A ′ component It becomes possible to introduce and further improve the compatibility.

The block copolymer used in the present invention is preferably a ternary or more block copolymer, and a block copolymer having a precisely controlled molecular structure synthesized by a living polymerization method is effective for obtaining the effects of the present invention. More preferred. This is considered to be because the block copolymer synthesized by the living polymerization method has a narrow molecular weight distribution, and the characteristics of each unit have been clarified. The molecular weight distribution (Mw / Mn) of the block copolymer used is preferably 3 or less, more preferably 2.5 or less, and still more preferably 2.0 or less.

The block copolymers containing the (meth) acrylate polymer block as described above are, for example, the methods described in JP-A-2007-516326 and JP-A-2005-515281, particularly the following formulas (1) to (4). After the Y unit is polymerized using the alkoxyamine compound represented by any of the above as an initiator, it can be suitably obtained by polymerizing the X unit.

(Wherein n represents 2 and Z represents a divalent organic group, preferably 1,2-ethanedioxy, 1,3-propanedioxy, 1,4-butanedioxy, 1,6-hexanedioxy Selected from among oxy, 1,3,5-tris (2-ethoxy) cyanuric acid, polyaminoamines such as polyethyleneamine, 1,3,5-tris (2-ethylamino) cyanuric acid, polythioxy, phosphonate or polyphosphonate Ar represents a divalent aryl group.)

The weight average molecular weight of the block copolymer is preferably in the range of 20,000 to 400,000, more preferably 50,000 to 300,000. When the weight average molecular weight is less than 20,000, the desired toughness and flexibility effects cannot be obtained, and when the thermosetting resin composition is formed into a dry film or applied to a substrate and temporarily dried. Inferior to tackiness. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity of the thermosetting resin composition becomes high, and the printability and processability may be remarkably deteriorated. When the weight average molecular weight is 50,000 or more, an excellent effect can be obtained in terms of relaxation against external impact.
As a polymer resin, a block copolymer is preferable because it is excellent in crack resistance during a thermal cycle and can suppress warping after curing. The block copolymer is particularly preferable because it can suppress a dent on the through hole and create a substrate having a flat surface. Moreover, it is excellent in the crack tolerance at the time of a thermal cycle by combining with an inorganic filler.

(Elastomer)
An elastomer having a functional group can be added to the thermosetting resin composition of the present invention. By adding an elastomer having a functional group, it is expected that the coating property is improved and the strength of the coating film is also improved. Further, polyester elastomers, polyurethane elastomers, polyester urethane elastomers, polyamide elastomers, polyester amide elastomers, acrylic elastomers, olefin elastomers, and the like can be used. In addition, resins in which a part or all of epoxy groups of epoxy resins having various skeletons are modified with carboxylic acid-modified butadiene-acrylonitrile rubber at both ends can be used. Furthermore, epoxy-containing polybutadiene elastomers, acrylic-containing polybutadiene elastomers, hydroxyl group-containing polybutadiene elastomers, hydroxyl group-containing isoprene elastomers, and the like can also be used. Moreover, these elastomers may be used individually by 1 type, and may use 2 or more types together.
(Rubber particles)
The rubber particles may be any particles as long as they are formed from organic substances such as polymers having a crosslinked structure. For example, as a copolymer of acrylonitrile butadiene, a crosslinked acrylonitrile and butadiene are copolymerized. NBR particles: Copolymerized acrylonitrile, butadiene and carboxylic acid such as acrylic acid; cross-linked polybutadiene, cross-linked silicon rubber, or cross-linked rubber particles having a so-called core-shell structure using NBR as a core layer and cross-linked acrylic resin as a shell layer (Also referred to as “core-shell rubber particles”).
Among these, from the viewpoint of dispersibility control and particle size stability, a core-shell structured crosslinked rubber particle is preferable. A crosslinked rubber having a core-shell structure having a crosslinked acrylic resin as a shell layer and a crosslinked polybutadiene or crosslinked silicone rubber as a core layer. Particles are more preferred.
Cross-linked NBR particles are particles obtained by partially cross-linking acrylonitrile and butadiene at the stage of copolymerization and copolymerization. It is also possible to obtain carboxylic acid-modified crosslinked NBR particles by copolymerizing together carboxylic acids such as acrylic acid and methacrylic acid.
Cross-linked butadiene rubber-cross-linked acrylic resin core-shell rubber particles can be obtained by a two-stage polymerization method in which butadiene particles are polymerized by emulsion polymerization, followed by addition of monomers such as acrylic acid ester and acrylic acid. .
Cross-linked silicone rubber-cross-linked acrylic resin core-shell rubber particles can be obtained by a two-stage polymerization method in which silicon particles are polymerized by emulsion polymerization, followed by addition of monomers such as acrylic acid ester and acrylic acid. .
The size of the rubber particles is 1 μm or less in terms of primary average particle diameter, and is preferably 50 nm to 1 μm. If the primary average particle diameter exceeds 1 μm, the adhesive strength is lowered and the insulation reliability in fine wiring is impaired. The “primary average particle diameter” here refers to the aggregated particle diameter, that is, the secondary particle diameter, not the aggregated single particle diameter.
The primary average particle diameter can be determined by measuring with a laser diffraction particle size distribution meter, for example.
The rubber particles as described above may be used alone or in combination of two or more.
The content of the rubber particles is preferably 50% by mass or less in the resin composition, and more preferably 1 to 30% by mass.
For example, a commercially available product of carboxylic acid-modified acrylonitrile butadiene rubber particles is XER-91 manufactured by Nippon Synthetic Rubber Co., Ltd. Examples of the core-shell particles of butadiene rubber-acrylic resin include Paraloid EXL2655 manufactured by Rohm and Haas Co., Ltd. and AC-3832 manufactured by Ganz Kasei Kogyo Co., Ltd. Examples of the core-shell rubber particles of the crosslinked silicone rubber-acrylic resin include GENIOPERLP52 manufactured by Asahi Kasei Wacker Silicone Co., Ltd.
By using rubber particles, it is possible to improve the crack resistance during the cooling and heating cycle.

[Inorganic filler]
The thermosetting resin composition contains an inorganic filler. The inorganic filler is used for suppressing the curing shrinkage of the cured product of the thermosetting resin composition and improving the properties such as adhesion and hardness. Examples of the inorganic filler include barium sulfate, amorphous silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, boron nitride, and Neuburg Examples include rich earth.

The average particle size (D50) of the inorganic filler is preferably 1 μm or less, more preferably 0.7 μm or less, and even more preferably 0.5 μm. When the average particle diameter exceeds 1 μm, the pattern layer may become cloudy, which is not preferable. Although the lower limit of the average particle diameter (D50) of the inorganic filler is not particularly limited, it is, for example, 0.01 μm or more. Here, the average particle diameter (D50) means an average primary particle diameter.
The average particle diameter (D50) can be measured by a laser diffraction / scattering method. When the average particle diameter is in the above range, the refractive index is close to that of the resin component, the permeability is improved, and the generation efficiency of the base from the photobase generator by light irradiation is increased.
The difference in refractive index between the inorganic filler and the alkali developable resin is preferably 0.3 or less. By setting the difference in refractive index to 0.3 or less, it is possible to suppress light scattering and obtain good deep-curing characteristics. Here, the refractive index of the inorganic filler is preferably 1.4 or more and 1.8 or less. In addition, the refractive index of an inorganic filler can be measured based on JISK7105.
The blending ratio of the inorganic filler is preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 80% by mass or less, based on the total solid content of the thermosetting resin composition. When the blending ratio of the inorganic filler exceeds 80% by mass, the viscosity of the composition increases, and the applicability may decrease or the cured product of the thermosetting resin composition may become brittle.
In a composition in which curing proceeds due to radical reaction, when the content of the inorganic filler increases, the resolution decreases, but in the present invention, since it is a curing reaction by the generated base, the inclusion of the inorganic filler Even when the amount is increased, good resolution can be maintained.
Moreover, it is preferable that the specific gravity of an inorganic filler is 3 or less, More preferably, it is 2.8 or less, More preferably, it is 2.5 or less. When the specific gravity of the inorganic filler is 3 or less, thermal expansion can be suppressed. Examples of the inorganic filler of 3 or less include silica and aluminum hydroxide, and silica is particularly preferable.
Examples of the shape of the inorganic filler include an indeterminate shape, a needle shape, a disc shape, a scale piece, a spherical shape, and a hollow shape. Here, the spherical shape is preferable because it can be blended in the composition at a high ratio. In order to improve moisture resistance, the inorganic filler is more preferably treated with a surface treatment agent such as a silane coupling agent.
Moreover, the crack tolerance at the time of a thermal cycle can be improved by containing an inorganic filler. By containing a large amount of the inorganic filler, warping after curing can be suppressed.
In this invention, it is preferable that the thermal expansion coefficient (CTE) of hardened | cured material is 40 ppm or less, More preferably, it is 30 ppm or less, More preferably, it is 20 ppm or less.

[Organic solvent]
In the thermosetting resin composition of the present invention, an organic solvent can be used for preparing the resin composition or adjusting the viscosity for application to a substrate or a carrier film.

Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. Such an organic solvent may be used individually by 1 type, and may be used as a 2 or more types of mixture.

[Photopolymerizable monomer]
The thermosetting resin composition of the present invention may contain a photopolymerizable monomer as long as the effects of the present invention are not impaired.
Photopolymerizable monomers include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; hydroxyalkyl such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate (Meth) acrylates; mono- or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, Polyhydric alcohols such as trishydroxyethyl isocyanurate or polyvalent (meth) acrylates of these ethylene oxide or propylene oxide adducts (Meth) acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A; glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl (Meth) acrylates of glycidyl ether such as isocyanurate; and melamine (meth) acrylate.
The blending amount of the photopolymerizable monomer is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably based on the solid content excluding the solvent of the thermosetting resin composition. 15 mass% or less. When the blending amount of the photopolymerizable monomer exceeds 50% by mass, the curing shrinkage increases, so that the warpage may increase. When the photopolymerizable monomer is derived from (meth) acrylate, it contains an ester bond. In this case, since the ester bond is hydrolyzed by the desmear treatment, the electrical characteristics may be deteriorated.

(Other optional ingredients)
If necessary, the thermosetting resin composition of the present invention may further contain components such as a mercapto compound, an adhesion promoter, a colorant, an antioxidant, and an ultraviolet absorber.
In particular, in the present invention, even when the content of the colorant is increased, undercuts can be suppressed and good via holes and lines can be formed.
As these, those known in the field of electronic materials can be used. The thermosetting resin composition includes a known and commonly used thickener such as finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, an antifoaming agent such as silicone, fluorine, and polymer, and / or Known and commonly used additives such as a leveling agent, a silane coupling agent, and a rust preventive agent can be blended.
Moreover, you may mix | blend well-known and usual thermosetting resins, such as a block isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound, an episulfide resin, etc. as a thermosetting component.
Furthermore, by containing a phenol resin as the alkali-developable resin and an epoxy resin as the heat-reactive compound, a Tg can be increased, and a cured product having excellent HAST resistance can be obtained without depending on the softening point of the raw material. It can be set as a resin composition. In addition, a photopolymerizable monomer (a low molecular compound compounded to promote photocuring in a photocurable resin composition containing an ethylenically unsaturated group in the molecule and containing a carboxyl group-containing resin as a main component) When it is set as the composition which does not mix | blend, it can be set as the resin composition excellent in tackiness.
In the conventional photocurable resin composition, since the photocuring reaction occurs at room temperature, the Tg of the resin composition rises at the time of curing. As a result, the curing reaction may stop, and the Tg of the resin composition may be lowered. There was a need to design. On the other hand, the alkali development type thermosetting resin composition of the present invention is not limited to Tg before the curing reaction, and can be expected to have a high Tg. Further, the alkali development type thermosetting resin composition of the present invention can be expected to be cured without being inhibited by oxygen.

The thermosetting resin composition of the present invention is useful for forming a pattern layer of a printed wiring board, and is particularly useful as a material for a solder resist or an interlayer insulating layer.

[Pattern formation method]
The pattern formation method which can use the thermosetting resin composition of this invention suitably is the process (A) of forming the resin layer which consists of a thermosetting resin composition in a base material, and light irradiation to a negative pattern shape Then, the step (B) of activating the photobase generator contained in the thermosetting resin composition to cure the light irradiated portion, and the step of forming the negative pattern layer by removing the unirradiated portion by alkali development. (C) is included.
The light irradiation part can be cured by generating a base in the light irradiation part of the thermosetting resin composition by pattern light irradiation. Then, by developing with alkaline aqueous solution, an unirradiated part can be removed and a negative pattern layer can be formed.
Here, in this invention, it is preferable to have the process (B1) of heating a resin layer after a process (B). Thereby, a resin layer can fully be hardened and the pattern layer excellent in the hardening characteristic can be obtained.

[Step (A)]
The pattern forming method will be described with reference to FIG. A process (A) is a process of forming the resin layer which consists of a thermosetting resin composition in a base material. The resin layer is formed by a method in which a liquid thermosetting resin composition is applied and dried on a substrate, or a method in which a thermosetting resin composition is formed into a dry film and laminated on the substrate. be able to.

As a method for applying the thermosetting resin composition to the substrate, a known method such as a blade coater, a lip coater, a comma coater, or a film coater can be appropriately employed. Also, the drying method is a method using a hot-air circulation type drying furnace, IR furnace, hot plate, convection oven, etc., equipped with a heat source of the heating method by steam, and the hot air in the dryer is counter-contacted and supported by the nozzle Known methods such as a method of spraying on the body can be applied.
In addition to printed wiring substrates and flexible printed wiring substrates that have been pre-circuited, paper-phenolic resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven cloth-epoxy Resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, all grades (FR-4, etc.) copper-clad laminates using polyimide, polyethylene, PPO, cyanate ester, etc., polyimide film, A PET film, a glass substrate, a ceramic substrate, a wafer substrate and the like can be used.

[Step (B)]
Step (B) is a step of irradiating light in a negative pattern and activating the photobase generator contained in the thermosetting resin composition to cure the light irradiated portion. In the step (B), it is considered that the photobase generator is destabilized by the base generated in the light irradiation part, and further the base is generated. In this way, the base can be sufficiently cured to the deep part of the light irradiation part by chemically growing.
As a light irradiator used for light irradiation, for example, a direct drawing apparatus capable of irradiating laser light, lamp light, and LED light can be used. As the patterned light irradiation mask, a negative mask can be used.

As the active energy ray, it is preferable to use laser light or scattered light having a maximum wavelength in the range of 350 to 410 nm. By setting the maximum wavelength within this range, the thermal reactivity of the thermosetting resin composition can be improved efficiently. If a laser beam in this range is used, either a gas laser or a solid laser may be used. The irradiation amount varies depending on the film thickness and the like, but can generally be in the range of 100 to 1500 mJ / cm ² , preferably 300 to 1500 mJ / cm ² .

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

[Step (B1)]
In the step (B1), the light irradiation part is cured by heating. Step (B1) can be cured to a deep portion by the base generated in step (B).
The heating temperature is preferably a temperature at which the light-irradiated portion of the thermosetting resin composition is thermally cured, but the non-irradiated portion is not thermally cured.
For example, in the step (B1), the heat generation start temperature or the heat generation peak temperature of the unirradiated thermosetting resin composition is lower than the heat generation start temperature or the heat generation peak temperature of the light irradiated thermosetting resin composition. Heating at a high temperature is preferred. By heating in this way, only the light irradiation part can be selectively cured.
Here, the heating temperature is, for example, 80 to 140 ° C. By setting the heating temperature to 80 ° C. or higher, the light irradiation part can be sufficiently cured. On the other hand, by setting the heating temperature to 140 ° C. or lower, only the light irradiation part can be selectively cured. The heating time is, for example, 10 to 100 minutes. The heating method is the same as the drying method.
In the unirradiated portion, no base is generated from the photobase generator, so that thermosetting is suppressed.

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

[Step (D)]
The pattern forming method preferably further includes an ultraviolet irradiation step (D) after the step (C). By further irradiating with ultraviolet rays after the step (C), the photobase generator remaining without being activated at the time of light irradiation can be activated. The wavelength and irradiation amount (irradiation amount) of ultraviolet rays in the ultraviolet irradiation step (D) after the step (C) may be the same as or different from those in the step (B). A suitable irradiation amount (irradiation amount) is 150 to 2000 mJ / cm ² .

[Step (E)]
The pattern formation method preferably further includes a thermosetting (post-cure) step (E) after the step (C).
When performing a process (D) and a process (E) together after a process (C), it is preferable to perform a process (E) after a process (D).
In the step (E), the pattern layer is sufficiently heat-cured by the base generated from the photobase generator in the step (B) or the steps (B) and (D). Since the unirradiated portion has already been removed at the time of the step (E), the step (E) can be performed at a temperature equal to or higher than the curing reaction start temperature of the unirradiated thermosetting resin composition. Thereby, a pattern layer can fully be thermosetted. The heating temperature is, for example, 160 ° C. or higher.

[Step (F)]
The pattern forming method may further include a laser processing step (F). Fine openings can be formed by laser processing. As the laser, a known laser such as a YAG laser, a CO ₂ laser, or an excimer laser can be used.
The step (F) is preferably performed after the step (C) or after the steps (D) and (E) when the step (F) includes the steps (D) and (E).

[Step (G)]
The pattern formation method of the present invention may further include a desmear process (G) after the process (F).
Step (G) includes a smear swelling step for swelling smear to facilitate removal, a removal step for removing smear, and a neutralization step for neutralizing sludge generated from the desmear liquid used in the removal step.
The swelling step is performed using an alkali chemical such as sodium hydroxide, and facilitates smear removal with a desmear chemical.
In the removing step, smear is removed using an acidic chemical solution containing an oxidizing agent such as dichromic acid or permanganic acid.
In the neutralization step, the oxidizing agent used in the removal step is reduced and removed using an alkaline chemical such as sodium hydroxide.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

(Examples 1 to 19, Comparative Examples 1 to 4)
<Preparation of alkali development type thermosetting resin composition>
According to the formulations shown in Tables 1 to 3 below, the materials described in Examples / Comparative Examples were respectively mixed, premixed with a stirrer, and then kneaded with a three-roll mill to prepare a thermosetting resin composition. The values in the table are parts by mass unless otherwise specified.

<Production of dry film>
As a carrier film, a thermosetting resin composition was applied on a PET film having a thickness of 38 μm using an applicator, and then dried at 90 ° C. for 30 minutes to prepare a dry film. The coating amount was adjusted so that the thickness of the thermosetting resin composition was about 20 μm after drying. Thereafter, the obtained dry film was slit to a predetermined size.

<Laminate>
Prepare a double-sided printed wiring board with a copper thickness of 15μm and a circuit formed on it, and print it on a base material that has been pre-treated with MEC CZ-8100 using a vacuum laminator MVLP-500 A dry film was laminated on the substrate. Lamination conditions were temperature 80 ° C., it was carried out at a pressure of ^5kg / cm 2 / 60sec.

<Evaluation of the B stage state (handling during formation on the substrate)>
Examples 1 to 19 were evaluated for the B-stage state (semi-cured state) of the dry film. Slit processing was performed to the predetermined size of the dry film in which the obtained thermosetting resin composition was formed, and the state of the dry film was confirmed with the following method.
(Evaluation methods)
○: After slit processing, cracking of resin layer and resin powder fall were confirmed. Δ: After slit processing, cracking of resin layer and resin powder fall were confirmed.

<Evaluation of dent on through hole>
As shown in FIG. 3, a double-sided printed wiring board having a diameter of 300 μm and a pitch of 1 mm with copper-plated through-holes formed at a thickness of 0.3 mm was prepared, and MEC CZ-8100 was used. The pretreatment was performed. Thereafter, dry film of 50 μm thickness produced by the method shown in the paragraph of dry film production is simultaneously dried on both sides of the printed wiring board on which through holes are formed, using a vacuum laminator MVLP-500 of Meiki Co., Ltd. The film was laminated. Lamination conditions were temperature 80 ° C., was conducted at a pressure ^5kg / cm 2 / 60sec. After that, the entire surface of the base material provided with the thermosetting resin layer was irradiated with ORC HMW680GW (metal halide lamp, scattered light) on the entire surface with a solid exposure. The light irradiation amount was set as shown in Tables 1 to 3 with reference to the exothermic peak temperature by DSC. Subsequently, the substrate was subjected to heat treatment for 60 to 80 minutes under the temperature conditions shown in Tables 1 to 3. Further, UV irradiation was carried out with an energy amount of 1 J / cm ² using an ORC UV irradiation device, followed by longitudinal curing at 170 ° C./60 min in a hot air circulating drying furnace to complete curing. Thereafter, the surface roughness measuring device SE-700 (manufactured by Kosaka Laboratory) was used to confirm the amount of dent on the through hole.
(Evaluation methods)
○: The maximum recess on the through hole is 5 μm or less. Δ: The maximum recess on the through hole exceeds 5 μm.

<Evaluation of formation of opening pattern>
The substrate provided with the resin layer obtained above was irradiated with a negative pattern with an aperture design size of 100 μm by ORC HMW680GW (metal halide lamp, scattered light). The light irradiation amount was set as described in Tables 1 to 3 below with reference to the exothermic peak temperature by DSC. Next, heat treatment was performed for 60 to 80 minutes under the temperature conditions shown in Tables 1 to 3. Thereafter, the substrate was immersed in a 3 wt% TMAH / 5 wt% ethanolamine mixed aqueous solution at 35 ° C. and developed for 3 minutes, and development and patterning were evaluated according to the following criteria. The obtained results are shown in Tables 1 to 3.
(Evaluation methods)
A: Development is possible with a sodium carbonate aqueous solution in place of the TMAH / 5 wt% ethanolamine mixed aqueous solution. No damage from the developer on the surface of the light irradiated area, and no development residue on the unirradiated area ○: No damage on the surface of the light irradiated area due to the developer, and no development residue on the unirradiated area X: The development residue was confirmed in the non-irradiated part. Alternatively, the unexposed area could not be developed.
XX: A state where both the light irradiated part and the unirradiated part are completely dissolved.
XXX: Undercut was observed in the deep part of the opening

<Line pattern formation>
The substrate provided with the resin layer obtained above was irradiated with a negative pattern having a design value of line / space = 100/100 μm using ORC HMW680GW (metal halide lamp, scattered light). The light irradiation amount was set as described in Tables 1 to 3 below with reference to the exothermic peak temperature by DSC. Next, heat treatment was performed for 60 to 80 minutes under the temperature conditions shown in Tables 1 to 3. Thereafter, the substrate was immersed in a 3 wt% TMAH / 5 wt% ethanolamine mixed aqueous solution at 35 ° C. and developed for 3 minutes, and the obtained linear pattern having a design value of 100 μm was evaluated according to the following criteria. The obtained results are shown in Tables 1 to 3.
(Evaluation methods)
○: The top length of the line was 100 μm and the bottom length was 100 μm, and a pattern as designed was obtained.
Δ: The top length of the line was 100 μm and the bottom length was 60 μm or more and less than 100 μm, and a slight undercut was observed.
X: The top length of the line was 100 μm, the bottom length was less than 60 μm, and a large undercut was observed at the bottom.

(Desmear resistance)
The base material produced by the same method as the base material for which the formation of the opening pattern was evaluated was further irradiated with ultraviolet rays at an energy amount of 1 J / cm ² using an ORC ultraviolet irradiation device, and then subjected to Table 1 in a hot air circulation drying furnace. It was cured for 60 minutes at the post-cure temperature described in (3) (post-cure). Then, laser processing was performed on the light irradiation surface. The light source was processed with a CO ₂ laser (Hitachi Via Mechanics, light source 10.6 μm). Evaluation was made according to the following criteria. In order to give superiority or inferiority in workability, laser processing was performed under the same conditions.
The target of the processing diameter is a top diameter of 65 μm / bottom of 50 μm.
Condition: Aperture (mask diameter): 3.1 mm / pulse width 20 μsec / output 2 W / frequency 5 kHz / number of shots: burst 3 shots The substrate subjected to laser processing is further desmeared with a permanganate desmear aqueous solution (wet method). Processed. As evaluation of desmear resistance, confirmation of the surface roughness of the substrate surface and the state around the laser opening were evaluated according to the following criteria. For confirmation of the surface roughness, each surface roughness Ra was measured with a laser microscope VK-8500 (Keyence Corporation, measurement magnification 2000 times, Z-axis direction measurement pitch 10 nm). The laser opening was observed with an optical microscope.
About chemicals (Rohm & Haas)
Swelling MLB-211 Temperature 80 ℃ / hour 10min
Permanganic acid MLB-213 Temperature 80 ℃ / hour 15min
Reduction MLB-216 Temperature 50 ℃ / hour 5min
Evaluation method A: Surface roughness Ra after permanganate desmear is less than 0.1 μm, and the difference from the processed diameter after laser processing is 2 μm or less ○: Surface roughness Ra after permanganate desmear is 0.1 ~ 0.3μm or less, and the difference from the processed diameter after laser processing is 2 ~ 5μm
×: Surface roughness Ra after permanganate desmear exceeds 0.3 μm and the difference from the processed diameter after laser processing is 5 μm or more

<Evaluation of warpage after curing>
The glossy surface of an 18 μm copper foil obtained by cutting a 20 μm thick dry film produced by the method shown in the dry film production paragraph into a square of 50 mm × 50 mm size using a vacuum laminator MVLP-500 Laminated on one side. Lamination conditions were temperature 80 ° C., was conducted at a pressure ^5kg / cm 2 / 60sec. Thereafter, the copper foil provided with the thermosetting resin layer was irradiated with light on the entire surface by ORC HMW680GW (metal halide lamp, scattered light). The light irradiation amount was set as shown in Tables 1 to 3 with reference to the exothermic peak temperature by DSC. Next, the substrate was heat-treated for 60 to 80 minutes under the temperature conditions shown in Tables 1 to 3. Further, UV irradiation was performed with an energy amount of 1 J / cm ² using an ORC UV irradiation device, followed by curing at 170 ° C./60 min in a hot air circulating drying oven to obtain a copper foil having a thermosetting resin composition on one side. It was. Thereafter, as an evaluation of the warped state of the obtained cured product, the amount of warpage at four end portions was measured with a caliper.
(Evaluation methods)
A: Almost no warpage is seen. The warp amount of the maximum warp portion of the four end portions is less than 5 mm. O: Slight warping was observed. The warp amount of the maximum warp portion among the four end portions is 5 mm or more and less than 20 mm. Δ: The warp amount of the maximum warp portion among the four end portions is 20 mm or more. X: The cured product contracted into a cylindrical shape. The amount of warp at the end could not be measured with calipers

<CTE measurement>
In accordance with the method described in the section of dry film production, each dry film with a thickness of 40 μm was produced. Thereafter, a dry film was laminated on the glossy surface side of the 18 μm copper foil by using a vacuum laminator MVLP-500 of Meiki Co., Ltd. Lamination conditions were temperature 80 ° C., was conducted at a pressure ^5kg / cm 2 / 60sec. Thereafter, the entire surface was exposed with ORC HMW680GW (metal halide lamp, scattered light). The light irradiation amount was set as described in Tables 1 to 3 below with reference to the exothermic peak temperature by DSC. Next, heat treatment was performed for 60 to 80 minutes under the temperature conditions shown in Tables 1 to 3. Thereafter, UV irradiation was performed with an energy amount of 1 J / cm ² using an ORC UV irradiation device, and then complete curing was performed at 170 ° C./60 min in a hot air circulating drying furnace. Then, it peeled from copper foil and obtained the resin composition as described in an Example and a comparative example. Thereafter, the obtained resin composition was cut into a strip shape having a width of 3 mm and a length of 10 mm, and CTE measurement (thermal expansion coefficient) was evaluated by the TMA method (tensile method) described in JIS-C-6481. I did it. The rate of temperature increase was 5 ° C./min, and the thermal expansion coefficient of Tg or less was evaluated. The thermal expansion coefficient was an average thermal expansion coefficient in the temperature range of 25 ° C. to 100 ° C., and the unit was ppm.
The obtained CTE values are shown in Tables 1 to 3.

<Evaluation of thermal cycle characteristics>
The printed wiring board subjected to the permanganate desmear treatment as described above was further subjected to nickel 0.5 μm and gold plating 0.03 μm using commercially available electroless nickel plating bath and electroless gold plating bath. Plating was performed, and the pattern layer was gold-plated. About the obtained printed wiring board, the thermal cycle characteristic evaluation was performed. The processing conditions are as follows: -65 ° C for 30 min, 150 ° C for 30 min, heat history is added, and after 2000 cycles, the surface of the pattern layer and the periphery are observed with an optical microscope, and cracks are observed according to the following criteria: Was evaluated. The number of observation patterns was 100 holes. The obtained results are shown in Tables 1 to 3 below.
(Evaluation methods)
◎ ○: No cracks are generated on the surface and the periphery of the pattern layer. ◎: Crack generation rate of the periphery of the pattern layer is less than 10%. ○: Crack occurrence rate of the periphery of the pattern layer is 10% or more and less than 30%. Over 30% crack generation rate in the peripheral area

<Method of measuring refractive index of heat-reactive compound, maleimide compound, and alkali-developable resin>
Measuring apparatus: Appe refractometer Measuring conditions: Wavelength 589.3 nm, temperature 25 ° C.

(Thermosetting compound + alkali developable resin + photobase generator + filler)

(+ Polymer resin)

(Comparative example)

The components in Tables 1 to 3 are as follows.
(Thermo-reactive compound)
* 828: Bis-A type liquid epoxy (equivalent 190 g / eq), Mitsubishi Chemical Corporation * HP-4032: naphthol type epoxy (equivalent 150 g / eq), DIC * HP-7200 H60: dicyclopentadiene type epoxy (equivalent 265 g) / Eq), dissolving DIC with cyclohexanone. 60% solids
(Maleimide compound)
* UVT-302: Acrylic polymer with maleimide groups in the side chain (equivalent 320 g / eq), Toagosei Co., Ltd. (alkali developable resin)
* HF-1M H60: phenol novolak (hydroxyl equivalent: 105 g / eq), Meiwa Kasei Co., Ltd. dissolved in cyclohexanone. 60% solids
MEH-7851M H60: Biphenyl / phenol novolak (hydroxyl equivalent: 210 g / eq), Meiwa Kasei Co., Ltd. dissolved in cyclohexanone. 60% solids.
* Johncrill 586 H60: Styrene acrylic acid copolymer resin, Mw = 3100, solid content acid value = 108 mgKOH / g, Johnson polymer was dissolved in cyclohexanone. 60% solids
* John Cryl 68 H60: Styrene acrylic acid copolymer resin, Mw = 10000, acid value 195 mg KOH / g, Johnson Polymer Co., Ltd. (photobase generator)
* Irg369: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, BASF Japan * WPBG-140: 1- (anthraquinone-2-yl) ethylimidazole carboxylate, Wako Jun Yakusha (polymer resin)
* YX8100 BH30: Phenoxy resin. Mitsubishi Chemical Corporation. Solid content 30%
(Inorganic filler)
* SO-C2: spherical silica D50 = 0.5 μm, refractive index = 1.4 to 1.5, Admatechs, specific gravity: 2.2 g / cm ³
* AO-502: Spherical alumina D50 = 0.7 μm, Refractive index = 1.76, Admatex, specific gravity: 3.9 g / cm ³
* Hijilite H-42M: Aluminum hydroxide D50 = 1.0 μm, Refractive index = 1.65, Showa Denko KK, Specific gravity: 2.4 g / cm ³
* B-30: Barium sulfate, D50 = 0.3 μm, Refractive index = 1.64, Sakai Chemical Co., Ltd., specific gravity: 4.3 g / cm ³
(Other)
* R-2000: Cresol novolak, acrylic acid, THPA-modified resin (solid content 61%, solid content acid value 87 mgKOH / g, DIC)
* DPHA: Dipentaerythritol hexaacrylate_Nippon Kayaku Co., Ltd. * IRG-184: 1-hydroxycyclohexyl-phenylketone_Ciba Japan

As shown in Tables 1 to 3, in Examples 1 to 19, it was possible to form a pattern by alkali development, and it was confirmed that the obtained pattern was excellent in curing characteristics and cooling cycle characteristics.
In Examples 15 and 16 and the like, the polymer resin is added to increase the melt viscosity of the thermosetting resin composition and suppress the fluidity of the resin in the through-hole portion during heating after exposure. be able to. As a result, a flat substrate that is not recessed on the through hole can be manufactured.
In Examples 18 and 19, good curability was obtained during the cooling / heating cycle even when the content of the inorganic filler was considerably high.
On the other hand, with the photoradical composition of Comparative Example 4, pattern formation by alkali development became difficult. The line shape was also poor. Furthermore, the warpage after curing was large, and the curability during the cooling and heating cycle was also inferior.

<DSC measurement immediately after light irradiation>
The base material provided with the resin layer obtained in Example 1 was irradiated with a negative pattern with ORC HMW680GW (metal halide lamp, scattered light). About each base material, the light irradiation of the pattern was performed by making irradiation amount into 1000 mJ / cm < ² >. After light irradiation, the resin layer is scraped off from the base material, and immediately heated to 30-300 ° C. at a temperature increase rate of 5 ° C./min in Seiko Instruments Inc. DSC-6200. DSC measurement was performed. Moreover, DSC measurement was similarly performed with respect to the cured layer which consists of a thermosetting resin composition immediately after ultraviolet irradiation and before postcure.
2, the unirradiated portions, the light irradiation portion of the irradiation amount 1000 mJ / cm ^2, a DSC chart of the light irradiation unit that is UV irradiated with further 1000 mJ / cm ² was irradiated with light irradiation amount 1000 mJ / cm ^2. In the light irradiation part of Example 1, the peak shifted to the low temperature side by light irradiation.

(Comparative Example 5)
A double-sided printed wiring substrate having a copper thickness of 15 μm and a circuit formed thereon having a thickness of 0.4 mm was prepared, and pre-treated using MEC CZ-8100. Thereafter, the product name PSR-4000G23K (Taiyo Ink Manufacturing Co., Ltd., photocurable resin composition containing an alkali-developable resin having an epoxy acrylate structure) was applied by screen printing so that it would be 20 μm after drying. I did it. Next, after drying at 80 ° C./30 min in a hot air circulating drying furnace, the film was irradiated with a negative pattern with ORC HMW680GW (metal halide lamp, scattered light) at an irradiation amount of 300 mJ / cm ² . Thereafter, development was performed with a 1 wt% sodium carbonate aqueous solution for 60 seconds, followed by heat treatment at 150 ° C./60 min using a hot-air circulating drying oven to obtain a patterned cured coating film.
Thereafter, desmear resistance was evaluated in the same manner as in Example 2 above. As a result, the desmear resistance was “x”.

Claims (4)

1. Alkali developable resin,
   Thermoreactive compounds,
   Inorganic filler, and
   A photobase generator,
   An alkali-developable thermosetting resin composition characterized in that a negative-type pattern can be formed by alkali development by an addition reaction between the alkali-developable resin and the heat-reactive compound by selective light irradiation. object.
2. 2. The alkali developing type thermosetting resin composition according to claim 1, wherein the inorganic filler has an average particle size of 1 μm or less.
3. An exothermic peak is generated in DSC measurement by light irradiation, or the heat generation starting temperature in DSC measurement of the alkali-development-type thermosetting resin composition irradiated with light is that of the non-irradiated alkali-development-type thermosetting resin composition. DSC measurement of an alkali development type thermosetting resin composition that is lower than the heat generation start temperature in DSC measurement or has an exothermic peak temperature in DSC measurement of an alkali development type thermosetting resin composition that has been irradiated with light. The alkali-developable thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is lower than an exothermic peak temperature.
4. A printed wiring board comprising a pattern layer comprising the alkali development type thermosetting resin composition according to any one of claims 1 to 3.

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