WO2006129663A1

WO2006129663A1 - Curable resin composition and cured object obtained therefrom

Info

Publication number: WO2006129663A1
Application number: PCT/JP2006/310781
Authority: WO
Inventors: Yoshikazu Daigo; Shoji Minegishi; Gen Itokawa
Original assignee: Taiyo Ink Mfg. Co., Ltd.
Priority date: 2005-05-31
Filing date: 2006-05-30
Publication date: 2006-12-07
Also published as: CN101189551B; KR20080008387A; TW200710571A; TWI326393B; KR100928362B1; CN101189551A

Abstract

A curable resin composition which contains an inorganic filler in a high concentration. It can easily attain a reduced coefficient of thermal expansion, increased coefficient of thermal conductivity, reduced water absorption, etc. The composition can be developed with a dilute aqueous alkali solution. It is reduced in the content of gasifiable components to be released at high temperatures from organic ingredients including the resin. The resin composition is an alkali-developable insulating resin composition comprising (A) a carboxylated copolymer resin, (B) a compound having two or more reactive groups which cure by the action of actinic energy rays, (C) a photopolymerization initiator, and (D) an inorganic filler, the content of the inorganic filler (D) being 65 mass% or higher based on the solid ingredients.

Description

Curable resin composition and cured product thereof

Technical field

[0001] The present invention relates to a curable resin composition filled with an inorganic filler at a high concentration and developable with a dilute alkaline aqueous solution, and a cured product thereof. In more detail, the present invention can easily achieve low linear expansion coefficient, high thermal conductivity, low water absorption, etc. by filling the inorganic filler at a high concentration. Less gasification components are released from organic components such as at high temperatures! Relates to a curable resin composition developable with a dilute alkaline aqueous solution and its cured product.

Background art

In recent years, with the downsizing and high performance of electronic devices, there is a demand for higher density and higher functionality of semiconductors. For this reason, circuit boards on which semiconductors are mounted are also required to be small and dense. Responding to such demands for higher density, a resin insulation layer is formed on the core substrate, a copper foil layer is formed by electroless copper plating, etc., and a multilayer build-up substrate or a semiconductor chip for circuit formation BGA (Ball Grid Array) and CSP (Chip Scale Package) etc. have been introduced.

[0003] A resin composition (see, for example, Patent Document 1 and Patent Document 2) used for such a build-up substrate or a package substrate is based on a low molecular weight epoxy compound. It is a fat composition, and it has been difficult to highly fill inorganic fillers such as fused silica useful for a low linear expansion coefficient and aluminum oxide for improving heat dissipation.

[0004] On the other hand, a metal plate such as copper or aluminum is used as a circuit board having good heat dissipation, and an electric insulation layer such as a pre-preda or a thermosetting resin composition is provided on one or both surfaces of the metal plate. Examples thereof include a metal base substrate on which a circuit pattern is formed (see, for example, Patent Document 3). However, a strong metal base substrate requires a thin insulating layer due to the poor thermal conductivity of the electrical insulating layer. As a result, there may be a problem of withstand voltage.

[0005] To solve the problem of heat dissipation, a method of attaching a heat sink to the upper part of the semiconductor is also considered. Force Generated About 50% of the released heat is stored on the package substrate, so the heat dissipation of the knock substrate still becomes a problem.

[0006] In addition, in recent mobile phones and the like in which a large number of surface-mounted light emitting diodes are used for push button display, there is a problem that most of the heat dissipated from the light emitting diodes accumulates on the substrate. Specifically, for example, a light-emitting diode chip is disposed on a resin insulating layer on which a terminal portion is formed, and is packaged with a sealing resin that also serves as a lens layer on top of the light-emitting diode chip. In the diode, the heat dissipation of the resin insulation layer becomes a problem.

[0007] In addition, in the conventional liquid photo solder resist composition (see, for example, Patent Document 4), the content of the inorganic filler is 50% by mass or less, and inorganic fillers such as barium sulfate, silica, talc, and clay are used. Materials, particularly barium sulfate, have been frequently used. In this system, the water absorption rate of the coating film was 1.2 to 1.5% by mass, and popcorn phenomenon due to water absorption and galvanic corrosion due to moisture in the coating film were problematic. Another problem is that polybasic acid anhydrides and photopolymerization initiators that are decomposed and released from the resin at high temperatures gasify and cause malfunction of electronic devices.

[Patent Document 1] JP-A-9 148748 (Claims)

[Patent Document 2] JP-A-11 288091 (Claims)

[Patent Document 3] JP-A-6-224561 (Claims)

[Patent Document 4] Japanese Patent Application Laid-Open No. 61-243869 (Claims)

Disclosure of the invention

[0009] [Problems to be solved by the invention]

The present invention was developed in view of the above problems, and its main purpose is to reduce the linear expansion coefficient, increase the thermal conductivity, reduce the water absorption rate, etc. by filling the inorganic filler with a high concentration. To provide a curable resin composition that can be easily realized, can be developed with a dilute aqueous alkali solution, and emits less gasification components at high temperatures from organic components such as resin. I will.

[ooio] In addition, the curable resin composition obtained by irradiation with active energy rays and Z or thermosetting is excellent in low linear expansion coefficient, high thermal conductivity, low water absorption, etc. It is to provide a cured product with a small amount of gasified components released, such as fats and other organic components. [0011] [Means for solving the problems]

As a result of intensive research aimed at realizing the above object, the inventors have found that (A) a carboxyl group-containing copolymer resin, (B) a compound having two or more reactive groups that are cured by active energy rays, (C) photopolymerization A composition that also has an initiator power is excellent as a binder resin component. (D) It is possible to fill an inorganic filler with a solid content of 65% by mass or more. Depending on the type of inorganic filler (D), Low linear expansion coefficient, high thermal conductivity, low water absorption, etc. can be easily realized, development is possible with dilute alkaline aqueous solution, and less gasification components are released at high temperatures from organic components such as resin. The present inventors have found that a curable resin composition can be provided and have completed the present invention.

As a more preferred embodiment, the carboxyl group-containing copolymer resin (A) is a compound represented by the following general formula (I) or (A)

[Chemical 1]

[Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkylene group having 2 to 6 carbon atoms, R ³ is an alkylene group having 3 to 3 carbon atoms: R ⁴ Represents a dihydrochloride anhydride residue, which is a carboxyl group-containing copolymer resin containing) as a constituent component.

[0014] The compound (B) having two or more reactive groups that are cured by active energy rays is a compound having two or more ethylenically unsaturated bonds, and the photopolymerization initiator (C) is From the viewpoint of photocurability, a radical photopolymerization initiator is preferred.

[0015] Further, in order to easily realize the desired characteristics in the curable resin composition of the present invention, the content of the inorganic filler (D) is 80% by mass or more in the solid content. There is preferable. From the viewpoint of increasing the thermal conductivity, the inorganic filler (D) preferably has a thermal conductivity of 15 W 15πι · Κ or more, and is particularly preferably acid aluminum.

[0016] Further, as a second aspect of the curable resin composition of the present invention, there is provided a photocurable thermosetting composition containing (i) a thermosetting component in addition to the above composition. Is done. In this preferred embodiment, the thermosetting component (Ε) is a polyfunctional epoxy resin having two or more oxysilane rings in the molecule.

[0017] As yet another aspect, the curable resin composition of the present invention is preferably insulating.

[0018] As another aspect, the curable resin composition is irradiated with active energy rays and

Provided is a cured product that is excellent in low coefficient of linear expansion, high thermal conductivity and low water absorption obtained by drought or heat curing, and also has little gasification component released, such as rosin and other organic components at high temperatures. The From the viewpoint of high thermal conductivity, the cured product preferably has a thermal conductivity of lWZm′K or more.

[0019] [Effect of the invention]

Since the carboxyl group-containing copolymer resin (A) used in the curable resin composition of the present invention is a copolymer resin, it can maintain a high viscosity even when diluted with an organic solvent, As a result, it is possible to highly fill the inorganic filler, and it is possible to easily achieve a low linear expansion coefficient, a high thermal conductivity, a low water absorption, and the like of the cured product.

[0020] The curable resin composition of the present invention, which can easily achieve such low linear expansion coefficient, high thermal conductivity, low water absorption, etc., of the cured product, is likely to cause warpage problems. It can be suitably used as a solder resist for a thin build-up substrate or a package substrate on which a semiconductor chip with a large amount of heat generation is mounted.

[0021] Further, by using an inorganic filler having high visible light reflectivity and an inorganic filler having a light-shielding property.

The solder resist can be imparted with light reflectivity, light diffusibility or light shielding property, and can be suitably used for optical devices such as LED devices that require optical functions.

[0022] Furthermore, since there are few organic components such as rosin, it is possible to provide a highly reliable substrate with less gasified components released at high temperatures.

BEST MODE FOR CARRYING OUT THE INVENTION [0023] The basic embodiment of the curable resin composition of the present invention includes (A) a carboxyl group-containing copolymer resin, (B) a compound having two or more reactive groups that are cured by active energy rays, (C It is characterized by containing a photopolymerization initiator and (D) an inorganic filler, and the content ratio of the inorganic filler (D) is 65% by mass or more in the solid content. Further, in order to improve heat resistance, (E) a thermosetting component may be contained.

[0024] Hereinafter, each component of the curable resin composition of the present invention will be described in detail.

[0025] First, as the carboxyl group-containing copolymer resin (A), a known and commonly used copolymer resin having a carboxyl group in the molecule can be used. Furthermore, a copolymer resin having an ethylenically unsaturated bond in the molecule can be used more favorably than the surface strength of development resistance.

[0026] Specific examples include carboxyl group-containing copolymer resins as listed below.

[0027] (1) A carboxyl group-containing copolymer obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and one or more other compounds having an unsaturated double bond. Resin,

(2) Copolymers of unsaturated carboxylic acids such as (meth) acrylic acid and one or more other compounds having unsaturated double bonds with glycidyl (meth) atarylate or 3, 4— Photosensitivity obtained by adding an ethylenically unsaturated group as a benton with a compound having an epoxy group and an unsaturated double bond such as epoxycyclohexylmethyl (meth) acrylate or (meth) acrylic acid chloride. -Functional carboxyl group-containing copolymer resin

(3) A compound having an unsaturated double bond with an epoxy group, such as glycidyl (meth) acrylate or 3, 4-epoxycyclohexylmethyl (meth) acrylate, and another compound having an unsaturated double bond This copolymer is reacted with an unsaturated carboxylic acid such as (meth) acrylic acid, and the resulting secondary hydroxyl group is reacted with a polybasic acid anhydride. Fat,

(4) 2-hydroxyethyl (meth) acrylate, etc. for copolymers of acid anhydrides with unsaturated double bonds such as maleic anhydride and other compounds with unsaturated double bonds A photosensitive polymer obtained by reacting a hydroxyl group with a compound having an unsaturated double bond. Bauxyl group-containing copolymer resin

(5) A carboxyl group-containing resin obtained by reacting a hydroxyl group-containing copolymer such as a polyvinyl alcohol derivative with a polybasic acid anhydride,

(6) Further obtained by reacting the carboxyl group-containing resin with a compound having an unsaturated double bond with an epoxy group such as glycidyl (meth) acrylate or 3, 4-epoxycyclohexylmethyl (meth) acrylate. And photosensitive carboxyl group-containing copolymer resin.

[0028] As a constituent of these copolymerized resin (A), a compound represented by the following general formula (I) or (I)

[Chemical 2]

[In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkylene group having 2 to 6 carbon atoms, R ³ is an alkylene group having 3 to 3 carbon atoms: R ⁴ Represents a dihydrochloric acid anhydride residue.) A carboxyl group-containing copolymer resin containing) is preferred as a binder resin when highly filling the inorganic filler (D).

[0030] In the present specification, "(meth) atalylate" is a term that collectively refers to talate, metatalate, and a mixture thereof, and other similar expressions! The same is true.

[0031] The solid content acid value of the carboxyl group-containing copolymerized resin (A) is in the range of 40 to 200 mgKOHZg, more preferably in the range of 80 to 120 mgKOHZg. When the acid value of the carboxyl group-containing copolymer resin is less than 40 mgKOH / g, alkali development becomes difficult.On the other hand, when it exceeds 200 mgKOHZg, it is necessary to dissolve the exposed area by the developer. This is not preferable because the lines are thinned or, depending on the case, dissolution and peeling with a developer without distinction between exposed and unexposed areas makes it difficult to draw a normal resist pattern.

[0032] The weight average molecular weight of the carboxyl group-containing copolymer resin (A) is 2,000 to 50,000, preferably <ί, 5,000 to 20,000. Desire! / ヽ. When the weight average molecular weight force is less than 2,000, it is not preferable because the dryness to touch of the coating film is lowered and it becomes difficult to obtain the impact resistance of the cured product. On the other hand, when the weight average molecular weight exceeds 50,000, the developability is lowered, which is preferable.

Next, the compound (2) having two or more reactive groups that are cured by the active energy ray includes a compound having two or more ethylenically unsaturated bonds, and cationic polymerization such as an oxsilane ring or an oxetane ring. And photodimeric compounds such as chalcone cinnamate, and other cyclic ether compounds. Among these, from the viewpoint of photocurability and storage stability,

A compound having two or more ethylenically unsaturated bonds is preferred.

[0034] The compound having two or more ethylenically unsaturated bonds is used for photocuring and insolubilizing the carboxyl group-containing copolymer resin (榭) in a dilute alkaline aqueous solution. It is. Typical examples include 2-hydroxyethyl (meth) acrylate, 1,4 butanediol di (meth) acrylate, 1,6 hexanediol di (meth) acrylate, neopentyl. Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopenta-ldi (meth) acrylate Forced prolataton-modified dicyclopenta-di-di (meth) acrylate, ΕΟ-modified di- (meth) acrylate, arylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) Atalylate, dipentaerythritol Li (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ΡΟ modified trimethylol propane tri (meth) acrylate, tris (ataryl oxychase) Til) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hex (meth) acrylate, force prolatataton modified dipentaerythritol hex (meth) acrylate, etc. I can get lost.

Of these, from the standpoint of development resistance, bifunctional or higher, preferably trifunctional or higher (meth) acrylate is preferable.

[0036] The amount of the compound (B) having two or more reactive groups that are cured by active energy rays, such as a compound having two or more ethylenically unsaturated bonds, is the above-mentioned carboxyl group-containing copolymer IV. Fat (A) With respect to 100 parts by mass, 5 to 100 parts by mass is particularly preferable, and 10 to 50 parts by mass is particularly preferable. When the component (B) is less than 5 parts by mass, sufficient curability cannot be obtained and a pattern shape as designed cannot be obtained. On the other hand, when the amount exceeds 100 parts by mass, the dryness to the touch is deteriorated, which is not preferable.

[0037] Examples of the photopolymerization initiator (C) used in the present invention include compounds that generate active groups upon irradiation with active energy rays, such as photoradical polymerization initiators, photopower thione polymerization initiators, and photopolymers. -On polymerization initiators and the like. Among these, photo radical polymerization initiators are preferred from the viewpoint of photocurability, storage stability, electrical properties of cured products, and the like.

[0038] Examples of the radical photopolymerization initiator include those known and commonly used, for example, benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2, 2- 1-Phenylacetophenone, 2,2-Diethoxy-1-2-Ph-Luacetophenone, 2,2-Diethoxy-1-2-Pha-Luacetophenone, 1,1-Dichloroacetophenone, etc .; 2-Methyl 1 [4 (Methylthio) phenol] 2 Morpholinopropane 1-one, 2-Benzyl-1-2-dimethylamino-1- 1- (4-Morpholinol) monobutanone — 1-aminoacetophenones; 2-methyl Anthraquinone, 2-ethyl anthraquinone, 2 tertiary butyl anthraquinone, 1 black mouth Anthraquinones such as laquinone; thioxanthones such as 2,4 dimethylthioxanthone, 2,4 jetylthioxanthone, 2 chlorothioxanthone, 2,4 diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone Benzophenones such as: xanthones; (2, 6 dimethoxybenzoyl) -2,4,4 pentylphosphine oxide, bis (2,4,6 trimethylbenzoyl) phenolphosphine oxide, 2 , 4, 6 Trimethylbenzoyldiphosphine oxide, ethyl 2, 4 Phosphine oxides such as 1,6-trimethylbenzoylphosphinate and the like, and these known and commonly used radical photopolymerization initiators can be used alone or in combination of two or more.

[0039] The blending amount of the photopolymerization initiator (C) such as the photoradical polymerization initiator is 0.1 to 30 parts by mass with respect to 100 parts by mass of the carboxyl group-containing copolymer resin (榭). Preferably, it is contained in a proportion of 2 to 20 parts by mass. The compounding power of this component (C) Carboxyl group-containing copolymer resin (榭) With respect to 100 parts by mass, if less than 0.1 part by mass, the photocurability and workability deteriorate, which is not preferable. On the other hand, if it exceeds 30 parts by mass, the coating film properties deteriorate, which is not preferable.

[0040] The inorganic filler (D) used in the curable resin composition of the present invention can be appropriately selected. For example, known and commonly used inorganic fillers that can be used in insulating curable resin compositions include crystalline silica, fused silica, barium sulfate, talc, clay, aluminum hydroxide, aluminum oxide, boron nitride. , Aluminum nitride, magnesium oxide, magnesium carbonate, zinc oxide, calcium carbonate, barium titanate and the like. These are properly used according to the purpose and purpose. In addition, examples of known and commonly used inorganic fillers that can be used in the conductive curable resin composition include conductive metal powders such as copper powder and silver powder, and these can be properly used depending on the application and purpose.

[0041] Among these inorganic fillers, as the inorganic filler (D) having a thermal conductivity of 15 WZm'K or more, aluminum oxide having a purity of 92% or more (40 WZm · K) having a thermal conductivity of about 15 WZm · K. , Boron nitride (40WZm'K or more), aluminum nitride (260WZm'K), magnesium oxide (60WZm'K), zinc oxide (45WZm'K) and other insulating compounds, copper powder (380WZm'K) And conductive metal powders such as silver powder (420WZm'K).

[0042] Among these, fused silica is preferable from the viewpoint of low linear expansion coefficient, and acid aluminum is preferable from the viewpoint of high thermal conductivity and chemical resistance.

[0043] The particle size of these inorganic fillers (D) is 30 μm or less, preferably 20 μm or less, and spherical ones are preferred for high filling. In addition, it is preferable to mix those with two or more particle sizes that have a particle size distribution that results in closest packing. Inorganic filler (D) When the particle size of the particles exceeds 30 m, the inorganic filler (D) is dropped from the surface of the coating film, or the blending ratio of the inorganic filler (D) is decreased.

[0044] The amount of the inorganic filler (D) to be blended is 65% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more in the solid (cured product). When the blending amount of the inorganic filler (D) is less than 65% by mass, a low linear expansion coefficient, a high thermal conductivity, and a low water absorption rate can be achieved by highly filling the inorganic filler that is the object of the present invention. This is not preferable because it is difficult to make it.

[0045] The curable resin composition of the present invention may contain a thermosetting component (E) in order to improve the heat resistance of the cured product. Examples of the thermosetting component include a polyfunctional epoxy resin having two or more oxirane rings in the molecule, a polyfunctional oxetane compound having two or more oxetane rings in the molecule, and a thermosetting polyimide resin. , Melamine rosin and the like.

[0046] The blending amount of such a thermosetting component (E) is 0.1 to 50 parts by mass, preferably 2 to 30 parts by mass, with respect to 100 parts by mass of the carboxyl group-containing copolymer resin (A). Part.

Of these, polyfunctional epoxy resins are preferably used from the viewpoints of curability, storage stability, and cured coating film characteristics.

[0048] Examples of the polyfunctional epoxy resins include known and commonly used epoxy compounds such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and brominated bisphenols. Phenolic type A epoxy resin, hydrogenated bisphenol A type epoxy resin, biphenol type epoxy resin, bixylenol type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, brominated phenol Glycidyl ether compounds such as borac-type epoxy resin and bisphenol A novolak-type epoxy resin; glycidyl ester compounds such as terephthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester and dimer acid diglycidyl ester; Ginoleisocyanurate, N, N, Ν ' , Ν, -tetraglycidyl metaxylene diamine, Ν, Ν, Ν ', Ν'-tetraglycidyl bisaminomethylcyclohexane, Ν, Ν-diglycidyl diamine, and other glycidylamine compounds; polybutadiene Examples thereof include epoxy polybutadiene obtained by acidifying a resin having an unsaturated bond. Furthermore, glycidyl (meth) acrylate copolymer coagulants can be used. [0049] These polyfunctional epoxy compounds can be used alone or in combination of two or more. The blending amount is in the range of 0.6 to 2.0 equivalents, preferably 0.8 to 1.5 equivalents, with respect to 1 equivalent of carboxyl groups of the carboxyl group-containing copolymer resin (A). . If the amount of the polyfunctional epoxy compound is less than the above range, the carboxyl group remains, which is not preferable because the heat resistance, alkali resistance, electrical insulation and the like are lowered. On the other hand, when the above range is exceeded, the low molecular weight polyfunctional epoxy resin remains, which is not preferable because the strength of the coating film is lowered.

[0050] The curable resin composition of the present invention is preferably added with (F) a wetting and dispersing agent in order to facilitate higher filling. Examples of such a wet 'dispersant (F) include compounds and polymer compounds having a polar group having an affinity for an inorganic filler (D) such as a carboxyl group, a hydroxyl group, and an acid ester, such as phosphoric acid. Acid-containing compounds such as esters, copolymers containing acid groups, hydroxyl group-containing polycarboxylic acid esters, polysiloxanes, salts of long-chain polyaminoamides and acid esters, and the like can be used. Disperbyk (registered trademark) 1 101, 1 103, -110, -111, -160, -171, -174, which are commercially available and can be particularly suitably used as the wetting and dispersing agent (F). —190, —300, Bykumen (registered trademark), BYK-P105, — P104, — P104S, — 240 (all manufactured by Bic 'Chemi Co.), EFKA —Polymer 150, EFKA—44, —63, —64, -65, -66, -71, -764, -766, N (V, deviation is also made by F Power Co.).

[0051] The blending amount of such a wet dispersant (F) is suitably from 0.01 to 5 parts by mass per 100 parts by mass of the inorganic filler (D). If the blending amount of the wetting / dispersing agent (F) is less than the above range, the effect of adding the wetting / dispersing agent cannot be obtained, and it becomes difficult to achieve a high filling of the composition. On the other hand, if it is added in excess of the above range, the proportion of the component that is not photocured increases, which is not preferable because the strength of the coating film is reduced and the thixotropic property of the composition is increased.

[0052] If necessary, an organic solvent may be added to the curable resin composition of the present invention for viscosity adjustment. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; closed sorb, methyl closed sorb, butinoreserosonoreb, Carbitol, methinorecanorebitonore, butinorecarbitol, propylene glycolenomonomethinole ether, dipropyleneglycol Glycol ethers such as dimethyl ether, dipropylene glycol jetyl ether, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl acetate solvate, carbitol acetate, butinole Esters such as carbitoleole acetate, propylene glycolenomonomethinoleatenoacetate, dipropylene glycol monomethyl ether acetate and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum ether, petroleum naphtha, Organic solvents such as petroleum-based solvents such as solvent naphtha can be used. These organic solvents can be used alone or in combination of two or more.

[0053] The blending amount of these organic solvents is not particularly limited and may be appropriately adjusted according to the coating method, but is generally 50% by mass or less, preferably 30% by mass in the composition. It is as follows. If the content of the organic solvent is large, the sedimentation speed of the inorganic filler (D) increases and the storage stability decreases, which is not preferable.

[0054] The curable resin composition of the present invention may further include phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and the like, if necessary. Known and conventional colorants, known and conventional thickening agents such as quinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol and phenothiazine, and known and conventional thickening agents such as finely divided silica, organic bentonite and montmorillonite Addition of known and commonly used additives such as antifoaming agents such as adhesives, silicones, fluorines, and polymers, and silane coupling agents such as Z or leveling agents, imidazole, thiazole, and triazoles can do.

[0055] The curable resin composition of the present invention is adjusted to a viscosity suitable for a coating method using, for example, the organic solvent, and is applied on a substrate by a dip coating method, a flow coating method, a roll coating method, or a bar coater method. It is applied by a method such as screen printing or curtain coating, and it is about 60-: The organic solvent contained in the composition is evaporated and dried (temporary drying) at a temperature of LOO ° C. Can be formed. In addition, a resin insulation layer can be formed by applying the composition on a plastic film, drying it, and laminating it on a substrate. After that, the contact-type (or non-contact-type) is selectively exposed to actinic rays through a photomask having a pattern formed thereon, and the unexposed portion is diluted with a dilute alkaline aqueous solution (for example, 0. A resist pattern is formed by development with a 3 to 3% sodium carbonate aqueous solution. Furthermore, for example, by heating to a temperature of about 140 to 180 ° C. and thermosetting, the carboxyl group of the carboxyl group-containing copolymer resin (A) has two or more oxsilane rings in the molecule. The epoxy group of the polyfunctional epoxy resin can react to form a cured coating film excellent in various properties such as heat resistance.

Here, as an irradiation light source for photocuring the coating film, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metalno, or a ride lamp is suitable. In addition, a laser beam or the like can also be used as an exposure active light source for direct drawing.

[0057] Further, as the dilute alkaline aqueous solution used for the development, alkaline aqueous solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, ammonia, amines and the like can be used. Sodium carbonate is preferred.

[0058] A three-dimensional insulating structure can also be formed by repeating coating and volatilization drying twice or more and laminating the coating film. Further, the coated film after development may be heated to a temperature of Tg or more, and the non-turn side wall may be thermally deformed into a smooth taper. Here, exposure and development may be performed every time coating or volatile drying or may be performed at once.

Example

Next, the present invention will be described in detail with reference to examples and comparative examples of the present invention, but it goes without saying that the present invention is not limited to the following examples. In the following, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

<Synthesis Example 1> (Synthesis of carboxyl group-containing copolymer resin A)

In a 2 liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube, diethylene glycol dimethyl ether 900 g and tert-butyl 2-ethyl hexanoate [Nippon Yushi Co., Ltd. Perbutyl 0] 21 4g was charged and the temperature was raised to 90 ° C. 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and latathone modified 2-hydroxyethyl methacrylate represented by the general formula (I) [Daicel PLACCEL FM1] 109. 8g of bis (4-tert-butylcyclohexyl) peroxy dicarbo Nate [Nippon Yushi Co., Ltd. Paryl TCP] 21.4 g was added dropwise to diethylene glycol dimethyl ether over 3 hours and aged for 6 hours to obtain a carboxyl group-containing copolymerized resin (A) solution. The reaction was performed under a nitrogen atmosphere.

[0061] Next, the carboxyl group-containing copolymer resin (A) solution was charged with 3,4-epoxycyclohexylmethyl acrylate [Cyclomer A200 manufactured by Daicel Chemical Industries, Ltd.] 363.9 g, dimethyl benzylamine 3. 6 g and 1.80 g of hydroquinone monomethyl ether were added, and the mixture was heated to 100 ° C and stirred to carry out an epoxy ring-opening addition reaction. 16 hours later, containing 53.8% by mass (non-volatile content) of photosensitive carboxyl group-containing copolymer resin (A) with a solid content of acid value = 108.9 mgKOHZg and weight average molecular weight = 25,000 (in terms of styrene) A solution was obtained. Hereinafter, this reaction solution is referred to as A-1 varnish.

[0062] <Comparative Synthesis Example 1> (Synthesis of carboxyl group-containing resin)

In a flask equipped with a thermometer, stirrer, dropping funnel, and reflux condenser, cresol-type novolac epoxy resin (Epiclon N-680, manufactured by Dainippon Ink & Chemicals, epoxy equivalent = 210) 96.4 g of Levitonole acetate was weighed and melted with hot heat. Next, 0.1 g of idroquinone as a polymerization inhibitor and 2. Og of triphenylphosphine as a reaction catalyst were obtained. This mixture was heated to 95 to 105 ° C., 72 g of acrylic acid was gradually added dropwise, and the mixture was allowed to react for about 16 hours until the acid value became 3. OmgKOHZg or less. The reaction product was cooled to 80 to 90 ° C., and 76. lg of tetrahydrophthalic anhydride was added. By infrared absorption analysis, the absorption peak of acid anhydride (1780 cm ^_1 ) disappeared until about 6 Reacted for hours. To this reaction solution was added 96.4 g of aromatic solvent ibuzole # 150 manufactured by Idemitsu Petrochemical Co., Inc., diluted, and taken out. The carboxyl group-containing photosensitive polymer solution thus obtained had a nonvolatile content of 65% by mass and a solid acid value of 78 mgKOHZg. Hereinafter, this reaction solution is referred to as R-1 varnish.

[0063] Examples 1 to 4 and Comparative Example 1

The compounding ingredients shown in Table 1 using the A-1 varnish and R-1 varnish obtained in the above synthesis example were kneaded with a three-roll mill to obtain a curable resin composition. Table 2 shows the results of characteristic evaluation of each curable composition.

[table 1] table 1

[Table 2]

Table 2

[0064] *: It was strong enough to make ink with high filling.

The performance test methods in Table 2 above are as follows.

[0065] Performance evaluation:

(1) Thermal conductivity

The compositions of the above Examples and Comparative Examples were applied on the entire surface of the test substrate by screen printing so that the dry coating film was about 40 m, and dried at 80 ° C. for 20 minutes. After cooling to room temperature Under reduced pressure using an exposure apparatus (metal nose lamp 7KW2 lamp) manufactured by Oak Manufacturing Co., Ltd., with a Kodak Step Tablet No. 2 exposing the entire surface with an exposure amount of about 6 steps, then 1% NaCO at 30 ° C The aqueous solution was developed for 60 seconds at a spray pressure of 0.2 MPa.

twenty three

[0066] The thermal conductivity of the cured coating film thus obtained at 25 to 125 ° C was measured by a laser flash method.

[0067] (2) Sensitivity

The compositions of the above Examples and Comparative Examples were applied to the entire surface of a glass epoxy substrate by screen printing, dried at 80 ° C. for 20 minutes, allowed to cool to room temperature, and then Kodak Step Tablet No. 2 (21 steps). ) used as a photomask, under reduced pressure at Oak Seisakusho exposure apparatus (Metarunoヽhalide lamp 7KW2 lamp), exposure (200MjZcm 2 in integrating actinometer 365nm UV, and 600MjZcm ²⁾ and, 30. 1% Na CO aqueous solution of C sprayed at 0.2 MPa for 1 minute

twenty three

Development was performed for a while, and the number of steps of the remaining cured coating film was visually confirmed.

[0068] (3) Electrical insulation

Similar to the thermal conductivity measurement described above, using a comb-type electrode B coupon with an IPC B-25 test pattern, a substrate was fabricated under the above conditions, and a bias of 500 V DC was applied to this comb-type electrode, and the insulation resistance The value was measured.

[0069] (4) Acid resistance

Similar to the above-described thermal conductivity measurement, the entire surface was coated on a circuit-formed glass epoxy substrate by screen printing, the substrate was prepared under the above conditions, and the substrate was placed in a 10 vol% sulfuric acid aqueous solution at room temperature for a predetermined time ( After immersion for 10 minutes and 30 minutes, and after washing with water, a peel test using a cellophane adhesive tape was performed to evaluate the resist peeling and discoloration.

[0070] 〇; No change at all

△; Slightly changed

X: The coating film has peeling.

[0071] (5) Water absorption

Similar to the thermal conductivity measurement, the compositions of the above Examples and Comparative Examples were applied to the entire surface of the glass plate whose mass was measured in advance by screen printing, and an evaluation sample was obtained under the above conditions. After cooling this to room temperature, the mass of the evaluation sample was measured. Next, this evaluation service After immersing the sample in pure water at room temperature for 24 hours, the moisture adhering to the surface was wiped off, the mass of the evaluation sample was measured, and the water absorption rate of the cured product was determined by the following formula.

[0072] Water absorption rate = (W2-W1) / (Wl -Wg)

Here, W1 is the mass of the evaluation sample, W2 is the mass of the evaluation sample after water absorption, and Wg is the mass of the glass plate.

[0073] (6) Linear expansion coefficient

Similar to the thermal conductivity measurement described above, the cured product alone is used as an evaluation sample, and a

1 (linear expansion coefficient below Tg) was measured.

[0074] According to the curable resin composition of the present invention, the resulting force shown in Table 2 is also clear, it is possible to fill with a high amount of inorganic filler, resulting in low linear expansion coefficient, high thermal conductivity, It has become possible to provide a resin composition that can be easily reduced in water absorption and can be developed with a dilute aqueous alkali solution.

[0075] It was confirmed that the gasification component released at high temperature was small.

Claims

The scope of the claims

[1] (A) a carboxyl group-containing copolymer resin, (B) a compound having two or more reactive groups that are cured by active energy rays, (C) a photopolymerization initiator, and (D) an inorganic filler. In other words, the alkali-developable curable resin composition is characterized in that the content of the inorganic filler (D) is 65% by mass or more in the solid content.

[2] A compound in which the carboxyl group-containing copolymer resin (A) is represented by the following general formula (I) or (I).

[Chemical 1]

hC—— R ³ — 0-HC—— IT—_ C— 0— H (II)

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkylene group having 2 to 6 carbon atoms, R ³ is an alkylene group having 3 to 3 carbon atoms: LO, and R ⁴ is dihydrochloric acid. The curable resin composition according to claim 1, which is a carboxyl group-containing copolymer resin containing an anhydride residue as a constituent component.

The compound (B) having two or more reactive groups that are cured by the active energy ray is a compound having two or more ethylenically unsaturated bonds, and the photopolymerization initiator (C) is a radical photopolymerization initiator. The curable resin composition according to claim 1 or 2, wherein the composition is an agent.

4. The curable resin composition according to claim 1, wherein the content of the inorganic filler (D) is 80% by mass or more in the solid content. 5.

The curable resin composition according to any one of claims 1 to 4, wherein the inorganic filler (D) has a thermal conductivity of 15 WZm'K or more. [6] The inorganic filler (D) force is oxyaluminum.

V, curable resin composition according to item 1

[7] The curable resin composition according to any one of claims 1 to 6, further comprising (E) a thermosetting component.

[8] The curable resin composition according to [7], wherein the thermosetting component (E) is a polyfunctional epoxy resin having two or more oxysilane rings in the molecule. .

[9] The curable resin composition according to any one of claims 1 to 8, wherein the curable resin composition is insulating.

[10] A cured product obtained by subjecting the curable resin composition according to any one of claims 1 to 9 to irradiation with active energy rays and Z or thermal curing.

11. The cured product according to claim 10, wherein the thermal conductivity is lWZm'K or more.