JP2001094261A - Interlayer insulating material for multilayer printed wiring boards - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer insulating material for multilayer printed wiring boards whereby the adhesion of plating films can be improved, without deteriorating the coating property, the electric insulation and the heat resistance. SOLUTION: The interlayer insulating material for multilayer printed wiring boards contains an organic binder component and a filler component for forming micropits formed by the roughening process. The filler component is prepared by compounding a spherical porous inorganic filler of 3-10 μm in mean grain size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer insulating material for a multilayer printed wiring board, and more particularly to an interlayer insulating material suitably used for a multilayer printed wiring board in which conductive circuit layers and resin insulating layers are alternately built up. .

[0002]

2. Description of the Related Art A multilayer printed wiring board by a build-up method is manufactured by sequentially forming (building up) a resin insulating layer and a conductor circuit pattern on a conductor of a circuit-formed wiring board. In the multilayer printed wiring board based on this build-up method, the electrical connection between the conductor layers adjacent inside and outside is made via holes, and the electrical connection between the outermost conductor layers is made through holes.

[0003] In a multilayer printed wiring board manufactured by such a build-up method, the adhesion between the interlayer insulating resin and the conductor greatly affects the reliability of the wiring board. A method has been proposed. For example, a curable resin containing an organic filler such as rubber particles or polymer particles or an inorganic filler such as calcium carbonate in an ultraviolet curable resin and / or a thermosetting resin (matrix resin) as an interlayer insulating resin. Compositions have been proposed.

According to these proposals, it is true that the surface of a cured film made of a curable resin composition containing a filler is chemically treated with a roughening agent to thereby oxidatively decompose the cured resin (matrix resin). As a result, the rubber particles are exposed, or the organic filler or the inorganic filler is dissolved, and the surface of the cured film becomes uneven, so that the adhesion to the plating film formed on the cured film is improved.

However, in the method of forming a convex portion of rubber particles by eluting a part of the cured resin (matrix resin), the adhesion of the rubber particles to the matrix resin becomes unstable because the matrix resin is eluted. On the contrary, there is a problem that the adhesion between the interlayer insulating resin and the conductor is deteriorated depending on the conditions of the roughening treatment.

In the method of forming a concave portion by dissolving an organic filler such as an epoxy resin or a polyester resin which is soluble in a roughening agent such as an oxidizing agent, the organic filler is not dissolved in the oxidizing agent or the like but is contained in the layer. Will remain. Due to the difference in heat resistance between the cured resin (matrix resin) and the cured resin (matrix resin), the cured product generally depends on the characteristics of the organic filler having low heat resistance. The problem was that it was formed.

Further, in the method of forming the concave portions by dissolving the inorganic filler on the surface of the cured film by a roughening treatment, it is necessary to increase the content of the inorganic filler in order to form the concave portions uniformly and at a high density. However, when a large amount of an inorganic filler dissolved by the roughening treatment, such as calcium carbonate, is added to the curable resin composition, the viscosity of the composition becomes high, the fluidity becomes poor, and only the composition having poor applicability is obtained. There is a possibility that various problems, such as a problem that it cannot be obtained and a decrease in electrical insulation, may occur.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and its main object is to reduce the applicability, electric insulation and heat resistance. Another object of the present invention is to provide an interlayer insulating material for a multilayer printed wiring board which can improve the adhesion to a plating film.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies for realizing the above-mentioned object, and as a result, have arrived at an invention having the following content as a gist configuration. That is, in order to solve the above problem, the interlayer insulating material for a multilayer printed wiring board of the present invention, an organic binder component, an interlayer insulating material containing a filler component for forming fine recesses by roughening treatment, as the filler component And a spherical porous inorganic filler having an average particle size of 3 to 10 μm. Here, as the organic binder component, any resin composition that can satisfy the required characteristics of the interlayer insulating material for a multilayer printed wiring board can be used regardless of a photosensitive resin, a thermosetting resin, or a thermoplastic resin. . More preferably, a photosensitive resin composition containing at least (A) a photosensitive prepolymer, (B) a photopolymerization initiator, (C) a photopolymerizable monomer as a diluent and / or an organic solvent, or (a) A thermosetting resin composition containing an epoxy resin, (b) an epoxy resin curing agent, and (c) an organic solvent as essential components is used. It is particularly preferable that the photosensitive resin composition further comprises (D) a finely divided epoxy compound. More preferably, the spherical porous inorganic filler is preferably made of silica, and the compounding amount of the spherical porous inorganic filler is 5 to 100 parts by weight based on 100 parts by weight of the resin solid content of the interlayer insulating material. Preferably, the spherical porous inorganic filler has an oil absorption of 50 to 800 ml / 100 g, preferably 100 to 200 ml / 100 g.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The interlayer insulating material for a multilayer printed wiring board of the present invention is characterized in that a spherical porous inorganic filler having an average particle size of 3 to 10 μm is used as a filler which can be removed by a roughening agent. This spherical filler can be easily removed with a roughening agent. When a normal amorphous filler is used, the filler is removed by dissolving and removing the alkali-soluble matrix resin from the surface layer in an alkaline solution, so that an incompletely removed filler may remain on the interlayer resin surface. is there. There was a problem that the adhesion strength with the conductor could not be improved due to the residual filler. In this regard, according to the configuration of the present invention, the alkaline solution penetrates into the micropores of the spherical porous filler, and the matrix resin is uniformly removed along the spherical surface of the filler, and the filler is spherical and escapes from the resin surface. As a result, a fine uneven surface exhibiting a good anchor effect is formed on the interlayer resin surface. As a result, the adhesion to the conductor can be significantly improved.

As such a spherical porous inorganic filler, any one can be used as long as it can be removed by a roughening agent such as potassium permanganate or chromic acid. Particularly, in the present invention, silica is preferably used in that the insulating property is not impaired. The average particle size of this spherical porous inorganic filler is
3 to 10 μm. The reason for this is that it is difficult to adjust the average particle diameter to less than 3 μm because particles smaller than 3 μm are difficult to classify. On the other hand, considering the thickness of the interlayer insulating layer and the formation of a fine pattern, the average particle diameter should be 10 μm or less. This is because it is preferable. The compounding amount of this spherical porous inorganic filler is
5-10 based on 100 parts by weight of resin solid content of interlayer insulating material
0 parts by weight. The reason for this is that if the amount is less than 5 parts by weight, a roughened surface exhibiting a sufficient anchoring effect cannot be obtained, so that the peel strength of the conductor cannot be improved. On the other hand, if it exceeds 100 parts by weight, it cannot be uniformly dispersed in the resin. It is. The oil absorption of the spherical porous filler is 50 to 800 ml / 100 g. The reason for this is that if the porosity is less than 50 ml / 100 g, the effect of the present invention cannot be obtained because the porosity is not sufficient.
If the amount exceeds 00 ml / 100 g, the porous state cannot be maintained.

Next, any roughening agent may be used as long as it penetrates into the porosity of the spherical porous inorganic filler and uniformly decomposes or dissolves the matrix resin from the outer peripheral surface of the filler. Is also good. For example, although different depending on the resin component of the matrix used, sodium hydroxide, potassium hydroxide, and the like as alkaline roughening agents, and potassium permanganate, potassium dichromate, ozone, and hydrochloric acid as acidic roughening agents. , Sulfuric acid, nitric acid, hydrofluoric acid and the like, and N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethylsulfoxide, methoxypropanol, dimethylformamide (DMF) and the like as organic solvents.

Next, the organic binder component constituting the interlayer insulating material for a multilayer printed wiring board of the present invention will be described. The organic binder component is not particularly limited as long as it is a resin composition that can satisfy the required characteristics of the interlayer insulating material for a multilayer printed wiring board, such as a photosensitive resin composition or a thermosetting resin composition. , A thermoplastic resin composition, or a mixture or composite thereof. In particular, in the present invention, (A) a photosensitive prepolymer, (B) a photopolymerization initiator, (C) a photosensitive resin composition containing a photopolymerizable monomer and / or an organic solvent as a diluent, or (a) A thermosetting resin composition containing an epoxy resin, (b) an epoxy resin curing agent, and (c) an organic solvent as essential components is used. The photosensitive resin composition preferably further comprises (D) a finely divided epoxy compound.

The photosensitive prepolymer (A) includes:
For example, a compound having at least two ethylenically unsaturated bonds in one molecule is preferable, and (a-1) a total esterified product of an epoxy group generated by an esterification reaction between an epoxy compound and an unsaturated monocarboxylic acid; -2) a reaction product of a secondary hydroxyl group of the above all esterified product (a-1) with a saturated or unsaturated polybasic acid anhydride, and (a-3) a diisocyanate having one hydroxyl group in one molecule (Meta)
A reaction product obtained by reacting a reaction product with an acrylate with a secondary hydroxyl group of the above-mentioned all-esterified product (a-1), (a-4) esterification of an epoxy compound with an unsaturated monocarboxylic acid A partial esterified product of an epoxy group generated by the reaction, (a-5) the partial esterified product (a
-4) a reaction product of a secondary hydroxyl group with a saturated or unsaturated polybasic anhydride, and (a-6) a diisocyanate and 1
A reaction product obtained by reacting a reaction product with a (meth) acrylate having one hydroxyl group in the molecule and a secondary hydroxyl group of the above partially esterified product (a-4) is exemplified. Such a photosensitive prepolymer is disclosed in
Since it is described in detail in JP-A-141904, refer to the official gazette for details. When the photosensitive prepolymer (A) is solid or semi-solid at room temperature, it can be used for both contact and non-contact exposure systems. When it is liquid at room temperature, it is mainly used for non-contact exposure system. Is done. The photosensitive prepolymer (A) is used by selecting at least one of the above various prepolymers according to the exposure method.

As the photosensitive prepolymer (A), those which can be alkali-developed from the viewpoint of environmental pollution are preferable, and from the viewpoint of stability of the photosensitive prepolymer, all the esterified products of unsaturated monocarboxylic acid are used. Is preferred,
Further, from the viewpoint of photocurability, an esterified product of an unsaturated monocarboxylic acid using acrylic acid (and / or methacrylic acid) is preferable. Therefore, as the photosensitive prepolymer (A), all esterified products of the novolak type epoxy compound with (meth) acrylic acid, and further, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, succinic acid, itaconic acid, Reaction products obtained by reacting polybasic acid anhydrides such as chlorendic acid, methylhexahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, methyltetrahydrophthalic acid, trimellitic acid, pyromellitic acid and benzophenonetetracarboxylic acid ( a-2) is particularly preferred.

Representative examples of the photopolymerization initiator (B) include benzoins such as benzoin, benzyl, benzoin methyl ether and benzoin isopropyl ether and zonzoin alkyl ethers; acetophenone, 2,2- Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4
-(Methylthio) phenyl] -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-
1- (4-morpholinophenyl) -butanone-1,
Acetophenones such as N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone,
-Chloroanthraquinone, 2-amylanthraquinone,
Anthraquinones such as 2-aminoanthraquinone;
Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone;
Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,
Benzophenones such as 4'-bisdiethylaminobenzophenone; and xanthones can be used alone or in combination of two or more. further,
Such a photopolymerization initiator (B) may be a commonly used photopolymerization initiator such as benzoic acid esters such as ethyl-4-dimethylaminobenzoate and 2- (dimethylamino) ethylbenzoate, or tertiary amines such as triethylamine and triethanolamine. And one or more photosensitizers can be used in combination. The preferred range of the amount of the photopolymerization initiator (B) used is 0.2 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the photosensitive prepolymer (A). is there.

Next, as the diluent (C), a photopolymerizable vinyl monomer and / or an organic solvent can be used.
Representative photopolymerizable vinyl monomers include 2
Hydroxyalkyl acrylates such as -hydroxyethyl acrylate and 2-hydroxybutyl acrylate; mono- or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol;
Acrylamides such as N-dimethylacrylamide and N-methylolacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanate Polyhydric alcohols such as nurate or polyhydric acrylates of these ethylene oxide or propylene oxide adducts; phenoxy acrylates, bisphenol A diacrylates, and acrylates of these phenols such as ethylene oxide or propylene oxide adducts; Glycidyl ether such as glycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc. Acrylates ethers; and the like melamine acrylate, and / or the corresponding methacrylates of the above acrylates.

On the other hand, organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether Glycol ethers such as dipropylene glycol monoethyl ether and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate and acetic acid ester of the above glycol ethers; ethanol, propanol, ethylene glycol, propylene glycol and the like Alcohols such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha There are, the photosensitive prepolymer (A) and the compatibility is good and does not dissolve the particulate epoxy compound (D) is preferred.

The diluent (C) as described above is used alone or as a mixture of two or more, and the preferred range of the amount is 20 to 100 parts by weight of the photosensitive prepolymer (A). It is 300 parts by weight, preferably 30 to 200 parts by weight. The purpose of use of the diluent is, in the case of a photopolymerizable vinyl monomer, to dilute the photosensitive prepolymer to make it easy to apply, and to enhance photopolymerizability, and in the case of an organic solvent, This is for dissolving and diluting the photosensitive prepolymer, thereby applying it as a liquid, and then drying it to form a film. Therefore, depending on the diluent to be used, either a contact type or a non-contact type in which a photomask is brought into contact with a coating film is used.

Next, the finely divided epoxy compound (D) must be dispersed in the photosensitive prepolymer (A) in a finely divided form, and must be solid or semi-solid at room temperature. Those which do not dissolve in the photosensitive prepolymer (A) and the diluent (C) to be used during kneading, and / or have a solubility within a range that does not adversely affect the photosensitivity and developability. It is preferable that these conditions are satisfied. Heterocyclic epoxy resins such as TEPIC (registered trademark for triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd., and Araldite PT810 manufactured by Ciba-Geigy, and Yuka Shell Co., Ltd. And a bixylenol type epoxy resin such as YX-4000. These epoxy resins have a high melting point (for example, the melting point of TEPIC is 90
１２５125 ° C., about 105 ° C. for YX-4000), and it is preferable because it does not dissolve even at the heating temperature (usually 60-85 ° C.) for drying the coating film. In addition, Blemmer D manufactured by NOF Corporation
A diglycidyl phthalate resin such as GT, a biphenol type epoxy resin such as YL-6056 manufactured by Yuka Shell Co., Ltd., and a tetraglycidyl xylenoyl ethane resin such as ZX-1063 manufactured by Toto Kasei can be used. Particularly preferred are the above-mentioned heterocyclic epoxy resins.

The epoxy compound (D) is obtained by pulverizing the epoxy compound by a conventional method and / or kneading with another composition component such as the photosensitive prepolymer (A) by, for example, a kneader such as a roll mill. Fine particles can be obtained by breaking and dispersing, and they can be used alone or in combination of two or more. The preferred range of the amount used is such that the mixing ratio of the photosensitive prepolymer (A) and the epoxy compound (D) is 50 to 95:50 to 5 (parts by weight) (based on 100 parts by weight of the photosensitive prepolymer). About 5 to 100 parts by weight), more preferably 60 to 90:40 to 10. If the ratio exceeds 50:50, the photosensitivity and the solubility of the unexposed portion in the developing solution are reduced. On the other hand, if the ratio is less than 95: 5, various properties as an interlayer insulating material such as heat resistance cannot be obtained. Further, the particle size (the particle size of the particles dispersed in the composition) is suitably 50 μm or less, and preferably 30 μm or less. Particle size 50μ
In the case where m is exceeded, the passability of the screen is deteriorated in the application by the screen printing, so that a pinhole is easily generated on the surface of the coating film. .

In place of the sparingly soluble epoxy compound (D), bisphenol A type epoxy resin,
Hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, novolak type epoxy resin, novolak type epoxy resin of bisphenol A, glyoxal type epoxy resin, amino group containing epoxy resin, rubber modified epoxy resin , Dicyclopentadiene phenolic epoxy resin, silicone-modified epoxy resin, ε-caprolactone-modified epoxy resin, and (meth) of these epoxy compounds
An epoxy compound having two or more epoxy groups in one molecule, which is soluble in the diluent (C) such as a partially esterified product of acrylic acid, is used for photosensitivity and solubility of an unexposed portion in a developer. It can be used within a range where there is no practical problem in terms of surface. The preferred range of the amount of the soluble epoxy compound (S) to be used is as follows.
D: S = 40-100: 60-0, preferably 6
0 to 100: 40 to 0, more preferably 70 to 10
0:30 to 0, and the compounding ratio to the photosensitive prepolymer (A) is 75:25 or less, more preferably 80:20 or less. If the ratio exceeds 75:25, in the case of the alkali developing type, the solubility of the unexposed portion in the developing solution is reduced, and the undeveloped portion tends to be generated. The film is likely to fall off and blisters, making it difficult to use practically.
The combined use of a soluble epoxy compound has an effect of improving some of the properties as an interlayer insulating material, for example, plating resistance.

The photosensitive thermosetting resin composition thus obtained contains a hydroxyl group and / or a hydroxyl group in the photosensitive prepolymer (A).
Or, since a carboxyl group is contained and the hydroxyl group and / or carboxyl group in the photosensitive prepolymer (A) functions as a curing agent for the epoxy resin, it can be sufficiently used as an interlayer insulating material without further using a curing agent for an epoxy resin. Function. Further, as the photopolymerization initiator (B), the amino group-containing photopolymerization initiator used for improving photosensitivity,
When a photosensitizer is contained, the curing of the epoxy compound (D) is further promoted by the effects of the photopolymerization initiator and the amino group in the photosensitizer. However, in order to further improve properties such as adhesion, chemical resistance, heat resistance, and electroless plating resistance, it is preferable to further use the following epoxy resin curing agent (b) in combination.

Examples of the curing agent or curing accelerator (b) for epoxy resin include dicyandiamide, melamine, acetoguanamine, benzoguanamine, 3,9-bis [2- (3,5-diamino-2, 4,
Guanamine such as 6-triazaphenyl) ethyl] 2,4,8,10tetraoxaspiro [5,5] undecane and derivatives thereof, and organic acid salts and epoxy adducts thereof can be preferably used. These compounds are conventionally known to have adhesiveness and rust-preventive property to copper, and not only act as a curing agent for epoxy resin, but also can contribute to prevention of discoloration of copper on a printed wiring board. . Imidazole derivatives; diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, cyclohexylamine, m-xylylenediamine, 4,4'-diamino-3,3'-diethyldiphenylmethane, diethylenetriamine, tetraethylenepentamine, N-aminoethyl Polyamines such as piperazine, isophoronediamine, urea, urea derivatives, polybasic hydrazide, organic acid salts and / or epoxy adducts thereof; amine complexes of boron trifluoride; trimethylamine;
Triethanolamine, N, N-dimethyloctylamine, N, N-dimethylaniline, N-benzyldimethylamine, pyridine, N-methylpyridine, N-methylmorpholine, hexamethoxymethylmelamine, 2,4,6
-Tris (dimethylaminophenol), N-cyclohexyldimethylamine, tetramethylguanidine, m-
Tertiary amines such as aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolak and alkylphenol novolak; organic phosphines such as tributylphosphine, triphenylphosphine, tris-2-cyanoethylphosphine; tri-n- Phosphonium salts such as butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride, phenyltributylammonium chloride and benzyltrimethylammonium bromide; Diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroanti And cationic photopolymerization catalysts such as 2,4,6-triphenylthiopyrylium hexafluorophosphate and Irgacure 261 manufactured by Ciba-Geigy; styrene-maleic acid resin; and such known and commonly used curing agents. And one or two curing accelerators
More than one kind can be used as a mixture with the compound. The amount of the epoxy resin curing agent (b) used is usually sufficient in a quantitative ratio, and is, for example, 0.1% by weight or more and 10% by weight or less based on the photosensitive thermosetting resin composition according to the present invention. Is preferred.

Although the above-mentioned thermosetting component may be mixed in advance with the photosensitive resin composition, it tends to thicken before application to a circuit board blank. In use, it is desirable to use a mixture of both.
That is, a curing agent solution mainly composed of the epoxy compound (D) and the photosensitive prepolymer (A) mainly,
It is preferable to form a two-part composition of a base solution containing the curing agent for epoxy resin (b) and the like, and to mix these before use. Further, the above-mentioned photopolymerizable monomer, filler, coloring pigment and the like can be mixed with an organic solvent solution of the epoxy compound (D) as the thermosetting component.

The photosensitive thermosetting resin composition of the present invention may contain barium sulfate, barium titanate, silicon oxide powder, fine powdered silicon oxide, if necessary, for the purpose of improving properties such as adhesion and hardness. Known inorganic fillers such as amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder can be compounded, and the compounding ratio is 0% of the photosensitive thermosetting resin composition. ６０60% by weight, preferably 5-40
% By weight. If necessary, phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and other commonly used coloring agents, hydroquinone, hydroquinone monomethyl ether, tert-butyl catechol, Pyrogallol, phenothiazines and other commonly known thermal polymerization inhibitors, asbestos, orbenes (organo bentonite),
Benton, known and conventional thickeners such as montmorillonite,
Defoamers such as silicone-based, fluorine-based, and polymer-based defoamers and / or
Alternatively, known and commonly used additives such as a leveling agent, an imidazole-based, a thiazole-based, a triazole-based, and an adhesion-imparting agent such as a silane coupling agent can be blended.

For the purpose of enhancing the impact resistance of the cured coating film, a copolymer of an ethylenically unsaturated compound such as an acrylate ester or a polyhydric alcohol and a saturated or unsaturated polybasic acid compound may be used. Known and commonly used binder resins such as synthesized polyester resins, polyester (meth) acrylates synthesized from polyhydric alcohols and saturated or unsaturated polybasic acid compounds and glycidyl (meth) acrylate, and polyhydric alcohols Known and commonly used photosensitive oligomers such as urethane (meth) acrylates synthesized from polyisocyanates and diisocyanates and hydroxyl group-containing (meth) acrylates can also be used in a range that does not affect various properties as an interlayer insulating material. However, among the components described above, with respect to known and commonly used binder resins such as copolymers of ethylenically unsaturated compounds such as acrylates and polyester resins, the photosensitive thermosetting resin composition contains an organic solvent. Similar to the case where a soluble epoxy resin is used, it is estimated that copolymers having no photosensitive group or a commonly used binder resin are dissolved in a state in which they are entangled with the photosensitive prepolymer (A). Therefore, the amount used is preferably 10% by weight or less (about 5% by weight or less of the whole composition) based on the photosensitive prepolymer (A).

The developing solution for forming the interlayer insulating material pattern after exposing the photosensitive thermosetting resin composition through a photomask varies depending on the selection of the photosensitive prepolymer (A). As, cyclohexanone, xylene, tetramethylbenzene, butyl cellosolve, butyl carbitol, propylene glycol monomethyl ether, cellosolve acetate, propanol,
Propylene glycol, trichloroethane, trichloroethylene, modified trichloroethane (Eterna IR manufactured by Asahi Kasei Kogyo Co., Ltd., Three One E manufactured by Toa Gosei Chemical Industry Co., Ltd.)
XR, Kanden Triethane SR manufactured by Kanto Denka Kogyo Co., Ltd.
-A, an organic solvent such as RESISOLV V-5) manufactured by Asahi Glass Co., Ltd., and / or an alkali such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, and amines. An aqueous solution and / or a surfactant aqueous solution can be used.

Next, as the epoxy resin (a) constituting the thermosetting resin composition, known epoxy resins can be used. For example, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type Epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, aliphatic cyclic epoxy resin, epoxy resin containing triazine nucleus, biphenyl epoxy resin, brominated epoxy resin, dimer acid modified epoxy resin, trihydroxyphenylmethane epoxy Resins, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, tetraphenylolethane type epoxy resin, heterocyclic epoxy resin and the like. As the epoxy resin curing agent (b) and the organic solvent (c) to be mixed together with the epoxy resin, the same ones as described for the photosensitive resin composition can be used, and the same applies to the mixing ratio thereof. is there. Further, various additives described above can be blended with the thermosetting resin composition as long as the desired properties and characteristics are not violated.

As the thermoplastic resin, known and commonly used ones can be used, for example, cellulose derivatives such as methylcellulose, ethylcellulose and hydroxyethylcellulose, polyolefins such as ethylene-vinyl acetate copolymer, polyethylene and polypropylene, and olefinic hydroxyl groups. Lactone-modified polymer in which a lactone is added to the hydroxyl group of the olefinic hydroxyl group-containing polymer or the amino group of the amino resin, or a lactone to the hydroxyl group or amino group of a monomer having both a hydroxyl group or an amino group and an unsaturated group in one molecule. Homopolymer of added lactone-modified monomer, copolymer of lactone-modified monomer and monomer having another unsaturated group, copolymerized (meth) acrylate resin, polypropylene carbonate resin, acetal resin, ABS resin Fluororesin, polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, various resins such as polystyrene can be used.

[0031]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but it is needless to say that the present invention is not limited to the following examples. In the following, “parts” and “%” are all based on weight unless otherwise specified.

Example 1 (Preparation of photosensitive resin composition) Each component was blended in the following blending ratio and kneaded using a three-roll mill to obtain a photosensitive resin composition. A photosensitive prepolymer (equimolar reaction product of cresol novolac type epoxy resin and acrylic acid,
100 parts of a resin solid to which 0.5 mol of tetrahydrophthalic anhydride is added per unit) 100 parts of 2-methyl 1- (4- (methylthio) phenyl) -2
-Morpholino-propan-1-one: 10 parts, dipropylene glycol monomethyl ether: 20
Parts: Dicyandiamide: 1 part Silicone defoamer: 0.5 part Spherical porous silica: 20 parts Dipentaerythritol hexaacrylate: 15
Parts: Epoxy resin: 25 parts As the above spherical porous silica, Asahi Glass Co., Ltd. Sunsphere (trade name) H-31 was used. Specific physical properties are as follows. Average particle size: 3 μm, specific surface area: 800 m ² / g, pore volume: 1 ml / g, pore diameter: 50 °, oil absorption: 150 ml
/ 100g

Comparative Example 1 A photosensitive resin composition was obtained in the same manner as in Example 1 except that spherical porous silica was not blended. The components were blended at the following blend ratios, and kneaded using a three-roll mill to prepare a photosensitive resin composition. A photosensitive prepolymer (equimolar reaction product of cresol novolac type epoxy resin and acrylic acid,
Resin solid content to which 0.5 mol of tetrahydrophthalic anhydride is added per unit): 100 parts 2-methyl 1- (4- (methylthio) phenyl) -2
-Morpholino-propan-1-one: 10 parts, dipropylene glycol monomethyl ether: 20
Parts:-Dicyandiamide: 1 part-Silicone-based antifoaming agent: 0.5 parts-Dipentaerythritol hexaacrylate: 15
Parts, epoxy resin: 25 parts

Comparative Example 2 A photosensitive resin composition was obtained in the same manner as in Example 1 except that amorphous silica was used instead of spherical porous silica. The components were blended at the following blend ratios, and kneaded using a three-roll mill to prepare a photosensitive resin composition. A photosensitive prepolymer (equimolar reaction product of cresol novolac type epoxy resin and acrylic acid,
100 parts of a resin solid to which 0.5 mol of tetrahydrophthalic anhydride is added per unit) 100 parts of 2-methyl 1- (4- (methylthio) phenyl) -2
-Morpholino-propan-1-one: 10 parts, dipropylene glycol monomethyl ether: 20
Parts: Dicyandiamide: 1 part Silicone antifoaming agent: 0.5 part Amorphous silica: 20 parts Dipentaerythritol hexaacrylate: 15
Parts, epoxy resin: 25 parts

Preparation of Test Pieces The photosensitive resin compositions obtained in Example 1 and Comparative Examples 1 and 2 were each coated on a glass epoxy resin substrate with a PET 100 mesh screen to a thickness of 50 μm. The coating was dried at 80 ° C. for 60 minutes in a hot-air circulation drying oven to form a coating film. Applying a negative film on the substrate, exposing a predetermined pattern as one of the spray pressure 2 kg / cm ²
It was developed with a wt% Na ₂ CO ₃ aqueous solution to form a resin insulating pattern. This substrate was heated at 160 ° C. for 60 minutes and thermally cured to prepare a test piece. Furthermore, in order to roughen the surface of the cured coating film, 1% aqueous solution of potassium permanganate at 70 ° C.
After treatment for 0 minutes, the surface was neutralized and washed. Then, the test pieces after the roughening treatment prepared using the photosensitive resin compositions obtained in Example 1 and Comparative Examples 1 and 2 were referred to as “test piece a” and “test pieces b1 and b2”, respectively. And
Next, the substrate subjected to the surface roughening treatment is immersed in a palladium catalyst solution, and then the catalyst is activated. The substrate is immersed in an electroless plating bath to perform electroless plating.
m of copper plating was formed. Then, a test piece prepared by using the photosensitive resin composition obtained in Example 1 and Comparative Examples 1 and 2 and subjected to copper plating was subjected to “test piece A” and “test piece B1 and B2 ". The following performance tests were performed on each test piece.

Adhesion of Copper-Plated Conductor The peel strength of the copper-plated conductor of the test piece A was about 1.0 kg / cm. On the other hand, when the peel strength of the copper-plated conductor was examined for the test pieces B1 and B2, both were about 0.6 kg / cm.

Observation of the surface of the test piece The surfaces of the test piece a and the test pieces b1 and b2 were
Observation was performed using a scanning electron microscope (SEM). Then
With respect to the test piece a, the filler was satisfactorily removed and uniform and high-density fine irregularities were formed on the surface of the insulating layer. On the other hand, as for the test piece b1, minute irregularities were sparsely formed on the surface of the insulating layer. In the test piece b2, fine irregularities were sparsely formed on the surface of the insulating layer, and a large number of amorphous silica remained.

Example 2 (Preparation of Thermosetting Resin Composition) Each component was blended in the following proportions and kneaded using a three-roll mill to prepare a thermosetting resin composition. -Cresol novolak type epoxy resin (manufactured by Yuka Shell Epoxy): 84 parts,-Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy): 16 parts,-Spherical porous silica (Asahi Glass Co., Ltd.) Manufactured): 60 parts, dipropylene glycol monomethyl ether: 10
Parts:-As an epoxy curing agent, a phenolic resin (manufactured by Meiwa Kasei Co., Ltd.): 50 parts;-An imidazole curing agent (manufactured by Shikoku Chemical Industry Co., Ltd.): 5
Parts: diethylene glycol monoethyl ether acetate: 30 parts

Comparative Example 3 (Preparation of Thermosetting Resin Composition) Each component was blended at the following blending ratio and kneaded using a three-roll mill to prepare a thermosetting resin composition. -Cresol novolak type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.): 84 parts-Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.): 16 parts-Spherical silica (manufactured by Admatechs, average) Particle size 3μ
m): 60 parts Dipropylene glycol monomethyl ether: 10
Parts:-As an epoxy curing agent, phenol resin (manufactured by Meiwa Kasei Co., Ltd.): 50 parts-Imidazole curing agent (manufactured by Shikoku Chemical Industry Co., Ltd.): 5 parts-Diethylene glycol monoethyl ether acetate: 30 parts

Each of the thermosetting resin compositions obtained in Example 2 and Comparative Example 3 is applied by screen printing to a substrate on which a circuit is formed in advance, and is heated and cured (150 ° C. × 30 minutes).
After that, a roughening treatment was performed in the same manner as in “Preparation of test piece”, and then electroless copper plating and electrolytic copper plating were performed. When the peel strength of the copper-plated conductor was measured in accordance with JIS C 6481 for each of the obtained test pieces, it was 1.2 kg / cm in Example 2 and 0.8 kg / cm in Comparative Example 3. . It should be noted that no change was observed in the electrical insulation of any of the resin insulating layers before and after the surface roughening treatment.

[0041]

As described above, according to the present invention, the following effects can be obtained by using a spherical porous inorganic filler as a filler. (1) The filler is satisfactorily removed, uniform and high-density fine irregularities are formed on the surface of the insulating layer, and a sufficient anchor effect can be obtained. Therefore, there is provided an interlayer insulating material for a multilayer printed wiring board capable of improving the adhesion to a plating film without causing a decrease in applicability, electrical insulation and heat resistance. (2) Since uniform and high-density minute irregularities are obtained on the surface of the insulating layer, the amount of filler used can be reduced as compared with the conventional case. (3) In the case of a photosensitive resin composition, the use of a spherical porous filler also provides an effect that resolution is not impaired.

Claims (7)

[Claims] 1. An interlayer insulating material for a multilayer printed wiring board containing an organic binder component and a filler component for forming fine recesses by roughening treatment, wherein the filler component is a spherical porous inorganic filler having an average particle diameter of 3 to 10 μm. An interlayer insulating material characterized by comprising: 2. As the organic binder component, at least (A) a photosensitive prepolymer, (B) a photopolymerization initiator,
The interlayer insulating material according to claim 1, further comprising (C) a photopolymerizable monomer and / or an organic solvent as a diluent. 3. The interlayer insulating material according to claim 2, further comprising (D) a finely divided epoxy compound. 4. An organic binder component comprising, as essential components, (a) an epoxy resin, (b) an epoxy resin curing agent, and (c) an organic solvent.
2. The interlayer insulating material according to item 1. 5. The interlayer insulating material according to claim 1, wherein the spherical porous inorganic filler is made of silica. 6. The compounding amount of the spherical porous inorganic filler is 5 to 10 based on 100 parts by weight of the resin solid content of the interlayer insulating material.
The interlayer insulating material according to any one of claims 1 to 5, wherein the amount is 0 parts by weight. 7. The interlayer insulating material according to claim 1, wherein the spherical porous inorganic filler has an oil absorption of 50 to 800 ml / 100 g.