JPH11214813A - Insulating resin compound for multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating resin compound for a multilayer printed wiring board having an excellent heat resistance and a high adhesive strength between an insulation layer and a conductive layer at a low price. SOLUTION: An insulation resin compound for multilayer printed wiring board with polybutadiene C having epoxy equivalent of 150 to 250 and the end group being hydrogen or hydroxyl group, which comprises a bisphenol type epoxy resin compound at least as a photohardening resin, an ultraviolet ray hardening resin A obtained by reaction between a reactant of unsaturated monocarbonic acid and saturated or unsaturated polybasic acid anhydride, a multifunctional epoxy resin B as a thermal hardening component, a polybutadiene C obtained by turning part of double coupling region remaining in molecules, epoxy compound D and photopolymerization initiator E having both the photohardening component and thermo-hardening component, and a filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating resin composition used for a multilayer printed wiring board, and more particularly to a method of plating a resin insulating layer made of a heat-resistant resin in comparison with a conventional method. The present invention relates to an insulating resin composition for forming a multi-layer printed wiring board having high strength.

[0002]

2. Description of the Related Art In recent years, with the advance of electronic technology, electronic devices such as large-sized computers have been increased in density or operation functions. As a result, multilayer printed wiring boards in which wiring circuits are formed in multiple layers have been spotlighted for the purpose of increasing the density of printed wiring boards.

Conventionally, a typical multilayer printed wiring board is, for example, a multilayer printed wiring board in which an internal circuit is connected and made conductive. However, such a multilayer printed wiring board has a plurality of internal circuits that pass through. Since the connection is conducted through the holes, the wiring circuit becomes too complicated, and it has been difficult to realize high density and high speed.

As a multilayer printed wiring board capable of overcoming such problems, a multilayer printed wiring board in which a conductor pattern and an organic insulating film are alternately built up has recently been developed. There are several means for forming a conductor layer on this organic insulating layer.
Although the conductive pattern is formed by the combined use of the method D and the electroless plating, the formation of the conductor pattern by the PVD method is inferior in productivity and has a problem of increasing the cost.

[0005] Therefore, a method of forming the surface of an insulating layer by electroless plating or electrolytic plating after roughening the surface has become mainstream. However, the multilayer build-up wiring board according to this method has a high reliability such that the plating film may swell when the adhesion between the organic insulating layer and the conductor layer is not sufficient in the step of heating and curing the insulating layer. There was a problem that can not be obtained.

[0006] Recently, as a method for forming an electroless plating film on such an organic insulating film with high reliability, a component soluble in an acid or an oxidizing agent is mixed into a resin insulating layer and dissolved and removed. A method of roughening a surface in contact with electroless plating has been proposed. For example, as described in JP-A-64-47095, a heat-resistant resin insulating layer is used as a matrix, and an epoxy resin soluble in an oxidizing agent is contained in the resin layer.
By mixing a resin such as bismaleimide / triazine resin or polyester resin with a resin or filler insoluble in an oxidizing agent, the surface of the resin insulating layer can be roughened with an oxidizing agent to enhance the anchor effect of electroless plating film formation. Proposed.

In order to further enhance these effects, for example, as described in Japanese Patent Application Laid-Open No. 7-34505, pseudo particles having different sizes of resin particles soluble in an oxidizing agent are used. And mixed with a heat-resistant matrix resin layer.

[0008]

However, in these methods, the heat resistance of the resin particles dissolved in the heat-resistant resin insulating layer with an oxidizing agent or the like is poor, and the oxidizing agent removes the soluble resin on the surface. However, the electroless plating film is formed while the soluble resin in the resin in which the heat-resistant resin insulating layer serves as a matrix remains in the resin as it is. Therefore, the heat resistance of the formed insulating layer depends on the heat resistance of the soluble resin, and as a result, there is a problem that the resin insulating layer has low heat resistance.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a multi-layered printed wiring board having high adhesion between an insulating layer and a conductive layer and excellent heat resistance. An object of the present invention is to provide a conductive resin composition and manufacture a multilayer printed wiring board at low cost.

[0010]

Means for Solving the Problems In order to achieve the above object in the present invention, first, in the invention of claim 1, at least a bisphenol type epoxy resin compound as a photocurable resin and an unsaturated monocarboxylic acid are used. An ultraviolet curable resin (A) obtained by reacting a reactant with a saturated or unsaturated polybasic anhydride, a polyfunctional epoxy resin (B) as a thermosetting component, and a double bond site remaining in the molecule. Containing a polybutadiene (C) partially epoxidized, an epoxy compound (D) having both a photocuring component and a thermosetting component, a photopolymerization initiator (E), and a filler (F). An insulating resin composition for a multilayer printed wiring board, which has a photocurable property and a thermosetting property that can be developed in a solution.

Further, in the invention according to the second aspect, the multifunctional epoxy resin (B) as the thermosetting component is an alicyclic epoxy compound, and the insulating material for a multilayer printed wiring board according to the first aspect. It is a resin composition.

According to the third aspect of the present invention, the polybutadiene (C) in which a part of the double bond site remaining in the molecule is epoxidized has an epoxy equivalent of 150 to 250 and a terminal group of hydrogen or hydroxyl. 2. An insulating resin composition for a multilayer printed wiring board according to claim 1, wherein:

[0013] In the invention according to claim 4, the epoxy compound (D) having both the photo-curing component and the thermosetting component is:
2. The insulating resin composition for a multilayer printed wiring board according to claim 1, which is an acrylate or methacrylate compound having a 3,4-epoxycyclohexylmethyl group.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail. First, an ultraviolet curable resin (A) obtained by reacting a reaction product of a bisphenol type epoxy compound as a photocurable resin and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic anhydride as described in the present invention. At
Specific examples of the bisphenol component include bis (4-hydroxyphenyl) ketone, bis (4-hydroxy-3,
5- (dimethylphenyl) ketone, bis (4-hydroxy-3,5-dichlorophenyl) ketone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy-3,5-dichlorophenyl) ) Sulfone, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) methane, bis (4
-Hydroxy-3,5-dichlorophenyl) methane, bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dimethylphenyl) hexafluoropropane, bis (4-hydroxy-3,5 dichlorophenyl) hexafluoropropane,
Bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxy-3,5-dimethylphenyl) dimethylsilane, bis (4-hydroxy-3,5-dichlorophenyl) dimethylsilane, 2,2-bis (4-hydroxyphenyl) propane, 2 , 2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, bis (4-hydroxyphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) Ether, bis (4-hydroxy-3,5 dichlorophenyl) ether and the like.

Further, specific examples of the unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, and cinnamic acid.

Specific examples of the above-mentioned saturated or unsaturated polybasic anhydrides include maleic anhydride, succinic anhydride,
Dibasic such as itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endmethylenetetrahydrophthalic anhydride, chlorendic anhydride, methyltetrahydrophthalic anhydride; Aromatic polycarboxylic anhydrides such as melitic acid, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride; and other accompanying compounds such as 5- (2,5-dioxotetrahydrofuryl) -3
Polymethyl carboxylic anhydride derivatives such as -methyl-3-cyclohexene-1,2 dicarboxylic anhydride can be used.

Further, as the polybutadiene (C) in which a part of the double bond remaining in the molecule described in the present invention is epoxidized, the amount of epoxy in the polybutadiene molecule can be arbitrarily set by using peracetic acid. Further, those having a hydrogen or hydroxyl group at the terminal group can be used.
If the epoxy equivalent is less than 150, the strength of the insulating layer itself decreases due to excessive cross-linking inside the insulating layer, and if it exceeds 250, the curing of the insulating layer becomes insufficient and sufficient heat resistance is obtained. Since it cannot be obtained, the epoxy equivalent is desirably 150 to 250.

Further, as the photopolymerization initiator (E) constituting the insulating resin composition for a multilayer printed wiring board of the present invention, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylamino Propiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone,
Benzophenones such as acetophenones, benzophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, benzoin, benzoin methyl ether, benzoin isopropyl ether,
Benzoin ethers such as benzoin isobutyl ether, benzyl dimethyl ketal, thioxanthone, 2
Sulfur compounds such as 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2 Anthraquinones such as 3, diphenylanthraquinone, azobisisobutyronitrile,
Organic peroxides such as benzoyl peroxide and cumene peroxide; 2-mercaptobenzimidazole;
And thiol compounds such as 2-mercaptobenzoxazole and 2-mercaptobenzothiazole. These compounds may be used in combination of two or more. In addition, although it does not act as a photopolymerization initiator by itself, a compound that increases the ability of the photopolymerization initiator by using it in combination with the above compounds can also be added. Such compounds are effective when used in combination with benzophenone, for example, and include tertiary amines such as triethanolamine.

The filler (F) described in the present invention may be, for example, an organic filler such as a fluororesin, a polyimide resin, a benzoguanamine resin, or silica, talc, alumina, clay, calcium carbonate, titanium oxide, sulfuric acid, or the like. An inorganic filler such as barium may be used and may be added.

Further, in the insulating resin composition, if necessary, an epoxy group curing accelerator, a thermal polymerization inhibitor, a plasticizer, a leveling agent, a defoaming agent, an ultraviolet absorber, a flame retardant, etc. Additives, coloring pigments and the like can be added.

Next, a method for manufacturing a multilayer printed wiring board according to the present invention will be specifically described. First, the above-mentioned photosensitive resin insulating layer is formed on a substrate on which a conductive circuit is formed. As the substrate, for example, a plastic substrate, a ceramic substrate, a metal substrate, a film substrate, or the like can be used.Specifically, a glass epoxy substrate, a bismaleimide-triazine substrate, an aluminum substrate, an iron substrate, a polyimide substrate, or the like is used. can do.

As a method for forming the resin insulating layer on the substrate on which the conductor circuit is formed, a solution of the photosensitive resin composition having photosensitivity is prepared by, for example, a roller coating method.
A dip coating method, a spray coating method, a spinner coating method, a curtain coating method, a slot coating method, a method of applying by various means such as a screen printing method, or a resin film obtained by processing the above-mentioned insulating resin composition into a film. It is also possible to apply a method of doing so.

The preferable thickness of the resin insulating layer in the present invention is usually about 20 to 100 μm, but it can be larger when particularly high insulating properties are required.

Subsequently, on the resin insulating layer obtained above,
The exposed portions are cured by irradiating ultraviolet rays through a negative film, and then a so-called alkali development is performed using a weak alkaline aqueous solution to elute the unexposed portions.

As the ultraviolet light, an ultra-high pressure mercury lamp,
Light emitted from a lamp such as a high-pressure mercury lamp or a metal halide lamp can be used, and is suitably used for curing an exposed portion.

The alkaline aqueous solution includes an aqueous solution of sodium carbonate, an aqueous solution of sodium hydrogen carbonate, an aqueous solution of diethanolamine, an aqueous solution of triethanolamine,
An aqueous solution of ammonium hydroxide or an aqueous solution of sodium hydroxide can be used, and is preferably used for elution of an unexposed portion.

Next, after alkali development, it is desirable to carry out an epoxy curing treatment by heating in order to improve heat resistance and alkali resistance. In the insulating resin composition of the present invention, by performing the heat treatment, not only the durability against strong alkaline water is remarkably improved, but also various properties such as adhesion to glass, metal such as copper, heat resistance, surface hardness and the like. Properties are also improved.

Subsequently, after the surface of the resin insulating layer which has been subjected to the heat treatment as described above is subjected to surface roughening treatment using an acid or an oxidizing agent, electroless plating and electrolytic plating are performed.
A multilayer printed wiring board is manufactured by forming a conductor circuit.

The method of electroless plating is preferably, for example, at least one of electroless copper plating, electroless nickel plating, electroless gold plating, electroless silver plating, and electroless tin plating. is there. It should be noted that, after the electroless plating is performed, a different type of electroless or electrolytic plating may be performed, or a solder may be coated.

According to the present invention, a conductor circuit can be formed by various methods conventionally used for a printed wiring board. For example, after a substrate is subjected to electroless and electrolytic plating, A method of etching a circuit, a method of directly forming a circuit when performing electroless plating, and the like can be applied.

By using the above-described insulating resin composition for a multilayer printed wiring board of the present invention, a resin insulating layer having excellent heat resistance can be formed, and the adhesion to an electroless plating film can be improved. As a result, a multilayer printed wiring board having excellent reliability can be easily and inexpensively provided.

[0032]

Next, the present invention will be described more specifically with reference to examples. <Example 1> An acid value of about 207 (mg KOH / mg) obtained by reacting bisphenol A type epoxy acrylate (Ripoxy VR-90, manufactured by Showa Polymer Co., Ltd.) with phthalic anhydride
g), 200 parts by weight of an ultraviolet curable resin, 50 parts by weight of epoxy polybutadiene rubber PB4700 (manufactured by Daicel Chemical), 60 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate M-100 (manufactured by Daicel Chemical), and an average particle diameter of 3 μm. 43 parts by weight of fine silica powder, leveling agent BY
1.4 parts by weight of K110 (by Big Chemie), dispersant BY
0.407 parts by weight of K 307 (manufactured by Big Chemie) and 9.6 parts by weight of a photopolymerization initiator Luciln TPO (manufactured by BASF) were added to a 3-methoxybutyl acetate solvent, stirred, kneaded with three rolls, and exposed to light. A solution of an insulating resin composition having a property was obtained.

Next, the solution of the insulating resin composition having photosensitivity obtained above was applied to a degreased and washed copper-clad glass epoxy substrate to a thickness of about 40 μm using a slot coater and dried. , 150 through photomask
The substrate was exposed to light at a pressure of mJ / cm ² and developed with a triethanolamine developer at 30 ° C. for 1 minute to remove unexposed portions. Thereafter, heat curing treatment was performed at 200 ° C. for 1 hour using a drying oven to form a resin insulating layer.

Subsequently, the board on which the resin insulating layer is formed is subjected to a copper plating process on an ordinary printed board to a thickness of about 25 μm.
m of copper plating was obtained to obtain a printed wiring board.

<Example 2> Bisphenol A type epoxy acrylate (Lipoxy VR-90, manufactured by Showa Polymer Co., Ltd.)
Acid value of about 207 obtained by reacting
(MgKOH / g) UV curable resin 200 parts by weight, epoxy polybutadiene rubber PB4700 (manufactured by Daicel Chemical) 35 parts by weight, 3,4-epoxycyclohexylmethyl methacrylate M-100 (manufactured by Daicel Chemical) 60
Parts by weight, 16 parts by weight of epoxy resin EHPE3150 (manufactured by Daicel Chemical Industries, Ltd.), fine silica powder 43 having an average particle diameter of 3 μm 43
Parts by weight, leveling agent BYK 110 (by Big Chemie)
1.4 parts by weight, dispersant BYK 307 (by Big Chemie)
0.44 parts by weight, photopolymerization initiator Luciln TPO (BASF
9.6 parts by weight of a 3-methoxybutyl acetate solvent was added thereto, and the mixture was stirred and kneaded with a three-roll mill to obtain a photosensitive insulating resin composition solution.

Thereafter, a resin insulating layer and copper plating were formed using the same materials and operations as in Example 1 to obtain a printed wiring board.

<Example 3> Bisphenol A type epoxy acrylate (Lipoxy VR-90, manufactured by Showa Polymer Co., Ltd.)
Acid value of about 207 obtained by reacting
(MgKOH / g) UV curable resin 200 parts by weight, epoxy polybutadiene rubber PB4700 (manufactured by Daicel Chemical) 25 parts by weight, 3,4-epoxycyclohexylmethyl methacrylate M-100 (manufactured by Daicel Chemical) 60
By weight, 26 parts by weight of epoxy resin EHPE3150 (manufactured by Daicel Chemical Industries, Ltd.), fine silica powder 43 having an average particle diameter of 3 μm 43
Parts by weight, leveling agent BYK 110 (by Big Chemie)
1.4 parts by weight, dispersant BYK 307 (by Big Chemie)
0.44 parts by weight, photopolymerization initiator Luciln TPO (BASF
9.6 parts by weight of a 3-methoxybutyl acetate solvent was added thereto, followed by stirring and kneading with a three-roll mill to obtain a solution of a photosensitive insulating resin composition.

Thereafter, a resin insulating layer and copper plating were formed using the same materials and operations as in Example 1 to obtain a printed wiring board.

<Example 4> Bisphenol A type epoxy acrylate (Lipoxy VR-90, manufactured by Showa Polymer Co., Ltd.)
Acid value of about 207 obtained by reacting
(MgKOH / g) UV resin 200 parts by weight, epoxy polybutadiene rubber PB4700 (manufactured by Daicel Chemical Industries, Ltd.)
15 parts by weight, 60 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate M-100 (manufactured by Daicel Chemical), 36 parts by weight of epoxy resin EHPE3150 (manufactured by Daicel Chemical), 43 parts by weight of silica fine powder having an average particle diameter of 3 μm, Leveling agent BYK 110 (by Big Chemie)
1.4 parts by weight, dispersant BYK 307 (by Big Chemie)
0.44 parts by weight, photopolymerization initiator Luciln TPO (BASF
9.6 parts by weight of a 3-methoxybutyl acetate solvent was added thereto, followed by stirring and kneading with a three-roll mill to obtain a solution of a photosensitive insulating resin composition.

Thereafter, a resin insulating layer and copper plating were formed by using the same materials and operations as in Example 1 to obtain a printed wiring board.

Example 5 Bisphenol A type epoxy acrylate (Lipoxy VR-90, manufactured by Showa Kogyo KK)
Acid value of about 207 obtained by reacting
(MgKOH / g) UV resin 200 parts by weight, epoxy polybutadiene rubber PB4700 (manufactured by Daicel Chemical Industries, Ltd.)
5.0 parts by weight, 60 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate M-100 (manufactured by Daicel Chemical), 47 parts by weight of epoxy resin EHPE3150 (manufactured by Daicel Chemical), 43 parts by weight of silica fine powder having an average particle diameter of 3 μm Part, leveling agent BYK 110 (by Big Chemie)
1.4 parts by weight, dispersant BYK 307 (by Big Chemie)
0.44 parts by weight, photopolymerization initiator Luciln TPO (BASF
9.6 parts by weight of a 3-methoxybutyl acetate solvent was added thereto, followed by stirring and kneading with a three-roll mill to obtain a solution of a photosensitive insulating resin composition.

Thereafter, a resin insulating layer and copper plating were formed by using the same materials and operations as in Example 1 to obtain a printed wiring board.

Comparative Example 1 Bisphenol A type epoxy acrylate (Lipoxy VR-90, manufactured by Showa Polymer Co., Ltd.)
Acid value of about 207 obtained by reacting
(MgKOH / g) 200 parts by weight of an ultraviolet curable resin,
3,4-epoxycyclohexylmethyl methacrylate
60 parts by weight of M-100 (manufactured by Daicel Chemical), 52 parts by weight of epoxy resin EHPE3150 (manufactured by Daicel Chemical), 43 parts by weight of fine silica powder having an average particle diameter of 3 μm, and a leveling agent BYK 110 (manufactured by Big Chemie) 1.4 Parts by weight,
0.44 parts by weight of dispersant BYK307 (manufactured by Big Chemie) and 9.6 of photopolymerization initiator Luciln TPO (manufactured by BASF)
A part by weight of a 3-methoxybutyl acetate solvent was added and stirred, and then kneaded with a three-roll mill to obtain a solution of a photosensitive insulating resin composition.

Thereafter, a resin insulating layer was formed and copper plating was formed by using the same materials and operations as in Example 1 to obtain a printed wiring board.

The insulating resin compositions for multilayer printed wiring boards obtained in Examples 1 to 5 and Comparative Example 1 were evaluated for the following items, and are shown in Table 1. 1) Resolution (μm): The resolution (μm) of the round via pattern, which is obtained by visually observing that the via extends to the lowermost layer of the resin insulating layer. 2) Peel strength (Kg / cm): The peel strength between the resin insulating layer and the copper plating is 10 mm in width according to JIS4681.
Copper plating of Tensilon tensile tester RTC-1250
(Orientec). 3) Solder heat resistance: 25 × 5 according to JIS6481
The copper laminate of 0 mm was immersed in a solder bath at 260 ° C. for 20 seconds, and it was visually determined that there was no blister. 4) Insulation: Surface resistance and volume resistance were measured and determined using a super insulation resistance / microammeter TR8601 (Takeda Riken Kogyo) according to JIS6481.

[0046]

[Table 1]

As shown in Table 1 above, in Examples 1 to 5, the adhesion between the resin insulating layer and the copper plating layer increased with an increase in the addition amount of the component (C). However, by adding the hydrophobic component (C), the resolution becomes inferior. In Examples 4 and 5, however, by adjusting the amount of addition,
The adhesion strength of the plating increases without a decrease in resolution. In Examples 1 to 5, solder heat resistance and insulation were not impaired. Also,
In Comparative Example 1, there was no problem with the resolution, solder heat resistance, and insulation, but the adhesion between the insulating layer and the copper plating layer was reduced.

[0048]

As described above, the present invention has the following effects. That is, an ultraviolet curable resin (A) obtained by reacting at least a reaction product of a bisphenol type epoxy resin compound as a photocurable resin with an unsaturated monocarboxylic acid and a saturated or unsaturated polybasic anhydride,
An epoxy compound (D) having both a polyfunctional epoxy resin (B) as a thermosetting component, a polybutadiene (C) in which a part of a double bond site remaining in the molecule is epoxidized, and a photocuring component and a thermosetting component ), A photopolymerization initiator (E) and a filler (F), and a polybutadiene (C)
However, since the insulating resin composition for a multilayer printed wiring board having an epoxy equivalent of 150 to 250 and a terminal group being hydrogen or a hydroxyl group is used, a resin having excellent heat resistance can be obtained by using the insulating resin composition. An insulating layer can be formed, the adhesion to an electroless plating film can be improved, and a highly reliable multilayer printed wiring board can be easily and inexpensively provided.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shinji Kawachi 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd.

Claims (4)

[Claims] An ultraviolet curable resin (A) obtained by reacting at least a reaction product of a bisphenol type epoxy resin compound as a photocurable resin with an unsaturated monocarboxylic acid and a saturated or unsaturated polybasic anhydride. And a polyfunctional epoxy resin (B) as a thermosetting component, a polybutadiene (C) in which a part of the double bond site remaining in the molecule is epoxidized, and an epoxy compound having both a photocuring component and a thermosetting component (D), a photopolymerization initiator (E), and a filler (F), and have photocurability and thermosetting properties that can be developed in a dilute alkaline solution. Resin composition. 2. The insulating resin composition for a multilayer printed wiring board according to claim 1, wherein the polyfunctional epoxy resin (B) as the thermosetting component is an alicyclic epoxy compound. 3. The polybutadiene (C) in which a part of the double bond site remaining in the molecule is epoxidized has an epoxy equivalent of 150 to 250 and a terminal group is hydrogen or a hydroxyl group. Item 4. The insulating resin composition for a multilayer printed wiring board according to Item 1. 4. The multilayer according to claim 1, wherein the epoxy compound (D) having both the photocuring component and the thermosetting component is an acrylate or methacrylate compound having a 3,4-epoxycyclohexylmethyl group. Insulating resin composition for printed wiring boards.