JP2000096022A - Radiation-polymerizable electrical insulating resin composition and multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of forming electrical insulation layer improved in insulation resistance and roughenable without the need of any mechanically grinding means by including a specific compound, an epoxy resin, a specific rubber, and a phenolic resin. SOLUTION: This composition is obtained by including (A) 100 pts.wt. of a radiation-polymerizable compound (pref. ultraviolet-polymerizable one such as epoxy acrylate), (B) 20-60 pts.wt. of an epoxy resin (e.g. a polyfunctional one; when this composition is intended to impart itself with flame retardancy, it is preferable to use a halogenated epoxy resin such as a brominated epoxy resin), (C) 5-30 pts.wt. of an epoxy-modified acrylonitrile-butadiene rubber, (D) 5-30 pts.wt. of a phenolic resin, and (E) as necessary, an inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a radiation-polymerizable insulating resin composition and a multilayer printed wiring board.

[0002]

2. Description of the Related Art Recently, a multilayer printed wiring board manufactured by a build-up method has attracted attention as a method of manufacturing a multilayer printed wiring board because the wiring density can be increased. The build-up method is a method of sequentially stacking circuits and insulating layers. That is, the first layer formed on the insulating layer
An insulating layer is formed on the circuit described above, and a second circuit is formed thereon. The second circuit is regarded as the first circuit, and the formation of the insulating layer and the formation of the second circuit are repeated as necessary to form a multilayer. Usually, the first circuit formed first is formed by performing circuit processing on a metal-clad laminate.

[0003] As a method of forming the second circuit, the first method is used.
A method of laminating a metal foil on the circuit of the above via an insulating layer and etching the metal foil, and a method of forming the metal foil by plating on the insulating layer formed on the first circuit. Yes, all have been put to practical use.

In a multilayer printed wiring board, it is necessary to form an electrical connection between a first circuit and a second circuit, that is, an interlayer connection. This interlayer connection is called a via hole. Then, as the name implies, it is formed by forming an interlayer connection hole in an insulating layer between the first circuit and the second circuit, and depositing a conductor in the interlayer connection hole by plating.

In the method of forming the second circuit on the insulating layer by plating, a radiation-polymerizable insulating resin composition is used as a material for the insulating layer, and the radiation ( (Ultraviolet rays are usually used.) Irradiation is performed to polymerize compounds other than the masked portion among the compounds polymerized by the radiation irradiation contained in the radiation-polymerizable insulating resin composition to make them insoluble in a developing solution and masked. A portion of the insulating material is dissolved and removed (developed) with a developer to form an interlayer connection hole. Since the photographic technique is used in this way, this method is called a photo method.

Hereinafter, the steps of the photo method will be described with reference to FIG. (A) Using a metal-clad laminate as a starting material, performing circuit processing on the metal-clad laminate,
(See FIG. 1A). (B) A radiation polymerizable insulating resin composition layer 3a is formed on the insulating substrate 2 on which the first circuit 1 is formed (see FIG. 1B). (C) The radiation-polymerizable insulating resin composition layer 3a is irradiated with radiation while masking a portion where the interlayer connection hole 4 is to be formed, and is developed to form the interlayer connection hole 4 (see FIG. 1C). .
Thereafter, heating is performed to advance the curing of the radiation-polymerizable insulating resin composition layer 3a to form the insulating layer 3. Then, the surface of the insulating layer 3 is roughened by treatment with a roughening solution. (D) Plating is performed on the surface of the insulating layer 3 and in the interlayer connection hole 4 to form a plating layer 5 (see FIG. 1D). (E) The circuit processing is performed on the plating layer 5 to form the second circuit 6 (see FIG. 1E). Hereinafter, the second circuit 6 is regarded as the first circuit 1 (b) to
By repeating the step (e) a required number of times, further multilayering can be achieved.

The insulating layer 3 is required to have insulation and heat resistance required for a printed wiring board, and to have a surface that improves the adhesion of the plating layer 5. For this reason, the radiation polymerizable insulating resin composition used for forming the insulating layer 3 includes a compound polymerizable by irradiation, an epoxy resin, and a carboxylic acid-modified crosslinked acrylonitrile butadiene rubber as essential components. Was used. The epoxy resin mainly acts on the insulation and heat resistance of the insulating layer 3, and the carboxylic acid-modified crosslinked acrylonitrile butadiene rubber mainly acts on the adhesion between the insulating layer 3 and the plating layer 5.

[0008]

However, the insulating layer 3 formed using such a radiation-polymerizable insulating resin composition has, for example, an insulation layer having a thickness of 30 μm and an insulation resistance of about 10 GΩ. . In addition, since the surface of the insulating layer 3 is not easily roughened by the roughening solution and the roughening unevenness is easily generated, it is necessary to treat the insulating layer 3 with the roughening solution after partially shaving the surface of the insulating layer 3 by a mechanical polishing means. was there. Examples of the mechanical polishing means include a buff roll, a belt sander, and the like.
In some cases, large polishing scratches remained. Such a large polishing scratch may cause problems such as disconnection or short-circuit of the wiring when forming the fine wiring, which hinders the formation of the fine wiring, so that high-density wiring becomes impossible.

Therefore, the present invention provides a radiation-polymerizable insulating resin capable of improving the insulation resistance of an insulating layer and forming an insulating layer which can be roughened without using mechanical polishing means. It is intended to provide a composition. Another object of the present invention is to provide a multilayer printed wiring board having a high insulation resistance of an insulating layer and capable of high-density wiring.

[0010]

Means for Solving the Problems The invention according to claim 1 comprises a compound polymerizable by irradiation with radiation, an epoxy resin,
A radiation-polymerizable insulating resin composition comprising an epoxy-modified acrylonitrile-butadiene rubber and a phenol resin as essential components.

The epoxy-modified acrylonitrile-butadiene rubber has an epoxy group in the molecule, and both the epoxy-modified acrylonitrile-butadiene rubber and the epoxy resin react with the phenol resin to cure three-dimensionally by crosslinking. For this reason, since the structure derived from acrylonitrile-butadiene rubber is contained in the skeleton, the structure is easily roughened by the roughening liquid. Therefore, the surface of the insulating layer can be roughened without using mechanical polishing.

The invention described in claim 2 is the first invention.
A multilayer printed wiring board comprising an interlayer insulating layer formed by using the radiation-polymerizable insulating resin composition described in 1. above.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a radiation polymerizable insulating resin composition will be described. As the compound polymerized by irradiation with radiation, a compound polymerized by irradiation with radiation can be used, and there is no particular limitation. A compound that is polymerized by ultraviolet irradiation is preferable because irradiation can be easily performed. Examples of such a compound include urethane acrylate, polyester acrylate, epoxy acrylate, and phthalic acid-modified epoxy acrylate. Among them, epoxy acrylate is preferred from the viewpoint of the heat resistance of the insulating layer 3. In addition to the compound polymerized by irradiation with radiation, a photopolymerization initiator is blended if necessary. Examples of the photopolymerization initiator include, but are not particularly limited to, known photopolymerization initiators such as benzylalkyl ketals such as benzyldimethyl ketal and sulfonium salts such as triphenylsulfonium hexafluoroantimonate. The blending amount of the photopolymerization initiator is not particularly limited, and is appropriately selected according to the type and amount of the compound to be polymerized by irradiation with radiation.

Examples of the epoxy resin include known polyfunctional epoxy resins. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, Hydantoin type epoxy resins, isocyanurate type epoxy resins and the like can be mentioned. A halogenated epoxy resin to which halogen such as bromine is added, or a hydrogenated epoxy resin to which hydrogen is added may be used. These epoxy resins may be used alone or in combination of two or more as needed. When it is necessary to make the insulating layer 3 flame-retardant, it is preferable to mix a halogenated epoxy resin, for example, a brominated epoxy resin.

As the epoxy-modified acrylonitrile-butadiene rubber, known epoxy-modified acrylonitrile-butadiene rubber can be used, and there is no particular limitation. Commercial products of epoxy-modified acrylonitrile butadiene rubber include DT-8208 (trade name) of Daito Sangyo Co., Ltd. As the phenol resin, a known phenol resin can be used, and there is no particular limitation.

The epoxy resin, the epoxy-modified acrylonitrile-butadiene rubber and the phenol resin are 20 to 60 parts by weight of the epoxy resin, 5 to 30 parts by weight of the epoxy-modified acrylonitrile-butadiene rubber, and phenol resin based on 100 parts by weight of the compound polymerized by irradiation with radiation. 5-3
It is preferred to be blended in the range of 0 parts by weight. If the epoxy resin is less than 20 parts by weight, the insulating property of the insulating layer 3 tends to decrease, and if it exceeds 60 parts by weight, the formability of the interlayer connection hole 4 tends to deteriorate. If the amount of the epoxy-modified acrylonitrile-butadiene rubber is less than 5 parts by weight, the adhesion to the second circuit tends to decrease, and if it exceeds 30 parts by weight, the workability when forming the insulating layer 3 tends to decrease. If the amount of the phenolic resin is less than 5 parts by weight, the formability of the interlayer connection hole 4 tends to be poor, and if the amount exceeds 30 parts by weight, the roughening property when the insulating layer 3 is roughened with a roughening liquid is reduced. There is a tendency. From this, 25 to 40 parts by weight of the epoxy resin and 10 parts by weight of the epoxy-modified acrylonitrile-butadiene rubber
More preferably, it is blended in a range of from about 25 parts by weight to about 25 parts by weight of the phenol resin.

In addition, when necessary for reinforcing mechanical strength, inorganic fillers such as alumina, fine powder silica, aluminum hydroxide, zirconium silicate and talc can be blended.

Next, the production of a multilayer printed wiring board will be described in the order of steps. The first first circuit is formed by performing circuit processing on a metal-clad laminate. As the metal-clad laminate used here, a known metal-clad laminate can be used, and there is no particular limitation. A single-sided or double-sided metal-clad laminate is appropriately selected and used depending on the configuration of the multilayer printed wiring board to be manufactured. A copper-clad laminate using copper foil is used as the metal foil, and a glass cloth base epoxy resin is preferably used as the material of the insulating substrate from the viewpoint of heat resistance. In the field of printed wiring boards, copper-clad laminates using copper foil are used as metal foils, and thus copper-clad laminates will be described below.

The method of forming the first circuit by performing circuit processing on the copper-clad laminate can be a known method commonly used in the manufacture of printed wiring boards, and is not particularly limited. For example, the first circuit 1 is formed on one surface (see FIG. 1A) or both surfaces of the insulating substrate 2 by etching copper foil.

Next, the surface of the first circuit 1 is roughened. In this step, the surface is oxidized with an alkaline aqueous solution of sodium hypochlorite to form copper oxide needle-like crystals, and the formed copper oxide needle-like crystals are immersed in an aqueous dimethylamine borane solution and reduced. And there is no particular limitation.

Next, the insulating substrate 2 on which the first circuit 1 is formed
The radiation polymerizable insulating resin composition layer 3a is formed thereon (see FIG. 1B). As a method for forming the radiation-polymerizable insulating resin composition layer 3a, a method in which a varnish of the radiation-polymerizable insulating resin composition is applied by a method such as screen printing, roll coating, curtain coating, or the like. Or a sheet shape, and laminating and laminating them. Further, the thickness of the radiation-polymerizable insulating resin composition layer 3a is not particularly limited, and is usually appropriately selected in the range of 20 to 200 μm.

Next, the radiation-polymerizable insulating resin composition layer 3a is irradiated with radiation while masking the portion where the interlayer connection hole 4 is to be formed, and is developed to form the interlayer connection hole 4. Development can be performed by a known method, and there is no particular limitation. For example, a method in which a 10 to 50% by weight aqueous alkali solution of a water-soluble organic solvent such as butoxyethanol is used as a developer and the developer is sprayed or immersed in the developer may be used. After the development, heating is performed to advance the curing of the radiation polymerizable insulating resin composition layer 3a to form the insulating layer 3 (FIG. 1 (c)).
reference). The heating condition at this time is not particularly limited as long as the radiation-polymerizable insulating resin composition layer 3a is appropriately cured.

Subsequently, the surface of the insulating layer 3 is roughened by a treatment with a roughening solution. The surface of the insulating layer 3 can be roughened by a known method such as immersion in an alkali solution of potassium permanganate, and there is no particular limitation.

Next, the film is immersed in an aqueous solution of stannous chloride in hydrochloric acid to perform a sensitizing treatment for attaching tin ions, and a sensitizing treatment for attaching palladium.
The sensitization treatment is performed by immersion in a palladium complex type sensitizer. The palladium complex type sensitizer is a sensitizer mainly containing palladium chloride and a complexing agent which reacts with palladium chloride to form a palladium ion complex. As complexing agents, ethylamines, for example,
Monoethylamine, diethylamine and the like, propylamines such as isopropylamine, diisopropylamine, propylamine and the like, butylamines such as
Examples include amine complexing agents such as t-butylamine and diisobutylamine, and amide complexing agents such as formamide, dimethylformamide, diethylformamide, dimethylacetamide, and dimethylacrylamide. These may be used alone or, if necessary, in combination of two or more.

Pure water is added to the complexing agent and palladium chloride,
Further sensitization of a palladium complex type can be obtained by making it more alkaline. Such palladium complex type sensitizers are commercially available products, for example, manufactured by Hitachi Chemical Co., Ltd .;
AS-101 (trade name) or the like can be used.

Next, by immersing in an electroless plating solution, electroless plating having a thickness of 0.3 to 1.5 μm is deposited thereon, and then electroplated to form a plating layer 5 ( FIG. 1D). As the electroless plating solution used for the electroless plating, a known electroless plating solution can be used, and there is no particular limitation. Also, the electroplating can be performed by a known method, and there is no particular limitation.

Next, circuit processing is performed on the plating layer 5 by the same method as that for forming the first circuit 1 to form a second circuit.
And the interlayer connection between the first circuit 1 and the second circuit 6 is formed (see FIG. 1E).

The second circuit thus formed is:
Hereinafter, a multilayer printed wiring board having a larger number of layers can be manufactured by repeating the steps after the first circuit surface roughening assuming that the circuit is the first circuit.

[0029]

Example 1 Preparation of radiation polymerizable insulating resin composition An acid anhydride-added epoxy acrylate (acid value 72 mg KO)
H / mg, manufactured by Nippon Kayaku Co., Ltd., using PCR-1050 (trade name), 40 parts (parts by weight, the same applies hereinafter), cresol novolac type epoxy resin (epoxy equivalent: 198 g /
eq, 45 parts of bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, Yuka Shell Epoxy Co., Ltd., EP-828 (trade name) using ESCN-195 (trade name) manufactured by Sumitomo Chemical Co., Ltd.) ) 5 parts, terminal epoxy-modified acrylonitrile butadiene rubber (DT-8208 (trade name) manufactured by Daito Sangyo Co., Ltd.) 10
Parts, 10 parts of o-cresol novolak type phenol resin (PSF-2803 (trade name) manufactured by Gunei Chemical Industry Co., Ltd.) and triphenylsulfonium hexafluoroantimonate (photopolymerization initiator, manufactured by Union Carbide Co., Ltd., UVI -6974 (trade name) was used to prepare a radiation-polymerizable insulating resin composition.

Preparation of Two-Layer Printed Wiring Board (a) Single-sided copper-clad laminate of glass cloth base epoxy resin (copper foil thickness: 18 μm, manufactured by Hitachi Chemical Co., Ltd., MCL-E
-67 (trade name) was used to form a first circuit. Next, an aqueous solution containing 5 g / l of sodium hydroxide and 30 g / l of sodium hypochlorite was added at 70 ° C. for 2 hours.
For 1 minute to oxidize the conductor surface of the first circuit, followed by a 5 g / l aqueous solution of dimethylamine borane (pH = 1).
The first circuit surface was roughened by reducing the oxidized first circuit surface by immersion in 3) for 1 minute. (B) Next, the radiation-polymerizable insulating resin composition prepared above was converted into a 70% by weight solution of 1-acetoxy-2-ethoxyethane on the first circuit, and the thickness after drying by roll coating was 30 μm. And apply at 70 ° C for 20
Dried for minutes. (C) Next, a portion to be a hole for interlayer connection is masked and irradiated with ultraviolet rays so that the exposure amount becomes 2000 mJ / cm ² , 10% by weight of sodium hydroxide, 50% by weight of butoxyethoxyethanol, and the remaining water. The developer consisting of
The mixture was heated to 0 ° C., immersed in the mixture for 2 minutes, and developed to form a hole for interlayer connection. Then at 150 ° C for 1
By heating for a time, the radiation-polymerizable insulating resin composition was cured to form an insulating layer.

Subsequently, a roughening solution was prepared by dissolving sodium permanganate and sodium hydroxide in a ratio of 70 g of sodium permanganate and 40 g of sodium hydroxide per liter of pure water, and the roughening solution was heated to 60 ° C. The surface of the insulating layer was roughened by heating and immersing it for 5 minutes. (D) Next, 30 g of stannous chloride per liter of pure water
And 300 ml of concentrated hydrochloric acid in a solution of stannous chloride and concentrated hydrochloric acid for 3 minutes, and then a sensitizer of a palladium complex type (HAS-101 manufactured by Hitachi Chemical Co., Ltd.)
(Using trade name) at room temperature for 10 minutes, followed by rinsing with water to perform a sensitization treatment with a palladium complex.
Subsequently, heat treatment was performed at 150 ° C. for 30 minutes. Thereafter, an electroless copper plating solution (CU, manufactured by Hitachi Chemical Co., Ltd.)
ST-2000 (trade name)) for 30 minutes,
After washing with water, electroplating copper sulfate to a thickness of 20 μm
Was formed. (E) The plating layer is annealed by heating at a temperature of 160 ° C. for 1 hour, and then the steps of forming an etching resist, etching and removing the etching resist are performed by a conventional method to form a second circuit and an interlayer connection. A two-layer printed wiring board was produced.

Example 2 40 parts of an acid anhydride-added epoxy acrylate (same as in Example 1), brominated novolak type epoxy resin (using BREN-105 (trade name) manufactured by Nippon Kayaku Co., Ltd.)
45 parts, bisphenol A type epoxy resin (same as in Example 1) 5 parts, terminal epoxy-modified acrylonitrile butadiene rubber (same as in Example 1) 15 parts, o-cresol novolac type phenol resin (same as Example 1) 15) and 3 parts of triphenylsulfonium hexafluoroantimonate (same as in Example 1) were blended to prepare a radiation-polymerizable insulating resin composition. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Example 3 40 parts of an acid anhydride-added epoxy acrylate (same as in Example 1) and a cresol novolak type epoxy resin (epoxy equivalent: 220 g / eq, manufactured by Asahi Denka Kogyo KK, K
40 parts of RM-2650 (trade name), 7 parts of bisphenol A type epoxy resin (same as in Example 1), 20 parts of acrylonitrile butadiene rubber modified with terminal epoxy (same as in Example 1), resole resin (Hitachi) HP-180R ((trade name) used) manufactured by Kasei Kogyo Co., Ltd. 10
Parts and 3 parts of triphenylsulfonium hexafluoroantimonate (the same as in Example 1) were blended to prepare a radiation-polymerizable insulating resin composition. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Example 4 40 parts of an acid anhydride-added epoxy acrylate (the same as in Example 1), 55 parts of a cresol novolak type epoxy resin (the same as in Example 3), and bisphenol A type epoxy resin (the same as in Example 1) 5 parts, terminal epoxy-modified acrylonitrile butadiene rubber (same as in Example 1) 20 parts, resole resin (same as in Example 3) 15
Parts and 3 parts of triphenylsulfonium hexafluoroantimonate (the same as in Example 1) were blended to prepare a radiation-polymerizable insulating resin composition. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Example 5 40 parts of an acid anhydride-added epoxy acrylate (the same as in Example 1), 55 parts of a cresol novolak type epoxy resin (the same as in Example 3), and bisphenol A type epoxy resin (the same as in Example 1) 5 parts, epoxy-terminated acrylonitrile butadiene rubber (same as in Example 1) 15 parts, resole resin (same as in Example 3) 10
Parts and 3 parts of triphenylsulfonium hexafluoroantimonate (the same as in Example 1) were blended to prepare a radiation-polymerizable insulating resin composition. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Example 6 40 parts of an acid anhydride-added epoxy acrylate (the same as in Example 1), 40 parts of a cresol novolak type epoxy resin (the same as in Example 3), and bisphenol A type epoxy resin (the same as in Example 1) 10 parts, terminal epoxy-modified acrylonitrile butadiene rubber (same as in Example 1) 25 parts, resole resin (same as in Example 3) 20
Parts and 3 parts of triphenylsulfonium hexafluoroantimonate (the same as in Example 1) were blended to prepare a radiation-polymerizable insulating resin composition. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Comparative Example 1 o-cresol novolak type epoxy acrylate (epoxy equivalent 190 g / eq, manufactured by Shin-Nakamura Chemical Co., Ltd., E
A-4400 (trade name)) 80 parts, terminal carboxylic acid-modified acrylonitrile butadiene rubber (Nippon Synthetic Rubber Co., Ltd., use PNR-1H (trade name)) 20 parts,
Crosslinked acrylonitrile butadiene rubber modified with terminal carboxylic acid (XER-91 (trade name) manufactured by Nippon Synthetic Rubber Co., Ltd.)
5 parts, resole resin (same as in Example 3) 1
5 parts, alkylphenol resin (H-2400 (trade name) manufactured by Hitachi Chemical Co., Ltd., 3 parts) and benzyl dimethyl ketal (photopolymerization initiator, manufactured by Ciba Geigy,
A radiation polymerizable insulating resin composition was prepared by mixing 7 parts of I-651 (trade name). Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

Comparative Example 2 The radiation-polymerizable insulating resin composition prepared in Comparative Example 1 was used, and in step (c), baffle polishing was additionally performed before roughening with a roughening solution. In the same manner as in the above, a two-layer printed wiring board was produced.

Comparative Example 3 40 parts of o-cresol novolac type epoxy acrylate (same as Comparative Example 1), 40 parts of acid anhydride-added epoxy acrylate (same as Example 1), acrylonitrile butadiene rubber modified with carboxylic acid terminal (comparative) 20 parts of the same as in Example 1, 20 parts of a terminal carboxylic acid-modified crosslinked acrylonitrile butadiene rubber (the same as in Comparative Example 1), 15 parts of a resole resin (the same as in Example 3), and an alkylphenol resin (the same as in Comparative Example 1) 3), 7 parts of benzyldimethyl ketal (same as in Comparative Example 1) and 10 parts of aluminum hydroxide (H-42M (trade name) manufactured by Showa Denko KK) were mixed to form a radiation-polymerizable insulating resin composition. Was prepared. Thereafter, a two-layer printed wiring board was produced in the same manner as in Example 1.

COMPARATIVE EXAMPLE 4 The procedure of Example 1 was repeated except that the radiation-polymerizable insulating resin composition prepared in Comparative Example 3 was used, and in step (c), buffling was additionally performed before roughening with a roughening solution. In the same manner as in the above, a two-layer printed wiring board was produced.

In Examples 1, 2, 3, 4, 5, and 6 and Comparative Examples 1, 2, 3, and 4, the state of the surface of the insulating layer was examined before step (d). As a result, it was confirmed that the samples of Comparative Examples 1 and 3 had unevenness in roughness, and the other samples were uniformly roughened. Comparative Examples 2 and 4
It was confirmed that the surface of the insulating layer had polishing scratches, though the surface was uniformly roughened.

Next, with respect to the two-layer printed wiring board manufactured as described above, fine wiring formability, plating peel strength, solder heat resistance, and interlayer insulation resistance (interlayer insulation resistance between the first circuit and the second circuit) And resolution. The results are shown in Tables 1 and 2.

The test method was as follows. Fine wiring formability: 50 μm line width on part of the second circuit
Were formed at intervals of 50 μm, and this portion was observed using a metallographic microscope to check for disconnection. In Tables 1 and 2, ○ means no disconnection and × means disconnection. Plating peel strength (unit: kN / m): forming a portion having a width of 10 mm and a length of 100 mm as a part of the second circuit,
One end of this part was gripped with a gripper, and the load was measured when the piece was peeled off by about 50 mm so that the pulling direction was perpendicular to the second circuit surface. Solder heat resistance (unit: seconds): Three 50 mm square test pieces were floated in a solder bath maintained at 260 ° C., and the time required for blistering was measured. In Tables 1 and 2, for example, ">60" indicates that the test was terminated in 60 seconds because no blister occurred. Interlayer insulation resistance (unit: 10 GΩ): The insulation resistance between the first circuit and the second circuit was measured using a test piece cut out so as not to include an interlayer connection part. Resolution (unit: μm): 10 to 50 μm in diameter
Using a circular black circle with a size changed for each μm as a mask,
The resolution was defined as the smallest diameter of the mask that could form the interlayer insulating hole.

[0044]

[Table 1]

[0045]

[Table 2]

From Tables 1 and 2, it can be seen that in Examples 1 to 6, the inter-layer insulation resistance and fine wiring formability were all better than Comparative Examples 1 to 4, and the plating peel strength and solder heat resistance were mechanically polished. It is shown to be equivalent to Comparative Examples 2 and 3 using baffle polishing.

[0047]

According to the radiation polymerizable insulating resin composition of the present invention, an insulating layer having a high insulation resistance can be formed, and an insulating layer which can be roughened without using mechanical polishing means is formed. Therefore, there is no problem in forming the fine wiring. Further, the multilayer printed wiring board according to the present invention has a high insulation resistance of the insulating layer, and enables high-density wiring.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a change in form according to a process in the order of (a), (b), (c), (d) and (e).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first circuit 2 insulating substrate 3 a radiation-polymerizable insulating resin composition layer 3 insulating layer 4 interlayer connection hole 5 plating layer 6 second circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // C08L 9/02 C08L 9/02 63/00 63/00

Claims (2)

[Claims] 1. A radiation-polymerizable insulating resin composition comprising, as essential components, a compound polymerizable by irradiation with radiation, an epoxy resin, an epoxy-modified acrylonitrile-butadiene rubber, and a phenol resin. 2. A multilayer printed wiring board comprising an interlayer insulating layer formed by using the radiation-polymerizable insulating resin composition according to claim 1.