JP2002252470A - Interlayer insulating material film for printed wiring board and multilayer printed wiring board using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer insulating material film for a printed wiring film and a multilayer printed wiring board wherein both an embedding characteristic of a via hole and/or through hole and the peel strength of a conductive layer are provided. SOLUTION: The interlayer insulating material film for the printed wiring board comprises at least a support base film 3, an insulating resin layer 2 which is, being solid at a normal temperature, laminated on its surface, and a protecting film 1. At laminating, only the support base film is peeled so as to bond to an inner-layer circuit substrate by a resin surface to which the support base film is contacted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board of a build-up type in which conductive circuit layers and insulating layers are alternately stacked, and to cover an inner layer circuit pattern and to fill a surface via hole and / or a through hole with a resin. And a method for manufacturing a multilayer printed wiring board using the same.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a multilayer printed wiring board, a plurality of B-staged prepreg sheets in which glass cloth is impregnated with epoxy resin as an insulating adhesive layer is laminated on an inner circuit board on which a circuit is formed and laminated. There is known a method of pressing and making interlayer conduction by through holes.
However, this method requires large-scale equipment and a long time to perform heating and pressure molding by a lamination press, so that the cost is high, and the thickness of the interlayer is reduced because a glass cloth having a relatively high dielectric constant is used for the prepreg sheet. In addition to the limitations, there were problems such as anxiety about insulation due to CAF.

As a means for solving such a problem, attention has been paid to a build-up type multilayer printed wiring board manufacturing technique in which organic insulating layers are alternately stacked on conductor layers of an inner circuit board. JP-A-7-202426 and JP-A-8-157566 disclose a multi-layer printed circuit by applying an undercoat adhesive to an inner circuit board on which a circuit is formed, temporarily drying the laminate, and bonding a copper foil or a copper foil with an adhesive. A method for making a board is disclosed. Also, JP-A-8-6496
No. 0 discloses a method of manufacturing a multilayer printed wiring board by applying an undercoat adhesive, temporarily drying, bonding a film-like additive adhesive, heating and curing, roughening with an alkaline oxidizing agent, and forming a conductive layer by plating. Are known. However, in these methods, since the undercoat adhesive layer is formed in an ink state, there is a high possibility that dust enters the adhesive layer during the process, and there is a problem that a circuit failure such as disconnection or short circuit occurs.

Further, Japanese Patent Application Laid-Open No. 11-87927 discloses that a resin comprising a high molecular weight epoxy resin, a liquid epoxy resin, and a binder polymer is formed on a supporting base film and laminated on a patterned inner layer circuit board. A method for manufacturing a multilayer printed wiring board is disclosed. However, since the surface of the insulating resin layer formed by the lamination is the surface in contact with the supporting base film, the upper and lower sides of the insulating resin layer are reversed during application. Since the insulating resin on the supporting base film is B-staged, the amount of the remaining solvent is larger on the supporting base film side and smaller on the protective film side, which is an adhesive surface. Since the amount of residual solvent is closely related to the flexibility of the resin, the flexibility of the resin on the adhesive surface with a small amount of residual solvent is reduced,
Embedding of the surface via holes and / or through holes has been a problem.

[0005]

When the flexibility of the resin is low as described above, the embedding of surface via holes and / or through holes during lamination of the insulating film becomes insufficient. Therefore, when the amount of the residual solvent is increased to increase the flexibility of the resin, the amount of the residual solvent on the resin surface on the support base film side on which the roughening and plating treatment is performed in the insulating material film which is peeled off and laminated on the conventional protective film is conventionally performed. And the strength of the resin is insufficient, and the peel strength of the conductor layer is reduced. For this reason, it has been difficult for the conventional laminating method to achieve both the embedding property of the via hole and / or the through hole and the peel strength of the conductor layer.

Therefore, in the present invention, when the insulating material film is laminated, the resin is adhered to the resin surface on the supporting base film side, which has a large amount of residual solvent and is highly flexible, to improve the embedding property of the surface via holes and / or through holes. Simultaneously, the resin surface on the strong protective film side with less residual solvent is roughened and plated to improve the peel strength of the conductor layer, and the interlayer insulating film for printed wiring boards, and the high reliability using this. The purpose is to develop a multilayer printed wiring board.

[0007]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention of claim 1 provides at least a supporting base film and a normal temperature solid insulating resin layer laminated on the surface thereof. And a protective film for a printed wiring board, wherein the supporting base film is provided so as to be peelable during lamination.

According to a second aspect of the present invention, the interlayer insulating material for a printed wiring board according to the first aspect of the present invention is characterized in that the room temperature solid insulating resin layer contains a thermosetting resin, a curing agent, and an inorganic or organic filler. Film.

The invention according to claim 3 is characterized in that the thermosetting resin is a polyfunctional epoxy resin and the curing agent is an epoxy resin curing agent. Film.

The invention according to claim 4 is characterized in that the insulating resin layer at room temperature solid contains at least one kind of thermoplastic resin such as polyether sulfone, phenoxy resin, polyimide and the like. This is an interlayer insulating film for a printed wiring board.

According to a fifth aspect of the present invention, in the interlayer insulating film for a printed wiring board, the protective film and the resin surface on the side where the protective film is bonded are subjected to corona treatment or plasma treatment. 4. The interlayer insulating film for a printed wiring board according to item 1.

According to a sixth aspect of the present invention, there is provided a multilayer printed circuit comprising the interlayer insulating film for a printed wiring board according to any one of the first to fifth aspects, wherein the base film itself is laminated and integrated on an inner circuit board with a peeled surface. It is a wiring board.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An interlayer insulating film for a printed wiring board according to the present invention and a method for manufacturing a multilayer printed wiring board using the same will be described with reference to the drawings. The interlayer insulating material film for a printed wiring board of the present invention is obtained by applying an insulating insulating resin varnish dissolved in a predetermined organic solvent using a base film (3 in the figure) as a support, and then drying the solvent by heating and / or hot air blowing. To form an insulating resin layer (2 in the figure) solid at room temperature. Further, the surface of the insulating resin layer without the support base film is covered with a protective film (1 in the figure) to obtain an interlayer insulating film for a printed wiring board. At this time, the amount of the residual solvent in the insulating resin layer is smaller on the side of the protective film where the film is not in contact with the film at the time of drying, and is larger on the side of the supporting base film.

In the conventional interlayer insulating film for printed wiring boards, the protective film is peeled off (FIG. 1A), laminated on both sides of the inner circuit board (4 in FIG. 1) (FIG. 1B), and the supporting base is removed. The film is peeled to form an insulating resin layer. Then, through holes and / or via holes are formed at predetermined positions using a drill and / or a CO ₂ laser in order to obtain conduction of the upper and lower layer circuits. If necessary, the surface of the insulating resin layer is roughened by a dry and / or wet method, and then the conductor layer is formed by dry and / or wet plating. By repeating the above steps a plurality of times, a multilayer printed wiring board is manufactured. In the conventional manufacturing method,
Since the amount of residual solvent is small and the resin surface on the supporting base film side with low flexibility is bonded, the coating of the inner layer circuit board or the embedding of through holes and / or via holes is poor. Since the conductor layer is formed on the resin on the side of the weak protective film, the problem is that the peel strength is low.

In the interlayer insulating film for a printed wiring board according to the present invention, the supporting base film is peeled off (FIG. 2).
A) After laminating on both sides of the inner circuit board (FIG. 2B), the protective film is peeled off to form an insulating resin layer.
Thereafter, a multilayer printed wiring board can be obtained by the same method as in the related art. According to the present invention, by laminating with the resin on the support base film side having high flexibility, the covering property of the inner layer circuit board or the embedding property of the through holes and / or via holes is improved, and the conductor is formed on the resin on the stronger protective film side. Since the layer is formed, the peel strength is also improved.

The room-temperature solid insulating resin layer in the present invention is a resin mainly composed of a thermosetting resin, softened by heating and capable of forming a film. There is no particular limitation as long as the properties required for the interlayer insulating material are satisfied. For example, epoxy resin-based, acrylic resin-based, polyimide resin-based, polyamideimide resin-based, polycyanate resin-based, polyester resin-based, thermosetting polyphenylene ether resin-based, and the like, and these may be used in combination of two or more. Alternatively, an insulating film having a multilayer structure may be used. When the interlayer insulating film for a printed wiring board according to the present invention is applied as a multilayer printed wiring board, it is preferable to use an epoxy resin from the viewpoints of mechanical, electrical, chemical properties, and cost. Resins are preferred.

Examples of the polyfunctional epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, alkylphenol novolak epoxy resin, biphenol epoxy resin, and naphthalene epoxy resin. , Dicyclopentadiene type epoxy resins, epoxidized condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group, triglycidyl isocyanurate, alicyclic epoxy resins, and the like, or any combination of two or more of them. Can be used. Further, the above-mentioned epoxy resin brominated for imparting flame retardancy is used.

The curing agent used in the present invention is not particularly limited, but a curing agent corresponding thereto can be selected by selecting a thermosetting resin. For example, when an epoxy resin is used as the thermosetting resin, an epoxy resin curing agent can be used. The epoxy resin curing agent includes a catalyst type and a polyaddition type, and both known types can be used. For example, polyaddition type epoxy resin curing agents include polyphenols such as phenol novolak, amine curing agents such as dicyandiamide, diaminodiphenylmethane, diaminodiphenylsulfone, pyromellitic anhydride, trimellitic anhydride, and benzophenonetetracarboxylic acid. And the like, or a mixture thereof. Among them, polyhydric phenols such as phenol novolak are preferably used from the viewpoint of low water absorption and high heat resistance. The compounding ratio of these curing agents differs depending on the selection of the curing agent and the thermosetting resin to be used, and is usually determined so that the glass transition temperature of the cured product becomes high.
For example, when using phenol novolak, it is preferable to mix the epoxy equivalent and the hydroxyl equivalent at about 1: 1.

In the present invention, a known inorganic or organic filler can be added to the room temperature solid insulating resin layer for the purpose of improving mechanical, thermal or electrical properties. In addition, the compounding ratio varies depending on the selection of the thermosetting resin,
When added, 5 to 40 wt.
% Is preferable. As the organic filler, epoxy resin powder, melamine resin powder, urea resin powder, guanamine resin powder, polyester resin powder, etc.
Examples of the inorganic filler include silica, alumina, and titanium oxide. Silica fillers are often used because they have a low dielectric constant, a low coefficient of linear expansion, and are easily separated from the insulating resin by alkali treatment.

The purpose of adding the thermoplastic resin used in the present invention is particularly to improve the toughness of the resin.
Usually, an epoxy resin is excellent in plating adhesion to copper and heat resistance, but has a hard and brittle property, and may cause a defect such as a resin crack in a thermal shock test. In the present invention, by adding a thermoplastic resin, a more excellent interlayer insulating film for a printed wiring board can be obtained.
It is desirable that such a thermoplastic resin has heat resistance and can be dissolved and mixed in the same solvent as the above-mentioned thermosetting resin and curing agent.

As such a thermoplastic resin, for example, a phenoxy resin, polyimide, or polyether sulfone can be used. Usually, when these thermoplastic resins are added, the mixing ratio is 5 to 50 wt.
%. The reason for this is that if it is less than 5 wt%, the effect of increasing toughness by addition is poor, and 50 wt%
Above, the properties of the epoxy resin of the thermosetting resin cannot be utilized, and the plating properties may be inferior, and further, problems such as a decrease in heat resistance in a high temperature region of 200 ° C. or more may occur.

A known curing catalyst can be added to the insulating resin used in the present invention for the purpose of accelerating the curing reaction. For example, when an epoxy resin is used as a thermosetting resin and a polyaddition type epoxy resin curing agent is used as a curing agent, triphenylphosphine, tri-4-methylphenylphosphine, tri-4-methoxyphenylphosphine, tributylphosphine is used. , Organic phosphine compounds such as trioctylphosphine and tri-2-cyanoethylphosphine, and tetraphenylborate salts thereof;
Tertiary amines such as tributylamine, triethylamine and triamylamine; quaternary ammonium salts such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide and triethylammonium tetraphenylborate; 2-ethylimidazole and 2-ethyl-4-
Examples include, but are not limited to, imidazoles such as methyl imidazole. Of these, the use of organic phosphine compounds and imidazoles is particularly preferred for achieving the object of the present invention. The mixing ratio of these curing catalysts can be added at an arbitrary ratio so as to obtain a desired gel time. Usually, the gel time of the composition is 80 ° C.
It is preferable to mix them at each predetermined temperature of up to 250 ° C. for 1 to 15 minutes.

Examples of the organic solvent used in the present invention include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ethyl acetate, butyl acetate; Cellosolves such as butyl cellosolve,
In addition to carbitols such as carbitol and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like can be used alone or in combination of two or more.

The support base film used in the present invention includes polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET), polycarbonate, release paper and copper foil,
Examples include metal foils such as aluminum foil. Among them, it is particularly preferable to use a polyester film in terms of price, heat resistance, dimensional stability and the like. The thickness of the supporting base film is generally from 10 to 150 μm. In the present invention, it is effective to subject the support base film to a release treatment in order to exhibit the features described in claim 1.

As the protective film used in the present invention, the same as the supporting base film, polyolefins such as polyethylene, polyvinyl chloride and polypropylene, PET
And the like, and further, release paper and the like. The thickness of the protective film is generally from 10 to 100 μm. In the present invention, it is particularly preferable that the resin surface in contact with the protective film is previously subjected to corona treatment or plasma treatment as described in claim 5. This is because the adhesion of the conductor layer formed by plating on the resin is improved, and the peel strength of the conductor layer is increased.

The inner circuit board used in the present invention includes:
For example, plastic substrates, ceramic substrates, metal substrates,
A film substrate can be used. Specific examples include a glass epoxy substrate, a bismaleimide triazine substrate, an aramid fiber nonwoven substrate, a liquid crystal polymer substrate, an aluminum substrate, an iron substrate, a polyimide substrate, and the like. Substrate can be used.

The method for laminating an interlayer insulating film for a printed wiring board according to the present invention will be described. As the laminating, a pressurizing type, a depressurizing type, and a type using a combination thereof can also be used. A batch type or a continuous type using a roll may be used, and it is more preferable to simultaneously laminate both surfaces from the viewpoint of workability. The lamination conditions are as follows: the hot melt viscosity of the room temperature solid insulating resin layer of the present invention, the thickness and the through-hole diameter, depth and / or surface via-hole diameter of the inner circuit board,
Although it depends on the depth, in general, the pressing temperature is 70 to 20.
0 ° C., a pressure of 1 to 10 kgf / cm ² ,
Laminate under reduced pressure of 0 mmHg or less. When the through hole diameter is large and deep, that is, when the plate thickness is large, the insulating resin layer is thick, and lamination conditions at high temperature and / or high pressure are required. Generally, a resin thickness of about 1.4 mm and a through-hole diameter of about 1 mm can be favorably filled with resin.

Through holes and / or via holes are formed in the insulating resin layer formed by lamination in order to obtain electrical continuity between upper and lower circuits. The formation of the through hole and / or the via hole is performed by drilling a predetermined position with a laser and / or a drill. Thereafter, if necessary, the surface of the insulating resin layer is roughened by a dry method and / or a wet method. Next, the conductor layer is formed by dry and / or wet plating to manufacture a multilayer printed wiring board. Examples of the dry roughening method for the insulating resin layer surface include mechanical polishing such as buffing and sandblasting, and plasma etching. On the other hand, permanganate,
Chemical treatment such as dichromate, ozone, oxidizing agents such as hydrogen peroxide / sulfuric acid, nitric acid and the like can be mentioned. After forming an irregular anchor on the surface of the insulating resin layer as required, a conductor layer is formed by dry plating such as evaporation, sputtering, or ion plating and / or wet plating such as electroless or electrolytic plating.

[0029]

EXAMPLES Examples and comparative examples for producing an interlayer insulating film for a printed wiring board and a multilayer printed wiring board according to the present invention will be described below.

Example 1 (a) 100 parts by weight of EPPN-502H (Nippon Kayaku) as an epoxy resin component, 62.7 parts by weight of phenol novolak (Nippon Kayaku) as a curing agent for epoxy resin, heat 65.1 parts by weight of phenotote YP-50 (manufactured by Toto Kasei Co., Ltd.) as cycloplastic and DM
F was dissolved in a mixed solvent. 45.6 parts by weight of Admafine SO-C1 (manufactured by Admatechs) as a silica filler and 2-ethyl-4- as a curing catalyst were added to this solution.
0.22 parts by weight of methyl imidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was kneaded and dispersed by a roll, followed by stirring and defoaming.
A varnish of insulating resin for printed wiring boards was prepared. The varnish was applied on a PET support base film having a thickness of 30 μm using a roll coater so that the thickness after drying was 50 μm, and dried at 80 ° C. for 10 minutes. Further, after a resin surface having no supporting base film was subjected to corona treatment, a PET protective film which had been subjected to corona treatment in advance was attached to obtain an interlayer insulating film for a printed wiring board.

(B) The support base film of the insulating film thus obtained was peeled off, and both sides were simultaneously laminated on a glass epoxy inner layer circuit board by a vacuum laminator. The laminating conditions are as follows:
° C, pressure 4 kgf / cm ² , pressure 30 cm / min, pressure 2
The test was performed at 0 mmHg or less. After cooling to around room temperature,
The protective film was peeled off. The resin is cured by heating at 180 ° C. for 2 hours, and C is added to a predetermined φ0.10 mm via hole.
Drilling was performed with an O ₂ laser. Then, the surface of the insulating resin layer was roughened with an alkaline oxidizing agent of permanganate to form a conductor layer over the entire surface by electroless and / or electrolytic plating, and then a circuit pattern was formed according to a subtractive method. By repeating the above step (b) twice, a two-layer build-up printed wiring board was obtained.

Example 2 (a) As an epoxy resin, 80 parts by weight of EPPN-502H (manufactured by Nippon Kayaku), 20 parts by weight of Epicoat 828EL (manufactured by Yuka Shell Epoxy), and phenol novolak (manufactured by Nippon Kayaku) 62.7 parts by weight, and 65.1 parts by weight of phenotote YP-50 (produced by Toto Kasei Co., Ltd.) as a thermoplastic resin were dissolved in a mixed solvent of cyclohexanone and DMF. To this solution, Tospearl 105 as a resin filler was added.
22.8 parts by weight (manufactured by Toshiba Silicone Co., Ltd.) and 0.22 parts by weight of a curing catalyst, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.), were dispersed by a kneading roll, and then stirred and defoamed. Then, a varnish of an insulating resin for a printed wiring board was prepared. The varnish was applied on a 30 μm-thick PET support base film using a roll coater so that the thickness after drying became 50 μm, and dried at 80 to 100 ° C. for 10 minutes. Further, after a resin surface having no supporting base film was subjected to corona treatment, a PET protective film which had been subjected to corona treatment in advance was attached to obtain an interlayer insulating film for a printed wiring board.

(B) Lamination and formation of a conductor layer were performed in the same manner as in (b) of Example 1. The laminating conditions were as follows: using a continuous method, the temperature was 90 ° C., the pressure was 3 kgf / cm ² , the speed was 30 cm / min, and the pressure was 20 mmHg or less.

Example 3 (a) 100 parts by weight of VG3101M80 (manufactured by Mitsui Chemicals, Inc.) as an epoxy resin component, 68.3 parts by weight of Kayahard NHN (manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin curing agent, and thermoplastic resin 67.3 parts by weight of SUMIKAEXCEL 5003P (manufactured by Sumitomo Chemical Co., Ltd.) was dissolved in the MEK solution. Admafine S, a silica filler, is added to this solution.
47.1 parts by weight of O-C1 (manufactured by Admatechs) and 0.24 parts by weight of a curing catalyst, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.), were dispersed by a kneading roll, and then stirred and dispersed. Defoaming was performed to prepare a varnish of an insulating resin for a printed wiring board. This varnish is coated with a 30 μm thick PE
It was applied on a T support base film by a roll coater so that the thickness after drying became 50 μm, and dried at 80 to 100 ° C. for 10 minutes. Further, after the resin surface having no supporting base film was subjected to oxygen plasma treatment, a PET protective film which had been subjected to oxygen plasma treatment in advance was bonded to obtain an interlayer insulating film for a printed wiring board.

(B) Lamination and formation of a conductor layer were performed in the same manner as in (b) of Example 1. Laminating conditions were performed using a continuous method at a temperature of 100 ° C., a pressure of 4 kgf / cm ² , a speed of 30 cm / min, and a pressure of 10 mmHg or less.

Example 4 (a) 100 parts by weight of VG3101M80 (manufactured by Mitsui Chemicals, Inc.) as an epoxy resin component, 68.3 parts by weight of Kayahard NHN (manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin curing agent, and thermoplastic resin 67.3 parts by weight of SUMIKAEXCEL 5003P (manufactured by Sumitomo Chemical Co., Ltd.) was dissolved in the MEK solution. To this solution, Tospearl 105 as a resin filler was added.
23.6 parts by weight (manufactured by Toshiba Silicone Co., Ltd.) and 0.24 part by weight of 2-ethyl-4-methylimidazole (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a curing catalyst were dispersed by a kneading roll, followed by stirring and defoaming. Then, a varnish of an insulating resin for a printed wiring board was prepared. The varnish was applied on a 30 μm-thick PET support base film using a roll coater so that the thickness after drying became 50 μm, and dried at 80 to 100 ° C. for 10 minutes. Furthermore, after the resin surface without the supporting base film was subjected to oxygen plasma treatment, a PET protective film previously subjected to oxygen plasma treatment was bonded to obtain an interlayer insulating film for a printed wiring board.

(B) Lamination and formation of a conductor layer were performed in the same manner as in (b) of Example 1. The laminating conditions were a continuous method using a temperature of 100 ° C., a pressure of 3 kgf / cm ² , a speed of 30 cm / min, and a pressure of 20 mmHg or less.

Comparative Example 1 (a) 100 parts by weight of EPPN-502H (Nippon Kayaku) as an epoxy resin component, 62.7 parts by weight of phenol novolak (Nippon Kayaku) as an epoxy resin curing agent, heat As a plastic resin, 65.1 parts by weight of phenotote YP-50 (manufactured by Toto Kasei Co., Ltd.) was added with cyclohexanone and DM.
F was dissolved in a mixed solvent. 45.6 parts by weight of Admafine SO-C1 (manufactured by Admatechs) as a silica filler and 2-ethyl-4- as a curing catalyst were added to this solution.
0.22 parts by weight of methyl imidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was kneaded and dispersed by a roll, followed by stirring and defoaming.
A varnish of insulating resin for printed wiring boards was prepared. The varnish was applied on a PET support base film having a thickness of 30 μm using a roll coater so that the thickness after drying became 50 μm, and dried at 80 ° C. for 10 minutes. Further, a PET protective film was bonded to the resin surface having no supporting base film to obtain an interlayer insulating film for a printed wiring board.

(B) The protective film of the insulating film thus obtained was peeled off, and both surfaces were simultaneously laminated on a glass epoxy inner layer circuit board with a vacuum laminator. Laminating conditions were the same as those in Example 1 (b). After allowing to cool to around room temperature, the supporting base film was peeled off. Heat at 180 ° C for 2 hours to cure the resin,
A predetermined φ0.10 mm via hole was punched with a CO ₂ laser. Then, the surface of the insulating resin layer is roughened with an alkaline oxidizing agent of permanganate to form a conductor layer by electroless and / or electrolytic plating over the entire surface.
A circuit pattern was formed according to a subtractive method. By repeating the above steps twice, a build-up two-layer printed wiring board was obtained.

Comparative Example 2 (a) As an epoxy resin, 80 parts by weight of EPPN-502H (manufactured by Nippon Kayaku), 20 parts by weight of Epicoat 828EL (manufactured by Yuka Shell Epoxy), and phenol novolak (manufactured by Nippon Kayaku) 62.7 parts by weight, and 65.1 parts by weight of phenotote YP-50 (produced by Toto Kasei Co., Ltd.) as a thermoplastic resin were dissolved in a mixed solvent of cyclohexanone and DMF. To this solution, Tospearl 105 as a resin filler was added.
22.8 parts by weight (manufactured by Toshiba Silicone Co., Ltd.) and 0.22 parts by weight of a curing catalyst, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.), were dispersed by a kneading roll, and then stirred and defoamed. Then, a varnish of an insulating resin for a printed wiring board was prepared. The varnish was applied on a 30 μm-thick PET support base film using a roll coater so that the thickness after drying became 50 μm, and dried at 80 to 100 ° C. for 10 minutes. Further, a PET protective film was bonded to the resin surface having no supporting base film to obtain an interlayer insulating film for a printed wiring board.

(B) The protective film of the insulating film thus obtained was peeled off, and both surfaces were simultaneously laminated on a glass epoxy inner layer circuit board with a vacuum laminator. Lamination was performed under the same conditions as in Example 2 (b). After allowing to cool to around room temperature, the supporting base film was peeled off. Heat at 180 ° C for 2 hours to cure the resin,
A predetermined φ0.10 mm via hole was punched with a CO ₂ laser. Then, the surface of the insulating resin layer is roughened with an alkaline oxidizing agent of permanganate to form a conductor layer by electroless and / or electrolytic plating over the entire surface.
A circuit pattern was formed according to a subtractive method. By repeating the above steps twice, a build-up two-layer printed wiring board was obtained.

The results of evaluating the adhesion strength of the copper plating film of the printed wiring board manufactured as described above, the filling property of the via hole during lamination, and the reliability of interlayer insulation are shown in the table. The adhesion strength of the copper plating film is JIS-C6481
And a 90-degree peel test of a 1 cm wide pattern. Regarding the filling property of the via hole, the resin shape of the cross section was observed, and the state in which the inside of the hole was completely filled with the resin was defined as “good”, and the other state was defined as “bad”. Interlayer insulation reliability evaluation was performed by feeding a test piece prepared based on the JIS-C5012 standard to an advanced accelerated life tester manufactured by Tabai Espec Co., Ltd. under the conditions of 121 ° C./85% and 5 V ·
The voltage was applied for 100 hours and subsequently at 20 V for 100 hours, and the insulation resistance was measured over time. The measurement and analysis of the insulation resistance were performed by Kusumoto Kasei's insulation deterioration characteristic evaluation system SIR11. The migration was performed when the resistance value was 10 ⁶ Ω or less. The case was regarded as "poor".

[0043]

[Table 1]

[0044]

According to the present invention, according to the present invention, the lamination of an interlayer insulating film for a printed wiring board is more flexible.
By bonding on the supporting base film side, it is possible to provide a multilayer printed wiring board which exhibits excellent via hole filling properties and excellent insulation reliability. Also, by roughening and plating the insulating resin layer on the strong protective film side,
The peel strength of the copper plating film is also improved.

[0045]

[Brief description of the drawings]

FIG. 1 shows a method of laminating a conventional interlayer insulating film for a printed wiring board to an inner circuit board. First, in (a), the protective film of the insulating film is peeled off,
In (b), both sides are simultaneously laminated on the inner circuit board.

FIG. 2 shows a method of laminating an insulating film for a printed wiring board on an inner circuit board according to the present invention.
First, the supporting base film of the insulating film is peeled off in (a), and both surfaces are simultaneously laminated on the inner circuit board in (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective film 2 Room temperature solid insulating resin layer 3 Support base film 4 Inner circuit board

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 71/12 C08L 71/12 79/08 79/08 B 81/06 81/06 F term (reference) 4F073 AA01 BA22 BA24 BB01 CA01 CA21 4J002 AA021 CC042 CC164 CC184 CC194 CD004 CD021 CD041 CD051 CD061 CD071 CD141 CF004 CH083 CM043 CN033 DE137 DE147 DJ017 EL136 EN028 EN076 EN138 ET006 EU118 EW148 EY018 FA014 FD014 FD017 FD142 AFD12 A12 CC04 DD12A12 DD04 A12 CC EE14 EE18 FF04 FF13 FF14 FF15 GG15 GG17 GG27 GG28 HH11 HH40

Claims (6)

[Claims] 1. An interlayer insulating film for a printed wiring board, comprising at least a supporting base film and a room temperature solid insulating resin layer and a protective film laminated on the surface thereof,
An interlayer insulating film for a printed wiring board, wherein a supporting base film is provided so as to be peelable during lamination. 2. The interlayer insulating film for a printed wiring board according to claim 1, wherein the normal temperature solid insulating resin layer contains a thermosetting resin, a curing agent, and an inorganic or organic filler. 3. The thermosetting resin is a polyfunctional epoxy resin,
3. The interlayer insulating film for a printed wiring board according to claim 1, wherein the curing agent is an epoxy resin curing agent. 4. The method according to claim 1, wherein the insulating resin layer which is solid at room temperature contains at least one kind of thermoplastic resin such as polyether sulfone, phenoxy resin and polyimide.
4. The interlayer insulating film for a printed wiring board according to any one of items 1 to 3. 5. The printed wiring according to claim 1, wherein the protective film and the resin surface on the side where the protective film is bonded are subjected to corona treatment or plasma treatment in the interlayer insulating film for a printed wiring board. Interlayer insulating film for board. 6. A multilayer printed wiring board, wherein the base film itself of the interlayer insulating film for a printed wiring board according to claim 1 is laminated and integrated with an inner circuit board.