JPH07170073A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To manufacture a multilayer wiring board provided with a blind viahole by a hot roller by a method wherein an alkali soluble-resin layer is formed on an inner panel layer having a conductor circuit pattern, an alkali soluble-resin layer formed on the roughened surface of a copper foil is laminated thereon, a fine hole is bored in the copper foil, and the conductor pattern is exposed to be connected to the copper foil. CONSTITUTION:A second alkali-soluble resin layer 3 is formed on an inner layer panel 7 having a conductor circuit pattern 6. On the other hand, a first alkali-soluble resin layer 2 is formed on the roughened surface of a copper foil 1, which is formed on the second resin layer 3. Then, fine holes are bored in the copper foil 1 at prescribed spots by etching. The resin layer exposed in the holes are dissolved into an alkaline solution to make the conductor circuit pattern 6 of the inner layer panel 7 exposed, the resin layers 2 and 3 are hardened, and the conductor circuit pattern 6 of the inner layer panel 7 is electrically connected to the surface of the copper foil 1 with conductive material. Thus a multilayer printed wiring board having a blind viahole excellent in physical, electrical characteristics, and productivity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board suitable for high-density mounting, and more specifically to mass production of a multilayer printed wiring board having a blind via hole excellent in physical characteristics and electrical characteristics. A manufacturing method having excellent properties is provided.

[0002]

2. Description of the Related Art As electronic equipment becomes smaller and more multifunctional,
At present, printed wiring boards are moving toward higher density. For example, thinning conductor circuits, increasing the number of layers, reducing the diameter of via holes, including through via holes, interstitial via holes such as blind via holes or balled via holes, and improving the surface mounting of small chip components. Examples include density mounting.

In order to explain a conventional method for manufacturing a multilayer printed wiring board having a blind via hole, schematic cross sections of respective steps are shown in FIGS. 11 to 18. As shown in FIG. 11, an inner layer panel 7 on which a conductor circuit pattern 6 has been previously formed by an etching method is prepared, and one or two prepregs 14 are superposed between the outer layer copper foil 1 and the inner layer panel 7. The copper clad laminate panel having the inner layer conductor circuit pattern shown in FIG. 12 is obtained by laying up and hot pressing at a temperature of 160 to 180 ° C. for 60 to 120 minutes at a pressing pressure of 15 to 50 kg / cm ² . A vacuum hot press may be used when accuracy is required.

Next, holes are sequentially formed at predetermined positions by a drill machine to form blind via hole 15 as shown in FIG. When the through hole 10 is continuously provided, the result is as shown in FIG.

Hereinafter, conventional electroless copper plating and electrolytic copper plating will be performed to form the plated through holes 11 as shown in FIG.
After the etching resist 12 is formed (FIG. 16) and the etching is subsequently performed, the result is as shown in FIG. 17. Finally, the etching resist film is stripped, and a multilayer printed wiring board having a blind via hole is formed. Obtained (FIG. 18).

In order to form a blind via hole with a drill in this way, it is not possible to stack a plurality of panels like a normal through hole, and it is necessary to drill one hole at a time, which requires a very long time for drilling. However, there is a drawback that the production efficiency is poor. Further, in drilling, in order to control the depth of the tip of the drill, it is necessary to match the moving distance in the drilling direction, generally the Z-axis direction, with the depth of the conductor circuit pattern on the inner layer panel surface. However, a drill with a small diameter of about 0.1 to 0.5 mm has a large runout, and there are variations in the position of the conductor circuit pattern in the Z-axis direction. The conductor circuit pattern did not reach, and it was not connected in the plating in the subsequent process, causing a blind via hole defect. Conversely, if the drilling process was too deep, it contacted the conductor circuit pattern below it, resulting in a short circuit defect. .

In the conventional method for manufacturing a multilayer printed wiring board, a hot press or a vacuum hot press is generally used as described above. Therefore, as a preparation for the hot press, an inner layer panel, a prepreg, a copper foil, It is necessary to lay up a release film and a mirror press plate, thermocompress them with a hot press or a vacuum heat press, and then take them out and dismantle them. This manufacturing method is usually batch production, and the number of steps is large and complicated. There is a problem in that an expensive device is required to automate the batch operation to increase productivity, and a large-sized heat press device capable of thermocompression bonding in a large amount is required.

In order to solve the above problems of the conventional method for producing a multilayer printed wiring board, the present inventors have already applied copper-clad insulation to a copper foil coated with an alkali-soluble resin composition having fluidity when heated. A method for manufacturing a multilayer printed wiring board having a blind via hole using a sheet is proposed (Japanese Patent Application No. 4-56348, Japanese Patent Application No. 4-88395).
Japanese Patent Application No. 4-112304 and Japanese Patent Application No. 4-237.
733). 19 to 27 show schematic cross-sectional views of each step.

As shown in FIG. 19, a copper foil 1 is coated with a first resin composition containing an organic solvent which is soluble in alkali and has low heat fluidity, and is dried to form a layer 2 of the first resin composition.
A second resin composition containing an organic solvent that is soluble in alkali and has high heat fluidity is applied onto the above and dried to prepare a copper-clad insulating sheet 16. The resin side of the copper-clad insulating sheet is laminated on the inner layer panel 7 provided with the conductor circuit pattern 6 in advance with a heat roll (FIG. 20), and the etching resist 1 is removed except at a predetermined position where a blind via hole is formed.
2 is formed and unnecessary copper foil is etched to form fine holes 8 of the copper foil (FIG. 21).

Next, the exposed layer of the resin composition and the resist are dissolved in an alkaline solution to form a blind via hole 9 (FIG. 22). After curing the resin composition layer, if necessary, through holes are drilled at predetermined positions (Fig. 23), electroless copper plating and electrolytic copper plating are performed, and conductive layers are provided on the blind via holes and through holes. Then, by electrically connecting the conductor layers and selectively etching the copper foil on the surface to form a conductor pattern, a multilayer printed wiring board having blind via holes is obtained (FIGS. 24 to 27).

However, the drying conditions for producing the copper-clad insulating sheet take about 15 minutes at 70 ° C. if the thickness of the first resin composition is, for example, 40 μm (after drying), and the second resin is used. Since the composition is applied on the layer of the first resin composition, the solvent of the second resin composition permeates the first resin composition.
It took more time to swell the resin composition layer, and if the thickness was, for example, 30 μm (after drying), it took about 40 minutes at 70 ° C., and the coating productivity was extremely low.

Further, when the first resin composition layer and the second resin composition layer are stacked to increase the total thickness, it becomes difficult to completely remove the solvent from the layers even by drying. . If a small amount of solvent remains in the copper-clad insulating sheet, the subsequent step of curing the layer of the resin composition, for example, preheating at 100 ° C. for 30 minutes and curing at 150 ° C. for 30 minutes causes the solvent to volatilize and generate bubbles. However, there is a drawback that the withstand voltage resistance and solder heat resistance of the obtained insulating layer are deteriorated. In order to solve this, the present inventors have added a crosslinking agent sensitive to an electron beam to the resin composition and semi-cure the layer of the resin composition with the electron beam transmitted through the copper foil to improve the fluidity. It has been found that the generation of bubbles can be prevented by eliminating the heat and completely curing it by applying heat. However, this method has a drawback in that it requires a large-scale and expensive electron beam irradiation device, and the cost of the multilayer printed wiring board using the copper clad insulating sheet increases.

[0013]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the conventional method, produces a multilayer printed wiring board having a blind via hole which is excellent in physical and electrical characteristics, stable in quality, and excellent in mass productivity. It provides a method.

[0014]

According to the method for producing a multilayer printed wiring board of the present invention, an alkali-soluble second resin composition is applied to an inner layer panel having a conductor circuit pattern on one side or both sides, and the conductor is used. Second gap between circuit patterns
The step of filling with the resin composition and drying it; the resin side of the copper-clad insulating sheet obtained by applying the alkali-soluble first resin composition to the roughened surface of the copper foil and drying the second resin, A step of laminating on the layer of the composition; a step of forming a minute hole by etching in a predetermined position of the copper foil; a layer for the resin composition, in which the hole portion is exposed, is dissolved in an alkaline solution to form an inner layer panel. The step of exposing the conductor circuit pattern of (1); the step of curing the layers of the first and second resin compositions; and the step of electrically connecting the conductor circuit pattern of the inner layer panel and the copper foil on the surface with a conductive substance.

In contrast to the conventional case where a first resin composition and a second resin composition are overlaid and coated and dried to prepare a copper clad insulating sheet, the method of the present invention is a layer of the first resin composition. Since the step of coating and drying the copper foil on the copper foil and the step of directly coating and drying the second resin composition on the inner layer panel are different from each other, the first resin composition layer Since the solvent of the second resin composition does not penetrate into and swell, the total drying time can be shortened. Here, it is preferable to use roll laminating as a laminating means because continuous laminating can be performed and productivity is remarkably improved.

In another method for producing a multilayer printed wiring board of the present invention, the resin side of an insulating sheet obtained by applying a second resin composition which is soluble in alkali and has high heat fluidity onto a release film and then drying it is applied. A step of heating and laminating on an inner layer panel having a conductor circuit pattern on one side or both sides and filling a gap between the conductor circuit patterns with a second resin composition; a step of peeling a release film; a rough surface of copper foil Laminating the resin side of the copper-clad insulating sheet obtained by applying the alkali-soluble first resin composition on the activated surface and drying it, on the layer of the second resin composition; A step of etching a micro hole at a position; a step of dissolving the layer of the resin composition exposed at the hole portion with an alkaline solution to expose the conductor circuit pattern of the inner layer panel; first and second resin compositions Cure the layers of Extent; consisting of copper foil conductive circuit pattern and the surface of the inner panel from the step of conducting a conductive material.

In contrast to the case where a conventional copper-clad insulating sheet is prepared by coating and drying the first and second resin compositions, the method of the present invention is characterized in that the first resin composition is applied onto the copper foil. Since the step of coating and drying and the step of coating and drying the second resin composition on the release film are different from each other, the second
Since the solvent of the resin composition does not permeate to swell the layer of the first resin composition, the total drying time can be shortened. In addition, since the insulating sheet is heated and laminated while being pressed by the release film, the layer of the second resin composition flows between the conductor patterns of the inner layer panel, and the surface on the release film side can be made smooth. Therefore, even if a layer of the first resin composition is laminated in the next step, the smoothness of the surface of the copper foil is maintained. Here, it is preferable to use the roll laminating method as each laminating means, since it can be continuously performed and the productivity is remarkably improved. Further, if a metal roll is used as the roll laminate, the smoothness is further improved.

Another method for producing a multilayer printed wiring board according to the present invention is a method in which a roughened surface of a copper foil is coated with a first alkali-soluble resin composition having a small heating fluidity and is dried. Of the first resin composition of the tension insulating sheet, and the second sheet of the insulating sheet obtained by applying the second resin composition of alkali-soluble and having high heat fluidity onto the release film and drying.
Laminating the layers of the resin composition to produce a copper clad insulating sheet having the layers of the first and second resin compositions; the first and the second layers for the inner layer panel having conductor circuit patterns on one or both sides. The step of heating and laminating the resin side of the copper-clad insulating sheet having the layer of the second resin composition and filling the gap between the conductor circuit patterns with the second resin composition; etching the copper foil at predetermined positions by etching. A step of making a hole; a step of dissolving the resin composition layer exposed at the hole portion with an alkaline solution to expose the conductor circuit pattern of the inner layer panel; curing the first and second resin composition layers Steps: a step of electrically connecting the conductor circuit pattern of the inner layer panel and the copper foil on the surface with a conductive material.

The copper clad insulating sheet used in this method is provided with layers of the first and second resin compositions.
Since the resin composition and the second resin composition are separately applied, the total drying time can be shortened. Here, it is preferable to use the roll laminating method as the laminating means, because it can be continuously performed and the productivity is remarkably improved.

The first and second resin compositions used in the present invention are base resins (hereinafter
It is simply referred to as "base resin". 2) as a main component, and preferably, an adhesive reinforcing agent (crosslinking agent) and a curing agent are mixed therein. It is also preferable to add an active energy ray curing reaction initiator and an active energy ray curing reaction accelerator in order to impart photocurability. Further, if desired, a coloring pigment, a moisture resistant pigment, a defoaming agent, a leveling agent, a thixotropic agent, a polymerization inhibitor or an anti-settling agent may be appropriately added. In addition, an organic solvent is appropriately added to the resin composition in order to have coatability.

As the base resin, a carboxyl group,
A resin containing an alkali-soluble group such as a phenolic hydroxyl group, but having no photosensitivity, or an alkali-soluble group such as a carboxyl group or a phenolic hydroxyl group, and an acryloyl group or a methacryloyl group (hereinafter referred to as “(meth) acryloyl group”). ), Etc., and a photosensitive resin containing a photopolymerizable or photodimerizable photosensitive group can be used. Here, the photosensitivity or photocurability means the property of being cured by electromagnetic waves of short wavelength such as ultraviolet rays.

Examples of the resin which is soluble in alkali but has no photosensitivity include acrylic acid and / or methacrylic acid (hereinafter referred to as "(meth) acrylic acid"), (meth) acrylic acid ester and styrene. Copolymer of other vinyl monomer, half ester obtained by adding alcohol to copolymer of styrene and maleic anhydride, copolymer of styrene and p-hydroxyphenylmaleimide, polyvinylphenol or its copolymer, methyl methacrylate Copolymers, hydroxyethyl methacrylate copolymers, styrene copolymers, phenylmaleimide copolymers, etc., novolac type phenolic resins or novolac type cresol resins, alcohol-containing hydroxyl group-containing polymers and acid anhydride ring-opening adducts, etc. To be

Among the above, the copolymer (hereinafter referred to as "acrylic copolymer") has excellent alkali solubility, and the interlayer insulation resistance and heat resistance when cured to form an insulating layer. Is preferable and is preferable.

The base resin is preferably a photosensitive resin, and the concentration of the photosensitive group is 0.1 to 10.
The range of 0 meq / g is preferable, and 0.3 is more preferable.
To 8.0 meq / g, particularly preferably 0.5 to 5.0 m
eq / g. If the concentration of the photosensitive group is too low, the photosensitivity deteriorates, and if it is too high, the storage stability deteriorates.

As the alkali-soluble and photosensitive resin, for example, epoxy acrylate and / or
Alternatively, a ring-opening adduct of methacrylate (hereinafter, "acrylate and / or methacrylate" is referred to as "(meth) acrylate") and an acid anhydride, a half obtained by adding an unsaturated alcohol to a copolymer of styrene and maleic anhydride. Ester, acrylic copolymer, half ester obtained by adding alcohol to copolymer of styrene and maleic anhydride, copolymer of styrene and p-hydroxyphenylmaleimide, polyvinylphenol or its copolymer, novolak type phenol A compound having a glycidyl group such as glycidyl (meth) acrylate and a C = C unsaturated double bond is added to a resin, a novolac type cresol resin or a polymer such as an alcoholic hydroxyl group-containing polymer and a ring-opening adduct of an acid anhydride. Polymers, styrene and p-hydroxypheny A copolymer of maleimide,
Some of the hydroxyl groups in the phenolic hydroxyl group-containing polymer such as polyvinylphenol or its copolymer, novolac type phenolic resin or novolac type cresol resin have a photosensitive group-containing acid chloride such as (meth) acrylic acid chloride or cinnamic acid chloride. Condensed with and
Alcoholic properties obtained by condensing a part of the hydroxyl groups of an alcoholic hydroxyl group-containing polymer with a photosensitive group-containing acid chloride such as (meth) acrylic acid chloride or cinnamic acid chloride, and ring-opening addition of an acid anhydride to the remaining hydroxyl groups. An isocyanate group-containing (meth) acrylate is added to a part of the hydroxyl groups of the hydroxyl group-containing polymer, and an acid anhydride is ring-opened and added to the remaining hydroxyl groups, a copolymer of styrene and p-hydroxyphenylmaleimide, and polyvinylphenol. Or a copolymer thereof, a part of a hydroxyl group in a phenolic hydroxyl group-containing polymer such as a novolac type phenol resin or a novolac type cresol resin, with an isocyanate group-containing (meth) acrylate added,
Examples thereof include those obtained by adding an isocyanate group-containing (meth) acrylate to a part of the hydroxyl groups of epoxy (meth) acrylate and ring-opening addition of an acid anhydride to all or part of the remaining hydroxyl groups.

Among these, a polymer obtained by ring-opening addition of a compound having a glycidyl group such as glycidyl (meth) acrylate and a C = C unsaturated double bond to the acrylic copolymer of It is preferable because it has excellent properties and also has excellent interlayer insulation resistance and heat resistance when cured to form an insulating layer.

The term "high heating fluidity" means that the copper-clad insulating sheet or the resin side of the insulating sheet is superposed on the surface of the inner layer panel having the conductor circuit pattern on the surface, and is heated and laminated,
In particular, heating in the process of laminating with a hot roll and laminating the whole, that is, the resin composition is melted in the range of about 60 to 120 ° C., and easily flows out between the conductor circuit patterns of the inner layer panel to fill the concave portions of the pattern. Indicates that you can.

The heat fluidity of the resin composition is mainly determined by the molecular weight of the base resin and is influenced by the type and amount of the crosslinking agent. That is, the smaller the molecular weight of the base resin, the greater the fluidity of the resin before curing is used, and the greater the amount of the crosslinking agent, the greater the fluidity of the resin composition upon heating.

The first and second resin compositions used in the present invention are preferable because the adhesion between both layers obtained by using the same type of base resin is good, and the same type in which the heating fluidity is changed by changing the molecular weight. It is preferable to use the base resin of 1.

The second resin composition has high heat fluidity,
The first resin composition is preferably small, and in particular, the first resin is applied to the resin side of the insulating sheet obtained by applying the second resin composition onto the release film and drying it, and to the roughened surface of the copper foil. When the resin side of the copper-clad insulation sheet having the composition layer formed thereon is laminated and the copper-clad insulation sheet having the obtained first and second resin composition layers is laminated on the inner layer panel by heating. , Second
The resin composition (1) has high heat fluidity, and the first resin composition has low heat fluidity. Further, the resin side of the insulating sheet obtained by applying the second resin composition on the release film and drying it is heat-laminated on the inner layer panel, and the first resin composition is formed on the roughened surface of the copper foil. When the resin side of the copper clad insulating sheet on which the product has been formed is laminated, it is essential that the second resin composition has high heat fluidity.

The base resin constituting the first resin composition used in the present invention preferably has a molecular weight (styrene-equivalent weight average molecular weight by gel permeation chromatography) in the range of 10,000 to 200,000, More preferably, it is 30,000 to 100,000. If the molecular weight is too small, the fluidity during heating will be too large, and if it is too large, the alkali solubility will be poor.
The base resin that constitutes the second resin composition preferably has a molecular weight of 1,000 to 50,000, more preferably 5,000 to 30,000. If the molecular weight is too small, the heat resistance, water resistance, etc. will deteriorate, and if it is too large, the fluidity during heating will be too small.

The acid value of the base resin is 0.2 to 10.0.
The range of meq / g is preferable, and more preferably 0.4 to
5.0 meq / g, more preferably 0.6 to 3.0 m
eq / g. If the acid value is too small, the alkali solubility will be poor, and if it is too large, the water resistance will tend to be poor, and neither is preferred.

The proportion of (meth) acrylic acid in the acrylic copolymer is preferably 25 to 60 mol% of all the monomers constituting the copolymer.

Also used in an acrylic copolymer (meth)
The vinyl-based monomer other than acrylic acid and (meth) acrylic acid ester is preferably contained in an amount of 25 mol% or less based on all monomers constituting the copolymer.

Examples of the compound having a glycidyl group and a C = C unsaturated double bond include glycidyl (meth) acrylate, allyl glycidyl ether, vinylbenzyl glycidyl ether and 4-glycidyloxy-3,5-.
Examples thereof include dimethylbenzyl acrylamide, and among these, glycidyl (meth) acrylate is preferable from the viewpoint of easy addition reaction to an acid.

The compound having a glycidyl group and a C = C unsaturated double bond imparts photosensitivity and heat resistance to the base resin. The addition amount of the compound having a glycidyl group and a C = C unsaturated double bond is preferably 10 to 25 mol% based on 100 mol% of all monomers constituting the acrylic copolymer. When it is less than 10 mol%, heat resistance and moisture resistance are not sufficiently exhibited, and when it exceeds 25 mol%,
Any amount of (meth) acrylic acid will be contained in the acrylic copolymer, and the physical properties of the base resin will be deteriorated.

It is preferable to add a photocurable compound and / or a thermosetting resin to the first and second resin compositions of the present invention as a crosslinking agent (adhesive reinforcing agent),
The amount is 20 to 12 with respect to 100 parts by weight of the base resin.
0 parts by weight is preferred. As a photo-curable compound (meta)
A compound having an acryloyl group is preferable, and examples thereof include monofunctional compounds such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl acrylate.
Hydroxypropyl acrylate; as bifunctional compounds, urethane acrylate, 1,3-butanediol diacrylate, polyester acrylate, 1,4-
Butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate; polyfunctional compounds include trimethylolpropane triacrylate. Acrylate, pentaerythritol triacrylate,
Dipentaerythritol hexaacrylate and the like can be mentioned, and these can also be used as an adduct or a condensate.
Further, as the thermosetting resin, urethane resin, epoxy resin, polyester resin, alkyd resin, silicone resin,
Phenolic resins, melamine resins, urea resins and the like can be mentioned.

As the crosslinking agent, urethane acrylate and / or pentaerythritol triacrylate are preferable. Urethane acrylate has a function of particularly improving the adhesion between the surface copper foil and the layer of the resin composition, and pentaerythritol triacrylate has a function of particularly improving the heat resistance of the resin composition after curing.

As reaction initiators for curing active energy rays such as ultraviolet rays and electron beams, benzoin ether type benzyl, benzoin, benzoin alkyl ether, 1-hydroxycyclohexyl phenyl ketone; ketal type benzyl dialkyl ketal; acetophenone type 2,2 '-Dialicoxyacetophenone, 2-hydroxyacetophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone,
Benzophenone, benzophenone, 4-chlorobenzophenone, 4,4'-dichlorobenzophenone,
4,4'-bisdimethylaminobenzophenone, methyl o-benzoylbenzoate, 3,3'-dimethyl-4-methoxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, dibenzosuberone, benzdimethylketal; thioxanthone system As thioxanthone,
2-chlorothioxanthone, 2-alkylthioxanthone, 2,4-dialkylthioxanthone, 2-alkylanthraquinone, 2,2′-dichloro-4-phenoxyacetone and the like can be mentioned, and the compounding amount thereof is base resin 10.
0.5 to 10 parts by weight is preferable with respect to 0 parts by weight. 0.
If it is less than 5 parts by weight, the reaction is not sufficiently initiated, and if it exceeds 10 parts by weight, the resin layer becomes brittle. When the curing is performed using an electron beam among the active energy rays, this polymerization initiator may be omitted.

As the sensitizer at the time of curing the active energy rays, Nisso Cure EPA and EM manufactured by Shin Nisso Kako Co., Ltd.
A, IAMA, EHMA, MABP, EABP, etc., and Kayacure EPA, DETX, DMB manufactured by Nippon Kayaku Co., Ltd.
I, etc., Warn Blenkinsop Qun
tacure EPD, BEA, EOB, DMB, etc.,
Examples include DABA manufactured by Osaka Organic Chemical Co., Ltd., PAA, DAA manufactured by Daito Chemical Co., Ltd., and the like. The addition amount is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the base resin. If it is less than 0.5 part by weight, the reaction rate of the active energy curing does not improve, and if it exceeds 10 parts by weight, the reaction becomes faster.
Reduces shelf life. When used with electron beam irradiation, this sensitizer may be omitted.

As the curing agent, peroxides are preferable, and among them, alkyl peroxides such as dibutyl peroxide, butyl cumyl peroxide, dicumyl peroxide or aryl peroxides are preferable from the viewpoint of storage stability. The amount is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the base resin. If it is less than 0.1 parts by weight, the curing time will be long, and if it exceeds 10 parts by weight, the shelf life will be shortened and the workability will be poor. A curing agent is not necessarily required when curing by electron beam irradiation, but it is preferable to add a curing agent in order to improve adhesion stability such as copper foil adhesion stability and solder heat resistance.

As the organic solvent used for coating the first and second resin compositions used in the present invention, ethers such as diglyme, esters such as ethyl carbitol acetate, ethyl cellosolve acetate and isopropyl acetate, methyl ethyl ketone, Examples thereof include ketones such as cyclohexanone and alcohols such as isopropyl alcohol and ethyl alcohol. The amount of the organic solvent added varies depending on the coating method, but the solid content of the resin composition is 10
As 0% by weight, addition of 20 to 80% by weight is preferable.

In the method for manufacturing a multilayer printed wiring board of the present invention, there is a step of first forming a copper clad laminate panel in which copper foil is laminated on an inner layer panel via an insulating layer. As a means for this, a copper-clad insulating sheet obtained by directly applying the second resin composition to the inner layer panel and drying it, and then forming the first resin composition on the roughened surface of the copper foil. The resin side of the insulating sheet obtained by coating and drying the second resin composition on the release film, A method of laminating the resin side of a copper clad insulating sheet obtained by heating and laminating on a panel for inner layer, and forming a layer of the first resin composition on the roughened surface of the copper foil (hereinafter referred to as "copper clad laminating" The second manufacturing method of the plate panel "), and the resin side of the insulating sheet formed by applying the second resin composition onto the release film and drying the first and the second side on the roughened surface of the copper foil. The first and second resin sets obtained by laminating the resin side of a copper clad insulating sheet formed by forming a layer of the resin composition of Method of heating the laminated copper-clad insulating sheet on the inner layer panel having a layer of the object (hereinafter referred to as "third production method of the copper-clad laminate panel".) It is. In addition, it is preferable to use roll laminating as a laminating means in each step because it can be continuously performed and productivity is good. Further, the use of hot roll lamination is more preferable because it reduces the entrainment of bubbles.

Next, an etching resist is formed at a predetermined position on the copper foil of the obtained copper-clad laminate panel, and the surface thereof is selectively etched to correspond to a specific conductor circuit pattern of the inner layer panel. Make a small hole in the copper foil. The exposed layer of the resin composition is dissolved in an alkaline solution to expose the conductor pattern of the inner layer panel, and the first and second resin composition layers are cured, and then the conductor circuit pattern and the surface of the inner layer panel are formed. The copper foil is electrically conductive with a conductive material. Thereafter, if necessary, the outermost copper foil is selectively etched to form a predetermined pattern, whereby a multilayer printed wiring board having a blind via hole can be manufactured.

The inner layer panel used in the present invention has a conductor circuit pattern on one side or both sides. The resin composition is applied to one side or both sides of the panel, or an insulating sheet or a copper clad insulating sheet is laminated. To use.

For coating the resin composition, a bar coater, a curtain coater, a roll coater, screen printing or the like can be adopted. An organic solvent and, if necessary, a filler are added to the resin composition to prepare a viscosity suitable for the coating method.

The thickness between the conductor circuit pattern surface of the inner layer panel and the surface copper foil is preferably 30 to 60 μm. 30μ
If it is less than m, insulation resistance and withstand voltage between layers cannot be secured,
If it exceeds 60 μm, the undercut becomes large due to alkali dissolution when forming a small diameter blind via hole,
It is difficult to obtain reliability of electrical connection between layers by the conductive material, which is not preferable.

In the copper-clad insulating sheet used in the present invention,
The thickness of the layer of the first resin composition applied and formed on the copper foil is 3
0 to 60 μm is preferable. The thickness of the layer of the second resin composition may be selected according to the thickness of the conductor circuit pattern of the inner layer panel to be used. For example, when it is applied directly to the inner layer panel, it may be applied so that the thickness after drying can embed the copper foil of the conductor circuit pattern. Preferably, the surface of the resin composition layer after coating has smoothness and is coated so as to have approximately the same thickness as the copper foil. When the release film is coated with the second resin composition and dried, and heat laminated on the inner layer panel, for example, if the copper foil of the conductor circuit pattern of the inner layer panel has a thickness of 18 μm, it is dried. The second resin composition layer may be formed on the release film so as to have a thickness of 15 to 20 μm, and is preferably 25 to 40 μm in the case of a 35 μm copper foil.

In the copper-clad insulating sheet in which the first and second resin compositions are applied and dried, the total thickness of the resin composition layers becomes large, and the organic solvent in the layers is completely evaporated. It is difficult to get it done. Therefore, when the layer of the resin composition is cured only by thermosetting, small bubbles may be generated. According to the present invention, since the layer obtained by applying only the first resin composition and the layer obtained by applying only the second resin composition are both thin, the solvent is evaporated in a short drying time. And can be cured without generating bubbles even only by heat curing.

In the second method for producing a copper-clad laminate panel or the third method for producing a copper-clad laminate panel, an insulating sheet provided with a layer of the second resin composition on the release film, or the first and second sheets. When the speed is increased when laminating a copper clad insulating sheet having a layer of the resin composition on a copper foil on an inner layer panel by heating rolls, bubbles are trapped due to a step of the conductor circuit pattern on the panel surface. Sometimes. However, in the second method for producing a copper clad laminate panel, an insulating sheet provided with a layer of the second resin composition on a release film is first laminated on the panel, then a heating step is added again, and then the first step is performed.
By laminating a copper clad insulating sheet having a layer of the resin composition on a copper foil, the entrapped air bubbles can be removed.

In the first method for producing a copper clad laminate panel, the surface has smoothness when the second resin composition is applied to the inner layer panel, but the resin is present on the conductor circuit pattern and other portions. Since the thickness of the composition and the amount of the evaporated organic solvent are different and the resin composition flows, the upper portion of the conductor circuit pattern tends to be convex after drying. These irregularities also affect the surface copper foil, which may make it difficult to form a high-density pattern. On the other hand, in the second method for producing a copper clad laminate panel, the insulating sheet formed by applying the second resin composition in advance has already evaporated the organic solvent, so if it is laminated on the inner layer panel, Since the resin composition of 2 has a large heating fluidity, the resin composition flows between the conductor circuit patterns and on the substrate surface of the panel for the inner layer to eliminate voids and smooth the surface of the resin composition layer. Therefore, it is more suitable for a printed wiring board that requires a high-density pattern.

The insulating sheet and / or the copper-clad insulating sheet used in the method for producing a multilayer printed wiring board of the present invention can be continuously laminated on an inner layer panel or the like if wound in a roll shape via a release paper. preferable. For example, in the second method for producing a copper clad laminate panel, an insulating sheet coated with a second resin composition on a release film and wound in a roll can be used to continuously laminate the inner layer panel with a heat roll. . When a layer of the first resin composition is formed on the copper foil, and a roll-shaped copper-clad insulating sheet wound in a roll through a release film or release paper is used, the inner layer panel is continuously used. It can be roll-laminated continuously.

In the copper-clad insulating sheet used in the present invention, a layer of the resin composition is formed on the mat surface of the copper foil, and a photosensitive resin is previously applied on the copper foil on the opposite surface of the copper foil. You can also leave it. The photosensitive resin can be used in place of the dry film or the etching resist after laminating the copper clad insulating sheet on the inner layer panel, and the step of forming the dry film or the etching resist can be omitted in the manufacturing process of the multilayer printed wiring board. . Not only the economic efficiency is improved, but also the yield is improved by using this method, so that it can be superior in terms of quality.

In the method for producing a multilayer printed wiring board of the present invention, the layer of the resin composition is cured mainly by heating, but it may be cured by electron beam. The temperature in the case of heating is preferably in the range of 80 to 180 ° C, more preferably 150 to 170 ° C. If the temperature exceeds 180 ° C by heat curing, the insulating resin that composes the inner layer panel will deteriorate,
If the temperature is lower than 0 ° C, it takes a long time to cure, and the crosslinking may be insufficient, resulting in insufficient insulation resistance.

When the diameter of the blind via hole becomes smaller, the resin composition on the peripheral wall of the hole flows out at the time of heating, and in the part where much flow occurs, the resin covers the surface of the conductor circuit pattern of the lower inner layer panel, and the blind Even if the via hole is plated, a defect in which continuity cannot be obtained occurs. Therefore, ultraviolet irradiation or electron beam irradiation is performed in a state where the resin composition starts to flow by heating, and an active energy ray is applied to the resin composition below the via hole opened in the copper foil or in the portion facing the via hole. By advancing the curing of the resin composition, it is possible to form a weir for the resin flow and prevent the resin composition from flowing more than necessary. In the case of electron beam irradiation, 10 to 30M at 180 to 300kV
The condition of rad is good, and not only the resin composition layer on the peripheral wall of the blind via hole is cured but also the resin composition layer under the 18-35 μm thick copper foil is cured by the electron beam penetrating the copper foil. Can be made.

When the copper clad insulating sheet or the insulating sheet having the layer of the resin composition used in the method for producing a multilayer printed wiring board of the present invention is laminated on the inner layer panel, the resin composition layer and the inner layer conductor circuit pattern are formed. In order to secure the adhesive strength of the above, it is preferable to subject the pattern surface to a roughening treatment, a black oxide treatment, a brown oxide treatment, a red oxide treatment and the like.

In the method for producing a multilayer printed wiring board of the present invention, the layer of the resin composition for forming the blind via hole can be dissolved with an organic solvent, but using an alkaline aqueous solution improves reliability of the via hole and It is more preferable in terms of workability. Because when the layer of the resin composition is dissolved in an organic solvent, it is a swelling and dissolution reaction,
There is a problem that the boundary of the resin after dissolution becomes not smooth but rough, and the organic solvent remains in the vicinity of the boundary. Therefore, when the blind via hole obtained by dissolving the layer of the resin composition is plated, the effect of the residual organic solvent and the rough boundary of the resin make it difficult for the electroless plating to deposit and to prevent pinholes in the plating. Even in a blind via hole that has been generated and plated, residual organic solvent evaporates and problems such as voids, bubbles, and blistering occur, which prevent electrical and mechanical connection between the conductor circuits between layers due to the blind via hole. This is because it is stable and connection reliability cannot be obtained.

On the other hand, when the layer of the resin composition is dissolved in an alkaline aqueous solution, the carboxyl group reacts and dissolves, so that the dissolution rate is fast, and the resin is sequentially dissolved from the portion in contact with the alkaline aqueous solution, so that the boundary of the resin is Be clear.
In addition, if the resin is dissolved in an alkaline aqueous solution and then washed with an acid, the alkaline component does not remain, the deposition of the electroless plating afterwards is good, and defects such as voids, bubbles, and blisters do not occur, so that reliability is improved. A high blind via hole can be formed.

Further, it is more preferable in that a multilayer printed wiring board having a blind via hole can be easily manufactured in the conventional manufacturing process of a printed wiring board without deteriorating the working environment like an organic solvent. In other words, when an alkali-soluble etching resist is used when forming microscopic holes in the surface copper foil, the resin underneath the microscopic holes in the copper foil is simultaneously formed with the resist in the film stripping process after copper foil etching. The layer of composition can be dissolved. Further, when the alkali development type dry film is used as a resist, it is possible to dissolve and remove the resin composition layer under the fine holes of the copper foil at the same time as removing the resist with an aqueous sodium hydroxide solution for stripping. .

When a layer of a resin composition having an alkali-soluble group such as a carboxyl group is dissolved in an aqueous alkali solution, the alkali content that has reacted with the carboxyl group remains, resulting in corrosion of copper and deterioration of electrical characteristics. After dissolution, it is desirable to wash with acid such as dilute sulfuric acid.
When the copper wiring pattern of the inner layer panel is blackened, if the blind via holes are neutralized with an acid, the oxide film of the blackening treatment will be dissolved and copper color will appear. When the resin remains on the surface of the blackening treatment film, the color of copper cannot be seen, and therefore the quality of the alkali dissolution can be judged by this neutralization treatment. Alternatively, a dye such as methylene blue may be used to detect the presence or absence of residual resin.

In the method for producing a multilayer printed wiring board according to the present invention, a copper foil is etched to form fine holes, and the resin composition layer under the fine holes is dissolved with an alkaline aqueous solution to expose the inner layer panel. As a method for electrically connecting the conductor circuit pattern and the surface copper foil to each other, electroless plating and / or electrolytic plating, conductive paste such as gold, silver, copper and solder is screen-printed, dispenser, pin-printed, etc. It is possible to use a method such as coating by applying the composition and drying and curing.

In the method for manufacturing a multilayer printed wiring board according to the present invention, in the step of forming a blind via hole by dissolving a resin composition in an alkaline solution by forming fine holes in a copper foil by etching, a conventional machining method is used. Grooves similar to V-cut processing and U-cut processing can be collectively provided. If the panel thickness for the inner layer is 0.5 mm or less and the total layer of the first and second resin compositions is 50 μm or more, a groove of 0.1 to 0.3 mm is provided to easily cut by hand. it can.

[0063]

EXAMPLES (Synthesis Example 1 of Base Resin) 30 parts by weight of n-butyl methacrylate, 13 parts by weight of methyl methacrylate, 10 parts by weight of styrene, 5 parts by weight of hydroxyethyl methacrylate, 42 parts by weight of methacrylic acid, 1 part by weight of azobisisobutylnitrile. The mixture of 10 parts by weight was added dropwise to 120 parts by weight of propylene glycol monomethyl ether kept at 80 ° C. in a nitrogen gas atmosphere over 5 hours.
Then, after aging for 1 hour, 0.5 parts by weight of azobisisobutylnitrile was further added and aging for 2 hours to synthesize a carboxyl group-containing methacrylic resin. Next, while blowing in air, 20 parts by weight of glycidyl methacrylate, 1.5 parts by weight of tetrabutylammonium bromide, and 0.15 parts by weight of hydroquinone as a polymerization inhibitor are added and reacted at a temperature of 80 ° C. for 8 hours to give a molecular weight of 50,
000 to 70,000, acid value 1.9 meq / g, unsaturated equivalent 0.81 mol / kg having a carboxyl group 1st
Was synthesized.

(Synthesis example 2 of base resin) n-butyl acrylate 49.5 parts by weight, styrene 9 parts by weight, hydroxyethyl methacrylate 9 parts by weight, methacrylic acid 3
A mixture of 2.5 parts by weight, 2 parts by weight of azobisisobutylnitrile and 2 parts by weight of dodecyl mercaptan as a chain transfer agent was added dropwise to 120 parts by weight of isopropyl alcohol kept at 90 ° C. in a nitrogen gas atmosphere over 5 hours. did. Thereafter, after aging for 1 hour, 1 part by weight of azobisisobutylnitrile was further added and aging was performed for 2 hours to synthesize a carboxyl group-containing methacrylic resin. Then, while blowing air, glycidyl methacrylate 20
Parts by weight, tetrabutylammonium bromide 1.5 parts by weight, and 0.15 parts by weight of hydroquinone as a polymerization inhibitor are further added and reacted at a temperature of 100 ° C. for 8 hours to give a molecular weight of 6,000 to 8,000 and an acid value of 1. A second base resin having a carboxyl group of 9 meq / g and an unsaturated equivalent of 1.14 mol / kg was synthesized.

(Preparation of Resin Composition) 65 parts by weight of the base resin of Synthesis Example 1 prepared as described above and 20 parts by weight of pentaerythritol triacrylate (Aronix M-305 manufactured by Toagosei Kagaku Kogyo Co., Ltd.) as a crosslinking agent. Parts and 15 parts by weight of urethane acrylate (Aronix M-1600 manufactured by Toagosei Co., Ltd.), 1.0 part by weight of dicumyl peroxide as a curing agent, and 50 parts by weight of methyl ethyl ketone as a diluting solvent are mixed well to prepare a first mixture. A resin composition was prepared. A second resin composition was prepared under the same conditions except that the base resin was changed to that of Synthesis Example 2.

(Manufacturing Method of Multilayer Printed Wiring Board) A manufacturing method of a multilayer printed wiring board having a blind via hole using the copper clad insulating sheet of the present invention will be described with reference to the drawings. 1 to 10 are schematic cross-sectional views for explaining a manufacturing process and a structure of a multilayer printed wiring board according to the present invention.

(Preparation of Copper Clad Insulation Sheet) The first resin composition having a viscosity of 3000 cps was applied to the roughened surface of the copper foil 1 having a thickness of 35 μm by a bar coater and dried at 70 ° C. for 13 minutes. . The residual amount of the solvent was 0.05% or less, and a copper-clad insulating sheet 4 having a thickness of the resin composition layer 2 of 40 μm was obtained.

(Preparation of Insulating Sheet) A second resin composition having a viscosity of 2000 cps was applied to the surface of a release film 5 made of polyester having a thickness of 50 μm as a release film by a bar coater and dried at 70 ° C. for 8 minutes. The residual solvent amount is 0.05% or less, and the thickness of the resin composition layer 3 is 30% or less.
An insulating sheet 13 of μm was obtained.

(Example 1) An inner layer panel 7 was prepared in which a copper wiring pattern 6 was formed at a predetermined position by selective etching on a 0.6 mm glass epoxy double-sided copper clad plate having a copper foil 1 having a thickness of 35 μm. Then, the surface of the copper wiring pattern 6 of the inner layer panel 7 is treated with a solution containing 37 g / liter of sodium chlorite, 10 g / liter of sodium hydroxide, and 20 g / liter of trisodium phosphate dodecahydrate.
It was treated at 95 ° C. for 5 minutes, washed well with water, dried, and blackened.

On both surfaces of the inner layer panel, the insulating sheet 13 obtained by applying the second resin composition on the release film and drying it,
The release film was peeled off by laminating with a metal roll at 75 ° C. After heating at 90 ° C. for 5 minutes, the copper-clad insulation sheet 4 coated with the first resin composition is continuously applied onto the layer 3 of the second resin composition on both surfaces of the inner layer panel with a metal roll at 75 ° C. It laminated and produced the copper clad laminated board panel (FIGS. 1-3).

The surface of the copper foil 1 of the above-mentioned copper clad laminate panel can be alkali-printed on the surface of the copper foil 1 by screen printing or photo method except for the portions where the fine holes 8 of 0.3 to 0.5 mmφ are formed. A solution type etching resist 12 was formed, and the copper in the fine holes of the copper foil was etched with a cupric chloride solution (FIG. 4). Then 40 1 wt% sodium carbonate solution ℃ a spray pressure of 1.5 kg / cm ^2, the layer 2 of the first resin composition of the underlying part of the small holes 8 of the copper foil is dissolved and removed by The underlying copper wiring pattern 6 was exposed to form a blind via hole 9 and at the same time, the etching resist was removed (FIG. 5).

Then, after washing with water and 10% sulfuric acid aqueous solution, preheating at 100 ° C. for 30 minutes and then at 150 ° C. for 30 minutes
Baking for 1 minute to form layer 2 of the first resin composition and second
The resin composition layer 3 was cured. After that, as shown in FIG. 6, a through hole 10 which requires connection between the copper wiring pattern 6 of the inner layer panel and the copper foil 1 of the outer layer is drilled, and the blind via hole and the through hole are formed as shown in FIG. Was simultaneously plated to form an etching resist 12 as shown in FIGS. 8, 9 and 10, and etching and film stripping were performed to obtain a multilayer printed wiring board having blind via holes. No bubbles were observed in the resin composition layer, and the surface copper foil was smooth.

Of the printed wiring board prepared as described above.
65 ° C 30 minutes, 125 ° C 30 minutes as one cycle thermal cycle test, soldering heat resistance test at 260 ° C for 3 minutes and 280 ° C for 60 seconds in a 25 mm square pattern, pressure cooker test (130 ° C, 85% RH, 100 hours,
No abnormality was found in any of the interlayer withstand voltage tests under a DC20V bias).

(Example 2) The second resin composition was applied by screen printing to one surface of the inner layer panel 7 having the copper wiring pattern 6 subjected to the same blackening treatment as in Example 1 and dried at 70 ° C for 7 minutes. . The thickness of the resin composition is 10 on the copper wiring pattern.
The thickness was 35 μm on the insulating substrate of the inner layer panel. Similarly, the other surface was coated with the second resin composition and dried. Subsequently, the copper clad insulating sheet 4 coated with the first resin composition is laminated on the layer 3 of the second resin composition on the surface of the inner layer panel with a metal roll at 75 ° C. to form a copper clad sheet having a smooth surface. A laminated panel was created.

Thereafter, in the same manner as in Example 1, minute holes of copper foil were formed, and the underlying layer of the first resin composition was dissolved and removed to expose the underlying copper wiring pattern to form a blind via hole. Is formed, the resin composition is cured, the through hole is drilled, the blind via hole and the through hole are plated at the same time, and the circuit is formed on the surface.
A multilayer printed wiring board having blind via holes was obtained. Although no bubbles were observed in the resin composition layer, the surface copper foil was affected by the conductor circuit pattern of the inner layer panel and was slightly wavy.

Of the printed wiring board prepared as described above.
65 ° C. 30 minutes 125 ° C. 30 minutes as one cycle thermal cycle test, soldering heat resistance test at 260 ° C. for 3 minutes and 280 ° C. for 60 seconds in a 25 mm square pattern, pressure cooker test (130 ° C., 85% RH, 100 hours, D
No abnormality was found in the interlayer withstand voltage test by C20V bias).

Example 3 An insulating sheet 13 in which a second resin composition was applied and dried on a release film and a copper-clad insulating sheet 4 in which the first resin composition was applied were placed in a rubber roll 7
The layers were laminated at 0 ° C. and an air pressure of 0.5 to 1 kg / cm ² to prepare a copper-clad insulating sheet having layers of the first and second resin compositions. The copper clad insulating sheet 13 was laminated on both surfaces of the inner layer panel having the same blackened copper wiring pattern 6 as in Example 1 with a metal roll at 75 ° C. to prepare a copper clad laminate panel.

Thereafter, as in Example 1, minute holes of copper foil were formed, and the underlying layer of the first resin composition was dissolved and removed to expose the underlying copper wiring pattern to form a blind via hole. Is formed, the resin composition is cured, the through hole is drilled, the blind via hole and the through hole are plated at the same time, and the circuit is formed on the surface.
A multilayer printed wiring board having blind via holes was obtained. No air bubbles were observed in the resin composition layer, but there were slight air bubbles caught during lamination between the substrates of the second resin composition layered inner layer panel. The surface of the copper foil was smooth.

Of the printed wiring board prepared as described above.
65 ° C 30 minutes 125 ° C 30 minutes as a cycle of thermal cycle test, pressure cooker test (130 ° C,
No abnormality was found in the inter-layer dielectric breakdown voltage test under 85% RH, 100 hours, DC20V bias). In the solder heat resistance test, it is 26 in a 25 mm square pattern.
There was no abnormality at 0 ° C. for 3 minutes and 280 ° C. for 20 seconds, but slight blistering occurred at 280 ° C. for 60 seconds.

[0080]

According to the manufacturing method of the present invention, the physical characteristics,
A multilayer printed wiring board having a blind via hole with excellent electrical characteristics and reliability can be obtained. Moreover, since blind via holes can be easily and collectively formed by etching copper foil and dissolving the resin composition with an alkaline aqueous solution, productivity is greatly improved compared to the conventional drilling process in which holes are drilled. It will be improved. Also,
Regardless of variations in the depth of the conductor pattern on the inner layer panel, the blind via hole can be surely provided by dissolving the layer of the resin composition up to the conductor pattern on the inner layer panel. The blind via hole connection failure is eliminated, and there is no short circuit failure that is erroneously connected to the conductor pattern of the other layer for the inner layer. Further, since the prepreg used between the inner layer panel and the outer copper foil can be reduced, the thickness of the printed wiring board can be reduced, so that a high-density multilayer printed wiring board can be obtained.

Since the first and second resin compositions are applied separately, the total application time can be shortened. And
Since curing can be performed without generating bubbles only by heating, the manufacturing process of the multilayer printed wiring board can be reduced, and a large and expensive electron beam irradiation device is not required. Therefore, it is extremely useful because it enables the manufacture of a multilayer printed wiring board which requires blind via holes used for high-density mounting in various electronic devices.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration before roll-laminating an inner layer panel 4 having a copper wiring pattern 6 on its surface and an insulating sheet 13 in a manufacturing process of a multilayer printed wiring board according to a second embodiment of the present invention. is there.

FIG. 2 is a schematic cross-sectional view showing the configuration before laminating the copper clad insulating sheet 4 after laminating the insulating sheet 13 and removing the release film 5 in the same manufacturing process.

FIG. 3 is a schematic cross-sectional view showing a configuration after roll-laminating the copper clad insulating sheet 4 on the inner layer panel in the same manufacturing process.

FIG. 4 is a schematic cross-sectional view showing a configuration after forming fine holes in a copper foil on the surface by etching in the same manufacturing process.

FIG. 5 is a schematic cross-sectional view showing a configuration after the layer of the resin composition in the lower part of the copper foil microholes is dissolved in the same manufacturing process.

FIG. 6 is a schematic cross-sectional view after forming a through hole by drilling in the same manufacturing process.

FIG. 7 is a schematic cross-sectional view after a plating process in the manufacturing process.

FIG. 8 is a schematic cross-sectional view after forming an etching resist for etching the outer layer copper foil pattern in the manufacturing process.

FIG. 9 is a schematic cross-sectional view after etching unnecessary copper foil of the outer layer in the same manufacturing process.

FIG. 10 is a schematic cross-sectional view after removing the etching resist in the same manufacturing process.

FIG. 11 is a schematic cross-sectional view showing a structure before thermocompression bonding an inner layer panel having a copper wiring pattern on the surface and a copper foil through a prepreg in the manufacturing process of a conventional multilayer printed wiring board having a blind via hole. It is a figure.

FIG. 12 is a schematic cross-sectional view showing the configuration of a copper-clad laminate panel after being subjected to thermocompression bonding in the same manufacturing process.

FIG. 13 is a schematic cross-sectional view showing the copper clad laminate panel after forming blind via hole holes by drilling in the same manufacturing process.

FIG. 14 is a schematic cross-sectional view showing the copper clad laminate panel after forming through holes by drilling in the manufacturing process.

FIG. 15 is a schematic cross-sectional view after a plating process in the manufacturing process.

FIG. 16 is a schematic cross-sectional view after forming an etching resist in the manufacturing process.

FIG. 17 is a schematic cross-sectional view after unnecessary copper foil is removed by etching in the manufacturing process.

FIG. 18 is a schematic cross-sectional view after removing the etching resist in the same manufacturing process.

FIG. 19 is a schematic cross-sectional view showing a configuration before roll-laminating an inner layer panel having a copper wiring pattern on its surface and a copper clad insulating sheet in the manufacturing process of a multilayer printed wiring board using a conventional copper clad insulating sheet. It is a figure.

FIG. 20 is a schematic cross-sectional view showing the configuration after roll-laminating the copper clad insulating sheet on the inner layer panel in the same manufacturing process.

FIG. 21 is a schematic cross-sectional view showing the configuration after forming minute holes in the copper foil on the surface by etching in the same manufacturing process.

FIG. 22 is a schematic cross-sectional view showing the configuration after the layer of the resin composition in the lower part of the copper foil microholes is dissolved in the same manufacturing process.

FIG. 23 is a schematic cross-sectional view after forming a through hole by drilling in the same manufacturing process.

FIG. 24 is a schematic cross-sectional view after a plating process in the manufacturing process.

FIG. 25 is a schematic cross-sectional view after forming an etching resist for etching the outer layer copper foil pattern in the same manufacturing process.

FIG. 26 is a schematic cross-sectional view after etching an unnecessary copper foil of the outer layer in the same manufacturing process.

FIG. 27 is a schematic cross-sectional view after removing the etching resist in the same manufacturing process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Copper foil 2 Layer of 1st resin composition 3 Layer of 2nd resin composition 4 Copper-clad insulating sheet 5 Release film 6 Conductor circuit pattern (copper wiring pattern) 7 Inner layer panel 8 Small copper foil Hole 9 Blind via hole 10 Through hole 11 Plating through hole 12 Etching resist 13 Insulating sheet 14 Prepreg 15 Hole for blind via hole 16 Copper clad insulating sheet on which layer of first and second resin composition is formed

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenya Matsumoto Kenya Matsumoto, Aichi Prefecture 1-chome, Funami-cho, Minato-ku, Tochi Gosei Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor Tomio Kanbayashi Nagoya, Aichi Prefecture 1 Toago Synthetic Chemical Industry Co., Ltd. Nagoya Research Institute, Minami-ku Funami-cho 1 (72) Inventor Hideki Hiraoka 1 Touna Synthetic Chemical Industry Co., Ltd. Nagoya Research Laboratories 1 Funami-cho, Minato-ku Nagoya City, Aichi Prefecture Within

Claims (3)

[Claims] 1. An inner layer panel having a conductor circuit pattern on one or both sides is coated with an alkali-soluble second resin composition, the gap between the conductor circuit patterns is filled with the second resin composition, and dried. A step of: laminating the resin side of the copper-clad insulating sheet obtained by applying the alkali-soluble first resin composition on the roughened surface of the copper foil and drying it, on the layer of the second resin composition A step of forming a minute hole by etching at a predetermined position of the copper foil; a step of dissolving the exposed layer of the resin composition with an alkaline solution to expose the conductor circuit pattern of the inner layer panel A method of manufacturing a multilayer printed wiring board comprising a step of curing the layers of the first and second resin compositions; a step of electrically connecting the conductor circuit pattern of the inner layer panel and the copper foil on the surface with a conductive substance. 2. A panel for an inner layer having a conductor circuit pattern on one or both sides of the resin side of an insulating sheet obtained by applying a second resin composition which is soluble in alkali and has high heat fluidity on a release film and drying the resin sheet. Heating and laminating the layers to fill the gaps between the conductor circuit patterns with the second resin composition;
The step of peeling the release film; the resin side of the copper-clad insulating sheet obtained by applying the alkali-soluble first resin composition to the roughened surface of the copper foil and drying the same is used as the second resin composition. A step of laminating on a layer; a step of forming a micro hole by etching at a predetermined position of a copper foil; a layer of the resin composition exposed at the hole portion is dissolved with an alkaline solution to form a conductor circuit pattern of an inner layer panel A method for producing a multilayer printed wiring board, which comprises a step of exposing the first and second resin composition layers; a step of electrically connecting the conductor circuit pattern of the inner layer panel and the copper foil on the surface with a conductive substance. . 3. A layer of the first resin composition of a copper-clad insulating sheet, which is obtained by applying the alkali-soluble first resin composition having a small heating fluidity to the roughened surface of the copper foil and drying it. A first resin composition and a second resin composition are obtained by laminating a second resin composition layer of an insulating sheet obtained by applying a second resin composition that is alkali-soluble and has high heat fluidity onto a release film and then drying it. Of a copper-clad insulation sheet having a layer of a product; a resin side of the copper-clad insulation sheet having a layer of the first and second resin compositions is heat-laminated on an inner layer panel having a conductor circuit pattern on one or both sides. Then, a step of filling a gap between the conductor circuit patterns with a second resin composition; a step of forming a minute hole by etching at a predetermined position of the copper foil; an alkali is applied to the layer of the resin composition exposed in the hole portion. Dissolve in a solution and apply the conductor circuit pattern of the inner layer panel. Of the multilayer printed wiring board, which comprises a step of exposing the resin layer of the first and second resin compositions; a step of electrically connecting the conductor circuit pattern of the inner layer panel and the copper foil on the surface with a conductive material. Production method.