JPH08330740A - Manufacture of multilayered printed-wiring board and etching liquid used for that manufacturing method - Google Patents

Abstract

PURPOSE: To manufacture a multilayered printed-wiring board, which has an IVH and is thinned, without reducing the working atmosphere by a method wherein a cured resin layer under a fine hole is removed with specified etching liquid to expose a conductor circuit on an internal layer board. CONSTITUTION: A thermosetting copper-clad bonding agent sheet 2 formed using a thermosetting epoxy resin composition containing epoxy polymer, which is compounded in such a way that bifunctional epoxy resin and bifunctional halogenated phenols are mixed in the ratio of epoxy group/phenolic hydroxyl group of 1:0.9 to 1.1, has a film formability and has molecular weight of 100000 or more, as its constituent component is superposed on an internal layer board 1 to laminate together. After that, an etching resist 4 is formed on an external layer copper foil, a fine hole is formed by a selective etching and the resist 4 is removed. A cured resin layer under the fine hole is etched away with etching liquid, which consists of amide solvent, an alkaline metal compound and alcoholic solvent, a via hole 5 is opened and a conductor circuit on the internal layer board 1 is exposed.

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 and an etching solution used in the method.

[0002]

2. Description of the Related Art A multilayer printed wiring board is usually heated by a resin prepreg containing glass cloth as a base material between an inner layer board having a circuit formed on the copper clad laminate and a single-sided copper clad laminate or copper foil. It can be obtained by forming a circuit on the outer layer surface of a copper clad laminate with an inner layer circuit, which is heat-cured by applying pressure and bonded and integrated. In recent years, with the miniaturization, high performance, and multi-functionalization of electronic devices, multilayer printed wiring boards have been moving toward higher density. In order to achieve higher density, thinner layers between layers and fine wiring And the diameter of the inter-layer connection hole is further reduced, and an interstitial via hole (hereinafter referred to as IVH) for connecting only adjacent wiring layers is used. This is a situation where a smaller diameter is required.

Here, as shown in FIG. 2 (a), the conventional method for manufacturing a multilayer printed wiring board having IVH includes an inner layer circuit board 1 in which a circuit is formed on a copper clad laminate and a single sided copper clad laminate. Or, a plurality of prepregs 9 are interposed between the copper foil 3 and
By laminating and adhering by heating and pressurizing, they are integrated as shown in FIG. 2 (b), and this integrated copper clad laminate with inner layer circuit is drilled at a predetermined position as shown in FIG. 2 (c). Hole is drilled to reach the inner circuit by
The holes 5 are formed, and if necessary, the conventional through holes 6 are drilled as shown in FIG.
As shown in FIG. 2, electroless copper plating, electrolytic copper plating 7 are performed to connect the inner layer circuit and the outer layer copper foil, and as shown in FIG. 2F, an etching resist 8 is formed on the outer layer copper foil. As shown in FIGS. 2 (g) and 2 (h), etching is selectively performed, and the etching resist is removed as shown in FIG. 2 (i).

Further, conventionally, a method of selectively chemically etching a plastic part to form IVH has been proposed. As a material capable of such chemical etching, Japanese Patent Laid-Open No. 4577/1975 has been proposed. Kaisho 51
As disclosed in JP-A-27464 or JP-A-53-49068, a method of etching with hydrazine or the like using a polyimide film is known. Although not intended to form IVH, a method of surface roughening or desmearing a cured epoxy resin used for a printed wiring board with concentrated sulfuric acid, chromic acid, permanganate, etc. It is known from JP 54-144968 A and JP 62-104197 A.

[0005]

Among such conventional methods, the method of drilling the hole for IVH to the position reaching the wiring circuit in the inner layer is different from the method of drilling the through hole. However, it is impossible to stack and process a plurality of sheets, and it takes a very long time to process one sheet at a time, and there is a problem that productivity is low. Also, in order to control the depth of the drill tip, it is necessary to match the depth of the copper wiring pattern, but the thickness of the multilayer printed wiring board usually has some variation, so the depth of the interlayer When the thickness of the layer is large, it may not reach the wiring circuit in the inner layer, and when the thickness between layers becomes smaller than the set depth, it may reach the wiring circuit in the layer below it. This is the cause of poor continuity due to short circuit. Furthermore, when drilling a small diameter of 0.3 mm or less, because of processing of the core layer of the drill and the resin layer including the glass cloth base material,
There is a problem that the life of the drill is significantly reduced.

Further, in the chemical etching method, hydrazine is highly toxic, or concentrated sulfuric acid, chromic acid, and permanganate are designated as specific chemical substances, which requires equipment such as working environment maintenance. There were problems in terms of cost and safety.

INDUSTRIAL APPLICABILITY The present invention is used for a method of manufacturing a multilayer printed wiring board which has IVH excellent in connection reliability and electrical characteristics, can be thinned, is efficient and does not deteriorate the working environment, and a method for manufacturing the same. An etching solution is provided.

[0008]

Means for Solving the Problems The method for producing a multilayer printed wiring board according to the present invention comprises (1) a bifunctional epoxy resin and a halogenated bifunctional phenol, wherein the compounding equivalent ratio is epoxy group / phenolic hydroxyl group = 1. An epoxy polymer having a molecular weight of 100,000 or more and having a film-forming ability, which is blended so as to be 0.9 to 1.1 and is polymerized by heating in the presence of a catalyst, and a cross-linking agent.
A thermosetting epoxy resin composition having a polyfunctional epoxy resin as a constituent component, a thermosetting copper-clad adhesive resin sheet formed on a copper foil, and an thermosetting copper sheet on an inner layer board on which a conductor circuit is formed in advance. Step of laminating and laminating the resin surfaces of the adhesive sheet for adhesive bonding (2) Step of thermosetting the resin layer of the thermosetting copper-adhesive resin sheet (3) Forming an etching resist on the outer layer copper foil and selectively etching the copper foil Step of forming fine holes in the surface (4) Step of removing etching resist (5) Etching and removing the cured resin layer under the fine holes with an etching solution composed of an amide solvent, an alkali metal compound and an alcohol solvent, Step of making a hole and exposing the conductor circuit of the inner layer board (6) Step of plating for electrically connecting the conductor circuit of the inner layer board and the outer layer copper foil (7) On the outer layer copper foil Tsu quenching resist is formed, characterized by comprising the step of removing the step (8) etching resist to form a wiring circuit on the copper foil surface by selective etching.

The thermosetting epoxy resin composition used in the present invention comprises a film-forming epoxy polymer, a cross-linking agent, and a polyfunctional epoxy resin as constituent components.
Epoxy polymer having film forming ability has a molecular weight of 1
It is a so-called high-molecular-weight epoxy polymer of at least 0,000, and the compounding equivalent ratio of the bifunctional epoxy resin and the halogenated bifunctional phenol is such that epoxy group / phenolic hydroxyl group = 1: 0.9 to 1.1. It is obtained by heating and polymerizing in the presence of a catalyst in an amide or ketone solvent having a boiling point of 130 ° C. or higher at a reaction solid content concentration of 50% by weight or less in the presence of a catalyst.

The bifunctional epoxy resin may be any compound as long as it is a compound having two epoxy groups in the molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, There are aliphatic chain epoxy resins and the like, and several kinds of these compounds can be used together. Further, components other than the bifunctional epoxy resin may be included as impurities.

The halogenated bifunctional phenols may be any compounds as long as they are compounds in which a halogen atom is substituted and have two phenolic hydroxyl groups, such as hydroquinone and resorcinol which are monocyclic bifunctional phenols. Catechol, polycyclic bifunctional phenol bisphenol A, bisphenol F, naphthalenediols,
There are bisphenols and halides such as substituted alkyl groups thereof, and several kinds of these compounds can be used in combination. Further, components other than the halogenated bifunctional phenols may be included as impurities.

The catalyst may be any compound as long as it has a catalytic ability to accelerate the etherification reaction of the epoxy group and the phenolic hydroxyl group, and examples thereof include alkali metal compounds, alkaline earth metal compounds and imidazoles. , Organic phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like. Among them, the alkali metal compound is the most preferable catalyst, and examples of the alkali metal compound include hydroxides of sodium, lithium and potassium, halides, organic acid salts, alcoholates, phenolates, hydrides, borohydrides, and amides. Etc., and these catalysts can be used in combination.

The reaction solvent is preferably an amide solvent or a ketone solvent, and the amide solvent has a boiling point of 13
There is no particular limitation as long as the raw material epoxy resin and phenols are dissolved at 0 ° C. or higher. For example, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N,
There are N-dimethylacetamide, N, N, N ′, N′-tetramethylurea, 2-pyrrolidone, N-methyl-2-pyrrolidone, carbamic acid ester and the like, and these solvents can be used in combination. The ketone solvent can be used in combination with other solvents such as ether solvents, and examples thereof include cyclohexanone, acetylacetone, diisobutyl ketone, phorone, isophorone, methylcyclohexanone, and acetophenone.

As the conditions for synthesizing the polymer, the compounding equivalent ratio of the bifunctional epoxy resin and the halogenated bifunctional phenol is: epoxy group / phenolic hydroxyl group = 1: 0.9-
It is preferably 1.1. The compounding amount of the catalyst is not particularly limited, but generally 0.0001 to 0.2 mol of the catalyst is preferable to 1 mol of the epoxy resin. The polymerization reaction temperature is preferably 60 to 150 ° C, 60 ° C
If it is less than 150 ° C., the high molecular weight reaction is remarkably slow, and if it exceeds 150 ° C., there are many side reactions and the polymer does not linearly increase in molecular weight. The solid content concentration during the polymerization reaction using a solvent is 50%.
The following is preferable, and further 30% or less is more preferable.

As a cross-linking agent for this high-molecular-weight epoxy polymer, a mask obtained by masking (blocking) isocyanates with another compound having active hydrogen, in which the reactivity of the cross-linking agent can be easily controlled and the storage stability of the varnish can be easily ensured. Isocyanates can be used. As such isocyanates, any isocyanate may be used as long as it has two or more isocyanate groups in the molecule. For example, hexamethylene masked with a masking agent such as phenols, oximes and alcohols. Examples thereof include diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and tolylene diisocyanate. In particular, isophorone diisocyanate and tolylene diisocyanate masked with phenols are preferable for improving the heat resistance of the cured product. The amount of the crosslinking agent is 1.0 equivalent of the alcoholic hydroxyl group of the high molecular weight epoxy polymer,
It is preferable that the isocyanate group is 0.1 to 1.0 equivalent.

As a polyfunctional epoxy resin, 2 in the molecule
Any compound having at least one epoxy group may be used, and examples thereof include glycidyl ethers of phenols such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, resol type epoxy resin, and bisphenol type epoxy resin. Epoxy resin, alicyclic epoxy resin, epoxidized polybutadiene, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, isocyanurate type epoxy resin, flexible epoxy resin, etc., and any epoxy resin may be used. However, in particular, a phenol type epoxy resin or a mixture of a phenol type epoxy resin and a polyfunctional epoxy resin is preferable for improving heat resistance. The amount of the polyfunctional epoxy resin is preferably 20 to 100% by weight based on the high molecular weight epoxy polymer. Also,
Since this polyfunctional epoxy resin acts as an adhesive component and a fluid component at the time of molding, it can be adjusted to an appropriate amount depending on the thickness of the inner layer copper foil and the density of the circuit, and used alone or in a mixture of two or more kinds. be able to.

Further, a curing agent and a curing accelerator for the polyfunctional epoxy resin are used for these polyfunctional epoxy resins. Examples of such epoxy resin curing agents and curing accelerators include novolac-type phenol resins, dicyandiamide, acid anhydrides, amines, imidazoles, and phosphines, and these can be used in combination. Further, by adding a silane coupling agent, the adhesive strength of the epoxy adhesive film, particularly the adhesive strength with the copper foil, can be improved, which is preferable.
As such a silane coupling agent, epoxy silane, amino silane, urea silane and the like are preferable.

A varnish containing the above components is applied onto a copper foil and dried by heating to obtain a B-stage thermosetting copper-clad adhesive resin sheet. The thickness of the resin layer depends on the copper foil thickness of the inner layer circuit, but is preferably 25 to 70 μm.

The B-stage thermosetting copper-clad adhesive resin sheet is laminated while the resin surface of the previously prepared inner layer circuit board and the copper-clad adhesive resin sheet are overlapped with each other to obtain a copper clad laminate with an inner layer circuit in the B stage state. Obtainable. The laminating conditions at this time may be 100 ° C. or higher since the resin composition of the copper-clad adhesive resin sheet temporarily adheres at 100 ° C. or higher. Also, the pressure is not particularly limited,
It is preferably ² kg / cm ² or more. In addition, a vacuum may be applied during lamination. Further, the roll is not particularly limited in resin property and metal property, but metal property is preferable because the surface smoothness after lamination is good.

When the resin layer of the copper-clad adhesive resin sheet after lamination is heated and cured at 170 ° C. for 30 minutes or more, the B-stage thermosetting resin is completely cured. In particular, the heating temperature and time affect the degree of curing and cause variations in the etching rate afterwards, so it is necessary to completely cure.

An etching resist is formed on the outer layer copper foil of the copper clad laminate containing an inner layer circuit joined with the obtained thermosetting copper clad adhesive resin sheet, and development / selection is performed by a commonly used photography method. Etching is performed to form fine holes on the copper foil surface. This fine hole becomes an opening of the IVH hole. Then, the etching resist is removed. The cured resin layer under the fine holes is removed by etching with an etching solution containing an amide-based solvent, an alkali metal compound, and an alcohol-based solvent as constituent components to expose the inner layer circuit. The high molecular weight epoxy polymer, which is a constituent of the thermosetting resin composition of the thermosetting copper-clad adhesive resin sheet, is decomposed by alkali.
The etching effect of the cured resin layer is that the skeleton of the high molecular weight epoxy polymer is cleaved and decomposed by the alkali that permeates the cured resin layer along with the amide solvent / alcohol solvent, and the one with a low molecular weight dissolves in the amide solvent. Then etched.

Any amide solvent may be used, but for example, formamide, N-methylformamide, N, N-
Dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N, N,
N ', N'-tetramethylurea, 2-pyrrolidone, N-
Examples include methyl-2-pyrrolidone and carbamic acid ester. Particularly, N, N-dimethylacetamide, N, N-dimethylformamide, and N-methyl-2-pyrrolidone having a large action of dissolving a cured product having a low molecular weight are preferable. Also, a mixed solution of these may be used. Further, it may be used in combination with other solvents such as a ketone solvent and an ether solvent. The ketone solvent that can be used here is
Any substance may be used, for example, acetone, ethyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone,
4-heptanone, diisobutyl ketone, cyclohexanone and the like. The ether solvent that can be used here may be any solvent, for example, dipropyl ether,
Diisopropyl ether, dibutyl ether, anisole, phenetole, dioxane, tetrahydrofuran,
Examples include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether. The concentration is not particularly limited, but the amide solvent is 5
When it exists in the solution at a concentration of 0 to 95% by weight, the decomposition rate and the dissolution rate of the cured product are increased.

Any alkali metal compound may be used,
Alkali metal compounds such as lithium, sodium, potassium, rubidium and cesium, which may be any as long as they are soluble in an alcohol solvent, for example, metals such as lithium, sodium, potassium, rubidium and cesium, and hydrides. , Hydroxide, borohydride, amide, fluoride, chloride, bromide, iodide, borate,
Examples include phosphates, carbonates, sulfates, nitrates, organic acid salts, and phenolic salts. In particular, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferable because of the rapid decomposition rate of the cured product. The concentration is not particularly limited, but if it exists in the solution at a concentration of 0.5 to 15% by weight, the rate of decomposition of the cured product becomes faster, which is preferable.

Any alcohol solvent may be used, but for example, methanol, ethanol, 1-propanol, 2
-Propanol, 1-butanol, 2-butanol, is
o-butanol, tert-butanol, 1-pentanol,
2-pentanol, 3-pentanol, 2-methyl-1
-Butanol, iso-pentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-
Pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, cyclohexanol, 1-
Methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol,
Triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1, Examples include 4-butanediol, 2,3-butanediol, 1,5-pentanediol, glycerin and dipropylene glycol. Several kinds of these solvents can be used in combination.
Methanol, ethanol and diethylene glycol monomethyl ether, which have high solubility of alkali metal compounds,
Diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and ethylene glycol monoethyl ether are preferable, and a mixture thereof may be used. The concentration is not particularly limited, but if present in the solution at a concentration of 4.5 to 35% by weight,
The decomposition rate of the cured product is high, which is preferable.

In the etching liquid composed of the above respective constituents, the contact time between the cured product and the solution and the temperature of the solution depend on the desired etching rate and degree.
It is necessary to set appropriate conditions depending on the VH diameter and thickness. The etching method is not particularly limited to a spray method or a dip method, and any constituent component of the etching solution can be used for etching. After etching, the plating method for electrically connecting the exposed inner layer circuit and outer layer copper foil is
Generally used electroplating is preferable, and electroless copper plating may be used for the small diameter IVH. Further, the electrical connection may be achieved by applying a conductive paste, drying and curing it. Furthermore, an etching resist is formed on the outer layer copper foil, and development / selective etching is performed by a commonly used photography method, a wiring circuit is formed on the outer layer copper foil surface, the etching resist is removed, and the inner layer circuit and the outer layer are formed. A multilayer printed wiring board having circuits connected by IVH is obtained. The multilayer printed wiring board obtained as described above is used as an inner layer, a thermosetting copper-clad adhesive resin sheet is further stacked, and this is repeated to obtain a multilayer printed wiring board connected by IVH of 6 layers or more. You can

[0026]

【Example】

Example 1 A thermosetting copper-clad adhesive resin having a resin layer thickness of 50 μm, in which a resin composition comprising a high molecular weight epoxy polymer, a phenol resin masked diisocyanate, and a cresol novolac type epoxy resin was applied to a roughened surface of a copper foil. Sheet MCF-3
000E (trade name, manufactured by Hitachi Chemical Co., Ltd.) is overlaid on a preliminarily prepared inner layer circuit board and laminated in a vacuum state with a metal roll having a temperature of 130 ° C. and an air pressure of 3 kg / cm ² (FIG. 1 (a)). , And a copper clad laminate with an inner layer circuit in the B stage was obtained (shown in FIG. 1 (b)).
In order to completely cure the resin layer in the B stage state,
It was heated for 30 minutes in a hot air dryer at 170 ° C. An etching resist is formed on the surface of the outer layer copper foil of the copper clad laminate containing the inner layer circuit (shown in FIG. 1 (c)), and the diameter of 50 to 3 is formed at a place where IVH is formed by a photography method.
The 00 μm resist is removed (as shown in FIG. 1D),
Further, the outer layer copper foil at the portion where IVH was formed was removed (shown in FIG. 1 (e)). Then, the etching resist was removed to expose the cured epoxy adhesive film at the place where IVH was desired to be formed (shown in FIG. 1 (f)). Subsequently, N-methyl-2-pyrrolidone 90 heated to 50 ° C.
Wt%, potassium hydroxide 3 wt%, methanol 7 wt%
The cured epoxy adhesive film is etched to expose the inner layer circuit,
A hole for IVH was formed. Here, in the case where the decomposition product was not completely removed, ultrasonic waves were continuously applied to wash the inside of the hole with water (shown in FIG. 1 (g)). Next, the through hole was drilled (shown in FIG. 1 (h)). Continued
In order to electrically connect the inner layer circuit and the outer layer copper foil, the IVH hole and the through hole were plated with 15 to 20 μm of copper (shown in FIG. 1 (i)). Next, an etching resist is formed on the outer layer surface (shown in FIG. 1J), a wiring circuit is formed by selective etching (shown in FIGS. 1K and 1), and the etching resist is removed (shown in FIG. 1K). (Shown in FIG. 1 (m).) A multilayer printed wiring board having four layers was obtained. The electrolytic corrosion resistance test, the solder heat resistance test, and the peel strength of the surface copper foil of the multilayer printed wiring board obtained in the above examples were measured. In the electrolytic corrosion resistance test, a comb pattern having a conductor interval of 0.1 mm was formed in an inner layer circuit, and a change in insulation resistance was measured under the conditions of 120 ° C., humidity 85%, and 100V. The initial value is 10 ¹³ Ω,
It was 10 ¹² Ω after 1,000 hours had passed. The solder heat resistance was not abnormal in the solder float test at 260 ° C. for 3 minutes. The peel strength of the surface copper foil was 1.7 kg / cm.

Example 2 The etching solution of Example 1 was changed to an etching solution containing 50% by weight of N-methyl-2-pyrrolidone heated to 70 ° C., 15% by weight of potassium hydroxide and 35% by weight of methanol, and cured epoxy adhesive was used. As a result of being brought into contact with the film for 30 minutes, it was possible to perform etching, and a similar 4-layer multilayer printed wiring board could be obtained.

Example 3 The etching solution of Example 1 was heated to 70 ° C. for N, N-.
Dimethylacetamide 90% by weight, potassium hydroxide 1% by weight, diethylene glycol monomethyl ether 9% by weight was used as an etching solution, and the cured epoxy adhesive film was contacted for 15 minutes. As a result, etching was possible. I was able to obtain a wiring board.

Example 4 The etching solution of Example 1 was heated to 50 ° C. to produce N, N-.
Dimethylformamide 80% by weight, sodium hydroxide 4
As a result of using an etching liquid containing 16% by weight of methanol and contacting the cured epoxy adhesive film for 15 minutes, it was possible to perform etching, and a similar multilayer printed wiring board with four layers could be obtained.

Example 5 The etching solution of Example 1 was heated to 60 ° C. for N, N-.
Dimethylformamide 80% by weight, lithium hydroxide 0.
As a result of using an etching solution containing 5% by weight of methanol and 19.5% by weight of methanol and bringing it into contact with a cured epoxy adhesive film for 25 minutes, it was possible to perform etching, and a similar four-layer multilayer printed wiring board could be obtained.

Comparative Example 1 The etching solution of Example 1 was heated to 50 ° C. to obtain N, N-.
As a result of using dimethylacetamide as an etching solution, the cured epoxy adhesive film was not etched and the IVH hole could not be formed.

Comparative Example 2 The etching solution of Example 1 was changed to methanol which was heated to 50 ° C., and as a result, the cured epoxy adhesive film was not etched and IVH holes could not be formed.

Comparative Example 3 The etching solution of Example 1 was changed to an aqueous solution containing 5% by weight of sodium hydroxide and 5% by weight of potassium permanganate at 70 ° C. As a result, the surface of the cured epoxy adhesive film was roughened. However, the inner layer circuit could not be exposed and the hole for IVH could not be formed.

[0034]

EFFECTS OF THE INVENTION According to the present invention, IVH can be collectively formed by chemical etching and small diameter machining of 100 μm or less is possible. Therefore, productivity is greatly improved as compared with conventional drilling. A diameter that is difficult to process is now possible. In addition, because it uses a thermosetting copper-clad adhesive resin sheet and roll lamination and continuous heat curing, it is possible to continuously mold as compared with the conventional prepreg structure and batch method of press, so productivity is dramatically improved. To do. The resin composition used for the thermosetting copper-clad adhesive resin sheet has the same general characteristics as FR-4 grade used for a multilayer printed wiring board. Therefore, it is extremely useful as a method for manufacturing a multilayer printed wiring board used for high-density mounting in various electronic devices.

[Brief description of drawings]

1A to 1M are schematic cross-sectional views in respective steps for explaining an embodiment of the present invention.

2A to 2I are schematic cross-sectional views in each step for explaining a conventional example.

[Explanation of symbols]

1 inner layer circuit board 2 thermosetting copper-clad adhesive resin sheet 3 outer layer copper foil 4 etching resist 5 IVH hole 6 through hole 7 plating 8 etching resist 9 prepreg

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akashi Nakaso 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (8)

[Claims] (1) A bifunctional epoxy resin and a halogenated bifunctional phenol are compounded in such a manner that the compounding equivalent ratio is epoxy group / phenolic hydroxyl group = 1: 0.9 to 1.1, and the A thermosetting epoxy resin composition containing a film-forming epoxy polymer having a molecular weight of 100,000 or more, a cross-linking agent, and a polyfunctional epoxy resin, which are polymerized by heating in the presence of copper, Step of laminating the thermosetting copper-clad adhesive resin sheet formed on the foil to the inner layer board on which a conductor circuit is formed in advance and laminating the resin surface of the thermosetting copper-clad adhesive sheet (2) thermosetting copper-clad adhesive sheet Step of thermosetting the resin layer of the adhesive resin sheet (3) Step of forming etching resist on the outer layer copper foil and forming fine holes on the copper foil surface by selective etching (4) Step of removing etching resist (5 ) A step of etching away the cured resin layer under the fine holes with an etching solution composed of an amide solvent, an alkali metal compound and an alcohol solvent to open a via hole and expose the conductor circuit of the inner layer board (6) Step of plating for electrically connecting the conductor circuit and the outer layer copper foil (7) Step of forming an etching resist on the outer layer copper foil and forming a wiring circuit on the copper foil surface by selective etching (8) Etching A method of manufacturing a multilayer printed wiring board, comprising the step of removing a resist. 2. The amide solvent of the etching solution is N, N-
The dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, or a combination thereof, which is present in the solution at a concentration of 50 to 95% by weight. A method for producing the multilayer printed wiring board described. 3. The alkali metal compound of the etching solution is selected from lithium hydroxide, sodium hydroxide and potassium hydroxide, and is present in the solution at a concentration of 0.5 to 15% by weight. 3. The method for manufacturing a multilayer printed wiring board according to 1 or 2. 4. An alcoholic solvent for an etching solution is methanol, ethanol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether,
Selected from the group consisting of diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether or combinations thereof,
The method for producing a multilayer printed wiring board according to claim 1, wherein the solution is present in the solution at a concentration of 4.5 to 35% by weight. 5. The step of electrically connecting the conductor circuit of the inner layer plate and the outer layer copper foil in the step (5) is a step of applying a conductive paste and drying and curing it to make a connection. A method for manufacturing a multilayer printed wiring board according to claim 1. 6. A method for producing a multilayer printed wiring board having a via hole, wherein (1) a bifunctional epoxy resin and a halogenated bifunctional phenol are mixed in an equivalence ratio of epoxy group / phenolic hydroxyl group = 1: 0. An epoxy polymer having a molecular weight of 100,000 or more and having a film-forming ability, which is compounded so as to be 9 to 1.1 and heated and polymerized in the presence of a catalyst;
A thermosetting epoxy resin composition having a polyfunctional epoxy resin as a constituent component, a thermosetting copper-clad adhesive resin sheet formed on a copper foil, and an thermosetting copper sheet on an inner layer board on which a conductor circuit is formed in advance. Step of laminating and laminating the resin surfaces of the adhesive sheet for adhesive bonding (2) Step of thermosetting the resin layer of the thermosetting copper-adhesive resin sheet (3) Forming an etching resist on the outer layer copper foil and selectively etching the copper foil Step of forming fine holes in the surface (4) Step of removing etching resist (5) Etching and removing the cured resin layer under the fine holes with an etching solution composed of an amide solvent, an alkali metal compound and an alcohol solvent, Step of making a hole and exposing the conductor circuit of the inner layer board (6) Step of plating for electrically connecting the conductor circuit of the inner layer board and the outer layer copper foil (7) On the outer layer copper foil The Tsu quenching resist is formed, the method for manufacturing a multilayer printed wiring board comprising a step of removing the step (8) etching resist to form a wiring circuit on the copper foil surface by selective etching, step (5)
The amide-based solvent of the etching solution used for N, N-dimethylacetamide, N, N-dimethylformamide, N
-Methyl-2-pyrrolidone or an etching solution used in the method for producing a multilayer printed wiring board, which is selected from the group consisting of these and is present in the solution at a concentration of 50 to 95% by weight. 7. The alkali metal compound of the etching solution is selected from lithium hydroxide, sodium hydroxide and potassium hydroxide, and is present in the solution in a concentration of 0.5 to 15% by weight. An etching solution used in the method for producing a multilayer printed wiring board according to item 6. 8. An alcoholic solvent of an etching solution is methanol, ethanol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether,
Selected from the group consisting of diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether or combinations thereof,
The etching solution used in the method for producing a multilayer printed wiring board according to claim 6 or 7, which is present in the solution at a concentration of 4.5 to 35% by weight.