JP2000294932A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a multilayer printed wiring board, in which the so-called 'via fog' is not generated, when an opening for a via hole is formed in an interlayer resin insulating layer and in which a roughened face can be formed easily on the interlayer resin insulating layer. SOLUTION: This manufacturing method for a multilayer printed wiring board includes a process, wherein a substrate 1 on which a conductor circuit is formed is coated with a resin composition for roughened-face formation, containing an organic solvent, the resin composition is dried and an interlayer resin insulating layer 2 if formed, a process in which an opening 6 for a via hole is formed in the interlayer resin insulating layer 2, a process in which the via hole is formed in the opening 6 and in which a conductor circuit is formed on the surface of the interlayer resin-insulating layer 2, a process in which resin composition is formed with a substance which is soluble with respect to a roughening liquid is dispersed into an unhardened heat-resistant resin matrix, which is hardly soluble with respect to the roughening liquid composed of at least one kind selected from among acid, alkali or oxidizing agent, and a process in which the content of the organic solvent prior to the exposure treatment of the interlayer resin insulating layer 2 is set at 5 to 15 wt.%.

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 capable of preventing so-called via fogging when forming a via hole in an interlayer resin insulating layer.

[0002]

2. Description of the Related Art In recent years, a so-called build-up multilayer wiring board has attracted attention due to a demand for higher density of the multilayer wiring board. This build-up multilayer wiring board is manufactured by a method disclosed in, for example, Japanese Patent Publication No. 4-55555. That is, an adhesive for electroless plating made of a photosensitive resin is applied onto the core substrate on which the lower conductive circuit is formed, and then dried and exposed and developed to form an interlayer resin having an opening for a via hole. An insulating layer is formed. Next, after the surface of the interlayer resin insulating layer is roughened by a treatment with an oxidizing agent or the like, the photosensitive resin layer is exposed,
A plating resist is provided by performing a development process, and thereafter, a conductive circuit pattern including via holes is formed by applying electroless plating or the like to a portion where the plating resist is not formed. By repeating such a process a plurality of times, a multilayered build-up wiring board is manufactured.

Conventionally, in such a method of manufacturing a build-up multilayer wiring board, a heat-resistant resin particle soluble in a cured acid or an oxidizing agent is usually used as a photosensitive resin composition applied on the substrate. Alternatively, those that are dispersed in an uncured heat-resistant resin that is hardly soluble in an oxidizing agent are used, and this photosensitive resin is applied, cured, and then treated with a solution of an acid or an oxidizing agent, The heat-resistant resin particles are dissolved and removed, and a roughened surface made of an octopus pot-shaped anchor is formed on the surface of the adhesive layer (interlayer resin insulating layer). Therefore, a conductive circuit having excellent adhesion to the interlayer resin insulating layer can be formed on the interlayer resin insulating layer.

An organic solvent is required in the photosensitive resin composition to uniformly disperse the heat-resistant resin particles and to maintain the viscosity of the resin composition in an appropriate range. At the time of contact drying, about 15 to 20% by weight of the organic solvent was contained. It has been considered that such residual organic solvent is necessary to some extent in order for the resin molecular chains to move during the polymerization reaction.

[0005]

However, when the photosensitive resin composition is applied, dried, and then exposed and developed to form an opening for a via hole, the organic resin in the photosensitive resin composition is reduced. Due to the presence of the solvent, a new problem arises in that the phenomenon that the lower portion of the opening for the via hole is mainly dissolved and removed only in a size smaller than the target size, that is, a so-called via fog occurs.

When such via fogging occurs, if the interlayer resin insulating layer is subsequently subjected to plating, the via holes cause poor connection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. The main object of the present invention is to provide a so-called via fogging when forming an opening for a via hole in an interlayer resin insulating layer. It is another object of the present invention to provide a method of manufacturing a multilayer printed wiring board that can easily form a roughened surface on an interlayer resin insulating layer without using the same.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies for realizing the above-mentioned object, and as a result, have completed the present invention having the following contents. That is, the method for producing a multilayer printed wiring board according to the present invention comprises the steps of (1) applying a resin composition for forming a roughened surface containing an organic solvent onto a substrate on which a conductive circuit is formed, and drying the resin composition to form an interlayer resin insulating layer; Providing step, (2)
Providing a via hole in the interlayer resin insulating layer; and (3) providing a via hole in the via hole opening and forming a conductive circuit on the surface of the interlayer resin insulating layer. A method for manufacturing a wiring board, wherein the resin composition for forming a roughened surface is an uncured heat-resistant resin matrix which is hardly soluble in a roughening liquid comprising at least one selected from an acid, an alkali and an oxidizing agent. A substance which is soluble in a roughening solution comprising at least one selected from an acid, an alkali and an oxidizing agent is dispersed therein, and the interlayer resin insulating layer is dried to the touch before exposure treatment (finger The organic solvent content is 5 to 15% by weight when the organic solvent is dried so that the organic solvent does not deform even when touched.

In the method for producing a multilayer printed wiring board, the substance soluble in a roughening solution comprising at least one selected from the group consisting of an acid, an alkali, and an oxidizing agent includes inorganic particles, resin particles, metal particles, and rubber particles. And at least one selected from liquid phase resins and liquid phase rubbers.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The method for manufacturing a multilayer printed wiring board according to the present invention comprises the steps of (1) applying a resin composition for forming a roughened surface containing an organic solvent onto a substrate on which a conductive circuit is formed, and drying the applied resin composition. Providing an interlayer resin insulation layer, (2) providing a via hole opening in the interlayer resin insulation layer, and (3) providing a via hole in the via hole opening and providing a surface of the interlayer resin insulation layer. A multilayer printed wiring board including a step of forming a conductive circuit, wherein the resin composition for forming a roughened surface comprises a roughening solution comprising at least one selected from an acid, an alkali, and an oxidizing agent. A material which is soluble in a roughening liquid comprising at least one selected from an acid, an alkali and an oxidizing agent in an uncured heat-resistant resin matrix which is hardly soluble, Layer dew The content of the organic solvent during the pre-treatment tack is characterized in that 5 to 15% by weight.

In the method for producing a multilayer printed wiring board according to the present invention, a substance soluble in the roughening solution is dispersed in an uncured heat-resistant resin matrix that is hardly soluble in the roughening solution. Is used as a resin composition for forming a roughened surface (adhesive for electroless plating), so it can be more easily used with various roughening liquids in accordance with the characteristics of the formed interlayer resin insulation layer. A roughened surface having an improved anchor effect can be formed. Further, in the resin composition for forming a roughened surface, the content of the organic solvent at the time of touch drying before the exposure treatment of the interlayer resin insulating layer is adjusted to 5 to 15% by weight. It is possible to prevent the polymerization reaction from proceeding excessively due to excessive movement of the molecular chain. If the polymerization reaction proceeds too much, it hardens to the part that should not be allowed to undergo the curing reaction, and a so-called via fogging (a phenomenon that the interlayer resin under the via hole is not removed but covers the inner layer pad) occurs. In the present invention, via fogging is suppressed by preventing the polymerization reaction from proceeding excessively.
Further, by setting the content of the organic solvent at the time of touch drying before the exposure treatment of the interlayer resin insulating layer to 5% by weight or more,
The movement of the resin molecular chain is prevented from being completely frozen, and the progress of the polymerization reaction is ensured. If the polymerization reaction does not occur, problems such as peeling of the interlayer resin insulating layer during development occur.

Preferably, the content of the organic solvent at the time of touch drying of the interlayer resin insulating layer before the exposure treatment is adjusted to 10 to 12% by weight. 10-1 at 50-60 ° C
This is because the amount of the solvent can be achieved only by heating for 20 minutes.

As the heat-resistant resin matrix, for example, a thermosetting resin or a composite of a thermosetting resin (including one in which a part of the thermosetting group is sensitized) and a thermoplastic resin are used. Can be. As the thermosetting resin,
For example, an epoxy resin, a phenol resin, a polyimide resin, a thermosetting polyolefin resin, and the like can be given. When the thermosetting resin is exposed to light, a methacrylic acid, acrylic acid, or the like is used to cause the thermosetting group to undergo a (meth) acrylation reaction. Particularly, epoxy resin (meth) acrylate is most suitable.

As the epoxy resin, for example, a novolak type epoxy resin, an alicyclic epoxy resin and the like can be used. As the thermoplastic resin, for example, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like can be used. The content of the thermoplastic resin is desirably 30% by weight or less based on the total solid content. 3
By adjusting the amount to 0% by weight or less, the amount of the organic solvent at the time of kneading can be reduced, and the amount of the organic solvent at the time of touch drying can be easily adjusted to 15% by weight or less.

The substance soluble in the roughening liquid comprising at least one selected from the above-mentioned acids, alkalis and oxidizing agents is selected from inorganic particles, resin particles, metal particles, rubber particles, liquid resin and liquid rubber. It is desirable that it is at least one kind.

The inorganic particles include, for example, silica,
Examples include alumina, calcium carbonate, talc, and dolomite. These may be used alone or in combination of two or more. The alumina particles can be dissolved and removed with hydrofluoric acid, and the calcium carbonate can be dissolved and removed with hydrochloric acid. Further, sodium-containing silica and dolomite can be dissolved and removed with an alkaline aqueous solution.

Examples of the resin particles include amino resins (melamine resins, urea resins, guanamine resins, etc.),
Epoxy resins, bismaleimide-triazine resins and the like can be mentioned. These may be used alone or in combination of two or more. The epoxy resin can be arbitrarily manufactured by dissolving in an acid or an oxidizing agent or hardly dissolving in the acid or the oxidizing agent by selecting the type of the oligomer and the curing agent. For example, a resin obtained by curing a bisphenol A-type epoxy resin with an amine-based curing agent is very soluble in chromic acid, but a resin obtained by curing a cresol novolac-type epoxy resin with an imidazole curing agent is not easily dissolved in chromic acid. .

It is necessary that the resin particles have been previously cured. If not cured, the resin particles will dissolve in the solvent that dissolves the resin matrix, so they will be uniformly mixed, and it will not be possible to selectively dissolve and remove only the resin particles with an acid or oxidizing agent. is there.

The metal particles include, for example, gold, silver,
Examples include copper, tin, zinc, stainless steel, and aluminum. These may be used alone or in combination of two or more. Examples of the rubber particles include acrylonitrile-butadiene rubber, polychloroprene rubber,
Polyisoprene rubber, acrylic rubber, polysulfuric rigid rubber,
Fluorine rubber, urethane rubber, silicone rubber, ABS resin and the like can be mentioned. These may be used alone,
Two or more kinds may be used in combination.

As the liquid phase resin, an uncured solution of the thermosetting resin can be used. Specific examples of such a liquid phase resin include, for example, an uncured epoxy oligomer and an amine-based curing agent. And the like. As the liquid phase rubber, for example, an uncured solution of the rubber can be used.

When a resin composition for forming a roughened surface is prepared by using the above liquid phase resin or liquid phase rubber, the heat resistant resin matrix and the soluble substance are not uniformly compatible (that is, the phase is separated. You need to choose these substances, as in By mixing a heat-resistant resin matrix and a soluble substance selected according to the above criteria, a state in which "islands" of liquid-phase resin or liquid-phase rubber are dispersed in the "sea" of the heat-resistant resin matrix Alternatively, a resin composition for forming a roughened surface in which "islands" of a heat-resistant resin matrix are dispersed in the "sea" of a liquid-phase resin or a liquid-phase rubber can be prepared.

After curing the resin composition for forming a roughened surface in such a state, the roughened surface is formed by removing the liquid resin or the liquid rubber in the "sea" or "island". be able to.

The acid constituting the roughening solution includes, for example, phosphoric acid, hydrochloric acid, sulfuric acid, and organic acids such as formic acid and acetic acid. Among them, it is preferable to use an organic acid. This is because when the roughening treatment is performed, the metal conductor layer exposed from the via hole is hardly corroded. As the oxidizing agent, for example, an aqueous solution of chromic acid, an alkaline permanganate (such as potassium permanganate), or the like is desirably used. As the alkali, an aqueous solution of sodium hydroxide, potassium hydroxide or the like is desirable.

The heat-resistant resin matrix of the resin composition for forming a roughened surface desirably contains a (meth) acrylate monomer.

The above (meth) acrylic acid ester monomers include, for example, the following chemical formulas (1), (2),
Compounds represented by (3), (4) and (5) are mentioned.

[0026]

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(Where n is 0 or 1, a and b are 1
Or 2 is represented. )

[0028]

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(In the formula, n represents 0 or 1, and c represents 1 or 2.)

[0030]

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[0031]

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[0032]

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Specific examples of the compounds represented by the chemical formulas (1) and (2) include, for example, KA manufactured by Nippon Kayaku Co., Ltd.
YAMER PM-2, LAYAMAER PM-21
And the like. KAYAMER manufactured by Nippon Kayaku Co., Ltd.
PM-2 contains a methacrylate monomer represented by the following chemical formula (6) as a main component,

[0034]

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This is a mixture containing methacrylic acid ester monomers represented by the following chemical formulas (7) and (8).

[0036]

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[0037]

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LAYAMAER manufactured by Nippon Kayaku Co., Ltd.
PM-21 has a methacrylate monomer represented by the following chemical formula (9) as a main component,

[0039]

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This is a mixture containing methacrylic acid ester monomers represented by the following chemical formulas (10) and (11).

[0041]

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[0042]

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Phosphinic acid or phosphonic acid in such a bifunctional (meth) acrylic acid ester monomer having a P atom improves the adhesion to a metal, and the straight-chain molecules are flexible to the cured product. give.

In the present invention, when the above-mentioned inorganic particles, the above-mentioned metal particles and the above-mentioned resin particles are used, the average particle size is desirably 10 μm or less. Further, in particular, by using a mixture of coarse particles having a relatively large average particle diameter and fine particles having a relatively small average particle diameter having an average particle diameter of less than 2 μm, the electroless plating film Dissolved residues can be eliminated, the amount of palladium catalyst under the plating resist can be reduced, and a shallow and complicated roughened surface can be formed. By forming such a complicated roughened surface, a practical peel strength can be maintained even on a shallow roughened surface.

By combining the above coarse particles and fine particles, a shallow and complicated roughened surface can be formed because the coarse particles used are coarse particles having an average particle size of less than 2 μm. The anchor formed even when dissolved is removed becomes shallow, and the particles to be removed are formed by the mixture of coarse particles having a relatively large particle diameter and fine particles having a relatively small particle diameter. The roughened surface becomes complicated. In this case, the particle diameter used is coarse and the average particle diameter is less than 2 μm, so that roughening does not proceed too much and no voids are generated, and the formed interlayer resin insulating layer has excellent interlayer insulating properties. ing.

When the opening for the via hole is formed by exposure, development processing, laser processing, or the like, the residue of the insulating layer usually remains at the bottom of the opening for the via hole. Since there are components dissolved in the roughening solution such as alkali, acid and oxidizing agent in the layer, such residues can be easily removed by the roughening treatment using the roughening solution.

It is desirable that both the coarse particles and the fine particles are spherical particles, not crushed particles. For crushed particles,
The roughened surface after the roughening treatment is angular, and when the temperature of the interlayer resin insulating layer changes, stress concentration tends to occur at the tip of the angular portion, and therefore, cracks easily occur in the interlayer resin insulating layer due to a heat cycle. Because.

In the present invention, since the anchor to be formed is shallow, both L / S are 40 when either the semi-additive method or the full-additive method is employed.
Fine patterns smaller than / 40 μm can be formed.

Regarding the above particles, the coarse particles have an average particle size of 0.1.
The average particle diameter of the fine particles is more than 8 μm and less than 2.0 μm, and desirably 0.1 to 0.8 μm. In this range, the depth of the roughened surface is approximately Rmax = approximately 3 μm. In the semi-additive method, not only is the electroless plating film easily removed by etching, but also the P under the electroless plating film is reduced.
This is because the d catalyst can be easily removed, and a practical peel strength of 1.0 to 1.3 kg / cm can be maintained.

In addition, the full additive method can not only reduce the amount of Pd catalyst nuclei under the plating resist, but also can prevent the plating resist from remaining, so that even if a shallow anchor is formed, a practical peel strength of 1% can be obtained. .0
１1.3 kg / cm can be maintained.

The mixing weight ratio at this time is desirably from coarse particles / fine particles = 35/10 to 10/10. If the amount of coarse particles is too large, the depth of the anchor becomes too deep to make it difficult to remove the electroless plating film by etching. If the amount of coarse particles is too small, the adhesion strength to the plating film cannot be obtained. The amount of the coarse particles is desirably 10 to 40% by weight based on the solid content of the resin composition for forming a roughened surface. The fine particles are desirably 1 to 15% by weight based on the solid content of the resin composition for forming a roughened surface. Then, the amount of the coarse particles is adjusted so that the weight of the coarse particles is equal to or larger than that of the fine particles in the range of the weight percentage.

The above-described resin composition for forming a roughened surface may be impregnated into a fibrous substrate such as a glass cloth to form a B-stage into a prepreg, or may be formed into a film. Further, it may be formed in the shape of a substrate. Further, the resin composition for forming a roughened surface may be a resin obtained by halogenating a constituent resin to make it flame-retardant.
You may add a pigment and an ultraviolet absorber. Further, a fibrous filler or an inorganic filler may be filled to adjust the toughness and the coefficient of thermal expansion.

The depth of the roughened surface of the interlayer resin insulation layer is R
It is desirable that max = 1 to 5 μm. This roughening depth is equal to the depth of the roughened surface Rmax = 10 formed with the conventional adhesive.
This is about 1/2 of μm, so that even if the electroless plating film under the plating resist is dissolved and removed, no plating residue remains, and the amount of palladium catalyst nuclei under the plating resist can be reduced.

In the semi-additive method, since the conductor circuit is composed of a thin portion of electroless plating and a thick portion of electrolytic plating, the plating stress of electrolytic plating is small, and even if the anchor is shallow, the plating film is peeled off. Hard to do.

In the method for manufacturing a multilayer printed wiring board according to the present invention, a conductive circuit is formed on an interlayer resin insulating layer on a substrate having a lower conductive circuit formed using a resin composition for forming a roughened surface. , Etching,
It is desirable to form a roughened layer by plating or the like.

A roughened surface is formed on the upper surface of the conductor circuit when the above-mentioned multilayer printed wiring board is manufactured by the full additive method, and a roughened surface is formed on the side surface or the entire surface of the conductive circuit when the multilayer printed wiring board is manufactured by the subtractive method. It is desirable. Due to these roughened surfaces, the adhesion between the resin insulating layer and the conductor circuit is improved, and the occurrence of cracks due to the difference in thermal expansion coefficient between the conductor circuit and the resin insulating layer during a heat cycle can be suppressed. It is.

Further, when the roughened layer is formed, the adhesion to the solder resist covering the conductor circuit and the upper interlayer resin insulating layer can be improved, and cracks generated during a heat cycle can be suppressed. be able to.

Next, a method of manufacturing a multilayer printed wiring board according to the present invention will be described by taking a semi-additive as an example. (1) First, a substrate having an inner copper pattern (lower conductive circuit) formed on the surface of a core substrate is prepared. When forming a conductor circuit for this core substrate, a method of etching a copper-clad laminate into a specific pattern, a method of forming an adhesive layer for electroless plating on a substrate such as a glass epoxy substrate, a polyimide substrate, a ceramic substrate, and a metal substrate. Forming, after roughening the surface of the adhesive layer for electroless plating to a roughened surface, a method of performing electroless plating, or performing electroless plating on the entire roughened surface to form a plating resist, Using a method (semi-additive method) of forming a conductor circuit consisting of an electrolytic plating film and an electroless plating film by applying a plating resist after removing the plating resist after applying electrolytic plating to the portion where no plating resist is formed, and performing an etching process. Can be.

Further, a roughened surface or a roughened layer can be formed on the surface of the conductor circuit of the wiring board. Here, the roughened surface or the roughened layer is desirably formed by any one of a polishing process, an etching process, a blackening reduction process, and a plating process. Of these treatments, when performing the blackening reduction treatment, NaOH (20 g
/ L), NaClO ₂ (50 g / l), Na ₃ PO ₄
(Oxidation bath) consisting of an aqueous solution containing (15.0 g / l), NaOH (2.7 g / l), NaBH ₄
A method of forming a roughened surface using a reducing bath composed of an aqueous solution containing (1.0 g / l) is desirable.

When a roughened layer is formed by plating, copper sulfate (1 to 40 g / l), nickel sulfate (0.1 to 6.0 g / l), and citric acid (10 to 20 g / l) are used.
l), sodium hypophosphite (10-100 g / l),
Boric acid (10 to 40 g / l), surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.01 to 10 g / l)
It is preferable to form a roughened layer made of a Cu-Ni-P alloy by performing electroless plating in an electroless plating bath having a pH of 9 and containing l). This is because the crystalline structure of the film deposited in this range has a needle-like structure, and thus has an excellent anchor effect. A complexing agent or an additive may be added to the electroless plating bath in addition to the above compounds.

As the above-mentioned etching method, there is a method in which an etching solution comprising a cupric complex and an organic acid is allowed to act in the presence of oxygen to roughen the surface of the conductor circuit. In this case, the etching proceeds by the chemical reaction of the following equations (12) and (13).

[0062]

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As the cupric complex, a cupric complex of an azole is desirable. This cupric complex of azoles is
It acts as an oxidizing agent that oxidizes metallic copper and the like. Examples of the azoles include diazole, triazole, and tetrazole. Among these, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole and the like are desirable. The content of the cupric complex of azoles in the etching solution is desirably 1 to 15% by weight. This is because it is excellent in solubility and stability, and can also dissolve noble metals such as Pd constituting the catalyst core.

In order to dissolve the copper oxide, an organic acid is added to the azole cupric complex. Specific examples of the organic acid include, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, benzoic acid, Glycolic acid, lactic acid, malic acid, sulfamic acid and the like can be mentioned. These may be used alone or in combination of two or more.

The content of the organic acid in the etching solution is 0.1%.
1 to 30% by weight is desirable. This is because the solubility of the oxidized copper can be maintained and the solubility stability can be ensured. As shown in the above formula (3), the generated cuprous complex dissolves by the action of an acid and combines with oxygen to form a cupric complex, which again contributes to copper oxidation.

To assist in dissolving copper and oxidizing azoles, halogen ions, for example, fluorine ions, chlorine ions, bromine ions, etc., may be added to the above etching solution. Further, halogen ions can be supplied by adding hydrochloric acid, sodium chloride, or the like. The amount of halogen ions in the etching solution is desirably 0.01 to 20% by weight. This is because adhesion between the formed roughened surface and the interlayer resin insulating layer is excellent.

When preparing an etching solution, a cupric complex of an azole and an organic acid (if necessary, having a halogen ion) are dissolved in water. As the etching solution, a commercially available etching solution, for example, “Mech Etch Bond” manufactured by Mec Co., Ltd. is used.
The amount of etching when using the above etching solution is 1 to 1
0 μm is desirable. When the etching amount exceeds 10 μm, poor connection between the formed roughened surface and the via-hole conductor occurs. On the other hand, when the etching amount is less than 1 μm, the adhesion to the interlayer resin insulating layer formed thereon is insufficient. This is because

The roughened layer or roughened surface may be covered with a layer of a metal or a noble metal having a higher ionization tendency than copper and not more than titanium (hereinafter, referred to as a metal layer). Such metals include, for example, titanium, aluminum, zinc, iron, indium, thallium, cobalt, nickel,
Examples include tin, lead, and bismuth. Examples of the noble metal include gold, silver, platinum, and palladium. These may be used alone or in combination of two or more to form a plurality of layers.

These metal layers cover the roughened layer, and even if the interlayer resin insulating layer is roughened, the local electrode reaction is prevented and the conductor circuit is prevented from melting. The thickness of these metals is 0.1-
2 μm is desirable.

Of the metals constituting the metal layer, tin is desirable. This is because tin can form a thin layer by electroless displacement plating and can follow the roughened layer. When forming a metal layer made of tin, a solution containing tin borofluoride-thiourea, or tin chloride-
Displacement plating is performed using a solution containing thiourea. In this case, a Sn layer having a thickness of about 0.1 to 2 μm is formed by the substitution reaction of Cu—Sn. When a metal layer made of a noble metal is formed, a method such as sputtering or vapor deposition can be employed.

Note that a through hole may be formed in the core substrate, and the wiring layer on the front surface and the back surface may be electrically connected via the through hole. In addition, a low-viscosity resin such as a bisphenol F-type epoxy resin may be filled between the through hole and the conductor circuit of the core substrate to ensure smoothness.

(2) Next, on the substrate prepared in the above (1), a resin composition for forming a roughened surface containing an organic solvent is applied and dried to form a layer of the resin composition for forming a roughened surface. Provide. As the roughened surface forming resin composition containing an organic solvent, the above roughened surface forming resin composition having an organic solvent content of 10% by weight or less is used. The resin composition layer for forming a roughened surface may have a plurality of layers, and the particle diameter of each layer may be changed. For example, the lower layer has an average particle size of 1.0 μm, and the upper layer is a mixed particle having an average particle size of 1.0 μm and an average particle size of 0.5 μm, and is composed of a cured product of a resin composition for forming a roughened surface having different particle sizes. You may. The lower layer preferably has an average particle size of 0.1 to 2.0 μm, more preferably an average particle size of 0.1 to 1.0 μm. When applying the resin composition for forming a roughened surface, a roll coater, a curtain coater, or the like can be used.

(3) After the resin composition layer for forming a roughened surface formed in the above (2) is dried to a semi-cured state, an opening for a via hole is provided. In a state where the roughened surface forming resin composition layer is dried, the thickness of the resin composition layer on the conductor circuit pattern is small, and the thickness of the interlayer resin insulation layer on the plane conductor layer having a large area is large. In addition, since irregularities are often generated in the interlayer resin insulating layer due to irregularities of the conductor circuit and the conductor circuit non-formed portion, using a metal plate or a metal roll, pressing while heating, It is desirable to flatten the surface of the resin insulating layer.

The via hole opening is formed by exposing the resin composition layer for forming a roughened surface to ultraviolet rays or the like and then performing a developing treatment. In the case of performing the exposure and development processing, a portion corresponding to the opening for the via hole described above is provided.
A photomask (preferably a glass substrate) on which a black circle pattern is drawn is placed in a state where the side on which the black circle pattern is drawn is in close contact with the resin composition layer for forming a roughened surface.
Develop.

4) Next, the resin composition layer for forming a roughened surface is cured to form an interlayer resin insulating layer, and the interlayer resin insulating layer is roughened. In the roughening treatment, at least one soluble substance selected from inorganic particles, resin particles, metal particles, rubber particles, a liquid-phase resin, and a liquid-phase rubber, which is present on the surface of the interlayer resin insulating layer, is treated with the above-described acid. By using a roughening liquid such as an oxidizing agent or an alkali. The depth of the roughened surface is 1 to 5
About μm is desirable.

(5) Next, a catalyst nucleus is applied to the wiring board having the interlayer resin insulating layer roughened. It is desirable to use a noble metal ion or a noble metal colloid for providing the catalyst nucleus, and generally, palladium chloride or a palladium colloid is used. Note that it is desirable to perform a heat treatment to fix the catalyst core. Palladium is preferred as such a catalyst core.

(6) Next, an electroless plating film is formed on the entire roughened surface. Electroless plating is desirably electroless copper plating. As the plating solution composition, a conventional plating solution can be used. For example, copper sulfate (29 g / l), sodium carbonate (25 g / l), tartrate (140 g / l), sodium hydroxide (40 g / l) ), An aqueous solution containing 37% formaldehyde (150 ml / l) having a pH of 11.5 is desirable. The thickness of the electroless plating film is 0.1 to 5 μm
And more preferably 0.5 to 3 μm.

(7) Next, a photosensitive resin film (dry film) is laminated on the electroless plating film, and a photomask (preferably a glass substrate) on which a plating resist pattern is drawn is brought into close contact with the photosensitive resin film. A plating resist pattern is formed by mounting, exposing, and developing.

(8) Next, electrolytic plating is applied to the portion where the plating resist is not formed to form a conductor circuit and a via hole. Here, it is desirable to use copper plating as the electrolytic plating, and its thickness is desirably 1 to 20 μm.

(9) Further, after the plating resist is removed, the electroless plating film is formed with a mixed solution of sulfuric acid and hydrogen peroxide or an etching solution such as sodium persulfate, ammonium persulfate, ferric chloride and cupric chloride. Dissolve and remove to form an independent conductor circuit. Further, the palladium catalyst nuclei on the exposed roughened surface are dissolved and removed with chromic acid or the like. (10) Next, a roughened layer or a roughened surface is formed on the surface of the conductor circuit. The formation of the roughened layer or the roughened surface is performed by using the method described in the above (1).

(11) Next, an interlayer resin insulating layer is formed on the substrate by using the above-described resin composition for forming a roughened surface by the same method as described above. (12) Next, the steps (3) to (9) are repeated to provide a further upper layer conductive circuit, and a flat conductive pad or via hole functioning as a solder pad is formed thereon, thereby forming a multilayer circuit. Obtain a wiring board. Finally, by forming a solder resist layer and solder bumps, the production of the multilayer printed wiring board is completed. In addition, the following method
Although the method is based on the semi-additive method, a full-additive method may be adopted.

Hereinafter, description will be made based on embodiments.

Example (Example 1) A. Preparation of Resin Composition for Forming Roughened Surface of Upper Layer 1) A 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) is dissolved in diethylene glycol dimethyl ether (DMDG) at a concentration of 80% by weight. Resin solution 400 parts by weight, photosensitive monomer (Aronix M325, manufactured by Toagosei Co., Ltd.) 60
A mixed composition was prepared by placing parts by weight, 5 parts by weight of an antifoaming agent (S-65, manufactured by San Nopco) and 35 parts by weight of N-methylpyrrolidone (NMP) in a container and mixing with stirring.

2) Polyether sulfone (PES) 80
Parts by weight, 72 parts by weight of an epoxy resin particle (manufactured by Sanyo Chemical Co., polymer pole) having an average particle size of 1.0 μm and 31 parts by weight of an epoxy resin particle having an average particle size of 0.5 μm were placed in another container.
After stirring and mixing, 257 parts by weight of NMP were further added,
Another mixed composition was prepared by stirring and mixing with a bead mill.

3) Imidazole curing agent (Shikoku Chemicals, 2
E4MZ-CN) 20 parts by weight, photopolymerization initiator (benzophenone) 4 parts by weight, photosensitizer (manufactured by Ciba-Geigy, EA)
B) 4 parts by weight and 16 parts by weight of NMP were placed in another container and mixed by stirring to prepare a mixed composition. Then, a resin composition for forming a roughened surface was obtained by mixing the mixed compositions prepared in 1), 2) and 3).

B. Preparation of Resin Composition for Forming Lower Surface Roughened Surface 1) Resin solution 400 in which 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) is dissolved in DMDG at a concentration of 80% by weight. Parts by weight, photosensitive monomer (Aronix M3 manufactured by Toa Gosei Co., Ltd.)
25) 60 parts by weight, an antifoaming agent (S-6 manufactured by San Nopco)
5) 5 parts by weight and 35 parts by weight of NMP were placed in a container and mixed by stirring to prepare a mixed composition.

2) Polyether sulfone (PES) 80
Parts, and 145 parts by weight of epoxy resin particles (manufactured by Sanyo Kasei Co., Ltd., polymer pole) having an average particle size of 0.5 μm are placed in another container, mixed with stirring, and further mixed with NMP25.
8 parts by weight were added and mixed by stirring with a bead mill to prepare another mixed composition.

3) Imidazole curing agent (Shikoku Chemicals, 2
E4MZ-CN) 20 parts by weight, photopolymerization initiator (benzophenone) 20 parts by weight, photosensitizer (Ciba-Geigy, E
AB) 4 parts by weight and 16 parts by weight of NMP were placed in another container and mixed by stirring to prepare a mixed composition. Then, an adhesive for electroless plating was obtained by mixing the mixed compositions prepared in 1), 2) and 3).

C. Preparation of resin filler 1) 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., molecular weight: 310, YL983U), the average particle size of which surface is coated with a silane coupling agent is 1.6 μm, and the largest particle Having a diameter of 15 μm or less
iO ₂ spherical particles (CRS 1101- manufactured by Adtech Co., Ltd.)
CE) 170 parts by weight and 1.5 parts by weight of a leveling agent (Perenol S4 manufactured by San Nopco Co.) are placed in a container, and the mixture is stirred and mixed to have a viscosity of 4500 at 23 ± 1 ° C.
A resin filler of 0 to 49000 cps (45 to 49 Pa · s) was prepared. As a curing agent, 6.5 parts by weight of an imidazole curing agent (2E4MZ-CN, manufactured by Shikoku Chemicals Co., Ltd.) was used.

D. Method of manufacturing multilayer printed wiring board (1) Glass epoxy resin or BT having a thickness of 0.6 mm
The starting material was a copper-clad laminate in which 18 μm copper foils 8 were laminated on both sides of a substrate 1 made of (bismaleimide triazine) resin (see FIG. 1A). First, the copper-clad laminate was drilled, subjected to electroless plating, and etched in a pattern to form a lower conductor circuit 4 and through holes 9 on both surfaces of the substrate 1.

(2) Through-hole 9 and lower conductor circuit 4
After the substrate on which was formed was washed with water and dried, NaOH (1
0 g / l), NaClO ₂ (40 g / l), Na ₃ PO
₄ A blackening treatment using an aqueous solution containing (16 g / l) as a blackening bath (oxidizing bath), NaOH (19 g / l), NaB
A reduction treatment was performed using an aqueous solution containing H ₄ (5 g / l) as a reduction bath, and roughened surfaces 4 a and 9 a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 1 (b)). ).

(3) By applying the resin filler 10 to one surface of the substrate using a roll coater, the lower conductor circuit 4
After filling in the space or through hole 9 and heating and drying, the other surface is similarly filled with the resin filler 10 between the conductor circuits 4 or in the through hole 9 and heated and dried (FIG. 1 (c)). )reference).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sander polishing using # 600 belt abrasive paper (manufactured by Sankyo Rikagaku) to form the surface of the inner layer copper pattern 4 and the through holes 9. Polishing was performed so that the resin filler 10 did not remain on the land surface, and then buffing was performed to remove scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, at 100 ° C for 1 hour, at 120 ° C for 3 hours, at 150 ° C
For 1 hour and a heat treatment at 180 ° C. for 7 hours to cure the resin filler 10.

In this way, the surface layer of the resin filler 10 formed in the through-hole 9 and the portion where the conductor circuit is not formed and the surface of the lower conductor circuit 4 are flattened, and the resin filler 10 and the side surface of the lower conductor circuit 4 are flattened. 4a is firmly adhered through the roughened surface, and the inner wall surface 9a of the through hole 9 and the resin filler 10
Was obtained, thereby obtaining an insulating substrate firmly adhered through the roughened surface (see FIG. 1D). By this step, the resin filler 10
And the surface of the lower conductor circuit 4 are flush with each other.

(5) On the land upper surface of the inner layer conductor circuit 4 and the through hole 9 exposed by the processing of the above (4), a thickness of 2.5
Roughened layer (concavo-convex layer) 1 made of μm Cu-Ni-P alloy
1 on the surface of the roughened layer 11.
A 3 μm Sn layer was provided (see FIG. 2A, except that Sn
The layers are not shown). The formation method is as follows. That is, copper sulfate (8 g / l), nickel sulfate (0.6 g / l), citric acid (15 g / l), sodium hypophosphite (29 g / l), boric acid (31 g / l),
Surfactant (Surfinol 46, manufactured by Nissin Chemical Industry Co., Ltd.)
5) The substrate was immersed in an electroless copper plating bath at pH = 9 consisting of an aqueous solution containing (0.1 g / l), and after 1 minute of immersion, vibrated vertically and horizontally at a rate of once every 4 seconds. The surface of the land of the lower conductor circuit and the through hole is
A roughened layer 11 of a needle-like alloy made of -Ni-P was provided. Furthermore, a temperature of 50 ° C. containing tin borofluoride (0.1 mol / l) and thiourea (1.0 mol / l), pH = 1.2
Cu-Sn substitution reaction was performed using the plating bath of No. 1, and a Sn layer having a thickness of 0.3 μm was provided on the surface of the roughened layer.

(6) The resin composition for forming a roughened surface (viscosity: 1.5 Pa · s) described in B was applied to both surfaces of the substrate by a roll coater, and left in a horizontal state for 20 minutes. Drying was performed at 40 ° C. for 40 minutes to form a resin composition layer 2a for forming a roughened surface. Further, on the roughened surface forming resin composition layer 2a, the roughened surface forming resin composition described in A (viscosity: 7 Pa)
・ S) is applied using a roll coater, and 20
After leaving it for 55 minutes, it is dried at 55 ° C. for 40 minutes to form a roughened surface forming resin composition layer 2 b, whereby the total thickness of the roughened surface forming resin composition layer 2 is 35 μm. Was formed (see FIG. 2B). The amount of the residual organic solvent in the interlayer resin insulating layer was measured by heating the substrate at 150 ° C. for 5 hours and changing the weight. As a result, it was found that the content was 10% by weight.

(7) A photomask film on which a black circle having a diameter of 85 μm is printed is brought into close contact with both surfaces of the substrate 1 on which the resin composition layer 2 for forming a roughened surface has been formed in the above (6), and is brought into contact with an ultrahigh pressure mercury lamp. After exposure at 500 mJ / cm ² intensity, DMD
Spray developed with G solution. Thereafter, the substrate is further exposed to an ultrahigh pressure mercury lamp at an intensity of 3000 mJ / cm ² , and subjected to a heat treatment at 100 ° C. for 1 hour and at 150 ° C. for 5 hours to obtain a diameter excellent in dimensional accuracy equivalent to a photomask film. Thickness 3 having 85 μm via hole opening 6
An interlayer resin insulation layer 2 having a thickness of 5 μm was formed (see FIG. 2C). Note that the tin plating layer was partially exposed in the opening serving as the via hole.

(8) The substrate having the via hole opening 6 formed thereon was placed in a solution containing 800 g / l chromic acid at 70 ° C. for 19 hours.
The surface of the interlayer resin insulation layer 2 is roughened (depth: 3 μm) by dissolving and removing the epoxy resin particles present on the surface of the interlayer resin insulation layer 2, and then neutralizing solution (manufactured by Shipley Co., Ltd.) ) And washed with water (Fig. 2)
(D)). Further, by applying a palladium catalyst (manufactured by Atotech) to the surface of the substrate subjected to the surface roughening treatment, catalyst nuclei were attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6.

(9) Next, the substrate was immersed in an aqueous electroless copper plating solution having the following composition to form an electroless copper plating film 12 having a thickness of 0.8 μm on the entire rough surface (FIG. 3 (a)). )reference).
At this time, since the plating film was thin, irregularities were observed on the surface of the electroless plating film. [Electroless plating aqueous solution] EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l Polyethylene glycol (PEG) 0.1 g / l Electroplating conditions] 30 minutes at a liquid temperature of 70 ° C

(10) A commercially available photosensitive dry film is adhered to the electroless copper plating film 12, and a mask is placed thereon.
Exposure at mJ / cm ² and development with a 0.8% aqueous sodium carbonate solution provided a plating resist 3 (see FIG. 3B).

(11) Then, the substrate was washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions to a thickness of 15 μm. (See FIG. 3C). [Electrolytic plating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive 1 ml / l (Capparaside GL, manufactured by Atotech Japan) [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(12) After the plating resist 3 is peeled and removed with 5% KOH, the electroless plating film 12 under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and the electroless plating film is removed. Copper plating film 12 and electrolytic copper plating film 1
A conductor circuit (including the via hole 7) 5 made of 3 and having a thickness of 18 μm was formed. Further, the surface of the interlayer resin insulating layer 2 between the conductor circuits located at the part where the conductor circuits are not formed is immersed in a 70 ° C. solution containing 800 g / l of chromic acid for 3 minutes, and the surface of the interlayer resin insulation layer 2 is etched by 1 μm. The resulting palladium catalyst was removed (see FIG. 3 (d)).

(13) The substrate on which the conductor circuit 5 was formed was coated with copper sulfate (8 g / l), nickel sulfate (0.6 g / l), citric acid (15 g / l), and sodium hypophosphite (29 g / l).
l), an aqueous solution containing boric acid (31 g / l) and a surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.1 g / l). After immersion, one minute after immersion, vibrating in the vertical and horizontal directions at a rate of once every 4 seconds, the surface of the land of the lower conductor circuit and the through-hole was roughened with a needle-like alloy made of Cu-Ni-P. An oxide layer 11 was provided (see FIG. 4A). At this time, the formed roughened layer 11 is converted to an EPMA (X-ray fluorescence analyzer).
As a result, the composition ratio of Cu was 98 mol%, Ni was 1.5 mol%, and P was 0.5 mol%. Further, tin borofluoride (0.1 mol / l), thiourea (1.0 mol / l)
(mol / l) using a plating bath at a temperature of 50 ° C. and a pH of 1.2, and a Cu—Sn substitution reaction was performed to provide a 0.3 μm thick Sn layer on the surface of the roughened layer. However, the Sn layer is not shown.

(14) By repeating the above steps (6) to (13), a further upper layer conductive circuit was formed, and a multilayer wiring board was obtained. However, Sn substitution was not performed (see FIGS. 4B to 5B).

(15) Next, a sensitizing oligomer in which 50% of epoxy groups of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) is acrylated and dissolved in DMDG to a concentration of 60% by weight. (Molecular weight: 4000) 4
6.67 parts by weight of 80 dissolved in methyl ethyl ketone
6.67 parts by weight of bisphenol A type epoxy resin (manufactured by Yuka Shell Co., trade name: Epicoat 1001) by weight
Similarly, bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name: Epicoat E-1001-B80) 6.6
7 parts by weight, 1.6 parts by weight of an imidazole curing agent (trade name: 2E4MZ-CN, manufactured by Shikoku Chemicals Co., Ltd.), and 4.5 of a bifunctional acrylic monomer which is a photosensitive monomer (trade name: R604, manufactured by Nippon Kayaku Co., Ltd.) 1.5 parts by weight of a polyvalent acrylic monomer (manufactured by Kyoei Chemical Co., Ltd., trade name: DPE6A), and a leveling agent composed of an acrylate polymer (manufactured by Kyoei Chemical Co., trade name: Polyflow No. 75)
36 parts by weight were placed in a container, stirred and mixed to prepare a mixed composition, and 2.0 parts by weight of Irgacure I-907 (manufactured by Ciba Geigy) as a photopolymerization initiator, and a photosensitizer as a photopolymerization initiator. DETX-S (manufactured by Nippon Kayaku Co., Ltd.)
By adding 0.2 parts by weight and 0.6 parts by weight of DMDG, a solder resist composition having a viscosity adjusted to 1.4 ± 0.3 Pa · s at 25 ° C. was obtained. The viscosity was measured by
60 rpm with a type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.)
In the case of the rotor No. In the case of 4, 6 rpm, the rotor No. According to 3.

(16) Next, the above-mentioned solder resist composition is applied to both sides of the multilayer wiring board in a thickness of 20 μm,
After performing a drying process under the conditions of 20 ° C. for 20 minutes and 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the opening of the solder resist is drawn is brought into close contact with the solder resist layer, and an ultraviolet ray of 1000 mJ / cm ² is applied. Exposure with DM
Development was performed with a TG solution to form an opening having a diameter of 200 μm. Then, at 80 ° C. for 1 hour, and at 100 ° C. for 1 hour.
The solder resist layer was cured by performing heat treatment under the conditions of 120 ° C. for 1 hour and 150 ° C. for 3 hours to form a solder resist pattern layer 14 having an opening and a thickness of 20 μm.

(17) Next, the substrate on which the solder resist layer 14 was formed was replaced with nickel chloride (30 g / l), sodium hypophosphite (10 g / l), and sodium citrate (10 g / l).
g / l) in the electroless nickel plating solution with pH = 5.
This was immersed for 0 minutes to form a nickel plating layer 15 having a thickness of 5 μm in the opening. Further, the substrate was subjected to potassium gold cyanide (2 g / l), ammonium chloride (75 g / l),
It was immersed in an electroless plating solution containing sodium citrate (50 g / l) and sodium hypophosphite (10 g / l) at a temperature of 93 ° C. for 23 seconds to form a 0.03 μm thick nickel plating layer 15 on the nickel plating layer 15. A gold plating layer 16 was formed.

(18) Thereafter, a solder paste is printed in the openings of the solder resist layer 14 and reflowed at 200 ° C. to form solder bumps (solder bodies) 17.
A multilayer wiring printed board having the solder bumps 17 was manufactured (see FIG. 5C).

(Example 2) A resin composition layer for forming a roughened surface was formed using a resin composition for forming a roughened surface having the following component composition, and then cured to form an interlayer resin insulating layer. Except for this, a multilayer printed wiring board having solder bumps was manufactured in the same manner as in Example 1. 46.67 weight of a photosensitizing oligomer (molecular weight: 4000) in which 50% of an epoxy group of a cresol novolak type epoxy resin (manufactured by Nippon Kayaku) is dissolved in DMDG so as to have a concentration of 80% by weight. Part, bisphenol A type epoxy resin (manufactured by Yuka Shell Co., trade name: Epicoat 100) dissolved in methyl ethyl ketone at 80% by weight
1) 6.67 parts by weight, also bisphenol A type epoxy resin (trade name: Epicoat E-10, manufactured by Yuka Shell Co., Ltd.)
01-B80) 6.67 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals Co., Ltd., trade name: 2E4MZ-CN) 1.6 parts by weight, bifunctional acrylic monomer which is a photosensitive monomer (trade name, manufactured by Nippon Kayaku Co., Ltd.) : R604) 4.5 parts by weight, similarly polyvalent acrylic monomer (manufactured by Kyoei Chemical Co., trade name: D
PE6A) 1.5 parts by weight, terminal epoxy-modified butadiene rubber (Denalax R-45E, manufactured by Nagase Chemical Industry Co., Ltd.)
P) 12 parts by weight of a leveling agent composed of an acrylate polymer (manufactured by Kyoei Chemical Co., Ltd., trade name: Polyflow No.
75) 0.36 parts by weight is placed in a container, stirred and mixed to prepare a mixed composition, and Irgacure I-907 (manufactured by Ciba Geigy) is used as a photopolymerization initiator for the mixed composition.
By adding 2.0 parts by weight, 0.2 parts by weight of DETX-S (produced by Nippon Kayaku Co., Ltd.) as a photosensitizer, and 5.6 parts by weight of DMDG, the viscosity at 25 ° C. is 7 ± 0.1 Pa · s. Was adjusted. Drying conditions for the touch were 55 ° C. for 35 minutes. The amount of the organic solvent in the interlayer resin insulating layer was 12% by weight. The roughening treatment used an aqueous 0.1 mol / l potassium permanganate solution of alkali (NaOH).

(Comparative Example 1) A multilayer printed wiring board was obtained in the same manner as in Example 1, except that the touch drying temperature was changed to 55 ° C for 10 minutes in (6). The amount of the organic solvent in the interlayer resin insulating layer was 18% by weight.

(Comparative Example 2) A multilayer printed wiring board was obtained in the same manner as in Example 1, except that the touch drying temperature was changed to 55 ° C for 80 minutes in (6). The amount of the organic solvent in the interlayer resin insulating layer was 3% by weight.

The multilayer printed wiring boards of Examples 1 and 2 and Comparative Examples 1 and 2 manufactured as described above were cut vertically so as to include the via hole openings, and the shapes of the via hole openings and the interlayer resin were determined. The presence or absence of peeling of the insulating layer from the conductor circuit was observed with a microscope. The results are shown in Table 1 below.

[0112]

[Table 1]

As is clear from the results shown in Table 1 above,
In the multilayer printed wiring boards of Examples 1 and 2 manufactured by the method for manufacturing a multilayer printed wiring board of the present invention, no via fogging occurred in the via hole openings formed in the interlayer resin insulating layer. In the multilayer printed wiring board of Comparative Example 1, via fogging occurred in the formed via hole opening, whereas in the multilayer printed wiring board of Comparative Example 2, Since the curing reaction did not proceed, peeling occurred between the interlayer resin insulating layer and the conductor circuit during development.

[0114]

As described above, according to the method for manufacturing a multilayer printed wiring board of the present invention, when an opening for a via hole is formed in an interlayer resin insulating layer, so-called via fogging does not occur. The adhesion of the insulating layer to the conductor circuit is not reduced.

[Brief description of the drawings]

FIGS. 1A to 1D are cross-sectional views showing a part of a manufacturing process of a multilayer printed wiring board according to the present invention.

FIGS. 2A to 2D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 3A to 3D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 4A to 4C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 5A to 5C are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 interlayer resin insulating layer (roughened surface forming resin composition layer) 2a roughened surface forming resin composition layer 2b roughened surface forming resin composition layer 3 plating resist 4 lower conductor circuit (inner copper pattern) 5 Upper Conductor Circuit 6 Via Hole Opening 7 Via Hole 8 Copper Foil 9 Through Hole 10 Filling Resin (Resin Filler) 11 Roughening Layer 12 Electroless Plating Film 13 Electrolytic Plating Film 14 Solder Resist Layer 15 Nickel Plating Layer 16 Gold Plating Layer 17 Solder bump

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoko Nishiwaki 1-1, Ibigawa-cho, Ibi-gun, Gifu Prefecture F-term (reference) 5E346 AA12 AA15 AA32 AA43 BB01 CC08 CC09 CC10 CC13 CC16 CC31 CC33 CC58 DD02 DD22 DD32 DD47 EE31 EE38 FF02 FF04 FF07 FF15 GG15 GG19 GG27 HH07 HH11

Claims (2)

[Claims] (1) a step of applying a resin composition for forming a roughened surface containing an organic solvent on a substrate on which a conductive circuit is formed and drying to provide an interlayer resin insulating layer; Providing a via hole opening in the insulating layer, and (3) providing a via hole in the via hole opening,
A method for manufacturing a multilayer printed wiring board including a step of forming a conductive circuit on a surface of the interlayer resin insulating layer, wherein the resin composition for forming a roughened surface is at least one selected from an acid, an alkali, and an oxidizing agent. An uncured heat-resistant resin matrix which is hardly soluble in a roughening liquid comprising a substance which is soluble in a roughening liquid comprising at least one selected from an acid, an alkali and an oxidizing agent. And
The method for producing a multilayer printed wiring board, wherein the content of the organic solvent before the exposure treatment of the interlayer resin insulating layer is 5 to 15% by weight. 2. The substance soluble in a roughening liquid comprising at least one selected from the group consisting of an acid, an alkali and an oxidizing agent includes inorganic particles, resin particles, metal particles, rubber particles, liquid resin and liquid rubber. The method for producing a multilayer printed wiring board according to claim 1, wherein the method is at least one selected from the group consisting of: