JP2002134920A - Multilayer printed wiring board and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer printed wiring board wherein cracks are not generated in a resin filler layer and peeling is not generated between the resin filler layer and a conductor layer under heat cycle condition, coping with high speed of an IC chip is obtained and connection reliability is superior. SOLUTION: In this multilayer printed wiring board, conductor circuits and interlayer resin insulating layers are laminated in order on both surfaces of a substrate, and parts between the conductor circuits are connected via through holes and viaholes. In the through hole, the resin filler layer wherein resin filler containing epoxy resin, hardener and inorganic particles is cured is formed. The content of the inorganic particles in the resin filler layer is 10-50 wt.%. On the through hole, the conductor layer covering the surface layer part of the resin filler layer is formed as a part of the conductor circuit, and the viahole is formed on the conductor layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer printed wiring board and a method for manufacturing the multilayer printed wiring board.

[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, for example,
It is manufactured by a method as disclosed in Japanese Patent Publication No. 55555/1992. 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 and developed to provide a plating resist, and then,
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.

In such a method of manufacturing a build-up wiring board, when a through hole is formed in a core board,
By simply forming a through hole in the core substrate and forming a conductor layer on the wall surface of the through hole, a void is formed in the through hole. When the lamination process of the interlayer resin insulating layer is performed while having such a gap, the adhesive for electroless plating flows into the gap when the adhesive for electroless plating is applied, and as a result, the electroless plating is performed. Depressions (dents) and undulations are generated in the layer made of the plating adhesive. The occurrence of such a concave portion or the like causes a connection failure, and has a problem that the reliability of the build-up wiring board is reduced.

[0004] As a technique for solving such a problem, for example, Japanese Patent Application Laid-Open No. 63-137499 discloses a method in which the inside of a void is filled with an epoxy resin paste.

[0005] However, in the multilayer printed wiring board manufactured by this method, although no depressed portion or undulation is generated in the interlayer resin insulating layer, cracks are generated in the resin filler layer under heat cycle conditions, Peeling sometimes occurred between the filler layer and the conductor layer. This is because, due to the difference in thermal expansion coefficient between the resin filler layer and the substrate, stress is generated in the multilayer printed wiring board, and the resin filler layer is not configured to relieve the stress, It is considered that peeling and cracks occurred.

In order to solve the above-mentioned problems, the applicant of the present invention disclosed in Japanese Patent Application Laid-Open No. Hei 10-200265 a resin filler containing a bisphenol F type epoxy resin and inorganic particles such as silica. A multi-layer printed wiring board filled in a hole is disclosed. In such a multilayer printed wiring board, since the resin filler layer contains inorganic particles, the stress generated under heat cycle conditions can be reduced, and cracks occur in the resin filler layer, Separation does not easily occur between the material layer and the conductor layer.

However, the multilayer printed wiring board disclosed herein has a configuration in which conductor circuits sandwiching only the substrate are electrically connected via through holes, and the substrate and the interlayer resin insulation layer are connected to each other. No mention is made of a multilayer printed wiring board having a configuration in which conductive circuits sandwiched therebetween are electrically connected via through holes, and the thermal expansion coefficient and the like of both are not particularly considered.

Japanese Patent Application Laid-Open No. 2000-165046 discloses that a via hole is formed immediately above a through hole,
A multilayer printed wiring board has been disclosed which can reduce the wiring length in the multilayer printed wiring board and shorten the signal transmission time, thereby responding to an increase in the speed of an IC chip. In such a multilayer printed wiring board, a resin filler containing inorganic particles is filled in the through hole, a conductor layer covering the resin filler layer is formed on the through hole, and a via hole is formed on the conductor layer. Have been.

However, in the multilayer printed wiring board disclosed herein, there is no mention of the adhesion between the resin filler layer and the conductor layer covering the resin filler layer, and the resin is not heat-cycled. Separation sometimes occurred between the filler layer and the conductor layer.

[0010]

Therefore, the inventors of the present invention have proposed a method in which conductor circuits sandwiching a substrate and an interlayer resin insulation layer are connected by through holes, and via holes are formed on the through holes. In a multilayer printed wiring board having a configuration, even under heat cycle conditions, cracks do not occur in the resin filler layer, and a multilayer printed wiring board in which peeling does not occur between the resin filler layer and the conductor layer is studied. As a result, they found that the above-mentioned required properties were satisfied if the content ratio of the inorganic particles in the resin filler layer obtained by curing the resin filler containing the epoxy resin, the curing agent, and the inorganic particles was 10 to 50% by weight. Thus, the present invention has been completed.

[0011]

That is, in the multilayer printed wiring board of the present invention, a conductor circuit and an interlayer resin insulation layer are sequentially laminated on both surfaces of a substrate, and the conductor circuit sandwiching the substrate and the interlayer resin insulation layer therebetween. Are connected through through holes,
A multilayer printed wiring board in which conductor circuits sandwiching the interlayer resin insulating layer are connected via via holes,
In the through hole, a resin filler layer obtained by curing a resin filler containing an epoxy resin, a curing agent, and inorganic particles is formed, and a content ratio of the inorganic particles in the resin filler layer is: A conductor layer covering the surface layer of the resin filler layer is formed as a part of a conductor circuit on the through hole, and a via hole is formed on the conductor layer. It is characterized by being.

Preferably, the inorganic particles are made of at least one selected from the group consisting of aluminum compounds, calcium compounds, potassium compounds, magnesium compounds and silicon compounds.

The shape of the inorganic particles is desirably spherical, elliptical, crushed, or polyhedral.

In the above-mentioned multilayer printed wiring board,
It is desirable that a roughened surface is formed on at least a part of the surface of the conductor layer forming the through hole.

The method for manufacturing a multilayer printed wiring board according to the present invention is characterized by including at least the following steps (A) to (I). (A) a through-hole forming step of forming a through-hole in a substrate having a lower conductor circuit and a lower interlayer resin insulating layer formed on both surfaces thereof; and (B) a wall surface of the through-hole and the lower interlayer resin insulating layer. A conductor layer forming step of forming a conductor layer on a part of the surface,
(C) An epoxy resin, a curing agent, and inorganic particles are contained in the through-hole having the conductor layer formed on the wall surface thereof, and the content of the inorganic particles after curing is 10 to 50% by weight. A resin filling step of filling the resin composition, (D) a drying step of drying the resin composition for filling the through hole, and (E) a polishing treatment on the surface of the resin composition for filling the through hole exposed from the through hole. (F) a through-hole forming step of curing the resin composition for filling a through-hole and forming a through-hole having a resin filler layer formed therein;
(G) a cover plating layer forming step of forming a conductor layer covering a surface portion of the resin filler layer as a part of a conductor circuit; (H) a via on a lower interlayer resin insulation layer having a conductor layer formed on its surface; An upper interlayer resin insulating layer forming step of laminating and forming an upper interlayer resin insulating layer having a hole opening; and (I) a via hole forming step of forming a conductor layer in the via hole opening.

In the method for manufacturing a multilayer printed wiring board, the polishing step is preferably a step of performing at least one buff polishing process.

In the conductor layer forming step, it is preferable that a roughened surface is formed on at least a part of the surface of the conductor layer after forming the conductor layer.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The multilayer printed wiring board of the present invention
A conductor circuit and an interlayer resin insulation layer are sequentially laminated on both sides of a substrate, and the conductor circuit sandwiching the substrate and the interlayer resin insulation layer is connected through a through hole, and a conductor circuit sandwiching the interlayer resin insulation layer is provided. A multilayer printed wiring board in which the layers are connected via via holes, and a resin filler layer formed by curing a resin filler containing an epoxy resin, a curing agent, and inorganic particles is formed in the through hole. Has been
The content ratio of the inorganic particles in the resin filler layer is 10
A conductor layer covering the surface layer of the resin filler layer is formed as a part of a conductor circuit on the through hole, and a via hole is formed on the conductor layer. It is characterized by the following.

In the multilayer printed wiring board, since the resin filler layer containing 10 to 50% by weight of inorganic particles is formed in the through-hole, the resin filler layer and the interlayer resin insulating layer or the substrate are interposed. There is no significant difference in the coefficient of thermal expansion.
Since the resin filler layer and the conductor layer covering the surface layer thereof have excellent adhesion, cracks may occur in the resin filler layer even under heat cycle conditions, and the resin filler layer and the conductor layer may be interposed between the resin filler layer and the conductor layer. No peeling occurs and excellent connection reliability.

On the through hole of the multilayer printed wiring board, a conductor layer covering a surface portion of the resin filler layer is formed as a part of a conductor circuit, and a via hole is formed on the conductor layer. Therefore, since the wiring length in the multilayer printed wiring board is short and the signal transmission time is short, it is possible to cope with an increase in the speed of an IC chip.

In the multilayer printed wiring board of the present invention, a resin filler layer obtained by curing a resin filler containing an epoxy resin, a curing agent and inorganic particles is formed in a through hole. The epoxy resin is not particularly limited, but is preferably at least one selected from the group consisting of a bisphenol epoxy resin and a novolak epoxy resin. The viscosity of bisphenol-type epoxy resin can be adjusted without using a diluting solvent by selecting A-type or F-type resin. Novolak-type epoxy resin has high strength, heat resistance and chemical resistance. This is because they are excellent in properties, do not decompose even in a strongly basic solution such as an electroless plating solution, and are hardly thermally decomposed.

The bisphenol type epoxy resin is preferably a bisphenol A type epoxy resin or a bisphenol F type epoxy resin, and more preferably a bisphenol F type epoxy resin because it has a low viscosity and can be used without a solvent. As the novolak epoxy resin, at least one selected from a phenol novolak epoxy resin and a cresol novolak epoxy resin is desirable.

Further, a bisphenol type epoxy resin and a cresol novolak type epoxy resin may be mixed and used. In this case, the mixing ratio of the bisphenol epoxy resin and the cresol novolac epoxy resin is
It is desirable that the weight ratio be 1/1 to 1/100. By mixing in this range, an increase in viscosity can be suppressed.

The curing agent contained in the resin filler is not particularly limited, and a conventionally known curing agent can be used.
An imidazole hardener, an acid anhydride hardener, or an amine hardener is desirable. This is because when these curing agents are used, the degree of shrinkage during curing is small, and the adhesion between the conductor layer or the like constituting the through hole and the resin filler layer is particularly excellent.

The inorganic particles contained in the resin filler include, for example, those composed of aluminum compounds, calcium compounds, potassium compounds, magnesium compounds, silicon compounds and the like. These may be used alone or in combination of two or more.

The aluminum compound includes, for example, alumina and aluminum hydroxide. The calcium compound includes, for example, calcium carbonate,
Calcium hydroxide and the like, as the potassium compound, for example, potassium carbonate and the like, as the magnesium compound, for example, magnesia, dolomite, basic magnesium carbonate, talc and the like,
Examples of the silicon compound include silica and zeolite.

The content ratio of the inorganic particles in the resin filler is 10 to 50% by weight. Within this range,
This is because the thermal expansion coefficient can be matched between the substrate and the interlayer resin insulating layer. When the content ratio of the inorganic particles is less than 10% by weight, it is difficult to match the thermal expansion coefficient with a substrate containing an inorganic component such as glass fiber,
On the other hand, when the content ratio of the inorganic particles exceeds 50% by weight, it is difficult to match the thermal expansion coefficient with the interlayer resin insulating layer having a low content of the inorganic particles. A more desirable content ratio is 20 to 40% by weight.

The shape of the inorganic particles is not particularly limited, and may be spherical, elliptical, crushed, polyhedral, and the like. Among these, a spherical shape and an elliptical spherical shape are desirable. This is because generation of cracks due to the shape of the particles can be suppressed. Further, the inorganic particles may be coated with a silane coupling agent or the like. This is because the adhesion between the inorganic particles and the epoxy resin is improved.

It is preferable that a roughened surface is formed on at least a part of the surface of the conductor layer forming the through hole. This is because the adhesion between the conductor layer and the resin filler layer is further enhanced, and expansion and shrinkage upon receiving a heat history can be suppressed, and peeling or the like between the two layers is less likely to occur.

The average roughness of the roughened surface is 0.05 to 5 μm.
m is desirable. The average roughness is 0.05 μm
If less than 5 μm, the effect of roughening the surface of the conductor circuit can hardly be obtained. On the other hand, if it exceeds 5 μm, signal delay or signal error may occur due to the skin effect during signal transmission. Because there is.

The resin filler may contain other thermosetting resins, thermoplastic resins, and the like, in addition to the above-mentioned epoxy resin and the like. Examples of the thermosetting resin include polyimide resin and phenol resin. Examples of the thermoplastic resin include polytetrafluoroethylene (PTFE) and tetrafluoroethylene hexafluoropropylene copolymer (FEP). ) Fluororesins such as tetrafluoroethylene perfluoroalkoxy copolymer (PFA), polyethylene terephthalate (PET), polysulfone (PSF), polyphenylene sulfide (PPS), thermoplastic polyphenylene ether (PPE), polyether sulfone (PES), polyetherimide (PE
I), polyphenylene sulfone (PPES), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyolefin-based resin and the like. These may be used alone or in combination of two or more. These resins may be used instead of the epoxy resin.

In the above-mentioned multilayer printed wiring board,
On the through hole, a conductor layer (hereinafter, also referred to as a cover plating layer) that covers a surface portion of the resin filler layer is formed as a part of a conductor circuit, and a via hole is formed on the conductor layer. I have. Since the resin filler layer contains the inorganic particles in the above range, the resin filler layer has excellent adhesion to the conductor layer covering the same. This will be described in detail when describing the method for manufacturing a multilayer printed wiring board of the present invention.

Further, by forming the lid plating layer and forming a via hole on the lid plating layer, the through hole and the via hole become linear, and the wiring length is shortened. The length can be shortened, and the speed of the IC chip can be increased. In addition, since the lid plating layer is a part of the conductor circuit and via holes can be formed on the lid plating layer, a multilayer printed wiring board having a higher wiring density can be obtained.

In the multilayer printed wiring board according to the present invention, a conductor circuit and an interlayer resin insulation layer are sequentially laminated on both sides of the board, and the through hole having the above-described structure allows the conductor circuit and the interlayer resin insulation layer to be sandwiched between the board and the interlayer resin insulation layer. Are electrically connected. That is, a total of four conductor circuits including the two-layer conductor circuit and the two-layer conductor circuits formed on both sides of the substrate as well as between the two-layer conductor circuits sandwiching the substrate and the interlayer resin insulating layer. The spaces are electrically connected by through holes. As the substrate, a resin substrate is desirable, and specific examples include, for example, a glass epoxy substrate, a polyester substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a thermosetting polyphenylene ether substrate, a fluororesin substrate, and FR.
-4 substrate, FR-5 substrate and the like. Further, a copper-clad laminate or an RCC substrate may be used.

The material of the conductor circuit is not particularly limited, and includes, for example, tin, zinc, copper, nickel, cobalt, thallium, lead and the like. Further, the conductor circuit may be formed of a single layer, or may be formed of two or more layers. Among these, those made of copper, copper, and nickel are desirable in consideration of electrical characteristics, economy, and the like.

The conductor circuit may have a roughened surface. If the surface of the conductor circuit is a roughened surface,
This is because the adhesion between the conductor circuit and the interlayer resin insulating layer becomes stronger. The average roughness of the roughened surface is
It is desirable that the thickness be 0.05 to 5 μm. If the above roughness is less than 0.05 μm, the effect of roughening the surface of the conductor circuit can hardly be obtained, while if it exceeds 5 μm, signal delay and This is because a signal error may occur.

In such a conductor circuit, between the conductor circuits sandwiching the interlayer resin insulation layer, the above-described through hole,
They are electrically connected by via holes. The material of the via hole is desirably the same as the material of the conductor circuit. Further, the via hole may have a field via structure. A via hole having a field via structure is suitable for providing a via hole above the via hole. When a via hole is formed on a via hole, the signal transmission time can be reduced, as in the case of forming a via hole on a through hole.
It is possible to cope with an increase in the speed of an IC chip.

Examples of the material of the interlayer resin insulating layer include thermosetting resins, thermoplastic resins, and composites thereof. Specific examples of the thermosetting resin, for example, epoxy resin, phenolic resin, polyimide resin,
Examples thereof include a polyester resin, a bismaleimide resin, a polyolefin resin, and a polyphenylene ether resin.

Examples of the epoxy resin include cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, alkylphenol novolak type epoxy resin, biphenol F type epoxy resin, and naphthalene type epoxy resin. Resin, dicyclopentadiene type epoxy resin, epoxidized product of condensate of phenols and aromatic aldehyde having phenolic hydroxyl group,
Triglycidyl isocyanurate, alicyclic epoxy resin and the like. These may be used alone or in combination of two or more. Thereby, it becomes excellent in heat resistance and the like.

Examples of the polyolefin-based resin include polyethylene, polystyrene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, cycloolefin-based resins, and copolymers of these resins.

As a commercially available product of the above-mentioned polyolefin resin, for example, a product name of Sumitomo 3M Ltd .: 15
92 and the like. Further, a thermoplastic polyolefin resin having a melting point of 200 ° C. or more can be used. Specific commercial products include, for example, trade names: TPX (melting point 240 ° C.) manufactured by Mitsui Petrochemical Industries, Ltd., and Idemitsu Petrochemical Co., Ltd. Trade name: SPS (melting point: 270 ° C.). Among them, cyclo-dielectric materials have low dielectric constant and dielectric loss tangent, are unlikely to cause signal delay and signal error even when a high-frequency signal in the GHz band is used, and are excellent in mechanical characteristics such as rigidity. Olefin resins are desirable.

As the above cycloolefin resin, 2
Homopolymers or copolymers of monomers comprising -norbornene, 5-ethylidene-2-norbornene or derivatives thereof are desirable. As the above derivative, the above 2-
Examples include those in which an amino group for forming a crosslink, a maleic anhydride residue, or a maleic acid-modified one is bonded to a cycloolefin such as norbornene. Examples of monomers for synthesizing the copolymer include ethylene and propylene.

The above cycloolefin resin may be a mixture of two or more of the above resins, or may contain a resin other than the cycloolefin resin. When the cycloolefin resin is a copolymer, it may be a block copolymer or a random copolymer.

The cycloolefin resin is preferably a thermosetting cycloolefin resin.
This is because by performing the heating to form the crosslinks, the rigidity is further increased and the mechanical properties are improved. The glass transition temperature (Tg) of the cycloolefin resin is 13
Desirably, the temperature is 0 to 200 ° C.

As the cycloolefin-based resin, those already formed as a resin sheet (film) may be used, and a monomer or a low-molecular-weight polymer having a certain molecular weight may be used as a solvent such as xylene or cyclohexane. It may be in the state of an uncured solution dispersed in. In the case of a resin sheet, a so-called RCC (RESIN COATE
D COPER: resin-coated copper foil). The cycloolefin-based resin may contain a flame retardant such as aluminum hydroxide, magnesium hydroxide, and phosphate ester.

The polyolefin resin may contain an organic filler. By including the organic filler, for example, when a via hole is formed by irradiating the interlayer resin insulating layer with laser light, a via hole opening having a desired shape can be formed well.

That is, when an opening for a via hole or the like is formed by irradiating an infrared laser such as a carbon dioxide gas laser, the organic filler serves as a buffer against heat.
Partially absorbs generated heat and heat reflected from conductor circuits.
In addition, the organic filler serves as a mechanical reinforcing agent for maintaining the resin composition in a predetermined shape, and as a result, the shape of the surrounding resin can be maintained, and the via hole having a desired shape can be maintained. Openings and the like can be formed.

In the case of forming a via hole opening or the like by irradiating an ultraviolet laser, the organic filler absorbs the ultraviolet light, so that the interlayer resin insulation layer in the portion irradiated with the ultraviolet laser decomposes and disappears. Via holes and the like having a desired shape can be formed.

Therefore, when a via hole opening is formed by irradiating the laser and a via layer is formed by forming a metal layer in this opening, the metal layer is in close contact with the underlying conductor circuit and is not easily peeled off. The connectivity and reliability of the obtained multilayer printed wiring board are improved.

The organic filler is not particularly limited. For example, melamine, phenol resin,
Epoxy resin, polyimide resin, fluororesin, PPO,
PPE and the like. These compounds may be used alone or in combination of two or more.

The content of the organic filler is preferably 5 to 60% by weight. The content of the organic filler is 5% by weight
If it is less than 10%, the content of the organic filler is too small, so that the above-mentioned role cannot be fulfilled when irradiating the laser beam, and in some cases, it is not possible to form a via hole opening or the like having a desired shape. is there. On the other hand, if the content of the organic filler exceeds 60% by weight, the characteristics of the polyolefin-based resin are lost, and, for example, the dielectric constant may be excessively high. A more preferable content of the organic filler is 14 to 60% by weight.

The shape of the organic filler is not particularly limited and includes, for example, a spherical shape and a polygonal shape. Among these, cracks are less likely to occur, and stress is generated in the interlayer resin insulating layer by heat or thermal shock. However, a spherical shape is preferable because the stress is easily alleviated.

The particle size of the organic filler is 0.0
5 to 0.2 μm is preferred. When the particle size of the organic filler is less than 0.05 μm, the particle size is too small, so that it may be difficult to mix the organic filler uniformly, while the particle size of the organic filler is 0.2 μm If the ratio exceeds the above range, the particle size of the organic filler may be too large, so that the organic filler may not be completely decomposed and removed when irradiated with laser light.

When the above-mentioned organic filler is compounded, two or more kinds of organic fillers having different particle diameters may be mixed. However, if too many kinds of organic fillers having different particle diameters are mixed, the organic fillers are liable to aggregate. When the size of the agglomerate exceeds 0.2 μm and the same inconvenience as the case where the agglomerate exceeds 0.2 μm is used, there are cases where two types of organic fillers having different diameters are blended. It is desirable to keep the formulation.

Examples of the polyphenylene ether resin include a thermoplastic polyphenylene ether resin having a repeating unit represented by the following chemical formula (1) and a thermosetting polyphenylene ether resin having a repeating unit represented by the following chemical formula (2) And the like.

[0056]

Embedded image

(In the formula, n represents an integer of 2 or more.)

[0058]

Embedded image

(In the formula, m represents an integer of 2 or more. R ¹ and R ² represent a methylene group, an ethylene group or —C
Represents H ₂ —O—CH ₂ —, both of which may be the same or different. )

The thermoplastic polyphenylene ether resin having a repeating unit represented by the above chemical formula (1) has a structure in which a methyl group is bonded to a benzene ring, but the polyphenylene ether which can be used in the present invention. The resin may be a derivative in which the above-mentioned methyl group is substituted with another alkyl group such as an ethyl group, or a derivative in which hydrogen of a methyl group is substituted with fluorine.

Examples of the thermoplastic resin include polyethersulfone and polysulfone. Further, the composite of the thermosetting resin and the thermoplastic resin (resin composite) is not particularly limited as long as it contains a thermosetting resin and a thermoplastic resin, and specific examples thereof include, for example, And a resin composition for forming a roughened surface.

As the resin composition for forming a roughened surface, for example, 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 is used. Examples thereof include those in which a substance soluble in a roughening liquid comprising at least one selected from an acid, an alkali, and an oxidizing agent is dispersed. Note that the terms "sparingly soluble" and "soluble" are referred to as "soluble" for convenience when a substance having a relatively high dissolution rate is immersed in the same roughening solution for the same time, and the relative dissolution rate is relatively low. The slower one is called "poorly soluble" for convenience.

The heat-resistant resin matrix is preferably a matrix capable of maintaining the shape of the roughened surface when the roughened surface is formed on the interlayer resin insulating layer using the roughening solution. , Thermoplastic resins, and composites thereof. Further, by using a photosensitive resin, an opening for a via hole may be formed in the interlayer resin insulating layer by using exposure and development processes.

The thermosetting resin includes, for example, epoxy resin, phenol resin, polyimide resin, polyolefin resin, fluorine resin and the like. When the thermosetting resin is photosensitized, the thermosetting group is subjected to a (meth) acrylation reaction using methacrylic acid, acrylic acid, or the like. Particularly, a (meth) acrylate of an epoxy resin is desirable. Further, an epoxy resin having two or more epoxy groups in one molecule is more desirable. In addition to being able to form the above-described roughened surface, it is also excellent in heat resistance and the like, so that stress is not concentrated on the conductor circuit even under heat cycle conditions, and the conductor circuit and the interlayer resin insulation layer Peeling hardly occurs between the substrate and the substrate.

Examples of the thermoplastic resin include phenoxy resin, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide and the like. These may be used alone or in combination of two or more.

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.

Examples of the inorganic particles include aluminum compounds, calcium compounds, potassium compounds, magnesium compounds, and silicon compounds. These may be used alone or in combination of two or more.

Examples of the aluminum compound include alumina and aluminum hydroxide, and examples of the calcium compound include calcium carbonate and
Calcium hydroxide and the like, as the potassium compound, for example, potassium carbonate and the like, as the magnesium compound, for example, magnesia, dolomite, basic magnesium carbonate, talc and the like,
Examples of the silicon compound include silica and zeolite. These may be used alone or 2
More than one species may be used in combination.

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 those made of a thermosetting resin, a thermoplastic resin, and the like. When immersed in a roughening solution comprising at least one selected from acids, alkalis and oxidizing agents, There is no particular limitation as long as the dissolution rate is faster than the heat-resistant resin matrix,
Specifically, for example, amino resin (melamine resin, urea resin, guanamine resin, etc.), epoxy resin, phenol resin, phenoxy resin, polyimide resin, polyphenylene resin, polyolefin resin, fluororesin, bismaleimide-triazine resin and the like can be mentioned. . These may be used alone or in combination of two or more.

The epoxy resin can be arbitrarily produced by dissolving it in an acid or an oxidizing agent or hardly soluble in the same by selecting the type of 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 cured beforehand. 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, aluminum, nickel, iron, lead, and the like. These may be used alone or in combination of two or more. The metal particles may have a surface layer coated with a resin or the like in order to ensure insulation.

The rubber particles include, for example, acrylonitrile-butadiene rubber, polychloroprene rubber, polyisoprene rubber, acrylic rubber, polysulfur-based rigid rubber, fluorine rubber, urethane rubber, silicone rubber, ABS resin and the like.

As the rubber particles, for example, various modified polybutadiene rubbers such as polybutadiene rubber, epoxy-modified, urethane-modified, (meth) acrylonitrile-modified, and (meth) acrylonitrile-butadiene rubber containing a carboxyl group are used. Can also. By using these rubber particles, the rubber particles are easily dissolved in an acid or an oxidizing agent. In other words, when dissolving the rubber particles using an acid, an acid other than a strong acid can be dissolved, and when dissolving the rubber particles using an oxidizing agent, permanganic acid having a relatively weak oxidizing power can be used. Can be dissolved. Even when chromic acid is used, it can be dissolved at a low concentration. Therefore, no acid or oxidizing agent remains on the surface of the interlayer resin insulating layer, and as described later,
When a catalyst such as palladium chloride is applied after the formation of the roughened surface, no catalyst is applied or the catalyst is not oxidized. These may be used alone or in combination of two or more.

When two or more of the above-mentioned soluble substances are used in combination, the combination of the two soluble substances to be mixed is preferably a combination of resin particles and inorganic particles. Both have low conductivity, so that the insulation of the interlayer resin insulation layer can be ensured, the thermal expansion can be easily adjusted with the poorly soluble resin, and the interlayer resin made of the resin composition for forming a roughened surface can be easily obtained. This is because no crack occurs in the insulating layer, and no peeling occurs between the interlayer resin insulating layer and the conductor circuit.

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 curing agent. And the like. Examples of the liquid phase rubber include the above-mentioned polybutadiene rubber, various modified polybutadiene rubbers such as epoxy-modified, urethane-modified and (meth) acrylonitrile-modified, and uncured solutions such as (meth) acrylonitrile-butadiene rubber containing a carboxyl group. Can be used.

When the photosensitive resin composition is prepared using the liquid phase resin or the liquid phase rubber, the heat-resistant resin matrix and the soluble substance are not uniformly compatible (that is, the phases are separated). As such, these materials need to be selected. 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 photosensitive resin composition in which "islands" of a heat-resistant resin matrix are dispersed in a "sea" of a liquid phase resin or a liquid phase rubber can be prepared.

After the photosensitive resin composition in such a state is cured, the roughened surface can be formed by removing the "sea" or "island" liquid phase resin or liquid phase rubber. .

Examples of the acid used as the roughening solution include phosphoric acid, hydrochloric acid, sulfuric acid, nitric 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, it is desirable to use, for example, an aqueous solution of chromic acid, chromic sulfuric acid, or an alkaline permanganate (such as potassium permanganate). As the alkali, an aqueous solution of sodium hydroxide, potassium hydroxide or the like is desirable.

The average particle size of the soluble substance is 10 μm
The following is desirable. Further, coarse particles having a relatively large average particle diameter of 2 μm or less and fine particles having a relatively small average particle diameter may be used in combination. That is, a soluble substance having an average particle size of 0.1 to 0.5 μm and an average particle size of 1
Combination with a soluble substance of ２2 μm, and the like.

As described above, by combining the coarse particles having a relatively large average particle and the fine particles having a relatively small average particle diameter, the residue of dissolution of the electroless plating film is eliminated, and the amount of the palladium catalyst under the plating resist is reduced. In addition, a shallow and complicated roughened surface can be formed. Further, by forming a complicated roughened surface, a practical peel strength can be maintained even if the unevenness of the roughened surface is small. The coarse particles have an average particle size of more than 0.8 μm and 2.0 μm.
m, the fine particles have an average particle size of 0.1 to 0.8 μm
It is desirable that

By combining the above coarse particles and fine particles, a shallow and complicated roughened surface can be formed because if the used particle size is coarse and the average particle size is less than 2 μm, these fine particles can be formed. 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. By forming such a complicated roughened surface, a practical peel strength can be maintained even with a shallow roughened surface.

In this case, if the particle diameter used is coarse and the average particle diameter is less than 2 μm, the roughening proceeds too much and no voids are generated. Excellent in nature. In the resin composition for forming an interlayer surface, the particle size of the soluble substance is the length of the longest portion of the soluble substance.

The coarse particles have an average particle size of more than 0.8 μm and less than 2.0 μm, and the fine particles have an average particle size of 0.1 μm.
When the thickness is approximately 0.8 μm, the depth of the roughened surface is approximately Rmax =
With the semi-additive method, not only the electroless plating film can be easily removed by etching, but also the Pd catalyst under the electroless plating film can be easily removed,
Further, a practical peel strength of 1.0 to 1.3 kg / cm can be maintained.

The shape of the soluble substance is not particularly limited, and examples thereof include a spherical shape and a crushed shape. Further, the shape of the soluble substance is desirably a uniform shape. This is because a roughened surface having unevenness with a uniform roughness can be formed.

The above resin composition for forming a roughened surface may contain an organic solvent so that it can be applied on a substrate or the like. (Hereinafter also referred to as a resin film for forming a roughened surface) is desirable. This is because, when forming the interlayer resin insulation layer, if the resin composition for forming a roughened surface is in a liquid state, in a kneading step or a coating step, control items such as temperature and humidity increase, This is because the roughened surface forming resin film is easy to handle. When the above-mentioned resin composition for forming a roughened surface contains an organic solvent, the content is preferably 10% by weight or less.

In the above resin film for forming a roughened surface,
It is desirable that the soluble substance is substantially uniformly dispersed in the heat resistant resin matrix. It is possible to form a roughened surface with unevenness of uniform roughness, and even if via holes and through holes are formed in the resin film, it is possible to secure the adhesion of the metal layer of the conductor circuit formed thereon. Because you can. Further, the above-mentioned resin film for forming a roughened surface may be formed so as to contain a soluble substance only in a surface layer portion forming a roughened surface. Thereby, since the portions other than the surface layer portion of the roughened surface forming resin film are not exposed to the acid or the oxidizing agent, the insulation between the conductor circuits via the interlayer resin insulating layer is reliably maintained.

In the above resin film for forming a roughened surface,
The amount of the soluble substance dispersed in the hardly soluble resin is
The content is preferably 3 to 40% by weight based on the resin film for forming a roughened surface. If the amount of the soluble substance is less than 3% by weight,
In some cases, a roughened surface having desired irregularities cannot be formed. If the amount exceeds 40% by weight, when a soluble substance is dissolved using an acid or an oxidizing agent, the substance is dissolved to a deep portion of the resin film. In addition, the insulation between the conductor circuits via the interlayer resin insulation layer made of the resin film cannot be maintained, which may cause a short circuit.

The above-mentioned roughened surface forming resin film desirably contains a curing agent and other components in addition to the above-mentioned soluble substance and the above-mentioned heat-resistant resin matrix. Examples of the curing agent include imidazole-based curing agents, amine-based curing agents, guanidine-based curing agents, epoxy adducts of these curing agents and those obtained by microencapsulating these curing agents, triphenylphosphine, and tetraphenylphosphonate. Organic phosphine-based compounds such as ammonium tetraphenylborate.

The content of the curing agent is desirably 0.05 to 10% by weight based on the resin film for forming a roughened surface. If the content is less than 0.05% by weight, the degree of curing of the roughened surface forming resin film is insufficient, so that the degree of penetration of acid or oxidizing agent into the roughened surface forming resin film increases. The insulation of the film may be impaired. On the other hand, when the content exceeds 10% by weight, an excessive curing agent component may modify the composition of the resin, which may cause a decrease in reliability.

[0092] Examples of the other components include fillers such as inorganic compounds or resins which do not affect the formation of the roughened surface. As the inorganic compound, for example,
Examples of the resin include silica, alumina, and dolomite. Examples of the resin include a polyimide resin, a polyacryl resin, a polyamideimide resin, a polyphenylene resin, a melanin resin, and an olefin resin. By incorporating these fillers, the performance of the printed wiring board can be improved by matching the thermal expansion coefficient, improving heat resistance and chemical resistance, and the like.

Further, the resin film for forming a roughened surface is
A solvent may be contained. Examples of the solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethyl acetate, butyl acetate, and aromatic hydrocarbons such as cellosolve acetate, toluene, and xylene. These may be used alone or in combination of two or more.

The thickness of the interlayer resin insulation layer is not particularly limited, but is preferably 5 to 50 μm. When the thickness is less than 5 μm, insulation between the vertically adjacent conductor circuits may not be maintained. On the other hand, when the thickness is more than 50 μm, when a non-through hole or the like is formed, resin residue may remain on the bottom thereof. It may be generated or the shape of the non-through hole or the like may be tapered toward the bottom. Such a multilayer printed wiring board of the present invention can be manufactured, for example, by a method for manufacturing a multilayer printed wiring board of the present invention described later.

Next, a method for manufacturing a multilayer printed wiring board according to the present invention will be described. The method for manufacturing a multilayer printed wiring board according to the present invention is characterized by including at least the following steps (A) to (I). (A) a through-hole forming step of forming a through-hole in a substrate having a lower conductor circuit and a lower interlayer resin insulating layer formed on both surfaces thereof; and (B) a wall surface of the through-hole and the lower interlayer resin insulating layer. A conductor layer forming step of forming a conductor layer on a part of the surface,
(C) An epoxy resin, a curing agent, and inorganic particles are contained in the through-hole having the conductor layer formed on the wall surface thereof, and the content of the inorganic particles after curing is 10 to 50% by weight. A resin filling step of filling the resin composition, (D) a drying step of drying the resin composition for filling the through hole, and (E) a polishing treatment on the surface of the resin composition for filling the through hole exposed from the through hole. (F) a through-hole forming step of curing the resin composition for filling a through-hole and forming a through-hole having a resin filler layer formed therein;
(G) a cover plating layer forming step of forming a conductor layer covering a surface portion of the resin filler layer as a part of a conductor circuit; (H) a via on a lower interlayer resin insulation layer having a conductor layer formed on its surface; An upper interlayer resin insulating layer forming step of laminating and forming an upper interlayer resin insulating layer having a hole opening; and (I) a via hole forming step of forming a conductor layer in the via hole opening.

In the method for manufacturing a multilayer printed wiring board according to the present invention, the resin composition for filling a through hole containing inorganic particles is filled in the through hole, and then the surface of the resin composition for filling a through hole exposed from the through hole is filled. , A through hole having a flat surface layer portion can be formed. Therefore, when an interlayer resin insulating layer is further formed by lamination, a swell or the like does not occur in the formed interlayer resin insulating layer, and a multilayer printed wiring board having excellent reliability can be manufactured. Further, in the above production method, since the content ratio of the inorganic particles of the resin composition for filling a through-hole is in the above range, the surface of the resin composition for filling a through-hole exposed from the through-hole can be easily flattened. it can. The reason will be described below.

Conventionally, as a resin composition for filling through-holes,
For example, a resin composition having a content ratio of inorganic particles of more than 50% by weight has been used. In such a resin composition for filling a through hole having a high content ratio of such inorganic particles, the surface exposed from the through hole is flattened. In order to perform a plurality of polishing processes, first, a hard polishing object is subjected to a rough polishing process by belt sander polishing or the like to be polished, and then a polishing process using fine abrasive grains such as buff polishing is performed. Had to be applied.
Here, in the belt sander polishing treatment or the like, the inorganic particles may fall off, or cracks may occur in the resin composition for filling the through holes or the interlayer resin insulating layer, which may lead to defects.

On the other hand, the resin composition for filling through holes used in the production method of the present invention has a content ratio of 10 to 5 after curing.
Since it contains 0% by weight of inorganic particles, the surface of the resin composition for filling the through-holes exposed from the through-holes can be planarized only by polishing using fine abrasive grains such as buffing. This is because the content ratio of the inorganic particles is small, so that the absolute amount of the inorganic particles existing in the exposed portion is reduced. In addition, when flattening is performed only by a fine polishing treatment such as buffing, inorganic particles are less likely to be dropped and cracks are not easily generated in the resin composition for filling through holes.

In the manufacturing method of the present invention, after forming the resin filler layer, a conductor layer (cover plating layer) covering the resin filler layer is formed. This resin filler layer is formed as described above. Since it contains 10 to 50% by weight of inorganic particles, it is suitable for forming a lid plating layer. This is because the content ratio of the inorganic particles in the resin filler layer is small, so that the absolute amount of the inorganic particles present in the surface layer portion of the resin filler layer is small. A catalyst for electroless plating such as Pd is unlikely to adhere to the surface of the inorganic particles, and it is difficult to form a uniform electroless plating layer when the inorganic particles are present in a large amount at a portion to be plated. In addition, the wetting of the electroless plating solution to the inorganic particles is poorer than the wetting of the electroless plating solution to the resin, and when the inorganic particles are present in a large amount in the portion to be plated, a uniform electroless plating layer is formed. Can not do. However, since the resin filler layer formed by the production method of the present invention has a small absolute amount of the inorganic particles existing in the surface layer portion, the electroless plating film can be favorably formed.

In the above manufacturing method, the conductor layer covering the surface portion of the resin filler layer is formed as a part of the conductor circuit, and the via hole is formed on the conductor layer. It is possible to manufacture a multilayer printed wiring board having a short length and corresponding to an increase in the speed of an IC chip. Furthermore, the multilayer printed wiring board obtained by the production method of the present invention is less likely to cause cracks in the resin filler layer even under heat cycle conditions, and peeling between the resin filler layer and the lid plating layer is also prevented. Since it hardly occurs, the connection reliability is excellent.

Here, first, the steps (A) to (I) of the method for manufacturing a multilayer printed wiring board will be described, and all the manufacturing steps including the steps (A) to (I) will be described. Details will be described later. In the step (A) (through-hole forming step) of the method for manufacturing a multilayer printed wiring board according to the present invention, a through-hole is formed on a substrate having a lower conductor circuit and a lower interlayer resin insulating layer formed on both surfaces thereof. To form In this specification, a conductor circuit and an interlayer resin insulation layer formed directly above a substrate are referred to as a lower conductor circuit and a lower interlayer resin insulation layer, respectively, as necessary. The conductor circuit and the interlayer resin insulation layer further laminated on the layer are distinguished by the upper conductor circuit and the upper interlayer resin insulation layer, respectively.

The through holes can be formed by drilling, laser processing, or the like. In addition, when the material of the substrate has a reinforcing material such as a glass epoxy resin,
It is desirable to form a through hole by drilling. The diameter of the through hole is not particularly limited, and may be appropriately selected in consideration of the wiring density of the multilayer printed wiring board. However, in the case of a high-density wiring board, the diameter is usually about 100 to 400 μm.

After the formation of the through hole, the wall surface of the through hole may be subjected to desmear treatment. This is because by performing the desmear treatment, the adhesion to the conductor layer formed in a later step is improved. The desmear treatment can be performed using, for example, an oxidizing agent composed of an aqueous solution such as chromic acid and permanganate. Alternatively, the treatment may be performed by oxygen plasma, mixed plasma of CF ₄ and oxygen, corona discharge, or the like. A method for manufacturing a substrate in which a conductor circuit and an interlayer resin insulating layer are formed on both surfaces thereof will be described later.

In the step (B) (conductor layer forming step), after forming a through hole in the substrate, a conductor layer is formed on the wall surface of the through hole and a part of the surface of the lower interlayer resin insulating layer. Form. In this step, the conductor layer formed on the wall surface of the through hole constitutes a through hole, and the conductor layer formed on a part of the surface of the lower interlayer resin insulation layer becomes an upper conductor circuit. Alternatively, a via hole opening may be formed in the lower interlayer resin insulation layer in advance, and when a conductor layer is formed in this step, a conductor layer may be formed also in the via hole opening to form a via hole. By forming the via hole, the lower conductor circuit and the upper conductor circuit sandwiching the lower interlayer resin insulation layer can be electrically connected.

The conductor layer can be formed by, for example, electroless plating. Further, the conductor layer may be formed by a sputtering process instead of the electroless plating process, or both may be used together to form a conductor layer composed of a plurality of layers. Further, a conductor layer including an electroless plating layer and an electrolytic plating layer may be formed by laminating an electrolytic plating layer on the electroless plating layer.

Of these, a conductor layer composed of an electroless plating layer and an electrolytic plating layer is desirable. In particular, the conductor layer (upper conductor circuit) formed on a part of the surface of the lower interlayer resin insulation layer is as follows. For this reason, such a configuration is desirable. By forming the electroless plating layer in the lower layer, a conductor layer having excellent followability to the surface of the interlayer resin insulating layer can be formed, particularly when a roughened surface is formed on the surface of the interlayer resin insulating layer. In addition, a conductor layer having excellent followability and adhesion to the roughened surface can be formed. Further, when an electrolytic plating layer is formed on this electroless plating layer, the electrolytic plating layer is softer and more malleable than the electroless plating layer, so even if the substrate is warped during a heat cycle. Accordingly, it is possible to follow the dimensional change of the interlayer resin insulating layer. Therefore, by forming a conductor circuit composed of the electroless plating layer and the electrolytic plating layer,
A multilayer printed wiring board having excellent connection reliability can be manufactured. When performing the electroless plating treatment, a catalyst is previously applied to a portion to be plated. Examples of the catalyst include palladium and the like.

Of the conductor layers formed in this step, the conductor layer formed on the wall surface of the through hole may be formed uniformly over the entire wall surface in order to form a through hole. Since the conductor layer formed on a part of the surface becomes an upper layer conductor circuit, it must be formed according to the wiring pattern. A method for forming a conductor layer according to the wiring pattern on the surface of the lower interlayer resin insulation layer will be described later.

After the formation of the conductor layer, it is desirable to form a roughened surface on at least a part of the surface of the conductor layer. This is because the adhesion to the resin filler layer and the upper interlayer resin insulation layer can be improved. Examples of the method of forming the roughened surface include a blackening (oxidation) -reduction treatment, an etching treatment, and a treatment using a Cu-Ni-P needle-like alloy plating.

As a specific method of the blackening (oxidation) -reduction treatment, NaOH (10 to 20 g / l), NaCl
O ₂ (40 to 50 g / l), Na ₃ PO ₄ (6 to 15 g
/ L), a blackening treatment using an aqueous solution containing (Na) (2.7 to 10 g / l), NaB
A method of performing a reduction treatment using an aqueous solution containing H ₄ (1.0 to 6.0 g / l) as a reduction bath is exemplified.

As an etchant used for the above etching treatment, a mixed solution of an organic acid and a cupric complex is desirable. When the mixed solution of the organic acid and the cupric complex is used as an etching solution, the reaction between the etching solution and a conductor layer made of copper or the like in the coexistence of oxygen, ie, the following reaction formulas (3) and (4) The illustrated reaction proceeds, and the conductor layer is etched.

[0111]

Embedded image

Note that the above reaction formulas (3) and (4)
This is a reaction formula that proceeds when the material of the conductor layer is copper.

The above-mentioned organic acids are added to dissolve copper oxide. Specific examples thereof include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and the like.
Examples include acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, benzoic acid, glycolic acid, lactic acid, malic acid, and sulfamic acid.
These may be used alone or in combination of two or more. In the etching solution, the content of the organic acid is desirably 0.1 to 30% by weight. This is because the solubility of the oxidized copper can be maintained and the stability of the catalyst can be ensured. Note that the generated cuprous complex is dissolved by the action of an acid and combines with oxygen to form a cupric complex, which again contributes to copper oxidation. Further, in addition to the above organic acids, inorganic acids such as borofluoric acid, hydrochloric acid and sulfuric acid may be added.

The cupric complex is preferably an azole cupric complex. 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, tetrazole and the like. Among these, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-undecylimidazole are desirable. In the etching solution, the content of the cupric complex 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.

The etching solution comprising the mixed solution of the organic acid and the cupric complex may contain fluorine ions, chlorine ions, bromine ions, etc. in order to dissolve copper and to assist the oxidizing action of azoles. Good. The halogen ions can be supplied by adding hydrochloric acid, sodium chloride, or the like to the mixed solution. The amount of the supplied halogen ions is preferably 0.01 to 20% by weight. This is because the roughened surface formed by the etching solution containing halogen ions in this range has excellent adhesion to the resin filler layer and the upper interlayer resin insulation layer. In addition,
The mixed solution of the organic acid and the cupric complex is prepared by dissolving a cupric complex of an azole, an organic acid and, if necessary, a halogen ion in water.

As the plating treatment, for example, copper sulfate (1 to 40 g / l), nickel sulfate (0.1 to 6.0 g / l)
/ L), citric acid (10-20 g / l), sodium hypophosphite (10-100 g / l), boric acid (10-40 g / l)
g / l) and a surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.01 to 10 g / l).
= 9 in the electroless plating bath, Cu-
A method of forming a roughened layer made of a Ni-P alloy is exemplified. This is because the crystal structure of the plating 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 compound.

Further, in the step (C) (resin filling step), an epoxy resin, a curing agent, and inorganic particles are contained in the through-hole having the conductor layer formed on the wall thereof, and the cured inorganic material is contained in the through-hole. The resin composition for filling through-holes having a particle content of 10 to 50% by weight is filled. Specific examples of the epoxy resin, the curing agent, and the inorganic particles contained in the resin composition for filling a through-hole include those similar to those contained in the resin filler of the multilayer printed wiring board of the present invention.

The resin composition for filling the through-holes may contain other thermosetting resins or thermoplastic resins in addition to the above-mentioned epoxy resin. Specific examples of the other thermosetting resins and thermoplastic resins include those similar to those contained in the resin filler of the multilayer printed wiring board of the present invention. Further, these thermosetting resins and thermoplastic resins can be used instead of epoxy resins.

Further, the resin composition for filling through-holes may be made of N
MP (normal methylpyrrolidone), DMDG (diethylene glycol dimethyl ether), glycerin, water,
A solvent such as cyclohexanol, cyclohexanone, methylcellosolve, methylcellosolve acetate, methanol, ethanol, butanol, and propanol may be contained, but a solvent containing no solvent is desirable. When the resin composition for filling a through-hole contains a solvent, the solvent has to be removed in a subsequent drying step, but it is difficult to completely remove the solvent, and the resin composition for filling a through-hole has a problem. When the curing treatment is performed while the solvent remains in the resin, the solvent evaporates due to the heat treatment at the time of curing or the heat treatment in the post-process, and this causes cracks to occur in the resin filler layer or the resin filler layer and the resin. This may cause peeling between the conductor layer (cover plating layer) covering the filler layer and the like.

The resin composition for filling through-holes contains inorganic particles so that the content ratio after curing is 10 to 50% by weight, so that the viscosity suitable for filling into the through-holes is high. have. That is, when the content ratio of the inorganic particles is less than 10% by weight, the viscosity of the resin composition for filling through holes is low,
Through-hole filling resin composition filled from one end of the through-hole,
It may flow out from the other end of the through hole. When the content ratio exceeds 50% by weight, problems caused by viscosity hardly occur when the resin composition for filling through holes is filled, but as described above, inconvenience occurs during polishing. As described later, inconvenience occurs during electroless plating.

As a method of filling the resin composition for filling a through hole into the through hole, for example, a mask having an opening in a portion corresponding to the through hole is formed by forming a lower conductive circuit and a lower interlayer resin insulating layer. Or a method of filling with a squeegee or applying a resin composition for filling through holes using a printing machine on a substrate on which a lower conductive circuit and a lower interlayer resin insulating layer are formed. Thus, a method of filling the through hole with the resin composition for filling a through hole can be used.
When the via hole is formed in the step (B), the via hole may be filled with the resin composition for filling a through hole in this step.

Further, in the step (D) (drying step), the filled resin composition for filling through holes is dried. Specific drying conditions are not particularly limited, and may be appropriately selected in consideration of the composition and the like of the resin composition for filling through holes.
Usually, it is carried out at 50 to 180 ° C. for about 20 to 90 minutes.

Further, in the step (E) (polishing step), the surface of the resin composition for filling the through hole exposed from the through hole is subjected to a polishing treatment. The polishing step is desirably at least one buff polishing process. This is because, as described above, in the buffing treatment, the inorganic particles hardly fall off and cracks hardly occur in the resin composition for filling the through holes. In addition, the polishing process,
This may be performed after the resin composition for filling the through hole is semi-cured.

Further, in the step (F) (through-hole forming step), the resin composition for filling through-holes is cured to form through-holes in which a resin filler layer is formed. The curing conditions of the resin composition for filling a through-hole are not particularly limited, and may be appropriately selected in consideration of the composition of the resin composition for filling a through-hole.
For about 20 to 90 minutes. In addition, the curing treatment performed here may be step curing in which the temperature is gradually changed from a low temperature to a high temperature to perform curing as needed.

Further, in the step (G) (cover plating layer forming step), a conductor layer (cover plating layer) covering the resin filler layer is formed as a part of the conductor circuit. In the method of manufacturing a multilayer printed wiring board according to the present invention, the resin plating layer having a flat surface exposed from the through-hole can be easily formed by passing through the polishing step. Suitable to do.

It is preferable that the cover plating layer is formed by using electroless plating. Since the resin filler layer formed by the production method of the present invention has an inorganic particle content of 10 to 50% by weight, it is suitable for forming a lid plating layer using electroless plating as described above. Because there is. After the electroless plating, electrolytic plating may be performed to adjust the thickness of the cover plating layer. After forming the lid plating layer, a roughened surface may be formed on the surface of the lid plating layer. As a method of forming the roughened surface, for example, a method similar to the method used in the above-described conductor layer forming step can be used.

Further, in the step (H) (the step of forming the upper interlayer resin insulating layer), an upper interlayer resin insulating layer having a via hole opening is formed on the lower interlayer resin insulating layer. Specifically, for example, the upper interlayer resin insulation layer can be formed by using the following method. That is, first, an uncured resin insulating layer made of a thermosetting resin or a resin composite is formed on a lower interlayer resin insulating layer in which a conductor layer is formed on a part of the surface thereof, or from a thermoplastic resin. A resin layer is formed. The uncured resin insulating layer is formed, for example, by applying an uncured resin with a roll coater, a curtain coater, or the like, or by uncured (semi-cured).
The resin film is formed by thermocompression bonding. The resin layer made of a thermoplastic resin is formed by, for example, thermocompression bonding a resin molded body formed into a film.

When the upper interlayer resin insulation layer is formed by applying the uncured resin, a heat treatment is performed after the resin is applied. By performing the above heat treatment,
Uncured resin can be thermally cured (semi-cured).
The thermal curing may be performed after forming the via hole opening in some cases.

When the upper interlayer resin insulation layer is formed by attaching the above resin film, the upper interlayer resin insulation layer is formed by, for example, using a vacuum laminator or the like under reduced pressure or vacuum. This is performed by compressing the film and then thermosetting the resin film. In addition, instead of the method of thermosetting after pressing the resin film, the pressing of the resin film may be performed while heating. The thermal curing may be performed after forming the via hole opening in some cases.

When the upper interlayer resin insulation layer is formed by thermocompression bonding of a thermoplastic resin formed into a film, the film is formed under reduced pressure or vacuum using an apparatus such as a vacuum laminator. The compressed thermoplastic resin is pressed.

When forming an upper interlayer resin insulation layer using a thermosetting resin or a resin composite as the material, the uncured resin insulation layer is subjected to a curing treatment and a via hole opening is formed. Then, an upper interlayer resin insulation layer is formed. The via hole opening is desirably formed by laser processing. The laser processing may be performed before the curing processing or may be performed after the curing processing. In the case where an upper interlayer resin insulating layer made of a photosensitive resin is formed, an opening for a via hole may be provided by performing exposure and development processes. In this case, the exposure and development processes are performed before the above-described curing process.

When an upper interlayer resin insulation layer using a thermoplastic resin as the material is formed, a via hole opening is formed in the resin layer made of the thermoplastic resin by laser treatment, and the upper interlayer resin insulation layer is formed. It can be.

At this time, as a laser to be used, for example, a carbon dioxide laser, an excimer laser, a UV laser,
An AG laser and the like can be mentioned. These lasers may be properly used in consideration of the shape of the via hole opening to be formed.

When forming the via hole opening,
By irradiating laser light with a hologram excimer laser through a mask, a large number of via hole openings can be formed at once. Further, when the via hole opening is formed using a short-pulse carbon dioxide laser, the amount of resin remaining in the opening is small, and the damage to the resin at the periphery of the opening is small.

By irradiating a laser beam through an optical lens and a mask, a large number of via hole openings can be formed at once. This is because a plurality of portions can be simultaneously irradiated with laser light having the same intensity and the same irradiation angle through the optical lens and the mask.

The through hole formed in the mask is desirably a perfect circle in order to make the spot shape of the laser beam a perfect circle, and the diameter of the through hole is desirably about 0.1 to 2 mm. When the carbon dioxide laser is used, the pulse interval is desirably 10 ⁻⁴ to 10 ⁻⁸ seconds. The time for irradiating the laser for forming the opening is preferably 10 to 500 μsec.

When an opening for a via hole is formed by a laser beam, particularly when a carbon dioxide gas laser is used, desmearing is preferably performed. The desmear treatment can be performed using an oxidizing agent composed of an aqueous solution such as chromic acid and permanganate. In addition, oxygen plasma, CF ₄
It may be treated by a mixed plasma of oxygen and oxygen, corona discharge, or the like. The surface can also be modified by irradiating ultraviolet rays using a low-pressure mercury lamp.

The thickness of the upper interlayer resin insulation layer is not particularly limited, but is preferably 5 to 50 μm. Further, the opening diameter of the via hole opening is not particularly limited,
Usually, 40 to 200 μm is desirable.

After forming the upper interlayer resin insulating layer having the via hole opening through the above steps, the surface of the upper interlayer resin insulating layer including the inner wall of the via hole opening is roughened using an acid or an oxidizing agent. A surface may be formed. Examples of the acid include sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, and formic acid. Examples of the oxidizing agent include chromic acid, chromic sulfuric acid, and permanganates such as sodium permanganate. Further, the formation of the roughened surface may be performed by using a plasma treatment or the like.

Specifically, when the upper interlayer resin insulation layer is formed using a resin composition for forming a roughened surface, it is desirable to form the roughened surface using an acid or an oxidizing agent, In the case of using a resin or the like, it is desirable to form a roughened surface using a plasma treatment or the like. When the roughened surface is formed using an acid, an aqueous solution such as an alkali is used, and when the roughened surface is formed using an oxidizing agent, the inside of the via hole opening is neutralized using a neutralizing solution. . By this operation, the acid and the oxidizing agent are removed so that the next step is not affected.

Further, in the step (I) (via hole forming step), a conductor layer is formed in the via hole opening. The conductor layer can be formed by a method similar to the method used in the step (B) (conductor layer forming step), that is, by an electroless plating treatment, an electrolytic plating treatment, sputtering, or the like. In this step, when the conductor layer is formed in the via hole opening, a conductor layer to be an upper conductor circuit may be formed on a part of the upper interlayer resin insulating layer at the same time. The upper conductor circuit can be formed by using the same method as the first or second upper conductor circuit formation method described later.

Through the steps (A) to (I), the adhesiveness to the conductor layer (conductor layer for through hole) is excellent, and the coefficient of thermal expansion between the interlayer resin insulation layer and the substrate is low. A through hole having a resin filler layer that is aligned,
It has excellent adhesion to the resin filler layer and can form a lid plating layer having a flat surface, and by forming the lid plating layer, a via hole can be formed directly above a through hole. .

Next, all the manufacturing steps of the method for manufacturing a multilayer printed wiring board according to the present invention will be described in the order of steps. (1) In the first method for manufacturing a multilayer printed wiring board of the present invention, first, a lower conductive circuit is formed on a substrate. Specifically, for example, after forming a solid conductor layer by performing electroless plating or the like on both surfaces of the substrate, an etching resist corresponding to the conductor circuit pattern is formed on the conductor layer, and thereafter, etching is performed. What is necessary is just to form by performing. After the electroless plating is performed, the thickness of the conductor layer may be increased by performing the electrolytic plating. Further, a copper-clad laminate, an RCC substrate, or the like may be used as a substrate on which a solid conductor layer is formed.

In place of the above method, for example, the following method may be used. That is, first, a thin conductor layer is formed on the surface of the substrate by electroless plating, sputtering, or the like. Next, a plating resist is formed on a portion of the thin conductor layer where no conductor circuit is formed, and an electroplating layer is formed on the portion where the plating resist is not formed using the thin conductor layer as a plating lead. Further, the lower conductor circuit can be formed on the substrate by peeling off the plating resist and etching away the thin film conductor layer existing under the plating resist.

(2) Next, if necessary, the surface of the lower conductor circuit is roughened. As the roughening treatment method, for example, the above-mentioned blackening (oxidation) -reduction treatment, etching treatment, treatment by Cu-Ni-P needle-like alloy plating, or the like can be used.

(3) Next, an uncured resin insulating layer made of a thermosetting resin or a resin composite is formed on the lower conductive circuit, or a resin layer made of a thermoplastic resin is formed.
The uncured resin insulating layer and the resin layer made of the thermoplastic resin are formed, for example, using the same method as the method used in the above-described upper interlayer resin insulating layer forming step. In addition,
When an uncured resin layer is formed, a resin film having a metal layer such as a copper foil formed on one surface thereof may be attached.

(4) Next, when forming a lower interlayer resin insulation layer using a thermosetting resin or a resin composite as the material, an uncured resin insulation layer is subjected to curing treatment and via holes are formed. Opening is formed to form a lower interlayer resin insulation layer. When forming a lower interlayer resin insulation layer using a thermoplastic resin as the material, an opening for a via hole is formed in a resin layer made of a thermoplastic resin to form a lower interlayer resin insulation layer. The opening for the via hole may be formed by a method similar to the method used in the above-described upper interlayer resin insulating layer forming step, that is, a laser treatment, an exposure development treatment, or the like.

The thickness of the lower interlayer resin insulation layer is not particularly limited, but is usually preferably 5 to 50 μm. Further, the opening diameter of the via hole opening is not particularly limited,
Usually, 40 to 200 μm is desirable.

(5) Next, a roughened surface is formed on the surface of the lower interlayer resin insulation layer including the inner wall of the via hole opening, if necessary, using an acid or an oxidizing agent. Further, the formation of the roughened surface may be performed by using a plasma treatment or the like.

The roughened surface is formed in order to increase the adhesion between the lower interlayer resin insulating layer and the electroless plating film formed thereon, and the roughened surface is formed on the lower interlayer resin insulating layer and the electroless plating film. When there is sufficient adhesiveness between them, it is not necessary to form them.

Thereafter, when the roughened surface is formed by using an acid, an aqueous solution of an alkali or the like is used, and when the roughened surface is formed by using an oxidizing agent, a neutralizing solution is used to clean the inside of the via hole opening. Neutralize. By this operation, the acid and the oxidizing agent are removed so that the next step is not affected. Such (1) ~
Through the step (5), a substrate having a lower conductive circuit and a lower interlayer resin insulating layer formed on both surfaces thereof can be manufactured.

(6) Next, as described in the step (A) (through hole forming step), through holes are formed in the substrate.
This through-hole forming step is performed after performing the above step (4), and when forming the roughened surface in the above step (5), a roughened surface is simultaneously formed on the wall surface of the through hole. Is also good. (7) Next, as described in the above step (B) (conductor layer forming step), a conductor layer is formed on the wall surface of the through hole and a part of the surface of the lower interlayer resin insulating layer. Here, as described above, the formation of the conductor layer forming the through hole and the formation of the conductor layer according to the wiring pattern of the upper conductor circuit (including the via hole) are performed. Therefore, a method of forming a conductor layer according to a wiring pattern will be specifically described.

As described above, when forming the conductor layer by electroless plating, it is necessary to apply a catalyst such as palladium in advance. Before applying the catalyst, the catalyst is removed by removing the residue of the acid or oxidizing agent and modifying the surface of the lower interlayer resin insulation layer by performing a plasma treatment such as oxygen and nitrogen or a dry treatment such as a corona treatment. It is possible to improve the adhesion of the metal during the electroless plating and the adhesion to the lower interlayer resin insulating layer of the electroless plating layer, particularly at the bottom surface of the via hole opening. can get.

First, when a conductor layer (thin film conductor layer) is formed on the wall surface of the through hole by electroless plating or the like, the entire surface of the lower interlayer resin insulation layer (including the inner wall surface of the via hole opening) is simultaneously formed. A thin-film conductor layer is formed. Next, a plating resist is formed on a portion of the thin film conductor layer where the upper conductor circuit is not formed. The plating resist can be formed, for example, by attaching a photosensitive dry film or the like and performing exposure and development processing.

Next, electroplating is performed using the thin-film conductor layer as a plating lead to form an electroplating layer in the portion where the plating resist is not formed.

Further, after forming the electroplating layer, the plating resist is peeled off, and the thin film conductor layer existing under the plating resist is removed by etching. Here, as an etching solution, for example, a sulfuric acid-hydrogen peroxide aqueous solution,
Examples include aqueous solutions of persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate, aqueous solutions of ferric chloride and cupric chloride, hydrochloric acid, nitric acid, hot dilute sulfuric acid and the like. Further, an etching solution containing a cupric complex and an organic acid can also be used.

By using such a method (first upper conductor circuit forming method), an upper conductor circuit can be formed on the lower interlayer resin insulation layer, and at the same time, the lower interlayer resin insulation layer is sandwiched. Via holes for electrically connecting the upper and lower conductor circuits (that is, between the lower conductor circuit and the upper conductor circuit) can also be formed. The via hole opening may be filled with electroplating to form a field via structure.After the electroplating, the via hole opening is filled with a conductive paste or the like, and a lid plating layer is formed thereon. A field via structure may be used.

Further, instead of the above-described first upper layer conductor circuit forming method, an upper layer conductor circuit can be formed by using the following method (second upper layer conductor circuit forming method). That is, first, a thin film conductor layer is formed on the wall surfaces of the through holes and the entire surface of the lower interlayer resin insulation layer, as in the first method of forming the upper conductor circuit.

Next, electroplating is performed using the thin film conductor layer as a plating lead to form an electroplating layer on the entire surface of the thin film conductor layer. Further, an etching resist is formed on the upper conductive circuit forming portion on the electroplating layer.
The etching resist can be formed, for example, by attaching a photosensitive dry film or the like and performing exposure and development processing. Further, the electroplating layer and the thin film conductor layer existing under the portion where the etching resist is not formed are removed by etching. Note that the same etchant as that used in the first method for forming the upper conductor circuit can be used.

By using such a second method for forming an upper conductor circuit, an upper conductor circuit can be formed on the lower interlayer resin insulating layer. In the second upper conductor circuit forming method, the field via structure may be formed by filling the via hole opening when performing the electroplating, and the conductive paste may be filled in the via hole opening after the electroplating is completed. Or the like, and a lid plating layer may be formed thereon to form a field via structure.

(8) Next, as described in the step (C) (resin filling step), the through-hole is filled with the resin composition for filling a through-hole. In this step, the resin composition for filling the through-hole may be filled in the via-hole or between the upper conductor circuits while filling the through-hole with the resin filler. The inside of the via hole is filled with the resin composition for filling a through-hole, and a polishing process described later is performed to flatten the surface layer portion of the layer made of the resin composition for filling a through-hole and the surface of the upper conductive circuit. Therefore, when the upper interlayer resin insulation layer is formed in a later step, the upper interlayer resin insulation layer is less likely to undulate.

(9) Next, as described in the above-mentioned steps (D) (drying step) to (F) (through-hole forming step), the resin composition for filling the through-hole filled in the through-hole is used. Then, drying, polishing, and curing are performed to form through holes.

(10) Next, as described in the step (G) (cover plating layer forming step), the conductor layer (cover plating layer) covering the resin filler layer is formed as a part of the conductor circuit. . (11) Further, as described in the step (H) (the step of forming the upper interlayer resin insulation layer), an upper interlayer resin insulation layer having a via hole opening is formed on the lower interlayer resin insulation layer. .

(12) Further, as described in the step (I) (via hole forming step), a conductor layer is formed in the via hole opening to form a via hole. In the via hole forming step, the upper conductor circuit may be formed simultaneously with the formation of the conductor layer serving as the via hole, or the upper conductor circuit may be formed after forming the conductor layer serving as the via hole. Of course, it is desirable to form the upper conductor circuit and the via hole simultaneously because it is economically advantageous. The upper conductor circuit can be formed by using the above-described first or second upper conductor circuit forming method. After forming the upper conductor circuit as described above, a roughened surface may be formed on the surface of the upper conductor circuit (including the via hole) as necessary.

(13) Next, if necessary, the above (11)
By repeating the steps (12) and (12), the upper conductor circuit and the upper interlayer resin insulation may be further laminated. Before repeating the steps (11) and (12), a resin composition for filling a through hole may be filled in the via hole or between the upper conductor circuits.

(14) Next, a solder resist layer is formed on the surface of the substrate including the uppermost conductive circuit, a solder pad is formed by opening the solder resist layer, and a solder paste is applied to the solder pad. Filling and reflowing form solder bumps. Then, pins are arranged on the connection surface of the external board, or solder balls are formed, so that a PGA (Pin Grid Array) or a BGA (Ball Grid Array) is formed.
Array).

The solder resist layer can be formed by using, for example, a solder resist composition comprising a polyphenylene ether resin, a polyolefin resin, a fluororesin, a thermoplastic elastomer, an epoxy resin, a polyimide resin, and the like. Specific examples include, for example, the same resins as those used for the interlayer resin insulating layer.

Examples of the solder resist composition other than those described above include, for example, (meth) acrylate of novolak type epoxy resin, imidazole curing agent, bifunctional (meth) acrylate monomer, and molecular weight of 500 to 50.
A paste-like fluid containing a polymer of about 00 (meth) acrylate, a thermosetting resin such as a bisphenol-type epoxy resin, a photosensitive monomer such as a polyvalent acrylic monomer, a glycol ether-based solvent, and the like. It is desirable that the viscosity is adjusted to 1 to 10 Pa · s at 25 ° C. Examples of the (meth) acrylate of the novolak epoxy resin include an epoxy resin obtained by reacting glycidyl ether of phenol novolak or cresol novolak with acrylic acid, methacrylic acid, or the like.

The difunctional (meth) acrylic acid ester monomer is not particularly limited, and examples thereof include acrylic acid and methacrylic acid esters of various diols, and commercially available products of Nippon Kayaku Co., Ltd. R-604,
PM2, PM21 and the like.

The solder resist composition may contain an elastomer or an inorganic filler. When the elastomer is blended, the formed solder resist layer absorbs or relieves the stress even when stress is applied to the solder resist layer due to the flexibility and rebound resilience of the elastomer. As a result, it is possible to suppress the occurrence of cracks and peeling in the solder resist layer after the electronic component such as an IC chip is mounted on the manufacturing process of the multilayer printed wiring board or the manufactured multilayer printed wiring board. Even when cracks occur, the crack cannot grow large.

As a method of opening the solder resist layer, for example, a method of irradiating a laser beam as in the method of forming an opening for a via hole may be used.

When a photosensitive solder resist composition is used as the solder resist composition, after forming a solder resist layer, a photoresist is placed on the solder resist layer and exposed and developed. By applying, the solder resist layer can be opened.

The conductor circuit portion exposed by opening the solder resist layer is usually desirably covered with a corrosion-resistant metal such as nickel, palladium, gold, silver, and platinum. Specifically, nickel-gold, nickel-
It is desirable to form the coating layer with a metal such as silver, nickel-palladium, nickel-palladium-gold, and the like. The coating layer can be formed by, for example, plating, vapor deposition, electrodeposition, and the like, and among these, plating is preferable because of excellent uniformity of the coating layer.

In addition, a plasma treatment with oxygen, carbon tetrachloride, or the like may be performed as needed for a character printing step for forming a product recognition character or the like or for modifying a solder resist layer.

[0175]

The present invention will be described in more detail below. Example 1 A. Preparation of Resin Film for Interlayer Resin Insulation Layer Bisphenol A type epoxy resin (Epoxy equivalent 46
9. Yuka Shell Epoxy Epicoat 1001) 30
Parts by weight, 40 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 215, Epicron N-673 manufactured by Dainippon Ink and Chemicals, Inc.) Light KA-705
2) 30 parts by weight were dissolved by heating in 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha while stirring, and epoxidized polybutadiene rubber (Denalex R-45EPT manufactured by Nagase Kasei Kogyo Co., Ltd.) was added thereto.
15 parts by weight, 1.5 parts by weight of a crushed product of 2-phenyl-4,5-bis (hydroxymethyl) imidazole, 2 parts by weight of finely divided silica, and 0.5 part by weight of a silicon-based antifoaming agent are added, and an epoxy resin composition is added. Was prepared. The resulting epoxy resin composition is applied on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, and then dried at 80 to 120 ° C. for 10 minutes to form an interlayer resin. A resin film for an insulating layer was produced.

B. Preparation of Resin Composition for Filling Through Holes 100 parts by weight of a bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., Ltd., molecular weight: 310, YL983U), the average particle size of which surface is coated with a silane coupling agent is 1.6 μm, S whose maximum particle diameter is 15 μm or less
iO ₂ spherical particles (CRS 1101- manufactured by Adtech Co., Ltd.)
CE) 72 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 30 to 60 at 23 ± 1 ° C.
A Pa · s resin filler was prepared. In addition, as a curing agent, an imidazole curing agent (2E4MZ- manufactured by Shikoku Chemicals Co., Ltd.)
6.5 parts by weight (CN).

C. Production of multilayer printed wiring board (1) Glass epoxy resin or BT with a thickness of 0.8 mm
A starting material was a copper-clad laminate in which an 18 μm copper foil 32 was laminated on both sides of an insulating substrate 30 made of (bismaleimide triazine) resin (see FIG. 1A). First, the copper-clad laminate was etched into a lower-layer conductor circuit pattern, whereby lower-layer conductor circuits 34 were formed on both surfaces of the substrate (see FIG. 1B).

(2) Substrate 3 on which lower conductor circuit 34 is formed
After washing with water and drying, NaOH (10 g / l),
NaClO ₂ (40 g / l), Na ₃ PO ₄ (6 g / l)
a blackening treatment using an aqueous solution containing l) as a blackening bath (oxidizing bath);
And NaOH (10 g / l), NaBH ₄ (6 g / l
1), a roughening surface 34a was formed on the surface of the lower conductor circuit 34 (FIG. 1).
(C)).

(3) Next, the resin film for an interlayer resin insulating layer prepared in the above A was laminated by vacuum compression bonding at 0.5 MPa while heating to a temperature of 50 to 150 ° C. Was formed (see FIG. 1D). Further, a through-hole 35 having a diameter of 300 μm is formed on the substrate 30 to which the resin film layer 50α is attached by drilling.
Was formed (see FIG. 1E).

(4) Next, on the resin film layer 50α,
Through a mask in which a 1.2 mm thick through hole is formed,
Using a CO ₂ gas laser with a wavelength of 10.4 μm, a beam diameter of 4.0 mm, a top hat mode, and a pulse width of 8.0 μ
A second through-hole opening 52 having a diameter of 80 μm was formed in the resin film layer 50α under the conditions of a diameter of the through hole of the mask of 1.0 mm and a shot, and the lower interlayer resin insulation layer 50 was formed (see FIG. 2A) ).

(5) The substrate in which the via hole opening 52 was formed was immersed in a solution containing 60 g / l of permanganic acid at 80 ° C. for 10 minutes, and the wall surface of the through hole 35 was subjected to desmear treatment, and the lower interlayer was formed. By dissolving and removing the epoxy resin particles present on the surface of the resin insulating layer 50, the roughened surface 50 including the inner wall surface of the via hole opening 52 is formed.
a and 52a were formed (see FIG. 2B).

(6) Next, the substrate after the above processing is
It was immersed in a Japanese solution (manufactured by Shipley Co.) and then washed with water. Sa
Furthermore, the surface of the substrate subjected to a surface roughening treatment (roughening depth 3 μm)
By applying a palladium catalyst to the lower interlayer tree
Surface of grease insulating layer 50 (the inner wall surface of via hole opening 52)
And a catalyst nucleus is attached to the wall surface of the through hole 35.
(Not shown). That is, palladium chloride
(PbCl_Two ) And stannous chloride (SnCl) _Two ) And
Immersed in a catalyst solution to precipitate palladium metal
More catalyst was applied.

(7) Next, the substrate is immersed in an aqueous electroless copper plating solution having the following composition, and the surface of the lower interlayer resin insulating layer 50 (including the inner wall surface of the via hole opening 52) and the An electroless copper plating film 42 having a thickness of 0.6 to 3.0 μm was formed on the wall surface of the hole 35 (see FIG. 2C). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l tartaric acid 0.200 mol / l copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α'-bipyridyl 100 mg / l Polyethylene glycol (PEG) 0.10 g / l [Electroless plating conditions] 40 minutes at a liquid temperature of 34 ° C

(8) Next, a commercially available photosensitive dry film is attached to the substrate on which the electroless copper plating film 42 has been formed.
A mask was placed and exposed at 100 mJ / cm ² .
By developing with an 8% aqueous sodium carbonate solution,
A plating resist 43 having a thickness of 20 μm was provided (FIG. 2).
(D)).

(9) Subsequently, 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 plating under the following conditions. An electrolytic copper plating film 44 having a thickness of 20 μm was formed in the formation portion (see FIG. 2E). [Electroplating solution] Sulfuric acid 2.24 mol / l Copper sulfate 0.26 mol / l Additive 19.5 ml / l (Atotech Japan, Capparaside GL) [Electroplating conditions] Current density 1 A / dm ² hours 65 minutes Temperature 22 ± 2 ℃

(10) Further, the plating resist 43 is
% KOH, the electroless plated film under the plating resist 43 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and the through-hole conductor layer 3 is removed.
6, and upper layer conductor circuit (including via hole 46)
(See FIG. 3A).

(11) Next, the conductor layer 3 for a through hole
6 is formed in an etching solution to form roughened surfaces 36a and 46a on the surfaces of the through-hole conductor layer 36 and the upper conductor circuit (including the via hole 46) (FIG. 3 (B)). )reference). In addition, as an etching solution, an etching solution (Mec etch bond, manufactured by Mec Co.) comprising 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride was used.

(12) Next, after preparing the resin composition for filling through-holes described in B above, the conductor layer 36 for through-holes was formed on the wall surface within 24 hours after the preparation by the following method.
The resin composition for filling a through hole was filled in the through hole 35 in which was formed and in the via hole 46 on one side of the substrate 30. That is, first, the resin composition for filling the through-hole was pushed into the through-hole 35 using a squeegee, and then dried at 100 ° C. for 20 minutes. Next, a mask having an opening corresponding to the via hole 46 is placed on the substrate, and a resin composition for filling a through hole is filled in the via hole 46 using a squeegee. Drying was performed. Further, similarly, the resin composition for filling a through-hole was also filled in the via hole 46 on the other surface of the substrate (see FIG. 3C).

(13) Next, both surfaces of the substrate after the treatment of the above (12) were subjected to buffing to flatten the surface of the resin composition for filling the through holes exposed from the through holes 35 and the via holes 46. . Then at 150 ° C for 1 hour at 100 ° C
By performing the heat treatment for 1 hour, the resin composition for filling the through-hole was cured to form the resin filler layer 54, thereby forming the through-hole 37 (see FIG. 3D).

(14) Next, a palladium catalyst (not shown) is applied to the surface of the lower interlayer resin insulation layer 50 and the exposed surface of the resin filler layer 54 by performing the same treatment as in the above (6). did. Next, electroless plating is performed under the same conditions as in the above (7), and the surface of the lower interlayer resin insulation layer 50 is removed.
And an electroless plating film 5 on the exposed surface of the resin filler layer 54.
6 was formed (see FIG. 4A).

(15) Next, a plating resist having a thickness of 20 μm was provided on the electroless plating film 56 by the same method as in the above (8) (not shown). Furthermore, the above (9)
Electroplating was performed under the same conditions as described above to form an electroplated film 57 in the portion where the plating resist was not formed. Thereafter, the plating resist and the electroless plating film 56 existing thereunder are removed, and a cover plating layer 58 composed of the electroless plating film 56 and the electrolytic plating film 57 is formed on the through holes 37 and the via holes 46. It was formed (see FIG. 4B).

(16) Next, a roughened surface 58a was formed on the surface of the lid plating layer 58 using the etching solution (mech etch bond) used in the above (11) (see FIG. 4C). (17) Next, by repeating the above steps (3) to (11), an upper interlayer resin insulation layer 60 and an upper conductor circuit (including via holes 66) are further formed to obtain a multilayer wiring board ( (See FIG. 4D). In this step, no through hole was formed.

(18) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight was used. Oligomer for imparting properties (molecular weight: 4000) 46.6
7 parts by weight, 80% by weight dissolved in methyl ethyl ketone
Of bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd.
Trade name: Epicoat 1001) 15.0 parts by weight, imidazole hardener (manufactured by Shikoku Chemicals, trade name: 2E4MZ-C)
N) 1.6 parts by weight, a bifunctional acrylic monomer which is a photosensitive monomer (trade name: R604, manufactured by Nippon Kayaku Co., Ltd.) 4.5
Parts by weight, also polyvalent acrylic monomer (manufactured by Kyoei Chemical Co.,
A trade name: 1.5 parts by weight of DPE6A) and 0.71 parts by weight of a dispersion defoaming agent (manufactured by San Nopco, S-65) are placed in a container, stirred and mixed to prepare a mixed composition, and the mixed composition is prepared. Of benzophenone (manufactured by Kanto Chemical Co., Ltd.) as a photopolymerization initiator and 0.2 part by weight of Michler's ketone (manufactured by Kanto Chemical Co., Ltd.) as a photosensitizer at 25 ° C. A solder resist composition adjusted to 2.0 Pa · s was obtained. The viscosity was measured with a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) when the rotor No. was 60 rpm. In the case of 4, 6 rpm, the rotor No. 3
According to

(19) Next, the above-mentioned solder resist composition is applied to both sides of the multilayer wiring board in a thickness of 20 μm.
A drying treatment was performed at 70 ° C. for 20 minutes and at 70 ° C. for 30 minutes to form a solder resist composition layer 70α (see FIG. 5A). Next, a 5 mm-thick photomask on which the pattern of the solder resist opening is drawn is brought into close contact with the solder resist layer, exposed to ultraviolet light of 1000 mJ / cm ² , developed with a DMTG solution, and developed with a 200 μm solution.
An opening 71 having a diameter of m was formed. And furthermore, 80
1 hour at 100 ° C, 1 hour at 100 ° C, 1 hour at 120 ° C,
Heat treatment is performed at 50 ° C. for 3 hours to cure the solder resist layer.
A solder resist layer 70 having a thickness of 0 μm was formed (FIG. 5).
(B)). In addition, a commercially available solder resist composition can also be used as the solder resist composition.

(20) Next, the solder resist layer 70 is
The formed substrate is coated with nickel chloride (2.3 × 10^-1mol
/ L), sodium hypophosphite (2.8 x 10^-1mol
/ L), sodium citrate (1.6 x 10^-1mol /
2) in the electroless nickel plating solution having pH = 4.5 containing l)
Immerse in nickel for 0 minutes and put 5μm thick nickel
A plating layer 72 was formed. In addition, the substrate is
Potassium (7.6 × 10 ^-3mol / l), ammonium chloride
Um (1.9 × 10^-1mol / l), sodium citrate
(1.2 × 10^-1mol / l), sodium hypophosphite
(1.7 × 10 ^-1mol / l)
Immersed in the solution at 80 ° C for 7.5 minutes,
A gold plating layer 74 having a thickness of 0.03 μm is formed on the metal layer 72.
(See FIG. 5C).

(21) Then, tin-tin is placed in the opening 71 of the solder resist layer 70 on the surface of the substrate on which the IC chip is to be mounted.
Solder paste containing lead is printed and reflowed at 200 ° C. to form a solder bump (solder body) 76, and on the other surface, a solder paste is printed and a conductive connection pin 78 is attached. Thus, a multilayer printed wiring board was manufactured (see FIG. 6).

(Example 2) In Example B (Preparation of resin composition for filling through holes), instead of SiO ₂ particles,
Except for preparing the resin composition for filling through-holes using alumina particles having an average particle size of 2.0 μm and a maximum particle size of 12 μm,
A multilayer printed wiring board was manufactured in the same manner as in Example 1.
The viscosity of the prepared resin composition was 30 at 23 ± 1 ° C.
５０50 Pa · s.

(Example 3) In Example B (Preparation of resin composition for filling through hole), instead of SiO ₂ particles,
A multilayer printed wiring board was manufactured in the same manner as in Example 1, except that a resin composition for filling through holes was prepared using calcium carbonate particles having an average particle size of 1.5 μm and a maximum particle size of 16 μm. The viscosity of the prepared resin composition was 23 ± 1 ° C.
Was 25 to 60 Pa · s.

(Example 4) In Example B (Preparation of resin composition for filling through hole), instead of SiO ₂ particles,
A multilayer printed wiring board was manufactured in the same manner as in Example 1, except that a resin composition for filling through holes was prepared using potassium carbonate particles having an average particle size of 3.0 μm and a maximum particle size of 15 μm. The viscosity of the prepared resin composition was 30 to 50 Pa · s at 23 ± 1 ° C.

(Example 5) In Example B (Preparation of resin composition for filling through hole), instead of SiO ₂ particles,
A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a resin composition for filling through holes was prepared using magnesia particles having an average particle size of 1.5 μm and a maximum particle size of 12 μm. In addition, the viscosity of the prepared resin composition was 25 to 60 Pa · s at 23 ± 1 ° C.

(Comparative Example 1) In the same manner as in Example 1 except that the amount of SiO ₂ particles was changed to 5.7 parts by weight in B of Example 1 (preparation of a resin composition for filling through holes). A multilayer printed wiring board was manufactured. The viscosity of the prepared resin composition was 30 to 60 Pa · s at 23 ± 1 ° C.

Comparative Example 2 Multilayer printing was performed in the same manner as in Example 1 except that the amount of the SiO ₂ particles was changed to 132 parts by weight in B of Example 1 (preparation of a resin composition for filling through holes). A wiring board was manufactured. The viscosity of the prepared resin composition was 30 to 60 Pa · s at 23 ± 1 ° C.

For the multilayer printed wiring boards obtained in Examples 1 to 5 and Comparative Examples 1 and 2, the shape of the surface layer of the resin filler layer and the cracks in the resin filler layer under heat cycle conditions were examined. The presence or absence of occurrence, the occurrence of separation between the resin filler layer and the through-hole conductor layer or the cover plating layer, and the shape of the electroless plating film were evaluated by the following evaluation methods. The results are shown in Table 1.

(1) Shape of Surface Layer of Resin Filler Layer A multilayer printed wiring board is vertically cut so as to include through holes.
And observe the shape of the surface of the resin filler layer with a microscope
And evaluated according to the following evaluation criteria.Evaluation criteria  ：: The surface portion of the resin filler layer is polished flat. ×: The surface portion of the resin filler layer is caused by the detachment of the inorganic particles.
Depressions are not formed or not sufficiently polished
Is not flat.

(2) Shape of Electroless Plating Film Similar to the above (1), the multilayer printed wiring board is formed with through holes.
By cutting it vertically so that it contains
The shape of the electroless plating film was evaluated. Evaluation criteria
Is as follows.Evaluation criteria  ：: An electroless plating film having a uniform thickness was formed. ×: The part where the thickness of the electroless plating film is not uniform or the electroless plating film
A portion where no plating was formed was observed.

(3) The occurrence of cracks in the resin filler layer
Presence Same as above (1)
By cutting it vertically so that it contains
To determine whether cracks have occurred in the resin filler layer.
Valued. The evaluation criteria are as follows.Evaluation criteria  ：: No crack was observed. Δ: Product quality, although some cracks occurred
Was not enough to affect. ×: A large crack has occurred and the product is not used.
I couldn't do it.

(4) Resin filler layer and conductor for through hole
Whether or not peeling has occurred between the layer and the cover plating layer.
By cutting it vertically so that it contains
Layer, resin filler layer, conductor layer for through hole and lid plating layer
Then, it was evaluated whether or not peeling occurred. What
The evaluation criteria are as follows.Evaluation criteria  ：: No peeling was observed. Δ: Although the peeling occurred slightly, the quality of the product was affected.
It was not enough to make a difference. ×: Largely peeled off and can be used as a product
I didn't come.

The evaluations of the above (3) and (4) are as follows.
The test was performed before the heat cycle test, after the heat cycle was completed 1000 times, and after the heat cycle test was completed 2000 times. In addition, the heat cycle test was performed by maintaining the multilayer printed wiring board at 125 ° C. for 3 minutes and then maintaining the multilayer printed wiring board at −55 ° C. for 3 minutes in one cycle.

[0209]

[Table 1]

As shown in Table 1, in the multilayer printed wiring boards of Examples 1 to 5, the surface portion of the resin filler layer was polished flat, and the surface portion of the resin filler layer was not polished. An electroless plating film having a uniform thickness was formed. Further, even under the heat cycle condition, no crack was generated in the resin filler layer, and no peeling was generated between the resin filler layer and the conductor layer for through holes.

On the other hand, in the multilayer printed wiring board of Comparative Example 1, the surface of the resin filler layer was polished flat, and the surface of the resin filler layer was formed by electroless plating having a uniform thickness. A film had been formed. However, under the heat cycle conditions, cracks occurred in the resin filler layer, and peeling occurred between the resin filler layer and the conductor layer for through holes. In addition, in the multilayer printed wiring board of Comparative Example 2, the surface layer portion of the resin filler layer was not polished flat, and a portion that was insufficiently polished and a concave portion caused by falling off of inorganic particles were observed. In addition, the formed electroless plating film was non-uniform in thickness, and a portion where the electroless plating film was not deposited was observed. For this reason, peeling has occurred between the resin filler layer and the conductor layer for through holes.

[0212]

As described above, in the multilayer printed wiring board of the present invention, since the resin filler layer containing 10 to 50% by weight of inorganic particles is formed in the through hole, the resin filler layer is formed. There is no significant difference in thermal expansion coefficient between the resin filler layer and the substrate, and the resin filler layer and the conductor layer covering the surface layer have excellent adhesion, so that even under heat cycle conditions, No cracks occur in the resin filler layer, and no separation occurs between the resin filler layer and the conductor layer, and the connection reliability is excellent. Further, on the through hole of the multilayer printed wiring board, a conductor layer covering a surface portion of the resin filler layer is formed as a part of a conductor circuit,
Since the via hole is formed on the conductor layer, the wiring length in the multilayer printed wiring board is short, and the signal transmission time can be shortened, so that it is possible to cope with an increase in the speed of the IC chip.

In the method for manufacturing a multilayer printed wiring board according to the present invention, the resin composition for filling a through-hole containing inorganic particles is filled in the through-hole, and then the resin composition for filling a through-hole is exposed from the through-hole. Since the surface is polished, a through hole having a flat surface layer can be formed. Therefore, when an interlayer resin insulating layer is further formed by lamination, a swell or the like does not occur in the formed interlayer resin insulating layer, and a multilayer printed wiring board having excellent reliability can be manufactured. Further, in the above production method, since the content ratio of the inorganic particles of the resin composition for filling through holes is in the above range,
The surface of the resin composition for filling a through-hole exposed from the through-hole can be easily flattened.

In the method for manufacturing a multilayer printed wiring board, a resin filler layer and a lid plating layer are formed. As described above, the resin filler layer contains 10 to 50% by weight of inorganic particles. Therefore, it is suitable for forming a lid plating layer, and the resin filler layer and the lid plating layer formed by the above manufacturing method have excellent adhesion.

In the above manufacturing method, the conductor layer covering the surface portion of the resin filler layer is formed as a part of the conductor circuit, and the via hole is formed on the conductor layer. It is possible to manufacture a multilayer printed wiring board having a short length and corresponding to an increase in the speed of an IC chip. Furthermore, the multilayer printed wiring board obtained by the production method of the present invention is less likely to cause cracks in the resin filler layer even under heat cycle conditions, and peeling between the resin filler layer and the lid plating layer is also prevented. Since it hardly occurs, the connection reliability is excellent.

[Brief description of the drawings]

FIGS. 1A to 1E are cross-sectional views showing a part of steps of a method for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 2A to 2E are cross-sectional views showing a part of steps of a method for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 3A to 3D are cross-sectional views illustrating some of the steps of the method for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 4A to 4D are cross-sectional views illustrating some of the steps of the method for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 5A to 5C are cross-sectional views illustrating some of the steps of the method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 6 is a cross-sectional view showing one embodiment of the multilayer printed wiring board of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 30 substrate 32 copper foil 34 lower conductive circuit 35 through hole 52 via hole opening 42 electroless plating film 43 plating resist 44 electrolytic plating film 50 lower interlayer resin insulating layer 54 resin filler layer 58 lid plating layer 60 upper interlayer resin insulating layer 70 Solder resist layer 76 Solder bump 78 Conductive pin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E314 AA32 AA42 BB06 FF05 FF08 FF19 GG12 5E343 AA02 AA07 AA17 BB24 BB67 CC73 DD33 DD43 DD76 EE01 EE13 GG02 5E346 AA06 AA35 AA43 CC08 CC09 CC32 CC55 DD12 DD25 DD32 DD25 DD33 GG15 GG37 HH11

Claims (7)

[Claims] 1. A conductive circuit and an interlayer resin insulating layer are sequentially laminated on both surfaces of a substrate, and the substrate and the conductive circuit sandwiching the interlayer resin insulating layer are connected via a through hole.
A multilayer printed wiring board in which conductor circuits sandwiching the interlayer resin insulation layer are connected via via holes,
In the through hole, a resin filler layer obtained by curing a resin filler containing an epoxy resin, a curing agent, and inorganic particles is formed, and the content ratio of the inorganic particles in the resin filler layer is: A conductor layer covering a surface layer of the resin filler layer is formed as a part of a conductor circuit on the through hole, and a via hole is formed on the conductor layer. A multilayer printed wiring board. 2. The method according to claim 1, wherein the inorganic particles include an aluminum compound,
The multilayer printed wiring board according to claim 1, comprising at least one selected from the group consisting of a calcium compound, a potassium compound, a magnesium compound and a silicon compound. 3. The shape of the inorganic particles is spherical, elliptical, crushed, or polyhedral.
2. The multilayer printed wiring board according to item 1. 4. The multilayer printed wiring board according to claim 1, wherein a roughened surface is formed on at least a part of a surface of the conductor layer forming the through hole. 5. A method for producing a multilayer printed wiring board, comprising at least the following steps (A) to (I). (A) a through-hole forming step of forming a through-hole in a substrate having a lower conductor circuit and a lower interlayer resin insulating layer formed on both surfaces thereof; and (B) a wall surface of the through-hole and the lower interlayer resin insulating layer. A conductor layer forming step of forming a conductor layer on a part of the surface,
(C) for filling a through-hole containing an epoxy resin, a curing agent and inorganic particles in the through-hole having a conductor layer formed on its wall surface, wherein the content ratio of the inorganic particles after curing is 10 to 50% by weight; A resin filling step of filling the resin composition, (D) a drying step of drying the resin composition for filling the through hole, and (E) a polishing treatment on the surface of the resin composition for filling the through hole exposed from the through hole. (F) a through-hole forming step of curing the resin composition for filling a through-hole and forming a through-hole having a resin filler layer formed therein;
(G) a cover plating layer forming step of forming a conductor layer covering a surface portion of the resin filler layer as a part of a conductor circuit; (H) a via on a lower interlayer resin insulation layer having a conductor layer formed on its surface; An upper interlayer resin insulating layer forming step of laminating and forming an upper interlayer resin insulating layer having a hole opening; and (I) a via hole forming step of forming a conductor layer in the via hole opening. 6. The method for manufacturing a multilayer printed wiring board according to claim 5, wherein the polishing step is a step of performing at least one buff polishing process. 7. In the conductor layer forming step, after forming the conductor layer, at least a part of the surface of the conductor layer is
The method for manufacturing a multilayer printed wiring board according to claim 5, wherein a roughened surface is formed.