JP2002026524A - Multilayer interconnection board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer interconnection board and its manufacturing method having superior productivity and connection reliability. SOLUTION: This multilayer interconnection board has a core wiring board where substrate-wiring layers that are mutually and electrically connected onto both the surfaces of an insulating board are formed, an insulating layer that is laminated at least onto one surface of the core-wiring board, a wiring layer that is formed on the insulating layer, and an interlayer short-circuiting part that electrically connects the wiring layer to the substrate-wiring layer and passes through the insulating layer in its thickness direction for extension. In this case, the interlayer short-circuiting part is composed by a conductive material containing a conductive fine particle in a macromolecular substance, and the conductive material is formed by electrodeposition treatment in electrolytic deposition liquid where the conductive fine particle and an organic particle consisting of at least one of a polymerization compound and a polymer are dispersed in an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, with the demand for higher functionality and smaller size of electronic equipment, electronic parts having a high degree of integration and a large number of electrodes have been used. Is required to be mounted at a high density.
Therefore, as a wiring board for electronic parts or a wiring board for mounting electronic parts, a single-sided printed wiring board in which a wiring layer is formed on only one side of an insulating substrate, or a double-sided board in which a wiring layer is formed on both sides of a substrate Instead of a printed wiring board, a multilayer printed wiring board in which insulating layers and wiring layers are alternately laminated on one or both surfaces of a substrate is used.

Conventionally, as a method of manufacturing a multilayer printed wiring board, a plurality of core wiring boards having wiring layers electrically connected to each other on both sides of an insulating layer, and a thermosetting resin prepreg sheet are used. A method in which a plurality of core wiring boards are integrally laminated via an insulating layer by alternately stacking and thermocompression bonding (hereinafter, referred to as “lamination pressing method”) has been the mainstream. However, in this lamination press method,
In order to make an electrical connection between the wiring layers in the adjacent core wiring board, it is impossible to form interlayer short-circuit portions (buried vias and blind vias) extending only through the insulating layer existing between the wiring layers in the thickness direction. In addition, it is necessary to form an interlayer short-circuit portion (through hole) that extends through the entire multilayer wiring board in the thickness direction, and therefore, it is difficult to form a high-density wiring layer.

For these reasons, recently, as a method of manufacturing a multilayer printed wiring board having a high-density wiring layer, a build-up method in which an insulating layer and a wiring layer are sequentially formed one by one on a core wiring board has been recently adopted. Is attracting attention. According to this build-up method, electrical connection between the wiring layers can be made by a short-circuit portion extending through only the insulating layer existing between the wiring layers in the thickness direction, so that a high-density wiring layer is formed. It is possible. More specifically, in this build-up method, an insulating layer having a through-hole corresponding to an interlayer short-circuit portion (via) to be formed is formed on the surface of the core wiring board, and then the through-hole in the insulating layer is formed. A conductor constituting an interlayer short-circuit portion is formed therein, a wiring layer is formed on the surface of the insulating layer, and this process is repeated a predetermined number of times, thereby obtaining a target multilayer wiring board.

In the above, as a method for forming an insulating layer having a through hole on the surface of a core substrate, a liquid radiation curable resin material is applied to the surface of the core substrate, and then the coating film is exposed to light and developed. A method of forming an insulating layer having a through hole corresponding to a target short-circuited portion (via hole) by performing a process, a method of applying a liquid thermosetting resin material on the surface of a core substrate or forming a sheet. A method of forming an insulating layer by arranging a thermosetting resin material of the above and performing a heat treatment, and irradiating the insulating layer with a laser to form a through hole corresponding to a target interlayer short-circuit portion. It has been known. In addition, as a method of forming a conductor in the through hole of the insulating layer, by an electroless plating method,
A method of forming a metal thin film by depositing a metal on the inner surface of the through hole of the insulating layer to form a metal thin film, using the thin metal film as an electrode, and depositing a metal by electrolytic plating to form a conductor having a metal layer of a required thickness; A method in which a metal is deposited on the inner surface of a through hole of an insulating layer by an electroless plating method to form a conductor made of a metal layer having a required thickness, and a conductive powder is dispersed in a liquid thermosetting resin material. The conductive paste composition is filled into the through-holes of the insulating layer by a printing method such as screen printing, and the conductive paste composition is cured to disperse the conductive powder in the thermosetting resin. There is known a method of forming a conductor formed by such a method.

Thus, in such a build-up method, every time an insulating layer is formed, it is necessary to form an interlayer short-circuit portion penetrating the insulating layer in the thickness direction.
However, when the interlayer short-circuit portion is formed by the plating method, it takes a considerably long time to form a metal layer having a required thickness because the deposition rate of metal by plating is low. There is a problem that the property cannot be obtained. On the other hand, when an interlayer short-circuit portion is formed with the conductive paste composition, the conductive paste composition generally has a high viscosity (for example, 100 Pa · s at 25 ° C.), so that the diameter of the through hole of the insulating layer is large. Is small, it is difficult to reliably fill the through-hole with the conductive paste composition, and therefore, there is a problem that a multilayer wiring board having high connection reliability cannot be obtained.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object is to provide a multilayer wiring board having high productivity and high connection reliability. Another object of the present invention is to provide a method capable of manufacturing a multilayer wiring board having high productivity and high connection reliability.

[0008]

According to the present invention, there is provided a multilayer wiring board comprising:
A core wiring board in which board wiring layers electrically connected to each other are formed on both surfaces of an insulating substrate; an insulating layer laminated on at least one surface of the core wiring board; and wiring formed on the insulating layer A multi-layer wiring board having a layer and an interlayer short-circuit portion extending through the insulating layer in a thickness direction thereof for electrically connecting the wiring layer to the substrate wiring layer, wherein the interlayer short-circuit portion is high. A conductive material comprising conductive fine particles contained in a molecular substance. The conductive material is obtained by dispersing conductive fine particles and organic particles comprising at least one of a polymerizable compound and a polymer in an aqueous medium. It is characterized by being formed by performing an electrodeposition process in the liquid.

In the multilayer wiring board of the present invention, the core wiring board electrically connects board wiring layers formed on both surfaces of the insulating board to each other, and penetrates the insulating board in a thickness direction thereof. The substrate short-circuited portion extends, the substrate short-circuited portion is made of a conductive material containing conductive fine particles in a polymer substance, the conductive material, the conductive fine particles and a polymerizable compound in an aqueous medium and It is preferably formed by performing an electrodeposition treatment in an electrodeposition solution in which organic particles comprising at least one of polymers are dispersed. Further, it is preferable that the ratio of the conductive fine particles in the conductor constituting the interlayer short-circuit portion and / or the substrate short-circuit portion is 40 to 80% by volume fraction.

The method of manufacturing a multilayer wiring board according to the present invention comprises the steps of: forming an insulating substrate; a substrate wiring layer formed on one surface of the insulating substrate; and a substrate wiring layer formed on the other surface of the insulating substrate. A core wiring board material made of an electrically connected metal layer is prepared, and a through hole formed on one surface of the core wiring board material corresponding to an interlayer short-circuit portion to be formed on the board wiring layer. Forming an insulating layer having, the substrate wiring portion of the core wiring substrate material on which the insulating layer is formed as a deposition electrode,
By performing electrodeposition in an electrodeposition solution in which conductive fine particles and organic particles comprising at least one of a polymerizable compound and a polymer are dispersed in an aqueous medium, an interlayer short-circuit portion is formed in a through hole of the insulating layer. And a step of forming a conductor constituting

In the method for manufacturing a multilayer wiring board of the present invention, a substrate forming material having an insulating substrate and a metal layer formed on at least the other surface of the insulating substrate is prepared. Forming a through-hole penetrating the conductive substrate in the thickness direction thereof, and using a metal layer in the substrate forming material as an electrode for deposition, in an aqueous medium, conductive fine particles and organic particles comprising at least one of a polymerizable compound and a polymer. Is formed in the electrodeposition liquid in which the conductive material constituting the substrate short-circuit portion is formed in the through-hole of the insulating substrate, and then the substrate wiring portion is formed on one surface of the insulating substrate. It is preferable that the core wiring board material is formed by forming. Further, the ratio of the conductive fine particles to the organic particles in the electrodeposition liquid is 80:20 by volume ratio.
４０40: 60 is preferred.

[0012]

In an electrodeposition solution in which conductive fine particles and organic particles are dispersed, an electrode short-circuit portion is formed in a short time by performing electrodeposition using the substrate wiring layer as a deposition electrode. High productivity is obtained in the manufacture of boards. As the electrodeposition liquid, it is possible to easily prepare a low-viscosity one, and by using such an electrodeposition liquid, even if the diameter of the through-hole formed in the insulating layer is small,
As a result of sufficiently penetrating into the through hole, an intended interlayer short-circuit portion can be reliably formed, and a multilayer wiring board having high connection reliability can be obtained.

[0013]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory cross-sectional view showing a configuration of an example of a multilayer wiring board according to the present invention. This multilayer wiring board has a core wiring substrate 10, in which a first substrate wiring layer 12 is formed on an upper surface of an insulating substrate 11, and a lower surface of the insulating substrate 11 is formed on the lower surface of the insulating substrate 11.
A second substrate wiring layer 13 is formed, and the first substrate wiring layer 12 and the second substrate wiring layer 13
1 are electrically connected to each other by a substrate short-circuit portion 14 extending through the thickness direction. Core wiring board 10
An upper insulating layer 20 is formed on the upper surface of the substrate, and an upper wiring layer 21 is formed on the upper surface of the upper insulating layer 20,
The upper surface wiring layer 21 is electrically connected to the first substrate wiring layer 12 by an interlayer short-circuit portion 22 extending through the upper insulating layer 20 in the thickness direction. Further, on the upper surface of the upper insulating layer 20 including the upper wiring layer 21, a solder resist layer 25 having an opening 26 exposing a component connection land in the upper wiring layer 21 is provided. On the other hand, a lower insulating layer 30 is formed on the lower surface of the core wiring substrate 10, and the lower wiring layer 3 is formed on the lower surface of the lower insulating layer 30.
The lower wiring layer 31 is formed by an interlayer short-circuit portion 32 extending through the lower insulating layer 30 in the thickness direction.
Is electrically connected to the second substrate wiring layer 13. Further, on the upper surface of the lower insulating layer 30 including the lower wiring layer 31, a solder resist layer 35 having an opening 36 for exposing the component connection land in the lower wiring layer 31 is provided.

Insulating substrate 11 in core wiring substrate 10
It is preferable to use an insulating resin material having high heat resistance as a material for forming the resin. Specific examples thereof include glass fiber reinforced epoxy resin, glass fiber reinforced polyimide resin, glass fiber reinforced phenol resin, and glass fiber. Reinforced bismaleimide triazine resin, polyimide resin,
Examples thereof include a polyamide resin and a polyester resin.
The substrate short-circuit portion 14 may be any of various structures conventionally used for printed wiring boards, for example, a cylindrical metal deposit formed by electroless plating and electrolytic plating, or a conductive material in a thermosetting resin material. A conductive paste material in which conductive particles are dispersed may be used, but the material constituting the interlayer short-circuit portion 22 and the interlayer short-circuit portion 32 described later, that is, the conductive fine particles may be used in an aqueous medium. It is preferable to use a conductive material formed by performing an electrodeposition treatment in an electrodeposition solution in which organic particles comprising at least one of a polymerizable compound and a polymer are dispersed.

As the material constituting the upper insulating layer 20 and the lower insulating layer 30, various thermosetting resin materials or radiation curable resin materials conventionally used for printed wiring boards can be used.

The interlayer short-circuit portions 22 and 32 formed on the upper insulating layer 20 and the lower insulating layer 30 are made of a conductor containing conductive fine particles in a polymer substance. It is formed by performing an electrodeposition treatment in a specific electrodeposition liquid. The specific electrodeposition liquid for forming the interlayer short-circuit portions 22 and 32 is obtained by dispersing conductive fine particles and organic particles comprising at least one of a polymerizable compound and a polymer in an aqueous medium. . Hereinafter, the electrodeposition liquid used in the present invention will be described.

(1) Conductive fine particles: The material constituting the conductive fine particles used in the electrodeposition liquid is not particularly limited as long as it shows conductivity, but a stable conductivity can be obtained for a long period of time. And those which are not easily oxidized are preferable. Specific examples of such conductive materials include gold,
Silver, copper, aluminum, zinc, nickel, palladium,
Examples include metals selected from platinum, cobalt, rhodium, iridium, iron, ruthenium, osmium, chromium, tungsten, tantalum, titanium, bismuth, lead, boron, silicon, tin and barium, and alloys thereof. Further, as the conductive fine particles, two or more kinds of fine particles having different materials may be used in combination. Further, the conductive fine particles are preferably made of a material having a volume resistivity of 10 ⁻⁵ Ω · cm or less, more preferably 7 × 10 ⁻⁶ Ω · cm or less.

The conductive fine particles preferably have a number average particle diameter of 1 μm or less, more preferably 0.5 μm or less, particularly preferably 0.3 μm or less. When the number average particle size exceeds 1 μm, the conductive particles tend to settle in the electrodeposition solution, and the storage stability of the electrodeposition solution tends to be low.
On the other hand, the lower limit of the number average particle diameter of the conductive fine particles is not particularly limited, but is usually 0.02 μm or more. In addition, in this specification, "particle diameter" shall mean a primary particle diameter. As such conductive fine particles, metal fine particles manufactured by a chemical vapor deposition method (hereinafter, referred to as a “CVD method”), an electrolytic method, a reduction method, or the like are preferable because the fine particles can be easily manufactured. used.

(2) Organic particles: The organic particles used in the electrodeposition solution are composed of at least one of a polymerizable compound and a polymer. Here, the “polymerizable compound” refers to a compound having a polymerizable group, and includes a polymer, a polymerizable oligomer, a monomer, and the like as a precursor before being completely cured. On the other hand, “polymer” refers to a compound in which a polymerization reaction has been substantially completed. However, a material which can be crosslinked after electrodeposition by heating, moisture, or the like may be used.
The organic particles only need to be capable of being electrodeposited. Specifically, it is preferable that the organic particles have a charge on the surface, and the surface charge may be an anionic type or a cationic type. In addition, when the material of the conductive fine particles is copper, the surface charge of the organic particles is preferably a cationic type in that the storage stability of the electrodeposition solution is good.

The organic particles preferably contain one or more resin components selected from acrylic resins, epoxy resins, polyester resins, and polyimide resins. Further, other components may be contained in addition to these resin components, and further, these resin components and other components may be chemically bonded to each other. Further, as the organic particles, it is particularly preferable to use a material containing a polyimide-based resin as a main component, since it is easy to form a conductor having excellent mechanical properties, chemical properties, and electrical properties. Here, the “polyimide resin” refers to a polyimide resin or a polymer (eg, polyamic acid or the like) as a precursor that can be cured by heating after electrodeposition, a monomer used for forming the polyimide resin, and other components. A copolymer resin as a monomer or a polymer as a precursor thereof, a polyimide resin or a reaction product of a polymer as a precursor thereof and another compound, and a monomer used to form a polyimide resin, The meaning includes oligomers and the like, and the same applies to other resins.

Such organic particles are usually prepared as an aqueous emulsion in which the organic particles are dispersed in an aqueous medium. Hereinafter, an aqueous emulsion of organic particles mainly composed of an acrylic resin (hereinafter, referred to as "acrylic resin emulsion"), an aqueous emulsion of organic particles mainly composed of an epoxy resin (hereinafter, referred to as "epoxy resin emulsion"), An aqueous emulsion of organic particles mainly composed of a polyester resin (hereinafter, referred to as "polyester resin emulsion") and an aqueous emulsion of organic particles mainly composed of a polyimide resin (hereinafter, referred to as "polyimide resin emulsion"). The manufacturing method will be described.

(I) Method for producing acrylic resin emulsion: The method for producing the acrylic resin emulsion is not particularly limited. For example, a conventional emulsion polymerization method or polymerization in an organic solvent such as alcohol is used. A method in which the reaction solution is added to water while stirring to disperse the resin can be used. As the monomer, one or more monomers selected from general acrylic monomers and / or methacrylic monomers may be used. At this time, in order to make the organic particles electrodepositable, a monomer having a cationic group or an anionic group is usually copolymerized. The copolymerization ratio is preferably from 5 to 80% by weight, particularly preferably from 10 to 50% by weight, based on all monomers used.

(Ii) Production method of the epoxy resin emulsion: The production method of the epoxy resin emulsion is not particularly limited, and conventionally known methods, for example, JP-A-9-235495 and JP-A-9-208865. For example, a method described in Japanese Patent Application Laid-Open Publication No. H10-208 can be used.

(Iii) Method for producing polyester resin emulsion: The method for producing the polyester resin emulsion is not particularly limited, and conventionally known methods, for example, JP-A-57-10663 and JP-A-57-10663 −70
153 and JP-A-58-174421.

(Iv) Method for producing polyimide resin emulsion: The method for producing the polyimide resin emulsion is as follows.
Although not particularly limited, preferred polyimide resin emulsions and methods for producing the same include the following. (A) A polyimide resin emulsion comprising composite particles of (A) an organic solvent-soluble polyimide and (B) a hydrophilic polymer. This polyimide resin emulsion can be preferably produced, for example, by the method described in JP-A-11-49951. (B) A polyimide resin emulsion comprising particles containing composite particles of (C) a polyamic acid and (D) a hydrophobic compound. This polyimide resin emulsion can be preferably produced, for example, by the method described in JP-A-11-60947. These polyimide-based resin emulsions have excellent storage stability as an aqueous dispersion and have the inherent heat resistance, electrical insulation, mechanical properties, chemical resistance, etc. of polyimide by electrodepositing the particles in this emulsion. This is preferable because a held electrodeposition film can be formed.

The polyimide resin emulsion (a) and the method for producing the same will be described in more detail.
The method for synthesizing “(A) an organic solvent-soluble polyimide” is not particularly limited. For example, a tetracarboxylic dianhydride and a diamine compound are mixed and polycondensed in an organic polar solvent. After preparing a polyamic acid, a method of synthesizing a polyimide by subjecting the polyamic acid to a dehydration ring-closing reaction by a heat imidation method or a chemical imidization method can be used. In addition, a polyimide having a block structure can be synthesized by performing polycondensation of a tetracarboxylic dianhydride and a diamine compound in multiple stages. The organic solvent-soluble polyimide preferably has, for example, one or more reactive groups (a) such as a carboxyl group, an amino group, a hydroxyl group, a sulfonic acid group, an amide group, an epoxy group, and an isocyanate group. As a method for synthesizing a polyimide having a reactive group (a), for example, a reactive raw material such as a carboxylic dianhydride, a diamine compound, a carboxylic monoanhydride, or a monoamine compound used for the synthesis of polyamic acid may be used. Examples of the method include using a compound having the group (a) and leaving the reactive group (a) after the dehydration ring closure reaction.

The “(B) hydrophilic polymer” has, for example, at least one kind of hydrophilic group such as an amino group, a carboxyl group, a hydroxyl group, a sulfonic acid group and an amide group.
The solubility at 0 ° C. is usually 0.01 g / 100 g or more, preferably 0.05 g / 100 g or more. In addition to the hydrophilic group, the reactive group (a) in the component (A)
It is preferable to have at least one type of reactive group (b) that can react with. As such a reactive group (b), for example,
In addition to an epoxy group, an isocyanate group, and a carboxyl group, groups similar to the above-mentioned hydrophilic groups can be exemplified.
Such a hydrophilic polymer is obtained by homopolymerizing or copolymerizing a monovinyl monomer having a hydrophilic group and / or a reactive group (b), or combining these monovinyl monomers with other monomers. It can be obtained by copolymerization.

This (A) organic solvent-soluble polyimide and (B) a hydrophilic polymer are combined with a combination in which the reactive group (a) and the reactive group (b) in the hydrophilic polymer have appropriate reactivity. It is selected so that the polyimide and the hydrophilic polymer are mixed in a solution state in, for example, an organic solvent, and, if necessary, are reacted while heating,
Thereafter, by mixing the reaction solution and the aqueous medium and removing at least a part of the organic solvent as necessary,
With the polyimide and the hydrophilic polymer bonded to each other, a polyimide resin emulsion having composite particles contained in the same particle can be obtained.

Next, the polyimide resin emulsion (b) and the method for producing the same will be described in more detail. The method for synthesizing “(C) polyamic acid”, which is a precursor of polyimide, is not particularly limited. For example, a polyamic acid is obtained by a polycondensation reaction between a tetracarboxylic dianhydride and a diamine compound in an organic polar solvent. An acid can be prepared. In addition, a polyamic acid having a block structure can be synthesized by performing a polycondensation reaction between a tetracarboxylic dianhydride and a diamine compound in multiple stages. The polyamic acid may be partially imidized by dehydration and ring closure.

On the other hand, the "(D) hydrophobic compound" is a compound having a group capable of reacting with at least an amic acid group in the polyamic acid (hereinafter referred to as "reactive group"). Examples of the reactive group include an epoxy group, an isocyanato group, a carbodiimide group, a hydroxyl group, a mercapto group, a halogen group, an alkylsulfonyl group, an arylsulfonyl group, a diazo group, and a carbonyl group. One or more of these reactive groups can be present in the hydrophobic compound. The term “hydrophobic” means that the solubility in water at 20 ° C. is generally less than 0.05 g / 100 g, preferably less than 0.01 / 100 g, and more preferably less than 0.005 g / 100 g. .

Examples of such a hydrophobic compound include epoxidized polybutadiene, bisphenol A type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, biphenyl type epoxy resin, glycidyl ester type epoxy resin, allyl glycidyl ether,
Glycidyl (meth) acrylate, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N,
N ', N',-tetraglycidyl-m-xylenediamine, tolylenediisocyanate, dicyclohexylcarbodiimide, polycarbodiimide, cholesterol, benzyl alcohol p-toluenesulfonic acid ester, ethyl chloroacetate, triazinetrithiol, diazomethane, diacetone (meth) One or more selected from acrylamide and the like can be used.

The (C) polyamic acid and the (D) hydrophobic compound are mixed and reacted in, for example, an organic solvent in a solution state. Thereafter, the reaction solution is mixed with an aqueous medium, and By removing at least a part of the organic solvent, a polyimide resin emulsion having composite particles containing the polyamic acid and the hydrophobic compound in the same particle can be obtained.

The tetracarboxylic dianhydride used in the methods (a) and (b) is not particularly limited, and specific examples thereof include butanetetracarboxylic dianhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-
Tricarboxycyclopentylacetic acid dianhydride, 1,3
3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,
Aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride such as 2-c] -furan-1,3-dione; pyromellitic dianhydride, 3,3 ′, 4,4′-
Benzophenone tetracarboxylic dianhydride, 3,3 ',
Aromatic tetracarboxylic dianhydrides such as 4,4'-biphenylsulfone tetracarboxylic dianhydride; and the like. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

The diamine compound used in the methods (a) and (b) is not particularly limited, and specific examples thereof include p-phenylenediamine, 4,4'-diaminodiphenylmethane, Aromatic diamines such as 1,2-bis [4- (4-aminophenoxy) phenyl] propane; 1,1-methaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, 4,4′-methylenebis ( Cyclohexylamine)
Aliphatic diamines or alicyclic diamines;
-Diaminopyridine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 2,4-diamino-
5-phenylthiazole, bis (4-aminophenyl)
Diamines having two primary amino groups and a nitrogen atom other than the primary amino groups in the molecule, such as phenylamine; monosubstituted phenylenediamines; diaminoorganosiloxane; These diamine compounds can be used alone or in combination of two or more.

(3) Electrodeposition liquid: The electrodeposition liquid used in the present invention is obtained by dispersing the above conductive fine particles and organic particles in an aqueous medium. As used herein, the term "aqueous medium" means a medium containing water, and the content of water in the aqueous medium is usually 2% by weight or more, preferably 10% by weight or more. When the content of water is less than 2% by weight, it is not preferable because it becomes difficult to use it as an electrodeposition liquid. On the other hand, when the content of water in the aqueous medium is excessive, the dispersion stability of the conductive fine particles and the like is reduced. Therefore, the proportion of water is preferably 50% by weight or less, more preferably 40% by weight or less. And particularly preferably 2
0% by weight or less. As other media used together with water as necessary, for example, the aprotic polar solvent used in the production of the above-mentioned polyamic acid or polyimide, esters, ketones, phenols, alcohols, amines and the like Can be mentioned. Among these, from the viewpoint of the dispersion stability of the metal fine particles as the conductive fine particles, 10 to 90% by weight, particularly 20 to 70% by weight, of one or more alcohols having 1 to 10 carbon atoms is used. % Is preferred. Also,
This aqueous medium contains amines such as monoethanolamine and diethanolamine in an amount of 0.01 to 5% by weight, especially 0.1 to 5% by weight.
Preferably, the content of the fine particles is in the range of 1 to 1% by weight, whereby the dispersion stability of the conductive fine particles is further improved.

The ratio between the conductive fine particles and the organic particles contained in the electrodeposition liquid is preferably in the range of 80:20 to 40:60 by volume, more preferably 80:20 to 6: 6.
The range is 0:40. When the ratio of the conductive fine particles is less than 40% by volume of the total of the conductive fine particles and the organic particles, the obtained conductor has a large volume resistivity and has a low practicality as an interlayer short-circuit portion. It may be. On the other hand, if the proportion of the conductive fine particles exceeds 80% by volume of the total of the conductive fine particles and the organic particles, the obtained conductor tends to have low shape retention and adhesion to the insulating layer. Cracks may occur in the body. The pH of the electrodeposition solution is 6-12.
And more preferably 8 to 10
It is. The solid content concentration in the electrodeposition solution is 1 to 50.
%, More preferably 5 to 30% by weight.
% By weight. The viscosity of the electrodeposition solution at 20 ° C. is 1
It is preferable that it is 100 mPa * s. Electrodeposition liquid p
If the concentration of H, the solid content or the viscosity is out of the above range, the dispersibility of the particles and the like may be reduced, resulting in low storage stability, or a sufficient electrodeposition rate may not be obtained, and the productivity may be reduced. In some cases, the workability at the time of use or use may be reduced, or it may be difficult to electrodeposit a finely shaped portion in the through hole.

Such an electrodeposition solution is preferably prepared by mixing a conductive fine particle dispersion in which the conductive fine particles are dispersed in an appropriate organic solvent, and an aqueous emulsion of the organic particles. Examples of the organic solvent used in the above-mentioned “conductive fine particle dispersion” include alcohols composed of one or more alcohols having 1 to 10 carbon atoms from the viewpoints of dispersion stability and solubility in an aqueous emulsion medium. Solvents are preferred, and among them, ethyl alcohol, isopropyl alcohol or a mixed solvent thereof is particularly preferred. Examples of a method for dispersing the conductive fine particles in an organic solvent include a method using a homomixer, a high-pressure homogenizer, an ultrasonic mixer, and the like, and a method using a combination thereof. The conductive fine particle dispersion preferably contains conductive fine particles at a ratio of 3 to 40% by weight, more preferably 5 to 40% by weight.
３０30% by weight.

In the electrodeposition solution used in the present invention, in addition to the conductive fine particles and the organic particles, an organosilane represented by the following general formula (1), and a part of the hydrolyzable group of the organosilane Alternatively, at least one compound selected from a hydrolyzate in which all of the hydrolyzate is hydrolyzed and a partial condensate in which the hydrolyzate is partially dehydrated (hereinafter, these are collectively referred to as “specific organosilane compounds”). ) May be contained. The conductor formed by such an electrodeposition liquid, particularly when heat-cured after electrodeposition, is crosslinked by a specific organosilane-based compound in the conductor, resulting in mechanical and chemical properties. It will be excellent.

[0039]

Embedded image General formula (1) (R ¹ ) _n Si (OR ² ) _4-n

[In the general formula (1), R ¹ represents a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms and 1 to 6 carbon atoms. And n is an integer of 1 or 2. R ¹ and R ² may be the same or different. ]

In the above general formula (1), as the organic group having 1 to 8 carbon atoms for R ¹ , a linear or branched alkyl group, a halogen-substituted alkyl group, a vinyl group, a phenyl group and a 3,4 -An epoxycyclohexylethyl group and the like. R ¹ may have a carbonyl group. R ¹ is preferably an alkyl group having 1 to 4 carbon atoms or a phenyl group. R
Examples of the ² alkyl group having 1 to 5 carbon atoms or the acyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and s.
Examples include an ec-butyl group, a tert-butyl group, an n-pentyl group, an acetyl group, a propionyl group, a butyryl group, and the like. Further, R ² is preferably an alkyl group having 1 to 4 carbon atoms.

Preferred specific examples of the organosilane represented by the general formula (1) include dimethyldimethoxysilane,
Examples include dimethyldiethoxysilane, isobutyltrimethoxysilane and phenyltriethoxysilane. These organosilanes can be used alone or in combination of two or more.

The above "specific organosilane compound"
In the electrodeposition solution used in the present invention, the organic particles preferably form composite particles with the organic particles. This `` composite particle '' refers to a particle formed in a state in which the compound constituting the organic particle and the specific organosilane compound are chemically bonded, and a specific particle on the surface or inside of the organic particle. It means that particles are formed while the organosilane compound is adsorbed. The amount of the specific organosilane compound to be used is preferably 0.1 to 500 parts by weight, more preferably 0.5 to 250 parts by weight, based on 100 parts by weight of the organic particles. When the amount of the specific organosilane compound used is less than 0.1 part by weight, the effect of using the specific organosilane compound may not be sufficiently obtained. When the use amount of the system compound exceeds 500 parts by weight, the adhesiveness of the obtained conductor tends to decrease.

The composite particles can be produced, for example, by the following method (a) or method (b), or a method combining method (a) and method (b). Method (a): an organosilane represented by the general formula (1) is added to the emulsion of the organic particles, at least a part of the organosilane is absorbed by the organic particles, and then the hydrolysis reaction of the organosilane is performed. And a method of allowing a condensation reaction to proceed. Method (b): a method in which a reaction for generating the organic particles is performed in the presence of a specific organosilane-based compound dispersed in an aqueous medium.

In the above method (a), in order for the organosilane represented by the general formula (1) to be absorbed by the organic particles,
The method may be such that the organosilane is added to the emulsion and sufficiently stirred. At this time, 10% by weight or more, especially 30% by weight of the added organosilane
It is preferable that the above-mentioned substances are absorbed by organic particles. Further, in order to suppress the progress of the hydrolysis / condensation reaction of the organosilane in a state where the absorption of the organosilane to the organic particles is insufficient, the pH of the reaction system is usually 4 to 1
It can be adjusted to 0, preferably 5 to 10, more preferably 6 to 8. Further, the treatment temperature for absorbing the organosilane into the organic particles is preferably 70 ° C. or lower, more preferably 50 ° C. or lower, and further preferably 0 to 30 ° C. The processing time is usually from 5 to 180 minutes, and particularly preferably about 20 to 60 minutes. The temperature at which the absorbed organosilane is hydrolyzed and condensed is usually 30 ° C. or higher, preferably 50 to 100 ° C.
° C, more preferably 70 to 90 ° C, and the reaction time is preferably 0.3 to 15 hours, more preferably 1 to 8 hours.

In the above method (b), the organosilane represented by the general formula (1) is prepared by using a homomixer or an ultrasonic mixer or the like in an aqueous solution of a strongly acidic emulsifier such as alkylbenzenesulfonic acid. By mixing, hydrolyzing and condensing, a specific organosilane compound dispersed in an aqueous medium can be obtained. Then, in the presence of the specific organosilane compound, the organic particles may be formed preferably by emulsion polymerization.

It is preferable that such interlayer short-circuit portions 22 and 32 contain conductive fine particles at a volume fraction of 40 to 80%, more preferably 60 to 80%.
It is. By satisfying such conditions, the conductivity is high, for example, the volume resistivity is preferably 1 × 10 ⁻⁴ Ω.
Cm or less, more preferably 0.5 × 10 ⁻⁴ Ω · cm or less, the interlayer short-circuit portions 22 and 32 can be reliably formed.

The multilayer wiring board as described above can be manufactured, for example, as follows. First, as shown in FIG. 2, a first substrate wiring layer 12 is formed on an upper surface of an insulating substrate 11.
Is formed on the lower surface of the insulating substrate 11, and a metal layer 13A electrically connected to the first substrate wiring layer 12 by the substrate short-circuit portion 14 is formed.
Prepare The core wiring board material 10A can be manufactured, for example, as follows.

First, as shown in FIG.
Material 10B formed by forming a metal layer 13A on the lower surface of
As shown in FIG. 4, a through-hole 14 penetrating through the insulating substrate 11 in the thickness direction corresponding to the substrate short-circuit portion to be formed is formed in the insulating substrate 11 in the laminated material 10B.
Form H. Next, by performing an electrodeposition process on the laminated material 10B using the metal layer 13A as a cathode electrode for deposition in the above-described electrodeposition solution, the surface of the metal layer 13A in the through-hole 14H is covered with the electrodeposition solution. The conductive fine particles and the organic particles are deposited to form a deposit, and the deposit is subjected to a heat treatment as necessary to extend through the insulating substrate 11 in the thickness direction as shown in FIG. The substrate short-circuit portion 14 is formed. Then, after the upper surface of the insulating substrate 11 is polished if necessary, the first substrate wiring layer 12 is formed on the upper surface of the insulating substrate 11, whereby the core wiring substrate material 10A shown in FIG. 2 is obtained. .

In the above, the through hole 1 is formed in the insulating substrate 11.
As a method of forming 4H, a small diameter through hole 14H is used.
In that point, a method of irradiating a laser can be suitably used. As a method of the electrodeposition treatment, it is preferable to use a constant voltage method in that the thickness can be easily controlled. Specific conditions for the electrodeposition treatment are appropriately set in consideration of the materials and concentrations of the conductive fine particles and the organic particles contained in the electrodeposition solution.
５００500 V, treatment time 0.5-200 minutes. In the case where the deposit formed by the electrodeposition treatment is subjected to the heat treatment, the conditions of the heat treatment are appropriately set in consideration of the material and the like of the organic particles in the electrodeposition liquid. The heating time is preferably 5 minutes or more, more preferably 10 minutes or more. As a method of forming the first substrate wiring layer 12, a wiring layer forming method conventionally used in the manufacture of a printed wiring board can be used. For example, the entire upper surface of the insulating substrate 11 is electrolessly plated. A metal layer is formed by applying electrolytic copper plating, a photoetching process is performed on the metal layer, and a part of the metal layer is removed to form a wiring layer. By performing lithography and electroless plating, an additive method of directly forming a wiring layer with a patterned metal layer, another method, and the like can be used.

As shown in FIG. 6, an upper insulating layer 20 having a through hole 22H corresponding to an interlayer short-circuit portion 22 to be formed is formed on the upper surface of the core wiring board material 10A. Next, the first substrate wiring layer 12 is subjected to electrodeposition in the above-mentioned electrodeposition solution using the first substrate wiring layer 12 as a deposition cathode electrode, thereby forming the first substrate wiring layer 1 in the through-hole 22H.
The conductive fine particles and the organic particles in the electrodeposition solution are deposited on the surface of the electrodeposition liquid 2 to form a deposit, and the deposit is subjected to a heat treatment as necessary, thereby forming an upper insulating layer 20 as shown in FIG. Inter-layer short-circuit portion 22 extending through
Is formed.

In the above, as a method of forming the upper insulating layer 20 in which the through-hole 22H is formed, a liquid radiation-curable resin material is applied to the upper surface of the core wiring substrate material 10A, and then the coating film is exposed. The upper insulating layer 2 in which the through holes 22H are formed by performing the processing and the development processing.
The upper insulating layer 20 is formed by applying a liquid thermosetting resin material to the surface of the core wiring board 10A or arranging a sheet-shaped thermosetting resin material on the surface of the core wiring board 10A and performing heat treatment. A method of forming the through-hole 22H by irradiating the upper insulating layer 20 with a laser can be used. The method and specific conditions for the electrodeposition process are the same as those for forming the substrate short-circuiting portion 14 described above.

After the upper insulating layer 20 and the interlayer short-circuit portion 22 are formed in this manner, and the surface of the upper insulating layer 20 is polished if necessary, as shown in FIG. The metal layer 21A is formed on the upper surface by performing electroless plating and electrolytic plating. Next, a second substrate wiring layer 13 is formed on the lower surface of the insulating substrate 10 by subjecting the metal layer 13A of the core wiring substrate material 10A to a photoetching process and removing a part thereof, thereby forming a second substrate wiring layer 13. The core wiring board 10 is formed. Thereafter, as shown in FIG. 10, through holes 32H corresponding to the interlayer short-circuit portions 32 to be formed are formed on the lower surface of the core wiring substrate 10.
Is formed on which the lower insulating layer 30 is formed. Next, in the above-described electrodeposition liquid, the second substrate wiring layer 13 is subjected to an electrodeposition process using the deposition electrode as a cathode electrode, so that the through holes 32 are formed.
In H, the conductive fine particles and the organic particles in the electrodeposition liquid are deposited on the surface of the second substrate wiring layer 13 to form a deposit, and this deposit is subjected to a heat treatment as necessary, thereby forming a diagram. As shown in FIG. 11, an interlayer short-circuit portion 22 extending through the upper insulating layer 20 in the thickness direction is formed. In the above, the lower insulating layer 30 in which the through hole 32H is formed
The method of forming, the method of electrodeposition and specific conditions are as follows:
This is the same as the formation of the lower insulating layer 20 and the interlayer short-circuit portion 22 described above.

Next, the metal layer 21A formed on the surface of the upper insulating layer 20 is subjected to photoetching treatment to remove a part thereof, thereby forming the upper wiring layer 21 as shown in FIG. After polishing the lower surface of the insulating layer 30 as necessary, the lower wiring layer 31 is formed on the lower surface of the lower insulating layer 30. Here, as a method of forming the lower wiring layer 31, a method of forming a wiring layer conventionally used in the manufacture of a printed wiring board is used in the same manner as the method of forming the first substrate wiring layer 12 described above. When the subtractive method is used, the photoetching process can be performed on the metal layer 21A in the formation of the upper wiring layer 21 by the same process as the photoetching process. Openings 26 for exposing component connection lands in the upper wiring layer 21 and the lower wiring layer 31 are respectively formed on the upper surface of the upper insulating layer 20 including the upper wiring layer 21 and the lower surface of the lower insulating layer 30 including the lower wiring layer 31. ,
By forming the solder resist layers 25 and 35 having 36, a multilayer wiring board having the configuration shown in FIG. 1 is obtained.

According to such a multilayer wiring board, in the electrodeposition liquid in which the conductive fine particles and the organic particles are dispersed, the electrodeposition treatment is performed by using the substrate wiring layers 12 and 13 as the deposition cathode electrodes. Since the interlayer short-circuit portions 22 and 32 are formed in a short time, high productivity can be obtained in manufacturing the multilayer wiring board. In addition, as the electrodeposition liquid, one having a low viscosity can be easily prepared, and by using such an electrodeposition liquid, the through-holes 21H, 21H, formed in each of the upper insulating layer 20 and the lower insulating layer 30 can be formed. Even if the diameter of 31H is small, the electrodeposition liquid is supplied through the through holes 21H, 31H.
As a result, the intended interlayer short-circuit portions 22 and 32
Can be reliably formed, and high connection reliability can be obtained.

The present invention is not limited to the above embodiment, and various changes can be made. For example, the insulating layer formed on the core wiring substrate may be only one of the one surface and the other surface of the core wiring substrate, or an insulating layer may be further laminated on the insulating layer. . Further, the core wiring board may have a multi-layer configuration as long as board wiring layers electrically connected to each other are formed on both surfaces.

[0057]

The present invention will be described in detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the following examples, “parts” and “%” mean “parts by weight” and “% by weight”.

[Preparation of Electrodeposition Solution] <Preparation Example 1> (1) Preparation of conductive fine particle dispersion: fine copper particles (manufactured by Vacuum Metallurgy Co., Ltd., number average primary particle diameter 0.050 μm) 20 prepared by CVD method And 80 parts of isopropyl alcohol by a homomixer, and then 0.6 parts of diethanolamine was added thereto, and the mixture was further subjected to ultrasonic dispersion treatment for 10 minutes. 20%). (2) Preparation of an emulsion of organic particles: obtained by reacting 35 parts of a blocked isocyanate composed of tolylene diisocyanate and 2-ethylhexanol with Epikote 828 (trade name, manufactured by Yuka Shell Epoxy) and diethylamine. The mixture was mixed with 65 parts of an epoxyamine adduct, and 2.5 parts of acetic acid was added as a pH adjuster. this,
By pouring into 400 parts of ion-exchanged water with stirring, an emulsion of cationic organic particles containing an epoxy resin precursor as a main component was prepared. (3) Preparation of electrodeposition solution: 500 parts of alcohol dispersion of copper fine particles obtained in (1) above (100 parts in terms of solid content)
And the emulsion 10 of the organic particles obtained in the above (2).
By mixing 0 parts (10 parts in terms of solid content),
An electrodeposition solution was prepared. Hereinafter, this electrodeposition liquid is referred to as “electrodeposition liquid (a)”. The volume ratio between the copper fine particles and the epoxy resin contained in the electrodeposition solution (a) was 53/47, and the water content measured by the Karl Fischer method was 6.5% by weight.

<Preparation Example 2> (1) Preparation of a conductive fine particle dispersion: copper fine particles produced by an electrolytic method (Kawatetsu Mining Co., Ltd., number average primary particle diameter of 0.1%).
5 μm) 20 parts and 30 parts of isopropyl alcohol were mixed with a homomixer, and then 50 parts of isopropyl alcohol was added, and further subjected to a dispersion treatment with a high-pressure homogenizer (manufactured by Shimizu Chemical Co., Ltd.), whereby copper fine particles without aggregates were obtained. Alcohol dispersion (solids concentration 20%)
Was prepared.

(2) Preparation of emulsion of organic particles: 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride 32.29 as tetracarboxylic dianhydride
g (90 mmol), and 1,3,3a, 4,5,9
b-Hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] -furan-
3.00 g (10 mmol) of 1,3-dione, 36.95 g (90 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane as a diamine compound
And organosiloxane (Shin-Etsu Chemical, product name "LP
7100 ") was dissolved in 450 g of N-methyl-2-pyrrolidone and reacted at room temperature for 12 hours. Then, pyridine 32 was added to the reaction solution.
g and 71 g of acetic anhydride were added, and a dehydration ring closure reaction was performed at 100 ° C. for 3 hours. Next, the reaction solution was purified by distillation under reduced pressure to obtain a polyimide solution having a solid content of 10%. A reaction vessel containing 100 parts of γ-butyrolactone was kept at 85 ° C. under a nitrogen gas atmosphere, and 65 parts of n-butyl acrylate, 30 parts of dimethylaminoethyl acrylate, 5 parts of glycidyl methacrylate and 5 parts of azo Solution polymerization was carried out with stirring while continuously adding a mixed solution consisting of 1 part of bisisobutyronitrile over 5 hours. After the dropping of the mixed solution was completed, stirring was continued at 85 ° C. for another 2 hours to complete the solution polymerization, and the solid content was reduced to 50%.
% Acrylic polymer solution. 500 parts (50 parts as solids) of the polyimide solution, 60 parts (30 parts as solids) of the acrylic polymer solution, and Epicoat 8
20 parts (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) and reacted at 70 ° C. for 3 hours. Then, 3 parts of acetic acid was gradually added and mixed to adjust the pH of the reaction solution. Next, 1000 parts of distilled water was gradually added to the reaction solution while vigorously stirring to prepare an emulsion of cationic organic particles containing a polyimide resin as a main component.

(3) Preparation of electrodeposition solution: 500 parts of dispersion liquid of copper fine particles obtained in the above (1) (100 parts in terms of solid content)
And the emulsion 10 of the organic particles obtained in the above (2).
0 parts (6.5 parts in terms of solid content) were mixed to prepare an electrodeposition solution. Hereinafter, this electrodeposition solution is referred to as “electrodeposition solution (b). The volume ratio between the copper fine particles contained in the electrodeposition solution (b) and the polyimide resin is 53/47, and was measured by the Karl Fischer method. The water content was 11% by weight.

Example 1 (1) Production of core wiring board material: First, the thickness was 500 μm
A laminated material in which a copper layer having a thickness of 18 μm is formed on an insulating substrate made of a glass fiber reinforced epoxy resin is prepared, and the insulating substrate in this laminated material has a diameter of 100 μm by a carbon dioxide laser device. Through holes were formed (see FIGS. 3 and 4). The laminated material is immersed in the electrodeposition solution (a) while protecting one surface of the metal layer, and the metal layer is used as a cathode electrode for deposition, and the temperature of the electrodeposition solution is 2
Electrodeposition by a constant voltage method is performed at 0 ° C., a distance between electrodes of 25 cm, an applied voltage of 200 V, and a processing time of 60 minutes to deposit conductive fine particles and organic particles in the through holes of the insulating substrate. After forming the body and pre-drying at 100 ° C. for 15 minutes, the substrate is short-circuited by heating at 170 ° C. for 30 minutes in a reducing atmosphere (in a 3% hydrogen-containing nitrogen gas). (See FIG. 5). Next, after polishing the surface of the insulating substrate in the laminated material, the surface of the insulating substrate is subjected to electroless copper plating and electrolytic copper plating to have a thickness of 20 μm.
m, a first substrate wiring layer is formed by subjecting the metal layer to a photo-etching process. The first substrate wiring layer is formed, and a substrate short-circuit portion is formed on the lower surface. A core wiring substrate material having a metal layer electrically connected to the first substrate wiring through the interposer was produced (see FIG. 2).

(2) Formation of upper insulating layer, interlayer short-circuit portion and core wiring board: An epoxy resin prepreg sheet having a thickness of 60 μm is placed on the upper surface of the core wiring board obtained in the above step (1) at a temperature of 165 ° C. , Pressure 30kg / c
The upper insulating layer is formed by thermocompression bonding under the condition of m ² , and the upper insulating layer is
A through hole having a diameter of 100 μm was formed (see FIG. 6). Next, in a state where the lower surface of the metal layer in the core wiring substrate material is protected, in the electrodeposition liquid (a), the temperature of the electrodeposition liquid is 20 ° C. Distance 25cm, applied voltage 200V, processing time 1
By performing electrodeposition treatment by a constant voltage method under the condition of 5 minutes, a deposit of conductive fine particles and organic particles is formed in the through hole of the upper insulating layer, and pre-dried at 100 ° C. for 15 minutes. After that, heat treatment was performed at 170 ° C. for 30 minutes in a reducing atmosphere (in a 3% hydrogen-containing nitrogen gas) to form an interlayer short-circuit portion (see FIG. 7). Next, after polishing the surface of the upper insulating layer, the surface of the upper insulating layer was subjected to electroless copper plating and electrolytic copper plating to form a metal layer having a thickness of 20 μm (FIG. 8).
reference). Thereafter, a second substrate wiring layer was formed by subjecting the metal layer of the core wiring substrate material to photoetching processing, thereby forming a core wiring substrate (see FIG. 9).

(3) Formation of lower insulating layer and interlayer short-circuit portion and upper wiring layer and lower wiring layer: core wiring obtained by the above step (2) and having upper insulating layer and interlayer short-circuit portion formed on the upper surface On the lower surface of the substrate, an epoxy resin prepreg sheet having a thickness of
A lower insulating layer was formed by thermocompression bonding under the condition of 0 kg / cm ² , and a through-hole having a diameter of 100 μm was formed in the lower insulating layer by a carbon dioxide laser device (FIG. 1).
0). Next, while protecting the upper surface of the metal layer formed on the upper insulating layer, the second
The substrate wiring layer was used as a cathode for deposition, the temperature of the electrodeposition solution was 20 ° C., the distance between the electrodes was 25 cm, and the applied voltage was 200.
V, an electrodeposition treatment was performed by a constant voltage method under the condition of a treatment time of 8 minutes to form a deposit of conductive fine particles and organic particles in the through-holes of the upper insulating layer. And then heat-treated at 170 ° C. for 30 minutes in a reducing atmosphere (in a 3% hydrogen-containing nitrogen gas) to form an interlayer short-circuit portion (FIG. 1).
1). Next, after polishing the surface of the lower insulating layer, the surface of the lower insulating layer was subjected to electroless copper plating and electrolytic copper plating to form a metal layer having a thickness of 20 μm. Thereafter, an upper wiring layer and a lower wiring layer were formed by subjecting a metal layer formed on each surface of the upper insulating layer and the lower insulating layer to photoetching treatment (see FIG. 12). Then, a multilayer resistive board of the present invention was manufactured by forming a solder resist layer on the surface of the upper insulating layer including the upper wiring layer and the surface of the lower insulating layer including the lower wiring layer. In the above, the proportion of the conductive fine particles in the substrate short-circuit portion and the interlayer short-circuit portion formed in each of the upper insulating layer and the lower insulating layer was about 53% by volume, respectively.

Example 2 In forming a substrate short-circuit portion and an interlayer short-circuit portion, an electrodeposition solution (b) was used instead of the electrodeposition solution (a).
Example 1 except that the conditions of the heat treatment after the pre-drying treatment of the deposit formed by the electrodeposition treatment were changed to 200 ° C. for 30 minutes in a reducing atmosphere (in a nitrogen gas containing 3% hydrogen). In the same manner as in the above, a multilayer wiring board of the present invention was manufactured. In the above, the ratio of the conductive fine particles in the substrate short-circuit portion and the interlayer short-circuit portion formed in each of the upper insulating layer and the lower insulating layer is about 5% by volume, respectively.
3%.

Comparative Example 1 Instead of forming a substrate short-circuit portion and an interlayer short-circuit portion with an electrodeposition solution, a copper-based conductive paste composition (viscosity: 100 Pa · s) was applied to a metal plate (thickness 1).
(00 μm, hole diameter 90 μm), filled into the through-holes by a screen printing machine, and heat-treated at 170 ° C. for 30 minutes in a reducing atmosphere (in a 3% hydrogen-containing nitrogen gas) to form a substrate short-circuit portion and an interlayer short-circuit portion. A multilayer wiring board for comparison was manufactured in the same manner as in Example 1 except that the multilayer wiring board was formed.

[Evaluation of Multilayer Wiring Board] (1) Initial electric resistance of wiring: The electric resistance between the connection lands of the upper wiring layer and the connection lands of the lower wiring layer in the multilayer wiring board was measured and averaged. The value was determined. (2) Electrical resistance of wiring after heat cycle test:
After leaving the multilayer wiring board at −55 ° C. for 30 minutes,
Operation for 30 minutes as one cycle
After 0 cycles, the electric resistance between the connection land of the upper wiring layer and the connection land of the lower wiring layer in the multilayer wiring board was measured, and the average value per connection land was obtained. The results are shown in Table 1.

[0068]

[Table 1]

As is clear from the results in Table 1, Example 1
And it was confirmed that the multilayer wiring board according to Example 2 had a low electric resistance of the wiring, a small change in the electric resistance of the wiring even after the heat cycle test, and a high connection reliability. .

[0070]

According to the multilayer wiring board of the present invention, in the electrodeposition liquid in which the conductive fine particles and the organic particles are dispersed, the substrate wiring layer is subjected to the electrodeposition treatment as a deposition electrode, whereby the interlayer short circuit is caused. Since the portions are formed in a short time, high productivity can be obtained in the production of the multilayer wiring board. In addition, as the electrodeposition liquid, one having a low viscosity can be easily prepared. By using such an electrodeposition liquid, even if the diameter of the through-hole formed in the insulating layer is small, the electrodeposition liquid can be used. As a result of the liquid landing sufficiently penetrating into the through-hole, an intended interlayer short-circuit portion can be reliably formed, and therefore, high connection reliability can be obtained.

According to the method for manufacturing a multilayer wiring board of the present invention,
In an electrodeposition solution in which conductive fine particles and organic particles are dispersed, by performing electrodeposition treatment using the substrate wiring layer as a deposition electrode, an interlayer short-circuit portion can be formed in a short time, so that high productivity is achieved. can get. In addition, as the electrodeposition liquid, one having a low viscosity can be easily prepared. By using such an electrodeposition liquid, even if the diameter of the through-hole formed in the insulating layer is small, the electrodeposition liquid can be used. As a result, the liquid can sufficiently enter the through-holes, so that the intended interlayer short-circuit portion can be reliably formed, so that a multilayer wiring board with high connection reliability can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a configuration of an example of a multilayer wiring board according to the present invention.

FIG. 2 is an explanatory sectional view showing a core wiring board material for obtaining the multilayer wiring board shown in FIG. 1;

FIG. 3 is an explanatory sectional view showing a laminated material for obtaining a core wiring board material shown in FIG. 2;

FIG. 4 is an explanatory cross-sectional view showing a state in which a through hole is formed in a laminated material.

FIG. 5 is an explanatory cross-sectional view showing a state where a substrate short-circuit portion is formed on an insulating substrate.

FIG. 6 is an explanatory cross-sectional view showing a state in which an upper insulating layer is formed on an upper surface of a core wiring board material.

FIG. 7 is an explanatory cross-sectional view showing a state where an interlayer short-circuit portion is formed in an upper insulating layer.

FIG. 8 is an explanatory cross-sectional view showing a state where a metal layer is formed on an upper surface of an upper insulating layer.

FIG. 9 is an explanatory cross-sectional view showing a state in which a second substrate wiring layer is formed on a lower surface of an insulating substrate to form a core wiring substrate.

FIG. 10 is an explanatory cross-sectional view showing a state where a lower insulating layer is formed on a lower surface of a core wiring substrate.

FIG. 11 is an explanatory sectional view showing a state where an interlayer short-circuit portion is formed in a lower insulating layer.

FIG. 12 is a diagram illustrating an upper wiring layer formed on a surface of the upper insulating layer;
FIG. 4 is an explanatory cross-sectional view showing a state where a lower wiring layer is formed on a lower surface of a lower insulating layer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 core wiring substrate 10A core wiring substrate material 10B laminated material 11 insulating substrate 12 first substrate insulating layer 13 second substrate insulating layer 13A metal layer 14 substrate short-circuit portion 14H through hole 20 upper insulating layer 21 upper wiring layer 21A metal Layer 22 Interlayer short-circuit part 22H Through hole 25 Solder resist layer 26 Opening 30 Lower insulating layer 31 Lower wiring layer 32 Interlayer short-circuit part 32H Through hole 35 Solder resist layer 36 Opening

Continued on the front page F term (reference) 5E317 AA24 BB01 BB11 BB24 CC31 CC53 CD27 GG16 5E346 AA15 CC04 CC09 CC32 DD12 EE09 FF15 FF18 GG15 HH07

Claims (6)

[Claims] 1. A core wiring board in which board wiring layers electrically connected to each other are formed on both surfaces of an insulating substrate; an insulating layer laminated on at least one surface of the core wiring board; A multilayer wiring board having an interconnect short-circuit portion extending through the insulating layer in a thickness direction thereof, wherein the interconnect layer electrically connects the interconnect layer to the substrate interconnect layer. The short-circuit portion is made of a conductor in which conductive fine particles are contained in a polymer substance, and the conductor is made of conductive fine particles and organic particles made of at least one of a polymerizable compound and a polymer in an aqueous medium. A multilayer wiring board formed by performing an electrodeposition treatment in a dispersed electrodeposition liquid. 2. The core wiring board has a board short-circuiting portion extending through the insulating board in a thickness direction thereof, for electrically connecting board wiring layers formed on both surfaces of the insulating board to each other, The substrate short-circuit portion is made of a conductive material in which conductive fine particles are contained in a polymer substance, and the conductive material is an organic particle made of conductive fine particles and at least one of a polymerizable compound and a polymer in an aqueous medium. 2. The multilayer wiring board according to claim 1, wherein the multilayer wiring board is formed by performing an electrodeposition treatment in an electrodeposition solution in which is dispersed. 3. The method according to claim 1, wherein the ratio of the conductive fine particles in the conductor constituting the interlayer short-circuit portion and / or the substrate short-circuit portion is 40 to 80% in volume fraction. Multilayer wiring board. 4. The method of manufacturing a multilayer wiring board according to claim 1, wherein the insulating substrate, a substrate wiring layer formed on one surface of the insulating substrate, A core wiring substrate material is formed on the other surface of the insulating substrate and made of a metal layer electrically connected to the substrate wiring layer, and is formed on one surface of the core wiring substrate material on the substrate wiring layer. Forming an insulating layer having a through hole formed corresponding to the interlayer short-circuit portion to be formed, and using the substrate wiring portion of the core wiring substrate material on which the insulating layer is formed as an electrode for deposition, the conductive fine particles in an aqueous medium. And the organic particles comprising at least one of a polymerizable compound and a polymer are dispersed in an electrodeposition solution in which an electric conductor constituting an interlayer short-circuit portion is formed in a through hole of the insulating layer. Having a step of performing Manufacturing method of a multilayer wiring board. 5. A substrate forming material having an insulating substrate and a metal layer formed on at least the other surface of the insulating substrate is prepared, and a through hole penetrating the insulating substrate in the substrate forming material in a thickness direction thereof is provided. A hole is formed, and a metal layer of the substrate forming material is used as a deposition electrode.
By performing electrodeposition in an electrodeposition solution in which conductive fine particles and organic particles comprising at least one of a polymerizable compound and a polymer are dispersed in an aqueous medium, a substrate short circuit occurs in a through hole of the insulating substrate. 5. The multilayer wiring board according to claim 4, wherein a core wiring board material is formed by forming a conductor constituting a portion, and thereafter forming a board wiring portion on one surface of the insulating substrate. Method. 6. The multilayer wiring board according to claim 4, wherein the ratio between the conductive fine particles and the organic particles in the electrodeposition liquid is 80:20 to 40:60 by volume. Production method.