JP3300653B2 - Adhesive for electroless plating and multilayer printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adhesive for electroless plating and a multilayer printed wiring board using the same.
In particular, the structure of an adhesive for electroless plating and a multilayer printed wiring manufactured using the adhesive, which can form a via hole and a fine pattern with a diameter of less than 100 μm and can effectively remove the development residue in the via hole. Suggest board.

[0002]

2. Description of the Related Art In recent years, so-called build-up multilayer wiring boards have been receiving attention due to a demand for higher density of the multilayer wiring boards. This build-up multilayer wiring board is manufactured by a method disclosed in, for example, Japanese Patent Publication No. 4-55555. That is, on the core substrate, a photosensitive adhesive for electroless plating is applied, dried, exposed, and developed to form an interlayer resin insulating layer having a via hole opening. After the surface of the resin insulation layer is roughened by treatment with an oxidizing agent, a plating resist is provided on the roughened surface, and then electroless plating is performed on the non-resist-formed portion to form a conductor circuit pattern including via holes. By repeating such a process a plurality of times, a multilayered build-up wiring board can be obtained.

As an adhesive for electroless plating used for an interlayer resin insulating layer of such a build-up wiring board, Japanese Patent Application Laid-Open No. 7-34048 (US Pat. No. 5,519,177) discloses a resin matrix having a tough epoxy-polyether. An adhesive for electroless plating using a sulfone (PES) resin composite is disclosed.

However, in the structure of the adhesive for electroless plating, if it is attempted to form a via hole having a diameter of less than 100 μm in order to increase the density of wiring, PES is not completely developed with a solvent and the via hole is formed. Remains at the bottom of the opening, and because PES is difficult to decompose with an oxidizing agent,
There was a problem that the residual PES could not be completely removed even after the roughening treatment.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art.
The main object is to propose an adhesive for electroless plating having a configuration capable of effectively removing the development residue in the via hole. Another object of the present invention is to provide a multilayer printed wiring board that can form fine via holes and fine patterns by using the above-mentioned adhesive for electroless plating, and has excellent reliability such as peel strength. It is in.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to realize the above object. As a result, P in the resin composite
It has been found that PES remains easily generated because the amount of ES is too large, and that a decrease in the amount of PES does not cause a decrease in peel strength within a certain range.

The present invention is based on such knowledge, and the gist configuration thereof is as follows. (1) In an adhesive for electroless plating in which cured heat-resistant resin particles soluble in an acid or an oxidizing agent are dispersed in an uncured heat-resistant resin matrix which becomes hardly soluble in an acid or an oxidizing agent by a curing treatment, the heat-resistant resin matrix, which is composed of a thermosetting resin and a thermoplastic resin, the amount of the thermoplastic resin is 15 to 25 wt% based on the solids content of the heat-resistant resin matrix, the heat-resistant resin Ma
The heat-resistant resin particles dispersed in the matrix have an average particle size.
Is 0.1 to 1.0 μm .

(2) On a substrate on which a conductive circuit is formed, heat-resistant resin particles which are hardly soluble in an acid or an oxidizing agent are cured in a heat-resistant resin matrix which is hardly soluble in an acid or an oxidizing agent. A dispersed electroless plating adhesive layer is formed, and the surface of the electroless plating adhesive layer has a roughened surface formed by dissolving and removing heat-resistant resin particles,
In the multilayer printed wiring board in which the upper conductor circuit is formed on the roughened surface, the heat-resistant resin matrix of the adhesive for electroless plating is composed of a composite of a thermosetting resin and a thermoplastic resin. The amount of the thermoplastic resin is 15 to 25% by weight based on the solid content of the heat resistant resin matrix.
Ri, heat resistance is dispersed in the heat-resistant resin matrix
The resin particle is a multilayer printed wiring board characterized by having an average particle diameter of 0.1 to 1.0 μm .

[0009] In the multilayer printed wiring board according to the above (2), the adhesive layer for electroless plating is composed of two layers, and the mixture of the heat-resistant resin particles in the adhesive layer for electroless plating on the substrate side. The amount is 20 to 50% by weight based on the solid content of the heat-resistant resin matrix, and the compounding amount of the heat-resistant resin particles in the adhesive layer for electroless plating is based on the solid content of the heat-resistant resin matrix. Is preferably not less than 5% by weight and less than 20% by weight. The average particle size of the heat-resistant resin particles is
0.1 to 1.0 μm, the adhesive layer for electroless plating has a via hole with a diameter of less than 100 μm, and the conductor circuit consists of an electroless plating film and an electrolytic plating film. It is preferable that a roughened layer is formed on at least a part of the surface of the conductor circuit.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The adhesive for electroless plating according to the present invention is characterized in that the amount of thermoplastic resin such as PES in the resin composite constituting the heat-resistant resin matrix is less than a certain amount, that is, the heat-resistant resin matrix. 15 to 25 with respect to solid content of
Weight percent and in the heat-resistant resin matrix
The average particle size of the heat-resistant resin particles dispersed in 0.1 to 1.
The feature is that it is 0 μm . Such electroless plating
By applying a coating adhesive on the substrate and curing it.
In the obtained interlayer resin insulating layer, the opening diameter is less than 100 μm.
When a via hole is provided, a thermoplastic resin such as PES remains at the bottom of the opening for forming the via hole during the developing step.
It hardly remains, and even if it remains, its amount is very small and is removed together with a thermosetting resin such as an epoxy resin during the roughening treatment.

In the adhesive for electroless plating of the present invention, an epoxy resin, a phenol resin, a polyimide resin, or the like can be used as the thermosetting resin. When the thermosetting resin is made to be photosensitive, a thermosetting group is reacted with methacrylic acid, acrylic acid, or the like to acrylate. Particularly, acrylate of epoxy resin is most suitable. As the epoxy resin, a novolak type epoxy resin, an alicyclic epoxy resin, or the like can be used.

Examples of the thermoplastic resin include polyether sulfone, polysulfone, polyphenylene sulfone,
Polyphenylene sulfide, polyphenyl ether,
Polyetherimide or the like can be used.

In particular, as the heat resistant resin matrix constituting the adhesive for electroless plating of the present invention, it is desirable to use a composite of epoxy resin (including acrylate of epoxy resin) and polytersulfone (PES).
The reason is that the use of such a composite makes it possible to increase the toughness of the adhesive for electroless plating. In this case, P
The blending amount of ES is preferably 15 to 25% by weight. The reason for this is that if it is 15% by weight or more, practical peel strength can be maintained.

In the present invention, the average particle size of the heat-resistant resin particles in the adhesive is 1.0 μm or less (preferably 0.1 to 1.0 μm).
By making the anchor depth of the roughened surface shallow,
In addition to preventing conductor residue between lines, a fine pattern (L / S = 25/25 μm) is realized, and the amount of heat-resistant resin particles on the substrate side (inner layer side) is increased compared to the opposite side. Thereby, it is preferable that the resin residue generated at the bottom of the opening for forming the via hole can be effectively removed at the time of the roughening treatment, thereby ensuring the connection reliability of the via hole. The average particle size of the heat-resistant resin particles is 0.1 to 1.0
The reason why μm is optimal is that the anchor on the roughened surface can be made shallower, the via hole diameter does not increase due to the roughening treatment, and the undeveloped residue can be removed during the roughening treatment.

In the present invention, the adhesive layer for electroless plating is composed of two layers, and the compounding amount of the heat-resistant resin particles in the adhesive layer for electroless plating on the substrate side is based on the solid content of the heat-resistant resin matrix. 20 to 50% by weight, and the amount of the heat-resistant resin particles in the adhesive layer for electroless plating is 5% by weight or more and 20% by weight based on the solid content of the heat-resistant resin matrix.
It is preferably less than. The reason for this is that the adhesive layer for electroless plating closer to the substrate (inner layer side) dissolves and removes the development residue at the bottom of the via hole during the roughening treatment, so that the amount of the heat-resistant resin particles is increased. While needing,
This is because the adhesive layer for electroless plating on the opposite side needs to reduce the amount of heat-resistant resin particles in order to make the anchor on the roughened surface shallow and prevent residual conductor.

It is necessary that the heat-resistant resin particles have been previously cured. The reason is that the heat-resistant resin particles are dissolved in a solvent that dissolves the resin matrix if not cured, are uniformly mixed with the resin matrix, and the resin particles alone cannot be selectively dissolved and removed with an acid or an oxidizing agent. Because.

As the heat-resistant resin particles, amino resins (melamine resins, urea resins, guanamine resins, etc.), epoxy resins, bismaleimide-triazine resins and the like are preferred.
The epoxy resin is advantageous in that it can be arbitrarily prepared by dissolving in an acid or an oxidizing agent or hardly dissolving in an acid or an oxidizing agent by appropriately selecting the type of the oligomer or 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, whereas a resin obtained by curing a cresol novolac type epoxy resin with an imidazole curing agent is hardly dissolved in chromic acid.

The adhesive for electroless plating of the present invention may be impregnated into a fibrous substrate such as a glass cloth to form a B-stage state, or may be formed into a film. Further, it may be formed into a substrate shape. In the adhesive for electroless plating of the present invention, the constituent resin may be halogenated to make it flame-retardant, or a dye, a pigment, or an ultraviolet absorber may be added. Further, a fibrous filler or an inorganic filler may be filled to adjust the toughness and the coefficient of thermal expansion.

In the printed wiring board using the adhesive for electroless plating of the present invention, the anchor depth of the roughened surface is Rmax = 1.
５5 μm. This anchor depth is about 1/2 of the anchor depth Rmax = 10 μm of the roughened surface formed by the conventional adhesive, and even if the electroless plating film under the plating resist is dissolved and removed, the plating residue remains. In addition, the amount of palladium catalyst nuclei under the plating resist can be reduced.

In the multilayer printed wiring board of the present invention, a roughened layer is formed on the surface of the conductor circuit formed on the substrate in order to improve the adhesion with the adhesive layer for electroless plating. It is desirable. This roughened layer may be formed on the upper surface of the conductor circuit when the substrate is formed by the full additive method, and may be formed on the side surface or the entire surface of the conductor circuit when the substrate is formed by the subtractive method. desirable. By such a roughened layer, the adhesiveness with the adhesive layer for electroless plating is improved, and cracks caused by a difference in thermal expansion coefficient between the conductor circuit and the adhesive for electroless plating during a heat cycle are suppressed. Can be.

In the case where the roughened layer is formed on the surface of the conductor circuit, when the opening for forming the via hole is formed in the adhesive layer for electroless plating, the roughened layer on the bottom of the opening is developed. Unsatisfactory resin tends to remain. In this regard, the present invention is advantageous because such residual resin can be removed during the roughening treatment of the adhesive layer for electroless plating.

Further, the roughened layer may be formed on the upper surface, the side surface, or the entire surface of the conductor circuit formed on the roughened surface of the adhesive for electroless plating. The reason for this is that cracks that occur during a heat cycle can be suppressed by improving the adhesion to the solder resist that covers the conductor circuit and the upper interlayer resin insulation layer.

Next, a method for manufacturing a printed wiring board according to the present invention will be described by taking a semi-additive method as an example. (1) First, a through hole is drilled in the substrate, and a through hole is formed by applying electroless plating to the wall surface of the through hole and the surface of the copper foil. As the substrate, a resin substrate such as a glass epoxy substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a fluororesin substrate, or a copper-clad laminate of these resins, a ceramic substrate, a metal substrate, or the like can be used. In particular, when the dielectric constant is considered, it is preferable to use a double-sided copper-clad fluororesin (polytetrafluoroethylene or the like) substrate. This substrate is obtained by thermocompression bonding copper foil having one surface roughened to a fluororesin substrate. Copper plating is preferred as the electroless plating. In the case of a substrate with poor plating coverage, such as a fluororesin substrate, a treatment using a pretreatment liquid (trade name: tetra-etch) composed of an organic acid or the like,
Perform surface modification such as plasma treatment.

(2) Next, electrolytic plating is performed for thickening. Copper plating is preferable as the electrolytic plating. Further, a roughening layer may be provided by roughening the inner wall of the through hole and the surface of the electrolytic plating film. The roughened layer may be formed by a blackening (oxidation) -reduction treatment, by a spray treatment (etching treatment) of a mixed aqueous solution of an organic acid and a cupric complex, or by a copper-nickel-phosphorus needle-like alloy. Some are by plating.

When a roughened layer is formed by electroless plating in these treatments, the copper ion concentration, nickel ion concentration and hypophosphite ion concentration are each 2.2 × 10 4
^{-2 to} 4.1 × 10 ^-2 mol / l, 2.2 × 10 ^{-3 to} 4.1 × 10 ^-3 mol
/ L, an aqueous plating solution having a composition of 0.20 to 0.25 mol / l is desirably used. This is because the crystal structure of the film deposited in this range has a needle-like structure and is excellent in anchor effect. To this aqueous electroless plating solution, a complexing agent or an additive may be added in addition to the above compounds. In addition, 0.01 to 10 g / l
May be added. Examples of the surfactant include Surfynol 440 and 46 manufactured by Nissin Chemical Industry.
It is desirable to use an acetylene-containing polyoxyethylene surfactant such as 5,485. That is, when a roughened layer is formed by electroless plating, copper sulfate 1 to 40 g / l,
Nickel sulfate 0.1-6.0 g / l, citric acid 10-20 g /
l, hypophosphite 10-100 g / l, boric acid 10-40 g /
It is desirable to use an aqueous plating solution having a solution composition of 0.01 to 10 g / l of a surfactant.

When a roughened layer is formed by oxidation-reduction treatment, NaOH (10 g / l), NaClO ₂ (40 g / l), Na ₃ PO
₄ (6 g / l) as an oxidation bath, NaOH (10 g / l), NaBH
₄ (5 g / l) is desirably used as the reducing bath.

When a roughened layer is formed by etching using a mixed aqueous solution of an organic acid and a cupric complex, a CZ8100 solution manufactured by Mec Co., Ltd. is typically used.
The copper surface is made uneven using the oxidizing power of copper.

The roughened layer may be coated with a layer of a metal or a noble metal whose ionization tendency is larger than copper and equal to or less than titanium. The reason for this is that the metal or noble metal layer covers the roughened layer and prevents local electrode reaction of the conductor circuit when roughening the interlayer insulating layer, thereby preventing the conductor circuit from melting. . The thickness of this layer is preferably 0.01 to 2 μm. Such metals include titanium, aluminum,
It is at least one selected from zinc, iron, indium, thallium, cobalt, nickel, tin, lead and bismuth. The noble metals include gold, silver, platinum and palladium. Among them, tin is advantageous because it can form a thin layer by electroless displacement plating and can follow a roughened layer. In the case of tin, tin borofluoride-thiourea or tin chloride-thiourea solution is used, and the substitution reaction of Cu-Sn is performed.
A Sn layer of about 0.01 to 2 μm is formed. On the other hand, in the case of a noble metal, a method such as sputtering or vapor deposition is adopted.

(3) Next, metal particle paste is filled in the through holes. Specifically, the metal particle paste is filled in the through-hole by being applied by a printing method on a substrate on which a mask having an opening formed in the through-hole is placed, and after filling, dried and cured.

This metal particle paste comprises metal particles and a resin, and may contain a solvent if necessary. As metal particles, Cu, Au, Ag, Al, Ni, Pd, Pt, Ti, Cr, Sn
/ Pb can be used. The particle size of the metal particles is 1.0
1010 μm is preferred. In addition, as a resin to be used, epoxy resin, phenol resin, polyimide resin, fluorine resin such as polytetrafluoroethylene (PTFE), bismaleimide triazine (BT) resin, FEP, PFA,
PPS, PEN, PES, nylon, aramid, PEE
K, PEKK, PET and the like can be used. As the solvent, NMP (normal methylpyrrolidone), DMD
G (diethylene glycol dimethyl ether), glycerin, water, 1- or 2- or 3-cyclohexanol, cyclohexanone, methyl cellosolve, methyl cellosolve acetate, methanol, ethanol, butanol, propanol, bisphenol A type, F type epoxy and the like are used. it can.

A metal surface modifier such as a silane coupling agent may be added to the metal particle paste in order to increase the adhesion between the metal particles and the resin. Further, as other additives, an antifoaming agent such as an acrylic antifoaming agent or a silicon-based antifoaming agent, or an inorganic filler such as silica, alumina, or talc may be added.

In particular, the optimum composition of the metal particle paste is a combination of a mixture of 7: 3 by weight of Cu powder and a solventless epoxy and a curing agent, or a 7: 3: 3 by weight ratio of Cu.
A combination of flour, PPS and NMP is preferred.

Further, the metal particle paste protruding from the through-hole and the roughened layer on the surface of the electrolytic plating film of the substrate are removed by polishing to flatten the surface of the substrate. Polishing is
Belt sander and buffing are good. As a result of this polishing, a part of the metal particles is exposed on the surface, and the metal particles in the exposed portion are integrated with the plating film of the conductor layer, thereby exhibiting good adhesion.

(4) After providing a catalyst nucleus on the surface of the substrate flattened in the above (3), electroless plating and electrolytic plating are performed.
Further, an etching resist is formed, and a portion where the resist is not formed is etched to form a conductor layer portion covering the conductor circuit portion and the metal particle paste. As the etchant, an aqueous solution of sulfuric acid-hydrogen peroxide, an aqueous solution of persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate, or an aqueous solution of ferric chloride or cupric chloride is preferable.

(5) Then, after the etching resist is peeled off to form independent conductor circuits and conductor layers, a roughened layer is formed on the surfaces of the conductor circuits and conductor layers. If a roughened layer is formed on the surface of the conductor layer covering the conductor circuit and the metal particle paste, the conductor has excellent adhesion to the interlayer resin insulation layer. No crack originating from the interface with the insulating layer. On the other hand, the conductor layer covering the metal particle paste has improved adhesion to via holes that are electrically connected. The method of forming the roughened layer is as described above, and includes blackening (oxidation) -reduction treatment, needle-like alloy plating,
Alternatively, there is a method of forming by etching. Further, after the roughening, a resin may be filled between the conductor circuits, and the surface may be polished and smoothed. At this time, as the filling resin,
A composition comprising a bisphenol F type epoxy resin, an imidazole curing agent and inorganic particles is preferred.

(7) An interlayer resin insulating layer is formed on the wiring board thus manufactured. As the interlayer resin insulation layer, the adhesive for electroless plating of the present invention is employed. More preferably, the adhesive layer for electroless plating on the side close to the substrate has a compounding amount of the heat-resistant resin particles of 20 to 50% by weight based on the solid content of the heat-resistant resin matrix, while the electroless plating layer on the other side has In the adhesive layer for plating, the amount of the heat-resistant resin particles is 5% by weight or more based on the solid content of the heat-resistant resin matrix.
% By weight.

Such an interlayer resin insulating agent is applied on a substrate using a roll coater, a curtain coater, or the like, and dried. In this state, the thickness of the interlayer resin insulation layer on the conductor circuit pattern is thin, and the thickness of the interlayer resin insulation layer on the conductor circuit having a large area is thick, and irregularities often occur. It is preferable that the surface of the interlayer resin insulating layer is flattened by using a metal roll or a metal roll while pressing while heating.

(8) The interlayer resin insulation layer is cured to provide an opening for forming a via hole. The curing treatment is performed by thermosetting when the resin matrix of the adhesive for electroless plating is a thermosetting resin, and by exposure to ultraviolet rays or the like when the resin matrix is a photosensitive resin. The opening for forming the via hole is formed by laser light or oxygen plasma when the resin matrix of the adhesive for electroless plating is a thermosetting resin, or by exposure and development when the resin matrix is a photosensitive resin. In particular, in the case of exposure and development processing, a photomask (preferably a glass substrate) on which the above-described circular pattern for forming a via hole is drawn is placed in close contact with the photosensitive interlayer resin insulating layer, and is exposed and developed. To process.

The adhesive layer for electroless plating has a thickness of 45
μm or less, more preferably 20 to 45 μm. The reason is that if it exceeds 45 μm, the diameter of the via hole cannot be reduced, and a via hole of less than 100 μm cannot be obtained. In addition, the thickness of the adhesive layer for electroless plating
When the average particle diameter of the heat-resistant resin particles is set to 45 μm or less and the average particle diameter of the heat-resistant resin particles exceeds 2 μm, the layers are communicated by the roughening treatment. In this regard, since the average particle size of the heat-resistant resin particles used in the present invention is as small as 0.1 to 1.0 μm, such a problem can be solved.

(9) The surface of the interlayer resin insulating layer (adhesive layer for electroless plating) having the opening formed in (8) is roughened. In the present invention using an adhesive for electroless plating, resin particles present on the surface of the adhesive are dissolved and removed with an acid or an oxidizing agent, and the surface of the adhesive layer is roughened. The depth of the anchor by this roughening is preferably about 1 to 5 μm. Examples of the acid include phosphoric acid, hydrochloric acid, sulfuric acid, and organic acids such as formic acid and acetic acid, and it is particularly 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 chromic acid or permanganate (such as potassium permanganate).

(10) A catalyst nucleus is provided on the roughened surface of the interlayer resin insulating layer. It is desirable to use a noble metal ion or a noble metal colloid for providing the catalyst nucleus, and generally, palladium chloride or a palladium colloid is used. In addition,
It is desirable to perform a heat treatment to fix the catalyst core. Palladium is preferred as such a catalyst core.

(11) Next, electroless plating is performed on the roughened surface of the interlayer resin insulating layer, and an electroless plating film is formed on the entire surface. The thickness of the electroless plating film is 0.1 to 5 μm, more preferably 0.2 to 2.0 μm. The electroless plating is preferably an electroless copper plating. As the plating solution, a conventional plating solution can be used. For example, 29 g / l copper sulfate, 25 g / l sodium carbonate, 140 g / l tartrate, 40 g / l sodium hydroxide, 37% formaldehyde 150 ml, A composition having a pH of 11.5 is preferred.

(12) A photosensitive resin film (dry film) is laminated on the electroless plating film formed in (11), and a photomask (glass substrate) on which a plating resist pattern is drawn on the photosensitive resin film. Are placed in close contact with each other, and exposed and developed to form a plating resist pattern.

(13) Electrolytic plating is applied to the portion where the plating resist is not formed to provide a conductor circuit portion and a via hole. Here, it is desirable to use copper plating as the electrolytic plating. The thickness is preferably 10 to 20 μm. It is preferable that an electrolytic plating film is filled in the via hole to form a so-called filled via. This is because the flatness of the interlayer resin insulating layer can be ensured. The via hole may be formed immediately above the through hole provided in the substrate. This is for higher density.

(14) After removing the plating resist, the electroless plating film under the plating resist is replaced with a mixture of sulfuric acid and hydrogen peroxide, sodium persulfate, ammonium persulfate, ferric chloride, cupric chloride, etc. Dissolves and removes with an etching solution of the above to form an independent conductor circuit. Further, the palladium catalyst nuclei on the exposed roughened surface are dissolved and removed with chromic acid or the like.

(15) By repeating the above-mentioned steps on this substrate, a further upper layer conductive circuit can be provided.
Hereinafter, description will be made based on embodiments.

[0047]

[Electroless plating aqueous solution]

 EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l PEG 0.1 g / l [Electroless plating conditions] 30 minutes at a liquid temperature of 70 ° C.

Then, electrolytic copper plating was performed under the following conditions to form an electrolytic copper plating film having a thickness of 15 μm (FIG. 1 (c)).
reference). [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(2) A substrate having a conductor (including through holes) formed of an electroless copper plating film and an electrolytic copper plating film formed on the entire surface is washed with water, dried, and then subjected to NaOH (10 g / l), NaCl
O ₂ (40 g / l) and Na ₃ PO ₄ (6 g / l) are subjected to an oxidation-reduction treatment using an oxidation bath (blackening bath), NaOH (10 g / l), and NaBH ₄ (6 g / l) as a reduction bath. A roughened layer 4 was provided on the entire surface of the conductor including the through hole 3 (see FIG. 1 (d)).

(3) Next, a metal particle paste 5 containing copper particles having an average particle diameter of 15 μm (manufactured by Tatsuta Electric Co., Ltd., DD paste: non-conductive filled copper paste) 5 is filled into the through hole 3 by screen printing. 30 minutes at 100 ℃, 2 at 180 ℃
It was dried and cured under the conditions of time. Then, the metal particle paste 5 protruding from the roughened surface on the upper surface of the conductor and the through hole 3 is removed by belt sanding using # 400 belt abrasive paper (manufactured by Sankyo Rikagaku Co., Ltd.). In order to remove this, the substrate surface was flattened by buffing using alumina granulation or SiC granulation (see FIG. 1 (e)).

(4) An electroless copper plating film having a thickness of 0.6 μm is formed by applying a palladium catalyst (manufactured by Atotech) to the substrate surface flattened in the above (3) and subjecting the substrate surface to electroless copper plating according to a conventional method. 6 was formed (see FIG. 1 (f)).

(5) Next, electrolytic copper plating is performed under the following conditions to form an electrolytic copper plating film 7 having a thickness of 15 μm, a portion to be a conductor circuit 9 is thickened, and a metal filled in the through hole 3 is formed. A portion to be the conductor layer 10 covering the particle paste 5 was formed. [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1 A / dm ² hours 30 minutes Temperature Room temperature

(6) A commercially available photosensitive dry film is adhered to both sides of the substrate on which the portions to be the conductor circuits 9 and the conductor layers 10 are formed, and a mask is placed on the substrate, and exposure is performed at 100 mJ / cm ² .
The film was developed with 8% sodium carbonate to form an etching resist 8 having a thickness of 15 μm (see FIG. 2A).

(7) Then, the plating film in the portion where the etching resist 8 is not formed is dissolved and removed by etching using a mixed solution of sulfuric acid and hydrogen peroxide, and the etching resist 8 is stripped with 5% KOH. After removal, a conductor layer 10 covering the independent conductor circuit 9 and the metal particle paste 5 was formed (see FIG. 2 (b)). Further, the conductor surface was roughened by an oxidation-reduction treatment.

[Preparation of Resin Filler] 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell, molecular weight: 310, YL983U), S having an average particle size of 1.6 μm and having a surface coated with a silane coupling agent
iO ₂ spherical particles (manufactured by Admatech, CRS 1101-CE, where the maximum particle size is not more than the thickness (15 μm) of the inner layer copper pattern described below) 170 parts by weight, leveling agent (manufactured by San Nopco, Perenol S4) 1.5 The weight of the mixture is kneaded with three rolls and the viscosity of the mixture is 45,000 ~ at 23 ± 1 ° C.
Adjusted to 49,000cps. 6.5 parts by weight of imidazole curing agent (2E4MZ-CN, manufactured by Shikoku Chemicals). These were mixed to prepare a resin filler 12a.

(8) The prepared resin filler 12a is applied to one surface of the substrate by using a roll coater to fill the space between the conductor circuits 9 or the conductor layers 10 and dried at 70 ° C. for 20 minutes. Similarly, the other surface was filled with the resin filler 12a between the conductor circuit 9 or the conductor layer 10, and dried by heating at 70 ° C. for 20 minutes.

(9) Replace one side of the substrate after the above processing with #
Belt sanding using 600 belt polishing papers (manufactured by Sankyo Rikagaku Co., Ltd.) so that the resin filler 12a does not remain on the surface of the inner layer copper patterns 9 and 10, and then to remove the scratches caused by the belt sanding. Was buffed. Such a series of polishing was similarly performed on the other surface of the substrate. Then at 100 ° C for 1 hour and at 120 ° C for 3 hours.
Heat treatment was performed for 1 hour at 150 ° C. and for 7 hours at 180 ° C. to cure the resin filler 12a.

(10) Next, on the surface of the conductor layer 10 covering the conductor circuit 9 and the metal particle paste 5, a roughened layer (irregular layer) 11 made of a Cu-Ni-P alloy and having a thickness of 2.5 μm is formed. Further, a Sn layer having a thickness of 0.05 μm was formed on the surface of the roughened layer 11 (see FIG. 2C, the Sn layer is not shown). The formation method is as follows. That is, the substrate was acid-degreased and soft-etched, and then treated with a catalyst solution comprising palladium chloride and an organic acid to provide a Pd catalyst. After activating this catalyst, copper sulfate 8 g / l, nickel sulfate 0.6g /
l, citric acid 15 g / l, sodium hypophosphite 29 g /
1, boric acid 31 g / l, surfactant 0.1 g / l, pH = 9
The surface of the copper conductor circuit was formed with a 2.5 μm-thick roughened layer 11 (concavo-convex layer) on the entire surface of the copper conductor circuit. Further, it was immersed in an electroless tin displacement plating bath composed of 0.1 mol / l tin borofluoride-1.0 mol / l thiourea solution at 50 ° C. for 1 hour, and a 0.05 μm thick tin displacement plating layer was formed on the surface of the roughened layer. Was provided.

(11) An adhesive for electroless plating was prepared as follows. [Adhesive on side (lower layer) close to substrate] 35 parts by weight (solid content: 80%) of 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight: 2500), 4 parts by weight of photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315), defoaming 0.5 part by weight of an agent (manufactured by San Nopco, trade name: S-65) and 3.6 parts by weight of NMP were mixed with stirring. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 14.49 parts by weight of an average particle size of 0.5 μm, and then 20 parts by weight of NMP was further added thereto, followed by stirring and mixing. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Was mixed with stirring. These were mixed to obtain an adhesive for electroless plating.

[Adhesive on opposite side (upper layer) of substrate] 35 parts by weight (solid content: 80%) of 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight: 2500), 4 parts by weight of photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315), defoaming 0.5 part by weight of an agent (manufactured by San Nopco, trade name: S-65) and 3.6 parts by weight of NMP were mixed with stirring. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 7.245 parts by weight of a powder having an average particle size of 0.5 μm, and then 20 parts by weight of NMP was further added and mixed with stirring. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba-Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Parts were stirred and mixed. These were mixed to obtain an adhesive for electroless plating.

(12) The photosensitive adhesive solution prepared in the above (11) is sequentially applied to both surfaces of the substrate by using a roll coater, left in a horizontal state for 20 minutes, and then left at 60 ° C. for 30 minutes. Was dried to form an adhesive layer 12b (two-layer structure) having a thickness of 60 μm (see FIG. 2 (d)). Further, a polyethylene terephthalate film was stuck on the adhesive layer 12b via an adhesive.

(13) A 5 mm thick soda lime glass substrate on which a circular pattern (mask pattern) having the same shape as the via hole is drawn on both surfaces of the substrate on which the adhesive layer 12b is formed, using a 5 μm thick light-shielding ink. The side on which the circular pattern was drawn was placed in close contact with the adhesive layer 12b, and was exposed to ultraviolet light.

(14) The exposed substrate was spray-developed with a DMTG (triethylene glycol dimethyl ether) solution to form an opening serving as a 80 μmφ via hole in the adhesive layer 12b. Further, the substrate is exposed at 3000 mJ / cm ² using an ultra-high pressure mercury lamp, and is exposed at 100 ° C. for 1 hour.
By performing the heat treatment at 150 ° C. for 5 hours, an adhesive layer 12 having a thickness of 35 μm having openings (opening 13 for forming via holes) having excellent dimensional accuracy corresponding to a photomask film.
b was formed (see FIG. 2 (d)). Note that the roughened layer is partially exposed in the opening serving as the via hole.

(15) The substrate on which the via hole forming openings 13 are formed is immersed in chromic acid for 10 minutes to dissolve and remove the epoxy resin particles present on the surface of the adhesive layer. Roughened, then neutralized solution (Shipley)
And then washed with water.

(16) By applying a palladium catalyst (manufactured by Atotech) to the substrate that has been subjected to the surface roughening treatment (roughening depth: 5 μm), the surface of the adhesive layer 12 b and the surface of the via hole opening 13 are A catalyst core was provided.

(17) The substrate was immersed in an electroless copper plating aqueous solution having the following composition to form an electroless copper plating film 14 having a thickness of 0.6 μm on the entire rough surface (see FIG. 3A). . [Electroless plating aqueous solution] EDTA 150 g / l Copper sulfate 20 g / l HCHO 30 ml / l NaOH 40 g / l α, α'-bipyridyl 80 mg / l PEG 0.1 g / l [Electroless plating conditions] 70 ° C. 30 minutes at liquid temperature

(18) A commercially available photosensitive resin film (dry film) is thermocompression-bonded to the electroless copper plating film 14 and the thickness of the chromium layer in which the plating resist non-formed portion is drawn as a mask pattern A 5 mm soda lime glass substrate is contacted with the photosensitive resin film on the side on which the chromium layer is formed, and exposed at 110 mJ / cm ² , 0.8%
After developing with sodium carbonate, a pattern of a plating resist 16 having a thickness of 15 μm with L / S = 25/25 μm was provided (FIG. 3).
(b)).

(19) Next, electrolytic copper plating was performed under the following conditions to form an electrolytic copper plating film 15 having a thickness of 15 μm (FIG. 3).
(c)). [Electroplating aqueous solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (manufactured by Atotech Japan, trade name: Capparaside GL) 1 ml / l [Electroplating conditions] Current density 1.2 A / dm ² hours 30 minutes Temperature Room temperature

(20) After the plating resist 16 is removed by spraying 5% KOH, the electroless plating film 14 under the plating resist 16 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide. Then, an inner conductor circuit 9 (including via holes 17) having an L / S of 25/25 μm and a thickness of 18 μm comprising the electroless copper plating film 14 and the electrolytic copper plating film 15 was formed (see FIG. 3D). Further, Pd remaining on the roughened surface was immersed in chromic acid (800 g / l) for 1 to 10 minutes and removed.

(21) In the above (20), the conductor circuit 9 (via hole)
17 g), copper sulfate 8 g / l, nickel sulfate 0.6 g / l, citric acid 15 g / l, sodium hypophosphite 29 g / l, boric acid 31 g / l, surfactant 0.1 g /
1 was immersed in an electroless plating solution having a pH of 9 to form a roughened layer 11 made of copper-nickel-phosphorus having a thickness of 3 μm on the surface of the conductor circuit. At this time, the roughened layer 11 is
(Fluorescence X-ray analysis) showed that 98 mol% of Cu,
The composition ratio was 1.5 mol% and P 0.5 mol%. Further, the substrate is washed with water, immersed in an electroless tin displacement plating bath composed of 0.1 mol / l tin borofluoride-1.0 mol / l thiourea solution at 50 ° C. for 1 hour, and the surface of the roughened layer 11 is Thickness 0.
A tin-substituted plating layer of 05 μm was formed (however, the tin-substituted plating layer is not shown).

(22) By repeating the steps (11) to (21), an upper interlayer resin insulation layer 12b and a conductor circuit 9 (including via holes 17) are further provided to obtain a multilayer wiring board. (See FIG. 4 (a)). Here, the roughened layer 11 made of copper-nickel-phosphorus is provided on the surface of the conductor circuit, but the tin-substituted plating layer is not formed on the roughened layer surface.

(23) On the other hand, 60% by weight dissolved in DMDG
Cresol novolak epoxy resin (Nippon Kayaku)
14.6% bisphenol A type epoxy resin (manufactured by Yuka Shell Co., trade name: Epikote 1001) in which 46.67 parts by weight of a photosensitizing oligomer (molecular weight 4000) obtained by acrylate of 50% of epoxy groups of the above is dissolved in methyl ethyl ketone 15.0 Parts by weight, imidazole curing agent (Shikoku Chemicals, trade name: 2E4M
1.6 parts by weight of Z-CN), 3 parts by weight of a photosensitive acrylic monomer (manufactured by Nippon Kayaku, trade name: R604), and also a polyvalent acrylic monomer (manufactured by Kyoeisha Chemical, trade name: DP)
E6A) 1.5 parts by weight, 0.71 part by weight of a dispersion antifoaming agent (manufactured by San Nopco, trade name: S-65), and 2 parts by weight of benzophenone (manufactured by Kanto Kagaku) as a photoinitiator based on the mixture. Parts, 0.2 parts by weight of Michler's ketone (manufactured by Kanto Chemical Co., Ltd.) as a photosensitizer, and added a viscosity of 2.0 Pa ·
s was obtained. The viscosity was measured at 60 rpm using a B-type viscometer (Tokyo Keiki, DVL-B type).
In the case of No. 4, the rotor No. 4 was used, and in the case of 6 rpm, the rotor No. 3 was used.

(24) The solder resist composition was applied to both sides of the multilayer wiring board obtained in the above (22) in a thickness of 20 μm. Next, after performing a drying process at 70 ° C. for 20 minutes and a temperature of 70 ° C. for 30 minutes, a thickness 5 on which a circular pattern (mask pattern) of the solder resist opening is drawn by the chromium layer
A soda lime glass substrate having a thickness of ² mm was exposed to ultraviolet light of 1000 mJ / cm ² with the side on which the chromium layer was formed in close contact with the solder resist layer, and subjected to DMTG development treatment. In addition, at 80 ° C
Heat treatment at 100 ° C. for 1 hour, 120 ° C. for 1 hour, and 150 ° C. for 3 hours. The solder resist pattern layer 18 (opening diameter: 200 μm) with openings on the upper surface of the solder pads, via holes and lands (opening diameter: 200 μm) (Thickness: 20 μm).

(25) Next, the solder resist pattern layer 18
The substrate on which was formed was immersed in an electroless nickel plating solution having a pH of 5 consisting of 30 g / l of nickel chloride, 10 g / l of sodium hypophosphite, and 10 g / l of sodium citrate for 20 minutes, and the thickness of the opening was measured. A nickel plating layer 19 of 5 μm was formed. Further, the substrate was treated with 2 g of potassium potassium cyanide /
l, ammonium chloride 75 g / l, sodium citrate 50
A gold plating layer 20 having a thickness of 0.03 μm was formed on the nickel plating layer 19 by immersion in an electroless gold plating solution consisting of g / l and sodium hypophosphite 10 g / l at 93 ° C. for 23 seconds.

(26) Solder resist pattern layer
Solder paste (printed solder paste) was printed in the opening 18 and reflowed at 200 ° C. to form a solder bump (solder body) 21 to manufacture a multilayer printed wiring board having the solder bump 21 (see FIG. 4B). .

(Comparative Example 1) PES content: 35% by weight A multilayer printed wiring board having solder bumps was produced in the same manner as in Example 1 except that the adhesive for electroless plating was prepared as follows. [Adhesive on side (lower layer) close to substrate] 35 parts by weight of a 25% acrylate of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500), a photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315)
) 4 parts by weight, defoamer (manufactured by San Nopco, trade name: S-6)
5) 0.5 parts by weight and 3.6 parts by weight of NMP were stirred and mixed. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 14.49 parts by weight of a powder having an average particle size of 0.5 μm, and then 20 parts by weight of NMP was further added and mixed with stirring. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Was mixed with stirring. These were mixed to obtain an adhesive for electroless plating. [Adhesive on opposite side (upper layer) of substrate] 35 parts by weight of a 25% acrylate of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500), a photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315)
) 4 parts by weight, defoamer (manufactured by San Nopco, trade name: S-6)
5) 0.5 parts by weight and 3.6 parts by weight of NMP were stirred and mixed. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 7.245 parts by weight of a powder having an average particle diameter of 0.5 μm, and then 20 parts by weight of NMP was further added and mixed with stirring. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Was mixed with stirring. These were mixed to obtain an adhesive for electroless plating.

Comparative Example 2 PES amount: 10% by weight A multilayer printed wiring board having solder bumps was produced in the same manner as in Example 1 except that the adhesive for electroless plating was prepared as follows. [Adhesive on side (lower layer) close to substrate] 35 parts by weight of a 25% acrylate of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500), a photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315)
) 4 parts by weight, defoamer (manufactured by San Nopco, trade name: S-6)
5) 0.5 parts by weight and 3.6 parts by weight of NMP were stirred and mixed. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 14.49 parts by weight of a powder having an average particle size of 0.5 μm, and then 20 parts by weight of NMP was further added and mixed with stirring. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Was mixed with stirring. These were mixed to obtain an adhesive for electroless plating. [Adhesive on opposite side (upper layer) of substrate] 35 parts by weight of a 25% acrylate of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500), a photosensitive monomer (manufactured by Toa Gosei, trade name: Aronix M315)
) 4 parts by weight, defoamer (manufactured by San Nopco, trade name: S-6)
5) 0.5 parts by weight and 3.6 parts by weight of NMP were stirred and mixed. . 8 parts by weight of polyethersulfone (PES), epoxy resin particles (manufactured by Sanyo Chemicals, trade name: polymer pole)
Was mixed with 7.245 parts by weight of a powder having an average particle size of 0.5 μm, and then 20 parts by weight of NMP was further added and mixed with stirring. . Imidazole curing agent (Shikoku Chemicals, trade name: 2E4MZ-
2 parts by weight of CN), 2 parts by weight of photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure I-907), 0.2 parts by weight of photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), 1.5 parts by weight of NMP Was mixed with stirring. These were mixed to obtain an adhesive for electroless plating.

The multilayer printed wiring boards of Example 1 and Comparative Examples 1 and 2 manufactured as described above were evaluated as described below. Table 1 shows the results. (Evaluation) The peel strength was measured according to JIS-C-6481. (Evaluation) The presence or absence of resin residue at the bottom of the via hole after the roughening treatment was observed with an electron microscope.

[0079]

[Table 1]

[0080]

As described above, according to the present invention, it is possible to provide a multilayer printed wiring board which can form fine via holes and fine patterns and has excellent reliability without developing residue at the bottom of via holes. .

[Brief description of the drawings]

1 (a) to 1 (f) are views showing a part of a process for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 2A to 2E are views showing a part of a process for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 3 (a) to 3 (d) are views showing a part of a process for manufacturing a multilayer printed wiring board according to the present invention.

FIGS. 4A and 4B are diagrams illustrating a part of a process of manufacturing a multilayer printed wiring board according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Copper foil 3 Through hole 4,11 Roughened layer 5 Metal particle paste 6,14 Electroless plating film 7,15 Electrolytic plating film 8 Etching resist 9 Conductor circuit 10 Conductive layer 12a Resin filler 12b Interlayer resin insulating layer 13 Via hole opening 16 Plating resist 17 Via hole 18 Solder resist layer 19 Nickel plating layer 20 Gold plating layer 21 Solder bump (solder)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-34048 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 18/20 C09J 201/00 H05K 3 / 18 H05K 3/46

Claims (6)

(57) [Claims] 1. An adhesive for electroless plating in which cured heat-resistant resin particles soluble in an acid or an oxidizing agent are dispersed in an uncured heat-resistant resin matrix which becomes hardly soluble in an acid or an oxidizing agent by a curing treatment. In the above, the heat-resistant resin matrix is composed of a composite of a thermosetting resin and a thermoplastic resin, and the amount of the thermoplastic resin is 15 to 25% by weight based on the solid content of the heat-resistant resin matrix.
Yes , heat-resistant dispersed in the heat-resistant resin matrix
Resin particles having an average particle size of 0.1 to 1.0 μm.
And an adhesive for electroless plating. 2. A hardened heat-resistant resin particle soluble in an acid or an oxidizing agent is dispersed in a hardened heat-resistant resin matrix hardly soluble in an acid or an oxidizing agent on a substrate on which a conductive circuit is formed. The adhesive layer for electroless plating is formed, and the surface of the adhesive layer for electroless plating has a roughened surface formed by dissolving and removing the heat-resistant resin particles, and an upper layer is formed on the roughened surface. In the multilayer printed wiring board on which the conductive circuit on the side is formed, the heat-resistant resin matrix of the adhesive for electroless plating is made of a composite of a thermosetting resin and a thermoplastic resin,
The amount of the thermoplastic resin is 15 to 25% by weight based on the solid content of the heat-resistant resin matrix.
Heat-resistant resin particles dispersed in
A multilayer printed wiring board having a thickness of 0.1 to 1.0 μm . 3. The adhesive layer for electroless plating is composed of two layers, and the compounding amount of the heat-resistant resin particles in the adhesive layer for electroless plating on the substrate side is based on the solid content of the heat-resistant resin matrix. 20 to 50 wt%, claims the amount of the other heat-resistant resin particles in the adhesive layer for electroless plating is less than 20 wt% 5 wt% or more based on the solid content of the heat-resistant resin matrix 3. The multilayer printed wiring board according to 2. 4. The multilayer printed wiring board according to claim 2 , wherein said conductive circuit comprises an electroless plating film and an electrolytic plating film. 5. The multilayer printed wiring board according to claim 2 , wherein a roughened layer is formed on at least a part of the surface of the conductor circuit on the substrate. 6. The thickness of the adhesive layer for electroless plating is as follows:
The multilayer printed wiring board according to claim 2 , wherein the thickness is 45 µm or less.