JP3259906B2 - Adhesive for electroless plating and printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for electroless plating and a printed wiring board, and more particularly, to a semi-additive method capable of securing insulation reliability between wires while maintaining practical peel strength. In addition, in the full additive method, an adhesive for electroless plating that is advantageous for forming a fine pattern and that can guarantee insulation reliability between wires under high temperature and high humidity conditions while maintaining practical peel strength;
This is a proposal for a printed wiring board using this adhesive.

[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, an interlayer resin insulating layer made of a photosensitive electroless plating adhesive is applied on the core substrate, dried, exposed and developed to form an interlayer resin insulating layer having a via hole opening. Then, after the surface of the interlayer resin insulating layer is roughened by treatment with an oxidizing agent or the like, a plating resist obtained by exposing and developing a photosensitive resin layer on the roughened surface is provided. A conductive circuit pattern including via holes is formed by applying electroless plating to the non-resist-formed portions, and such a process is repeated a plurality of times to obtain a multi-layered build-up wiring board by the additive method.

In a build-up wiring board manufactured by such a method, as an adhesive for electroless plating used for an interlayer resin insulating layer, JP-A-63-158156 and JP-A-2-188992 ( (USP5055321, USP5519177)
As described in the above, in the heat-resistant resin matrix which becomes hardly soluble by the curing treatment, the soluble cured resin particles comprising coarse particles having an average particle diameter of 2 to 10 μm and fine particles having an average particle diameter of 2 μm or less are hardened. Some are dispersed. Also, JP-A-61-276875 (USP4752499, USP50214)
No. 72) discloses an adhesive for electroless plating in which a dissolvable cured epoxy resin powder crushed to an average particle size of 1.6 μm is dispersed in a hardly soluble heat-resistant resin matrix.

The surface of the interlayer resin insulation layer formed on the substrate using these adhesives is roughened by dissolving and removing the heat-resistant resin particles present on the surface layer. Excellent adhesion to conductor circuits formed via plating resist.

However, a build-up wiring board in which a plating resist remains as a permanent resist, such as a wiring board manufactured by the full additive method, has poor adhesion at the interface between the permanent resist and the conductor circuit. For this reason, when this build-up wiring board is mounted with an IC chip, there is a problem that cracks originating from the interface between the plating resist and the conductive circuit are generated in the interlayer resin insulating layer due to a difference in thermal expansion coefficient between the plating resist and the conductive circuit. there were.

Conventionally, as a technique for preventing cracks generated in an interlayer resin insulating layer, a plating resist is removed to roughen at least a side surface of a conductive circuit, thereby forming an interlayer formed on the conductive circuit. A method for improving the adhesion to a resin insulating layer has been proposed. As a method for manufacturing a wiring board to which this method can be advantageously applied, there is a semi-additive method.

In the semi-additive method, first, the surface of an interlayer resin insulating layer is roughened, electroless plating is thinly applied on the entire roughened surface, and then a plating resist is applied to a non-conductive portion of the electroless plated film. This is a method of forming a conductive circuit pattern by forming, applying a thick electrolytic plating to a portion where the resist is not formed, and removing the plating resist and the electroless plating film under the plating resist.

However, in the build-up wiring board manufactured by the semi-additive method manufactured using the above-mentioned adhesive, the electroless plating film remains in the depression (anchor) of the roughened surface of the adhesive layer under the resist, There is a problem that the insulation reliability between the wires is reduced.

Also, the build-up wiring board manufactured by the full additive method using the above-mentioned adhesive has a problem that the insulation resistance value between the conductor circuits is reduced under the condition of high temperature and high humidity.

Further, in any case, the wiring board manufactured by the full-additive method or the semi-additive method may break the interlayer insulation if the adhesive contains relatively large heat-resistant resin particles having an average particle diameter of 2 μm or more. Had the problem of doing so.

[0011]

SUMMARY OF THE INVENTION The present invention proposes a technique for solving the problem of the wiring board manufactured by the full additive method or the semi-additive method described above. A main object of the present invention is to provide an adhesive for electroless plating which is advantageous for maintaining practical peel strength and ensuring insulation reliability between wires and between layers. Another object of the present invention is to provide a printed wiring board having excellent reliability using the above-mentioned adhesive for electroless plating.

[0012]

Means for Solving the Problems The inventor of the present invention has intensively studied to realize the above object. As a result, it is considered that the above-mentioned problem occurs because the average particle size of the heat-resistant resin particles to be dissolved and removed is too large, and the following knowledge was obtained. That is, the interlayer resin insulating layer made of the above-mentioned adhesive in which dissolvable resin particles composed of coarse particles having an average particle diameter of 2 to 10 μm and fine particles having an average particle diameter of 2 μm or less are dispersed in a hardly heat-resistant resin matrix. The depth of the depression (anchor) of the roughened surface formed on the surface of the layer is about 10 μm (for example, Example 1 of JP-A-7-34048 (US Pat. No. 5,519,177)). For this reason, in the semi-additive method, the electroless plating film is formed to the deep portion of the depression, and the electroless plating film is not completely removed by etching, and is considered to decrease the line insulation. Can be On the other hand, in the full-additive method, the deeper the roughened surface is, the larger the surface area becomes, and a large number of palladium, which is the catalyst nucleus of the electroless plating film, adheres under the plating resist between the wires. As a result, it is considered that the palladium reacts with chlorine ions or the like in the heat-resistant resin under a high-temperature and high-humidity condition to form a conductive compound, thereby deteriorating insulation properties between wires. Further, when heat-resistant resin particles having an average particle diameter of 2 μm or more are present in the interlayer resin insulating layer, voids are easily generated between the layers due to the roughening treatment, and a plating film is deposited in the voids to form an upper layer and a lower layer. It is considered that the conductive circuits are electrically connected and the interlayer insulation is broken.

The inventor has developed an electroless plating adhesive having the following features based on such knowledge. (1) The adhesive for electroless plating of the present invention is a cured heat-resistant resin particle which is soluble in an acid or an oxidizing agent in an uncured heat-resistant resin matrix which becomes hardly soluble in an acid or an oxidizing agent by the curing treatment. In the adhesive for electroless plating obtained by dispersing, the heat-resistant resin particles have an average particle diameter of
1.5μm or less, more preferably in the 0.1~1.0μm, deer
Also has a maximum particle size of less than 2 μm and a peak in its particle size distribution
Distribution such that the particle size in the
Characterized in that it is intended to have.

[0014] Here, the heat-resistant resin particles is preferably spherical particles, it is preferable that the peak of the particle size distribution is one.

Further, the printed wiring board of the present invention has the following configuration. (2) On a printed wiring board having a surface-roughened hardened electroless plating adhesive layer having a roughened surface and a conductive circuit formed on the roughened surface of the adhesive layer surface. The adhesive layer is formed by dispersing cured heat-resistant resin particles soluble in an acid or an oxidizing agent in an uncured heat-resistant resin matrix that becomes hardly soluble in an acid or an oxidizing agent by a curing treatment. Consisting of an adhesive for plating and
Roughened surface of the layer, the depth R _max of the depression that is it the 1~5μm
It is roughened so that, the heat-resistant resin particles of the adhesive has an average particle size of 1.5μm or less, more preferably 0.1 to 1.
0 μm, the maximum particle size is less than 2 μm, and its particle size distribution
So that the particle size at the peak of
It has a characteristic distribution .

[0016] Here, the heat-resistant resin particles are preferably rather preferable to be spherical particles, the peak of the particle size distribution is one. The conductor circuit formed on the roughened surface of the adhesive layer surface is preferably constituted by an electroless plating film and an electrolytic plating film, and the conductor circuit has a rough surface on at least a part of the surface. It is preferable that the oxide layer is formed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the case of the semi-additive method, as described above, it is necessary to dissolve and remove the electroless plating film under the plating resist. Therefore, if the depression on the roughened surface is deep, the electroless plating film tends to remain in the depression,
This causes the insulation resistance between lines to decrease. on the other hand,
If the depression has a simple shape and is shallow, the peel strength of the plating film is reduced, and the conductor is easily peeled. In the case of the full additive method, as described above, since the palladium catalyst remains under the plating resist, if the depression on the roughened surface is deep, the insulation resistance between the wires decreases under high-temperature and high-humidity conditions. On the other hand, when the depression is simple and shallow, the peel strength of the plating film is reduced and the conductor is liable to peel off, as in the case of the semi-additive method.

In this respect, the adhesive for electroless plating of the present invention is a heat-resistant resin particle having an average particle size of 1.5 μm or less.
I, is characterized by comprising a heat-resistant resin particles having a distribution as the particle diameter at the peak of the particle size distribution is at the following areas 1.5 [mu] m. This prevents deepening of the pits on the roughened surface due to dissolution of the resin particles having a large particle diameter (shallowing the dents on the roughened surface), and dissolving residues of the electroless plating film in the pits. Eliminating or reducing the amount of palladium catalyst under the plating resist ensures the reliability of insulation between lines and between layers while maintaining practical peel strength even on roughened surfaces with shallow depressions. .

[0019] That is, in the adhesive for electroless plating of the present invention, the heat-resistant resin particles have an average particle size of at 1.5μm or less, so that the particle diameter at the peak of the particle size distribution is at the following areas 1.5 [mu] m Since there is no distribution, there is no resin particles having a large particle size as in the prior art, the depth of the dent to be formed by being dissolved and removed is shallow, and the roughening does not proceed too much and does not generate voids . Therefore, a printed wiring board manufactured using the adhesive containing the heat-resistant resin particles has excellent interlayer insulating properties.

Further, it is surprising that a printed wiring board manufactured using an adhesive containing such heat-resistant resin particles can maintain a practical peel strength even if the depression on the roughened surface is shallow. I found the facts. For example, in the case of the full additive method, a photosensitive resin layer provided on a roughened surface for forming a plating resist is exposed and developed to form a plating resist. Therefore, when the depression on the roughened surface is deep, the development residue of the plating resist easily occurs in the depression. In this regard, in the present invention, the recess formed is shallow, and the resist in the recess can be easily developed, so that the development residue of the plating resist is less likely to occur, and the reduction in peel strength is relatively small even if the recess is made shallow. is there. On the other hand, in the case of the semi-additive method, since the electroless plating film is formed directly on the roughened surface, the plating resist does not remain in the dents on the roughened surface. Is relatively small.

The opening for forming the via hole is exposed,
In the case of forming by development processing or laser processing, the adhesive for electroless plating remains as a residue at the bottom of the opening for forming the via hole. In this regard, in the present invention, the heat-resistant resin particles having an average particle size of 1.5 μm or less (preferably, an average particle size of 0.1 to 1.0 μm) soluble in an acid or an oxidizing agent are present in the adhesive for electroless plating. Therefore, such a residue can be easily removed by a roughening treatment with an acid or an oxidizing agent, and there is no need to separately form a layer for removing the residue under the adhesive layer. Moreover, in the present invention, since the recess formed is shallow,
Regardless of whether the semi-additive method or the full-additive method is employed, the line spacing / line width (hereinafter simply referred to as L / S
= 40/40 µm.

The heat-resistant resin particles according to the present invention are preferably not spherical particles but spherical particles. The reason is that if the heat-resistant resin particles are crushed particles,
This is because the concave shape of the roughened surface is angular, and stress concentration is likely to occur at the corner, and cracks are likely to occur from the corner due to heat cycles.

The heat-resistant resin particles have an average particle diameter of 0.1 to
Preferably it is 1.0 μm. The reason is that when the average particle size is within this range, the depth of the depression formed by dissolving and removing the heat-resistant resin particles is approximately Rmax = about 3 μm. As a result, in the semi-additive method, not only can the electroless plating film of the non-conductor portion be easily removed by etching, but also the Pd catalyst nucleus under the electroless plating film can be easily removed, and the peel strength of the conductor portion can be improved. Is maintained at a practical level of 1.0 to 1.3 kg / cm. On the other hand, in the full additive method, not only can the amount of Pd catalyst nuclei under the plating resist be reduced, but also the plating resist residue in the conductor portion can be eliminated, so that even a shallow depression has a practical peel strength of 1.0 to 1.3.
This is because it can be maintained at kg / cm.

The heat-resistant resin particles have a particle size at the peak of the particle size distribution of 1.5 μm or less, more preferably
It is desirable that the distribution has a distribution in the range of 0.1 to 1.0 μm. In particular, when the particle size at the peak of the particle size distribution is in the range of 0.1 to 1.0 μm, the standard deviation is desirably 0.5 or less. By adjusting to such a particle size distribution, the constituent particles of the heat-resistant resin particles are less than 2 μm , that is, the maximum particle size is 2 μm , and it is possible to completely remove the influence of the resin particles having a large particle size as in the conventional technology. it can.

Here, the particle size distribution of the heat-resistant resin particles is measured by a laser diffraction / scattering method. The measurement principle of the laser diffraction / scattering method will be described below. First, by irradiating a laser beam to a particle to be measured, a light intensity distribution pattern of diffracted / scattered light is generated spatially. This light intensity distribution pattern changes depending on the size of the particles. That is, there is a one-to-one relationship between the particle size and the light intensity distribution pattern, and if the light intensity distribution pattern is known, the particle size can be specified. The actual sample is a particle group consisting of many particles. Therefore, the light intensity distribution pattern is a superposition of diffraction / scattered light from each particle.
The particle size distribution of the sample particle group is determined by calculation from the light intensity distribution pattern of the overlap. In addition, as a measuring device using such a laser diffraction / scattering method, there are "Shimadzu laser diffraction type particle size distribution measuring device SALD-2000 / SALD-2000A" and "Shimadzu laser diffraction type particle size distribution measuring device SALD" manufactured by Shimadzu Corporation. −3000 ”.

The particle size distribution thus obtained includes, for example,
As shown in FIG. 25 and FIG. 26, there is a graph showing the relationship between the particle diameter and the abundance ratio (abundance) of the resin particles showing the particle diameter.
Here, the peak of the particle size distribution means a point where the abundance ratio (amount) of the resin particles is maximized.

In the present invention, the heat-resistant resin particles preferably have a single particle size distribution peak. That is, the case where the maximum value of the abundance ratio (amount) of the resin particles is one. With such a particle size distribution, light scattering due to the particle size distribution can be suppressed, so that the development residue is reduced. Further, it is possible to provide a printed wiring board which is easy to manage products, hardly causes variation in characteristics such as peel strength, and is excellent in mass productivity. The particle size distribution is adjusted by using a centrifugal separation method, an air classification method, a sieve, or the like.

In the adhesive for electroless plating of the present invention,
The mixing ratio of the heat-resistant resin particles is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the solid content of the heat-resistant resin matrix. The reason for this is that if the content of the resin particles is too large, the roughening proceeds too much and the interlayer insulation is liable to break down, and a problem occurs such that a clear roughened surface cannot be formed. Is too small to form a clear roughened surface.

Further, in the adhesive for electroless plating of the present invention, it is necessary that the heat-resistant resin particles are cured beforehand. If it is not cured, it will be dissolved in a solvent that dissolves the resin matrix and will be uniformly mixed, and it will not be possible to selectively dissolve and remove only the heat-resistant resin particles with an acid or an oxidizing agent.

In the adhesive for electroless plating of the present invention,
As the heat-resistant resin matrix, a thermosetting resin (including one in which some or all of the thermosetting groups are sensitized) or a thermosetting resin (including one in which some or all of the thermosetting groups are sensitized) ) And a thermoplastic resin. Here, an epoxy resin, a phenol resin, a polyimide resin, or the like can be used as the thermosetting resin. When part or all of the thermosetting group is sensitized, a part of the thermosetting group is reacted with methacrylic acid, acrylic acid, or the like to be acrylated. Of these, epoxy resin acrylate is most suitable. As the epoxy resin, a novolak type epoxy resin, an alicyclic epoxy resin, or the like can be used. As a curing agent, 25
It is preferably a liquid at ℃. Specifically, 1-benzyl-2-
Methylimidazole (1B2MZ), 1-cyanoethyl-2-methylimidazole (2E4MZ-CN),
A liquid imidazole curing agent such as 4-methyl-2-ethylimidazole (2E4MZ) can be used. Examples of the thermoplastic resin include polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, and polyether imide. The amount of the thermoplastic resin is preferably less than 30% by weight based on the total solid content of the resin matrix, more preferably
10 to 25% by weight. The reason is that at 30% by weight or more,
This is because the thermoplastic resin remains at the bottom of the via-hole opening, and the via-hole and the inner-layer conductor circuit are likely to be separated due to poor conduction, a heating test, or the like. When an organic solvent is used, examples of the organic solvent include glycol ether solvents having the following structural formulas such as diethylene glycol dimethyl ether (DMDG) and triethylene glycol dimethyl ether (DMTG), and N-methylpyrrolidone (NMP). It is desirable to use such as. CH ₃ O— (CH ₂ CH ₂ O) _n —CH ₃ (n = 1 to
5)

In the adhesive for electroless plating of the present invention,
Amino resin (melamine resin,
Urea resin, guanamine resin, etc.), epoxy resin, bismaleimide-triazine resin and the like can be used. The epoxy resin can be arbitrarily prepared to be soluble in an acid or an oxidizing agent or to be hardly soluble by appropriately selecting the type of oligomer, the type of curing agent, and the like. For example, a resin obtained by curing a bisphenol A-type epoxy oligomer with an amine-based curing agent is very soluble in chromic acid, whereas a resin obtained by curing a cresol novolak-type epoxy oligomer with an imidazole curing agent is not easily dissolved in chromic acid.

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

Next, a printed wiring board using the adhesive for electroless plating of the present invention has a hardened, electroless plating adhesive layer having a roughened surface on a substrate. In a printed wiring board in which a conductive circuit is formed on a roughened surface of a surface of an agent layer, the adhesive layer contains an acid or an uncured heat-resistant resin matrix which becomes hardly soluble in an acid or an oxidizing agent by a curing treatment. It consists of an adhesive for electroless plating which is obtained by dispersing cured heat-resistant resin particles soluble in an oxidizing agent, and the heat-resistant resin particles have an average particle size of 1.5 μm.
m, more preferably 0.1 to 1.0 μm.

In the printed wiring board of the present invention, it is preferable that the heat-resistant resin particles have such a distribution that the particle size at the peak of the particle size distribution falls within a region of 1.5 μm or less. As a result, the adhesive layer of the printed wiring board according to the present invention does not have resin particles having a large particle diameter as in the related art, and the depth of the recess formed by being dissolved and removed is shallow, and the roughening proceeds excessively. Gaps are not generated. Therefore, the printed wiring board of the present invention having the adhesive layer containing the heat-resistant resin particles has excellent interlayer insulation properties. Moreover, the printed wiring board of the present invention can maintain a practical peel strength even if the depression on the roughened surface is shallow.

Further, in the printed wiring board of the present invention,
The heat-resistant resin particles preferably have one particle size distribution peak. That is, the abundance ratio (amount) of the resin particles
Is the maximum value of one. With such a particle size distribution, light scattering due to a difference in particle diameter can be suppressed, and thus the development residue is reduced. As a result, the wall shape of the opening for the via hole is also improved.

In the printed wiring board according to the present invention, the roughened surface of the adhesive layer surface has a depth of R _max.
= 1 to 5 µm. The depth of this depression is determined by the depth Rma of the depression on the roughened surface formed by the conventional adhesive.
x = approximately の of 10 μm, which is a range in which no plating film remains even when the electroless plating film under the plating resist is dissolved and removed, and the amount of palladium catalyst nuclei under the plating resist can be reduced.

The thickness of the adhesive layer for electroless plating is as follows:
The thickness is less than 50 μm, preferably 15 to 45 μm. When the thickness of the adhesive layer is reduced to less than 50 μm, the heat-resistant resin particles in the adhesive layer communicate with each other and dielectric breakdown between the layers is likely to occur. In this regard, in the present invention, since the heat-resistant resin particles have a fine particle diameter, such destruction hardly occurs. Further, it is desirable that a via hole having a diameter of less than 100 μm is formed in the adhesive layer for electroless plating. When forming a small-diameter via hole, development residue tends to occur. In this regard, in the present invention, since the adhesive containing fine heat-resistant resin particles is used, it is easy to remove the development residue. Moreover,
When forming a small diameter via hole, if the adhesive contains large particles, the via hole diameter becomes large due to roughening. Also in this respect, the adhesive containing fine heat-resistant resin particles as in the present invention is advantageous.

In the printed wiring board of the present invention, in the semi-additive method, the conductive circuit formed on the roughened surface of the adhesive layer surface is composed of a thin electroless plating film and a thick electrolytic plating film. It is preferred that By adopting the above configuration in which the electrolytic plating film having a small plating stress is thickened, the plating film does not peel even if the depression on the roughened surface is shallow.

[0039]

Furthermore, it is preferable that the conductor circuit formed on the roughened surface of the adhesive layer surface has a roughened layer formed on at least a part of the surface, that is, on the upper surface, the side surface, or the entire surface. 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 the printed wiring board according to the present invention by a semi-additive and a full-additive method will be specifically described. [Semi-additive method] (1) In order to manufacture a multilayer wiring board by the semi-additive method, first, a wiring board having a conductor circuit formed on the surface of the board is manufactured. As this substrate, a resin insulating substrate such as a glass epoxy substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a ceramic substrate, a metal substrate, or the like can be used. The conductor circuit of this wiring board is formed by etching a copper-clad laminate, or by forming an adhesive layer for electroless plating on a substrate such as a glass epoxy substrate, a polyimide substrate, a ceramic substrate, or a metal substrate, and bonding the substrate. A method in which the surface of the agent layer is roughened to a roughened surface and electroless plating is performed thereon, or a so-called semi-additive method (a thin electroless plating is applied to the entire roughened surface, a plating resist is formed, and a plating resist is removed. After a thick electrolytic plating is applied to the formation portion, a plating resist is removed, an etching process is performed, and a conductive circuit including an electrolytic plating film and an electroless plating film is formed.

[0042]

[0043]

Further, a through hole is formed in the core substrate, and the wiring layer on the front surface and the back surface can be electrically connected through the through hole. Further, a low-viscosity resin such as a bisphenol F-type epoxy resin may be filled between the through-holes and the conductor circuit of the core board to ensure the smoothness of the wiring board.

(2) Next, an interlayer resin insulating agent is applied on the wiring board prepared in the above (1). As the interlayer resin insulating material, the adhesive for electroless plating of the present invention is used. At this time, a roll coater, a curtain coater, or the like can be used for applying the interlayer resin insulating agent. Note that the interlayer resin insulating layer may have a plurality of layers, and the particle diameter of the heat-resistant resin particles in each layer may be changed. For example, the average particle size of the lower heat-resistant resin particles
0.5μm, the average particle size of the heat-resistant resin particles in the upper layer is 1.0μ
m may be composed of an adhesive for electroless plating in which heat-resistant resin particles have different particle diameters. In particular, the heat-resistant resin particles in the lower layer have an average particle size of 0.1 to 2.0 μm, more preferably 0.1 to 1.0 μm.

Here, the heat-resistant resin matrix constituting the lower adhesive layer may be a thermosetting resin, a thermosetting resin (including those obtained by sensitizing a part or all of the thermosetting group), or a thermosetting resin. A composite of a curable resin (including one obtained by sensitizing a part or all of the thermosetting group) and a thermoplastic resin can be used. As the thermosetting resin constituting the lower adhesive layer, an epoxy resin, a phenol resin, a polyimide resin, or the like can be used. In the case where a part of the thermosetting group is made photosensitive, a part of the thermosetting group is reacted with methacrylic acid, acrylic acid, or the like to be acrylated.
Of these, epoxy resin acrylate is most suitable. As this epoxy resin, novolak type epoxy resin,
An alicyclic epoxy resin can be used. As the thermoplastic resin constituting the lower adhesive layer, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, or the like can be used.
As the heat-resistant resin particles constituting the lower adhesive layer, amino resin (melamine resin, urea resin, guanamine resin, etc.), epoxy resin, bismaleimide-triazine resin, and the like can be used.

(3) The applied interlayer resin insulating agent (adhesive for electroless plating) is dried. At this time, the interlayer resin insulation layer provided on the conductor circuit of the substrate has a thin interlayer resin insulation layer on the conductor circuit pattern and a thick interlayer resin insulation layer on the conductor circuit having a large area. In many cases, the unevenness occurs. Therefore, it is desirable that the interlayer resin insulating layer in the uneven state is pressed while being heated using a metal plate or a metal roll to flatten the surface of the interlayer resin insulating layer.

(4) Next, while the interlayer resin insulating layer is cured, an opening for forming a via hole is provided in the interlayer resin insulating layer. The curing treatment of the interlayer resin insulating layer is performed by thermosetting when the resin matrix of the adhesive for electroless plating is a thermosetting resin, and is performed by exposing with a UV ray or the like when the resin matrix is a photosensitive resin. Openings for forming via holes are perforated using laser light or oxygen plasma if the resin matrix of the adhesive for electroless plating is a thermosetting resin, or exposed and developed if the resin matrix is a photosensitive resin. Pierced. In the exposure and development process, a photomask (preferably a glass substrate) on which a circular pattern for forming a via hole is drawn is placed on the photosensitive interlayer resin insulating layer with the circular pattern side in close contact with the photomask. , Exposure and development processing.

(5) Next, the surface of the interlayer resin insulating layer (adhesive layer for electroless plating) provided with openings for forming via holes is roughened. In particular, in the present invention, the surface of the adhesive layer is roughened by dissolving and removing the heat-resistant resin particles present on the surface of the adhesive layer for electroless plating with an acid or an oxidizing agent. At this time, the depth of the depression on the roughened surface is preferably about 1 to 5 μm. Here, examples of the acid include phosphoric acid, hydrochloric acid, sulfuric acid, and organic acids such as formic acid and acetic acid.
In particular, it is desirable 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. On the other hand, it is desirable to use chromic acid and permanganate (such as potassium permanganate) as the oxidizing agent.

(6) Next, a catalyst nucleus is applied to 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.
Use palladium chloride or palladium colloid. Note that it is desirable to perform a heat treatment to fix the catalyst core. Palladium is preferred as such a catalyst core.

(7) Next, a thin electroless plating film is formed on the entire surface of the roughened interlayer resin insulating layer. The electroless plating film is preferably an electroless copper plating film, and its thickness is 1 to
5 μm, more preferably 2-3 μm. In addition, as the electroless copper plating solution, those having a liquid composition adopted in a usual manner can be used. For example, copper sulfate: 29 g / l, sodium carbonate: 25 g / l, tartrate: 140 g / l, sodium hydroxide : 40 g / l, 37% formaldehyde: 150 ml, (p
H = 11.5).

(8) Next, a photosensitive resin film (dry film) is laminated on the electroless plating film provided in the above (7), and a photo resist pattern is drawn on the photosensitive resin film. A mask (preferably a glass substrate) is placed in close contact with the mask, and exposed and developed to form a non-conductive portion on which a plating resist pattern is provided.

(9) Next, an electrolytic plating film is formed on a portion other than the non-conductor portion on the electroless plating film, and a conductor circuit and a conductor portion serving as a via hole are provided. Here, it is desirable to use electrolytic copper plating as the electrolytic plating, and its thickness is preferably 10 to 20 μm.

(10) Next, after removing the plating resist of the non-conductive portion, a mixed solution of sulfuric acid and hydrogen peroxide or etching of sodium persulfate, ammonium persulfate, ferric chloride, cupric chloride, etc. is further performed. The electroless plating film is dissolved and removed with the solution to obtain an independent conductor circuit including two layers of the electroless plating film and the electrolytic plating film, and a via hole. In addition,
The palladium catalyst core on the roughened surface exposed to the non-conductive part
Dissolve and remove with chromic acid.

(11) Next, a roughened layer is formed on the surface of the conductor circuit obtained in (10) and the via hole. As a method for forming the roughened layer, there are an etching treatment, a polishing treatment, an oxidation-reduction treatment and a plating treatment. The oxidation-reduction treatment is performed by using NaOH (10 g / l) and NaClO ₂ as an oxidation bath (blackening bath).
(40 g / l), Na ₃ PO ₄ (6 g / l), and NaOH (10 g / l) and NaBH ₄ (5 g / l) as a reducing bath. When forming a roughened layer of a copper-nickel-phosphorus alloy layer, it is deposited by electroless plating. Electroless plating solutions for this alloy include copper sulfate 1-40 g / l, nickel sulfate 0.1-6.0 g / l, citric acid 10-20 g / l, hypophosphite 10-100 g / l, boric acid 10-g. It is desirable to use a plating bath having a liquid composition of 40 g / l and a surfactant of 0.01 to 10 g / l.

(12) Next, an interlayer resin insulation layer is formed on the substrate according to the steps (2) and (3). (13) If necessary, the steps (4) to (10) are repeated to form a multilayer, thereby manufacturing a multilayer wiring board.

[Full Additive Method] (1) First, using the adhesive for electroless plating of the present invention, the steps (1) to (6) are carried out in the same manner as in the semi-additive method. (2) Next, on the roughened surface of the interlayer resin insulating layer (adhesive layer for electroless plating) to which the catalyst nucleus has been applied, a non-conductive portion provided with a plating resist pattern is formed. The plating resist is formed by a method of laminating a commercially available photosensitive dry film and exposing and developing, or a method of applying a liquid plating resist composition with a roll coater and drying, exposing and developing. As the plating resist composition, a photosensitive resin composition comprising a resin obtained by acrylizing a novolak type epoxy resin such as a cresol novolak type epoxy resin or a phenol novolak type epoxy resin with methacrylic acid or acrylic acid and an imidazole curing agent is used. It is desirable. The reason is that such a photosensitive resin composition is excellent in resolution and base resistance.

(3) Next, electroless plating is applied to portions other than the non-conductor portion (plating resist portion) to provide a conductor circuit and a conductor portion serving as a via hole. Electroless plating is preferably electroless copper plating. When filling the via hole forming opening with electroless plating to form a so-called filled via, first, before applying the catalyst nucleus on the electroless plating adhesive layer, the via hole forming opening is formed. The surface of the lower conductive layer exposed from the surface is treated with an acid to activate and dipped in an electroless plating solution. Then, after filling the opening for via hole formation by electroless plating, a catalyst nucleus is provided on the adhesive layer for electroless plating, and a plating resist is provided,
A conductor layer is provided by performing electroless plating. In the via hole formed by filling with such an electroless plating film, another via hole can be formed directly above the via hole, so that the diameter and the density of the wiring board can be reduced. Further, as means for improving the adhesion between the conductor layer and the adhesive layer for electroless plating, alloy plating using at least two or more metal ions selected from copper, nickel, cobalt and phosphorus is used as primary plating. After that, there is a method of applying copper plating as secondary plating. This is because these alloys have high strength and can improve peel strength.

(4) Next, a roughened layer is formed on the upper surface of the conductor circuit and the via hole formed other than the plating resist portion. As a method for forming the roughened layer, there are an etching treatment, a polishing treatment, an oxidation-reduction treatment and a plating treatment. In addition, when forming a roughened layer by a copper-nickel-phosphorus alloy layer, it is deposited by electroless plating.

(5) Further, if necessary, an upper interlayer insulating layer (adhesive layer for electroless plating) and a conductor layer are laminated to form a multilayer, thereby producing a multilayer wiring board.

[0061]

【Example】

(Example 1) Semi-additive method 0.5 μm (1) Both sides of a substrate 1 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 0.6 mm are coated with 18
A copper-clad laminate obtained by laminating a μm copper foil 8 was used as a starting material (see FIG. 1). First, the copper-clad laminate was drilled, subjected to electroless plating, and etched in a pattern to form inner layer conductor circuits 4 and through holes 9 on both surfaces of the substrate 1. The surfaces of the inner layer conductor circuit 4 and the through hole 9 are roughened by oxidation (blackening) -reduction treatment (see FIG. 2), and a bisphenol F type epoxy resin is filled as a filling resin 10 between the conductor circuits and in the through hole. After that (see FIG. 3), the substrate surface was polished and flattened until the conductor circuit surface and the land surface of the through hole were exposed (see FIG. 4).

(2) After the substrate subjected to the treatment of (1) is washed with water and dried, the substrate is acid-degreased and soft-etched, and then treated with a catalyst solution comprising palladium chloride and an organic acid. , A Pd catalyst, and after activating this catalyst, 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, interface Plating is performed in an electroless plating bath consisting of activator 0.1 g / l and pH = 9, and a 2.5 μm thick roughened layer made of Cu-Ni-P alloy is formed on the exposed surface of the copper conductor circuit.
11 (uneven layer) was formed. In addition, the substrate is
/ L tin borofluoride-1.0 mol / l immersion in an electroless tin displacement plating bath consisting of a thiourea solution at 50 ° C for 1 hour to form a 0.3 μm thick tin displacement plating layer on the surface of the roughened layer 11. (See FIG. 5, but the tin layer is not shown).

(3) 34 parts by weight of 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether), 12 parts by weight of polyether sulfone (PES), imidazole curing (Shikoku Chemicals, trade name: 2E4M
2 parts by weight of Z-CN), 4 parts by weight of caprolactone-modified tris (acroxyethyl) isocyanurate (trade name, manufactured by Toagosei Co., Ltd., Aronix M315), a photoinitiator (trade name: Irga, manufactured by Ciba Geigy) Cure 90
7) 2 parts by weight, photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-
S) 0.2 part by weight, epoxy resin particles (manufactured by Sanyo Chemical Industries, trade name: Polymerpole S-301), and the particle size distribution of the particles is shown in Fig. 25. The average particle diameter of the particles is the median diameter
0.51 μm with a standard deviation of 0.193. This particle
It is distributed in the range of 0.09 μm to 1.32 μm, and the particle size at the peak of the particle size distribution is 0.58 μm. As is clear from FIG. 25, there is one peak. The particle size distribution was measured using a Shimadzu laser diffraction particle size distribution analyzer: SALD-2000, manufactured by Shimadzu Corporation. ) Were mixed with 30.0 parts by weight of NMP (normal methylpyrrolidone), and the mixture was mixed with a homodisper stirrer to give a viscosity of 7 parts.
The mixture was adjusted to Pa · s, and then kneaded with three rolls to obtain a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent).

(4) The photosensitive adhesive solution obtained in the above (3) is applied to both surfaces of the substrate after the treatment in the above (2) using a roll coater and left in a horizontal state for 20 minutes. And then 60
Drying was performed at 30 ° C. for 30 minutes to form an adhesive layer 2 having a thickness of 60 μm (see FIG. 6).

(5) A polyethylene terephthalate film (translucent film) was adhered to the adhesive layer 2 formed on both sides of the substrate in the above (4) via an adhesive. And
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 with a light-shielding ink having a thickness of 5 μm is placed with the side on which the circular pattern is drawn in close contact with the adhesive layer 2. Then, exposure was performed by irradiating ultraviolet rays.

(6) The exposed substrate was spray-developed with a DMTG (triethylene glycol dimethyl ether) solution to form an opening in the adhesive layer 2 as a 100 μmφ via hole. 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 a heat treatment at 150 ° C. for 5 hours, an adhesive layer 2 having a thickness of 50 μm having openings (openings for forming via holes) 6 having excellent dimensional accuracy corresponding to a photomask film.
Was formed. Note that the roughened layer 11 was partially exposed in the opening 6 serving as a via hole (see FIG. 7).

(7) The substrate having the via hole forming openings 6 formed in the above (5) and (6) is immersed in chromic acid for 2 minutes to dissolve and remove the epoxy resin particles present on the surface of the adhesive layer 2. Then, the surface of the adhesive layer 2 was roughened, and then immersed in a neutralizing solution (manufactured by Shipley) and washed with water (see FIG. 8).

(8) The surface roughening treatment (roughening depth 5 μm)
By applying a palladium catalyst (manufactured by Atotech) to the substrate subjected to m), catalyst nuclei were provided on the surfaces of the adhesive layer 2 and the via hole openings 6.

(9) The substrate was immersed in an electroless copper plating bath having the following composition to form a 3 μm-thick electroless copper plating film 12 on the entire rough surface (see FIG. 9). [Electroless plating 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

(10) Electroless copper plating film formed in (9)
A commercially available photosensitive resin film (dry film) is thermocompression-bonded onto the substrate 12, and a 5 mm-thick soda lime on which a plating resist non-formed portion is drawn as a mask pattern by a chrome layer on the dry film. A glass substrate is placed on the dry film with the chromium layer formed side in close contact with the dry film, exposed at 110 mJ / cm ² , developed with 0.8% sodium carbonate, and patterned with a 15 μm thick plating resist 3. (See FIG. 10).

(11) Next, in the portion where the plating resist is not formed,
Electrolytic copper plating was performed under the following conditions to form an electrolytic copper plating film 13 having a thickness of 15 μm (see FIG. 11). [Electroplating solution] Sulfuric acid 180 g / l Copper sulfate 80 g / l Additive (trade name: Capparaside GL, manufactured by Atotech Japan) 1 ml / l [Electroplating conditions] Current density 1.2 A / dm ² hours 30 minutes Temperature Room temperature

(12) After the plating resist 3 is removed by spraying with 5% KOH, the electroless plating film 12 under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide. Then, an 18 μm thick inner conductor circuit 5 composed of the electroless copper plating film 12 and the electrolytic copper plating film 13 was formed. Further, Pd remaining on the roughened surface 11 is replaced with chromic acid (800
g / l) for 1 to 2 minutes to remove (see FIG. 12).

(13) The substrate on which the conductor circuit 5 is formed is made of copper sulfate 8 g / l, nickel sulfate 0.6 g / l, citric acid 15 g / l
1, sodium hypophosphite 29 g / l, boric acid 31 g / l,
The surface of the conductor circuit 5 was immersed in an electroless plating solution having a pH of 9 containing 0.1 g / l of a surfactant to form a roughened layer 11 made of copper-nickel-phosphorus having a thickness of 3 μm. At this time,
When the roughened layer 11 was analyzed by EPMA (X-ray fluorescence spectrometer), the composition ratio was 98 mol% of Cu, 1.5 mol% of Ni, and 0.5 mol% of P. Then, further rinse the board with water,
ol / l tin borofluoride-1.0 mol / l immersed in an electroless tin displacement plating bath composed of a thiourea solution at 50 ° C. for 1 hour to form a 0.3 μm thick tin displacement plating layer on the surface of the roughened layer 11. This was formed (see FIG. 13; however, a tin-substituted layer was not shown).

(14) Next, the adhesive layer 2 is further provided in accordance with the step (4), a polyethylene terephthalate film (light-transmitting film) is adhered to the surface of the adhesive layer 2, and the wiring board is sandwiched between stainless steel plates. , 20 kgf / cm ² , and hot-pressed for 20 minutes while heating at 65 ° C. in a heating furnace. With this heating press, the surface of the adhesive layer 2 was flattened to form an interlayer resin insulating layer (see FIG. 14).

(15) By repeating the above steps (5) to (13), a conductor circuit was further provided, and a roughened layer 11 made of copper-nickel-phosphorus was provided on the surface of the conductor circuit.
However, no tin-substituted plating layer was formed on the surface of the roughened layer 11 (see FIGS. 15 to 19).

(16) 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 parts by weight of a dispersant antifoaming agent (manufactured by San Nopco, trade name: S-65), and 2 parts by weight of benzophenone (Kanto Chemical) as a photoinitiator with respect to these mixtures Parts, 0.2 parts by weight of Michler's ketone (manufactured by Kanto Chemical Co., Ltd.) as a photosensitizer, and add
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.

(17) The solder resist composition was applied to both sides of the substrate obtained in (15) in a thickness of 20 μm. Next, after performing a drying process at 70 ° C. for 20 minutes and at 70 ° C. for 30 minutes, a 5 mm-thick soda lime glass substrate on which a circular pattern (mask pattern) of a solder resist opening is drawn by a chromium layer is placed on a chrome layer. The side on which the layer was formed was placed in close contact with the solder resist layer, exposed to ultraviolet light of 1000 mJ / cm ² , and subjected to DMTG development treatment. Then, at 80 ° C for 1 hour, at 100 ° C for 1 hour, at 120 ° C for 1 hour, and at 150 ° C for 3 hours.
Heat treatment under the condition of time, opening the upper surface of the solder pad, the via hole and its land (opening diameter 200μm)
A pattern (thickness: 20 μm) of the solder resist layer was formed.

(19) Next, the substrate on which the solder resist layer 14 has been formed is washed with a pH of 30 g / l of nickel chloride, 10 g / l of sodium hypophosphite, and 10 g / l of sodium citrate.
= 5 for 20 minutes to form a nickel plating layer 15 having a thickness of 5 μm at the opening. Further, the substrate was placed on an electroless gold plating solution comprising 2 g / l of potassium gold cyanide, 75 g / l of ammonium chloride, 50 g / l of sodium citrate, and 10 g / l of sodium hypophosphite at 93 ° C. for 23 seconds. By dipping, a gold plating layer 16 having a thickness of 0.03 μm was formed on the nickel plating layer 15.

(20) Then, a solder paste is printed on the opening of the solder resist layer 14 and reflowed at 200 ° C. to form a solder bump (solder body) 17 to manufacture a printed wiring board having the solder bump. (See FIG. 20).

(Example 2) Semi-additive method 0.92μ
m A printed wiring board having solder bumps was manufactured in the same manner as in Example 1 except that the adhesive solution for electroless plating shown below was used. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, caprolactone-modified tris (acroxyethyl) isocyanurate (trade name, manufactured by Toagosei Co., Ltd., trade name: Aronix M315) which is a photosensitive monomer ) 4
Parts by weight, 2 parts by weight of a photoinitiator (manufactured by Ciba Geigy, trade name: Irgacure 907), 0.2 parts by weight of a photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), and further, epoxy resin particles (Sanyo Chemical Co., Ltd.) The particle size distribution of the particles is shown in Fig. 26. The average particle size of the particles is 0.92 µm in median diameter, and the standard deviation is 0.275. It is distributed in the range of 1.98 μm, and the particle size at the peak of the particle size distribution is 1.00 μm
Then, as is clear from FIG. 26, the number of peaks is one. The particle size distribution was measured using a Shimadzu laser diffraction particle size distribution analyzer: SALD-2000, manufactured by Shimadzu Corporation. )
After mixing 25 parts by weight, 30.0 parts by weight of NMP (normal methylpyrrolidone) were added and mixed, adjusted to a viscosity of 7 Pa · s with a homodisper stirrer, and then kneaded with three rolls to obtain a photosensitive composition. An adhesive solution for electroless plating (interlayer resin insulating agent) was used.

Example 3 Fully Additive Method (1) A 25% acrylate of a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., molecular weight: 2500) dissolved in DMDG (diethylene glycol dimethyl ether) was used in parts by weight, and polyether sulfone (PES) was used. ) 12 parts by weight, 2 parts by weight of imidazole curing agent (manufactured by Shikoku Chemicals, trade name: 2E4MZ-CN), caprolactone-modified tris (acroxyethyl) isocyanurate (manufactured by Toa Gosei, a photosensitive monomer)
Trade name: Aronix M315) 4 parts by weight, photoinitiator (Ciba Geigy, trade name: Irgacure 907) 2 parts by weight, photosensitizer (Nippon Kayaku, trade name: DETX-S) 0.2 parts by weight, In addition, epoxy resin particles (manufactured by Sanyo Chemicals, trade name: Polymer Pole S-031)
See Figure 25. The average particle size of these particles is 0.51μ in median diameter.
m, with a standard deviation of 0.193. This particle is 0.09μ
The particle size is 0.58 μm at the peak of the particle size distribution, and as shown in FIG. 25, there is one peak. The particle size distribution was measured using a Shimadzu laser diffraction particle size distribution analyzer: SALD-2000, manufactured by Shimadzu Corporation. ) After mixing 25 parts by weight,
Mix while adding 30.0 parts by weight of NMP (normal methylpyrrolidone) and use a homodisper stirrer to obtain a viscosity of 7 Pa · s.
Then, the mixture was kneaded with three rolls to obtain a photosensitive electroless plating adhesive solution (interlayer resin insulating agent).

(2) The adhesive solution for electroless plating obtained in (1) was applied to both sides of the core substrate obtained according to (1) and (2) of Example 1 by a roll coater, and After standing for 20 minutes, drying was performed at 60 ° C. for 30 minutes to form an adhesive layer 2 having a thickness of 60 μm.

(3) A polyethylene terephthalate film (translucent film) was adhered to the adhesive layer 2 formed on both sides of the substrate in the above (2) via an adhesive. And
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 with a light-shielding ink having a thickness of 5 μm is placed with the side on which the circular pattern is drawn in close contact with the adhesive layer 2. Then, exposure was performed by irradiating ultraviolet rays.

(4) The exposed substrate is spray-developed with a DMTG (triethylene glycol dimethyl ether) solution to form a 100 μm via hole in the adhesive layer 2.
An opening of mφ was formed. 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 a heat treatment at 150 ° C. for 5 hours, an adhesive layer 2 having a thickness of 50 μm having openings (openings for forming via holes) 6 having excellent dimensional accuracy corresponding to a photomask film.
Was formed. Note that the roughened layer 11 was partially exposed in the opening 6 serving as a via hole (see FIG. 7).

(5) The substrate on which the via hole forming openings 6 are formed is immersed in chromic acid for 2 minutes to dissolve and remove the epoxy resin particles present on the surface of the adhesive layer 2. The surface was roughened and then immersed in a neutralizing solution (manufactured by Shipley) and then washed with water (see FIG. 8).

(6) On the other hand, a cresol novolak type epoxy resin dissolved in DMDG (trade name: EO, manufactured by Nippon Kayaku)
46.7 parts by weight of a photosensitizing oligomer (molecular weight 4000) obtained by acrylizing 50% of epoxy groups of CN-103S), and 80 parts by weight of a bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name: Epicoat) dissolved in methyl ethyl ketone 1001)
15.0 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, trade name: 2E4MZ-CN) 1.6 parts by weight, photosensitive monomer polyvalent acrylate (Nippon Kayaku, R-604) 3 parts by weight, also polyvalent acrylic monomer (Kyoeisha Chemical, product name: DPE-
6A) 1.5 parts by weight were mixed, and 0.5 part by weight of an acrylate polymer (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Polyflow 75) was mixed with the total weight of the mixture and stirred. Prepared. Also, 2 parts by weight of benzophenone as a photoinitiator (manufactured by Kanto Kagaku) and 0.2 parts by weight of Michler's ketone as a photosensitizer (manufactured by Kanto Kagaku) are dissolved in 3 parts by weight of DMDG heated to 40 ° C. B was prepared. Then, the liquid mixture A and the liquid mixture B were mixed to obtain a liquid resist.

(7) The liquid resist is applied using a roll coater on the substrate after the treatment of the above (5),
For 30 minutes to form a resist layer having a thickness of 30 μm. Then, L / S (ratio of line to space) = 50
A mask film on which a / 50 conductor circuit pattern is drawn is brought into close contact with the mask film, and exposed to 1000 mJ / cm ² using an ultra-high pressure mercury lamp.
By performing a DMDG spray development process, a plating resist with the conductor circuit pattern portion removed was formed on the substrate, and further exposed at 6000 mJ / cm ² with an ultra-high pressure mercury lamp.
Heat treatment was performed at 100 ° C. for 1 hour and then at 150 ° C. for 3 hours to form a permanent resist 3 on the adhesive layer (interlayer resin insulating layer) 2 (see FIG. 21).

(8) The substrate on which the permanent resist 3 is formed is
After immersion treatment in a sulfuric acid aqueous solution of 00 g / l to activate the catalyst nuclei, primary plating is performed using an electroless copper-nickel alloy plating bath having the following composition, and a resist non-formed portion having a thickness of about 1.7 μm is formed. A copper-nickel-phosphorus plating thin film was formed. At this time, the temperature of the plating bath was 60 ° C., and the plating immersion time was 1 hour. The deposition rate was 1.7 μm / hour.

(9) The substrate that has been subjected to the primary plating is pulled out of the plating bath, the plating solution adhering to the surface is washed away with water, and the substrate is treated with an acidic solution, whereby copper-nickel-phosphorus plating is performed. The oxide film on the surface of the thin film was removed. Then, without performing Pd substitution, the outer conductor pattern and vias required as conductors by the additive method are subjected to secondary plating on the copper-nickel-phosphorous plating thin film using an electroless copper plating bath having the following composition. A hole (BVH) was formed (see FIG. 22). At this time, the temperature of the plating bath is 50 to 70 ° C., and the plating immersion time is 90 to 36.
0 minutes. Metal salts _{... CuSO 4 · 5H 2 O:} 8.6 mM Complexing agent ... TEA: 0.15 M reducing agent ... HCHO: 0.02 M Others ... stabilizer (bipyridyl, potassium ferrocyanide and the like): a small amount deposition rate, 6 [mu] m / Time

(10) After the conductive layer is formed by the additive method in this manner, one side of the substrate is subjected to belt sander polishing using # 600 belt polishing paper to make contact with the upper surface of the permanent resist, the upper surface of the conductive circuit, and the via hole. Was polished until it was flush with the upper surface of the land. Subsequently, buffing was performed to remove the scratches caused by the belt sander (only buffing may be performed). Then, the other surface was similarly polished to obtain a printed wiring board having both surfaces smooth.

(11) Then, the printed wiring board whose surface was smoothed was replaced with copper sulfate 8 g / l, nickel sulfate 0.6 g / l,
PH = 9 consisting of 15 g / l citric acid, 29 g / l sodium hypophosphite, 31 g / l boric acid, 0.1 g / l surfactant
Of the copper-nickel-phosphorus alloy having a thickness of 3 μm was formed on the conductor surface exposed on the substrate surface (see FIG. 23). Thereafter, the above-described steps were repeated to form still more conductive layers by the additive method, and the wiring layers were built up in this manner to obtain a six-layered multilayer printed wiring board.

(12) Further, a solder resist layer 14 and solder bumps 17 were formed according to the steps (16) to (20) of Example 1, and a printed wiring board having the solder bumps 17 was manufactured (see FIG. 24). .

Comparative Example 1 Semi-additive method (3.9 μm)
m / 0.5 μm) A printed wiring board having solder bumps was manufactured in the same manner as in Example 1 except that the adhesive solution for electroless plating shown below was used. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, caprolactone-modified tris (acroxyethyl) isocyanurate (trade name, manufactured by Toagosei Co., Ltd., trade name: Aronix M315) which is a photosensitive monomer ) 4
Parts by weight, 2 parts by weight of a photoinitiator (trade name: Irgacure 907, manufactured by Ciba Geigy), 0.2 parts by weight of a photosensitizer (trade name: DETX-S, manufactured by Nippon Kayaku), and further, epoxy resin particles (
After mixing 10 parts by weight of an average particle size of 3.9 μm and 25 parts by weight of an average particle size of 0.5 μm (trade name: Toray Pearl, manufactured by Toray), 30.0 parts by weight of NMP (normal methylpyrrolidone) was added. Mix, adjust the viscosity to 7 Pa · s with a homodisper stirrer, and then knead with 3 rolls to obtain a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent).
Was used.

(Comparative Example 2) Semi-additive method (pulverized powder of 1.6 μm + epoxy / PES matrix) (1) JP-A-61-276875 (USP 4752499, US
Epoxy resin particles were prepared according to the method described in JP-A-5921472.
That is, an epoxy resin (trade name: T, manufactured by Mitsui Petrochemical Industries, Ltd.)
A-1800) is dried in a hot air dryer at 180 ° C. for 4 hours and cured. The cured epoxy resin is roughly pulverized, and then frozen with liquid nitrogen while using an ultrasonic jet pulverizer (Nippon Pneumatic). Industrial product, trade name: Accu Cut B
-18 type) to prepare epoxy resin particles having an average particle size of 1.6 μm.

(2) The manufacture of a printed wiring board was the same as that of Example 1 except that the following adhesive solution for electroless plating was used. That is, 34 parts by weight of 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether), polyether sulfone (PE
S) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight of caprolactone-modified tris (acroxyethyl) isocyanurate (manufactured by Toa Gosei, trade name: Aronix M315) ), 4 parts by weight, 2 parts by weight of a photoinitiator (trade name: Irgacure 907, manufactured by Ciba Geigy), 0.2 parts by weight of a photosensitizer (trade name: DETX-S, manufactured by Nippon Kayaku), and (1) 35 parts by weight of an epoxy resin particle having an average particle size of 1.6 μm were mixed with 30.0 parts by weight of NMP (normal methylpyrrolidone), and the mixture was mixed with a homodisper stirrer.
The pressure was adjusted to Pa · s, and then a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent) obtained by kneading with three rolls was used.

(Comparative Example 3) Semi-additive method (1.6 μm particles + epoxy / PES matrix) A print having solder bumps in the same manner as in Example 1 except that the adhesive solution for electroless plating shown below was used. A wiring board was manufactured. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, caprolactone-modified tris (acroxyethyl) isocyanurate (trade name, manufactured by Toagosei Co., Ltd., trade name: Aronix M315) which is a photosensitive monomer ) 4
Parts by weight, 2 parts by weight of a photoinitiator (manufactured by Ciba-Geigy, trade name: Irgacure 907), 0.2 parts by weight of a photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), and further, epoxy resin particles (manufactured by Toray) (Trade name: Trepearl) having an average particle diameter of 1.6 μm was mixed with 35 parts by weight, and then mixed while adding 30.0 parts by weight of NMP (normal methylpyrrolidone), and the mixture was adjusted to a viscosity of 7 Pa · s with a homodisper stirrer. Then, a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent) obtained by kneading with three rolls was used.

(Comparative Example 4) Full additive method (3.9 μm)
m / 0.5 μm) A printed wiring board having solder bumps was manufactured in the same manner as in Example 3, except that the adhesive solution for electroless plating shown below was used. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, caprolactone-modified tris (acroxyethyl) isocyanurate (trade name, manufactured by Toagosei Co., Ltd., trade name: Aronix M315) which is a photosensitive monomer ) 4
Parts by weight, 2 parts by weight of a photoinitiator (manufactured by Ciba-Geigy, trade name: Irgacure 907), 0.2 parts by weight of a photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), and further, epoxy resin particles (manufactured by Toray) After mixing 10 parts by weight of a product having a mean particle size of 3.9 μm and 25 parts by weight of a product having a mean particle size of 0.5 μm, NMP (normal methylpyrrolidone) 30.0%
The mixture was mixed while adding parts by weight, and the viscosity was adjusted to 7 Pa · s with a homodisper stirrer. Subsequently, a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent) obtained by kneading with three rolls was used. Was.

(Comparative Example 5) Full additive method (1.6 μm ground powder + epoxy / PES matrix) (1) Epoxy resin particles were prepared according to JP-A-61-276875. That is, the epoxy resin (trade name: TA-1800, manufactured by Mitsui Petrochemical Co., Ltd.) is dried and cured at 180 ° C. for 4 hours in a hot air dryer, and the cured epoxy resin is roughly pulverized and then liquid While freezing with nitrogen, the particles were classified using an ultrasonic jet pulverizer (trade name: Acucut B-18, manufactured by Nippon Pneumatic Industries Ltd.), and the average particle size was 1.6.
μm epoxy resin particles were prepared.

(2) The manufacture of the printed wiring board was the same as that of Example 3 except that the following adhesive solution for electroless plating was used. That is, 34 parts by weight of 25% acrylate of cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether), polyether sulfone (PE
S) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight of caprolactone-modified tris (acroxyethyl) isocyanurate (manufactured by Toa Gosei, trade name: Aronix M315) ), 4 parts by weight, 2 parts by weight of a photoinitiator (trade name: Irgacure 907, manufactured by Ciba Geigy), 0.2 parts by weight of a photosensitizer (trade name: DETX-S, manufactured by Nippon Kayaku), and (1) 35 parts by weight of an epoxy resin particle having an average particle size of 1.6 μm were mixed with 30.0 parts by weight of NMP (normal methylpyrrolidone), and the mixture was mixed with a homodisper stirrer.
The pressure was adjusted to Pa · s, then kneaded with three rolls, and a photosensitive adhesive solution for electroless plating (interlayer resin insulating agent) was used.

(Comparative Example 6) Full additive method (1.6 μm particles + epoxy / PES matrix) A print having solder bumps in the same manner as in Example 3 except that the adhesive solution for electroless plating shown below was used. A wiring board was manufactured. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight of caprolactone modified tris (acroxyethyl) isocyanurate (trade name: Alonix M315) ) 4
Parts by weight, 2 parts by weight of a photoinitiator (manufactured by Ciba-Geigy, trade name: Irgacure 907), 0.2 parts by weight of a photosensitizer (manufactured by Nippon Kayaku, trade name: DETX-S), and further, epoxy resin particles (manufactured by Toray) Trepearl) with an average particle size of 1.6 μm
After mixing, 30.0 parts by weight of NMP (normal methylpyrrolidone) were added and mixed, the viscosity was adjusted to 7 Pa · s with a homodisper stirrer, and then the mixture was kneaded with three rolls. An adhesive solution for electrolytic plating (interlayer resin insulating agent) was used.

Comparative Example 7 Semi-additive method 5.5 μm / 0.5 μm (JP-A-7-34048, US Pat. No. 5,519,177)
A printed wiring board having solder bumps was manufactured in the same manner as in Example 1, except that the adhesive solution for electroless plating shown below was used. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, photosensitive monomer trimethyltriacrylate (TMPTA) 5 parts by weight, photoinitiator (manufactured by Ciba-Geigy), trade name : Irgacure 907) 2
After mixing 10 parts by weight of epoxy resin particles (trade name: Toray Pearl, manufactured by Toray) with an average particle size of 5.5 μm and 5 parts by weight of an epoxy resin particle with an average particle size of 0.5 μm, NMP
(Normal methylpyrrolidone) was mixed while adding 30.0 parts by weight, the viscosity was adjusted to 7 Pa · s with a homodisper stirrer, and then kneaded with three rolls to obtain a photosensitive adhesive solution for electroless plating (interlayer). (Resin insulating agent).

Comparative Example 8 Fully Additive Method 5.5 μm / 0.5 μm (JP-A-7-34048, US Pat. No. 5,519,177)
A printed wiring board having solder bumps was manufactured in the same manner as in Example 2 except that the adhesive solution for electroless plating shown below was used. That is, 25% of the cresol novolak type epoxy resin (manufactured by Nippon Kayaku, molecular weight 2500) dissolved in DMDG (diethylene glycol dimethyl ether).
34 parts by weight of acrylate, polyether sulfone (P
ES) 12 parts by weight, imidazole curing agent (manufactured by Shikoku Chemicals, 2E4MZ-CN), 2 parts by weight, photosensitive monomer trimethyltriacrylate (TMPTA) 5 parts by weight, photoinitiator (manufactured by Ciba-Geigy), trade name : Irgacure 907) 2
After mixing 10 parts by weight of epoxy resin particles (trade name: Toray Pearl, manufactured by Toray) with an average particle size of 5.5 μm and 5 parts by weight of an epoxy resin particle with an average particle size of 0.5 μm, NMP
(Normal methylpyrrolidone) was mixed while adding 30.0 parts by weight, the viscosity was adjusted to 7 Pa · s with a homodisper stirrer, and then kneaded with three rolls to obtain a photosensitive adhesive solution for electroless plating (interlayer). (Resin insulating agent).

The printed wiring boards according to the examples and the comparative examples thus manufactured were subjected to the following tests and evaluations. . The peel strength of the wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8 was measured in accordance with JIS-C-6481. . With respect to the wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8, the wiring boards were cross-cut, and the depths of the depressions on the roughened surface were measured by observing the cross section with a metallographic microscope. . The surface resistance values of the wiring boards of Examples 1 and 2 and Comparative Examples 1 to 3 and 7 were measured. . The wiring boards of Example 3 and Comparative Examples 4 to 6, and 8 were left for 48 hours under the conditions of a humidity of 85%, a temperature of 130 ° C., and a voltage of 3.3 V, and the surface resistance was measured. . The wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8 were subjected to 500 heat cycle tests at −55 ° C. to 125 ° C. to check for cracks. . With respect to the wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8, the formation limit of L / S was examined. . Heating tests were performed on the wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8. The conditions for this test are 128 ° C
48 hours. According to this heating test, if there is a resin residue in the opening for forming the via hole, the via hole is peeled off. The presence or absence of such peeling was measured by the conduction resistance of the via hole, and it was determined that the via hole was peeled when the conduction resistance increased. . For each of the wiring boards of Examples 1 to 3 and Comparative Examples 1 to 8, 100 wiring boards were prepared, and the occurrence ratio of interlayer dielectric breakdown was measured.

Table 1 shows the results of these tests and evaluations.

[Table 1]

[0105] As is clear from the results shown in this table, when the adhesive for electroless plating of the present invention is used, even if the depth of the depression on the roughened surface is smaller than the conventional one (3 μm), the practical peel strength is 1.0. kg / cm can be achieved. As a result, the printed wiring board of the present invention has a L / L
S can be further reduced. . The heat-resistant resin particles used in the adhesive for electroless plating and the printed wiring board according to the present invention have an average particle size of 1.5 μm or less, and have a maximum particle size of 2 μm as understood from the particle size distribution. Therefore, no void is generated between the layers by the roughening treatment, and there is no destruction of the interlayer insulation due to conduction between the upper layer and the lower layer. . Further, when an opening for forming a via hole is provided in the interlayer resin insulating layer of the substrate whose surface of the lower conductive circuit is roughened, the resin remains on the roughened surface. in this regard,
Comparing Examples 1 and 2 with Comparative Examples 2 and 3, the presence of fine particles of 1 μm or less makes it possible to remove such resin residue during the roughening treatment, and does not cause peeling of the via hole even in the heating test. It is estimated to be. . The wiring boards of Examples 1 and 2 have higher surface resistance values than Comparative Examples 1 and 7. This is presumably because in the wiring board of Comparative Example 1, the depression on the roughened surface was too deep, and the electroless plating film could not be dissolved and removed and remained. . The surface resistance of the wiring board of Example 3 did not decrease even when exposed to high temperature and high humidity conditions. On the other hand, when the wiring boards of Comparative Examples 4 and 8 are exposed to a high-temperature and high-humidity condition, the surface resistance decreases. This is presumed to be that the wiring boards of Comparative Examples 4 and 8 had a larger amount of catalyst nuclei Pd adhered to the wiring boards of Comparative Examples 4 and 8 than those of Example 3 due to the deep depressions on the roughened surface, and this was the cause of the decrease in surface resistance. are doing. . No cracks occurred in the wiring boards of Examples 1 and 2 and Comparative Examples 1 and 7 due to the heat cycle. In contrast, in the wiring boards of Example 3 and Comparative Examples 4, 5, 6, and 8, cracks occurred in the interlayer resin insulating layer (adhesive layer for electroless plating) starting from the interface between the plating resist and the conductive circuit. . . In the wiring boards of Comparative Examples 2 and 5, a crack originating from the anchor dent below the conductor circuit occurred in the adhesive layer for electroless plating. This is thought to be because, in the case of the crushed powder, since the shape is angular, the formed anchor dent is also angular, so that stress concentration occurs during a heat cycle and cracks are generated. That is, when such a crushed powder is used, the peel strength is improved, but cracks occur during a heat cycle.

In the examples of JP-A-61-276875, since an epoxy-modified polyimide resin is used as the resin matrix, the toughness is higher than that of the epoxy-PES resin, and a peel strength of 1.6 kg / cm is obtained. It is thought that it was done.

[0107]

As described above, according to the adhesive for electroless plating of the present invention, a practical peel strength can be secured.
It is possible to provide a printed wiring board which has a high surface resistance, can form a fine pattern up to L / S = 20/20 μm, and has no interlayer dielectric breakdown due to a roughening treatment. Furthermore, according to the adhesive for electroless plating of the present invention, the adhesive resin remaining at the bottom of the via hole opening can be removed at the time of the roughening treatment, so that a printed wiring board using such an adhesive can be used in a heating test. No via-hole peeling.

[Brief description of the drawings]

FIG. 1 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using an adhesive for electroless plating according to the present invention.

FIG. 2 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using an adhesive for electroless plating according to the present invention.

FIG. 3 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 4 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 5 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 6 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 7 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 8 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 9 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 10 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 11 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 12 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 13 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 14 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 15 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 16 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 17 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 18 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 19 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 20 is a view showing one step in the production of a multilayer printed wiring board by a semi-additive method using the adhesive for electroless plating according to the present invention.

FIG. 21 is a view showing one step in the production of a multilayer printed wiring board by a full additive method using the adhesive for electroless plating according to the present invention.

FIG. 22 is a diagram showing one step in the production of a multilayer printed wiring board by a full additive method using the adhesive for electroless plating according to the present invention.

FIG. 23 is a view showing one step in manufacturing a multilayer printed wiring board by a full additive method using the adhesive for electroless plating according to the present invention.

FIG. 24 is a view showing one step in the production of a multilayer printed wiring board by a full additive method using the adhesive for electroless plating according to the present invention.

FIG. 25 is a particle size distribution showing the relationship between the particle size of the heat-resistant resin particles according to the present invention and the abundance ratio (abundance) of the heat-resistant resin particles at the particle size.

FIG. 26 is a particle size distribution showing the relationship between the particle diameter of the heat-resistant resin particles according to the present invention and the abundance ratio (amount) of the heat-resistant resin particles at the particle diameter.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 interlayer resin insulating layer (adhesive layer for electroless plating) 3 permanent resist (plating resist) 4 inner layer conductor circuit (inner layer pattern) 5 inner layer conductor circuit (second layer pattern) 6 opening for via hole 7 via hole 8 Copper foil 9 Through hole 10 Resin filler 11 Roughening layer 12 Electroless plating film 13 Electrolytic plating film 14 Solder resist layer 15 Nickel plating layer 16 Gold plating layer 17 Solder body (solder bump)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H05K 3/46 H05K 3/46 T (58) Investigated field (Int.Cl. ⁷ , DB name) H05K 3/38 H05K 3 / 18 H05K 3/46

Claims (10)

(57) [Claims] 1. An electroless plating method comprising dispersing hardened heat-resistant resin particles soluble in an acid or an oxidizing agent in an uncured heat-resistant resin matrix which becomes hardly soluble in an acid or an oxidizing agent by a hardening treatment. In the adhesive, the heat-resistant resin particles have a distribution such that the average particle size is 1.5 μm or less, the maximum particle size is less than 2 μm, and the particle size showing a particle size distribution peak is in a region of 1.5 μm or less. An adhesive for electroless plating characterized by having. 2. The heat-resistant resin particles have an average particle size.
The adhesive for electroless plating according to claim 1, wherein the adhesive has a thickness of 0.1 to 1.0 µm. 3. The adhesive for electroless plating according to claim 1, wherein the heat-resistant resin particles are spherical particles. 4. The adhesive for electroless plating according to claim 1, wherein the heat-resistant resin particles have a single particle size distribution peak. 5. A printed wiring comprising a substrate, a surface-roughened cured electroless plating adhesive layer, and a conductor circuit formed on the roughened surface of the adhesive layer surface. In the plate, the adhesive layer is obtained by dispersing cured heat-resistant resin particles soluble in an acid or an oxidizing agent in an uncured heat-resistant resin matrix that becomes hardly soluble in an acid or an oxidizing agent by a curing treatment. It is made of an adhesive for electroless plating, and the roughened surface of this layer is roughened so that the depth Rmax of the depression becomes 1 to 5 μm, and the heat-resistant resin particles of the adhesive are
A printed wiring board having an average particle size of 1.5 μm or less, a maximum particle size of less than 2 μm, and a distribution in which the particle size showing a particle size distribution peak falls in a region of 1.5 μm or less. . 6. The heat-resistant resin particles have an average particle size.
The printed wiring board according to claim 5, wherein the thickness is 0.1 to 1.0 m. 7. The printed wiring board according to claim 5, wherein the heat-resistant resin particles are spherical particles. 8. The printed wiring board according to claim 5, wherein the heat-resistant resin particles have a single particle size distribution peak. 9. The conductive circuit formed on a roughened surface of the adhesive layer surface is constituted by an electroless plating film and an electrolytic plating film. The printed wiring board according to the item. 10. The conductor circuit formed on the roughened surface of the adhesive layer surface, wherein a roughened layer is formed on at least a part of the surface. 1
The printed wiring board according to the item.