JP2002217547A - Manufacturing method of resin film, and multilayer printed wiring substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin film, used in manufacturing of a multilayer printed wiring substrate, which can satisfy the properties of shape keeping properties when being stuck on a substrate wherein a conductor circuit is formed and can ensure characteristics required by a formed interlayer resin insulation layer as well, and furthermore, enables a roughened surface with desired irregularities to be formed in a surface thereof. SOLUTION: The resin film is used for manufacturing of a multilayer printed wiring substrate, wherein a conductor circuit and an interlayer resin insulation layer are successively laminated and formed on a substrate. In the resin film, particles which are soluble in acid or oxidizer, are dispersed in resin, which is hardly soluble in acid or oxidizer. The hardly soluble resin is a resin composite consisting of two kinds of thermosetting resins and at least one kind of thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin film used for manufacturing a multilayer printed wiring board and a method for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art As the frequency of a signal becomes higher, the material of a package substrate is required to have a low dielectric constant and a low dielectric loss tangent. Therefore, the mainstream of the package substrate material is shifting from ceramic to resin.

A multilayer printed wiring board called a so-called multilayer build-up wiring board is manufactured by a semi-additive method or the like, and has a thickness of 0.5 to 1.5 mm called a core.
It is manufactured by alternately laminating conductive circuits made of copper or the like and interlayer resin insulating layers on a resin substrate reinforced with a glass cloth or the like. The connection between the conductor circuits via the interlayer resin insulation layer of the multilayer printed wiring board is performed by via holes or the like.

Conventionally, build-up multilayer printed wiring boards have been manufactured by a method disclosed in, for example, Japanese Patent Application Laid-Open No. 4-55555. That is, first, a through-hole is formed in a copper-clad laminate on which a copper foil is stuck, and then a through-hole is formed by performing an electroless copper plating process. Subsequently, the surface of the substrate is etched into a conductor pattern to form a conductor circuit, and on the surface of the conductor circuit,
A roughened surface is formed by electroless plating or etching.
Then, after a resin insulating layer containing epoxy acrylate or the like is formed on the conductor circuit having the roughened surface, exposure and development are performed to form a via hole opening.
After V curing and main curing, an interlayer resin insulating layer is formed.

Further, after roughening the interlayer resin insulating layer with an acid or an oxidizing agent, a thin electroless plating film is formed, and a plating resist is formed on the electroless plating film.
Thickening is performed by electrolytic plating, and etching is performed after the plating resist is stripped to form a conductive circuit connected to the lower conductive circuit and the via hole. After repeating this process, finally, a solder resist layer for protecting the conductor circuit is formed, an opening is formed for connection with an IC chip or the like, plating is performed on the exposed conductor circuit, and a solder paste is applied. By printing and forming solder bumps,
Complete the manufacture of the build-up multilayer printed wiring board.

[0006] The build-up multilayer printed wiring board manufactured in this manner is connected to another board called a motherboard or a daughter board.
An electronic component such as a capacitor is mounted, and wiring is formed to match electrical characteristics such as characteristic impedance, and then used as a package substrate.

In such a method for manufacturing a multilayer printed wiring board, an interlayer resin insulating layer made of a resin composition containing a photosensitive resin is formed on a substrate on which a conductive circuit is formed, and then the via is formed by exposure and development. A hole opening was formed. More specifically, Japanese Patent Application Laid-Open No. H07-197007 discloses a resin composite made of a thermosetting resin and a thermoplastic resin and having photosensitivity.
An interlayer resin insulating layer has been formed using a resin composition disclosed in 33991, JP-A-7-102175, and the like.

In recent years, with the increase in density and functionality of multilayer printed wiring boards, L / S (Line / Space: width of conductor circuit / distance between conductor circuits) of conductor circuits has been reduced.
It is necessary to reduce the diameter of the via hole opening. However, using the resin composition as described above,
In the method of forming a via hole opening for performing exposure and development processing, it was difficult to form a via hole opening having a small diameter and a desired shape. Also, in the case of forming a via hole opening by exposure and development processing, it is necessary to give consideration to the environment for processing and reuse of the developing solution used in this processing, which imposes an economic burden. Had become.

On the other hand, it is generally said that the use of a laser makes it possible to form an opening having a smaller diameter than in the case of using an exposure and development process.
Therefore, a method of forming a via hole opening or the like by laser processing using the resin composition disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-33991 was examined. However, due to the flatness of the formed layer and the like, It has been difficult to form a via hole opening having a small diameter and a desired shape by laser processing.

On the other hand, in Japanese Patent Application Laid-Open Nos. 11-1547 and 11-87927, a resin film is adhered by pressure bonding under reduced pressure or vacuum, and a via hole opening or the like is formed by laser processing. A method for manufacturing a multilayer printed wiring board in which a roughened surface is provided on the surface of an insulating layer made of a resin film, and a metal layer is further provided to form a conductor circuit and a via hole. .

[0011] A resin film comprising an epoxy resin composition containing an epoxy resin, a phenolic resin composition, a rubber component and a curing accelerator disclosed in Japanese Patent Application Laid-Open No. 11-1547 is formed on a substrate on which a conductive circuit is formed. When the interlayer resin insulation layer is formed by bonding, the upper surface of the bonded resin film may not be flat due to the shape of the roughened surface formed on the surface of the conductive circuit, or the upper surface of the conductive circuit may not be in contact with the conductive circuit. Due to the height difference from the formed portion, the resin film may not be completely filled in the non-conductive circuit formed portion, or irregularities (undulations) may occur on the upper surface of the adhered resin film. That is, this resin film did not have sufficient shape retention during pressure bonding, and it was difficult to form a resin film layer (interlayer resin insulation layer) having a uniform thickness. Therefore, when a via hole opening or the like is formed in such a resin film layer by laser processing, an opening having a uniform shape cannot be formed, and a multilayer printed wiring board manufactured using a resin film cannot be formed. There is a problem that it leads to a decrease in connectivity and reliability. In order to solve such a problem, a method of dispersing the additive in the resin film was also examined.However, in terms of the dispersibility of the additive, the interaction with the soluble particles, and the like, it was sufficient to solve the above problem. Could not be obtained.

[0012]

On the other hand, Japanese Patent Application Laid-Open No. 11-8 / 1999
The resin film disclosed in Japanese Patent No. 7927 includes a liquid epoxy resin at room temperature, a binder polymer (for example, a thermoplastic resin) for improving mechanical strength and flexibility, and a curing agent. It was a resin film. When a resin film containing one kind of thermosetting resin and one kind of thermoplastic resin is attached to a substrate on which a conductive circuit is formed, the resin film has a roughened surface formed on the surface of the conductive circuit. Because it can follow, the upper surface of the formed resin film layer is flat, and even when the conductive circuit non-formed portion is completely filled, a binder polymer such as a thermoplastic resin is blended. Therefore, no irregularities (undulations) were generated on the upper surface of the resin film layer. Therefore, such a resin film has a small diameter due to the laser treatment,
It was suitable for forming a via hole opening having a desired shape.

However, when an interlayer resin insulation layer is formed by curing this resin film layer, the properties (heat resistance, adhesion to a conductor circuit, crack resistance, etc.) required of the cured interlayer resin insulation layer are obtained. ) Could not be fully satisfied. This is because the composition of the resin film is
It was selected to ensure characteristics such as followability and shape retention to roughened surfaces and via holes before curing, and was selected as a result of deep consideration of the characteristics of the interlayer resin insulation layer after curing. This is because it was not a composition. In other words, in order to satisfy the conformability to shape and conformity to irregularities required before curing, a thermosetting resin that is relatively low in molecular weight and easily conforms to irregularities, etc. It is necessary to blend a thermoplastic resin having a certain range, and when a composition that satisfies the above characteristics is formed using one kind of thermosetting resin and one kind of thermoplastic resin, It has been difficult to completely satisfy the properties required for the cured interlayer resin insulation layer.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a resin film used for manufacturing a multilayer printed wiring board, wherein the resin film is formed on a substrate on which a conductive circuit is formed. It not only satisfies the conformability and the shape retention at the time of bonding, but also has excellent properties required for the interlayer resin insulating layer formed by curing, and further has a roughened surface having desired irregularities on its surface. It is to provide a resin film capable of forming a surface. Another object of the present invention is to provide a method for manufacturing a multilayer printed wiring board using the above resin film.

[0015]

Means for Solving the Problems Accordingly, the present inventors have:
In addition to satisfying the characteristics required for the resin film before curing (followability, shape retention, etc.), the composition of the resin film that satisfies the characteristics required for the interlayer resin insulation layer after curing has been eagerly studied. As a result of research, particles that are soluble in an acid or an oxidizing agent are dispersed in a resin that is hardly soluble in an acid or an oxidizing agent.
A resin film using a resin composite composed of a kind of thermosetting resin and a thermoplastic resin was found to be capable of satisfying the above-mentioned required characteristics, and reached an invention having the following content as a gist configuration. did.

That is, the resin film of the present invention is a resin film used for manufacturing a multilayer printed wiring board in which a conductive circuit and an interlayer resin insulating layer are sequentially formed on a substrate. Alternatively, particles that are soluble in an acid or an oxidizing agent are dispersed in a resin that is hardly soluble in an oxidizing agent, and the hardly-soluble resin includes two types of thermosetting resins and at least one type of thermoplastic resin. It is a resin composite.

In the resin film, one of the thermosetting resins is preferably an epoxy resin. The two types of thermosetting resins are preferably an epoxy resin and a phenol resin, or an epoxy resin and a polyimide resin. Further, the thermoplastic resin,
Desirably, it is at least one selected from the group consisting of phenoxy resin, polyether sulfone and polysulfone.

The soluble particles are desirably at least one selected from the group consisting of resin particles, inorganic particles and metal particles. The method for manufacturing a multilayer printed wiring board according to the present invention is a method for manufacturing a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially formed on a substrate. To
A non-through hole and / or a through hole is formed by using the resin film of the present invention and pressing the resin film under a reduced pressure or vacuum under a pressure of 0.2 to 1 MPa.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The resin film of the present invention is a resin film used for manufacturing a multilayer printed wiring board in which a conductive circuit and an interlayer resin insulating layer are sequentially laminated on a substrate. Wherein particles which are soluble in an acid or an oxidizing agent are dispersed in a resin which is hardly soluble in an acid or an oxidizing agent, and the hardly soluble resin comprises two types of thermosetting resins and at least one type of thermoplastic resin. Characterized in that it is a resin composite comprising

According to the resin film of the present invention, particles that are soluble in an acid or an oxidizing agent are dispersed in a resin that is hardly soluble in an acid or an oxidizing agent. Since a resin composite comprising a conductive resin and at least one type of thermoplastic resin is used, when the resin film is attached, the shape of the surface of the substrate on which the conductor circuit is formed, including the surface of the conductor circuit, Excellent in followability and shape retention. This is because the resin film before curing
Because the relatively soft thermosetting resin and the relatively hard thermoplastic resin coexist, the presence of the relatively soft thermosetting resin will result in excellent followability to the roughened surface, This is because the presence of a hard thermoplastic resin results in excellent shape retention.

Further, since the interlayer resin insulating layer formed by curing the resin film contains two kinds of thermosetting resins, different characteristics can be secured at the same time. In particular, it is possible to achieve a plurality of characteristics compatible with an interlayer resin insulating layer made of only a single type of resin (for example, only an epoxy resin). Specifically, for example, it is possible to achieve compatibility between mechanical characteristics and adhesion to a conductor circuit, and compatibility between mechanical characteristics and heat resistance. Further, in the resin film of the present invention, particles soluble in the acid or the oxidizing agent are dispersed in the resin that is hardly soluble in the acid or the oxidizing agent, and the surface of the formed interlayer resin insulating layer has desired irregularities. A roughened surface can be formed. In addition, the resin film is suitable for forming desired irregularities on the wall surface of the via hole opening after forming the via hole opening.

Conventionally, when a multilayer printed wiring board is manufactured using a resin film made of a resin composite of a thermosetting resin and a thermoplastic resin, one type of each of the thermosetting resin and the thermoplastic resin is blended. The cured resin film is used and cured, and a thermosetting resin and a thermoplastic resin are made compatible with each other to form an interlayer resin insulating layer. However, when a resin composition comprising the above resin composite is formed into a film, the thermoplastic resin is not uniformly present in the resin film, and may become coarse and dense, which may be caused by uneven distribution of the thermoplastic resin. Then, a brittle portion occurs in the formed interlayer resin insulating layer, and cracks and the like occur in the interlayer resin insulating layer when immersed in a roughening solution such as an acid or an oxidizing agent or a plating solution,
A short circuit may occur between conductor circuits sandwiching the interlayer resin insulation layer.

On the other hand, the resin film of the present invention
Since different types of thermosetting resins are included, by selecting a resin that has a high affinity with the thermoplastic resin as the first thermosetting resin, a composite resin in which these resins are uniformly mixed is considered. Formed and as a second thermosetting resin,
By selecting a resin having an excellent affinity for the first thermosetting resin, it is possible to obtain a resin in which the above composite resin is dispersed in a compatible state in the second thermosetting resin. Before the curable resin is cured, the thermoplastic resin aggregates,
Non-uniform dispersion can be prevented, and the above-described inconvenience caused by the uneven existence of the thermoplastic resin can be avoided.Also, aggregation or non-uniformity of particles soluble in an acid or an oxidizing agent can be prevented. Dispersion can also be prevented. Further, in the resin film of the present invention, when two types of thermosetting resins having different curing temperatures are selected as the thermosetting resin, at a certain temperature, only the first thermosetting resin is brought into a cured state, Can be brought into an uncured state, and all the thermosetting resins can be cured by increasing the temperature. In this case, due to the presence of the second thermosetting resin, stress at the time of curing caused by the presence of the first thermosetting resin or the thermoplastic resin can be reduced, and cracks or the like may occur in the interlayer resin insulating layer at the time of curing. Can be prevented from occurring. Further, by adjusting the profile of the curing temperature (curing temperature, step cure), it is possible to form an interlayer resin insulating layer in which the thermosetting resin and the thermoplastic resin are completely compatible. In addition, the compatibility in this case, the thermosetting resin and the thermoplastic resin,
It is not a state of being completely mixed and one kind of resin, but a state in which each is intricately entangled in the state of resin and is pseudo-compatible with each other. In some places, a spherical domain structure Or a co-continuous structure.

[0024] The resin film of the present invention comprises a resin which is hardly soluble in an acid or an oxidizing agent (hereinafter referred to as a hardly soluble resin) and a particle which is soluble in an acid or an oxidizing agent (hereinafter referred to as a soluble particle).
Are dispersed, and a resin composite composed of two types of thermosetting resins and thermoplastic resins is used as the hardly-soluble resin.

The terms "sparingly soluble" and "soluble" used in the present invention refer to those having a relatively high dissolution rate when immersed in a solution containing the same acid or oxidizing agent for the same time. And those having a relatively slow dissolution rate are referred to as "poorly soluble" for convenience.

Examples of the soluble particles include resin particles soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble resin particles”), inorganic particles soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble inorganic particles”), and acid or oxidizing agents. Metal particles soluble in the agent (hereinafter referred to as soluble metal particles).
These soluble particles may be used alone or in combination of two or more.

The shape of the soluble particles is not particularly limited.
Spherical, crushed and the like. The shape of the soluble particles is desirably a uniform shape. This is because a roughened surface having unevenness with a uniform roughness can be formed.

The average particle size of the above-mentioned soluble particles is 0.1.
1 to 10 μm is desirable. The soluble particles may be composed of only particles having the same particle diameter, or may contain two or more kinds of particles having different particle diameters within the above-mentioned particle diameter. For example, it contains soluble particles having an average particle size of 0.1 to 0.5 μm and soluble particles having an average particle size of 1 to 3 μm. In this case, a roughened surface having a more complicated shape can be formed. In the present invention, the particle size of the soluble particles is the length of the longest portion of the soluble particles.

Examples of the soluble resin particles include those made of a thermosetting resin, a thermoplastic resin, and the like. When immersed in a solution containing an acid or an oxidizing agent, the soluble resin particles have a higher dissolution rate than the hardly soluble resin. If it is, there is no particular limitation. Specific examples of the soluble resin particles include, for example, those made of epoxy resin, phenol resin, polyimide resin, polyphenylene resin, polyolefin resin, fluororesin, etc., and those made of one of these resins. Or a mixture of two or more resins. When such a soluble resin particle is used as the soluble particle, its particle size is 0.1 to 5 μm.
It is desirable that

Further, as the soluble resin particles, resin particles made of rubber can also be used. Examples of the rubber include polybutadiene rubber, various modified polybutadiene rubbers such as epoxy-modified, urethane-modified, (meth) acrylonitrile-modified, and (meth) acrylonitrile-butadiene rubber containing a carboxyl group. By using these rubbers, the soluble resin particles are easily dissolved in an acid or an oxidizing agent. In other words, when dissolving the soluble resin particles using an acid, an acid other than a strong acid can be dissolved, and when dissolving the soluble resin particles using an oxidizing agent, permanganese having a relatively weak oxidizing power is used. It can also dissolve in acids. Even when chromic acid is used, it can be dissolved at a low concentration. for that reason,
Acid or oxidizing agent does not remain on the resin surface, and as described later, after forming a roughened surface, when a catalyst such as palladium chloride is applied, the catalyst is not applied or the catalyst is oxidized. Nothing.

Examples of the above-mentioned soluble inorganic particles include particles made of at least one selected from the group consisting of aluminum compounds, calcium compounds, potassium compounds, barium compounds, magnesium compounds and silicon compounds.

Examples of the aluminum compound include alumina and aluminum hydroxide. Examples of the calcium compound include calcium carbonate and
Calcium hydroxide and the like, as the potassium compound, potassium carbonate and the like, as the barium compound, barium carbonate and the like, and as the magnesium compound, magnesia, dolomite, basic magnesium carbonate and the like. Examples of the silicon compound include silica and zeolite. These may be used alone or in combination of two or more. Of these, silicon compounds are desirable, and silica is particularly desirable. When an interlayer resin insulating layer is formed using a resin film containing such soluble inorganic particles, and a roughened surface is formed on the surface of the interlayer resin insulating layer using an acid or an oxidizing agent,
As described later, in addition to the action of dissolving the soluble inorganic particles, the roughened surface is also formed by the action of the soluble inorganic particles falling off. Therefore, in this case, a roughened surface can be formed on the surface of the interlayer resin insulating layer in a short time, and therefore, there is less possibility of adversely affecting the interlayer resin insulating layer.

As the above-mentioned soluble inorganic particles, it is desirable to use two or more kinds of soluble inorganic particles in combination. As a combination of the soluble inorganic particles used by mixing, a combination of the soluble inorganic particles relatively easily dissolved in the acid or the oxidizing agent and the soluble inorganic particles easily dropped off by the acid or the oxidizing agent is desirable. By using such a combination of soluble inorganic particles, a roughened surface having a more complicated shape can be formed. Further, it is desirable to use particles having different particle sizes in combination as the soluble inorganic particles. For example,
For example, soluble inorganic particles having an average particle size of about 2 μm and soluble inorganic particles having an average particle size of 0.5 to 1.5 μm are used in combination. Thereby, a roughened surface having a more complicated shape can be formed. Therefore, when a multilayer printed wiring board is manufactured using a resin film containing such inorganic particles,
The interlayer resin insulation layer and the conductor circuit have excellent adhesion.

The soluble metal particles include, for example,
Copper, nickel, iron, zinc, lead, gold, silver, aluminum,
Examples include particles made of at least one selected from the group consisting of magnesium, calcium, and silicon. These soluble metal particles may have a surface layer coated with a resin or the like in order to ensure insulation.

The above-mentioned soluble particles may be used alone, but it is desirable to use a mixture of two or more. By using a combination of two or more soluble particles, a roughened surface having a more complicated shape can be formed. In this case, the combination of the two types of soluble particles used as a mixture is preferably a combination of resin particles and inorganic particles.

This is because, when resin particles and inorganic particles are used in combination, a roughened surface having a complicated shape can be formed due to a difference in a dissolution process using an acid or an oxidizing agent. That is, since the soluble resin particles are the same resin as the hardly soluble resin, they have some compatibility with the hardly soluble resin, have a high affinity with the hardly soluble resin, and are completely dissolved by the oxidizing agent and the like. Before the dissolution, the soluble resin particles do not peel off from the layer of the poorly soluble resin, and the size of the formed concave portion also increases in proportion to the immersion time, and the concave portion having the same wall surface as the contour of the resin particle is difficult to be formed. . On the other hand, the soluble inorganic particles are particles of a different kind from the poorly soluble resin, and have no affinity or compatibility with the poorly soluble resin, so that when the soluble inorganic particles are dissolved by an oxidizing agent or the like, The soluble inorganic particles begin to dissolve from the interface between the soluble inorganic particles and the poorly soluble resin, and even when the inorganic particles are not completely dissolved, the soluble inorganic particles are peeled off from the poorly soluble resin, and when a certain size is reached, the soluble inorganic particles fall off. As a result, a concave portion having the same wall surface as the contour of the resin particles is formed. Therefore, the shape of the roughened surface formed through such different melting processes becomes more complicated. In particular, when silica is used as the soluble inorganic particles, since a concave portion having a completely different shape from the concave portion formed by the resin particles can be formed, a roughened surface having a more complicated shape can be formed. it can.

When the resin particles and the inorganic particles are used together, both have low conductivity, so that the insulating property of the resin film can be ensured, and the thermal expansion can be adjusted between the resin film and the poorly soluble resin. Easy to plan. Therefore, when a multilayer printed wiring board in which an interlayer resin insulating layer is formed using the resin film is manufactured, the obtained multilayer printed wiring board includes:
Cracks hardly occur in this interlayer resin insulation layer,
Separation hardly occurs between the interlayer resin insulating layer and the conductor circuit.

The hardly soluble resin can maintain the shape of the roughened surface when the roughened surface is formed on the interlayer resin insulating layer by using an acid or an oxidizing agent. A resin composite comprising at least one type of thermoplastic resin. By using such a resin composite as the hardly-soluble resin, as described above, when attaching the resin film, it is possible to simultaneously obtain conformability to a roughened surface and the like and shape retention. .

Examples of the thermosetting resin include amino resins such as phenol resin, melamine and urea resin, epoxy resin, epoxy-modified polyimide resin, unsaturated polyester resin, polyimide resin, urethane resin, diallyl phthalate resin and polyphenylene resin. , A polyolefin resin, a fluororesin and the like. The resin composite contains two types of such thermosetting resins. Further, the two types of thermosetting resins contained in the resin composite are:
Preferably, one of them is an epoxy resin,
A combination of an epoxy resin and a phenol resin or a combination of an epoxy resin and a polyimide resin is more desirable.

Specific examples of the epoxy resin include cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, alkylphenol novolak type epoxy resin, biphenol F type epoxy resin, Examples include a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin, an epoxidized product of a condensate of a phenol and an aromatic aldehyde having a phenolic hydroxyl group, triglycidyl isocyanurate, and an alicyclic epoxy resin. These may be used alone or in combination of two or more. Thereby, it becomes more excellent in heat resistance and the like. Among these, 1
An epoxy resin having two or more epoxy groups in the molecule is more desirable. Not only is it suitable for forming a roughened surface of a desired shape, it is also excellent in heat resistance etc.
In a multilayer printed wiring board formed using a resin film containing such an epoxy resin, cracks may occur in the interlayer resin insulating layer even under heat cycle conditions,
Separation hardly occurs between the interlayer resin insulating layer and the conductor circuit.

When two kinds of such thermosetting resins are contained in the above resin composite, the resin composite can simultaneously secure different characteristics. Specifically, for example, when an epoxy resin and a phenol resin are included, the resin composite has excellent mechanical properties such as crack resistance due to the presence of the epoxy resin, and metal due to the presence of the phenol resin. The adhesion to the layer is excellent. In this case, by using a phenol resin having a triazine structure as the phenol resin, more excellent adhesion to the metal layer can be obtained. Further, when the resin composite contains an epoxy resin and a polyimide resin as the thermosetting resin, as described above, excellent mechanical properties such as crack resistance due to the presence of the epoxy resin, as well as the polyimide resin, Due to its presence, it has excellent heat resistance. Further, as described above, by selecting two kinds of thermosetting resins having different affinities with the thermoplastic resin, localization of the thermoplastic resin is prevented, and the thermosetting resin and the thermoplastic resin are separated. It is possible to form a completely compatible resin film, and to reduce the stress generated when curing a thermosetting resin with a low curing temperature by selecting thermosetting resins with different curing temperatures. Can be. Such an effect is, for example, specifically, epoxy resin / phenol resin / polyether sulfone, polyimide resin / phenol resin / polyether sulfone, epoxy resin / phenol resin / phenoxy resin, polyimide resin / phenol resin / phenoxy resin. It can be obtained by using a resin composite composed of a combination of the above.

Examples of the thermoplastic resin include polyethersulfone, polysulfone, phenoxy resin, polyetherimide resin, polystyrene, polyethylene,
Examples thereof include polyacrylate, polyamideimide, polyphenylene sulfide, polyether ether ketone, polyoxybenzoate, polyvinyl chloride, polyacetal, and polycarbonate. These thermoplastic resins may be used alone or in combination of two or more.
Of these, phenoxy resin, polyether sulfone, polysulfone, and the like are desirable, and phenoxy resin is more desirable. This is because the phenoxy resin is relatively soft among these resins, layer separation hardly occurs even when combined with any thermosetting resin, and cracks and the like hardly occur in the formed interlayer resin insulating layer. is there. The mixing ratio of the thermosetting resin and the thermoplastic resin in such a resin film is desirably 10: 1 to 5 by weight. This is because the characteristics described above, that is, the followability and the shape retention can be simultaneously secured.

In the resin film of the present invention, the soluble particles are desirably substantially uniformly dispersed in the hardly-soluble resin. It is possible to form a roughened surface having unevenness of uniform roughness, and even if a via hole or a through hole is formed in a resin film, it is possible to secure adhesion to a conductor circuit formed thereon. It is. Alternatively, a resin film containing soluble particles only in the surface layer forming the roughened surface may be used. Thereby, since the portions other than the surface layer of the resin film are not exposed to the acid or the oxidizing agent, the insulation between the conductor circuits via the interlayer resin insulating layer is reliably maintained.

In the above resin film, the compounding amount of the soluble particles dispersed in the poorly soluble resin is preferably 3 to 40% by weight based on the resin film. If the amount of the soluble particles is less than 3% by weight, it may not be possible to form a roughened surface having desired irregularities. If the amount exceeds 40% by weight, the soluble particles may be dissolved using an acid or an oxidizing agent. In addition, there is a case where the resin film is melted to a deep portion of the resin film and the insulation between the conductor circuits via the interlayer resin insulating layer made of the resin film cannot be maintained, which may cause a short circuit.

The resin film desirably contains a curing agent and other components in addition to the soluble particles and the hardly soluble resin. As the curing agent, for example,
Imidazole-based curing agents, amine-based curing agents, guanidine-based curing agents, epoxy adducts of these curing agents and microcapsules of these curing agents, and organic materials such as triphenylphosphine, tetraphenylphosphonium, and tetraphenylborate. Phosphine compounds and the like can be mentioned.

The content of the curing agent is desirably 0.05 to 10% by weight based on the resin film. 0.
If the amount is less than 05% by weight, the resin film is insufficiently cured, so that the degree of penetration of the acid or the oxidizing agent into the resin film is increased, and the insulating property of the resin film may be impaired. On the other hand, when the content exceeds 10% by weight, an excessive curing agent component may modify the composition of the resin, which may cause a decrease in reliability.

Examples of the other components include fillers such as inorganic compounds and resins which do not affect the formation of the roughened surface. As the inorganic compound, for example,
Examples of the resin include silica, alumina, and dolomite. Examples of the resin include a polyimide resin, a polyacryl resin, a polyamideimide resin, a polyphenylene resin, a melanin resin, and an olefin resin. By including these fillers, matching of thermal expansion coefficient, improvement in heat resistance, chemical resistance, and the like can be achieved, and thus, performance of a multilayer printed wiring board manufactured using a resin film can be improved. .

Further, the resin film may contain a solvent. As the solvent, for example, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone,
Ethyl acetate, butyl acetate, cellosolve acetate, and aromatic hydrocarbons such as toluene and xylene. These may be used alone or in combination of two or more.

The resin film of the present invention can be produced, for example, by the following method. That is, first, a resin film-forming composition in which soluble particles and a hardly soluble resin are mixed with a curing agent and the like, if necessary, is prepared to uniformly dissolve the soluble particles in the hardly soluble resin. Next, the resin film forming composition is placed in a mold, dried and semi-cured to obtain a resin film. Instead of putting the resin film forming composition into a mold, PET
A resin film forming composition may be applied to a release film such as a film using a roll coater or the like, and then dried and semi-cured to form a resin film.
Note that a metal layer such as a copper foil may be formed on one side of the molded resin film.

Such a resin film is used for manufacturing a multilayer printed wiring board in which a conductor circuit and an interlayer resin insulating layer are sequentially laminated on a substrate. A multilayer film manufactured using this resin film is used. The printed wiring board cracks even under heat cycle conditions,
An interlayer resin insulating layer is formed in which peeling between the conductive circuit and the conductive circuit is unlikely to occur, and which has different characteristics such as excellent heat resistance and adhesion to the conductive circuit.

Next, a method for manufacturing a multilayer printed wiring board according to the present invention will be described. The method of manufacturing a multilayer printed wiring board of the present invention is a method of manufacturing a multilayer printed wiring board in which a conductive circuit and an interlayer resin insulating layer are sequentially laminated on a substrate, and when forming the interlayer resin insulating layer, A non-through hole and / or a through hole is formed by using the resin film of the present invention and pressing the resin film under a reduced pressure or vacuum under a pressure of 0.2 to 1 MPa.

According to the method for manufacturing a multilayer printed wiring board of the present invention, since the resin film of the present invention is used,
After forming the interlayer resin insulating layer, a roughened surface having desired irregularities can be formed on the surface thereof, and even under heat cycle conditions, cracks occur or peeling occurs with the conductor circuit. It is possible to form an interlayer resin insulating layer having excellent shape retention even when a through hole or a non-through hole is formed. Further, according to the manufacturing method of the present invention, it is possible to form an interlayer resin insulating layer having a plurality of different properties (for example, mechanical properties and adhesion to a conductor circuit).

Hereinafter, a method for manufacturing a multilayer printed wiring board according to the present invention will be described in the order of steps. (1) In the manufacturing method of the present invention, first, a substrate having a conductive circuit formed on a surface of an insulating substrate is prepared. As the insulating substrate, a resin substrate is desirable, and specifically,
Examples include a glass epoxy substrate, a polyester substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a thermosetting polyphenylene ether substrate, a fluororesin substrate, a copper-clad laminate, and an RCC substrate. At this time, if necessary, a through-hole may be provided in the insulating substrate. In this case, the through-hole is desirably formed using a drill having a diameter of 100 to 300 μm, a laser beam, or the like.

(2) Next, after performing electroless plating, a conductive circuit-shaped etching resist is formed on the substrate, and etching is performed to form a conductive circuit. Copper plating is desirable as the electroless plating. Also, when a through hole is provided in the insulating substrate, by simultaneously applying electroless plating to the wall surface of the through hole to form a through hole, the conductor circuits on both surfaces of the substrate are electrically connected. You may.

Further, after the electroless plating, when the surface of the electroless plating layer and the through-hole are formed, it is preferable to perform a roughening treatment on the inner wall of the through-hole to make the surface of the conductor circuit a roughened surface. . Examples of the roughening forming treatment method include blackening (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, Cu-Ni-P
Processing by needle-like alloy plating and the like can be mentioned.

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

As the etchant used for the above etching treatment, a mixed solution of an organic acid and a cupric complex is desirable. Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,
Maleic acid, benzoic acid, glycolic acid, lactic acid, malic acid, sulfamic acid and the like can be mentioned. These may be used alone or in combination of two or more. In the etching solution, the content of the organic acid is desirably 0.1 to 30% by weight. This is because the solubility of the oxidized copper can be maintained and the stability of the catalyst can be ensured.

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

As the plating treatment, for example, copper sulfate (1 to 40 g / l), nickel sulfate (0.1 to 6.0 g)
/ L), citric acid (10-20 g / l), sodium hypophosphite (10-100 g / l), boric acid (10-40 g / l)
g / l) and a surfactant (Surfynol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (0.01 to 10 g / l).
= 9 in the electroless plating bath, Cu-
A method of forming a roughened layer made of a Ni-P alloy is exemplified. This is because the crystal structure of the plating film deposited in this range has a needle-like structure, and thus has an excellent anchor effect.
The above-mentioned compound may be added to the electroless plating bath to add a complexing agent or an additive. Such a roughened surface may be formed as needed, and the next step may be performed without making the surface of the conductor circuit a roughened surface.

When a through hole is formed in this step, a resin filler is filled in the through hole. Further, if necessary, the resin filler is filled in the concave portion where the lower conductive circuit of the insulating substrate is not formed, and then the surface of the lower conductive circuit and the resin filler are flattened by polishing or the like. Good.

When a resin filler is filled in the through hole, the resin filler is dried, for example, at 100 ° C. for 20 minutes, and then cured. Curing is performed at a temperature of 50-2.
It is desirable to carry out between 50 ° C. As an example of this curing condition, after heating at 100 ° C. for 1 hour,
For example, there is a method of heating for a time. If necessary, step curing may be performed in which the temperature is gradually changed from a low temperature to a high temperature to cure.

When the surface of the lower conductor circuit or the like is flattened by polishing, the lower conductor circuit may be subjected to another roughening treatment as required. As the roughening treatment method,
Examples include blackening (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, treatment with Cu-Ni-P alloy plating, and the like.

(3) Next, an uncured (semi-cured) resin film layer is formed by pressing the resin film of the present invention on the substrate on which the conductive circuit is formed. The compression bonding of the resin film is performed using a device such as a vacuum laminator under reduced pressure or vacuum at a pressure of 0.2 to 1 MPa.

The pressure at the time of pressing the above resin film is
When the pressure is less than 0.2 MPa, the adhesion between the conductor circuit formed under the resin film layer and the resin film layer is low, and when the interlayer resin insulation layer is formed, the gap between the interlayer resin insulation layer and the conductor circuit is low. When peeling occurs or when the roughened surface is formed by using an acid or an oxidizing agent on the interlayer resin insulating layer in which the via hole opening or the like is formed, the acid or the oxidizing agent is removed from near the bottom surface of the via hole opening. It may easily enter the interface between the interlayer resin insulation layer and the conductor circuit, which may cause peeling between the two. On the other hand, when the pressure at the time of pressing the resin film is 1
If it exceeds MPa, a portion where the soluble particles are aggregated in the surface layer portion of the interlayer resin insulating layer occurs, and when the aggregated soluble particles are dissolved or dropped, irregularities of a desired shape are formed on the roughened surface. And the adhesion strength between the interlayer resin insulation layer and the conductor circuit formed on the interlayer resin insulation layer is 0.5
kg or less, and peeling of the conductor circuit is likely to occur.

The pressure at the time of pressing the resin film is as follows:
0.3-0.7 MPa is desirable. This makes it possible to form a roughened surface having uniform irregularities regardless of the size and density of the soluble particles, and to maintain a desired adhesion strength between the interlayer resin insulating layer and the conductor circuit. This is because peeling does not occur between the interlayer resin insulating layer and the conductor circuit.

The pressure bonding of the resin film is preferably performed under heating, more preferably at a temperature of 40 to 70 ° C. When the heating temperature is less than 40 ° C., the effect of heating is hardly obtained, and when the heating temperature exceeds 70 ° C., when the resin film contains a curing agent or a solvent, these curing agents or solvents volatilize, It may be denatured and cured insufficiently, or the curing may progress too much and resin may remain as a residue on the bottom of the via hole opening, lowering the connection reliability of the conductor circuit including the via hole. Sometimes.

A more desirable heating temperature is 50 to 60 ° C. This is because the soluble particles in the resin film do not agglomerate, and the curing agent and other components contained in the resin film do not volatilize or denature before curing.

The time for pressing the resin film is preferably 10 to 120 seconds. If the crimping time is less than 10 seconds, the crimping of the resin film is insufficient, while if the crimping time exceeds 120 seconds, the adhesion between the resin film and the conductor circuit is hardly improved.

It is desirable that the degree of vacuum when the resin film is pressure-bonded is 13 to 1300 Pa. It is technically not easy to reduce the degree of vacuum to less than 13 Pa, and it takes time. On the other hand, if it exceeds 1300 Pa, the resin film may not be completely filled between the conductor circuits having a wiring interval of less than 50 μm.

(6) Next, a hardening treatment is applied to the uncured resin film layer, and a non-through hole and / or a through hole is formed to form an interlayer resin insulating layer. In this step, a through-hole may be formed as necessary. The non-through hole is, for example, an opening for a via hole, and the through hole is, for example, a through hole for a through hole.

The via hole opening is desirably formed by laser processing. The laser processing may be performed before the curing processing or may be performed after the curing processing. Further, depending on the material of the resin film layer and the diameter of the opening to be formed, the opening for the via hole may be provided by performing exposure and development processing. In this case, the exposure and development processes are performed before the above-described curing process.

Examples of the laser used in the laser processing include a carbon dioxide gas laser, an excimer laser, a UV laser, and a YAG laser. These lasers may be selectively used in consideration of the shape of a via hole opening or a through hole to be formed.

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

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

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

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

The thickness of the interlayer resin insulation layer is not particularly limited, but is preferably 5 to 50 μm. The thickness is 5
If it is less than μm, insulation between the vertically adjacent conductor circuits may not be maintained, while if it exceeds 50 μm,
When a non-through hole or the like is formed, resin residue may be generated at the bottom thereof, or the shape of the non-through hole or the like may be tapered toward the bottom.

Further, on the substrate on which the interlayer resin insulating layer is formed,
When forming a through hole, the through hole is formed using a drill having a diameter of 50 to 300 μm, laser light, or the like. When the through-hole is formed, in a step described later, by forming a conductor layer on the inner wall surface of the through-hole, the through-hole can be formed, and by forming the through-hole,
Conductive circuits can be electrically connected via the substrate and the interlayer resin insulating layer.

(7) Next, if necessary, the surface of the interlayer resin insulating layer including the inner wall of the via hole opening and the inner wall of the through hole when the through hole is formed in the above-described step, may be acid or oxidized. A roughened surface is formed using an agent. Examples of the acid include sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, and formic acid. Examples of the oxidizing agent include chromic acid, chromic sulfuric acid, and permanganates such as sodium permanganate. When the interlayer resin insulating layer is formed using a resin film containing a phenoxy resin, it is desirable to form a roughened surface using the above permanganate.

Thereafter, when the roughened surface is formed by using an acid, an aqueous solution of an alkali or the like is used, and when the roughened surface is formed by using an oxidizing agent, a neutralizing solution is used. Neutralizes the inside of the through hole. By this operation, the acid and the oxidizing agent are removed so that the next step is not affected.

(8) Next, a catalyst is applied to the formed roughened surface, if necessary. Examples of the catalyst include palladium chloride. At this time, in order to reliably apply the catalyst, a dry treatment such as a plasma treatment with oxygen, nitrogen or the like or a corona treatment is performed to remove a residue of an acid or an oxidizing agent and to modify the surface of the interlayer resin insulating layer. By doing so, the catalyst can be reliably applied, the metal can be deposited during electroless plating, and the adhesion of the electroless plating layer to the interlayer resin insulating layer can be improved. In particular, the bottom surface of the via hole opening can be improved. In the above, a great effect can be obtained.

(9) Next, a thin film conductor layer is formed on the surface of the interlayer resin insulating layer including the inner wall surface of the via hole opening. The thin film conductor layer is desirably formed by electroless plating, but may be formed by a method such as sputtering or vapor deposition. Examples of the material of the thin film conductor layer include copper and nickel alloys thereof. Among them, copper is desirable from the viewpoint of electric characteristics and economy.

The thickness of the thin film conductor layer formed by the electroless plating is desirably 0.3 to 2.0 μm. When the thickness of the thin film conductor layer is less than 0.3 μm, a thin film conductor layer having a flat upper surface cannot be formed. On the other hand, when the thickness exceeds 2.0 μm, when the thin film conductor layer is removed in a later step, The thin film conductor layer may remain on the surface of the interlayer resin insulating layer.

When the through-hole is formed in the step (6), a through-hole may be formed by forming a thin film conductor layer made of metal also on the inner wall surface of the through-hole in this step.

When a through hole is formed in the step (6), it is desirable to perform the following processing steps. That is, the surface of the electroless plating layer and the inner wall of the through hole are subjected to blackening (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, treatment with Cu-Ni-P needle-like alloy plating, or the like. To perform a roughening process. Thereafter, the inside of the through-hole is further filled with a resin filler or the like, and then the surface portion of the resin filler and the surface of the electroless plating layer are flattened by a polishing treatment method such as buffing. Further, electroless plating is performed, and an electroless plating layer is formed on the already formed thin film conductor layer made of metal and the surface layer of the resin filler, thereby forming a lid plating layer on the through hole.

(10) Next, a plating resist is formed on a part of the interlayer resin insulating layer using a dry film,
Thereafter, electroplating is performed using the thin film conductor layer as a plating lead, and an electroplating layer is formed in the portion where the plating resist is not formed. At this time, the via hole opening may be filled with electroplating to form a field via structure, and after filling the via hole opening with a conductive paste or the like, a lid plating layer may be formed thereon to form a field via structure. Good. By forming a field via structure, a via hole can be provided immediately above the via hole.

(11) After the formation of the electroplating layer, the plating resist is peeled off, and the thin film conductor layer made of a metal existing under the plating resist is removed by etching.
Independent conductor circuits. Examples of the etchant include a sulfuric acid-hydrogen peroxide aqueous solution, ammonium persulfate, sodium persulfate, a persulfate aqueous solution such as potassium persulfate,
An aqueous solution of ferric chloride and cupric chloride, hydrochloric acid, nitric acid, hot dilute sulfuric acid and the like can be mentioned. Alternatively, a roughened surface may be formed simultaneously with etching between conductor circuits using an etching solution containing the above-described cupric complex and an organic acid. Further, if necessary, the catalyst may be removed from the interlayer resin insulating layer using an acid or an oxidizing agent. By removing the catalyst, the metal such as palladium used for the catalyst disappears, so that a decrease in electric characteristics can be prevented.

(12) Thereafter, the above steps (3) to (11) are repeated as necessary to produce a substrate on which the conductor circuit and the interlayer resin insulating layer are sequentially laminated.

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

When the above PGA is provided, it is desirable to connect a pin made of an alloy such as Kovar or 42 alloy through a conductive adhesive layer such as a solder paste. Mold pins are preferred.

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

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

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

The solder resist composition may contain an elastomer or an inorganic filler. By being blended with the elastomer, the formed solder resist layer can absorb or reduce the stress even when a stress acts on the solder resist layer due to the flexibility and rebound resilience of the elastomer. As a result, cracks and peeling can be suppressed from occurring in the manufacturing process of the multilayer printed wiring board and in the solder resist layer after mounting electronic components such as IC chips on the manufactured multilayer printed wiring board. Even when it occurs, the crack does not grow large.

The method of opening the solder resist layer includes, for example, a method of irradiating a laser beam as in the method of forming an opening for a via hole.

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

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

A plasma treatment with oxygen, carbon tetrachloride, or the like may be performed as needed for a character printing step for forming product recognition characters or the like or for modifying a solder resist layer. Although the above method is based on the semi-additive method, a full additive method may be employed.

[0099]

The present invention will be described in more detail below. Example 1 A. Preparation of resin film Bisphenol A type epoxy resin (Epoxy equivalent 18
5, Yuka Shell Epoxy Epicoat 828EL)
30 parts by weight, 30 parts by weight of a triazine structure-containing phenol novolak resin (triazine: phenol = 1: 9, phenolite LA-7052, manufactured by Dainippon Ink and Chemicals, Inc.) to 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha Heat and dissolve with stirring, and polyether sulfone (PES) (Mitsui Chemicals)
8 parts by weight, terminal epoxidized polybutadiene rubber 15 parts by weight, 2-phenyl-4,5-bis (hydroxymethyl)
A resin composition was prepared by adding 1.5 parts by weight of a pulverized imidazole and 0.5 parts by weight of a silicone-based antifoaming agent. After applying the obtained resin composition on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, the resin film is dried at 80 to 120 ° C. for 10 minutes to obtain a resin film. Produced.

B. Preparation of resin filler 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., molecular weight: 310, YL983U), the average particle diameter of which is coated with a silane coupling agent on the surface is 1.6 μm, and the diameter of the largest particle Is less than 15 μm
iO ₂ spherical particles (CRS 1101- manufactured by Adtech Co., Ltd.)
CE) 170 parts by weight and 1.5 parts by weight of a leveling agent (Perenol S4 manufactured by San Nopco Co.) are placed in a container, and the mixture is stirred and mixed to have a viscosity of 45-4 at 23 ± 1 ° C.
A resin filler of 9 Pa · s was prepared. In addition, as a curing agent, an imidazole curing agent (2E4MZ- manufactured by Shikoku Chemicals Co., Ltd.)
6.5 parts by weight (CN).

C. Method for manufacturing printed wiring board (1) 0.8 mm thick glass epoxy resin or BT
A starting material was a copper-clad laminate in which 18 μm copper foils 8 were laminated on both sides of a substrate 1 made of (bismaleimide-triazine) resin (see FIG. 1A). First, this copper clad laminate is drilled and subjected to electroless plating.
The lower conductor circuit 4 and the through hole 9 were formed on both surfaces of the substrate 1 by etching in a pattern.

(2) The substrate on which the through hole 9 and the lower conductor circuit 4 are formed is washed with water and dried,
(10 g / l), NaClO ₂ (40 g / l), Na ₃
A blackening treatment using an aqueous solution containing PO ₄ (6 g / l) as a blackening bath (oxidizing bath), NaOH (10 g / l), Na
A reduction treatment was performed using an aqueous solution containing BH ₄ (6 g / l) as a reducing bath, and roughened surfaces 4 a and 9 a were formed on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 1 (b)). ).

(3) After preparing the resin filler described in the above B, within 24 hours after preparation by the following method, the conductive circuit non-formed portion and the conductive circuit in the through hole 9 and on one side of the substrate 1 A layer of the resin filler 10 was formed on the outer edge portion of No. 4. That is, first, the resin filler was pushed into the through holes using a squeegee, and then dried at 100 ° C. for 20 minutes. Next, a mask having an opening corresponding to the conductor circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed in the conductor circuit non-forming portion having a concave portion using a squeegee. At 20 ° C. for 20 minutes (FIG. 1).
(C)).

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

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

(5) After the above substrate is washed with water and acid degreased,
Soft etching is performed, and then an etching solution is sprayed on both surfaces of the substrate to etch the surface of the lower conductive circuit 4 and the land surface and the inner wall of the through-hole 9, so that the entire surface of the lower conductive circuit 4 is roughened. Surface 4a, 9a
Was formed (see FIG. 2A). As an etching solution, an etching solution (Mec etch bond, manufactured by Mec Co., Ltd.) comprising 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride was used.

(6) On both surfaces of the substrate, a resin film for an interlayer resin insulating layer slightly larger than the substrate prepared in A was placed on the substrate, and the pressure was 4 kgf / cm ² , the temperature was 80 ° C., and the pressure bonding time was 10 seconds. After temporary compression bonding under the conditions and cutting, an interlayer resin insulating layer was formed by bonding using a vacuum laminator by the following method (see FIG. 2B). That is, a resin film for an interlayer resin insulation layer is placed on a substrate, with a degree of vacuum of 65 Pa, a pressure of 0.4 MPa, a temperature of 80 ° C.,
The main press was performed under the condition of a press contact time of 60 seconds, and thereafter, thermosetting was performed at 170 ° C. for 30 minutes.

(7) Next, a CO ₂ gas laser having a wavelength of 10.4 μm is used to form a beam having a beam diameter of 4.0 through a mask having a through hole having a thickness of 1.2 mm formed on the interlayer resin insulating layer 2.
2 mm, a top hat mode, a pulse width of 8.0 μsec, a mask through-hole diameter of 1.0 mm, and a one-shot condition, a via hole opening 6 having a diameter of 80 μm was formed in the interlayer resin insulating layer 2 (FIG. c)).

(8) The substrate having the via hole opening 6 formed therein is immersed in a solution containing 60 g / l of permanganic acid at 80 ° C. for 10 minutes to remove the epoxy resin particles present on the surface of the interlayer resin insulating layer 2. By dissolving and removing, the surface of the interlayer resin insulating layer 2 including the inner wall of the via hole opening 6 was roughened (see FIG. 2D).

(9) Next, the substrate after the above treatment was immersed in a neutralizing solution (manufactured by Shipley) and washed with water. Further, by applying a palladium catalyst to the surface of the substrate subjected to the surface roughening treatment (roughening depth: 3 μm), a catalyst nucleus is attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6. Was.

(10) Next, the substrate is immersed in an electroless copper plating aqueous solution having the following composition, and the thickness of the substrate is reduced to 0.6 to
A 3.0 μm electroless copper plating film 12 was formed (FIG. 3).
(A)). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l tartaric acid 0.200 mol / l copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α'-bipyridyl 40 mg / l Polyethylene glycol (PEG) 0.10 g / l [Electroless plating conditions] 40 minutes at a liquid temperature of 35 ° C

(11) A commercially available photosensitive dry film is stuck on the electroless copper plating film 12 and a mask is placed thereon to
Exposure was performed at 00 mJ / cm ² , and development was performed with a 0.8% aqueous sodium carbonate solution to provide a plating resist 3 having a thickness of 30 μm (see FIG. 3B).

(12) Then, the substrate was washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions to give a thickness of 20 μm.
m of the electrolytic copper plating film 13 was formed (see FIG. 3C). [Electroplating aqueous solution] sulfuric acid 2.24 mol / l copper sulfate 0.26 mol / l additive 19.5 ml / l (manufactured by Atotech Japan, Capparaside HL) [electroplating conditions] current density 1 A / dm ² hours 65 minutes Temperature 22 ± 2 ℃

(13) Plating resist 3 is made of 5% NaOH
Then, the electroless plating film 12 under the plating resist 3 is dissolved and removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and the thickness of the electroless plating film 12 and the electrolytic copper plating film 13 is reduced. A conductor circuit (including the via hole 7) 5 having a thickness of 18 μm was formed (see FIG. 3D).

(14) The same treatment as in (5) was performed, and a roughened surface was formed with an etching solution containing a cupric complex and an organic acid (see FIG. 4A).

(15) By repeating the above steps (6) to (14), a conductor circuit of a further upper layer was formed, and a multilayer wiring board was obtained (see FIGS. 4 (b) to 5 (b)). .

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

(17) Next, the solder resist composition is applied on both surfaces of the multilayer wiring board in a thickness of 20 μm.
After performing a drying process under the conditions of 70 ° C. for 20 minutes and 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the solder resist opening is drawn is brought into close contact with the solder resist layer to form a 1000 mJ / cm ² . Exposure with ultraviolet light,
The film was developed with a DMTG solution to form an opening having a diameter of 200 μm. Then, at 80 ° C. for 1 hour, 100 ° C.
For 1 hour, at 120 ° C. for 1 hour, and at 150 ° C. for 3 hours to cure the solder resist layer, thereby forming a solder resist pattern layer 14 having an opening and a thickness of 20 μm. . As the solder resist composition, a commercially available solder resist composition can be used.

(18) Next, the substrate on which the solder resist layer 14 is formed is coated with nickel chloride (2.3 × 10 ^-1 mol).
/ L), sodium hypophosphite (2.8 × 10 ^-1 mol)
/ L), sodium citrate (1.6 × 10 ^-1 mol /
2) in the electroless nickel plating solution having pH = 4.5 containing l)
This was immersed for 0 minutes to form a nickel plating layer 15 having a thickness of 5 μm in the opening. Furthermore, the substrate gold potassium cyanide ^{(7.6 × 10 -3 mol / l} ), ammonium chloride ^{(1.9 × 10 -1 mol / l} ), sodium citrate (1.2 × 10 ^-1 mol / l), immersed in an electroless gold plating solution containing sodium hypophosphite (1.7 × 10 ^-1 mol / l) for 7.5 minutes at 80 ° C. A gold plating layer 16 of 0.03 μm was formed.

(19) Thereafter, a solder paste containing tin-lead is printed on the opening of the solder resist layer 14 on the surface of the substrate on which the IC chip is to be mounted, and the opening of the solder resist layer 14 on the other surface is further printed. After printing a solder paste containing tin-antimony on the substrate, a solder bump (solder body) 17 was formed by reflow at 200 ° C., and a multilayer printed wiring board having the solder bump 17 was manufactured (FIG. 5C). reference).

Example 2 A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a resin film produced by the following method was used. Preparation of resin film Bisphenol A type epoxy resin (Epoxy equivalent 18
5, Yuka Shell Epoxy Epicoat 828EL)
30 parts by weight, 30 parts by weight of a triazine structure-containing phenol novolak resin (triazine: phenol = 1: 9, phenolite LA-7052 manufactured by Dainippon Ink and Chemicals, Inc.) to 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha Heat and dissolve while stirring, and add phenoxy resin (YPB-40-PX manufactured by Toto Kasei Co., Ltd.)
M40) 5 parts by weight, a terminal epoxidized polybutadiene rubber 15 parts by weight, 2-phenyl-4,5-bis (hydroxymethyl) imidazole pulverized product 1.5 parts by weight, and a silicon-based antifoaming agent 0.5 parts by weight. A resin composition was prepared. After applying the obtained resin composition on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, the resin film is dried at 80 to 120 ° C. for 10 minutes to obtain a resin film. Produced.

Example 3 In the preparation of the resin film of Example 1, 15 parts by weight of epoxidized polybutadiene rubber was replaced with 15 parts by weight of finely divided silica (particle size: 0.5 μm).
A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a resin film was manufactured using parts by weight.

Example 4 In the preparation of the resin film of Example 2, finely ground silica (particle size: 0.5 μm) was replaced with 15 parts by weight of an epoxidized polybutadiene rubber.
A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a resin film was manufactured using parts by weight.

Example 5 A resin film was prepared in the same manner as in Example 1, except that 10 parts by weight of silicon (particle diameter: 1 μm) was used instead of 15 parts by weight of the epoxidized polybutadiene rubber. A multilayer printed wiring board was manufactured in the same manner as in Example 1.

Example 6 A resin film was prepared in the same manner as in Example 1, except that 10 parts by weight of silicon (particle diameter: 0.3 μm) was used instead of 15 parts by weight of the epoxidized polybutadiene rubber. Manufactured a multilayer printed wiring board in the same manner as in Example 2.

Example 7 A resin film was prepared in the same manner as in Example 1, except that 4 parts by weight of an epoxidized polybutadiene rubber and 2 parts by weight of finely ground silica (particle diameter 0.01 μm) were added. Manufactured a multilayer printed wiring board in the same manner as in Example 1.

Example 8 A resin film was prepared in the same manner as in Example 1, except that 3 parts by weight of an epoxidized polybutadiene rubber and 5 parts by weight of finely ground silica (particle size: 0.5 μm) were added. Manufactured a multilayer printed wiring board in the same manner as in Example 2.

Example 9 A resin film was prepared in the same manner as in Example 1, except that 2 parts by weight of a terminally epoxidized polybutadiene rubber and 10 parts by weight of silicon (particle diameter: 0.3 μm) were added. A multilayer printed wiring board was manufactured in the same manner as in Example 1.

Example 10 The procedure of Example 1 was repeated except that the resin film was prepared by adding 5 parts by weight of an epoxidized polybutadiene rubber and 3 parts by weight of silicon (particle diameter: 1 μm). In the same manner as in Example 2, a multilayer printed wiring board was manufactured.

The multilayer printed wiring boards obtained in Examples 1 to 10 were subjected to 1000 cycles of a reliability test at 130 ° C. for 3 minutes and at −65 ° C. for 3 minutes as one cycle. ) Peel strength, (2) presence or absence of cracks in interlayer resin insulation layer, (3) presence or absence of peeling between interlayer resin insulation layer and conductive circuit, (4) flatness of interlayer resin insulation layer (5) The shape of the via hole opening was evaluated. The results are shown in Table 1. Note that the above (2) to (5)
Was evaluated by cutting the multilayer printed wiring board with a blade and observing the cross section with a microscope. Also, (4)
Evaluations of (5) and (5) were performed only before the reliability test. The evaluation of (4) the flatness of the interlayer resin insulation layer and (5) the shape of the opening for the via hole was performed according to the following evaluation criteria.

[0131]Evaluation criteria  (4) Flatness of interlayer resin insulating layer On the upper surface of the interlayer resin insulating layer, a concave portion on the surface of the lower conductive circuit is formed.
No unevenness due to the protrusion is observed, and the lower conductor circuit type
Unevenness due to the difference in height between the component part and the part where the lower conductor circuit is not formed
Good if no swell is observed, otherwise bad
Was evaluated. (5) Shape of the opening for the via hole The shape of the cross section is preferably an inverted trapezoidal shape or a rectangular shape.
And other shapes, for example, asymmetrical distortion on the left and right walls
The one with a round shape was regarded as defective.

[0132]

[Table 1]

As shown in Table 1, the multilayer printed wiring boards manufactured in Examples 1 to 10 had a peel strength of 1.0 kg / cm or more even after the reliability test, and had a conductor circuit and interlayer resin insulation. Adhesion with the layer was sufficient. Before and after the reliability test, no cracks occurred in the interlayer resin insulating layer, and no peeling occurred between the interlayer resin insulating layer and the conductor circuit. In these multilayer printed wiring boards, the flatness of the interlayer resin insulating layer and the shape of the via hole opening were also good.

[0134]

As described above, in the resin film of the present invention, particles which are soluble in an acid or an oxidizing agent are dispersed in a resin which is hardly soluble in an acid or an oxidizing agent. Since a resin composite composed of two kinds of thermosetting resin and thermoplastic resin is used, when attaching the resin film, the surface of the substrate on which the conductor circuit is formed, including the conductor circuit surface, Excellent in conformity to shape and shape retention. In addition, the resin film can form an interlayer resin insulating layer that simultaneously secures different characteristics by curing. Further, in the resin film of the present invention, since the soluble particles are dispersed in the poorly soluble resin, a roughened surface having desired irregularities can be formed on the surface of the interlayer resin insulating layer. Therefore, according to the resin film of the present invention, even under heat cycle conditions, cracks are generated, peeling between the conductive circuit and the conductor circuit is less likely to occur, even when forming a through hole or a non-through hole. An interlayer resin insulation layer having excellent shape retention can be formed.

Further, according to the method for manufacturing a multilayer printed wiring board of the present invention, since the resin film of the present invention is used, after forming an interlayer resin insulating layer, a roughened surface having desired irregularities on its surface is formed. The surface can be formed, it is hard to crack under heat cycle conditions, and it does not peel off with the conductor circuit, and it retains shape even when forming through holes and non-through holes It is possible to form an interlayer resin insulating layer having excellent characteristics. Further, according to the manufacturing method of the present invention, it is possible to form an interlayer resin insulating layer having a plurality of different characteristics.

[Brief description of the drawings]

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

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

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Interlayer resin insulation layer 3 Plating resist 4 Lower conductor circuit 4a Roughened surface 5 Conductor circuit 6 Via hole opening 7 Via hole 8 Copper foil 9 Through hole 9a Roughened surface 10 Resin filler 12a Electroless copper plating layer 12b Electroless copper plating layer 13 Electrolytic copper plating film 14 Solder resist layer 15 Nickel plating film

Claims (6)

[Claims] 1. A resin film used for manufacturing a multilayer printed wiring board in which a conductive circuit and an interlayer resin insulating layer are sequentially laminated on a substrate, wherein the resin film has low solubility in an acid or an oxidizing agent. Particles soluble in an acid or an oxidizing agent are dispersed in the resin, and the hardly-soluble resin is a resin composite composed of two thermosetting resins and at least one thermoplastic resin. Characteristic resin film. 2. The resin film according to claim 1, wherein one of the thermosetting resins is an epoxy resin. 3. The resin film according to claim 1, wherein the two thermosetting resins are an epoxy resin and a phenol resin, or an epoxy resin and a polyimide resin. 4. The thermoplastic resin is a phenoxy resin,
4. The resin film according to claim 1, wherein the resin film is at least one selected from the group consisting of polyether sulfone and polysulfone. 5. The resin film according to claim 1, wherein the soluble particles are at least one selected from the group consisting of resin particles, inorganic particles, and metal particles. 6. A method for manufacturing a multilayer printed wiring board, wherein a conductive circuit and an interlayer resin insulation layer are sequentially laminated on a substrate, wherein the interlayer resin insulation layer is formed.
The resin film according to any one of the above, under a reduced pressure or vacuum, 0.2 to 1 MPa
Forming a non-through hole and / or a through hole after pressure bonding at a pressure of: