JP2002076610A - Etching liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etching liquid capable of forming a roughed surface having a uniform roughness on an overall surface of a conductor circuit without forming the circuit in an undercut shape. SOLUTION: The etching liquid is used in the case of manufacturing a multilayer printed circuit board in which a conductor circuit and a resin insulating layer are sequentially formed on a board. The liquid comprises a hydrogen peroxide, a sulfuric acid, a tetrazole and/or its derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching solution used for producing a multilayer printed wiring board.

[0002]

2. Description of the Related Art In recent years, with the increase in frequency of electric signals,
The material of the package substrate is required to have a low dielectric constant and a low dielectric loss tangent. Therefore, the mainstream of the material of the multilayer printed wiring board used for the package substrate is shifting from ceramic to resin.

Under such a background, a multilayer printed wiring board using a resin substrate is manufactured by a method disclosed in, for example, JP-A-4-55555. That is, first, a through hole is formed in the copper-clad laminate to which the copper foil is attached, 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 a roughened surface is formed on the surface of the conductor circuit by etching or the like. Then, after forming a resin insulation layer on the conductor circuit having the roughened surface, exposure and development are performed to form an opening for a via hole, and then an interlayer resin insulation layer is formed through UV curing and main curing. I do.

Further, after roughening the interlayer resin insulating layer with an acid or an oxidizing agent, a thin electroless plating layer is formed, and a plating resist is formed on the electroless plating layer.
Thickening is performed by electroplating, and after removing the plating resist, the thin electroless plating layer existing under the plating resist is removed using an etchant to form an independent conductor circuit, which is further oxidized (blackened). )-Reduction treatment,
A roughened surface is formed on the conductive circuit surface by Cu-Ni-P needle-like alloy plating or the like. After repeating this process, finally form a solder resist layer to protect the conductor circuit,
Furthermore, an opening is formed for connection with an IC chip or the like,
The production of the multilayer printed wiring board is completed by plating the exposed conductor circuits and printing solder paste to form solder bumps.

In such a method for manufacturing a multilayer printed wiring board, the roughened surface formed on the surface of the conductor circuit is for obtaining the adhesion between the conductor circuit and the resin insulating layer. However, when a roughened surface is formed on the conductor circuit surface by oxidation (blackening) -reduction treatment, there has been a problem that sufficient adhesion between the conductor circuit and the resin insulating layer cannot be obtained.

When a roughened surface is formed on the surface of a conductor circuit by Cu-Ni-P needle-like alloy plating or the like, a plating layer is formed not only on the surface of the conductor circuit but also on the surface of a lower resin insulation layer by plating. May be formed, and there is a problem that the plating layer formed on the surface of the resin insulating layer causes a short circuit.

[Problems to be solved by the invention]

In order to avoid such a problem, there has been proposed a method of forming a roughened surface on a conductive circuit surface by etching. In JP-A-11-87928, using an etching solution containing a cupric complex and an organic acid salt,
A multilayer printed wiring board having a roughened surface formed on the surface of a conductive circuit is disclosed. Japanese Patent Application Laid-Open No. Hei 10-96088 discloses a roughened surface formed on a conductive circuit surface by an etching solution comprising oxoacid, peroxide and azole. Are disclosed.

However, when a roughened surface is formed on the surface of a conductive circuit by using these methods, a roughened surface having unevenness of uniform roughness cannot be formed on the surface of the conductive circuit.
After forming a resin insulation layer on a conductor circuit and performing a reliability test, peeling may occur between the conductor circuit and the resin insulation layer.

When a roughened surface is formed on the surface of a conductor circuit by using the above method, the roughened surface is substantially parallel to the substrate surface so as to form a shadow when irradiated with a laser beam. Direction recesses may be formed. Therefore, when the resin insulating layer is formed on the conductive circuit and the laser light is irradiated to open the resin insulating layer, the concave portion is not irradiated with the laser light, and the resin residue is generated on the roughened surface. . As a result, when a metal layer is formed in the opening to provide a via hole, the conductive circuit and the metal layer do not adhere to each other due to the resin residue when the metal layer is formed. Sometimes
In some cases, the resin remaining on the upper surface of the conductive circuit swells and causes peeling of the conductive circuit from the metal layer.

[0010] As shown in FIG. 13, using an etching solution comprising oxo acid, peroxide and azole,
The surface of the conductor circuit 35 formed on the substrate 31 has a roughened surface 35.
When forming a, the azole is first adsorbed on the surface of the conductor circuit 35 formed on the substrate 31 (FIG. 13A).
reference). Thereafter, the unadsorbed portion of the azole is etched with oxo acid and peroxide, and a roughened surface is formed on the surface of the conductor circuit. However, when the roughened surface is formed using azole, a deep recess 35
b was formed, and the conductor circuit sometimes became an undercut shape (see FIGS. 13B and 13C). As shown in FIG. 14, the azole hardly adhered to the bottom side surface of the conductor circuit, so that the conductor It is considered that the side surface of the circuit bottom is excessively etched, which may be a cause of the undercut shape of the conductor circuit. Note that FIG.
(A) to (c) are cross-sectional views schematically showing a step of forming a roughened surface on a conductor circuit surface in a conventional manufacturing process of a multilayer printed wiring board, and FIG. 14 is a sectional view of FIG. 3 is a partially enlarged view of A in FIG.

When the conductor circuit has an undercut shape as described above, when an interlayer resin insulating layer is formed on the conductor circuit, the undercut portion is not filled with resin,
The adhesion between the undercut part and the resin is low,
Cracks may occur in the interlayer resin insulation layer, and peeling between the interlayer resin insulation layer and the conductor circuit may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an etching solution used for manufacturing a multilayer printed wiring board, in which a conductive circuit has an undercut shape. Another object of the present invention is to provide an etchant capable of forming a roughened surface having unevenness with a uniform roughness over the entire surface of a conductor circuit.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, an etching solution containing hydrogen peroxide, sulfuric acid, tetrazole and / or a derivative thereof has a rough surface on a conductive circuit surface. When forming a roughened surface, it was found that a roughened surface having unevenness with a uniform roughness could be formed and no undercut was formed, and the inventors reached an invention having the following content as a gist configuration.

That is, the etching solution of the present invention is used when manufacturing a multilayer printed wiring board in which a conductor circuit and a resin insulating layer are sequentially formed on a substrate, and is used for producing hydrogen peroxide, sulfuric acid, tetrazole and / or tetrazole. And a derivative.

In the etching solution of the present invention, the tetrazole derivative may be an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkylphenyl group having 7 to 20 carbon atoms, an amino group, or a phenyl group. , A mercapto group, an alkylmercapto group having 1 to 10 carbon atoms, or
It is desirable to have a carboxyalkyl group having 1 to 10 carbon atoms.

In the etching solution, the concentration of the hydrogen peroxide is 1 to 50 g / l, the concentration of the sulfuric acid is 1 to 50 g / l, and the concentration of the tetrazole and / or its derivative is , 0.1 to 30 g / l.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The etching solution of the present invention is used for manufacturing a multilayer printed wiring board in which a conductive circuit and a resin insulating layer are sequentially formed on a substrate, and is used for producing hydrogen peroxide, sulfuric acid, tetrazole and / or tetrazole. Or a derivative thereof (hereinafter, also referred to as a tetrazole compound).

According to the above-mentioned etching solution, when manufacturing a multilayer printed wiring board, a roughened surface having unevenness of uniform roughness is formed on the entire surface of the conductor circuit without forming the conductor circuit in an undercut shape. can do. This is presumed to be due to the following reasons.

That is, the above-mentioned etching solution etches the conductor circuit surface by the progress of the reactions shown in the following reaction formulas (1) to (3). Cu + H ₂ O ₂ + H ₂ SO ₄ → CuSO ₄ + 2H ₂ O (1) Cu + H ₂ O ₂ → CuO + H ₂ O (2) CuO + H ₂ SO ₄ → CuSO ₄ + H ₂ O (3) The above reaction formulas (1) to (3) show the reaction formulas of etching that proceed when the material forming the conductor circuit is copper.

However, in the reaction between copper and hydrogen peroxide or sulfuric acid, the entire surface of the conductor circuit is etched substantially uniformly, and a roughened surface cannot be formed on the surface of the conductor circuit. Therefore, the etching solution of the present invention contains a tetrazole compound.

FIGS. 1A to 1C are cross-sectional views schematically showing steps of forming a roughened surface on a conductor circuit surface using the etching solution of the present invention. It is the elements on larger scale of A in FIG. 1 (a).

Since the etching solution of the present invention contains a tetrazole compound, when the etching solution of the present invention comes into contact with a conductor circuit, first, the surface of the conductor circuit 25 formed on the substrate 21 is applied to the etching solution. The contained tetrazole compound is chemically adsorbed (see FIG. 1A). Thereafter, the unadsorbed portion of the tetrazole compound is mainly etched by hydrogen peroxide and sulfuric acid, and the adsorbed portion of the tetrazole compound is hardly etched (FIG. 1).
(B)). As a result, a roughened surface 25a is formed on the entire surface of the conductor circuit 25 (see FIG. 1C).

In general, it is considered that the adsorption between an azole compound such as tetrazole and copper and copper is a chemical adsorption in which a lawn pair electron of a nitrogen atom in the azole compound coordinates to copper. Further, the tetrazole compound used in the etching solution of the present invention has a tetrazole skeleton containing four nitrogen atoms. From these facts, it is considered that the tetrazole compound is extremely easily adsorbed on copper among the azoles. Therefore, a tetrazole compound can be normally adsorbed to the bottom side surface of the conductor circuit where azole or the like is not easily adsorbed.

Therefore, in the etching solution of the present invention, FIG.
As shown in (4), since the tetrazole compound contained in the etching solution is also adsorbed on the bottom side surface of the conductor circuit 25, it is considered that the conductor circuit may not be undercut by the roughened surface forming process.

As the tetrazole derivative contained in the etching solution of the present invention, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms,
20 alkylphenyl groups, amino groups, phenyl groups, mercapto groups, alkylmercapto groups having 1 to 10 carbon atoms,
Alternatively, a tetrazole derivative having a carboxyalkyl group having 1 to 10 carbon atoms can be used.

Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group and a heptyl group. , Octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradisyl group, pentadecyl group,
Examples include a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group and an icosyl group.

Examples of the tetrazole derivative having an alkyl group having 1 to 20 carbon atoms include, for example, 1-methyl-tetrazole, 5-methyl-tetrazole, 1-ethyl-
Tetrazole, 5-ethyl-tetrazole, 1-propyl-tetrazole, 5-propyl-tetrazole, 5-
Butyl-tetrazole and the like.

The cycloalkyl group having 3 to 10 carbon atoms includes, for example, cyclopropyl group, cyclobutyl group,
Examples thereof include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group.

Examples of the tetrazole derivative having a cycloalkyl group having 3 to 10 carbon atoms include 1-cyclopropyl-tetrazole, 5-cyclopropyl-tetrazole, 1-cyclohexyl-tetrazole, 5-cyclohexyl-tetrazole and the like. Can be

Examples of the alkylphenyl group having 7 to 20 carbon atoms include methylphenyl, ethylphenyl, propylphenyl, isopropylphenyl, butylphenyl, sec-butylphenyl, tert
-Butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group,
Nonylphenyl group, decylphenyl group, undecyl group,
A dodecylphenyl group, a tridecylphenyl group, a tetradecylphenyl group, and the like.

Examples of the tetrazole derivative having an alkylphenyl group having 7 to 20 carbon atoms include, for example, 1-
(3-methylphenyl) -tetrazole, 5- (3-methylphenyl) -tetrazole, 1- (3-ethylphenyl) -tetrazole, 5- (3-ethylphenyl)-
Tetrazole and the like.

Examples of the tetrazole derivative having an amino group include 5-aminotetrazole, 1-methyl-5-aminotetrazole, α-benzyl-5-aminotetrazole, β-benzyl-5-aminotetrazole and the like. .

Examples of the tetrazole derivative having a phenyl group include 1-phenyl-1H-tetrazole and 5-phenyl-2H-tetrazole.

Examples of the tetrazole derivative having a mercapto group include 1-mercapto-tetrazole and 5-mercapto-tetrazole.

The alkyl mercapto group having 1 to 10 carbon atoms includes, for example, methyl mercapto group, ethyl mercapto group, propyl mercapto group, isopropyl mercapto group, butyl mercapto group, sec-butyl mercapto group, tert-butyl mercapto group, Examples include a pentyl mercapto group, a hexyl mercapto group, a heptyl mercapto group, an octyl mercapto group, a nonyl mercapto group, and a decyl mercapto group.

Examples of the tetrazole derivative having an alkylmercapto group of 1 to 10 include 1-methylmercapto-tetrazole, 5-methylmercapto-tetrazole, 1-ethylmercapto-tetrazole,
-Ethylmercapto-tetrazole, 1-propylmercapto-tetrazole, 5-propylmercapto-tetrazole, 5-butylmercapto-tetrazole and the like.

Examples of the carboxyalkyl group having 1 to 10 carbon atoms include carboxymethyl, carboxyethyl, carboxypropyl, carboxyisopropyl, carboxybutyl, carboxypentyl,
Examples include a carboxyhexyl group, a carboxyheptyl group, a carboxyoctyl group, a carboxynonyl group, and the like.

Examples of the tetrazole derivatives having 1 to 10 carboxyalkyl groups include 1-carboxymethyl-tetrazole, 5-carboxymethyl-tetrazole, 1-carboxyethyl-tetrazole,
-Carboxyethyl-tetrazole, 1-carboxypropyl-tetrazole, 5-carboxypropyl-tetrazole, 1-carboxybutyl-tetrazole, 5-
Carboxybutyl-tetrazole and the like.

Among these tetrazole derivatives,
A tetrazole derivative having an amino group and a tetrazole derivative having a phenyl group are more preferable.

The concentration of hydrogen peroxide contained in the etching solution of the present invention is desirably 1 to 50 g / l. The concentration of the hydrogen peroxide is less than 1 g / l or 50 g / l
If it exceeds, it may not be possible to etch too deeply. More preferably, it is 5 to 40 g / l.

The concentration of sulfuric acid contained in the etching solution is desirably 1 to 50 g / l. If the concentration of the sulfuric acid is less than 1 g / l or more than 50 g / l, it may not be possible to etch too deeply. More preferably, it is 5 to 40 g / l.

The concentration of tetrazole and / or its derivative contained in the above-mentioned etching solution is set to 0.1.
1-30 g / l is desirable. The above tetrazole and / or
Alternatively, if the concentration of the derivative is less than 0.1 g / l, a roughened surface having sufficient unevenness may not be formed, and if it exceeds 30 g / l, the tetrazole compound is adsorbed on the entire surface of the conductor circuit. In some cases, a roughened surface having sufficient unevenness cannot be formed. More preferably, it is 1 to 20 g / l.

The etching solution of the present invention contains, in addition to the above-mentioned components, alcohol, an etching solution decomposer, a stabilizer,
It may contain finishing agents, brighteners and the like. The alcohol is not particularly limited and includes, for example, methanol, ethanol, butanol, propanol, pentanol,
Hexanol and the like. Of these, propanol, pentanol, and hexanol are desirable because they are less likely to volatilize. The concentration of the alcohol contained in the etching solution of the present invention is not particularly limited,
20 ml / l is desirable.

The etching solution of the present invention having the above-mentioned structure can be used for producing a multilayer printed wiring board without forming an undercut shape on the conductor circuit and forming unevenness of uniform roughness on the entire surface of the conductor circuit. Having a roughened surface. When the above-mentioned etching solution is used, a conductor circuit having a roughened surface can be formed at the same time as removing the thin-film conductor layer in a later-described manufacturing process of a multilayer printed wiring board.

Next, a brief description will be given of a process of manufacturing a multilayer printed wiring board using the etching solution of the present invention. (1) First, a substrate having a conductive circuit formed on the surface of an insulating substrate is manufactured. As the insulating substrate, a resin substrate such as a glass epoxy substrate, a bismaleimide-triazine resin substrate, and a copper-clad laminate is desirable. At this time, a through hole may be provided in the insulating substrate. In this case, the through hole has a diameter of 1
It is desirable to form it using a drill of 100 to 300 μm, a laser beam or the like.

Next, a conductor circuit is formed on the substrate.
That is, a thin-film conductor layer is formed on a substrate by electroless plating or the like, a plating resist is formed on a part of the thin-film conductor layer, and an electroplating layer is formed on a portion where no plating resist is formed. Subsequently, the plating resist is peeled off, and then, a thin film existing under the plating resist using an aqueous solution of a sulfuric acid / hydrogen peroxide aqueous solution, an aqueous solution of a persulfate such as ferric chloride, cupric chloride, or ammonium persulfate, or the like. A conductor circuit is formed by removing the conductor layer.

As the above electroless plating and electroplating,
Copper plating is preferred. This is because the etching solution of the present invention is suitable for use. Also, when a through hole is provided in the insulating substrate, when forming the thin film conductor layer,
By simultaneously applying electroless plating to the wall surfaces of the through holes to form through holes, the conductor circuits on both surfaces of the substrate may be electrically connected.

After a solid conductor layer is formed by using a copper-clad substrate or by performing electroless plating on the substrate, an etching resist having a conductor circuit shape is formed on the substrate, and the conductor circuit is etched. May be formed.

(2) Next, a roughened surface is formed on the surface of the conductor circuit. In this step, the etching solution of the present invention can be used. Specifically, a roughened surface is formed by immersing the substrate on which the conductive circuit is formed in the etching solution or spraying the substrate with the etching solution.

The average depth of the irregularities on the roughened surface is 0.1 to
10 μm is desirable. If the average depth is less than 0.1 μm, the adhesion between the conductor circuit and the resin insulating layer is low, and the resin insulating layer may be peeled off.
If the thickness exceeds 0 μm, the conductor circuit becomes too thin, the unevenness of the roughened surface is canceled out, or when an opening is formed by a laser in the resin insulating layer formed on the conductor circuit, the resin is formed on the roughened surface. The residue may be generated, and the adhesion between the conductor circuit and the resin insulating layer and the electrical characteristics may be reduced.

More preferably, it is 0.5 to 5 μm.
If the average height of the irregularities on the roughened surface is within this range, sufficient adhesion between the conductor circuit and the resin insulation layer can be obtained, and the resin insulation layer formed on the conductor circuit is irradiated with a laser. Even when the openings are formed, no resin residue is generated on the roughened surface. Further, by using the etching solution of the present invention when removing the thin film conductor layer in the step (1), the removal of the thin film conductor layer and the formation of the roughened surface can be performed simultaneously.

(3) Next, an interlayer resin insulating layer is formed on the substrate on which the conductor circuit having the roughened surface is formed. Examples of the material of the interlayer resin insulating layer include a resin composition for forming a roughened surface, a polyphenylene ether resin, a polyolefin resin, a fluororesin, and a thermoplastic elastomer. The interlayer resin insulating layer may be formed by applying an uncured resin, or may be formed by thermocompression bonding an uncured resin film. Further, a resin film in which a metal layer such as a copper foil is formed on one surface of an uncured resin film may be attached.

As the resin composition for forming a roughened surface, for example, particles that are soluble in an acid or an oxidizing agent (hereinafter referred to as “soluble particles”) are hardly soluble in an acid or an oxidizing agent (hereinafter referred to as a hardly soluble resin). And those dispersed therein. Note that the terms "sparingly soluble" and "soluble" are referred to as "soluble" for convenience when a substance having a relatively high dissolution rate is immersed in the same roughening solution for the same time, and the relative dissolution rate is relatively low. The slower one is called "poorly soluble" for convenience. Examples of the soluble particles include resin particles soluble in an acid or an oxidizing agent, inorganic particles soluble in an acid or an oxidizing agent, and metal particles soluble in an acid or an oxidizing agent. These may be used alone or in combination of two or more.

The hardly soluble resin is not particularly limited as long as it can maintain the shape of the roughened surface when the roughened surface is formed using an acid or an oxidizing agent in the interlayer resin insulating layer. Examples thereof include a thermosetting resin, a thermoplastic resin, and a composite thereof. As the thermosetting resin,
For example, an epoxy resin, a phenol resin, a polyimide resin, and the like can be given. Further, as the thermoplastic resin,
For example, phenoxy resin, polyether sulfone (P
ES), polysulfone (PSF), polyphenylene sulfone (PPS), polyphenylene sulfide (P
PES), polyphenylene ether (PPE), polyetherimide (PI), fluororesin, and the like.

The polyphenylene ether resin is not particularly limited, and examples thereof include PPO and PPE. As the polyolefin resin, for example, polyethylene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, cycloolefin resin,
Copolymers of these resins and the like can be mentioned. Among them, cyclo-dielectric materials have low dielectric constant and dielectric loss tangent, are unlikely to cause signal delay and signal error even when a high-frequency signal in the GHz band is used, and are excellent in mechanical characteristics such as rigidity. Olefin resins are desirable.

Examples of the fluororesin include ethyl / tetrafluoroethylene copolymer resin (ETFE), polychlorotrifluoroethylene (PCTFE) and the like. The thermoplastic elastomer resin is not particularly limited, for example, a styrene-based thermoplastic elastomer,
Examples include olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, 1,2-polybutadiene-based thermoplastic elastomers, PVC-based thermoplastic elastomers, and fluorine-based thermoplastic elastomers. Among these, olefin-based thermoplastic elastomers and fluorine-based thermoplastic elastomers are desirable from the viewpoint of excellent electrical properties.

When the interlayer resin insulating layer is formed by attaching the above resin film, the interlayer resin insulating layer is formed using a device such as a vacuum laminator under reduced pressure or vacuum under a pressure of 2.0 to 10 kgf / kg. pressure of cm ^2,
It is desirable to perform pressure bonding at a temperature of 60 to 120 ° C., and then heat-curing the resin film. The heat curing may be performed after forming a via hole opening and a through hole described later.

(4) Next, a via hole opening and, if necessary, a through hole are formed in the substrate on which the interlayer resin insulating layer is formed. The via hole opening is formed by laser processing or the like. When an interlayer resin insulating layer made of a photosensitive resin is formed, by performing exposure and development processing,
A via hole opening may be provided. The laser light used at this time includes, for example, a carbon dioxide gas (CO ₂ ) laser, an ultraviolet laser, an excimer laser, etc. Among them, an excimer laser or a short-pulse carbon dioxide laser is desirable.

(5) Next, the surface of the interlayer resin insulation layer including the inner wall of the opening for the via hole and the inner wall of the through hole when the through hole is formed in the above step are roughened with an acid or an oxidizing agent. To form a surface. Examples of the acid include sulfuric acid, nitric acid, hydrochloric acid,
Examples of the oxidizing agent include phosphoric acid, formic acid, and the like. Examples of the oxidizing agent include permanganates such as chromic acid, chromic sulfuric acid, and sodium permanganate.

(6) Next, a catalyst is applied to the formed roughened surface, if necessary. Examples of the catalyst include palladium chloride. (7) Then, a thin film conductor layer is formed on the formed interlayer resin insulating layer by using electroless plating or the like. In addition, the above (4)
When the through hole is formed in the step, the 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.

(8) Next, a plating resist is formed on a part of the thin film conductor layer using a dry film, and thereafter,
Electroplating is performed using the thin-film conductor layer as a plating lead, and an electroplating layer is formed on the portion where the plating resist is not formed.

(9) Next, the plating resist is peeled off,
The thin film conductor layer existing under the plating resist was
An aqueous solution of hydrogen peroxide, ferric chloride, cupric chloride, removed using an aqueous solution of a persulfate such as ammonium persulfate or the like, and then the surface of the electroplating layer and the thin film conductor using an etching solution of the present invention. A roughened surface is formed on the side surface of the layer, and an independent conductor circuit having a roughened surface is formed. When removing the thin film conductor layer, by using the etching solution of the present invention, while removing the thin film conductor layer,
A roughened surface may be formed on the surface of the electroplating layer and the side surface of the thin film conductor layer.

(10) Thereafter, if necessary, the steps (3) to (9) are repeated to form a conductor circuit having a roughened surface.

(11) Next, a solder resist layer is formed on the substrate surface including the uppermost conductive circuit. As the solder resist layer, for example, polyphenylene ether resin,
Examples thereof include those composed of a polyolefin resin, a fluororesin, a thermoplastic elastomer, a solder resist resin composition, and the like.

(12) Next, a corrosion-resistant metal layer made of Ni, Au, or the like is formed on the opening of the solder resist layer by plating, sputtering, or vapor deposition, and then, a solder paste is printed on the IC chip connection surface. Thus, solder bumps are formed, and solder balls, pins, and the like are provided on the external substrate connection surface, thereby completing the manufacture of the printed wiring board.

[0066]

The present invention will be described in more detail below. Example 1 A. Preparation of Resin Film for Interlayer Resin Insulation Layer Bisphenol A type epoxy resin (Epoxy equivalent 46
9. Yuka Shell Epoxy Co., Epicoat 1001) 3
0 parts by weight, 40 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 215, Epichron N-673 manufactured by Dainippon Ink and Chemicals, Inc.), a triazine structure-containing phenol novolak resin (phenolic hydroxyl group equivalent: 120,
FENOLITE KA-705 manufactured by Dainippon Ink and Chemicals, Inc.
2) 30 parts by weight were dissolved by heating in 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha while stirring, and epoxidized polybutadiene rubber (Denalex R-45EPT manufactured by Nagase Kasei Kogyo Co., Ltd.) was added thereto.
15 parts by weight, 1.5 parts by weight of a crushed product of 2-phenyl-4,5-bis (hydroxymethyl) imidazole, 2 parts by weight of finely divided silica, and 0.5 part by weight of a silicon-based antifoaming agent are added to the epoxy resin composition. Was prepared. The resulting epoxy resin composition is applied on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, and then dried at 80 to 120 ° C. for 10 minutes to form an interlayer resin. A resin film for an insulating layer was produced.

B. Preparation of resin filler 1) 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., molecular weight: 310, YL983U), the average particle size of which surface is coated with a silane coupling agent is 1.6 μm, and the largest particle Having a diameter of 15 μm or less
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 9 Pa · s resin filler was prepared. In addition, as a curing agent, an imidazole curing agent (2E4MZ- manufactured by Shikoku Chemicals Co., Ltd.)
6.5 parts by weight (CN).

C. Manufacturing method of printed wiring board (1) 1 mm thick glass epoxy resin or BT (bismaleimide triazine) resin
A copper-clad laminate on which an 8 μm copper foil 8 was laminated was used as a starting material (see FIG. 3A). First, the copper-clad laminate was drilled, subjected to an electroless plating treatment, and etched in a pattern to form a lower conductor circuit 4 and a through hole 9 on both surfaces of the substrate 1.

(2) Through-hole 9 and lower conductor circuit 4
After the substrate on which is formed is washed with water and dried, hydrogen peroxide 2
0 g / l, sulfuric acid 15 g / l, 5-aminotetrazole 3
An etching solution containing g / l and 10 ml / l of propyl alcohol is sprayed onto both surfaces of the substrate by spraying, and is sent by a transport roll to etch the surface of the lower conductive circuit 4 and the land surface and inner wall of the through hole 9. Thereby, roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 3B).

(3) After preparing the resin filler described in B above, within 24 hours after the 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 conductive circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed in the conductive circuit non-forming portion having a concave portion using a squeegee. It was dried at 20 ° C. for 20 minutes (see FIG. 3C).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sander polishing using # 600 belt polishing 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, a 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 layer of the resin filler 10 and the surface of the lower conductor circuit 4 formed in the through holes 9 and the portions where the conductor circuit is not formed 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 firmly adhered through the roughened surface to obtain an insulating substrate (see FIG. 3D). That is, by this step, the surface of the resin filler 10 and the surface of the lower conductive circuit 4 become flush with each other.

(5) The above substrate was washed with water and acid-degreased, and then soft-etched. Then, 20 g / l of hydrogen peroxide, 15 g / l of sulfuric acid, 3 g / l of 5-aminotetrazole and 10 ml / l of propyl alcohol were added. The sprayed etchant is sprayed on both sides of the substrate by a spray, and is sent by a transport roll.
By etching the land surface and the inner wall of the lower conductor circuit 4, rough surfaces 4a and 9a (roughening depth 3
μm) (see FIG. 4A).

(6) An interlayer resin insulating layer was formed on both surfaces of the substrate by bonding the resin film for the interlayer resin insulating layer prepared in A above by using a vacuum laminator apparatus by the following method (FIG. 4 ( b)). That is, a resin film for an interlayer resin insulation layer is placed on a substrate, the degree of vacuum is 0.5 Torr, the pressure is 4 kgf / cm ² , the temperature is 80 ° C.,
Pasting was performed under the condition of a pressure bonding time of 60 seconds, and thereafter, thermosetting was performed at 100 ° C. for 30 minutes and at 150 ° C. for 1 hour.

(7) Next, CO2 having a wavelength of 10.4 μm is formed on the interlayer resin insulating layer 2 through a mask in which a through hole is formed.
₂ Gas laser, beam diameter 4.0 mm, top hat mode, pulse width 8.0 μsec, diameter of through hole of mask 1.
Via holes 6 having a diameter of 60 μm were formed in the interlayer resin insulating layer 2 under the conditions of 0 mm and one shot.
(C)).

(8) The substrate on which the via hole opening 6 is formed is placed in a 70 ° C. solution containing 800 g / l of chromic acid.
The surface of the interlayer resin insulating layer 2 including the inner wall of the via hole opening 6 was roughened by immersing for a minute to dissolve and remove the epoxy resin particles present on the surface of the interlayer resin insulating layer 2 (FIG. 4 ( d)).

(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 (manufactured by Atotech) to the surface of the substrate subjected to the surface roughening treatment (roughening depth: 6 μm), the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6 are formed. Catalyst nuclei were deposited.

(10) Next, the substrate is immersed in an electroless copper plating aqueous solution having the following composition, and has a thickness of 0.6 to 0.
An electroless copper plating layer 12 of 9 μm was formed (FIG. 5A).
reference). [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 layer 12, a mask is placed thereon, and
Exposure at mJ / cm ² and development processing with a 0.8% aqueous solution of sodium carbonate provided a plating resist 3 having a thickness of 25 μm (see FIG. 5B).

(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. The layer 13 was formed (see FIG. 5C). [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) Next, the plating resist 3 is made of 5% KOH
Then, the electroless plating layer 12 under the plating resist 3 is treated with an etching solution made of ferric chloride to be dissolved and removed, whereby the thickness of the electroless copper plating film and the electrolytic copper plating film is reduced. A conductor circuit (including the via hole 7) 5 having a thickness of 18 μm was formed (see FIG. 5D). Further, a roughened surface (roughened depth of 3 μm) was formed on the surface of the conductor circuit using an etching solution similar to the etching solution used in (5) above.
Was formed (see FIG. 6A).

(14) By repeating the above steps (5) to (13), a conductor circuit of a further upper layer was formed, and a multilayer wiring board was obtained (see FIGS. 6B to 7B). .

(15) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight was used. 46.67 parts by weight of an oligomer for imparting properties (molecular weight: 4000), 15.0 parts by weight of 80% by weight of a bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Epoxy Co.) dissolved in methyl ethyl ketone, imidazole 1.6 parts by weight of a curing agent, 3 parts by weight of a polyacrylic monomer (R604, manufactured by Nippon Kayaku Co., Ltd.) which is a photosensitive monomer, and polyacrylic monomer (manufactured by Kyoeisha Chemical Co., Ltd.)
DPE6A) 1.5 parts by weight and 0.71 part by weight of a dispersion defoaming agent (manufactured by San Nopco, S-65) are placed in a container and stirred.
A mixed composition was prepared by mixing, and 2 parts by weight of benzophenone (manufactured by Kanto Kagaku) as a photopolymerization initiator and 0.2 parts by weight of Michler's ketone (manufactured by Kanto Kagaku) as a photosensitizer were added to the mixed composition. By adding parts, the viscosity is 25
A solder resist composition adjusted to 1.4 ± 0.3 Pa · s at ℃ 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 ppm. In the case of 4, 6 rpm, the rotor No. According to 3.

(16) Next, the above-mentioned solder resist composition is applied to both sides of the multilayer wiring board in a thickness of 20 μm,
After performing a drying process under the conditions of 20 ° C. for 20 minutes and 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the opening of the solder resist is drawn is brought into close contact with the solder resist layer, and an ultraviolet ray of 1000 mJ / cm ² is applied. Exposure, DM
Development was performed with a TG solution to form an opening having a diameter of 200 μm. Then, the solder resist layer is further heated 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 to cure the solder resist layer.
The solder resist layer 14 having an opening and having a thickness of 20 μm was formed. Further, instead of the above-mentioned solder resist composition, a commercially available solder resist composition or LPS
R, a solder resist layer may be formed by forming an opening by laser processing using a solder resist composition or the like formed into a film.

(17) Next, the substrate on which the solder resist layer 14 has been formed is coated with nickel chloride (2.3 × 10 ^-1 mol / 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 plating solution containing sodium hypophosphite (1.7 × 10 ⁻¹ mol / l) at 80 ° C. for 7.5 minutes to form a layer having a thickness of 0 A gold plating layer 16 having a thickness of 0.03 μm was formed.

(18) Thereafter, 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.
A multilayer printed wiring board having the solder bumps 17 was manufactured (see FIG. 7C).

(Embodiment 2) In the step (13) of the embodiment 1, after the plating resist 3 was peeled off with 5% KOH,
Hydrogen peroxide 30 g / l, sulfuric acid 15 g / l, 5-aminotetrazole 4 g / l, propyl alcohol 15 ml / l
The electroless plating layer 12 under the plating resist 3 is removed by using an etching solution composed of: and a roughened surface (roughened depth 3) is formed on the surface of the electrolytic copper plating film and the side surface of the electroless copper plating film.
Example 1 except that a conductor circuit (including a via hole 7) 5 having a thickness of 18 μm, comprising an electroless copper plating film and an electrolytic copper plating film, and having a roughened surface was formed. A multilayer printed wiring board was manufactured in the same manner as described above.

Embodiment 3 A. Production of Printed Wiring Board (1) A copper clad laminate in which 18 μm copper foil 8 is laminated on both sides of a substrate 1 made of glass epoxy resin or BT (bismaleimide-triazine) resin having a thickness of 1 mm was used as a starting material. (See FIG. 8A). First, this copper-clad laminate is drilled, and then a plating resist is formed. Then, the substrate is subjected to an electroless copper plating treatment to form through holes 9, and the copper foil is patterned in a conventional manner. Then, an inner copper pattern (lower conductive circuit) 4 was formed on both surfaces of the substrate.

(2) The substrate on which the lower conductor circuit 4 is formed is washed with water and dried, and then hydrogen peroxide 20 g / l and sulfuric acid 20 g
/ L, 5 g / l of 5-phenyltetrazole and 10 ml / l of propyl alcohol are sprayed onto both surfaces of the substrate by spraying, and are sent by a transport roll to send the surface of the lower conductor circuit 4 and the land of the through hole 9. By etching the surface and the inner wall, roughened surfaces 4a and 9a were formed on the entire surface of lower conductive circuit 4 (FIG. 8).
(B)).

(3) After preparing the resin filler described in the above A, within 24 hours after the preparation by the following method, the conductor circuit non-formed portion and the conductor 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 conductive circuit non-forming portion is placed on the substrate, and a layer of the resin filler 10 is formed in the conductive circuit non-forming portion having a concave portion using a squeegee. It was dried at 20 ° C. for 20 minutes (see FIG. 8C).

(4) One surface of the substrate after the treatment of (3) above is subjected to belt sanding using a belt abrasive paper (manufactured by Sankyo Rikagaku Co., Ltd.) to form a surface of the lower conductive circuit 4 and a land surface of the through hole 9. Was polished so that the resin filler 10 did not remain, and then buffed to remove the scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, the filled resin filler 10 was cured by heating (see FIG. 8D).

In this manner, the surface layer of the resin filler 10 filled in the through holes 9 and the like and the roughened layer 4a on the upper surface of the lower conductor circuit 4 are removed to smooth both surfaces of the substrate, and the resin filler 10 and the lower layer are removed. A wiring board was obtained in which the side surfaces of the conductive circuit 4 were firmly adhered through the roughened surface 4a, and the inner wall surface of the through hole 9 was tightly adhered to the resin filler 10 through the roughened surface 9a.

(5) Next, the same etching solution as the etching solution used in (2) is sprayed on both surfaces of the substrate after the treatment in (4), and is sent by a transport roll to once. By etching the flattened surface of the lower conductor circuit 4 and the land surface of the through hole 9, the entire surface of the lower conductor circuit 4 has roughened surfaces 4a and 9a (roughened depth 3).
μm) (see FIG. 9A).

(6) Next, on both surfaces of the substrate having undergone the above steps,
A pressure of 5 kg / c while heating a thermosetting type cycloolefin resin sheet having a thickness of 50 μm to a temperature of 50 to 150 ° C.
Vacuum compression lamination was performed at m ² to provide an interlayer resin insulating layer 2 made of a cycloolefin-based resin (see FIG. 9B). The degree of vacuum during vacuum compression was 10 mmHg.

(7) Next, a laser beam is irradiated on the interlayer resin insulating layer 2 by using an excimer laser having a wavelength of 248 nm through a mask in which a through hole is formed, thereby forming a cycloolefin resin. Diameter 8 for interlayer resin insulation layer 2
A 0 μm via hole opening 6 was provided (see FIG. 9C). Thereafter, a desmear treatment was performed using oxygen plasma.

(8) Next, SV manufactured by Japan Vacuum Engineering Co., Ltd.
Using −4540, sputtering with Ni as the target was performed at a gas pressure of 0.6 Pa, a temperature of 80 ° C., and a power of 200.
This was performed under the conditions of W for 5 minutes, and a Ni metal layer 12a was formed on the surface of the interlayer resin insulating layer 2 (see FIG. 9D). At this time, the thickness of the formed Ni metal layer 12a is 0.1 μm.
m. Further, on the Ni metal layer 12a, sputtering using Cu as a target was performed under the same conditions to form a Cu metal layer 12b. At this time, the thickness of the formed Cu metal layer 12b was 0.1 μm (see FIG. 10A).

(9) A commercially available photosensitive dry film is adhered to both surfaces of the substrate after the above treatment, a photomask film is placed, and after exposure at 100 mJ / cm ² ,
It was developed with 0.8% sodium carbonate to form a pattern of a plating resist 3 having a thickness of 25 μm (FIG. 10B).
reference).

(10) 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. The layer 13 was formed (see FIG. 10C). [Aqueous electrolytic plating solution] Sulfuric acid 2.24 mol / l Copper sulfate 0.26 mol / l Additive 19.5 ml / l (Acapec Japan, Capparaside GL) [Electroplating conditions] Current density 1 A / dm ² hours 65 minutes temperature 22 ± 2 degrees

(11) Next, the plating resist 3 is changed to 5% KOH
Then, the thin film conductor layer 12 under the plating resist 3 is treated with an etching solution composed of ferric chloride to dissolve and remove the thin film conductor layer 12, so that the thickness of the electroless copper plating film and the electrolytic copper plating film is reduced. A conductor circuit (including the via hole 7) 5 of 18 μm was formed (see FIG. 10D). Further, a roughened surface (roughened depth of 3 μm) is formed on the conductor circuit surface by using the same etching solution as the etching solution used in the above (2).
Was formed (see FIG. 11A).

(12) By repeating the above steps (5) to (11), a conductor circuit of a further upper layer was formed, and a multilayer wiring board was obtained (see FIGS. 11 (b) to 12 (b)). .

(13) Next, a thermosetting cycloolefin resin sheet having a thickness of 20 μm was formed on both surfaces of the multilayer wiring board on which the upper conductor circuit was formed, while increasing the temperature to 50 to 150 ° C. while applying a pressure of 5 kg / cm. Vacuum compression lamination was performed in ² to provide a solder resist layer 14 made of a cycloolefin resin. In addition, the degree of vacuum at the time of vacuum compression bonding was 10 mmHg.

(14) Next, an opening having a diameter of 200 μm was formed in the solder resist layer 14 made of a cycloolefin resin using an excimer laser having a wavelength of 248 nm. Thereafter, desmearing treatment was performed using oxygen plasma to form a solder resist layer 14 having a thickness of 20 μm and an opening in the solder pad portion.

(15) Next, the substrate on which the solder resist layer 14 is formed is coated with nickel chloride (2.3 × 10 ⁻¹ mol / 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 plating solution containing sodium hypophosphite (1.7 × 10 ⁻¹ mol / l) at 80 ° C. for 7.5 minutes to form a layer having a thickness of 0 A gold plating layer 16 having a thickness of 0.03 μm was formed.

(16) Thereafter, a solder paste is printed in the openings of the solder resist layer 14 and reflowed at 200 ° C. to form solder bumps (solder bodies) 17.
A multilayer printed wiring board having the solder bumps 17 was manufactured (see FIG. 12C).

(Embodiment 4) In the step (11) of the embodiment 1, after the plating resist 3 is peeled off with 5% KOH,
Hydrogen peroxide 25 g / l, sulfuric acid 10 g / l, 5-aminotetrazole 5 g / l, and propyl alcohol 7 m
plating resist 3 using an etching solution containing 1 / l
The lower electroless plating layer 12 is removed, and a roughened surface (roughening depth: 3 μm) is formed on the surface of the electrolytic copper plating film and the side surface of the electroless copper plating film, and the electroless copper plating film and the electrolytic copper plating film are formed. Except that a conductor circuit (including a via hole 7) 5 having a roughened surface on the surface and having a thickness of 18 μm was formed.
A multilayer printed wiring board was manufactured in the same manner as in Example 3.

Comparative Example 1 In Example 1, 20 g / l of hydrogen peroxide, 15 g / l of sulfuric acid, 3 g / l of 5-aminotetrazole, and 10 ml / l of propyl alcohol
A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that an etching solution containing a cupric complex and an organic acid salt was used instead of the etching solution containing. The etching solution containing the cupric complex and the organic acid salt is composed of 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.

Comparative Example 2 In Example 2, 30 g / l of hydrogen peroxide, 15 g / l of sulfuric acid, 4 g / l of 5-aminotetrazole, and 15 ml / l of propyl alcohol
A multilayer printed wiring board was manufactured in the same manner as in Example 2 except that the same etching solution containing a cupric complex and an organic acid salt as used in Comparative Example 1 was used instead of the etching solution containing Comparative Example 1. did.

Comparative Example 3 In Example 3, 20 g / l of hydrogen peroxide, 20 g / l of sulfuric acid, 5 g / l of 5-phenyltetrazole and 10 ml / l of propyl alcohol
A multilayer printed wiring board was prepared in the same manner as in Example 3 except that the same etching solution containing a cupric complex and an organic acid salt as used in Comparative Example 1 was used instead of the etching solution containing l. Manufactured.

Comparative Example 4 Comparative Example 4 was repeated, except that the etching solution contained 25 g / l of hydrogen peroxide, 10 g / l of sulfuric acid, 5 g / l of 5-aminotetrazole, and 7 ml / l of propyl alcohol. A multilayer printed wiring board was manufactured in the same manner as in Example 4 except that the same etching solution containing a cupric complex and an organic acid salt as used in Example 1 was used.

(Comparative Example 5) In Example 1, instead of forming a roughened surface on a conductor circuit surface using an etching solution, Cu-Ni-P plating was performed to form a Cu-Ni-P plating film on the conductor circuit surface under the following conditions. A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that a roughened layer made of a Ni-P alloy was formed.

When forming the roughened layer, first, the substrate is alkali-degreased and soft-etched, and then treated with a catalyst solution comprising palladium chloride and an organic acid to provide a Pd catalyst. Was activated. Next, copper sulfate (3.2 × 10 ⁻² mol / l), nickel sulfate (2.4 × 10 ⁻³ mol / l) and citric acid (5.2 × 1
0 ^-2 mol / l), sodium hypophosphite (2.7 × 1
0 ^-1 mol / l), boric acid (5.0 × 10 ^-1 mol / l)
l), pH = 9 consisting of an aqueous solution of a surfactant (Sufinol 465, manufactured by Nissin Chemical Industry Co., Ltd.) (1.0 g / l).
In the electroless plating bath of No. 1, electroless plating was performed to form a roughened layer made of a Cu—Ni—P alloy on the entire surface of the conductor circuit.

(Comparative Example 6) In Example 3, a Cu-Ni-P plating treatment was performed under the same conditions as in Comparative Example 5 instead of forming a roughened surface on the conductor circuit surface using an etching solution. A multilayer printed wiring board was manufactured in the same manner as in Example 3, except that a roughened layer made of a Cu-Ni-P alloy was formed on the surface of the conductor circuit.

With respect to the multilayer printed wiring boards of Examples 1 to 4 and Comparative Examples 1 to 6 manufactured as described above, the peel strength (kg / c) between the conductor circuit and the interlayer resin insulating layer was obtained.
m), presence or absence of undercut of the conductor circuit, presence or absence of resin residue on the surface of the conductor circuit, and presence or absence of peeling between the conductor circuit and the interlayer resin insulation layer before and after the reliability test;
The presence or absence of peeling between the upper and lower conductor circuits in the via hole and the occurrence of short circuit and disconnection during the continuity test were evaluated using the following evaluation methods. The results are shown in Table 1.

[0114]Evaluation method  (1) Peel strength Adhesion to interlayer resin insulation layer using a commercially available peel strength measuring instrument
And measured.

(2) Presence / absence of undercut and presence / absence of resin residue The multilayer printed wiring board was cut with a cutter, and the cut section was observed with a microscope.

(3) Reliability Test A cycle of maintaining the obtained multilayer printed wiring board in an atmosphere of -65 ° C for 3 minutes and then in an atmosphere of 130 ° C for 3 minutes was repeated 1,000 times.

(4) Peeling between the conductor circuit and the interlayer resin insulation layer and peeling between the upper and lower conductor circuits In the same manner as in (2), the multilayer printed wiring board was cut with a cutter, and the cut cross section was cut. Was observed under a microscope.

(5) Presence or Absence of Short-Circuit or Disconnection An IC chip was connected to the obtained multilayer printed wiring board, a continuity test was performed on the IC chip, and a continuity state was evaluated from the result displayed on the monitor.

[0119]

[Table 1]

As a result, as shown in Table 1, Example 1
In the multilayer printed wiring boards manufactured in Nos. 1 to 4, the peel strength is 1.1 kg / cm or more, there is sufficient adhesion between the conductive circuit and the interlayer resin insulating layer, and the conductive circuit may have an undercut shape. No resin residue was generated on the conductor circuit surface. Also, in the multilayer printed wiring board,
Before and after the reliability test, no peeling occurred between the conductor circuit and the interlayer resin insulating layer or the upper layer conductor circuit, and no short circuit or disconnection was observed in the conduction test.

On the other hand, in the multilayer printed wiring boards of Comparative Examples 1 to 4, the peel strength was 1.0 kg / cm,
Although the adhesion between the conductor circuit and the interlayer resin insulation layer was not significantly inferior to that of the multilayer printed wiring boards of Examples 1 to 4, the variation in peel strength depending on the measurement site was large, and 0.8 kg / cm or less. Also, some of the conductor circuits had an undercut shape. In addition, resin residue was observed on the upper surfaces of some of the conductor circuits, and in the continuity test, disconnection was observed in some of the upper and lower conductor circuits. Furthermore, in the multilayer printed wiring boards of Comparative Examples 2 and 4, a short circuit was also found in a part between adjacent conductor circuits. Further, in the multilayer printed wiring board, after the reliability test, there was a portion where the peeling occurred between the conductive circuit and the interlayer resin insulating layer or the upper conductive circuit.

Further, in the multilayer printed wiring boards of Comparative Examples 5 and 6, the peel strength was 1.0 kg / cm, and
The adhesion between the conductor circuit and the interlayer resin insulation layer is not significantly inferior to that of the multilayer printed wiring boards of Nos. 4 to 4, and although there is no undercut-shaped conductor circuit, the upper surface of some of the conductor circuits is Resin residue was observed, and in the continuity test, disconnection was observed in part between the upper and lower conductor circuits. In addition, a short circuit was observed in a part between adjacent conductor circuits. Further, due to the resin residue on the upper surface of the conductor circuit, there was a portion where peeling occurred between the conductor circuit and the interlayer resin insulating layer or the upper conductor circuit after the reliability test.

[0123]

As described above, the etching solution of the present invention can be used for producing a multilayer printed wiring board without forming an undercut shape on the conductor circuit and having a uniform roughness on the entire surface of the conductor circuit. A roughened surface having irregularities can be formed.

[Brief description of the drawings]

FIGS. 1A to 1C are cross-sectional views schematically showing steps of forming a roughened surface on a conductor circuit surface using an etching solution of the present invention.

FIG. 2 is a partially enlarged sectional view of A in FIG. 1 (a).

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 4D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

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

FIGS. 6A to 6C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 7A to 7C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 8A to 8D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 9A to 9D are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 10A to 10D are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 11A to 11C are cross-sectional views illustrating a part of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIGS. 12A to 12C are cross-sectional views showing a part of the manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 13A to 13C are cross-sectional views schematically showing steps of forming a roughened surface on a conductor circuit surface using a conventional etching solution.

FIG. 14 is a partially enlarged sectional view of A in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Interlayer resin insulation layer (resin layer for forming a roughened surface) 3 Plating resist 4 Lower layer conductor circuit 4a Roughened surface 5 Conductor circuit 6 Opening for via hole 7 Via hole 8 Copper foil 9, 29 Through hole 9a Roughened surface DESCRIPTION OF SYMBOLS 10 Resin filler 12 Electroless copper plating layer 12a Ni metal layer 12b Cu metal layer 13 Electroplating layer 14 Solder resist layer 15 Nickel plating layer 16 Gold plating layer 17 Solder bump 22 Resin insulation layer 23 Plating resist 24 Thin film conductor layer 24b Rough Roughened surface 21, 31 Substrate 25, 35 Electroplated layer 25a, 35a Roughened surface 35b Undercut

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K057 WA05 WA07 WB04 WB17 WE03 WE25 WE30 WG03 WN01 5E339 AC01 AE01 BC02 BD03 BD06 BD08 BD11 BE13 BE15 CD05 CE12 CE14 CE17 5E343 AA07 AA17 AA33 BB24 BB44 CC50 DD43 DD76 EE33 EE52 ER18 GG06 5E346 AA12 AA15 AA32 CC32 CC58 EE31 EE38 GG22 GG27 GG28 HH11

Claims (3)

[Claims] 1. A method for manufacturing a multilayer printed wiring board in which a conductive circuit and a resin insulating layer are sequentially formed on a substrate, wherein the multilayer printed wiring board contains hydrogen peroxide, sulfuric acid, tetrazole and / or a derivative thereof. Etchant. 2. The tetrazole derivative has 1 carbon atom.
An alkyl group having from 20 to 20 carbon atoms, a cycloalkyl group having from 3 to 10 carbon atoms, an alkylphenyl group having from 7 to 20 carbon atoms, an amino group,
The etching solution according to claim 1, wherein the etching solution has a phenyl group, a mercapto group, an alkylmercapto group having 1 to 10 carbon atoms, or a carboxyalkyl group having 1 to 10 carbon atoms. 3. The concentration of the hydrogen peroxide is 1 to 50 g / l.
Wherein the concentration of the sulfuric acid is 1 to 50 g / l, and the concentration of the tetrazole and / or its derivative is
3. The etching solution according to claim 1, wherein the amount of the etching solution is 0.1 to 30 g / l.