JP2003298203A - Printed wiring board and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board having an integrated capacitor element which is free from the environmental influence such as humidity and has a stable capacitance value, and to provide a manufacturing method thereof. <P>SOLUTION: This manufacturing method of the printed wiring board having an integrated capacitor element comprises a process (1) for pattern-forming a lower electrode on the portion where the capacitor element in an internal layer board is formed, a process (2) for forming an interlayer dielectric by curing a curable composition including an alicyclic olefin polymer and a curing agent over the lower electrode formed in the process (1), and a process (3) for forming the capacitor element by pattern-forming an upper electrode on the interlayer dielectric formed in the process (2). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor element built-in printed wiring board and a method for manufacturing the same, and more particularly to a printed wiring board excellent in electrical characteristics and high density and a method for manufacturing the same.

[0002]

2. Description of the Related Art With the recent trend toward higher density and higher speed of electronic equipment, there is an increasing demand for higher density and higher frequency of printed wiring boards. Although miniaturization of components is progressing as a means for increasing the density of printed wiring boards, the current level is close to the limit in view of mounting yield, and further miniaturization is difficult. Also, the mounting design of the printed wiring board has become very difficult due to restrictions on the layout conditions such as bypass capacitors to be mounted near the IC terminals.

Conventionally, passive electronic components such as capacitors and resistors have been connected to a printed circuit board by soldering. However, for the reasons described above, recently, a method of providing a capacitor element in an interlayer insulating layer of the printed circuit board has been proposed. (For example, JP 2001-15928 A and JP 9-116247 A).

[0004]

However, in this method, when the capacitor element is formed in the interlayer insulating layer using the conventional interlayer insulating material such as epoxy resin, the dielectric constant of the interlayer insulating layer is such as humidity. There is a problem in that the capacitor cannot be used as a capacitor that requires high accuracy because the capacitor capacity changes due to the influence of the environment.

The present invention was devised to solve such a problem, and is not affected by the environment such as humidity, and has a built-in capacitor element having a stable capacitor capacity and a printed wiring board. It is an object to provide a manufacturing method thereof.

[0006]

The present invention is, firstly, a method of manufacturing a printed wiring board having a capacitor element, in which a lower electrode is patterned on a portion of the board where the capacitor element is to be formed (1). ) And a step (2) of forming an interlayer insulating layer formed by curing a curable composition containing an alicyclic olefin polymer and a curing agent on the lower electrode formed in the step (1), Provided is a method for manufacturing a printed wiring board, which comprises a step (3) of forming a capacitor element by patterning an upper electrode on the interlayer insulating layer formed in the step (2).

In the manufacturing method of the present invention, after the step (1) of patterning the lower electrode and before the step (2) of forming the interlayer insulating layer, the interlayer insulating layer is formed on the lower electrode. After the step (1 ') of forming a capacitor insulating layer having a higher dielectric constant than the dielectric constant, and after the step (2) of forming the interlayer insulating layer, before the step (3) of forming a capacitor element. A step (2 ′) of exposing the capacitor insulating layer by polishing the surface of the interlayer insulating layer flat.
Is preferably provided. Further, after the step (1) of patterning the lower electrode, and before the step (1 ′) of forming the capacitor insulating layer, the method further includes the step of forming a dam pattern so as to surround the lower electrode. Is more preferable.

Further, in the manufacturing method of the present invention, in the step (3) of forming the capacitor element, a base film composed of two layers of nickel alloy and copper is patterned on the surface of the interlayer insulating layer and / or the capacitor insulating layer. By forming, then patterning the upper electrode while leaving the underlying film of the portion where the thin film resistor is to be formed, and further selectively etching only the copper of the underlying film where the thin film resistor is to be formed. It is preferable to include forming a thin film resistor made of a nickel alloy. The present invention is secondly
A printed wiring board manufactured by the manufacturing method of the present invention is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the printed wiring board and the method for manufacturing the same according to the present invention will be described in detail below. 1) Printed Wiring Board FIGS. 1A and 1B show a cross-sectional structure of the printed wiring board of the present invention. In the printed wiring board shown in FIG. 1A, the upper electrode 41 is provided on the lower electrode 21 formed on the core material 11 via the interlayer insulating layer 31, and the lower electrode 21 and the interlayer insulating layer 31. And a capacitor element is formed by the upper electrode 41. Also,
The lower electrode 21 is electrically connected to the lower conductor circuit layer 51, and the lower conductor circuit layer 51 is electrically connected to the upper conductor circuit layer 71 via the wiring formed in the via hole 61.

In the printed wiring board shown in FIG. 1 (a), since the interlayer insulating layer 31 is formed of a curable composition containing an alicyclic olefin polymer and a curing agent, the printed wiring board is not affected by the environment such as humidity. It has a built-in capacitor that has a stable capacitor capacity.

In the printed wiring board shown in FIG. 1B, a capacitor insulating layer 33 made of a high dielectric constant material is formed between the lower electrode 22 and the upper electrode 42. Figure 1
According to the printed wiring board shown in (b), the capacitance of the capacitor can be increased and the capacitor can be downsized.

2) Method for Manufacturing Printed Wiring Board The method for manufacturing a printed wiring board according to the present invention comprises a step (1) of patterning a lower electrode on a portion of a substrate where a capacitor element is to be formed,
A step (2) of forming an interlayer insulating layer obtained by curing a curable composition containing an alicyclic olefin polymer and a curing agent on the lower electrode formed in the step (1);
There is a step (3) of forming a capacitor element by patterning an upper electrode on the interlayer insulating layer formed in the step (2). Hereinafter, the manufacturing method of the present invention will be described in detail with reference to a printed wiring board manufacturing example shown in FIG.

(A) Step of Forming Pattern with Lower Electrode (1) First, the lower electrode 21 and the lower conductor circuit layer 51 are formed on the core material 11. The core material 11 may be any material as long as it can hold electrodes and elements, and may have a conductor circuit layer and an interlayer insulating layer (or an electrical insulating layer) inside.

A part of the lower conductor circuit layer 51 formed on the electrically insulating layer (not shown) on the surface of the core material 11 may be a metal power source layer, a metal ground layer, or a metal shield layer.

Examples of the resin constituting the electric insulating layer include epoxy resin, phenol resin, acrylic resin, polyimide resin, polyisocyanate resin, polyester resin, polyphenyl ether resin, alicyclic olefin resin, bismaleimide triazine resin ( BT resin), polyamide imide, polyarylate aromatic polyester, polyether ether ketone, polyether imide, polyether ketone, polyether nitrile, polyether sulfone, polyketone, polyphenylene ether, polysulfone and the like.

The material of the lower electrode 21 is not particularly limited as long as it is a conductive material. For example, conductive materials such as copper, gold, silver, palladium, nickel, titanium, and alloys of two or more of these can be used. Lower electrode 2
The size and shape of 1 are not particularly limited, and various shapes such as a circular shape, an elliptical shape, and a rectangular shape can be formed in a desired size. The lower electrode 21 may be formed of a single layer or a plurality of layers of two or more layers.

The lower electrode 21 may be formed separately from the lower conductor circuit layer 51, but it is preferably formed at the same time in order to improve productivity. As a method of forming both simultaneously, for example, a subtractive method of forming a pattern by etching a copper clad laminate having a copper foil on the resin substrate surface, only electroless plating using an electrically insulating substrate as a starting material, Alternatively, an additive method of forming a pattern by using electroplating together may be used. The pattern configuration and the like can be the same as those used in a normal multilayer circuit.

As described above, the states shown in FIGS. 2A and 2A 'are obtained. In the present embodiment, FIG.
As shown in (a '), the lower electrode 21 is formed in a circular shape.

The thickness of the substrate (hereinafter referred to as "inner layer substrate") obtained by forming the lower conductor circuit layer 51 and the lower electrode 21 on the surface of the core material 11 is usually 50 μm to 2 m.
m, preferably 60 μm to 1.6 mm, more preferably 100 μm to 1 mm. Specific examples of such an inner layer substrate include a printed wiring board and a silicon wafer substrate.

In this embodiment, the lower conductor circuit layer 51
The case where the above is formed on one surface of the core material 11 will be described as an example, but the printed wiring board can be manufactured in the same manner when the lower conductor circuit layer 51 and the like are formed on both surfaces of the core material 11.

Further, the surface of the inner layer substrate is preferably subjected to surface roughening in order to enhance the adhesion strength with the interlayer insulating layer laminated in the next step. Examples of the method of roughening the surface include (i) a method of micro-etching the surface, (ii) a method of treating the surface with permanganate, and (iii) a method of contact treatment with plasma.

(B) Step (2) of Forming Interlayer Insulating Layer Next, as shown in FIG. 2B, an alicyclic olefin polymer is formed on the lower electrode 21 formed in the step (1). An interlayer insulating layer 31 is formed by curing a curable composition containing a curing agent.

The curable composition used in the present invention contains an alicyclic olefin polymer and a curing agent. The alicyclic olefin polymer is a polymer having a structural unit derived from an alicyclic structure-containing olefin monomer (hereinafter referred to as “alicyclic olefin monomer”). The alicyclic structure contained in the alicyclic olefin monomer is polycyclic (condensed polycyclic, bridged ring, polycyclic combination thereof, etc.) even if it is monocyclic.
May be From the viewpoint of mechanical strength, heat resistance and the like, polycycles are preferable.

Further, the aromatic ring of a polymer obtained by addition-polymerizing an aromatic olefin such as styrene, α-methylstyrene, divinylbenzene, vinylnaphthalene and vinyltoluene is hydrogenated to give alicyclic olefin unit amount. A polymer in which the same structural unit as the body-derived structural unit is formed can also be used as the alicyclic olefin polymer. Further, the alicyclic olefin polymer may be obtained by copolymerizing an alicyclic olefin monomer and a monomer copolymerizable therewith (for example, ethylene).

The ratio of the structural unit derived from the alicyclic olefin monomer in the alicyclic olefin polymer is appropriately selected according to the purpose of use, but is usually 30 to 100% by weight, preferably 50 to 100% by weight. %, More preferably 70 to 100% by weight. If the proportion of the structural unit derived from the alicyclic olefin monomer is excessively low, the heat resistance becomes poor, which is not preferable.

The alicyclic olefin polymer preferably has a polar group. As the polar group, a hydroxyl group,
Examples thereof include a carboxyl group, an alkoxyl group, an epoxy group, a glycidyl group, an oxycarbonyl group, a carbonyl group, an amino group, an ester group, and a carboxylic acid anhydride group. Among these, phenolic hydroxyl groups,
Acidic groups such as carboxyl groups or carboxylic acid anhydride groups are preferred.

The method for obtaining the alicyclic olefin polymer is not particularly limited. As a method for obtaining an alicyclic olefin polymer having no polar group, for example, an alicyclic olefin monomer having no polar group is subjected to addition polymerization or ring-opening polymerization by a known method, and if necessary. Depending on the method, the unsaturated bond portion may be hydrogenated.

Examples of the alicyclic olefin monomer having no polar group include bicyclo [2.2.1] -hept-
2-ene, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene, tetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ]
Examples include dodeca-3-ene and cyclopentadiene.

In the case of producing an alicyclic olefin polymer by ring-opening polymerization, the use of α-olefin such as 1-hexene as a molecular weight modifier facilitates control of the molecular weight.

Examples of the method for obtaining the alicyclic olefin polymer having a polar group include the following two methods. First, an alicyclic olefin polymer having no polar group obtained by the above-mentioned method is used in the presence of a radical initiator to prepare an unsaturated carboxylic acid compound, an ester or amide of an unsaturated carboxylic acid compound, or an acid. This is a method of modifying with a polar group-containing compound such as an anhydride (WO01 / 79325, etc.).

Here, examples of the unsaturated carboxylic acid compound include acrylic acid, methacrylic acid, α-ethylacrylic acid, 2-hydroxyethyl (meth) acrylic acid,
Maleic acid, fumaric acid, itaconic acid, endocis-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid, methyl-endocis-bicyclo [2.2.1]
Hept-5-ene-2,3-dicarboxylic acid or the like can be used. As the acid anhydride, for example, maleic anhydride, chloromaleic anhydride, butenyl succinic anhydride, tetrahydrophthalic anhydride, citraconic anhydride, etc. can be used.

Secondly, the alicyclic olefin monomer having no polar group as described above and the alicyclic olefin monomer having a polar group are optionally added in the presence of a molecular weight modifier. And a method of copolymerization (JP-A-11-52574).
Gazette, Japanese Patent Application No. 2001-174872).

Alicyclic olefin monomer containing polar group
Is, for example, 8-methyl-8-methoxycarbonyl
Rutetracyclo [4.4.0.1^2,5． 1^{7, 10}]
Dodeca-3-ene, 5-hydroxyethoxycarbonyl
Bicyclo [2.2.1] hept-2-ene, 8-hydro
Xymethyltetracyclo [4.4.0.1^2,5． 1
^{7, 10}] Dodeca-3-ene, 5,6-dihydroxyme
Cylbicyclo [2.2.1] hept-2-ene, 5,6
-Diacetyloxymethylbicyclo [2.2.1] hep
To-2-ene, 5-t-butoxycarbonylbicyclo
[2.2.1] Hept-2-ene and the like can be mentioned.

Examples of the alicyclic olefin polymer thus obtained include ring-opening polymers of alicyclic olefin monomers and hydrogenated products thereof, addition polymers of alicyclic olefin monomers, Addition polymer of alicyclic olefin monomer and vinyl compound, monocyclic cycloalkene polymer, alicyclic conjugated diene polymer, vinyl alicyclic hydrocarbon polymer and hydrogenated product thereof, aromatic olefin polymer Examples include a combined aromatic ring hydrogenated product. Among these, ring-opening polymers of alicyclic olefin monomers and hydrogenated products thereof, addition polymers of alicyclic olefin monomers, addition polymers of alicyclic olefin monomers and vinyl compounds, An aromatic ring hydrogenated product of an aromatic olefin polymer is preferable, and a hydrogenated product of a ring-opening polymer of an alicyclic olefin monomer is particularly preferable.
The alicyclic olefin polymer may be used alone or in combination of two or more kinds.

The glass transition temperature of the alicyclic olefin polymer can be appropriately selected according to the purpose of use, but is usually 50 ° C. or higher, preferably 70 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 125 ° C. or higher. is there.

There is no particular limitation on the curing agent blended in the curable composition, and for example, an ionic curing agent, a radical curing agent, or a curing agent having both ionic and radical properties is used.

Examples of the curing agent include 1-allyl-
Nitrogen-based curing agents such as halogen-free isocyanurate-based curing agents containing an allyl group and an epoxy group such as 3,5-diglycidyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; bisphenol A
Bis (ethylene glycol glycidyl ether) ether, bisphenol A bis (diethylene glycol glycidyl ether) ether, bisphenol A bis (triethylene glycol glycidyl ether) ether,
Bisphenol A Bis (propylene glycol glycidyl ether) ether and other bisphenol A glycidyl ether type epoxy compounds such as glycidyl ether type epoxy compounds, alicyclic epoxy compounds, glycidyl ester type epoxy compounds and other polyvalent epoxy compounds; acid anhydrides And dicarboxylic acid derivatives such as dicarboxylic acid compounds; polyol compounds such as diol compounds, triol compounds and polyhydric phenol compounds; and the like. Among these, polyvalent epoxy compounds are preferable,
Particularly, a glycidyl ether type epoxy compound is preferable from the viewpoint of enhancing crack resistance.

These curing agents can be used alone or in combination of two or more. The amount of the curing agent added is usually 5 to 150 parts by weight, preferably 15 to 11 parts by weight, based on 100 parts by weight of the alicyclic olefin polymer.
The amount is 0 parts by weight, more preferably 30 to 100 parts by weight.

The curable composition may further contain a curing accelerator in order to accelerate the curing reaction between the alicyclic olefin polymer and the curing agent. As the curing accelerator, for example, when the curing agent is a polyvalent epoxy compound,
Tertiary amines such as chain-like tertiary amine compounds, pyrazoles, pyridines, pyrazines, pyrimidines, indazoles (1-benzyl-2-phenylimidazole, etc.), quinolines, isoquinolines, imidazoles, triazoles, etc. It is preferable to use a system compound or a boron trifluoride complex compound. Above all, it is preferable to use a curing accelerator such as a tertiary amine compound because the lamination properties for fine wiring, insulation resistance, heat resistance and chemical resistance are improved.

The curing accelerators can be used alone or in combination of two or more kinds. The compounding amount of the curing accelerator is appropriately selected according to the purpose of use, but is usually 0.001 to 100 parts by weight with respect to 100 parts by weight of the alicyclic olefin polymer.
30 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight.

If necessary, a curing aid can be added to the curable composition. Specific examples of the curing aid include quinone dioxime, benzoquinone dioxime, p-
Oxime / nitroso-based curing aids such as nitrosophenol; Maleimide-based curing aids such as N, Nm-phenylene bismaleimide; Allyl-based curing aids such as diallyl phthalate, triallyl cyanurate, and triallyl isocyanurate; ethylene Methacrylate-based curing aids such as glycol dimethacrylate and trimethylolpropane trimethacrylate; vinyl-based curing aids such as vinyltoluene, ethylvinylbenzene, divinylbenzene; 1
Examples thereof include tertiary amine compounds such as benzyl-2-phenylimidazole. In addition, a peroxide that functions as a curing aid for a curing agent having an allyl group can be used.

If desired, other components may be added to the curable composition. For example, a compound having absorption in the wavelength region of a laser beam used when forming a hole such as a via hole or an interlayer connector can be blended. Further, for example, when the YAG second harmonic is used, it is preferable to use a dye. When using a composition containing a compound having absorption in the wavelength region of the laser beam,
Hole formation by laser is easy and smear is less likely to occur.

In addition to these, the above-mentioned curable composition also includes a flame retardant, a soft polymer, a heat stabilizer, a weather stabilizer, an antiaging agent, a leveling agent, an antistatic agent, a slip agent, an antiblocking agent, Antifog agents, lubricants, pigments, natural oils, synthetic oils, waxes, emulsions, fillers and the like can be added as other components. The blending ratio is appropriately selected within a range that does not impair the object of the present invention.

Interlayer insulating layer 3 obtained by curing a curable composition
There is no particular restriction on how to get 1. For example, it can be obtained by laminating a molded body obtained by molding the above-mentioned curable composition in a film shape or a sheet shape on an inner layer substrate and then heating it to cure the curable composition.

The film-like or sheet-like molded product of the curable composition (hereinafter sometimes simply referred to as "molded product") is usually molded into a film or sheet by a solution casting method or a melt casting method. Is. In the case of molding by the solution casting method, the organic solvent is dried and removed after applying the varnish to the support.

The support used in the solution casting method may, for example, be a resin film (carrier film) or a metal foil. As the resin film, usually, a thermoplastic resin film is used, and specifically, a polyethylene terephthalate film, a polypropylene film, a polyethylene film, a polycarbonate film, a polyethylene naphthalate film, a polyarylate film,
Examples include nylon film. Among these,
A polyethylene terephthalate film and a polyethylene naphthalate film are preferable from the viewpoints of heat resistance, chemical resistance, peelability after lamination and the like. As the metal foil, for example,
Examples include copper foil, aluminum foil, nickel foil, chrome foil, gold foil, silver foil and the like. A copper foil, particularly an electrolytic copper foil or a rolled copper foil, is preferable because it has good conductivity and is inexpensive. The thickness of the support is not particularly limited, but from the viewpoint of workability and the like, it is usually 1 μm to 150 μm, preferably 2 μm to 100 μm,
More preferably, it is 3 μm to 50 μm.

There is no particular limitation on the method for obtaining the varnish, and the varnish can be obtained, for example, by mixing each component constituting the curable composition with an organic solvent. The mixing method of each component may be according to a conventional method, for example, stirring using a stirrer and a magnetic stirrer, high-speed homogenizer, dispersion, planetary stirrer, twin-screw stirrer, ball mill,
It can be performed by a method using a triple roll or the like. The temperature at the time of mixing these is within the range where the reaction with the curing agent does not affect workability, and from the viewpoint of safety, it is preferably not higher than the boiling point of the organic solvent used at the time of mixing.

Examples of the organic solvent include aromatic hydrocarbon organic solvents such as toluene, xylene, ethylbenzene and trimethylbenzene; aliphatic hydrocarbon organic solvents such as n-pentane, n-hexane and n-heptane; cyclo. Alicyclic hydrocarbon-based organic solvents such as pentane and cyclohexane; halogenated hydrocarbon-based organic solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; ketone-based organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone Can be used. These organic solvents can be used alone or in combination of two or more kinds.

Among these, a non-polar organic solvent such as an aromatic hydrocarbon-based organic solvent or an alicyclic hydrocarbon-based organic solvent is used because it is excellent in embedding in fine wiring and does not generate bubbles. It is preferable to use a mixed organic solvent in which a polar organic solvent such as a ketone organic solvent is mixed. The mixing ratio of the non-polar organic solvent and the polar organic solvent can be appropriately selected, but the weight ratio is usually 5:95 to 95: 5, preferably 10:90 to 90:10, more preferably 20:80 to.
The range is 80:20.

The amount of the organic solvent used is appropriately selected depending on the purpose of controlling the thickness and improving the flatness, but the solid content concentration of the varnish is usually 5 to 70% by weight, preferably 10 to 6%.
It is 5% by weight, more preferably 20 to 60% by weight.

The method of applying the varnish to the support is not particularly limited, and known coating methods such as a dip coating method, a roll coating method, a curtain coating method, a die coating method and a slit coating method can be used.

The conditions for removing and drying the organic solvent can be appropriately selected depending on the type of the organic solvent. The drying temperature is usually 20 to 300 ° C, preferably 30 to 200 ° C,
The drying time is usually 30 seconds to 1 hour, preferably 1 to 3
0 minutes.

The thickness of the obtained film or sheet is usually 0.1 to 150 μm, preferably 0.5 to 100 μm.
m, and more preferably 1.0 to 80 μm. When a film or sheet is desired to be obtained alone, it is peeled from the support after forming the film or sheet on the support.

In order to laminate a film or sheet obtained by forming a curable resin composition on an inner layer substrate, usually, a film or sheet having a support is laminated so that the film or sheet is in contact with the inner layer substrate surface. In addition, it may be heated and pressure bonded using a pressure machine such as a pressure laminator, a press, a vacuum laminator, a vacuum press, a roll laminator. The thermocompression bonding is preferably performed under vacuum in order to improve the embedding property in the wiring and suppress the generation of bubbles and the like. The temperature during thermocompression bonding is usually 30 to 250 ° C., preferably 70 to 250 ° C.
200 ° C., pressure bonding force is usually 10 kPa to 20 MPa, preferably 100 kPa to 10 MPa, pressure bonding time is usually 30 seconds to 5 hours, preferably 1 minute to 3 hours, usually 100 kPa to 1 Pa, preferably 40 kPa to 10 P.
The atmosphere is depressurized to a.

In order to cure the curable composition,
The curable composition is heated. The curing conditions are appropriately selected depending on the type of the curing agent, but the temperature for curing is usually 30 to 400 ° C, preferably 70 to 300 ° C, more preferably 100 to 200 ° C, and the curing time is Normally 0.
It is 1 to 5 hours, preferably 0.5 to 3 hours.

When the film or sheet with the support is laminated on the inner layer substrate, the film or sheet made of the curable composition may be heated and cured with the support still attached, but it is usually used. After the support is peeled off, a film or sheet made of the curable composition is heated to cure the curable composition.

The interlayer insulating layer 31 can be formed as described above (FIG. 2B). Interlayer insulating layer 3 to be formed
The thickness of 1 is not particularly limited, but is usually 10 to 200 μ.
m, preferably 15 to 100 μm.

(C) Step (3) of Forming Capacitor Element Next, the interlayer insulating layer 3 formed in the step (2).
A capacitor element is formed by forming the upper electrode 41 on the first electrode 1. This step can be performed as follows. First, as shown in FIG. 3C, a via hole 61 is formed in a predetermined portion of the interlayer insulating layer 31. Laser light is preferably used to form the via hole 61. 0.01mm diameter by using laser light
Level processing is possible. The laser used is
Examples thereof include YAG laser, carbon dioxide gas laser, excimer laser and the like. After performing the laser processing, a treatment for removing a resin residue in the hole, for example, a desmear treatment can be performed if necessary. The diameter of the via hole 61 is formed to be smaller than the diameter of the end portion 51 ′ (circular shape, FIG. 2A ′) of the lower conductor circuit layer 51.

Next, as shown in FIG. 3D, a base film 81 is formed inside the via hole 61 and on the surface of the interlayer insulating layer 31 as required. The base film 81 is formed to enhance the adhesion between the interlayer insulating layer 31, the upper electrode 41 and the upper conductor circuit layer 71. The material of the base film 81 is not particularly limited as long as it is a conductive metal. For example,
Examples include nickel, copper, aluminum, chromium, and alloys of two or more of these metals. Above all, it is preferable to use an alloy that is more excellent in adhesion between the interlayer insulating layer 31 and the upper conductor circuit layer 71, and when forming the upper conductor circuit layer 71 by copper plating, it is more preferable to use a nickel-chromium alloy. It is particularly preferable that the copper layer is formed on the alloy to form two layers.

The base film 81 can be formed by a known film forming method such as a sputtering method, an ion plating method, a vapor deposition method and a CVD method. Base film 8
The thickness of 1 (total thickness in the case of being composed of a plurality of layers) is usually 0.1 to 0.5 μm.

Next, as shown in FIG. 3E, a conductive layer 91 is formed on the surface of the base film 81. The conductive layer 91 can be formed by performing electroplating to a desired thickness. The thickness of the plating film is 50 μm for the wiring width / wiring interval
In the case of a fineness of about / 50 μm, a thickness of 15 μm or less is desirable.

Further, the conductive layer 91 is patterned to form the upper conductor circuit layer 71 and the upper electrode 41 while leaving the underlying film in the portion where the upper conductor circuit layer 71 and the upper electrode 41 are to be formed. In this case, when forming the upper conductor circuit layer 71 and the upper electrode 41, the upper electrode is patterned while leaving the base film in the portion where the thin film resistor is to be formed, and then the thin film resistor is formed. It is preferable to form a thin-film resistor made of a nickel alloy by selectively etching only the copper of the underlying film in an appropriate portion. As described above, the printed wiring board having the structure shown in FIG. 1A can be obtained.

In the method for manufacturing a printed wiring board of the present invention, after the step (1) of patterning the lower electrode and before the step (2) of forming an interlayer insulating layer,
A step (1 ′) of forming a capacitor insulating layer having a dielectric constant higher than that of the interlayer insulating layer is further provided on the lower electrode pattern, and after the step (2) of forming the interlayer insulating layer, Before the step (3) of forming the capacitor element, it is preferable to further include a step (2 ′) of polishing the surface of the interlayer insulating layer to expose the capacitor insulating layer.

Specifically, these steps can be performed as follows. First, as shown in FIG. 4A, a substrate (inner layer substrate) in which the lower electrode 22 and the lower conductor circuit layer 52 are formed on the core material 12 is prepared.

Next, as shown in FIG. 4B, a capacitor insulating layer 33 made of a high dielectric constant material is formed on the lower electrode 22.
To form. The high dielectric constant material is not particularly limited as long as it is a material capable of forming the capacitor insulating layer 33 having a higher dielectric constant than the interlayer insulating layer 32. Examples of such a material include barium titanate (BaT).
a high dielectric material typified by iO ₃ ) or an epoxy resin, polyphenylene ether (PPE),
A mixture with an organic material such as polyimide can be used. The capacitance of the capacitor can be changed by a method such as changing the content of the high dielectric material contained in the organic material.

As a method of forming the capacitor insulating layer 33, for example, there is a method of applying a paste made of a high dielectric constant material by a screen printing method and then hardening it. The curing may be performed before the next step of forming the interlayer insulating layer 32 or at the same time as the formation of the interlayer insulating layer 32. The amount of paste applied is not particularly limited, but is usually an amount proportional to the size and height of the capacitor insulating layer 33.

Further, in this case, as shown in FIG.
As shown in (b ″), it is preferable to form a dam pattern 34 so as to surround the lower electrode 22 before forming the capacitor insulating layer 33. The dam pattern 34 is formed in advance. By setting it, the dam pattern can prevent the paste from flowing out, so that the capacity accuracy can be further improved, and a paste material having a low viscosity (low thixotropy) can be supplied by using a dispenser. .

Then, as shown in FIG.
In the same manner as in the production of the printed wiring board shown in (a), the curable composition containing the alicyclic olefin polymer and the curing agent is cured to form the interlayer insulating layer 32. in this case,
In order to reduce undulations and unevenness generated by laminating the interlayer insulating layer 32 on the high dielectric constant paste material,
It is desirable to make the surface as flat as possible under pressure, temperature, and lamination (or laminating) conditions such as multi-step pressing.

Further, the interlayer insulating layer 32 and the high dielectric constant capacitor insulating layer 33 are polished together until the high dielectric constant paste material is exposed and the required capacitance value is reached.
By doing so, variation in capacitance value can be reduced by controlling the thickness (FIG. 5D). Examples of the polishing method include a method using a buff excellent in leveling property.

After that, as shown in FIG.
As in the case of manufacturing the printed wiring board shown in (a), the via hole 6 is formed by irradiating a predetermined portion of the interlayer insulating layer 32 with laser light.
Form 2. Further, a base film (not shown) and a conductive layer (not shown) are sequentially formed inside the via hole 62 and on the surface of the interlayer insulating layer 32, and under the portion where the upper conductor circuit layer 72 and the upper electrode 42 are to be formed. The conductive layer is patterned to form the upper conductor circuit layer 72 and the upper electrode 42 while leaving the ground film. As described above, FIG.
A printed wiring board having the structure shown in (b) can be obtained.

The printed wiring board of the present invention thus obtained is used as a printed wiring board for mounting a semiconductor element such as a CPU or a memory or other mounting parts in an electronic device such as a computer or a mobile phone. be able to. In particular, one having a fine structure can be suitably used as a high-density printed wiring board or a wiring board for a computer or a mobile terminal used in a high frequency region.

[0072]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. In the examples, part and% are
Unless otherwise specified, it is based on weight. The evaluation method used in this example is as follows. (1) The molecular weight was measured as a polystyrene conversion value by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. (2) Hydrogenation rate and (anhydrous) maleic acid residue content rate Hydrogenation rate (hydrogenation rate) relative to the number of moles of unsaturated bonds in the polymer before hydrogenation, and the total number of monomer units in the polymer The ratio of the number of moles of the (anhydrous) maleic acid residue (carboxyl group content rate) was measured by ¹ H-NMR spectrum. (3) Glass transition temperature (Tg) It was measured by a differential scanning calorimetry (DSC method).

(Production Example) 8-Ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodeca-3-
Ring-opening polymerization of ene followed by hydrogenation reaction, number average molecular weight (Mn) = 31,200, weight average molecular weight (M
A hydrogenated polymer having w) = 55,800 and Tg = about 140 ° C. was obtained. The hydrogenation rate of the obtained polymer was 99% or more. The obtained polymer (100 parts), maleic anhydride (40 parts) and dicumyl peroxide (5 parts) were dissolved in t-butylbenzene (250 parts), and the mixture was reacted at 140 ° C for 6 hours. The obtained reaction product solution was poured into 1000 parts of isopropyl alcohol to coagulate the reaction product to obtain a maleic acid-modified hydrogenated polymer. This modified hydrogenated polymer is heated to 100 ° C.
It was vacuum dried for 20 hours. The molecular weight of this modified hydrogenated polymer was Mn = 33,200, Mw = 68,300, and Tg
Was 170 ° C. (Anhydrous) Maleic acid residue content is 2
It was 5 mol%.

100 parts of the modified hydrogenated polymer, 40 parts of bisphenol A bis (propylene glycol glycidyl ether) ether, 2- [2-hydroxy-3,5-
5 parts of bis (α, α-dimethylbenzyl) phenyl] benzotriazole and 0.1 part of 1-benzyl-2-phenylimidazole and a dye (trade name: Kayaset
Blue A-2R, manufactured by Nippon Kayaku Co., Ltd., was dissolved in a mixed solvent consisting of 215 parts of xylene and 54 parts of cyclopentanone to obtain a varnish of a curable resin composition.

Example 1 Manufacturing of Printed Wiring Board Example 1 is an example of manufacturing a printed wiring board having a structure similar to that shown in FIG.

(Lower electrode patterning step) Double-sided copper foil laminate (MCL-E-679F manufactured by Hitachi Chemical Co., Ltd.,
A lower electrode and a lower conductor circuit layer are formed by a subtractive method on a copper thickness of 12 μm and a plate thickness of 0.6 mm, and then, in order to obtain adhesion between the formed pattern and an insulating layer, MEC Etch Bond CZ-8100 (MEC Etch Bond CZ-8100). (Made by)
Was used for surface roughening.

(Interlayer Insulating Layer Forming Step) The printed board obtained above is sandwiched with the dry film with a carrier film obtained in Production Example so that the molded body side is in contact with the board, and the board and the dry film are heated and pressed. The squares were fixed with polyimide tape so that they would not come apart. Using a vacuum laminator equipped with heat-resistant rubber press plates at the top and bottom, the pressure was reduced to 200 Pa, the temperature was 115 ° C., and the pressure was 0.5 MPa.
It was thermocompression bonded for 120 seconds. Then, using a laminating apparatus having upper and lower heat-resistant rubber press plates covered with stainless steel press plates, the temperature was 125 ° C. and the pressure was 0.5 MPa.
It was thermocompression bonded for 0 seconds. After that, only the carrier film was peeled off and cured in a nitrogen oven at 150 ° C. for 120 minutes to form an interlayer insulating layer.

(Laser via processing step) Next, a laser via hole was formed by irradiating a portion to be laser via hole processed with YAG laser light. The processing conditions are as follows. YAG wavelength: Double wave (532 nm) Laser power: 1.8 W Repetition frequency: 35 kHz Irradiation mode: Burst pulse width: 1.75 nsec Number of shots: 20-30

By performing laser processing under the above conditions, excellent laser via processing with an opening diameter of 50 μm and a hole bottom diameter of 40 μm was achieved.

(Step of forming metal thin film by sputtering) Process pressure 10 Pa, RF power 100 W, O ₂
After performing reverse sputtering for 1 minute in an atmosphere, a nickel-chromium alloy film (which is an adhesion layer between resin and copper) is formed by a DC sputtering method at a process pressure of 0.4 Pa, a DC power of 400 W, and a rate of 5 Å / sec. NiC
An r alloy film) and a copper film (Cu film) were sequentially formed (thickness: about 0.1 μm) in an argon atmosphere.

(Upper Electrode Forming Step) After that, a copper film is formed to a thickness of 20 μm by electrolytic plating, and then an unnecessary portion of the electrolytic plated layer is removed together with the metal thin film formed by sputtering by the subtractive method. A circuit layer was formed to obtain a printed wiring board having a built-in capacitor.

The capacitor capacity, dielectric constant and dielectric loss of the obtained printed wiring board were tested in a high temperature and high humidity test (85 ° C., 85 ° C.).
%, 192 hours) before and after, and the change rate of each was calculated. The rate of change is a value obtained by the formula: rate of change (%) = [(value before test−value after test) / value before test] × 100.

The capacitance, dielectric constant and dielectric loss of the printed wiring board were measured by measuring the 27.5 μm capacitor element sandwiched between 1.2 mm × 1.2 mm electrodes with ICM.
HP / 419 manufactured by Hured Packer Co. using P / N A0123614 and A0109242B probes.
It was measured with a 2LF impedance analyzer. The measurement results are shown in Table 1.

Comparative Example 1 Production of Printed Wiring Board Instead of forming the interlayer insulating layer with the dry film with a carrier film obtained in Production Example, a commercially available thermosetting epoxy ink was used to form a coating film by a screen printing method. Then, a printed wiring board having a built-in capacitor was obtained in the same manner as in Example 1 except that the interlayer insulating layer was formed by curing at 100 ° C. for 30 minutes.

As in Example 1, the capacitance, dielectric constant and dielectric loss of the obtained printed wiring board were measured before and after the high temperature and high humidity test (85 ° C., 85%, 192 hours). The results are shown in Table 1.

[0086]

[Table 1]

Example 2 Manufacturing of Printed Wiring Board Example 2 is an example of manufacturing a printed wiring board having a structure similar to that shown in FIG.

Double-sided copper foil laminate (product number: MCL-E-
679F, Hitachi Chemical Co., Ltd., copper thickness 12 μm, plate thickness 0.6 mm), a lower electrode, an inner layer pattern and a dam pattern are formed by a subtractive method, and then the formed pattern and the insulating layer are adhered to each other. MEC Etch Bond CZ-8100 (Mec Co., Ltd.)
(Manufactured by K.K.) was used for surface roughening.

Barium titanate powder having a particle size of 1 μm or less
1: 1 (weight ratio) of novolac resin and phenol resin
50% by weight was added to the mixed resin to obtain a derivative paste.
This paste was applied on the lower electrode by a screen printing method to a thickness of about 30 μm, and heat-cured at 150 ° C. for 2 hours to form a capacitor insulating layer.

The obtained printed circuit board was sandwiched by the dry film with a carrier film obtained in Production Example so that the molded product side was in contact with the substrate, and the squares were made of polyimide to prevent the substrate and the dry film from being displaced during heating and pressurization. I fixed it with tape. Using a vacuum laminator equipped with heat-resistant rubber press plates at the top and bottom, the pressure was reduced to 200 Pa at a temperature of 1
It was thermocompression bonded at 15 ° C. and a pressure of 0.5 MPa for 120 seconds.
Then, only the carrier film was peeled off and cured in a nitrogen oven at 150 ° C. for 120 minutes to form an interlayer insulating layer.

Next, the capacitor insulating layer was exposed by polishing it flat with a buff (# 800). Further, a YAG laser beam was applied to a portion to be laser via hole processed to form a laser via hole. The processing conditions are the same as in Example 1. By laser processing, excellent laser via processing with an opening diameter of 50 μm and a hole bottom diameter of 40 μm was achieved.

Thereafter, after performing reverse sputtering for 1 minute in an O 2 atmosphere with a process pressure of 10 Pa and an RF power of 100 W, a process pressure of 0.4 Pa and a DC power of 400 W, 5
A NiCr alloy film and a Cu film, which form an adhesion layer of the resin and copper, were sequentially formed under an argon atmosphere by a DC sputtering method with a rate of angstrom / sec (each having a thickness of about 0.1 μm).

After that, copper is formed to a thickness of 20 μm by electroplating, and then unnecessary portions of the electroplating layer are removed together with the metal thin film formed by the sputtering method by the subtractive method to form the upper electrode and the upper conductor circuit layer. A printed wiring board with a built-in capacitor having a small area and a large capacitor capacity was obtained.

[0094]

As described above, according to the printed wiring board and the method of manufacturing the same of the present invention, a printed wiring board having a built-in capacitor having a stable capacitor capacity without being affected by the environment such as humidity, and the same. A manufacturing method is provided.

[Brief description of drawings]

FIG. 1 is a structural cross-sectional view of a printed wiring board of the present invention.

2A and 2B are process cross-sectional views of the method for manufacturing a printed wiring board according to the present invention, and FIG. 2A 'is a process top view.

3 (c) to 3 (e) are process cross-sectional views of a method for manufacturing a printed wiring board according to the present invention.

4 (a) and 4 (b) are process cross-sectional views of the method for manufacturing a printed wiring board according to the present invention, and FIG. 4 (b ') shows a dam insulating pattern 33 formed by forming a dam pattern 34. And FIG. 4B ″ is a top view thereof.

5 (c) to 5 (e) are process cross-sectional views of a method for manufacturing a printed wiring board according to the present invention.

[Explanation of symbols]

11,12 ... Core material 21,22 ... Lower electrode, 31, 3
2 ... Interlayer insulating layer, 33 ... Capacitor insulating layer, 34 ... Dam pattern, 41, 42 ... Upper electrode, 51, 52 ... Lower conductor circuit layer, 51 '... End portion of lower conductor circuit layer, 61, 6
2 ... Via holes, 71, 72 ... Upper conductor circuit layer, 81 ...
Base film, 91 ... Conductive layer

Continued front page    (72) Inventor Hisanori Yoshimizu             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi Japan             Victor Co., Ltd. (72) Inventor Shigeru Dowaki             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi Japan             Victor Co., Ltd. F-term (reference) 4E351 AA03 BB03 BB05 BB30 BB35                       CC02 CC03 DD04 GG09                 5E346 AA12 AA13 AA15 AA32 AA33                       CC08 CC21 CC32 DD02 DD03                       DD32 EE06 EE08 FF07 FF14                       GG08 GG17 GG22 GG28 HH06                       HH31

Claims (5)

[Claims] 1. A method of manufacturing a printed wiring board having a capacitor element, the method comprising the step of patterning a lower electrode on a portion of the substrate where the capacitor element is to be formed,
A step (2) of forming an interlayer insulating layer obtained by curing a curable composition containing an alicyclic olefin polymer and a curing agent on the lower electrode formed in the step (1);
A method of manufacturing a printed wiring board, comprising the step (3) of forming a capacitor element by patterning an upper electrode on the interlayer insulating layer formed in the step (2). 2. After the step (1) of patterning the lower electrode and before the step (2) of forming an interlayer insulating layer,
After the step (1 ′) of forming a capacitor insulating layer having a higher dielectric constant than that of the interlayer insulating layer on the lower electrode, and the step (2) of forming the interlayer insulating layer, 2. The step (2 ′) according to claim 1, further comprising a step (2 ′) of polishing the surface of the interlayer insulating layer to expose the capacitor insulating layer before the step (3) of forming a capacitor element. Method for manufacturing printed wiring board. 3. A step of forming a dam pattern surrounding the lower electrode after the step (1) of patterning the lower electrode and before the step (2 ′) of forming the capacitor insulating layer. The method for manufacturing a printed wiring board according to claim 2, further comprising: 4. A step (3) of forming the capacitor element
However, a base film consisting of two layers of nickel alloy and copper is patterned on the surface of the interlayer insulating layer and / or the capacitor insulating layer, and then the upper electrode is left in a state where the base film of the portion where the thin film resistance is to be formed is left. The method further comprises forming a thin film resistor made of a nickel alloy by patterning, and selectively etching only the copper of the base film in the portion where the thin film resistor is to be formed.
A method for manufacturing a printed wiring board according to any one of 1. 5. A printed wiring board manufactured by the method for manufacturing a printed wiring board according to claim 1.