JP2003105205A - High dielectric constant composite material, high dielectric constant film, laminate board with metal foil and print circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high dielectric constant composite material excellent in dielectric performance, hardly causing a crack even when exposed to temperature histories, to prepare a high dielectric constant film, and to provide a laminate board with a metal foil and a print circuit board formed by using the composite material. SOLUTION: The high dielectric constant composite material comprises (A) a thermosetting resin such as an epoxy resin, (B) a phenoxy resin or a thermoplastic resin such as polyethersulfone or polyimide, (C) a dielectric filler as indispensable components, wherein the thermoplastic resin (B) is 10 to 50 mass% to the total resin solid content. The cured product of the composite material is excellent in dielectric performance and hardly causes crack even exposed to temperature histories. Also, the high dielectric constant film, the laminate board with the metal foil and the print circuit board formed by using the composite material, possess both toughness and adhesivity with metal foils. Preferably, the dielectric filler (C) is 30 to 90 mass% to the total solid content.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a high-dielectric-constant composite material, a high-dielectric-constant film formed using the same, a laminated board with a metal foil, and a printed wiring board.

[0002]

2. Description of the Related Art In recent years, the speed of signal transmission in electronic equipment has been increased, but this causes a problem that electrical noise increases. As a means for satisfying this problem, a method of mounting a chip capacitor or the like on a printed wiring board has been conventionally adopted, but mounting it on the printed wiring board hinders downsizing of the wiring board or lengthens the wiring length. Therefore, it is preferable to form a capacitor in the substrate.

Further, despite the increase in the number of parts to be mounted on a printed wiring board in order to improve the performance of electronic equipment, the printed wiring board is required to be small and lightweight. Since the area on the printed wiring board is limited, how to reduce the mounting area of electronic parts is a problem for miniaturization. As a means for satisfying this problem, there has been developed a technique for forming passive elements such as capacitors, inductances, and resistors, which are conventionally mounted on a printed wiring board, inside the printed wiring board.

When a capacitor is provided on a printed wiring board, it is necessary to provide a dielectric layer. In the case of an organic substrate, this layer can be formed by sputtering, the CVD method or the sol-gel method, but from the viewpoint of cost etc., it is better than a composite material in which a dielectric filler is filled in a thermosetting resin or a thermoplastic resin. It is common to provide the formed high dielectric layer (see Japanese Patent Laid-Open No. 9-12742). Further, in order to obtain a high dielectric constant, it is necessary to fill the dielectric filler with 50% by mass or more of the total solid content (see JP-A-10-208548).

[0005]

However, a high dielectric constant composite material obtained from a thermosetting resin and a high dielectric filler is apt to crack when subjected to a temperature history, and is obtained from a thermoplastic resin and a high dielectric filler. The high-dielectric-constant composite material has a drawback that it has low adhesion to the metal foil. The present invention is excellent in dielectric properties to solve the above problems, a high dielectric constant composite material which hardly causes cracks even when subjected to a temperature history and a high dielectric constant film formed using the same, a laminated sheet with a metal foil, a print To provide a wiring board.

[0006]

The invention according to claim 2 provides (A) a thermosetting resin, (B) a thermoplastic resin, and (C).
A high dielectric constant composite material comprising a dielectric filler as an essential component and (B) a thermoplastic resin in an amount of 10 to 50% by mass based on the total resin solid content. The invention according to claim 2 is the high dielectric constant composite material according to claim 1, wherein the (C) dielectric filler is 30 to 90 mass% with respect to the total solid content. The invention according to claim 3 is the high dielectric constant composite material according to any one of claims 1 and 2, wherein the thermosetting resin (A) is an epoxy resin. The invention according to claim 4 is
The thermoplastic resin (B) is a phenoxy resin, a polyether sulfone, or a polyimide resin.
3. The high dielectric constant composite material according to any one of 3 above. Claim 5
The invention described in (1) has (A) a thermosetting resin, (B) a thermoplastic resin, and (C) a dielectric filler as essential components, and the (B) thermoplastic resin is 10 to 50 relative to the total resin solid content. mass%
Is a high dielectric constant film. The invention according to claim 6 is the high dielectric constant film according to claim 5, wherein the storage elastic modulus determined by viscoelastic spectrum measurement is 1 to 5 GPa at room temperature. The invention according to claim 6 is a laminated sheet with a metal foil, wherein a metal foil is arranged on one side or both sides of the high dielectric constant film according to claim 5. The invention according to claim 7 is
(A) a thermosetting resin, (B) a thermoplastic resin, and (C) a dielectric filler as essential components, and (B) the thermoplastic resin is 10 to 50 mass% with respect to the total resin solid content. It is a printed wiring board having a passive element made of a characteristic high dielectric constant composite material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The high dielectric constant composite material of the present invention comprises (A) a thermosetting resin,
The thermoplastic resin (B) and the dielectric filler (C) are essential components, and the thermoplastic resin (B) is 10 relative to the total solid content of the resin.
It is characterized by being ˜50% by mass.

The thermosetting resin (A) used in the present invention is
Known materials can be used, for example, epoxy resin,
Phenolic resins, polyimide resins, melamine resins, cyanate resins, bismaleimides, addition polymerization products of bismaleimides and diamines, and the like, it is desirable to use those having excellent heat resistance during thermosetting, these alone or It can be used as a mixture, but is not limited thereto. Among these thermosetting resins, epoxy resins are preferable from the viewpoint of balance of heat resistance, processability, price and the like.

As the epoxy resin described in the present invention, known ones can be used. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type. Epoxy resin,
Hydrogenated compounds of epoxy compounds containing aromatic rings such as biphenyl type epoxy resin, biphenyl novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, alicyclic Formula epoxy resins, various derivatives of cyclohexene oxide, halogen-containing epoxy resins such as tetrabromobisphenol A type epoxy resins, and the like can be used, and these can be used alone or in combination.

Further, when an epoxy resin is used,
A known epoxy resin curing agent can be used. For example, polyphenols such as phenol novolac, dicyandiamide, diaminodiphenylmethane, amine-based curing agents such as diaminodiphenylsulfone, pyromellitic dianhydride, trimellitic anhydride, acid anhydride curing agents such as benzophenonetetracarboxylic acid or the like. A mixture etc. are mentioned. Above all, it is particularly preferable to use polyhydric phenols such as phenol novolac from the viewpoint of low water absorption.

The mixing ratio of the epoxy resin curing agent may be any ratio in combination with the epoxy resin, but the mixing ratio is usually determined so that the glass transition temperature becomes high. For example, when phenol novolac is used as the epoxy resin curing agent, it is preferable to mix them so that the epoxy equivalent and the hydroxyl equivalent are 1: 1.

As the thermoplastic resin (B) used in the present invention, known resins such as polyamide resin, polyimide resin, polyether ether ketone, polyether sulfone, polyphenylene ether resin, phenoxy resin, polysulfone, polyphenylene sulfide and polyolefin resin are used. However, a phenoxy resin, a polyether sulfone, or a polyimide resin is preferable in order to make the dielectric properties uniform in the high dielectric constant composite material. This is because the dielectric filler preferentially moves to a phase having low viscosity in the phase separation process of the thermosetting resin as the component (A) and the thermoplastic resin as the component (B), and thus the repeating structure is too large. This is because the dielectric properties within the layer vary.

The compounding ratio of the thermosetting resin and the thermoplastic resin of the high dielectric constant composite material described in the present invention should be 10 to 50% by mass of the total resin solid content in terms of the content of the thermoplastic resin. The reason for this is that if it is less than 10% by mass, the toughness effect of the thermoplastic resin cannot be obtained so much, and if it is 50% by mass or more, sufficient adhesion strength with the metal foil cannot be obtained.

A known curing catalyst may be added to the high dielectric constant composite material used in the present invention for the purpose of promoting the curing reaction. For example, when an epoxy resin is used as the thermosetting resin, the curing catalyst used is triphenylphosphine, tri-4-methylphenylphosphine, tri-4-methoxyphenylphosphine, tributylphosphine, trioctylphosphine, tri-2. -Organophosphine compounds such as cyanoethylphosphine and their tetraphenylborate salts; tributylamine, triethylamine, 1,8-diazabicyclo (5,4,
0) tertiary amines such as undecene-7 and triamylamine; quaternary ammonium salts such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide and triethylammonium tetraphenylborate; 2-
Examples thereof include imidazoles such as ethylimidazole and 2-ethyl-4-methylimidazole, but are not limited thereto. Of these, the use of organic phosphine compounds and imidazoles are particularly preferable for achieving the object of the present invention.

The mixing ratio of these curing catalysts can be added in any ratio so as to obtain a desired gel time. Usually, the gel time of high dielectric constant composite materials is 80 ° C to 2
It is preferable that the composition be blended for 1 to 15 minutes at each predetermined temperature of 50 ° C.

As the (C) dielectric filler used in the present invention, known ones can be used, but those having a relative dielectric constant of 50 or more are preferably used. Examples of such materials include titanium dioxide-based ceramics, barium titanate-based ceramics, calcium titanate-based ceramics, strontium titanate-based ceramics, lead zirconate-based ceramics, etc. These may be used alone or in combination. However, it is not particularly limited to these. Furthermore, in order to achieve a high dielectric constant, the same dielectric filler having two or more kinds of particle size distribution can be mixed and used.

The compounding ratio of the dielectric filler in the high dielectric constant composite material of the present invention is preferably such that the content of the dielectric filler is 30 to 90 mass% of the total solid content. The reason for this is that if the compounding ratio of the dielectric filler is higher than 90% by mass, the high dielectric constant composite material becomes brittle and the toughness of the thermoplastic resin is not imparted, and if the compounding ratio is lower than 30% by mass, a sufficient dielectric constant is obtained. Some things you can't get.

The average particle diameter of the dielectric filler is 0.01-5.
It is preferably 0 micron. The reason is 5
If the thickness exceeds 0 micron, the formability of the high dielectric constant film or laminated sheet with metal foil is poor, and in addition, it is not possible to form a thin high dielectric constant film or laminated sheet with metal foil. Will be low. On the other hand, if it is less than 0.01 μm, the viscosity of the composite material increases, and it becomes difficult to disperse the dielectric filler.

The solvent used in the present invention must be one that dissolves both the thermosetting resin and the thermoplastic resin and does not remain in the cured resin. When a phenoxy resin is used as the thermoplastic resin, toluene, cyclohexanone, dimethylformamide, methyl ethyl ketone, xylene, dioxane, tetrahydrofuran, acetone, butanol and the like can be mentioned.

Further, in the above high dielectric constant composite material, if necessary, additives such as a thermal polymerization inhibitor, a plasticizer, a leveling agent, a defoaming agent, an ultraviolet absorber and a flame retardant, and for coloring are added. It is possible to add pigments and the like.

The high dielectric constant composite material according to the present invention can be obtained, for example, by dissolving a thermosetting resin and a thermoplastic resin in the above solvent and a dielectric filler dispersed in a roll mill or a bead mill. You can

The high dielectric constant film using the high dielectric constant composite material of the present invention is obtained by coating the high dielectric constant composite material prepared as described above on a support such as polyethylene terephthalate (PET), and finally applying a solvent. If the high-dielectric-constant composite material itself has a film-forming ability by the method of drying and removing, it can be formed into a film by itself. Here, the storage elastic modulus obtained by measuring the viscoelastic spectrum of the film is 1 at room temperature.
It is preferably ˜5 GPa. If it is less than this value, the film will bend, and if it is more than this value, it becomes brittle.

Among the laminated plates with metal foil using the high dielectric constant composite material of the present invention, in which the metal foil is arranged only on one side, the high dielectric constant composite material prepared as described above is formed on the metal foil. It is obtained by coating and completely curing. For those with metal foil on both sides, high dielectric constant composite material is applied on the metal foil,
It can be obtained by bringing a metal foil into close contact with the semi-cured resin surface and completely curing it under pressure. Alternatively, using a known technique such as applying a high dielectric constant composite material prepared as described above onto a metal foil and completely curing it to form a metal foil on the high dielectric constant composite material surface by a plating method. It can be formed, but is not limited thereto.

Next, a printed wiring board using the high dielectric composite material of the present invention will be specifically described. The present invention can be formed from a high-dielectric-constant composite material, a high-dielectric-constant film, or a laminated sheet with a metal foil, and various methods such as a build-up method and a collective laminating method can be used for multilayering. Here, the collective stacking method will be described, but the manufacturing method and structure are not limited to this.

First, the insulating layers 3 and 5 on which the circuit is formed, the insulating layers 2 and 6 of the prepreg, the semi-cured high dielectric constant film 4 and the copper foils 1 and 7 formed by the above method are prepared. Next, arrange each layer as shown in Fig. 1, and 40 kgf / cm
^It heats at 170 degreeC for 2 hours under the pressure of ² , and a laminated body is obtained. The part where both sides of the high dielectric constant composite material are sandwiched by metal foils becomes a capacitor. This is drilled, the inner wall is plated and then sealed with a filler 12, and the through hole 11
To get Further, the copper wiring 13 is formed on the outermost layer by lithography and etching techniques, and the printed wiring board shown in FIG. 2 can be obtained.

[0026]

EXAMPLES Examples and comparative examples for producing a printed wiring board using the high dielectric constant composite material of the present invention will be described below.

[Example 1] First, 100.0 parts by mass of an epoxy resin (trade name EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), 63.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.),
Phenoxy resin (trade name Phenothote YP manufactured by Tohto Kasei Co., Ltd.
-50) 70.1 parts by mass was dissolved in a mixed solvent of cyclohexanone and DMF. To this solution, 545.0 parts by mass of barium titanate (trade name BT-05 manufactured by Sakai Chemical Industry Co., Ltd.) and a curing catalyst (trade name 2E4MZ manufactured by Tokyo Chemical Industry Co., Ltd.) were used.
After 2 parts by mass were dispersed with a kneading roll, stirring and defoaming were performed to obtain a high dielectric constant composite material.

The high dielectric constant composite material thus obtained was coated on a polyimide resin and dried in a drying oven at 80 ° C. for 1 hour, followed by heat curing treatment at 170 ° C. for 2 hours to obtain about 50 μm. A thick high dielectric layer was obtained. Electrodes with a diameter of 3 cm were formed on both surfaces of the high dielectric layer with a silver paste based on JIS standard C6481, and the relative dielectric constant at 1 MHz was measured with an LCR meter (4285A manufactured by HEWLETT PACKARD).

Next, a crack evaluation method will be described. The board for crack evaluation is the build-up wiring board technical standard Ver. The via stitch as shown in FIG. 3 was prepared in accordance with the crack resistance test of the high dielectric constant composite material in 2.0. About this board in a thermal shock tester −
40 ° C-R. T. The sample was exposed to a condition of up to 125 ° C. (15 minutes for each cycle), and after 500 cycles, the continuity was examined. When the continuity was obtained, no crack was generated, and when the continuity was not obtained, crack was generated. The storage elastic modulus of this high dielectric constant composite material (film) was 3.7 GPa,
It had flexibility.

Example 2 First, 100.0 parts by mass of an epoxy resin (trade name EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), 63.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.),
70.1 parts by mass of polyether sulfone (trade name Sumika Excel 5003P manufactured by Sumitomo Chemical Co., Ltd.) was dissolved in a mixed solvent of cyclohexanone and DMF. Add to this solution barium titanate (trade name BT-05, manufactured by Sakai Chemical Industry Co., Ltd.) 5
45.0 parts by mass and curing catalyst (trade name 2 manufactured by Tokyo Chemical Industry Co., Ltd.
E4MZ) (0.2 parts by mass) was dispersed by a kneading roll and then stirred and defoamed to obtain a high dielectric constant composite material.

Next, using the above high dielectric constant composite material, the relative dielectric constant was measured and cracks were evaluated in the same manner as in Example 1.

[Example 3] First, 100.0 parts by mass of an epoxy resin (trade name YDCN-703 manufactured by Tohto Kasei Co., Ltd.), 50.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.), and phenoxy resin (Toto Kasei Co., Ltd.) Product name Phenothote YP
-50) 64.5 parts by mass was dissolved in a mixed solvent of cyclohexanone and DMF. 501.4 parts by mass of barium titanate (trade name BT-05 manufactured by Sakai Chemical Industry Co., Ltd.) and a curing catalyst (trade name 2E4MZ manufactured by Tokyo Chemical Industry Co., Ltd.) were added to this solution.
After 2 parts by mass were dispersed with a kneading roll, stirring and defoaming were performed to obtain a high dielectric constant composite material.

Next, using the above high dielectric constant composite material, the relative dielectric constant was measured and cracks were evaluated in the same manner as in Example 1. The results obtained in Examples 1 to 3 are shown in Table 1.

[0034]

[Table 1]

[Comparative Example 1] First, 100.0 parts by mass of an epoxy resin (trade name EPPN-502H manufactured by Nippon Kayaku Co., Ltd.) and 63.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.) were mixed with cyclohexanone and DMF. It was dissolved in the solvent. Barium titanate (trade name BT manufactured by Sakai Chemical Industry Co., Ltd. was added to this solution.
-05) 381.5 parts by mass and 0.2 parts by mass of a curing catalyst (trade name: 2E4MZ manufactured by Tokyo Kasei Kogyo Co., Ltd.) were dispersed by a kneading roll, and then stirred and removed to obtain a high dielectric constant composite material.

Next, using the above high dielectric constant composite material, the relative dielectric constant was measured and cracks were evaluated in the same manner as in Example 1.

Comparative Example 2 First, 100.0 parts by mass of an epoxy resin (trade name YDCN-703 manufactured by Tohto Kasei Co., Ltd.) and 50.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.) were mixed solvent of cyclohexanone and DMF. Dissolved in. To this solution, barium titanate (trade name BT-produced by Sakai Chemical Industry Co., Ltd.
05) 351.0 parts by mass and 0.2 parts by mass of a curing catalyst (trade name: 2E4MZ manufactured by Tokyo Chemical Industry Co., Ltd.) were dispersed by a kneading roll, followed by stirring and defoaming to obtain a high dielectric constant composite material.

Next, using the above high dielectric constant composite material, a printed wiring board was prepared and evaluated in the same manner as in Example 1.

[Comparative Example 3] First, 100.0 parts by mass of an epoxy resin (trade name EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), 63.5 parts by mass of phenol novolac (manufactured by Nippon Kayaku Co., Ltd.),
Phenoxy resin (trade name Phenothote Y manufactured by Tohto Kasei Co., Ltd.
P-50) 70.1 parts by mass of cyclohexanone and DMF
Was dissolved in a mixed solvent of. 58.4 parts by mass of barium titanate (trade name BT-05 manufactured by Sakai Chemical Industry Co., Ltd.) and 0.2 parts of a curing catalyst (trade name 2E4MZ manufactured by Tokyo Chemical Industry Co., Ltd.) were added to this solution.
After mass parts were dispersed by a kneading roll, stirring and defoaming were performed to obtain a high dielectric constant composite material.

Next, using the above high dielectric constant composite material, the relative dielectric constant was measured and cracks were evaluated in the same manner as in Example 1.

Next, using the above high dielectric constant composite material, a printed wiring board was prepared and evaluated in the same manner as in Example 1. The results obtained in Comparative Examples 1 to 3 are shown in Table 2.

[0042]

[Table 2]

[0043]

Since the present invention has the above-mentioned constitution,
The thermoset material of the high dielectric constant composite material has excellent dielectric properties and is unlikely to crack even when subjected to a temperature history. Further, a high dielectric constant film, a laminated board with a metal foil, and a printed wiring board formed by using this have both toughness and adhesion to the metal foil.

[0044]

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing process of a printed wiring board according to the present invention.

FIG. 2 is an explanatory diagram of a printed wiring board according to the present invention.

[Explanation of symbols]

1 copper foil 2 Insulation layer (prepreg) 3 insulating layers 4 High dielectric constant film 5 insulating layers 6 Insulation layer (prepreg) 7 Copper foil 11 through holes 12 Filler 13 Copper wiring

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Claims (8)

[Claims] 1. A thermosetting resin (A), a thermoplastic resin (B) and a dielectric filler (C) as essential components, wherein the thermoplastic resin (B) is contained in an amount of 10 to 50 mass with respect to the total solid content of the resin. %, A high dielectric constant composite material. 2. The high dielectric constant composite material according to claim 1, wherein the dielectric filler (C) is 30 to 90 mass% with respect to the total solid content. 3. The high dielectric constant composite material according to claim 1, wherein the thermosetting resin (A) is an epoxy resin. 4. The (B) thermoplastic resin is a phenoxy resin,
Alternatively, the high dielectric constant composite material according to claim 1, which is a polyether sulfone or a polyimide resin. 5. A thermosetting resin (A), a thermoplastic resin (B) and a dielectric filler (C) as essential components, wherein the thermoplastic resin (B) is contained in an amount of 10 to 50 mass based on the total solid content of the resin. % High dielectric constant film. 6. The high dielectric constant film according to claim 5, wherein the storage elastic modulus determined by viscoelastic spectrum measurement is 1 to 5 GPa at room temperature. 7. A laminated sheet with a metal foil, wherein a metal foil is provided on one side or both sides of the high dielectric constant film according to claim 5. 8. A thermosetting resin (A), a thermoplastic resin (B), and a dielectric filler (C) as essential components, wherein the thermoplastic resin (B) is contained in an amount of 10 to 50 mass with respect to the total solid content of the resin. %, A printed wiring board having a passive element made of a high dielectric constant composite material.