JPH0583166B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a capacitor useful in electronic circuits and the like. [Prior Art] Capacitors used in electronic circuits include, for example, capacitors obtained by etching a flexible plate made by laminating metal foil on polyethylene tereftate (hereinafter referred to as "PET") film, and copper capacitors. Examples include capacitors obtained by etching a layer-formed ceramic plate and capacitors obtained by etching a copper-layer-formed mica plate. [Problem to be solved by the invention] When a PET flexible film is used as a dielectric of a capacitor, its relative permittivity is low;
There are problems such as insufficient capacitance of the capacitor, low Q value, and lack of soldering heat resistance. When a thin ceramic plate is used as the dielectric material of a capacitor, there are problems such as the capacitance of the capacitor varies due to the low thickness precision, and it is extremely susceptible to cracking, resulting in low yield and high cost. When a mica plate is used as a dielectric material in a capacitor, there is a problem in that the quality of the capacitor is uneven because mica is a natural product. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inexpensive and high-quality capacitor. [Means for Solving the Problems] In order to solve the above problems, the capacitor of the present invention uses polyphenylene containing the following components (a) and (b) in addition to polyphenylene oxide as a dielectric material. A cured product obtained from at least one of a film made of an oxide-based resin composition and a prepreg made by impregnating a base material with the resin composition is used, and metal foils serving as electrodes are placed on both sides of the cured product. (a) At least one of a crosslinkable polymer and a crosslinkable monomer. (b) An inorganic filler with a dielectric constant of 10 or more that has been subjected to calcination. [Function] In the capacitor of the present invention, since the dielectric material has a high dielectric constant, the capacitance can be increased, and the tan δ value is low, so the Q value is large. Since the dielectric is formed by curing a polyphenylene oxide resin composition,
It has soldering heat resistance and moderate flexibility, so it is difficult to break even if it is thin. Furthermore, by changing the amount and/or type of component (b) added to the polyphenylene oxide resin composition, the dielectric constant of the dielectric can be adjusted as desired, and thereby the capacitance can be controlled. [Example] The polyphenylene oxide resin composition used in the present invention naturally contains polyphenylene oxide, and in addition to this, it also contains at least the above components (a) and (b). Polyphenylene oxide (also referred to as polyphenylene ether) used in this invention.Hereinafter,
``PPO'') is, for example, the following general formula:

[Here, R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and each R may be the same or different. ]

An example thereof is poly(2,6-dimethyl-1,4-phenylene oxide). Such PPO can be synthesized, for example, by the method disclosed in USP 4,059,568. For example, poly(2,6-dimethyl-1,4-phenylene oxide) is obtained by subjecting 2,6-xylenol to an oxidative coupling reaction with an oxygen-containing gas and methanol in the presence of a catalyst. , but is not limited to this method. Here, as a catalyst, a copper() compound, N,N'-di-tert
- Contains butylethylenediamine, butyldimethylamine and hydrogen bromide. Based on methanol, add 2 to 15% by weight of water to the reaction mixture system, so that the total amount of methanol and water is 5 to 25%.
It is used so that it becomes a polymerization solvent. For example, the weight average molecular weight (Mw) is 50000, the molecular weight distribution Mw/Mn=4.2 (Mn
(number average molecular weight) is preferably used. PPO is a resin with a low dielectric constant and low dielectric loss, so a resin composition with any dielectric constant can be made by mixing it with an inorganic filler with a higher dielectric constant. A dielectric material having an arbitrary dielectric constant can be made using this resin composition. Additionally, PPO is inexpensive. By crosslinking (curing) component (a),
It is used to improve heat resistance etc. without impairing the properties of PPO. The crosslinkable polymer and the crosslinkable monomer may be used alone or in combination, but
Using them together is more effective in improving characteristics. Examples of crosslinkable polymers include, but are not limited to, 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (malein-modified, acrylic-modified, epoxy-modified ), rubbers, etc., each alone or in combination
Used in conjunction with two or more. The polymer state may be an elastomer or a rubber, but a high molecular weight rubber state is particularly preferred since it improves film forming properties. When forming a PPO-based resin composition into a film by the casting method described below, from the viewpoint of improving film-forming properties, it is preferable to use polystyrene within a range that does not impede achievement of the objectives of the present invention. Note that polystyrene with a high molecular weight is desirable because it improves film-forming properties. Examples of crosslinkable monomers include ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates,
Acrylates such as melamine acrylates, alkyd acrylates, silicone acrylates, polyfunctional monomers such as triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, vinyltoluene, ethylvinylbenzene, styrene , monofunctional monomers such as paramethylstyrene, and polyfunctional epoxies, each of which may be used alone or in combination of two or more, but is not particularly limited to these. As the crosslinkable monomer, it is preferable to use triallyl cyanurate and/or triallyl isocyanurate because they have good compatibility with PPO and are preferable in terms of film formability, crosslinkability, heat resistance, and dielectric properties. Triallyl cyanurate and triallyl isocyanurate are chemically structurally isomers and have almost the same film-forming properties, compatibility, solubility, reactivity, etc.; Can be used individually or both. Component (b) is used to increase the dielectric constant of the dielectric material made from the film and/or prepreg of the PPO resin composition to an arbitrarily high value. Inorganic fillers include aluminum oxide, silicon carbon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ),
Glass fiber, glass chip, barium titanate (BaTiO ₃ ), lead titanate (PbTiO ₃ ), strontium titanate (SrTiO ₃ ), calcium titanate (CaTiO ₃ ), magnesium titanate (MgTiO ₃ ),
Barium zirconate (BaZrO ₃ ), lead zirconate (PbZrO ₃ ), K ₂ O−PbO−SiO ₂ glass, and
Examples include sintered bodies of lead titanate and lead zirconate, each of which may be used alone or in combination of two or more, but is not limited thereto. In addition to the above-mentioned glass, a solid solution may also be used. In order to obtain a PPO resin composition with an arbitrary dielectric constant (permittivity), as an inorganic filler,
An inorganic filler having as large a dielectric constant as possible is preferred. Therefore, it is necessary that the relative dielectric constant of the inorganic filler is 10 or more. The inorganic filler with a dielectric constant of 10 or more is not particularly limited, but for example, titanium dioxide (TiO ₂ )
ceramic, barium titanate (BaTiO ₃ ) ceramic, lead titanate (PbTiO 3 ) ceramic, strontium titanate (SrTiO ₃ ) ceramic, calcium titanate (CaTiO _{3 )} ceramic, bismuth titanate (BiTiO ₃ or
Examples include Bi ₄ Ti ₃ O ₁₂ ) ceramic, magnesium titanate (MgTiO ₃ ) ceramic, and lead zirconate (PbZrO ₃ ) ceramic. These may be used alone or in combination of two or more. Furthermore, at least two of these ceramics may be mixed, fired, and pulverized. As an inorganic filler,
Each of these ceramics (fired ceramic raw materials singly or as a mixture of two or more), a mixture of at least two of these ceramics,
Ceramics that have undergone firing, such as those obtained by mixing and firing at least two types of ceramics (hereinafter,
It is necessary to use these (all referred to as "ceramics"). When the inorganic filler is fired, hydrates, hydroxides, etc. are removed, and as a result, the dielectric constant of the inorganic filler becomes stable.
This is because the affinity with the resin is improved and the heat resistance is improved. In order to stabilize the dielectric constant, it is preferable to keep the firing (or sintering) conditions constant. In addition, the titanium dioxide ceramic is a system containing only TiO ₂ or a system containing TiO ₂ and a small amount of other additives, and is the main component.
It maintains the crystal structure of TiO ₂ .
The same applies to other types of ceramics. Titanium dioxide is a substance represented by TiO ₂ and has various crystal structures, but among these, the rutile structure is used as a dielectric ceramic. The dielectric properties of inorganic fillers vary depending not only on their composition but also on firing (or sintering) and pulverization conditions (particle size, particle size distribution). Firing conditions vary depending on the type of inorganic filler, but are the same or almost the same as those for ceramic dielectrics using these fillers. It is preferable to carry out the firing without adding an organic binder as a powder, rather than to press the ceramic raw material powder to form a molded body and then perform the firing. This is because the sintered compact (sintered compact) is hard and difficult to crush, making it difficult to achieve the preferred average particle size and particle size distribution described below. Firing also includes treatments such as calcination when performing sintering. Table 1 shows examples of firing conditions for ceramics, but the conditions are not limited to these, nor are the types of ceramics to be fired.

[Table] Some of these fired ceramic dielectrics are very hard and cannot be easily pulverized, but since the characteristics vary depending on the particle size, it is preferable to grind them until they reach a certain particle size. In addition, the particle size of the inorganic filler is related to obtaining a uniform PPO-based resin composition. For this reason, inorganic fillers containing this
It is preferable that the size is such that it does not cause any inconvenience to a film made of a PPO resin composition, a prepreg made of a prepreg impregnated with this resin composition, etc., and it is preferable to use it as fine particles. The particle size is preferably about 50 μm or less, and if it is too small, handling may become difficult, so 0.1 to 20 μm (preferably 0.5 to 7 μm, more preferably 1.0 to 2.0 μm).
It is more preferable if it is within this range. The preferred particle size distribution of the inorganic filler is shown in Table 2, but is not limited thereto.

[Table] The inorganic filler may be used without any special surface treatment, but in order to improve the heat resistance, water absorption rate, etc. of the cured resin composition, it is preferable to perform a surface treatment. The surface treatment of the inorganic filler is preferably carried out using a common coupling agent such as silane type or titanium type. Aluminum oxide, titanium dioxide, silica (silicon dioxide), barium titanate, lead titanate,
By using the above-mentioned materials and other well-known dielectric materials with high relative permittivity as inorganic fillers, the relative permittivity of the cured product of the resulting PPO resin composition can be made relatively high, resulting in a high relative permittivity. It becomes possible to use it in applications that require a cured product with a dielectric constant. By adjusting the type and amount of the dielectric material, it is also possible to adjust the dielectric constant of the cured product of the PPO resin composition over a wide range. That is, the inorganic filler acts as a dielectric constant regulator. The upper limit of the blending ratio of the inorganic filler in the PPO resin composition is the point at which the cured product of the PPO resin composition begins to exhibit unfavorable tendencies such as becoming porous and losing strength. The blending ratio of the above raw materials is not particularly limited, but PPO10 to 95 parts by weight (more preferably 20 to 95 parts by weight)
90 parts by weight), component (a) 1 to 90 parts by weight, component (b)
1 to 200 parts by weight (preferably as a dielectric constant adjuster,
1 to 160 parts by weight). If the proportion of component (a) is less than the above range, adhesion may become insufficient, and if it exceeds the above range, PPO
characteristics may not appear. If the proportion of component (b) is less than the above range, the effect of adding the inorganic filler may not be apparent, and if it exceeds the above range, the above-mentioned unfavorable tendencies may occur. Adjustment of the dielectric constant using component (b) is performed, for example, as follows. That is, as confirmed by the inventors, 70 parts by weight of PPO, 15 parts by weight of styrene-butadiene copolymer, and triallyl isocyanurate.
The organic binder containing 14 parts by weight and 1 part by weight of dicumyl peroxide has a relative permittivity of 2.6 and a dielectric loss of 0.002 (23°C, 1MHz). Here, the dielectric constant of the composition containing 255 parts by weight of barium titanate to 100 parts by weight of this organic binder is 9.2.
The dielectric loss was 0.009 (23°C, 1MHz), and considering the dielectric constant of barium titanate of 2000, it can be seen that it is almost related to the blending ratio of barium titanate, that is, the blending ratio of the inorganic filler. Therefore, the compounding ratio of component (b) should be adjusted to the desired dielectric constant. In particular, when a flake-like material (inorganic material) is used as component (b), the dimensional stability, solvent resistance, warpage, etc. of the cured product of the PPO resin composition are further improved. Examples of the flaky inorganic filler include glass flakes and mica, each of which may be used alone or in combination of two or more, but is not limited thereto. For example, flat glass pieces such as micro glass flakes manufactured by Nippon Glass Fiber Co., Ltd.
Examples include glass flakes having a thickness of 2 to 3 μm and a particle size of 10 to 325 meshes, and/or fine mica particles such as Dimonite manufactured by Topy Industries, Ltd. of 5 to 100 meshes. From the viewpoint of electrical properties, mica is preferably muscovite, but is not particularly limited thereto. Note that the flaky inorganic filler preferably has a size of 80 mesh or less. If the size exceeds 80 meshes, when the PPO resin composition used in this invention is made into a solution as described below, the flaky inorganic filler will tend to settle and the storage stability in solution may deteriorate. There is. The flaky inorganic filler preferably has an average thickness of 3 μm or less and/or an aspect ratio of 100 or less. If the average thickness is larger than 3 μm and the aspect ratio is larger than 100, when this PPO resin composition is made into a film by the casting method as described below, the drying speed will be slow, resulting in poor work efficiency. , the physical properties of the film may deteriorate. In addition, in terms of the effect of improving the dimensional safety of molded products made of this PPO resin composition, the aspect ratio of the flaky inorganic filler is 10.
It is preferable that it is above. Further, the thickness of the flaky inorganic filler is preferably 1 μm or more. The flaky inorganic filler is used in this invention.
In the cured product of the PPO resin composition, it plays the role of a skeleton that connects the resins, improving the strength of the cured product, and since it is plate-shaped, it works to prevent the infiltration of chemicals such as solvents. Of course, it also contributes to dimensional safety. The blending ratio of the above raw materials is not particularly limited, but PPO10 to 95 parts by weight (more preferably 20 to 95 parts by weight)
80 parts by weight), 5 to 50 parts by weight (more preferably 5 to 45 parts by weight) of a crosslinkable polymer and/or 1 to 20 parts by weight of a crosslinkable monomer, and 1 to 80 parts by weight of a flaky inorganic filler. It is preferable to set the ratio to .
Further, although not particularly limited, it is preferable to use the crosslinkable polymer in a ratio of 20 parts by weight or less per 1 part by weight of the crosslinkable monomer. In addition, an initiator is usually used in PPO resin compositions. As the initiator, the following two types can be selected depending on whether the PPO resin composition is of an ultraviolet curing type or a thermosetting type, but the initiator is not limited to these. Examples of ultraviolet curing photoinitiators (that is, those that generate radicals when irradiated with ultraviolet light) include benzoin, benzyl,
Allyldiazonium fluoroborate, benzyl methyl ketal, 2,2-diethoxyacetophenone, benzoyl isobutyl ether, p-tert-
Butyl trichloroacetophenone, benzyl (o
-ethoxycarbonyl)-α-monoxime, biacetyl, acetophenone, benzophenone, Michler's ketone, tetramethylthiuram sulfide, azobisisobutyronitrile, and the like. Examples of thermosetting initiators (that is, those that generate radicals by heat) include dicumyl peroxide, tert-butyl mil peroxide, benzoyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl- 2,5-di-(tret-
butylperoxy)hexyne-3,2,5-dimethyl-2,5-di-(tert-butylperoxy)
peroxides such as hexane, α,α′-bis(tert-butylperoxy-m-isopropyl)benzene [also referred to as 1,4 (or 1,3)-bis(tert-butylperoxyisopropyl)benzene];
1-hydroxycyclohexyl phenyl edone,
2-Hydroxy-2-methyl-1-phenyl-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-
1-one, 2-chlorothioxanthone, methyl benzoylformate, 4,4-bisdimethylaminobenzophenone (Michler's ketone), benzoin methyl ether, methyl-o-benzoyl benzoate, α-acyloxime ester, NOF ( Examples include the Bisque Mill manufactured by Co., Ltd. Each of the initiators may be used alone or in combination of two or more. A UV initiator and a thermal initiator may be used in combination. The blending ratio of the initiator is 0.1 to 5 parts by weight (more preferably 0.1 to 5 parts by weight) relative to the above two types of blending ratio.
3 parts by weight). If the proportion of the initiator is below the above range, the PPO resin composition may not be sufficiently cured, and if it exceeds the above range, the physical properties after curing may be adversely affected. The raw materials according to the above formulation are usually dissolved and dispersed in a solvent (inorganic fillers usually do not dissolve) and mixed (solution mixing). In this case, PPO
It is preferable to use a 5 to 50% by weight solution of the resin composition (or a resin solid content in the range of 10 to 30% by weight based on the solvent). The solvent includes trichloroethylene, trichloroethane, chloroform,
Examples include halogenated hydrocarbons such as methylene chloride and chlorobenzene, aromatic hydrocarbons such as benzene, toluene, and xylene, acetone, and carbon tetrachloride, and trichlorethylene is particularly preferred, and these may be used alone or in combination of two or more. However, it is not limited to these. In addition,
Mixing may also be done by other methods. The PPO resin composition used in the present invention is a film made of the same, or a prepreg obtained by impregnating a base material with the PPO resin composition. If one or both of these are used in a desired number, handling is good and it becomes easy to form a dielectric with a desired thickness. A film made of a PPO resin composition can be produced by, for example, dissolving the raw materials in a solvent as described above, mixing them, casting or coating them on an appropriate object to form a thin layer, and then drying to remove the solvent. can be obtained by (casting method). According to this casting method, a film of a PPO resin composition can be produced at low temperatures without using the costly calendar method.
The film of the PPO resin composition may be made by a method other than the casting method. To describe the casting method in detail, a solution is prepared by dissolving the above PPO resin composition or its raw material in the above solvent at a ratio of, for example, 5 to 50% by weight (inorganic fillers usually do not dissolve). is casted (or coated) onto a mirror-treated iron plate or carrier film for casting to a thickness of, for example, 5 to 700 (preferably 5 to 500) μm, thoroughly dried, and then coated with a solvent. A film is obtained by removing the . Note that film here refers to sheet,
Including what is called a film, tape, etc., there are no particular limitations on the extent and length of the surface perpendicular to the thickness direction, and the thickness can also be set in various ways depending on the application. The above-mentioned carrier film for casting is not particularly limited, but it is preferably insoluble in the above-mentioned solvents, such as PET film, polyethylene film, polypropylene film, polyester film, polyimide film, etc., and has been subjected to mold release treatment. is preferred. The solvent of the PPO resin composition solution cast (or coated) on a carrier film for casting is removed by air drying and/or drying with hot air. The upper limit of the set temperature for drying is preferably lower than the boiling point of the solvent or lower than the heat-resistant temperature of the carrier film for casting (when drying is performed on the carrier film for casting); The lower limit is determined by drying time, processability, etc.
For example, using trichlorethylene as a solvent,
When a PET film is used as a carrier film for casting, the temperature range is preferably from room temperature to 80°C, and if the temperature is raised within this range, the drying time can be shortened. In addition, the film of the PPO resin composition produced in this way is sufficiently dried at a temperature lower than the decomposition temperature of the initiator blended and higher than the boiling point of the solvent used to eliminate residual solvent. . By performing thermal crosslinking using radical initiators, photocrosslinking, crosslinking using radiation, etc., it is possible to further improve tensile strength, impact strength, bursting strength, heat resistance, etc. can. The prepreg may be produced by any method, but generally, it can be produced by the following method. In other words, the PPO resin composition or its raw material,
For example, by completely dissolving 5 to 50% by weight of the above solvent (inorganic fillers usually do not dissolve), and dipping the base material in this solution (dipping), the base material can be coated with these materials. Impregnate and adhere PPO resin composition. In this case, the solvent may be simply removed by drying or the like, or it may be semi-cured to bring it to the B stage. The content of the PPO resin composition in the prepreg thus produced is not particularly limited, but is preferably 30 to 80% by weight based on the weight of the entire prepreg. Base materials include cloth-like materials that can be impregnated with resin such as glass cloth, aramid cloth, polyester cloth, and nylon cloth, pine-like materials made of these materials and/or fibrous materials such as nonwoven fabrics, and paper such as kraft paper and linter paper. are used, but are not limited to these. If the prepreg is produced in this way, it is not necessary to melt the resin, so it can be easily carried out at a relatively low temperature. In this invention, either one of the film of the PPO resin composition and the prepreg impregnated with the PPO resin composition is used, or
Use two or more sheets stacked together. Alternatively, one or more of both may be stacked in a desired number of layers. Metal foils are placed on both sides of the sheet, and then pressed, heated, and cured to obtain a metal foil-clad board or a metal foil-clad laminate. The heating at this time causes a crosslinking reaction by the radical initiator, so that curing occurs. The crosslinking reaction may be carried out by ultraviolet irradiation or the like. When thermal crosslinking and photocrosslinking are not performed, crosslinking by radiation irradiation may be performed. Furthermore, after thermal crosslinking and photocrosslinking, crosslinking by radiation irradiation may be performed. Pressure is applied to join films together, between films and prepregs, between prepregs, between metal foils and films, between metal foils and prepregs, and for adjusting the thickness of metal foil-clad boards and metal foil-clad laminated boards, so the conditions for applying pressure are as follows: Selected as needed. In addition, when crosslinking a PPO resin composition by heating, such as by heating it in a dryer, the crosslinking reaction depends on the reaction temperature of the initiator used, so the heating temperature may vary depending on the type of initiator. It is a good idea to choose. The heating time may also be selected depending on the type of initiator, etc. For example, the temperature is 150 to 300°C and the time is about 10 to 60 minutes. In the case of heat-pressing, a pressure of about 50 kg/cm ² is selected, for example. The film and/or the prepreg may be cured in advance, or a predetermined number of sheets may be heated and laminated, metal foils may be superimposed on both sides of the film and/or the prepreg may be heated and pressed again. By etching the metal foil of the obtained metal foil clad plate or metal foil laminate in a desired pattern, a printed circuit board or printed circuit board having electrostatic capacity can be obtained. This printed circuit board or printed circuit board is one embodiment of the capacitor of the present invention. The capacitor may be a laminated plate made by alternately stacking a large number of metal foils and dielectrics. Capacitors can also be obtained by dividing the metal foil-clad plate or metal foil-clad laminate into desired sizes. Although FIGS. 1 to 3 each represent one embodiment of the capacitor of the present invention, the present invention is not limited thereto. Capacitor 3 shown in Figure 1
In this case, electrodes 2, 2 are arranged on both sides of a single layer of dielectric material 1. The capacitor 13 shown in FIG.
At least one of PPO-based resin composition films and prepregs and metal foil are alternately stacked in large numbers to increase the opposing area of the electrodes 2, 2 facing each other with the dielectric 1 in between. Since the film and the prepreg have flexibility, the capacitor 23 may be formed by winding at least one of the film and the prepreg and a metal foil overlapping each other, as shown in FIG. 1 is a dielectric, and 2 is an electrode. The metal foil used is, for example, copper foil, aluminum foil, etc., but is not limited to these. Next, specific examples and comparative examples will be described, but the present invention is not limited to the examples. Example 1 40 g of polyphenylene oxide, 40 g of styrene butadiene copolymer, 120 g of triallylisocyanurate, 2,5 -dimethyl-2,5-
6 g of di-(tert-butylperoxy)hexyne-3 (Perhexine 25B, manufactured by NOF Corporation) was added and stirred thoroughly until a homogeneous solution was obtained. Next, 290 g of barium titanate (BaTiO ₃ ) ceramic powder was added and further stirred to uniformly disperse and defoam. A glass cloth (100 g/cm ² ) was immersed in the resulting PPO resin composition solution to be impregnated with the solution, taken out, and dried at 80° C. for about 5 minutes.
Got prepreg. Copper foil (thickness: 18 μm) was placed on both sides of this prepreg, and molded using a molding press at 195° C. and 10 kg/cm ² to obtain a copper-clad board. The thickness of the dielectric (insulating layer) was 0.107 mm. After etching this copper clad plate and cutting it,
Capacitors as shown in Figures a and b were obtained. In this capacitor 33, the dielectric 1 was 6 mm x 6 mm, and the electrode 2 was 5 mm x 5 mm. On the other hand, a capacitor was produced in the same manner as above except that the prepreg was laminated so that the thickness of the capacitor was 0.6 mm, and the following flexibility evaluation was used. The size of this capacitor was 100 mm x 100 mm. Examples 2 to 7 Capacitors were produced in the same manner as in Example 1, except that the PPO resin composition was formulated as shown in Table 3. Comparative Example 1 Copper foil coated with an isocyanate adhesive was placed on both sides of a PET film (thickness: 100 μm) and molded using a molding press at 130° C. and 20 kg/cm ² to obtain a copper-clad board. The copper clad plate thus obtained was processed in the same manner as in Example 1 to produce a capacitor. Example 8 Into the reactor equipped with a pressure reduction device in step 2, 100 g of polyphenylene oxide, 40 g of styrene-butadiene copolymer (Asahi Kasei Corporation: Solprene T406), and 60 g of triallyl isocyanurate (Nippon Kasei Corporation: TAIC) were added.
g, 3 g of 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3 (Perhexine 25B, Nippon Oil & Fats Co., Ltd.) was added, and trichlorethylene (Toagosei Chemical Co., Ltd.: Trichlene) was added. )
800 g was added and stirred thoroughly until a homogeneous solution was obtained. Thereafter, 290 g of barium titanate (BaTiO ₃ ) ceramic powder was added and further stirred to uniformly disperse and defoam. The obtained PPO resin composition solution was coated onto a PET film using a coating machine to a thickness of 370 μm. After drying this at 60°C for about 4 minutes, the formed film was released from the PET film and dried at 110°C for an additional 10 minutes to completely remove trichlorethylene.
A film made of a PPO resin composition was obtained. The thickness of this film was approximately 100 μm. Copper foil (thickness: 18 μm) was placed on both sides of this film, and it was molded using a molding press at 195° C. and 30 kg/cm ² to obtain a copper-clad board. This copper-clad plate was processed in the same manner as in Example 1 to produce a capacitor. Examples 9 to 14 Capacitors were produced in the same manner as in Example 8, except that the PPO resin composition was formulated as shown in Table 4. Comparative Example 2 Fuji Titanium Co., Ltd.'s capacitor ceramic (N-
3300) was used as the dielectric. It was not possible to make a 100 μm thick ceramic board.
Therefore, a capacitor was fabricated by forming a pattern on ceramic with a thickness of 500 μm. Regarding each capacitor in the example and comparative example,
The capacitance, Q value, solder heat resistance and flexibility were investigated as follows, and the results are shown in Tables 3 and 4. The capacitance and Q value were determined by impedance bridge. Solder heat resistance is determined by immersing a capacitor in solder at 260°C, visually observing the appearance of blistering or peeling of the copper foil and dielectric (insulator), and measuring the time from immersion until the blistering occurs. I looked it up. Flexibility was examined by dropping a 198g iron ball from a height of 20cm onto a 100mm x 100mm capacitor with a thickness of 0.6mm to see if it broke. ○ means no destruction.

[Table] *1: Styrene-butadiene copolymer *2: Triallylisocyanurate *3: 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3
*4: A...BaTiO ₃ -based ceramic B...PbZrO ₃ -based ceramic
C...PbTiO ₃ -based ceramic D...BaZrO ₃ -based ceramic
E...TiO ₂ series ceramic F...Ba ₄ Ti ₃ O ₁₂ series ceramic
G…〓TiO ₂ 〓700g＋〓BaTiO ₃ 〓150g＋〓SrTiO
_3. Powder obtained by mixing 150g, baking, and pulverizing.

〔Effect of the invention〕

The capacitor of this invention is PPO as mentioned above.
A cured product obtained from at least one of a film and a prepreg of a based resin composition is used as a dielectric, and metal foils serving as electrodes are arranged on both sides of the dielectric, resulting in low cost and high quality.

[Brief explanation of the drawing]

1, 2 and 3 are respectively perspective views of one embodiment of the capacitor of the present invention, FIG. 4a is a plan view of the capacitor used for performance evaluation in the embodiment, and FIG. 4b is a side sectional view thereof. 1... Dielectric, 2... Electrode, 3, 13, 23,
33... Capacitor.

Claims (1)

[Claims] 1. A capacitor in which metal foil is arranged on both sides of a sheet-like dielectric, the dielectric containing at least the following components (a) and (b) in addition to polyphenylene oxide. A capacitor characterized in that it is a cured product obtained from at least one of a film made of a polyphenylene oxide resin composition and a prepreg formed by impregnating a base material with the resin composition. (a) At least one of a crosslinkable polymer and a crosslinkable monomer. (b) An inorganic filler with a dielectric constant of 10 or more that has been subjected to calcination.