JP5912583B2 - Dielectric ceramic material and method for producing perovskite type complex oxide coarse particles used therefor - Google Patents

Description

  The present invention relates to a dielectric ceramic material useful as an inorganic filler for a composite dielectric and a method for producing perovskite-type composite oxide coarse particles used therefor.

In order to reduce the size, thickness, and density of electronic devices, multilayer printed wiring boards have come to be used frequently. This multilayer printed wiring board can cope with further downsizing, thinning, and high density of electronic equipment by providing a layer made of a high dielectric constant material on the inner layer or surface layer to improve the mounting density.
Conventionally, as a high dielectric constant material, a ceramic sintered body obtained by firing a ceramic powder and then firing the ceramic powder is used. Therefore, the dimensions and shape of the material are limited by the forming method. Further, since the sintered body is high in hardness and brittle, it is difficult to freely process it, and it is extremely difficult to obtain an arbitrary shape or a complicated shape.

For this reason, a composite dielectric material in which an inorganic filler having a high dielectric constant is dispersed in a resin is attracting attention because of its excellent workability (see, for example, Patent Document 1).
In Patent Document 1, since porous perovskite complex oxide particles having a relatively large particle diameter are used, there is no problem in handling properties, but the amount that can be filled in the resin is about 30% by volume at most. In addition, there is a problem that the dielectric constant of the obtained composite dielectric is low.

  On the other hand, Patent Document 2 discloses a technique of filling a thermosetting resin with 65 to 90 volume% of a dielectric filler. However, in Patent Document 2, since the dielectric filler is highly filled, there is a concern that the mechanical characteristics and the electrical insulation are deteriorated, and the dielectric constant is low instead of the high filling rate. . Further, the higher the dielectric filler is filled, the higher the density of the composite dielectric, so that the composite dielectric disclosed in Patent Document 2 is not suitable for applications requiring further weight reduction. Furthermore, since the dielectric filler is generally more expensive than the resin, there is a problem that the higher the dielectric filler is filled, the higher the product cost is.

JP-A-5-94717 JP 2001-233669 A

  Therefore, the present invention provides a dielectric ceramic material which can be filled at least 30% by volume in the resin constituting the composite dielectric and can increase the dielectric constant of the composite dielectric without filling higher than before. The purpose is to do. Another object of the present invention is to provide an industrially advantageous method for producing perovskite-type composite oxide coarse particles used for the dielectric ceramic material.

As a result of extensive research, the present inventor has found that a dielectric ceramic material combining two types of perovskite complex oxide particles having a specific average particle diameter and a BET specific surface area can solve the above-mentioned problems. The invention has been completed.
That is, the dielectric ceramic material according to the present invention is a perovskite (ABO ₃ ) type composite oxide having an average particle size of 8 μm to 50 μm and a BET specific surface area of 0.3 m ² / g to 1.0 m ² / g. It consists of coarse particles and perovskite (ABO ₃ ) type complex oxide fine particles having an average particle diameter of 0.7 μm to 3 μm and a BET specific surface area of 0.6 m ² / g to 3 m ² / g.

The method for producing perovskite-type composite oxide coarse particles according to the present invention is selected from a carbonate containing at least one element selected from the group consisting of Ba, Ca, Mg and Sr, and a group consisting of Ti and Zr. A step of preparing a slurry containing an oxide containing at least one element and a dispersion medium, a step of drying the slurry by a spray drying method to obtain a granulated powder, and a firing temperature of the granulated powder of 1000 ° C. and adjusted in the range of 1400 ° C. inclusive, and has a step of BET specific surface area to obtain a 0.3 m ² / g or more 1.0 m ² / g or less is fired body.

  According to the dielectric ceramic material of the present invention, at least 30% by volume can be filled in the resin constituting the composite dielectric, and the dielectric constant of the composite dielectric can be increased without filling higher than before. Also, according to the method for producing perovskite complex oxide coarse particles of the present invention, the perovskite complex oxide coarse particles used for the dielectric ceramic material can be advantageously produced industrially.

3 is an electron micrograph of perovskite complex oxide coarse particles obtained in Production Example 1. FIG.

The average dielectric ceramic material according to the present invention, BET specific surface area average particle diameter in 8μm~50μm is 0.3m ² /g~1.0m ² / g perovskites (ABO ₃₎ type composite oxide coarse particles particle size is composed of the BET specific surface area of 0.6m ² / g~3m ² / g perovskites (ABO ₃₎ type composite oxide fine particles 0.7Myuemu～3myuemu.
If the average particle size of the perovskite-type composite oxide coarse particles is less than 8 μm, it is necessary to perform strong crushing due to the fusion of the particles during firing, resulting in reduced crystallinity and generation of fine particles. On the other hand, when the average particle diameter is more than 50 μm, the maximum diameter exceeds 100 μm, and the degree of freedom regarding the thickness is lost in the composite with the resin, and the use is greatly limited. Preferably, the average particle diameter of the perovskite complex oxide coarse particles is 10 μm to 30 μm. Furthermore, when the BET specific surface area of the perovskite complex oxide coarse particles is less than 0.3 m ² / g, it is difficult to efficiently express the dielectric constant at the time of resin compounding, while the BET specific surface area is 1.0 m ^2. If it is more than / g, particle collapse or fine particle generation at the time of crushing occurs, or difficulty in dispersion into the resin itself. Preferably, BET specific surface area of the perovskite-type composite oxide coarse particles is 0.4m ² /g~0.7m ² / g.
Further, when the average particle size of the perovskite type complex oxide fine particles is less than 0.7 μm, the crystallinity of the particles themselves is low, which is disadvantageous for improving the dielectric constant, while the average particle size is more than 3 μm. It exists between coarse particles and hinders improvement in dispersibility. Preferably, the average particle size of the perovskite complex oxide fine particles is 1 μm to 2 μm. Furthermore, if the BET specific surface area of the perovskite-type composite oxide fine particles is less than 0.6 m ² / g, it is difficult to improve the dielectric constant efficiently at the time of resin composite, while the BET specific surface area exceeds 3 m ² / g. When it exists, the dispersibility to resin will worsen and it will become easy to produce malfunctions, such as reducing the mechanical strength of a composite. Preferably, BET specific surface area of the perovskite type composite oxide particles is 0.8m ² / g~2m ² / g.
The average particle diameter in the present invention is a value determined by a laser light scattering method.

  In the dielectric ceramic material according to the present invention, the blending ratio of the perovskite complex oxide coarse particles is preferably 10% by weight to 70% by weight and the blending ratio of the perovskite complex oxide fine particles is preferably 30% by weight to 90% by weight. More preferably, the blending ratio of the perovskite complex oxide coarse particles is 30 wt% to 60 wt%, and the blending ratio of the perovskite complex oxide fine particles is 40 wt% to 70 wt%. When the blending ratio of the perovskite complex oxide coarse particles and the perovskite complex oxide fine particles is within the above range, the composite dielectric has excellent dispersibility when combined with a resin, high strength, and excellent dielectric properties. Can be obtained.

The composition of the perovskite complex oxide is not particularly limited, but the A site element is at least one selected from the group consisting of Ba, Ca, Mg and Sr, and the B site element is Ti and It is preferably at least one selected from the group consisting of Zr. Specific preferred compositions are exemplified by BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , Ba _x Ca _1-x TiO ₃ (where x is 0 <x <1), Ba _x Sr _1-x ZrO ₃ (wherein , X is 0 <x <1), BaTi _x Zr _1-x O ₃ (where x is 0 <x <1), Ba _x Ca _1-x Ti _y Zr _1-y O ₃ (where x is 0 <x <1, y is _{0 <y <1), Ba} 1-x-y Ca x Mg y Ti z Zr 1-z O 3 ( wherein, x is 0 <x <1, y is 0 < Examples of y <1, z include 0 <z <1, 0 <x + y <1). These perovskite complex oxides may be used alone or in combination of two or more.

  In the perovskite type complex oxide, the A / B ratio indicating the molar ratio between the A site element and the B site element is preferably 0.995 to 1.010, more preferably 0.997 to 1.005, most preferably It is in the range of 0.999 to 1.004. When the A / B ratio is within the above range, the dielectric constant of the composite dielectric filled with the dielectric ceramic material can be further increased.

  The particle shape of the perovskite complex oxide is preferably spherical from the viewpoint of excellent filling properties. In addition, as long as the particle shape is a shape that can be regarded as a sphere, it is not necessarily required to be a true sphere.

The production history of such a perovskite complex oxide is not particularly limited, and examples thereof include a coprecipitation method, a hydrolysis method, a hydrothermal synthesis method, a sol-gel method, a solid phase method, and an oxalate method. What is obtained by a normal method can be used.
Among these, it is desirable from the industrial viewpoint that the perovskite-type complex oxide coarse particles are produced using a solid phase method. A specific method for producing the perovskite-type composite oxide coarse particles is selected from the group consisting of carbonate containing at least one element selected from the group consisting of Ba, Ca, Mg and Sr, and the group consisting of Ti and Zr. A slurry containing an oxide containing at least one element and a dispersion medium may be prepared, the slurry may be dried by a spray drying method to obtain a granulated powder, and the granulated powder may be fired. By adjusting the firing temperature of the granulated powder in a range of 1000 ° C. to 1400 ° ^C., to obtain a perovskite-type composite oxide coarse particles having a BET specific surface area of 0.3m ² /g~1.0m 2 / g it can.

Note that the slurry to be dried by the spray drying method is mixed and pulverized by a wet pulverization apparatus such as a media mill, so that a uniform mixed slurry in which each raw material is uniformly mixed can be obtained more easily. It is preferable from the viewpoint.
Further, the treatment by the media mill is performed so that the average particle size of the solid content in the slurry is 0.8 μm or less, preferably 0.1 μm to 0.6 μm, and the maximum particle size is 3 μm or less. From the viewpoint of easily obtaining a perovskite-type composite oxide coarse particle having an average particle diameter and a BET specific surface area in the above range while controlling the state of the voids, and having excellent dielectric properties. .
As the media mill, a bead mill, a ball mill, a paint shaker, an attritor, a sand mill, or the like can be used. It is particularly preferable to use a bead mill. In that case, the operating conditions and the type and size of the beads may be appropriately selected according to the size and processing amount of the apparatus and the type of raw material to be used.

  Further, the drying by the spray drying method is such that the drying temperature is 100 ° C. to 130 ° C., preferably 105 ° C. to 120 ° C., and the average particle diameter of the granulated powder is 10 μm to 60 μm, preferably 15 μm to 40 μm. Is preferably performed from the viewpoint of controlling the particle diameter of the target perovskite complex oxide coarse particles.

  The reason for setting the firing temperature in the above range is that if the temperature is less than 1000 ° C., the firing cannot proceed to reach the target specific surface area, whereas if it exceeds 1400 ° C., specialization of the equipment for firing is required. It is. The firing time is usually 5 hours to 30 hours, preferably 10 hours to 20 hours. The firing atmosphere is not particularly limited and may be either air or an inert gas atmosphere.

Moreover, you may make the slurry used by the said manufacturing method contain a barium titanate precursor. By containing the barium titanate precursor in the slurry, it is possible to simplify the composition control and obtain a product with extremely small variation in characteristics. The barium titanate precursor is formed by reacting TiCl ₄ , BaCl ₂ and oxalic acid in an aqueous solution to form a precipitate of BaTiO (C ₂ O ₄ ) ₂ .4H ₂ O (barium titanyl oxalate). The resulting precipitate is obtained by drying or deacidifying. In addition, this production method has an advantage that perovskite-type composite oxide coarse particles can be obtained without using a sintering aid such as glass powder represented by boron silicon-based or bismuth-based. Although the sintering aid has the effect of lowering the sintering temperature, it lowers the chemical and environmental resistance of the resulting perovskite complex oxide coarse particles. Therefore, it is preferable that the perovskite complex oxide coarse particles do not contain a sintering aid.

  Perovskite-type composite oxide fine particles are preferably produced from the industrial viewpoint by using the oxalate method. In the oxalate method, it is necessary to sufficiently remove organic substances derived from oxalic acid by calcination. The firing temperature is usually 950 ° C to 1200 ° C, preferably 1050 ° C to 1150 ° C. The firing time is usually 5 hours to 30 hours, preferably 10 hours to 20 hours. The firing atmosphere is not particularly limited and may be either air or an inert gas atmosphere. In this production method, the firing may be performed as many times as desired, and the fired once may be pulverized and refired to make the powder characteristics uniform.

  The perovskite complex oxide obtained by the above-described production method may contain a subcomponent element-containing compound for the purpose of adjusting dielectric characteristics and temperature characteristics, if necessary. Examples of the subcomponent element-containing compound that can be used include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu rare earth elements. At least one selected from the group consisting of Ba, Li, Bi, Zn, Mn, Al, Si, Ca, Sr, Co, Ni, Cr, Fe, Mg, Ti, V, Nb, Mo, W and Sn Examples include compounds containing elements. These subcomponent element-containing compounds may be inorganic or organic, for example, oxides, hydroxides, chlorides, nitrates, oxalates, carboxylates, alkoxides and the like containing the above elements. Is mentioned. The perovskite complex oxide may contain a subcomponent element according to a conventional method, for example, adding a subcomponent element-containing compound to the perovskite complex oxide raw material powder.

  The dielectric ceramic material of the present invention can be suitably used as an inorganic filler for a composite dielectric composed of a polymer material such as a thermosetting resin or a thermoplastic resin and an inorganic filler. It is also applicable to uses such as agents.

Next, a composite dielectric using the dielectric ceramic material of the present invention as an inorganic filler will be described.
The composite dielectric according to the present invention can be filled with the above-described dielectric ceramic material in a polymer material described later, preferably 30% to 60% by volume, more preferably 40% to 55% by volume. If the dielectric ceramic material has a too low filling rate, a high dielectric constant cannot be obtained. On the other hand, if the filling rate is too high, there is a concern that the mechanical properties and the electrical insulation are deteriorated. However, the dielectric ceramic material of the present invention can achieve the same dielectric constant with a lower filling factor than that of Patent Document 2 (see Examples described later).

Examples of the polymer material that can be used in the present invention include a thermosetting resin, a thermoplastic resin, and a photosensitive resin.
Examples of thermosetting resins include epoxy resins, phenol resins, polyimide resins, melamine resins, cyanate resins, bismaleimides, addition polymers of bismaleimides and diamines, polyfunctional cyanate ester resins, and double resins. Well-known things, such as bond addition polyphenylene oxide resin, unsaturated polyester resin, polyvinyl benzyl ether resin, polybutadiene resin, and fumarate resin, are mentioned. These thermosetting resins may be used individually by 1 type, and may be used in combination of 2 or more type. Among these thermosetting resins, an epoxy resin and a polyvinyl benzyl ether resin are preferable from the balance of heat resistance, processability, price, and the like.

  The epoxy resin used in the present invention includes monomers, oligomers, and polymers in general having at least two epoxy groups in one molecule. For example, phenols including phenol novolac type epoxy resins and orthocresol novolac type epoxy resins, Phenols such as cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F and / or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene and aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde Epoxidized novolak resin obtained by condensing or co-condensing with an acidic catalyst, bisphenol A, bisphenol B, bisphenol F, bisphenol S, diglycidyl ether such as alkyl-substituted or unsubstituted biphenol, epoxidized adduct or polyaddition product of phenol and dicyclopentadiene or terpene, polybasic acid such as phthalic acid, dimer acid and epichlorohydrin Glycidyl ester type epoxy resin obtained by the reaction of glycidyl amine type epoxy resin obtained by the reaction of polyamine such as diaminodiphenylmethane and isocyanuric acid and epichlorohydrin, linear fat obtained by oxidizing the olefin bond with peracid such as peracetic acid Group epoxy resin, alicyclic epoxy resin, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

The epoxy resin curing agent, it is possible to use all known those in the art, in particular, ethylenediamine, trimethylenediamine, tetramethylenediamine, linear aliphatic diamines of C ₂ -C _20, such as hexamethylenediamine, Metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 4,4 ' -Amines such as diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1,5-diaminonaphthalene, metaxylylenediamine, paraxylylenediamine, 1,1-bis (4-aminophenyl) cyclohexane, dicyanodiamide Kind Benzol such as novolak type resin such as novolak resin, cresol novolak resin, tert-butylphenol novolak resin, nonylphenol novolak resin, resol type phenol resin, polyparaoxystyrene, phenol aralkyl resin, naphthol type aralkyl resin, etc. Examples thereof include phenol resins obtained by cocondensation of a phenol compound in which a hydrogen atom bonded to a ring, a naphthalene ring or other aromatic ring is substituted with a hydroxyl group, and a carbonyl compound, and acid anhydrides. These may be used individually by 1 type and may be used in combination of 2 or more type.
The compounding quantity of an epoxy resin hardening | curing agent becomes like this. Preferably it is 0.1-10 in an equivalent ratio with respect to an epoxy resin, More preferably, it is the range of 0.7-1.3.

  In the present invention, a known curing accelerator can be used for the purpose of accelerating the curing reaction of the epoxy resin. Examples of the curing accelerator include 1,8-diaza-bicyclo (5,4,0) undecene-7, tertiary amine compounds such as triethylenediamine and benzyldimethylamine, 2-methylimidazole, 2-ethyl-4- Examples thereof include imidazole compounds such as methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole, organic phosphine compounds such as triphenylphosphine and tributylphosphine, phosphonium salts and ammonium salts. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The polyvinyl benzyl ether resin used in the present invention is obtained from a polyvinyl benzyl ether compound. The polyvinyl benzyl ether compound is preferably a compound represented by the following general formula (1).

In formula (1), R ₁ represents a methyl group or an ethyl group. R ₂ represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group represented by R ₂ is an alkyl group, aralkyl group, aryl group or the like which may have a substituent. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aralkyl group include a benzyl group. Examples of the aryl group include a phenyl group. R ₃ represents a hydrogen atom or a vinylbenzyl group. The hydrogen atom of R ₃ is derived from the starting compound in the case of synthesizing the compound of general formula (1), and the curing reaction is carried out when the molar ratio of hydrogen atom to vinylbenzyl group is 60:40 to 0: 100. The composite dielectric of the present invention is preferable in that it can be sufficiently advanced and sufficient dielectric properties can be obtained. n shows the integer of 2-4.

  The polyvinyl benzyl ether compound may be used by polymerizing only it as a resin material, or may be used by copolymerizing with other monomers. Examples of the copolymerizable monomer include styrene, vinyl toluene, divinyl benzene, divinyl benzyl ether, allylphenol, allyloxybenzene, diallyl phthalate, acrylic acid ester, methacrylic acid ester, vinyl pyrrolidone, and modified products thereof. The mixing ratio of these monomers is 2% by mass to 50% by mass with respect to the polyvinyl benzyl ether compound.

Polymerization and curing of the polyvinyl benzyl ether compound can be performed by a known method. Curing can be done in the presence or absence of a curing agent. As the curing agent, for example, known radical polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, and t-butyl perbenzoate can be used. The usage-amount is 0 mass part-10 mass parts with respect to 100 mass parts of polyvinyl benzyl ether compounds. The curing temperature varies depending on whether or not the curing agent is used and the type of the curing agent, but is preferably 20 ° C. to 250 ° C., more preferably 50 ° C. to 250 ° C. in order to sufficiently cure.
Moreover, you may mix | blend hydroquinone, a benzoquinone, copper salt, etc. for adjustment of hardening.

  Examples of the thermoplastic resin include known ones such as (meth) acrylic resin, hydroxystyrene resin, novolac resin, polyester resin, polyimide resin, nylon resin, and polyetherimide resin.

  Examples of the photosensitive resin include known ones such as a photopolymerizable resin and a photocrosslinkable resin.

  Examples of the photopolymerizable resin used in the present invention include those containing an acrylic copolymer (photosensitive oligomer) having an ethylenically unsaturated group, a photopolymerizable compound (photosensitive monomer), and a photopolymerization initiator, epoxy. The thing containing resin and a photocationic polymerization initiator is mentioned. Photosensitive oligomers include those obtained by adding acrylic acid to an epoxy resin, those obtained by reacting them with an acid anhydride, and (meth) acrylic acid on a copolymer containing a (meth) acrylic monomer having a glycidyl group. Those obtained by reacting them with acid anhydride, those obtained by reacting glycidyl (meth) acrylate with a copolymer containing a (meth) acrylic monomer having a hydroxyl group, and those obtained by reacting acid anhydride with it. Examples include those obtained by reacting a copolymer containing maleic anhydride with a (meth) acrylic monomer having a hydroxyl group or a (meth) acrylic monomer having a glycidyl group. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Examples of the photopolymerizable compound (photosensitive monomer) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-vinylpyrrolidone, acryloylmorpholine, methoxypolyethylene glycol (meth) acrylate, and polyethylene. Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, N, N-dimethylacrylamide, phenoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, trimethylolpropane (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol hexa (meth) acrylate, tris (hydroxyethyl) isocyanurate di (meth) acrylate, tris (hydroxyethyl) Isocyanurate tri (meth) acrylate. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Examples of the photopolymerization initiator include benzoin and its alkyl ethers, benzophenones, acetophenones, anthraquinones, xanthones, thioxanthones, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type. In addition, these photoinitiators can be used together with well-known and usual photopolymerization accelerators, such as a benzoic acid type and a tertiary amine type. Examples of the cationic photopolymerization initiator include triphenylsulfonium hexafluoroantimonate, diphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, and iron aroma of Bronsted acid. Group compound salts (Ciba-Geigy Corporation, CG24-061) and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Although the epoxy resin undergoes ring-opening polymerization by the photocationic polymerization initiator, the photopolymerizability is more preferable because the reaction speed of the alicyclic epoxy resin is faster than that of a normal glycidyl ester epoxy resin. An alicyclic epoxy resin and a glycidyl ester epoxy resin can be used in combination. Examples of the alicyclic epoxy resin include vinylcyclohexene diepoxide, alicyclic diepoxy acetal, alicyclic diepoxy adipate, alicyclic diepoxycarboxylate, manufactured by Daicel Chemical Industries, Ltd., EHPE-3150, and the like. It is done. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Examples of the photocrosslinkable resin include water-soluble polymer dichromate-based, polyvinyl cinnamate (Kodak KPR), and cyclized rubber azide (Kodak KTFR). These may be used individually by 1 type and may be used in combination of 2 or more type.

  The dielectric constant of these photosensitive resins is generally as low as 2.5 to 4.0. Therefore, in order to increase the dielectric constant of the binder, a higher dielectric polymer (for example, SDP-E (ε: 15 <) of Sumitomo Chemical, cyanoresin of Shin-Etsu Chemical ( ε: 18 <)) and high dielectric liquid (for example, SDP-S (ε: 40 <) from Sumitomo Chemical) may be added.

  In the present invention, the polymer materials described above may be used alone or in combination of two or more.

  In addition, the composite dielectric of the present invention can contain other inorganic fillers in an addition amount that does not impair the effects of the present invention. Examples of other inorganic fillers include carbon fine powder such as acetylene black and ketjen black, graphite fine powder, silicon carbide and the like.

  Further, the composite dielectric of the present invention has a curing agent, glass powder, coupling agent, polymer additive, reactive diluent, polymerization inhibitor, leveling agent, wettability as long as the effects of the present invention are not impaired. Improving agent, surfactant, plasticizer, UV absorber, antioxidant, antistatic agent, inorganic filler, antifungal agent, humidity control agent, dye dissolving agent, buffering agent, chelating agent, flame retardant, silane cup A ring agent (integral blend method) or the like may be added. These additives may be used individually by 1 type, and may be used in combination of 2 or more type.

  The composite dielectric of the present invention can be produced by preparing a composite dielectric paste and performing an organic solvent removal, curing reaction or polymerization reaction. The composite dielectric paste contains a resin component, a dielectric ceramic material, additives that are added as necessary, and an organic solvent.

  The resin component contained in the composite dielectric paste is a polymerizable compound of a thermosetting resin, a polymer of a thermoplastic resin, and a polymerizable compound of a photosensitive resin. In addition, these resin components may be used individually by 1 type, and may be used in combination of 2 or more type.

  Here, the polymerizable compound indicates a compound having a polymerizable group, and includes, for example, a precursor polymer, a polymerizable oligomer, and a monomer before complete curing. Moreover, a polymer shows the compound which the polymerization reaction was completed substantially.

  The organic solvent added as necessary varies depending on the resin component used and is not particularly limited as long as it can dissolve the resin component. For example, N-methylpyrrolidone, dimethylformamide, ether, diethyl ether, tetrahydrofuran , Dioxane, ethyl alcohol ether of monoalcohol having linear or branched alkyl group having 1 to 6 carbon atoms, propylene glycol ether, butyl glycol ether, ketone, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, Cyclohexanone, ester, ethyl acetate, butyl acetate, ethylene glycol acetate, methoxypropyl acetate, methoxypropanol, other halogenated hydrocarbons, alicyclic hydrocarbons And an aromatic hydrocarbon and the like. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, hexane, heptane, cyclohexane, toluene, and dixylene are preferable.

  In the present invention, the composite dielectric paste is prepared to have a desired viscosity. The viscosity of the composite dielectric paste is usually 1,000 mPa · s to 1,000,000 mPa · s (25 ° C.), and preferably 10,000 mPa · s to 600 considering the applicability of the composite dielectric paste. 1,000 mPa · s (25 ° C.).

  The composite dielectric of the present invention can be processed and used as a film-shaped, bulk-shaped or predetermined-shaped molded body, and can be used particularly as a high-dielectric film having a thin film shape.

In order to manufacture a composite dielectric film using the composite dielectric material of the present invention, for example, it may be manufactured according to a conventionally known method of using a composite dielectric paste, and an example thereof is shown below.
After applying the composite dielectric paste onto the substrate, it can be formed into a film by drying. As the base material, for example, a plastic film having a surface subjected to a peeling treatment can be used. When applied onto a plastic film that has been subjected to a release treatment and formed into a film, it is generally preferable to use the substrate after peeling it from the film. Examples of the plastic film that can be used as the substrate include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, polyester film, polyimide film, aramid, kapton, and polymethylpentene. The thickness of the plastic film used as the substrate is preferably 1 μm to 100 μm, more preferably 1 μm to 40 μm. Moreover, as a mold release process performed on the substrate surface, a mold release process in which silicone, wax, fluororesin or the like is applied to the surface is preferably used.

  Alternatively, a metal foil may be used as the substrate, and a dielectric film may be formed on the metal foil. In such a case, the metal foil used as the base material can be used as the capacitor electrode.

  The method for applying the composite dielectric paste on the substrate is not particularly limited, and a general application method can be used. For example, it can apply | coat by the roller method, the spray method, the silk screen method, etc.

  Such a dielectric film can be heated and thermally cured after being incorporated into a substrate such as a printed circuit board. Further, when a photosensitive resin is used, patterning can be performed by selective exposure.

Further, for example, the composite dielectric of the present invention may be extruded and formed into a film by a calendar method or the like.
The extruded dielectric film may be molded so as to be extruded onto the substrate. Moreover, when using metal foil as a base material, foil, composite foil, etc. of these alloys other than foil made from copper, aluminum, brass, nickel, iron, etc. can be used as metal foil. The metal foil may be subjected to a surface roughening treatment or an adhesive application treatment as necessary.

  A dielectric film may be formed between the metal foils. In this case, after applying the composite dielectric paste on the metal foil, the metal foil is placed on the metal foil, and then dried with the composite dielectric paste sandwiched between the metal foils, so that the metal foil is sandwiched between the metal foils. You may form the dielectric film of the state. Alternatively, a dielectric film provided between the metal foils may be formed by extrusion so as to be sandwiched between the metal foils.

  The composite dielectric of the present invention may be used as a prepreg by forming a varnish using the organic solvent described above, then impregnating it with a cloth or a nonwoven fabric, and drying. The kind of cloth or nonwoven fabric that can be used is not particularly limited, and known ones can be used. Examples of the cloth include glass cloth, aramid cloth, carbon cloth, stretched porous polytetrafluoroethylene, and the like. Examples of the nonwoven fabric include an aramid nonwoven fabric and glass paper. The prepreg can be laminated on an electronic component such as a circuit board and then cured to introduce an insulating layer into the electronic component.

  Since the composite dielectric of the present invention has a high dielectric constant, it can be suitably used as a dielectric layer of electronic components, particularly electronic components such as printed circuit boards, semiconductor packages, capacitors, high frequency antennas, and inorganic EL.

  In order to produce a multilayer printed wiring board using the composite dielectric of the present invention, it can be produced by a method known in the technical field (for example, JP 2003-192768 A, JP 2005-29700 A). No., JP 2002-226816 A, JP 2003-327827, etc.). In addition, the example shown below is an example at the time of using a thermosetting resin as a polymer material of a composite dielectric.

  The composite dielectric of the present invention is used as the dielectric film described above, and the circuit board is pressed and heated on the resin surface of the dielectric film, or laminated using a vacuum laminator. After lamination, a metal foil is further laminated on the resin layer exposed by peeling the substrate from the film, and the resin is cured by heating.

  In addition, the composite dielectric of the present invention as a prepreg can be laminated on a circuit board by a vacuum press. Specifically, it is desirable to perform pressing by bringing one side of the prepreg into contact with the circuit board and placing a metal foil on the other side.

  In addition, the composite dielectric of the present invention is used as a varnish, and an intermediate insulating layer of a multilayer printed wiring board is formed on a circuit board by coating and drying using screen printing, curtain coating, roll coating, spray coating, etc. Can do.

  In the present invention, in the case of a printed wiring board having an insulating layer as the outermost layer, through holes and via holes are drilled with a drill or laser, and the surface of the insulating layer is treated with a roughening agent to form fine irregularities. As a roughening method of the insulating layer, it may be carried out according to specifications such as a method of immersing the substrate on which the insulating resin layer is formed in a solution of an oxidizing agent, a method of spraying a solution of an oxidizing agent, etc. it can. Specific examples of the roughening agent include dichromate, permanganate, ozone, hydrogen peroxide / sulfuric acid, nitric acid and other oxidizing agents, N-methyl-2-pyrrolidone, N, N-dimethylformamide, methoxy An organic solvent such as propanol, an alkaline aqueous solution such as caustic soda and caustic potash, an acidic aqueous solution such as sulfuric acid and hydrochloric acid, or various plasma treatments can be used. These treatments may be used in combination. As described above, a conductor layer is formed on the printed wiring board with the insulating layer roughened by dry plating such as vapor deposition, sputtering, ion plating, or wet plating such as electroless / electrolytic plating. At this time, a plating resist having a pattern opposite to that of the conductor layer may be formed, and the conductor layer may be formed only by electroless plating. After the conductor layer is formed in this way, annealing treatment can be performed to further cure the thermosetting resin and further improve the peel strength of the conductor layer. In this way, a conductor layer can be formed on the outermost layer.

  Moreover, the metal foil in which the intermediate insulating layer is formed can be multilayered by laminating with a vacuum press. The metal foil on which the intermediate insulating layer is formed can be made into a printed wiring board having a conductor layer as the outermost layer by laminating with a vacuum press on the printed wiring board on which the inner layer circuit is formed. Moreover, the prepreg using the composite dielectric of the present invention is laminated together with a metal foil on a printed wiring board on which an inner layer circuit is formed by a vacuum press, so that the outermost layer is a printed wiring board having a conductor layer. can do. A predetermined through hole and via hole are drilled with a drill or a laser by a conformal method or the like, and the inside of the through hole and via hole is desmeared to form fine irregularities. Next, conduction between layers is achieved by wet plating such as electroless / electrolytic plating.

  Furthermore, if necessary, these steps are repeated several times. Further, after the outermost circuit formation is completed, the solder resist is applied by pattern printing / thermosetting by screen printing, or by curtain coating / roll coating / spray coating. A desired multilayer printed wiring board is obtained by forming a pattern with a laser after full surface printing and thermosetting.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
<Production Example 1: Perovskite complex oxide coarse particles (BaCaTiZr system)>
Charge water into the container and stir for 1 hour or more with barium carbonate, calcium carbonate, titanium oxide and zirconium oxide so that the powder concentration becomes 20 to 30% by weight while stirring, and to have a predetermined composite oxide composition. To obtain a slurry. This slurry was treated with a bead mill so that the average particle size of solid content determined by the laser light scattering method was 0.47 μm and the maximum particle size distribution was 3 μm or less. This slurry was granulated and dried using a spray bag dryer to obtain a spherical granulated powder. The spherical granulated powder had an average particle size of 33.4 μm determined by the laser light scattering method. The slurry injection specification of the spray bag dryer was 20,000 rpm with a 100 mmφ disk, and the drying chamber temperature was 105 ° C. The obtained granulated powder was charged into an alumina container having a porosity of 20% or more, and baked at 1225 ° C. for 20 hours. The obtained fired body was crushed with a coffee mill, and passed through a sieve having an opening of 100 μm to obtain spherical composite perovskite particles. The obtained composite perovskite particles had an average particle diameter (D ₅₀ ) of 22.5 μm, a BET specific surface area of 0.62 m ² / g and an A / B ratio of 1.003 ((BaO + CaO) / (TiO ₂ + ZrO ₂ )). Ba _(0.981) Ca _(0.020) Ti _(0.848) Zr _(0.150) O ₃ . The average particle size of the composite perovskite particles was determined by a laser light scattering method.

<Production Example 2: Perovskite complex oxide coarse particles (BaCaTiZr system)>
Spherical composite perovskite particles were obtained in the same manner as in Production Example 1 except that the firing temperature was changed to 1250 ° C. The resulting composite perovskite particles have an average particle diameter (D ₅₀ ) of 21.5 μm, a BET specific surface area of 0.85 m ² / g and an A / B ratio of (1.00) ((BaO + CaO) / (TiO ₂ + ZrO ₂ )). Ba _(0.980) Ca _(0.020) Ti _(0.849) Zr _(0.151) O ₃ having a molar ratio of The average particle size of the composite perovskite particles was determined by a laser light scattering method.

<Production Example 3: Perovskite complex oxide coarse particles (BaCaTiZr system)>
Water is charged in a container, a predetermined amount of a dispersant (poise 2100 manufactured by Kao Corporation) is added, and the titanic acid is adjusted so that the powder concentration becomes 20 to 30% by weight while stirring and a predetermined composite oxide composition is obtained. A barium precursor, barium carbonate, calcium carbonate and zirconium oxide were charged and stirred for 1 hour or longer to obtain a slurry. This slurry was treated with a bead mill so that the average particle size of the solid content determined by the laser light scattering method was 0.54 μm and the maximum particle size distribution was 3 μm or less. This slurry was granulated and dried using a spray bag dryer to obtain a spherical granulated powder. The spherical granulated powder had an average particle size of 30.3 μm determined by a laser light scattering method. The slurry injection specification of the spray bag dryer was 20,000 rpm with a 100 mmφ disk, and the drying chamber temperature was 105 ° C. The obtained granulated powder was charged into an alumina container having a porosity of 20% or more, and baked at 1175 ° C. for 20 hours. The obtained fired body was crushed with a coffee mill, and passed through a sieve having an opening of 100 μm to obtain spherical composite perovskite particles. The obtained composite perovskite particles have an average particle diameter (D ₅₀ ) of 21.4 μm, a BET specific surface area of 0.62 m ² / g and an A / B ratio of 1.001 ((BaO + CaO) / (TiO ₂ + ZrO ₂ )). Ba _(0.980) Ca _(0.020) Ti _(0.851) Zr _(0.149) O ₃ .
The barium titanate precursor used here is obtained by degassing barium titanyl oxalate, which is a starting material for synthesizing oxalate-based barium titanate, and further performing airflow pulverization. This barium titanate precursor had an average particle diameter (D ₅₀ ) of 2.8 μm and a BET specific surface area of 7.7 m ² / g.
The average particle size of the composite perovskite particles and barium titanate precursor was determined by a laser light scattering method.

<Production Example 4: Perovskite complex oxide coarse particles (BaCaTiZr system)>
Spherical composite perovskite particles were obtained in the same manner as in Production Example 3 except that the firing temperature was changed to 1200 ° C. The resulting composite perovskite particles have an average particle diameter (D ₅₀ ) of 20.4 μm, a BET specific surface area of 0.49 m ² / g and an A / B ratio of 1.001 ((BaO + CaO) / (TiO ₂ + ZrO ₂ )). Ba _(0.980) Ca _(0.020) Ti _(0.851) Zr _(0.149) O ₃ . The average particle size of the composite perovskite particles was determined by a laser light scattering method.

<Production Example 5: Perovskite complex oxide coarse particles (BaTi system)>
Water is charged in a container, a predetermined amount of a dispersant (poise 2100 manufactured by Kao Corporation) is added, and a barium titanate precursor is charged so that the powder concentration becomes 20 to 30% by weight while stirring, and stirring is performed for 1 hour or more. Thus, a slurry was obtained. This slurry was treated with a bead mill so that the average particle size of solids determined by the laser light scattering method was 0.51 μm and the maximum particle size distribution was 3 μm or less. This slurry was granulated and dried using a spray bag dryer to obtain a spherical granulated powder. The spherical granulated powder had an average particle size of 32.9 μm determined by the laser light scattering method. The slurry injection specification of the spray bag dryer was 20,000 rpm with a 100 mmφ disk, and the drying chamber temperature was 105 ° C. The obtained granulated powder was charged into an alumina container having a porosity of 20% or more and baked at 1100 ° C. for 20 hours. The obtained fired body was pulverized with a coffee mill and passed through a sieve having an opening of 100 μm to obtain spherical barium titanate particles. The obtained barium titanate particles have an average particle diameter (D ₅₀ ) of 19.2 μm, a BET specific surface area of 0.62 m ² / g, and an A / B ratio of 0.999 (BaO / TiO ₂ molar ratio). I had it.
The barium titanate precursor used here is obtained by degassing barium titanyl oxalate, which is a starting material for synthesizing oxalate-based barium titanate, and further performing airflow pulverization. This barium titanate precursor had an average particle diameter (D ₅₀ ) of 2.8 μm and a BET specific surface area of 7.7 m ² / g.
The average particle diameter of the spherical barium titanate particles and barium titanate precursor was determined by a laser light scattering method.

<Production Example 6: Perovskite complex oxide coarse particles (BaTi system)>
Spherical barium titanate particles were obtained in the same manner as in Production Example 5 except that the firing temperature was changed to 1150 ° C. The obtained barium titanate particles have an average particle diameter (D ₅₀ ) of 15.3 μm, a BET specific surface area of 0.40 m ² / g, and an A / B ratio of 0.999 (molar ratio of BaO / TiO ₂ ). I had it. The average particle size of the barium titanate particles was determined by a laser light scattering method.

<Production Example 7: Perovskite complex oxide coarse particles (BaTi system)>
Spherical barium titanate particles were obtained in the same manner as in Production Example 5 except that the firing temperature was changed to 1000 ° C. The obtained barium titanate particles had an average particle diameter (D ₅₀ ) of 18.9 μm, a BET specific surface area of 0.96 m ² / g, and an A / B ratio of 1.001 (BaO / TiO ₂ molar ratio). I had it. The average particle diameter of the barium titanate particles was determined by a laser light scattering method.

<Production Example 8: Perovskite complex oxide fine particles (BaTi type)>
After barium titanyl oxalate was deacidified, it was charged into a mullite container having a porosity of 20% or more and baked at 950 ° C. for 20 hours. The fired powder was air pulverized to obtain barium titanate having an average particle size of 0.75 μm and a BET specific surface area of 2.0 m ² / g. This barium titanate was similarly charged into a mullite container and baked at 1100 ° C. for 20 hours. The fired powder was subjected to airflow pulverization to obtain spherical barium titanate particles. The obtained barium titanate particles have an average particle diameter (D ₅₀ ) of 1.9 μm, a BET specific surface area of 0.90 m ² / g, and an A / B ratio of 1.001 (BaO / TiO ₂ molar ratio). I had it. The average particle diameter of the spherical barium titanate particles was determined by a laser light scattering method.

<Examples 1-7>
The perovskite type complex oxide coarse particles and the perovskite type complex oxide fine particles obtained in the above production examples were mixed with a commercially available mixer at a weight ratio as shown in Table 1, and the dielectric ceramic materials of Examples 1 to 7 were mixed. Obtained.

The dielectric ceramic materials of Examples 1 to 7 as inorganic fillers, the perovskite type composite oxide coarse particles obtained in Production Example 1 or the perovskite type obtained in Production Example 8 at a blending ratio as shown in Table 2 The composite oxide fine particles and the epoxy resin were kneaded to prepare an epoxy resin composition. In Table 2, kneading can be performed without any problem, and a uniform epoxy resin composition obtained is evaluated as “good”, and kneading can be performed, but a foam produced by thickening of the epoxy resin composition is evaluated as “△”. Those that were difficult to knead were evaluated as x.
The epoxy resin used here is a 99% by weight thermosetting epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: JER (registered trademark) 828EL, molecular weight of about 370, specific gravity of 1.17, nominal at 25 ° C. Viscosity 120-150P) and 1% by weight of an imidazole curing accelerator (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name: 2E4MZ).

  From the results shown in Table 2, in each of Examples 8 to 14 using the dielectric ceramic materials of Examples 1 to 7, 30% by volume or more could be filled in the epoxy resin. On the other hand, in Comparative Example 1, although it was possible to fill the inorganic filler with 30% by volume, bubbles were generated due to thickening of the epoxy resin composition. Furthermore, in Comparative Example 1, it was not possible to fill 35% by volume or more. In Comparative Example 2, the inorganic filler could be filled up to 50% by volume, but could not be filled up to 55% by volume.

  Next, among the epoxy resin compositions obtained by the evaluation of the kneading, those having an inorganic filler filling rate in the epoxy resin composition of 50% by volume and 55% by volume were evaluated for dielectric characteristics. The epoxy resin composition was cured at 140 ° C. for 5 hours to prepare a composite dielectric sample. A platinum film having a thickness of 30 nm was formed as an electrode on both surfaces of the obtained composite dielectric sample by vapor deposition, and then the frequency was measured with an impedance analyzer (Solartron 1255B) and interface (Solartron 1296). The dielectric constant and dielectric loss at 1 kHz and applied voltage of 1 V were measured. The results are shown in Table 3.

  From the results of Table 3, when compared at the same filling rate (50% by volume), Examples 8 to 12 have higher dielectric constants than Comparative Example 2, and in particular, Examples 10 to 12 are more than Comparative Example 2. The dielectric loss was low and the dielectric properties were very good. Further, even when the filling rate was 55% by volume, Examples 8 to 10 had no problem in dielectric loss and exhibited extremely high dielectric constants. Further, the dielectric constant obtained by filling 50% by volume in Examples 8 to 12 is the sample number 3 of Patent Document 2 (in the resin system having a dielectric constant larger than that of the epoxy resin used in this example, the dielectric filler) The dielectric constant obtained by filling 50% by volume in Examples 10 to 12 is the sample number 4 of Patent Document 2 (used in this example). It can be seen that in the resin system having a dielectric constant larger than that of the epoxy resin, the dielectric constant 46 of 60% by volume of the dielectric filler) is greatly exceeded.

Claims (7)

Perovskite (ABO ₃ ) type composite oxide coarse particles having an average particle size of 8 μm to 50 μm and a BET specific surface area of 0.3 m ² / g to 1.0 m ² / g and an average particle size of 0.7 μm to 3 μm A dielectric ceramic material comprising: perovskite (ABO ₃ ) type composite oxide fine particles having a BET specific surface area of 0.6 m ² / g or more and 3 m ² / g or less. The blending ratio of the perovskite complex oxide coarse particles is 10 wt% or more and 70 wt% or less, and the blending ratio of the perovskite complex oxide fine particles is 30 wt% or more and 90 wt% or less. The dielectric ceramic material according to claim 1 . The perovskite complex oxide fine particles are at least one selected from the group consisting of Ba, Ca, Mg and Sr as the A site element, and at least one selected from the group consisting of Ti and Zr as the B site element. dielectric ceramic material according to claim 1 or 2, characterized in that it consists of ABO ₃ type composite oxide is. The perovskite-type composite oxide coarse particles, the dielectric ceramic material according to any one of claim 1 to 3, characterized in that it does not contain the sintering aid. The dielectric ceramic material according to any one of claims 1 to 4 , wherein the dielectric ceramic material is used as an inorganic filler of a composite dielectric. A carbonate containing at least one element selected from the group consisting of Ba, Ca, Mg and Sr; an oxide containing at least one element selected from the group consisting of Ti and Zr; and a dispersion medium. A step of preparing a slurry containing a media mill so that an average particle size of a solid content in the slurry is 0.8 μm or less and a maximum particle size is 3 μm or less ,
A step of drying the slurry by a spray drying method to obtain a granulated powder; and a firing temperature of the granulated powder is adjusted in a range of 1000 ° C. or higher and 1400 ° C. or lower, and a BET specific surface area is 0.3 m ² / g or higher and 1 The manufacturing method of the perovskite type complex oxide coarse particle which has the process of obtaining the baked body which is 0.0 m < ² > / g or less. The method for producing perovskite complex oxide coarse particles according to claim 6 , wherein the slurry further contains a barium titanate precursor.

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