JP2001303102A - Composite dielectric material, and compacting material, compacting powder material, coating material, prepreg and substrate all using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite dielectric material good in the dispersibility of grains, capable of easily obtaining desired characteristics and capable of attaining the thinning of electronic parts, or the like, and to obtain a compacting material, a compacting powder material, a coating material, a prepreg and a substrate all using the same. SOLUTION: This composite dielectric material is obtained by coating the whole or a part of the surfaces of spherical metallic grains 1 with the average grain size of 0.1 to 10 μm with a dielectric layer 2 and dispersing the coated grains into a resin 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite dielectric material, a molding material for molding a capacitor, a piezoelectric element, a thermistor, a varistor, and the like using the same, a powder molding material, a printing paste, a casting material, and the like. Paints, prepregs and substrates.

[0002]

2. Description of the Related Art Mold materials as molding materials for high-frequency electronic components (molding materials by transfer molding or injection molding), casting materials (liquid materials for casting by potting or the like), paints such as printing pastes, and powder compacting. As a conventional material used for a powder material (a material for molding by pressing), a prepreg, a substrate, and the like, FIG.
As shown in (A), a composite dielectric material 32 in which a powder of dielectric particles 30 adjusted to a particle diameter of several hundred nm to several tens μm is dispersed in a resin 31 is used. This composite dielectric material 32
For example, in the case where is used for a laminated substrate, as shown in FIG. 6B, a glass cloth 33 is impregnated with the composite dielectric material 32 to form a prepreg 34 as an intermediate processed product of the laminated substrate. Then, a copper foil is stuck on the prepreg to form a laminate, and a desired conductor pattern is formed through a printed circuit board manufacturing process. The dielectric powder used in the composite dielectric material is obtained by firing the powder or pulverizing the sintered dielectric. The properties of the sintered dielectric used here are closely related to the properties of the final composite dielectric material.
It is selected in consideration of nδ and the like.

As shown in FIG. 6C, an electronic component such as a capacitor or a piezoelectric element is formed by fixing external electrodes 35 to both surfaces of the composite dielectric material 32.

[0004]

(Regarding the Conventional Composite Dielectric Material) In the case of the electronic component shown in FIG. 6C constituted by using the conventional composite dielectric material, there is no space between the external electrodes 35. Dielectric particles 3 made of a different material in resin 31
0 exists in a dispersed manner. In this case, the combined relative permittivity is determined by the volume ratio of the two types of materials.

FIG. 7 (A) shows a composite ratio when a dielectric powder (dispersion material) having a relative dielectric constant (ε) of 9,000 and a relative dielectric constant of 90 is dispersed in an epoxy resin while changing its content. It is an actually measured value of the dielectric constant (ε).

As can be seen from FIG. 7 (A), a powder having a relative dielectric constant of 9,000 dispersed in epoxy resin at 60 vol% has a combined relative dielectric constant of about 40 and a relative dielectric constant of about 1/2.
00, so that even if a dielectric material having a high relative permittivity is mixed, a very high relative permittivity cannot be obtained. Incidentally, in the case where a powder having a relative dielectric constant of 90 is dispersed in an epoxy resin, the composite relative dielectric constant is about 20 at 60 vol%, and about 1/5.
Has declined. The relative dielectric constant of a powder having a relative dielectric constant of 9,000 dispersed in epoxy resin at 40 vol% is about 1%.
On the other hand, the powder having a relative dielectric constant of 90 was dispersed in epoxy resin at 40 vol%, but the relative dielectric constant was about 12, which is not so large.

[0007] FIG. 7 (B) shows the result of examining the relationship between the powder content and the relative dielectric constant by preparing a double-sided copper-clad substrate by diluting the composite dielectric material with a solvent and impregnating the cloth with a glass cloth. Show. As can be seen from FIG. 7B, when the glass cloth is impregnated with the composite dielectric material, the difference in the relative dielectric constant of the dispersed powder of the composite dielectric material does not appear as compared with the case where no glass cloth is provided. This is because the volume of the glass cloth occupying in the substrate cannot be ignored, and the glass cloth having a relative dielectric constant of 7.0 has an influence on the composite relative dielectric constant determined by the volume ratio.

As described above, in order to obtain a high relative dielectric constant with a conventional composite dielectric material, a powder having a relative dielectric constant of 9000 is required
l% or more. However, in order to create a thin substrate, considering the adhesion to the copper foil and delamination between layers, the content of the composite dielectric material must be 50 vol% or less, so even if expensive dielectric powder is mixed, The dielectric constant cannot be improved much. In addition, conventional dielectric powders are obtained by crushing a sintered dielectric, have irregularities, and have a large particle size, so they have poor dispersibility, and have characteristics of electronic components and substrates such as thin capacitors and piezoelectric elements. Is difficult to stabilize.

The present invention relates to a composite dielectric material having good dispersibility of particles, easily obtaining desired characteristics, and achieving thinning of electronic parts and the like, a molding material using the same, and a compacting powder. It is an object of the present invention to provide a material, a paint such as a printing paste or a casting material, and a prepreg or a substrate.

Further, the present invention provides a composite dielectric material which can provide a high relative dielectric constant with a small amount of added dielectric material and is inexpensive in material cost, a molding material using the same, a compacting powder material, and a printing method. An object of the present invention is to provide a paint such as a paste or a casting material, and a prepreg or a substrate.

[0011]

According to a first aspect of the present invention, there is provided a composite dielectric material having an average particle diameter of 0.1 to 10 μm and covering all or a part of the surface of a spherical metal particle with a dielectric layer.
It is characterized in that one or more kinds of the coated particles are dispersed in a resin.

Here, the dielectric layer means a layer made of a substance having a higher dielectric constant than the resin, and preferably has a relative dielectric constant of 20 or more. As described above, small-diameter spherical particles in which all or part of the surface of the metal particles are covered with the dielectric layer can be obtained by a spray pyrolysis method as described in, for example, Japanese Patent Publication No. 3-68484. This spray pyrolysis method sprays a solution containing a metal salt into droplets, and heats the droplets in the air at a temperature higher than the decomposition temperature of the metal salt and higher than the melting point of the metal, whereby the metal powder is heated. How to make. When a dielectric layer is formed on the surface of the metal powder, for example, when a barium titanate layer is formed, a solution in which a compound such as a barium salt or a titanyl salt is dissolved together with the nickel salt is spray-heated, and these dielectric materials are sprayed. Heat at a temperature higher than the decomposition temperature of the body salt. This allows
A dielectric layer is formed on the surface of the substantially single crystal spherical metal particles. In this case, the reason that the particles are substantially a single crystal is based on the fact that the crystallinity was confirmed to be very high from a diffraction image of an electron diffraction result using a transmission electron microscope.

When these particles are formed by spray pyrolysis, the lower limit of the particle size is 0.05 μm and the upper limit is 20 μm.
It is about μm. Substantially, the average particle size is 0.1 to 10
μm, and particles having a particle size of 0.05 to 20 μm are 9
It is an aggregate of particles occupying 5 wt%.

Such dielectric-coated metal particles are dispersed and mixed in a resin so that the sintered dielectric is crushed into powder as in the prior art, and it is compared with a flake or a block having irregularities. Because of its spherical shape and small diameter, it is mixed with the resin with good dispersibility. When the particles are dispersed in a resin, the dielectric layer is, for example, 1 wt.
When the addition amount is%, it cannot contribute to the improvement of the dielectric constant, but can improve the insulation resistance and the withstand voltage of the composite dielectric material. When the dielectric layer is, for example, 1
If the amount exceeds wt%, it contributes to the improvement of the dielectric constant.

Since such dielectric-coated metal particles can be produced by the spray pyrolysis method as described above, they are inexpensive as compared with the conventional case of going through a number of steps such as sintering and pulverization of a dielectric. Can be provided. In the present invention, the composite dielectric material may be a resin further containing one or more oxide dielectric powders in addition to the dielectric coated metal particles in the resin.

The composite dielectric material according to claim 2 is the composite dielectric material according to claim 1, wherein the thickness of the dielectric layer is 0.0
0.5 to 5 μm.

When the thickness of the dielectric layer is 0.005 μm or more, it can contribute to the improvement of the dielectric constant or withstand voltage. On the other hand, if it exceeds 5 μm, it becomes difficult to produce particles. In this case, the thickness means the maximum thickness of the coating, and the coating does not necessarily cover the entire surface of the metal particle, but may cover about 50% of the surface of the metal particle.

The composite dielectric material according to claim 3 is characterized in that the coated metal particles are mixed in a resin of 30 to 98% by weight.

If the coated metal particles are less than 30% by weight, it is difficult to obtain desired characteristics when forming a substrate, an electronic component, a shielding material, etc., while if it exceeds 98% by weight, the molding is not performed in any case. Becomes difficult.

The composite dielectric material according to claim 4 is the composite dielectric material according to claim 1 or 2, wherein the metal particles are:
It is characterized by being made of one or more of silver, gold, platinum, palladium, copper, nickel, iron, aluminum, molybdenum, and tungsten. In the present invention, an alloy of the above metals or an alloy with another metal can be used.

According to a fifth aspect of the present invention, in the composite dielectric material of any one of the first to third aspects, for example, the dielectric layer is made of a titanium-barium-neodymium-based or titanium-barium-tin-based. , Lead-calcium, titanium dioxide, barium titanate, lead titanate, strontium titanate, calcium titanate, alumina, bismuth titanate, magnesium titanate, titanium-barium-strontium, Titanium-barium-lead, titanium-barium-zirconium, B
aTiO ₃ —SiO ₂ system, BaO—SiO ₂ system, CaW
O ₄ system, Ba (Mg, Nb) O ₃ system, Ba (Mg, T
a) O ₃ system, Ba (Co, Mg, Nb) O ₃ system, Ba
(Co, Mg, Ta) O ₃ -based ceramics and the like can be mentioned.

The composite dielectric material of the present invention comprises a molding material (Claim 6), a powder compacted powder material (Claim 7), a paint (Claim 8), a prepreg (Claims 9 to 11), and a substrate (Claim 9). Items 12 and 13) can be used. Further, the composite dielectric material of the present invention can be used as a piezoelectric material by using a piezoelectric material for the dielectric layer. The composite dielectric material of the present invention can be used as a semiconductor material by adjusting the thickness of the dielectric layer and the content of particles. The composite dielectric material of the present invention can be used as a material for electronic components such as a capacitor, a surface acoustic wave device, a piezoelectric device, a varistor, a thermistor, and a shielding material.

In the present invention, when the composite dielectric material of the present invention is used as an electronic component, the particles are spherical, so that the particles have good dispersibility, and the spray pyrolysis method provides small-diameter particles. Even so, an electronic component having good characteristics can be obtained. In addition, by forming a dielectric layer that meets the purpose on the surface, the dielectric layer works effectively and the amount of expensive dielectric can be reduced.

When the dielectric-coated metal particles are used as a capacitor material, various dielectric constants can be obtained by changing the thickness of the dielectric layer and the content of the particles with respect to the resin. In addition, the composite dielectric material used has good dispersibility because the particles have a small diameter and a spherical shape, and the characteristics are stable even when a thin structure is used.

When the composite dielectric material is used for the laminated substrate, a capacitor can be formed in the laminated substrate, and by changing the thickness of the dielectric layer and the mixing ratio of the particles to the resin, various types of capacitors can be formed. A layer having a dielectric constant can be obtained, and various passive elements having different characteristics can be formed in the laminated substrate. In addition, the composite dielectric material used has good dispersibility because the particles have a small diameter and are spherical,
The characteristics are stable even in the case of a thin configuration.

Further, if the above-mentioned composite dielectric material is used as a shielding material, it can be used as a molding material of a shield product requiring insulation, so that it can be mounted without an insulating material and mounting is easy.

[0027]

FIG. 1A is a sectional view showing a metal particle used in the present invention. 1 is a metal particle,
2 is a dielectric layer formed on the surface. The coated metal particles are produced by a spray pyrolysis method. The spray pyrolysis method is performed using an apparatus as shown in FIG.
That is, a spray nozzle 6 connected to the introduction pipe 5 of the solution to be sprayed is arranged at the upper end of the furnace tube 4 having the heating device 3 outside. A guide cylinder 8 connected to a carrier gas introduction pipe 7 is concentrically arranged around the nozzle 6. At the lower end of the furnace core tube 4, a storage unit 9 for manufacturing particles is provided.

In this apparatus, a solution containing a metal salt and a salt for forming a dielectric substance is sprayed from the nozzle 6, and at the same time, a carrier gas having characteristics such as oxidizing or reducing properties is discharged from the guide cylinder 8. While forming, the coated metal particles are formed in the furnace tube 4.

As the material of the metal particles, one or more of silver, gold, platinum, palladium, copper, nickel, iron, aluminum, molybdenum and tungsten are used. In addition, alloys of these metals or alloys with other metals can be used.

Materials for forming the dielectric layer 2 include titanium-barium-neodymium, titanium-barium-tin, titanium-barium-strontium, titanium-barium-lead, and titanium-barium-zirconium. Ceramics, such as those based on lead, calcium, titanium dioxide, barium titanate, lead titanate, strontium titanate, calcium titanate, bismuth titanate, and magnesium titanate. Further, C
aWO ₄ system, Ba (Mg, Nb) O ₃ system, Ba (Mg,
Ta) O ₃ system, Ba (Co, Mg, Nb) O ₃ system, Ba
_{(Co, Mg, Ta) O} 3 _based, BaTiO 3 -SiO ₂
Systems include BaO-SiO ₂ based ceramics or alumina.

The types of salts for forming the metal particles 1 and the dielectric layer 2 include nitrates, sulfates, oxynitrates, and the like.
Oxysulfate, chloride, ammonium complex, phosphate,
Carboxylate, metal alcoholate, resinate, boric acid,
One or more kinds of thermally decomposable compounds such as silicic acid are used.

These compounds such as salts are dissolved in water, an organic solvent such as alcohol, acetone and ether, or a mixture thereof. The heating temperature set by the heating device 3 is set to a temperature higher than the melting temperature of the metal particles 1.

As shown in FIG. 1B, the composite dielectric material is dispersed by mixing the dielectric-coated metal particles 1 produced by the spray pyrolysis method in a resin 10 using a ball mill or the like. obtain. As the resin 10, both thermosetting resins and thermoplastic resins can be used. Epoxy resins, phenol resins, polyolefin resins, polyimide resins, polyester resins, polyphenylene oxide resins, melamine resins, cyanate ester resins, diallyl Phthalate resin, polyvinyl benzyl ether compound resin, liquid crystal polymer, fluorine resin, polyphenylene sulfide resin, polyacetal resin, polycarbonate resin, ABS resin, polyamide resin, silicone resin, polyurethane resin, polyvinyl butyral resin, polyvinyl alcohol resin, ethyl cellulose resin, nitro At least one of cellulose resin and acrylic resin
More than one kind can be used alone or in combination.

As shown in FIG. 1 (C), the composite dielectric material of the present invention is obtained by dispersing and mixing the dielectric-coated metal particles in a resin 10 and heating and forming a plate-like material 11 on both sides. The capacitor can be formed by fixing the electrode 12 to the capacitor. Further, as shown in FIG. 1D, for example, a dielectric layer 14 having a relatively low dielectric constant is superimposed on both surfaces of a magnetic layer 13 in which magnetic particles are dispersed and mixed in a resin. A relatively high dielectric constant dielectric layer 15,
And a conductor pattern 16 composed of a ground pattern or a wiring pattern formed on at least one of the front and back surfaces of the plate material thus formed.
7 can be configured. These dielectric layers 14 and 15 have an internal conductor (not shown), and a conductor for inductance element formation (not shown) is formed on or outside the magnetic layer 13. The specific structure of the capacitor can be variously changed, for example, the internal electrode has a multilayer structure, a plurality of capacitors are built in, or inductors are stacked. The specific structure of the laminated substrate can be variously changed.

In the present invention, the dielectric-coated metal particles can be used as a molding material by forming the composite dielectric material into a powdery or fluid resin in order to obtain molded articles for various electronic parts. Further, a resin can be mixed with the composite dielectric material and used as a powder compacted powder material for pressure molding or heat and pressure molding. Further, the metal particles 1 coated with the dielectric layer 2 can be used as a printing paste by adding and mixing a binder as a resin and a plasticizer. Further, the composite dielectric material can be dispersed in a solvent and used as a casting material for casting (potting). Furthermore, it is possible to replace the resin in the composite dielectric material with a glass component or to add a glass component to the composite dielectric material, bond the particles by molding and baking, and form a shape according to the application. is there. Thereby, the heat resistance and the dielectric constant can be improved. Further, by providing a piezoelectric ceramic as the dielectric layer 2, it can be used as a piezoelectric material. The dielectric layer 2 can be used as a semiconductor material by using a material having a relatively low electric resistance, or by reducing the thickness of the dielectric layer 2 and reducing the amount of the resin 10. In addition, by using a material whose resistance is non-linear with respect to voltage or temperature for the dielectric layer 2, it can be used as a material for a varistor or a thermistor.

More specifically, as shown in FIG. 3 (A), it can be used as a material of a shield material 18 such as a layer or sheet applied in a layer or a case, a cover or the like. Further, as shown in FIG. 3 (B), by applying the composite dielectric material 20 to the glass cloth 19, it can be used as a prepreg 21 (one type of substrate material). By laminating and curing to form a conductor pattern on the surface or inside,
A substrate or a capacitor can be configured. Note that some prepregs do not have a glass cloth, and in this case, the composite dielectric material of the present invention can be used.

As shown in FIG. 3C, a piezoelectric material (including a lead-free material) is used for the dielectric layer 2, and electrodes 23 facing each other are formed on both surfaces of a body 22 formed of the piezoelectric material. The piezoelectric element 24 can be configured by providing the piezoelectric element 24. Further, a comb electrode can be provided on the surface of the element body 22 to constitute a surface acoustic wave device.

The dielectric layer 2 is made of NTC or PT.
By molding using a semiconductor material having C characteristics, FIG.
A thermistor 27 can be formed by obtaining the thermistor body 25 as shown in (D) and forming electrodes 26 on both surfaces thereof. By using a material having a varistor resistance characteristic for the material of the element body 23, that is, the dielectric layer 2, a varistor can be obtained. In any case, a material having good dispersibility and a small diameter can be used, so that it is easy to obtain a thin material having good dispersibility and good characteristics.

[0039]

EXAMPLE Nickel nitrate hexahydrate was prepared at a Ni concentration of 50 g / l.
It dissolved in water so that it might become. Next, Ba for nickel
1 wt%, 10 wt%, 20 wt%, 40 wt% of TiO ₃
Thus, a raw material solution was prepared by adding barium nitrate and titanyl nitrate. This aqueous solution was formed into fine droplets using the apparatus shown in FIG. 2 and supplied into a furnace tube 4 heated to 1500 ° C. together with a carrier gas adjusted to a weak reducing property.
The droplets were thermally decomposed to produce metal particles having BaTiO ₃ deposited on the surface using nickel as an internal metal. The generated metal particles are converted to nickel and BaT by X-ray diffraction.
it was confirmed that the iO is _3. The particle size distribution is 0.1
The average particle size was 0.6 μm.

The thus prepared dielectric-coated nickel particles were added to an epoxy resin at 30 vol%, 40 vol%, 50 vol%,
vol%, and mixed and dispersed by a ball mill together with a solvent. This dispersion solution was formed into a sheet having a thickness of 0.2 mm by a doctor blade method, and was temporarily dried at 70 to 80 ° C. for 1 hour.
In addition, the electrolytic copper foil is layered on the upper and lower surfaces, 2000-3000kP
The sheet was heated and pressurized at a temperature of 180 ° C. for 30 minutes at a pressure of “a” to form a sheet having a thickness of 0.6 mm. Next, this sheet was punched out using a mold so as to form a disk having a diameter of about 5 mm.

In addition, as comparative examples, those in which only nickel particles were prepared by spray pyrolysis and dispersed and mixed in an epoxy resin, and those in which dielectric powders having relative dielectric constants ε = 9000 and 90 were dispersed and mixed in an epoxy resin, respectively. The same sheet was prepared for only the epoxy resin, and the measurement was performed.

FIG. 4 shows the relationship between the capacitance of the disk created as described above and the impedance material analyzer (H, manufactured by HP).
P4921A), and the relative permittivity is calculated from the capacitance. As can be seen from FIG. 4, it was found that the relative dielectric constant was increased by dispersing and mixing the nickel powder or the dielectric-coated nickel powder in the resin.

Table 1 shows the samples other than those shown in FIG.
10wt% (BaTiO₃・ SiO ₂) ・ 90wt% Ni
(Sample No. 1) and 1 wt% Al₂O₃・ 99wt% N
i (sample No. 4) and add the epoxy resin particles
Relative dielectric constant when mixing ratio is 40 vol%
The edge resistance and the withstand voltage are shown.

As can be seen from Table 1, 1 in the present invention
_{0wt% BaTiO 3 · 90wt% Ni} ( sample No.2)
In the case of the above, a dielectric constant approximately the same as that obtained when a dielectric powder in which the relative dielectric constant ε = 9000 is dispersed is obtained.
= 90, a relative dielectric constant greater than that of the composite material obtained by dispersing the dielectric powder of = 90. Since the substantial volume of the dielectric on the surface of the metal powder is reduced by about 90% as compared with the conventional dispersion of the dielectric powder, the dielectric has almost the same relative dielectric constant. It is expected that the electrodes are formed of metal particles and that they are combined in an arrangement in which their capacitance increases.

Further, the sample Nos. As described in 2, 3, when the thickness of the dielectric layer 2 deposited on the surface of the metal particle 1 is changed by the weight at the time of blending, as the weight of the dielectric layer, that is, the thickness increases, the relative dielectric constant and the withstand voltage increase. Can be seen to increase.

Table 2 shows the dielectric (Ba) for nickel particles.
The results of measuring the relative dielectric constant, the insulation resistance, and the withstand voltage while changing the addition amount of TiO ₃ ) and changing the powder content are shown.
FIG. 5 is a graph of the dielectric constant portion of Table 2. As can be seen from Table 2 and FIG. 5, when the amount of the dielectric coating on the nickel particles is increased, the relative dielectric constant increases except for the case where the dielectric content of the powder at 30 vol% is 1 wt% and 10 wt%. I understand. In addition, the insulation resistance when considering the use as a laminated substrate is an insufficient value when the content of the nickel powder with respect to the resin is 50 vol% when the dielectric is not coated on nickel.

However, when the dielectric material is added to the metal particles even at 1 wt%, the insulation resistance (10 ¹¹ Ω · cm) which can be sufficiently used even when the content of the dielectric coated nickel powder with respect to the resin is 50 vol%. Have been obtained. In addition, the withstand voltage, which becomes a problem when used as a laminated substrate, increases with an increase in the dielectric coating amount, and shows a remarkable tendency except for 50 vol%. In the present invention, the content of the powder is 5
Even at 0 vol%, a sufficient relative dielectric constant can be obtained, a high insulating property can be obtained, and a withstand voltage can be obtained.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

As described above, according to the present invention,
The composite dielectric material is obtained by dispersing and mixing the powder consisting of the metal particles of the dielectric layer coating with the resin, so that a high dielectric constant can be obtained with a small amount of dielectric material, and the material cost is low. The various materials and substrates using the same can be provided. Further, when the composite dielectric material of the present invention is used, since the particles are spherical and have a small diameter, a product having good dispersibility of the particles and having stable characteristics such as capacitance, insulation resistance, and withstand voltage can be obtained. Can be

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of particles used in the present invention,
(B) is a sectional view showing an example of a composite dielectric material according to the present invention, (C) is a sectional view showing an example of a capacitor according to the present invention, and (D) is a sectional view showing an example of a laminated substrate according to the present invention. .

FIG. 2 is a configuration diagram showing an example of an apparatus used for generating particles by spray pyrolysis in the present invention.

FIGS. 3A to 3D are diagrams showing various products obtained by using the composite dielectric material of the present invention.

FIG. 4 is a graph showing the relationship between the content of particles and the dielectric constant of a composite dielectric material according to the present invention and a comparative example.

FIG. 5 is a graph showing the relationship between the ratio between metal particles and a dielectric and the dielectric constant of the composite dielectric material according to the present invention.

FIG. 6A is a cross-sectional view showing a conventional composite dielectric material,
(B) and (C) are sectional views of a prepreg and a capacitor using the composite dielectric material, respectively.

FIG. 7 (A) is a correlation diagram between the dielectric content and the dielectric constant of a conventional composite dielectric material, and FIG. 7 (B) is the dielectric constant of a prepreg formed by applying the composite dielectric material to a glass cloth. It is a correlation diagram between a body content and a dielectric constant.

[Explanation of symbols]

1: metal particles, 2: dielectric layer, 3: heating device, 4: furnace tube, 5: solution introduction tube, 6: spray nozzle, 7: carrier gas introduction tube, 8: guide tube, 9: production particles Accommodation section, 1
0: resin, 11: thin plate material, 12: electrode, 13: magnetic layer, 14: low dielectric constant dielectric layer, 15: high dielectric constant dielectric layer, 16: conductor pattern, 17: laminated substrate, 18:
Shielding material, 19: glass cloth, 20: composite dielectric material, 21: prepreg, 22: piezoelectric element, 23: electrode, 24: piezoelectric element, 25: thermistor element, 26: electrode, 27: thermistor

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01G 4/06 H01G 4/06 H01L 23/29 H05K 1/03 610R 23/31 H01L 23/30 R H05K 1/03 610 (72) Inventor Heng Kosara 1-13-1 Nihombashi, Chuo-ku, Tokyo T-D Corporation F-term (reference) 4F072 AA04 AA07 AA08 AB09 AB28 AE08 AE23 AF02 AG03 AG19 AL11 AL13 4J002 AA001 AB021 BB001 BD121 BE021 BE041 BE061 BF051 BG001 BN151 CB001 CC031 CC181 CD001 CF001 CG001 CH071 CK021 CL001 CM021 CM041 CN011 CP031 DA066 DA076 DA086 DA096 DA116 DC006 FA086 FB076 GQ00 HA09 4K018 BA01 BA02 BA04 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 BA03 EE07 GA10 5E082 AB01 BC39 FF14 FG08 FG26 FG27 FG34 PP03 PP09

Claims (13)

[Claims] 1. A surface of a substantially spherical metal particle having an average particle diameter of 0.1 to 10 .mu.m, which is entirely or partially coated with a dielectric layer, and one or more kinds of the coated particle are dispersed in a resin. A composite dielectric material, characterized in that: 2. The composite dielectric material according to claim 1, wherein said dielectric layer has a thickness of 0.005 to 5 μm. 3. The composite dielectric material according to claim 1, wherein said coated metal particles are mixed in a resin of 30 to 98% by weight. 4. The composite dielectric material according to claim 1, wherein said metal particles are silver, gold, platinum, palladium, copper, nickel, iron, aluminum, molybdenum, tungsten, or an alloy thereof. A composite dielectric material comprising one or more of these metals or alloys. 5. The composite dielectric material according to claim 1, wherein said dielectric layer is made of an oxide dielectric having a dielectric constant higher than a dielectric constant of said resin. Dielectric material. 6. A molding material comprising a composite dielectric material according to any one of claims 1 to 5. 7. A green compact formed by using the composite dielectric material according to any one of claims 1 to 5, wherein said coated metal particles are mixed in a resin at 90 to 98 wt%. Powder material. 8. A paint comprising a composite dielectric material according to any one of claims 1 to 5. 9. A prepreg comprising a composite dielectric material according to any one of claims 1 to 5. 10. A prepreg characterized by comprising a glass cloth embedded in a composite dielectric material according to any one of claims 1 to 5. 11. The prepreg according to claim 9, wherein the prepreg is provided with a copper foil. 12. A substrate comprising a material according to any one of claims 1 to 10. 13. The substrate according to claim 12, wherein the substrate is provided with a copper foil.