JP2001313208A - Composite magnetic material, magnetic molding material using the same, compact magnetic powder molding material, magnetic paint, prepreg, and magnetic board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide composite magnetic material which is excellent in insulating properties, workability when formed into a product, corrosion resistance, and high-frequency characteristics having a high withstand voltage, magnetic molding material using the same, compact magnetic powder molding material, magnetic paint, prepreg and magnetic board. SOLUTION: Metal particles 1 which are substantially spherical single crystals 0.1 to 10 μm in average grain diameter are all or partially coated with an insulating layer 2, one or more kinds of the coated metal particles are dispersed into resin 10 for the formation of composite magnetic material. Metal particles having excellent permeability or high coercive force are used as the above metal particles. The coated metal particles are formed through a spray thermal decomposition method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite magnetic material comprising metal particles and a matrix material (resin) coated with an insulator layer, and a magnetic molding material, a magnetic powder molding material, a magnetic paint, a prepreg, and a composite material using the same. The present invention relates to a magnetic substrate.

[0002]

2. Description of the Related Art A conventional composite magnetic material used as a magnetic material for a laminated electronic component is obtained by dispersing and mixing ferrite powder having an average particle diameter of several hundreds nm to several tens of μm in an organic material (Japanese Patent Application No. Hei 9 (1994) -108). -76341). A prepreg is prepared by applying the composite magnetic material to a glass cloth, and then a copper foil is attached to the prepreg to form a copper-clad laminate. By forming a desired pattern on the laminate, an inductance element having excellent high-frequency characteristics has been obtained.

As a material of a magnetic substrate using a multilayer substrate or a prepreg, there is a material in which magnetic metal particles are dispersed and mixed in a resin. (JP-A-8-78798, JP-A-10-79
No. 593). Japanese Patent Application Laid-Open No. 8-204486 discloses a composite magnetic material dispersed in a spherical iron carbonyl resin.

[0004] As a molding material using a composite magnetic material,
Japanese Patent Application Laid-Open No. 7-235410 discloses that the surface of a spherical iron powder having an average particle size of about 50 μm is insulated, and this is combined with a resin to form a motor,
Some are used as core materials for transformers.

[0005] As for the description regarding the electromagnetic shielding material,
By using magnetic metal particles of small size in the Journal of the Applied Magnetics Vol. 22, No. 4-2, 1998, pp. 885-888, the value of the complex magnetic permeability is higher up to high frequencies than cubic ferrite. In some cases, the shielding effect can be expected up to high frequencies.

However, in the case of a composite magnetic material composed of magnetic metal particles and a resin excluding ferrite, the insulation is low, and the imaginary part of the complex permittivity increases, and the imaginary part increases when the conductivity is high (the value of the imaginary part increases). Therefore, studies have been made to improve the insulation by treating the magnetic metal particles with a coupling material.

[0007]

[Problems to be Solved] (Prepreg containing glass cloth and copper-clad magnetic substrate) (a) When an inductance element is manufactured using a composite magnetic copper-clad substrate obtained by dispersing and mixing ferrite powder in an organic material, High-frequency characteristics tend to be poor when high-permeability ferrite powder is used. Conversely, low-permeability ferrite materials with excellent high-frequency characteristics do not provide sufficient magnetic permeability, and are satisfactory in any case. No satisfactory characteristics were obtained. (b) When a metal magnetic material such as carbonyl iron is used in place of ferrite powder, a composite magnetic substrate having a relatively high magnetic permeability and good high-frequency characteristics can be obtained. In the patterning process of (1), plating adhered to portions other than the pattern due to insulation failure of the element body (composite magnetic material), causing a short circuit between the patterns and causing a problem. Further, in the case of silicon iron, a composite magnetic substrate having a high magnetic permeability and a high saturation magnetic flux density can be obtained, but it cannot be used in a high frequency range and has a problem of low insulation.

(Magnetic molding material) (1) Sheet molding material (a) When a soft magnetic metal powder such as carbonyl iron or silicon iron is dispersed and mixed in a resin and molded into a sheet to be used as a shielding material, metal is used. Although a volume resistance of 10 ⁷ Ω · cm can be obtained by coupling treatment, oxidation treatment, or the like on the powder surface, when the withstand voltage is measured, it is 150 mm thick at a thickness of 1.0 mm.
V, and cannot be regarded as an insulating material when a voltage is applied, and there is a risk of an electrical short. (b) A shield material in which ferrite powder is dispersed instead of soft magnetic metal powder such as carbonyl iron or silicon iron has high volume resistance and almost no possibility of electrical short, but it has no effect on electric field shielding. Or, even in the magnetic shield, there is little effect on the low frequency side.

(2) Molding Material As a measure against radiation noise of a printed wiring board on which components are mounted, there is a method of molding a molding material such that the component mounting surface is entirely covered with a composite magnetic material in which ferrite is mixed with resin. Had been used.

A mold material in which ferrite powder is dispersed has no effect on the electric field shield, and also has little effect on the magnetic shield on the low frequency side. In a molding material in which a soft magnetic metal powder such as carbonyl iron or silicon iron is dispersed, the shielding effect is enhanced, but the insulating property is low, and poor characteristics are caused by poor insulation between patterns of the wiring board.

(3) Composite Magnetic Core Material The composite magnetic material used as a magnetic core of a choke coil, a transformer or the like is made of ferrite having an average particle size of several hundred nm to several tens μm, or magnetic metal particles whose surface is insulated. A material dispersed in a resin material such as a liquid crystal polymer, a PPS resin, and an epoxy resin has been used. It is molded into a desired shape and used as a magnetic core, but when ferrite is dispersed, the saturation magnetic flux density is small, it is difficult to use it for high power applications with large currents, and when using magnetic metal materials, Cannot secure sufficient insulation, and there was a problem in reliability.

(Regarding magnetic paint) For use in forming a magnetic circuit in a reactance element, coating for magnetic shielding, etc., a ferrite is mixed and dispersed in a resin and a solvent to prepare a printing paste, and a composite magnetic film is formed by screen printing or the like. Had gone. In the case of a composite magnetic material using ferrite, sufficient magnetic permeability and saturation magnetic flux density were not obtained, and there were some that were difficult for practical use. Although a method using metal magnetic powder instead of ferrite has been proposed, sufficient insulation cannot be secured, and the characteristics of reactance elements have deteriorated, and problems have occurred due to electrical short-circuits with surrounding metals on the shield surface.

(Molding Material for Dust Magnetic Powder) As a molding method for producing a composite magnetic material highly filled with metal magnetic powder, a resin such as an epoxy resin of several wt% is mixed with the magnetic powder and heated and pressed. A method of producing a molded article by using the method described above. However, because sufficient insulation cannot be secured,
Although treatment such as oxidation treatment of the metal surface was performed,
Even so, it was not enough and the withstand voltage was not enough for practical use. Further, the oxide film is not strong, and the molding method involving high pressure during molding has a disadvantage that the oxide film is broken at the time of pressure and it is difficult to bring out the original performance.

The present invention has good workability when producing a molding material having a high insulating property and a high saturation magnetic flux density.
The object of the present invention is to provide a composite magnetic material which has no problem of occurrence of corrosion and has good high frequency characteristics and withstand voltage, and a magnetic molding material, a powder magnetic powder molding material, a magnetic paint, a prepreg and a magnetic substrate using the same. And

[0015]

The composite magnetic material of the present invention has a spherical shape which is substantially a single crystal and has an average particle size of 0.1.
The present invention is characterized in that the whole or a part of the surface of magnetic metal particles having a diameter of 10 to 10 μm is covered with an insulating layer, and the at least one kind of coated metal particles is dispersed in a resin.

As described above, small-diameter substantially single-crystal spherical particles in which the surfaces of metal particles are covered with an insulator layer are obtained by, for example, a spray pyrolysis method described in Japanese Patent Publication No. 3-68484. be able to. This spray pyrolysis method produces a metal powder by spraying a solution containing a metal salt into droplets and heating the droplets in air at a temperature higher than the decomposition temperature of the metal salt and higher than the melting point of the metal. Is the way. When an insulator layer is formed on the metal surface, a solution in which a compound such as a salt constituting the insulator is dissolved together with the metal salt is spray-heated and heated at a temperature higher than the decomposition temperature of these insulator compounds. . Thereby, substantially single-crystal spherical metal particles are formed, and at the same time, an insulator layer is formed on the surface.

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.

Such an insulator-coated metal is more spherical than a conventional flake or powder block obtained by crushing ferrite by mixing and dispersing in a resin. Due to its small diameter, it is mixed with the resin with good dispersibility. Also, when these particles are dispersed in a resin, even if the insulating layer is added in a small amount of 1 wt% with respect to the metal particles, it can contribute to the improvement of the insulation resistance and also improve the withstand voltage. be able to.

Further, in the composite magnetic material, the shape of the coated metal particles retains the shape before being mixed with the composite magnetic material, and the coated insulating layer is retained without being destroyed. This contributes to the improvement of the withstand voltage as described above. Further, since the surface of the metal particles is covered with the insulator layer, there is no problem of corrosion such as rust.

When these particles are produced by the spray pyrolysis method, the lower limit of the particle size is about 0.05 μm, and the upper limit is about 20 μm. Substantially, the average particle diameter is about 0.1 to 10 μm, and particles having a particle diameter of 0.05 to 20 μm are 95 wt%.
Particles.

Since the diameter is small and the surface is covered with an insulator, eddy current loss, which is one of the losses as a magnetic material, is small despite being a composite magnetic material using metal particles, and high frequency characteristics Is good. Furthermore, the small diameter facilitates the production of thin electronic components.

Further, since the metal is substantially a single-crystal magnetic metal, a magnetic substrate requiring magnetism, an electromagnetic shielding material, a magnetic core such as a choke coil, a molding material such as a molding material,
A composite magnetic material suitable for a plastic magnet can be provided.

A composite magnetic material according to a second aspect is the composite magnetic material according to the first aspect, wherein the thickness of the insulator layer is 0.005.
５5 μm. When the thickness of the insulator layer is 0.005 μm or more, it can contribute to the improvement of the dielectric constant, insulation and withstand voltage. On the other hand, if the thickness exceeds 5 μm, it is difficult to form a uniform insulating layer.

The thickness in this case means the maximum thickness of the coating, and the coating does not necessarily cover the entire surface of the metal particle, and may occupy about 50% of the surface of the metal particle. I just need.

The composite magnetic material according to claim 3 is the first or second composite magnetic material.
Characterized in that the coated metal particles are mixed in a resin of 30 to 98% by weight. In this case, if the content of the coated metal particles is less than 30 wt%, the magnetic properties as a magnetic material, or a shielding material or a molding material are insufficient, and if it exceeds 98 wt%, molding becomes difficult in any case, making practical use difficult. .

According to a fourth aspect of the present invention, there is provided a magnetic molding material comprising the composite magnetic material according to any one of the first to third aspects. As described above, by covering the fine magnetic metal particles with the insulator layer, the insulation resistance is increased and the withstand voltage is also increased. Further, since the shield material and the mold material do not need to be insulated, the structure can be simplified by combining with other members without performing the insulated treatment. Even in the case of a magnetic core of a choke coil, winding can be performed without performing insulation treatment, and the structure can be simplified as well.

According to a fifth aspect of the present invention, there is provided a compacted magnetic powder molding material, wherein the composite magnetic material according to any one of the first to third aspects is used, and the coated metal particles are mixed in a resin of 90 to 98% by weight. Features.

By adopting the molding method by applying heat and pressure as described above, the amount of the coated metal particles added to the resin material can be easily increased, so that the magnetic permeability can be increased. Further, the use of the insulator-coated metal particles provides a highly insulating and highly reliable molding material. Further, in the composite magnetic material of the present invention, since the insulator layer is firmly coated, even if the coated metal particles are deformed at the time of pressurization, the insulator layer is hardly destroyed, and the compacting is difficult. It is a suitable material.

The magnetic paint of claim 6 is characterized by being constituted by using the composite magnetic material of any one of claims 1 to 3. By using such minute metal particles coated with an insulator layer, a high magnetic permeability can be obtained up to a high frequency range. In addition, high insulation resistance and high withstand voltage can be obtained by covering the insulator layer. Further, the use of the paint enables printing such as screen printing and casting, and enables thinning and adaptation to complicated shapes. The paint can be molded by a method such as casting.

The prepreg and the magnetic substrate according to the seventh to eleventh aspects are characterized by being constituted by using the composite magnetic material according to any one of the first to third aspects. By using such minute metal particles coated with an insulator layer, a high magnetic permeability can be obtained up to a high frequency range. In addition, high insulation resistance and high withstand voltage can be obtained by covering the insulator layer.

The molding method of the composite magnetic material of the present invention, such as injection molding, galvanizing, extruding, etc., is employed to obtain a molding material for a printed circuit board on which components are mounted, a package material for a semiconductor, and a coil material for a coil. It can be used as a mold material or a core or toroid of a transformer or a choke coil, a core material for a clamp filter, a housing and a cover material for a connector, a covering material for various cables, a housing for various electronic devices, and the like. In any case, it is a very suitable material because it has excellent insulating properties and magnetic properties.

Further, it is a very effective material as a material for plastic magnets, taking advantage of the fact that the holding power is improved by pulverizing magnetic metal particles. As the metal material in that case, Nd-Fe-B-based alloy, Sm-Co
Since a hard magnetic material such as a base alloy is used and the surface is coated with an insulator, it is possible to provide a composite magnetic material that is resistant to rust.

In the present invention, it is of course possible to replace the resin material with a vitreous material and combine the particles by molding and firing to form a shape according to the application.
It is also possible to realize a molding material that emphasizes heat resistance.

It is also possible to add not only the coated metal particles but also a glass component to the resin, or to form the coated insulating layer as a glass component and fire it after molding to obtain a composite magnetic material having excellent heat resistance. It is.

[0035]

FIG. 1A is a sectional view showing a metal particle used in the present invention. 1 is a metal particle,
Reference numeral 2 denotes an insulating 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 core tube 4 having the heating device 3 outside. Around the nozzle 6, a carrier gas introduction pipe 7 is provided.
Are concentrically arranged. Core tube 4
Is provided at the lower end of the container with a container 9 for manufacturing particles.

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

The material of the metal particles may be any material having magnetism, and in particular, nickel, iron or iron and other metals (nickel, molybdenum, silicon, aluminum,
An alloy selected from one or more of cobalt, neodymium, platinum, samarium, zinc, boron, copper, bismuth, chromium, titanium and the like is used. In addition, Mn-Al, Co-Pt, Cu-Ni-
An alloy such as a Co-based alloy can also be used.

The material for forming the insulator layer 2 may be an oxide composition having an insulating property, for example, silicon, boron, phosphorus, tin, zinc, bismuth, alkali or the like which forms a vitreous material. Metals, alkaline earth metals germanium, copper, zinc, aluminum, titanium, zirconium,
There is an oxide containing at least one element such as vanadium, niobium, tantalum, chromium, manganese, tungsten, iron, chromium, cobalt, a rare earth metal, and molybdenum.

The film may be formed of, for example, an oxide having the following dielectric properties. In particular,
Titanium-barium-neodymium system, titanium-barium-
Tin-based, titanium-barium-strontium-based, titanium-
Barium-lead, titanium-barium-zirconium,
Ceramics of lead-calcium type, titanium dioxide type, barium titanate type, lead titanate type, strontium titanate type, calcium titanate type, bismuth titanate type, and magnesium titanate type are exemplified. Furthermore, 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, BaTiO 3 -SiO ₂
Systems include BaO-SiO ₂ based ceramics or alumina.

Further, a magnetic oxide as shown below is used.
May be. The composition is Mn-Zn ferrite, N
n-Zn ferrite, Mn-Mg-Zn ferrite
, Ni-Cu-Zn ferrite, Cu-Zn ferrite
Site, Mn ferrite, Co ferrite, Li ferrite
, Mg ferrite, Ni ferrite and the like. Ma
Further, hexagonal ferrite such as Ba ferrite may be used.
No. In addition, Fe₂O ₃, Fe₃O₄Etc. with iron oxide
No problem.

The above-mentioned salts are dissolved in water, an organic solvent such as alcohol, acetone and ether, or a mixed solution 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. 1 (B), a composite magnetic material is obtained by dispersing and mixing the metal particles 1 coated with the insulator layer produced by the above-mentioned thermal decomposition spraying method in a resin 10 using a ball mill or the like. . As the resin 10, both a thermosetting resin and a thermoplastic resin can be used. For example, an epoxy resin, a phenol resin, a polyolefin resin, a polyimide resin, a polyester resin, a polyphenylene oxide resin, a melamine resin, a cyanate ester resin , 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 Any resin containing at least one kind of resin such as nitrocellulose resin and acrylic resin may be used.

The composite magnetic material obtained as described above is formed into a prepreg containing a glass cloth, a copper-clad magnetic substrate, a magnetic molding material, a magnetic paint, and a compacted magnetic powder molding material by various molding methods.

The composite magnetic material obtained according to the present invention may be coated with uncoated metal particles, flattened metal particles,
It is also possible to add oxide magnetic material and oxide dielectric particles according to the desired properties.

The molding material of the printed circuit board 20 on which the component 21 as shown in FIG. 1C is mounted by adopting a molding method such as injection molding, galvanizing and extrusion of the composite magnetic material of the present invention. 22, semiconductor package material, wound coil molding material or transformer or choke coil core 23 (24 is a winding) as shown in FIG. 1 (D), or toroidal, clamp filter core material, connector housing In addition, it can be used as a cover material, a covering material for various cables, a housing for various electronic devices, and the like. In any case, it is a very suitable material because it has excellent insulating properties and magnetic properties.

Further, the composite magnetic material of the present invention has the structure shown in FIG.
As shown in (A), for example, a dielectric layer 14 having a relatively low dielectric constant is superimposed on both surfaces of a magnetic layer 13 in which coated metal particles are dispersed and mixed in a resin.
4 is a laminate in which dielectric layers 15 and 15 having a relatively low dielectric constant are overlapped, and a conductor pattern 16 made of a ground pattern or a wiring pattern is formed on at least one of the front and back surfaces of the plate material thus formed. It can be configured as a part of the substrate 17. Internal conductors (not shown) are formed on these dielectric layers 14 and 15. Further, it can be used as a substrate material using a prepreg. Further, it can be used as a material for laminated electronic components such as a chip-shaped inductor element material and a filter.

Further, the composite magnetic material of the present invention has the structure shown in FIG.
As shown in (B), a material in which the metal particles 1 covered with the insulator layer 2 are dispersed in the resin 10 can be formed and used as the sheet-shaped or case-shaped shield material 19.

Further, it is a very effective material as a material for plastic magnets, taking advantage of the fact that the holding power is improved by pulverizing magnetic metal particles. As a metal material in that case, a hard magnetic material such as an Nd-Fe-B alloy or an Sm-Co alloy is used, and since the surface is coated with an insulator, it is possible to provide a composite magnetic material that is resistant to rust. Become.

It is of course possible to replace the resin material with a vitreous material and combine the particles by molding and firing to form a shape according to the application, and it is also possible to realize a molded material that emphasizes heat resistance. It is.

(Example 1: Pre-preg containing glass cloth and copper-clad magnetic substrate) FIG. 4 shows an apparatus shown in FIG. 2 in which barium titanate-coated iron powder prepared by a spray pyrolysis method was mixed with an epoxy resin. 7 shows the frequency characteristics of the magnetic permeability μ ′ and μ ″ of the composite magnetic material in comparison with those of a comparative example. The sample according to the present invention shows that the titanyl salt is adjusted so that barium titanate becomes 10 wt% with respect to iron. A barium titanate-coated iron powder having an average particle diameter of 0.6 μm was obtained by spraying an aqueous solution obtained by adding barium salt to an iron salt, and the content of the iron powder was 40 vol% with respect to the epoxy resin. The epoxy resin was a polyfunctional epoxy resin such as Epibis epoxy resin (Epicoat 1001 and Epicoat 100 manufactured by Yuka Shell Epoxy).
1007), 23.1 wt% of bisphenol A type polymer epoxy resin (Epicoat 1225 manufactured by Yuka Shell Epoxy Co.), and tetraphenylolethane type epoxy resin as an epoxy resin having a special skeleton. Resin (Eicoat 1031 manufactured by Yuka Shell Epoxy)
S) A main component containing 23.1% by weight of each, and a bisphenol A type novolak resin (YLH129B65 manufactured by Yuka Shell Epoxy) as a curing agent and an imidazole compound (2E4MZ manufactured by Shikoku Chemicals) as a curing accelerator. Was used. A mixed solution of toluene and methyl ethyl ketone and an appropriate amount of steel balls were added to 10% by weight of the resin component and 90% by weight of the magnetic metal particles prepared in the above step and dispersed and mixed by a ball mill to prepare a mixed solution of metal magnetic powder.

The solution obtained by the above process is formed into a sheet by a doctor blade method and dried to form a prepreg. A predetermined number of the prepregs are alternately stacked with a glass cloth, and a prepreg having a thickness of about 0.4 mm is formed by pressing and heating. This was a composite magnetic substrate (prepreg).

In Comparative Example 1, a ferrite having an initial magnetic permeability of 700 was mixed with 40 vol% epoxy resin.

In Comparative Example 2, a ferrite having an initial magnetic permeability of 10 was mixed with 40 vol% epoxy resin.

As can be seen from FIG. 4, in the sample according to the present invention, the value of μ ′ is higher than that of the comparative example from 10 MHz to 1 GHz, and in the case of the present invention, the high-frequency characteristics are good.

5 shows the frequency characteristics of the magnetic permeability μ ′ and μ ″ when iron is used as the metal particles and sodium-boron-zinc glass is used as the insulator layer 2. In this case, the glass is replaced by iron. The content of the particles with respect to the epoxy resin was set to 40 vol% as in the above example.

As is apparent from FIG. 5, such a composite magnetic material has better high-frequency characteristics than a composite magnetic material containing ferrite. In FIG. 6, the present invention using glass-coated magnetic metal particles and the conventional chip using ferrite as magnetic particles are used for a high-frequency bead element in which a coil is formed on a substrate using copper foil using the substrate shown in FIG. The frequency characteristics of the impedance of the bead element are compared and illustrated. As is clear from this, it can be seen that the case according to the present invention has a higher impedance in a high frequency range and has a better noise removing effect.

In the present invention, a composite magnetic substrate containing a glass cloth is used. However, a composite magnetic substrate not using a glass cloth can of course be supplied.

Example 2 Magnetic Molding Material (Shielding Material) In order to obtain the particles of the example of the shielding material shown in FIG. 3 (B), nickel was used as an internal metal and the surface was made of BaTiO _3.
Metal particles were prepared by spray pyrolysis so that the layers were deposited. The BaTiO ₃ layer to be deposited was blended so that the weight ratio of BaTiO ₃ was 1 wt% and 10 wt% in terms of nickel. The completed metal particles were confirmed to be nickel and BaTiO ₃ by X-ray diffraction analysis. The particle size distribution was 0.1 to 1.3 μm, and the average particle size was 0.6 μm.

The thus prepared metal particles were kneaded and dispersed in a liquid epoxy resin with a ball mill so as to have a volume of 40 vol%. This dispersion solution is obtained by the doctor blade method.
A sheet having a thickness of 200 μm was formed and dried to obtain a sample for magnetic shielding. Observation of FE-SEM and measurement results of insulation resistance and withstand voltage (Table 1 No. 1) revealed that BaTiO ₃ was present on the surface of the nickel powder and acted as an insulating film. . As shown in FIG. 7, the effect of the shield is not inferior to the conventional shield material. As the evaluation contents, for the shield material, a shield material is interposed between one noise source and the other detector, and a radio signal emitted from the noise source to the air is detected by the detector via the shield material. This is frequency characteristic data. The reference signal in the figure is a signal level when no shield material is provided. Fe-Si and composite ferrite are comparative examples in the case of a composite magnetic material using Fe-Si and ferrite as powders, respectively.

Example 3 Magnetic Paint The composite magnetic material of the present invention can supply various magnetic paints such as screen printable printing paints. Barium titanate was added to iron by 10% by spray pyrolysis in the same manner as in Example 1.
A barium titanate-coated iron powder and an ethyl cellulose resin were prepared by spraying an aqueous solution obtained by adding a titanyl salt or a barium salt to an iron salt so as to be wt%, and an average particle diameter of 0.6 μm, Butyl carbitol and terpineo
The mixture was dissolved in a mixed solution of phenol and a magnetic paint. Specifically, it was prepared by dispersing and mixing with a ball mill using steel balls as media. The composition was such that the coating metal particles were 40 vol% in the ethyl cellulose resin.

The paint was screen-printed at 0.1%.
mm, and the magnetic permeability μ ′, μ ″ of the laminated body
As a result of evaluating the frequency characteristics of the magnetic substrate, almost the same characteristics as those of the magnetic substrate of Example 1 were obtained. As described above, in the magnetic coating material of the present invention, the value of μ ′ increases from 10 MHz to 1 GHz, as in Example 1, and the high-frequency characteristics are good. The results are shown in Table 1 (2).

Apart from this example, the present coating composition can be formed by a method such as casting.

(Example 4: Compacted magnetic powder molding material) The composite magnetic material of the present invention can easily increase the amount of coated metal particles added to the resin material by adopting a molding method by heating and pressurizing. It is possible to supply a magnetic molding material having excellent magnetic permeability and insulation properties.

An aqueous solution obtained by adding a titanyl salt or a barium salt to an iron salt so as to have a barium titanate content of 10 wt% with respect to iron was sprayed by spray pyrolysis in the same manner as in Example 1 to obtain an average particle size. A barium titanate-coated iron powder having a diameter of 0.6 μm was prepared. This powder was mixed in an epoxy resin at 3 wt%, and pressed with a mold having an outer diameter of 7 mm and an inner diameter of 3 mm at 180 ° C. and 500 kPa to obtain a toroidal-shaped powder magnetic compact and evaluated magnetic properties. did. As a result, a highly filled composite magnetic material having a high magnetic permeability is realized, and the insulating property is also practical. The results are shown in Table 1 (2).

Further, it is also possible to add a glass component or to make the coating insulator layer a low-melting glass component and to perform a firing step after molding to obtain a composite magnetic material having excellent heat resistance.

[0066]

[Table 1]

[0067]

As described above, according to the present invention,
The composite magnetic material was prepared by dispersing small-diameter, spherical, insulator-coated metal particles in a resin with good dispersibility, so the surface coating provided high insulation properties, and therefore good workability and corrosion A composite magnetic material that has no problem and has good high-frequency characteristics and withstand voltage, and a magnetic molding material using the same,
A compacted magnetic powder molding material, a magnetic paint, a prepreg, and a magnetic substrate can be provided.

Further, since the insulator-coated metal particles of the present invention have good dispersibility, eddy current is reduced, and a magnetic molding material, a compacted magnetic powder molding material, a magnetic paint, a prepreg and a magnetic substrate excellent in high frequency characteristics are used. Can be provided.

[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 the composite magnetic material according to the present invention, (C) is a sectional view showing an example of a molding material using the composite magnetic material according to the present invention, and (D) is a sectional view showing the composite magnetic material according to the present invention. It is a figure showing an example of the used mold material.

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

FIGS. 3A and 3B are a side view and a cross-sectional view, respectively, illustrating an example of a magnetic substrate and a shield material manufactured according to the present invention.

FIG. 4 is a diagram showing frequency characteristics of magnetic permeability of a composite magnetic material according to the present invention and a comparative example.

FIG. 5 is a diagram showing frequency characteristics of magnetic permeability of a composite magnetic material according to the present invention used for a bead element and a comparative example.

FIG. 6 is a graph showing frequency characteristics of impedance of a bead element made of a composite magnetic material according to the present invention and a comparative example.

FIG. 7 is a graph showing the frequency characteristics of the amount of attenuation for a shield material made of a composite magnetic material according to the present invention and a comparative example.

[Explanation of symbols]

1: metal particles, 2: insulator 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, 13: composite magnetic layer, 14: low dielectric constant composite dielectric layer, 15: high dielectric constant composite dielectric layer, 16: conductor pattern, 17: laminated substrate, 19: shield plate, 20:
Printed circuit board, 21: mounted components, 22: composite coated magnetic material, 23: core material, 24: winding

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 201/00 201/00 H01F 1/37 H01F 1/37 H05K 1/03 610 H05K 1/03 610R (72) Inventor Heng Kosara 1-13-1 Nihonbashi, Chuo-ku, Tokyo T-D Corporation F term (reference) 4F072 AA07 AA08 AB09 AB29 AD23 AE08 AF02 AG03 AL11 4J002 AA011 AA021 CD001 DC006 FB076 4J038 AA012 EA011 HA062 HA066 HA212 HA216 HA292 HA396 HA446 HA476 HA562 KA07 KA12 KA15 KA20 NA03 NA17 NA21 NA22 5E041 AA00 AB00 AC05 BB01 BB03 BC05 CA01 CA10 NN04 NN17

Claims (11)

[Claims] An insulating layer covers all or a part of the surface of a magnetic metal particle having a substantially single crystal spherical shape and an average particle diameter of 0.1 to 10 μm.
A composite magnetic material characterized by being dispersed in a resin of at least one kind. 2. The composite magnetic material according to claim 1, wherein said insulator layer has a thickness of 0.005 to 5 μm. 3. The composite magnetic material according to claim 1, wherein said coated metal particles are mixed in a resin of 30 to 98% by weight. 4. A magnetic molding material comprising a composite magnetic material according to any one of claims 1 to 3. 5. A compacted magnetic powder molding material comprising the composite magnetic material according to claim 1, wherein said coated metal particles are mixed in a resin of 90 to 98% by weight. 6. A magnetic paint comprising a composite magnetic material according to any one of claims 1 to 3. 7. A prepreg comprising a composite magnetic material according to any one of claims 1 to 3. 8. A prepreg comprising: the composite magnetic material according to claim 1; and a glass cloth embedded in the composite magnetic material. 9. The prepreg according to claim 7 or 8, wherein
A prepreg characterized by having copper foil. 10. A magnetic substrate comprising a composite magnetic material according to any one of claims 1 to 3 or a prepreg according to any one of claims 7 to 9. 11. The magnetic substrate according to claim 10, wherein the magnetic substrate has a copper foil.