JP2007123376A - Compound magnetic substance and magnetic device using same, and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound magnetic substance which is superior in heat resistance and can be made compact and thin. <P>SOLUTION: The compound magnetic substance 1 is formed of a metallic magnetic powder and an organic resin. The filling rate of the metallic magnetic powder is set to ≥70 vol.% and ≤90 vol.%, and the organic resin is made of a fluorine elastomer having a fluorine polyether frame. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite magnetic body used for inductors, choke coils, transformers, and other inductance components of electronic equipment, a magnetic element using the same, and a method for manufacturing the same.

  As electronic devices become smaller and thinner, there is a strong demand for smaller and thinner parts and devices used in these devices. On the other hand, LSIs such as CPUs have been highly integrated, and a current of several A to several tens of A may be supplied to a power supply circuit supplied to the LSI. Therefore, in the inductance components such as choke coils used for these, in addition to the demand for downsizing, the cross-sectional area of the coil conductor contrary to this is increased to realize low resistance, and the inductance is reduced less due to DC superposition. It is needed. In addition, the use frequency is increased, and it is required that the loss at high frequency is low. Further, there is a strong demand to reduce the cost of parts, and it is necessary to assemble a magnetic element having a simple part structure in a simple process.

  For magnetic cores used in such inductance components, the higher the saturation magnetic flux density, the better the DC superimposition characteristics. The higher the magnetic permeability, the higher the inductance value, but the higher the saturation value, the easier the magnetic saturation. . For this reason, a desirable range is selected for the magnetic permeability depending on the application.

  Moreover, it is desired that the electrical resistivity is high and the magnetic loss is low.

  In response to these demands, the magnetic material actually used for the magnetic core is roughly classified into a ferrite system (oxide system) and a metal magnetic system. The ferrite system has high magnetic permeability, low saturation magnetic flux density, high electrical resistance, and low magnetic loss, and the metal magnetic system has high magnetic permeability, high saturation magnetic flux density, low electrical resistance, and high magnetic loss.

  The most common inductance component actually used is a magnetic element having an EE type or EI type ferrite core and a coil conductor. In this magnetic element, since the ferrite material has a high magnetic permeability and a low saturation magnetic flux density, if it is used as it is, the inductance value is greatly reduced due to magnetic saturation, and the direct current superimposition characteristic is deteriorated. Therefore, in order to improve the direct current superimposition characteristics, a gap is usually provided in the magnetic path of the ferrite core to reduce the apparent permeability.

  However, when a gap is provided, the core vibrates in this gap portion when driven by alternating current, and noise noise is generated. Further, since the saturation magnetic flux density remains low even when the magnetic permeability is lowered, the direct current superimposition characteristics are not better than when the metal magnetic powder is used.

On the other hand, Fe-Si-Al alloys, Fe-Ni alloys, etc., which have a higher saturation magnetic flux density than ferrite, may be used as the core material, but these metallic magnetic materials have an electrical resistance. Since it is low, if the operating frequency is increased to several hundred kHz to MHz as recently, eddy current loss increases, and it cannot be used as it is. For this reason, magnetic cores in which metal magnetic powder is dispersed in an organic resin such as an epoxy resin or a silicon resin have been developed. Since this magnetic core can incorporate a coil, it is possible to increase the cross-sectional area of the magnetic path, and it is advantageous to supply a small and thin inductance component at a low cost (for example, patent document) 1).
JP 2002-324714 A

  However, the inductance component in which the coil is built using the magnetic core in which the metal magnetic powder is dispersed in the conventional organic resin has no problem at the initial stage. Deterioration becomes a problem. In particular, for example, when used in electronic parts for electrical equipment, the test temperature that must satisfy heat resistance is 150 ° C., and high reliability in such an environment is desired.

  And the said conventional magnetic element had the subject that the insulation resistance (DC50V) by deterioration of the organic resin after a high temperature heat test (150 degreeC-4000 hours) was not maintained.

  The present invention solves the above-mentioned problems, and by using a composite magnetic material having sufficient magnetic characteristics and inductance characteristics even after a heat resistance test (150 ° C.-4000 hours) required for an inductance component, the heat resistance characteristics are improved. An object of the present invention is to provide an excellent composite magnetic body that can be reduced in size and thickness, a magnetic element using the same, and a method for manufacturing the same.

  In order to solve the above-mentioned conventional problems, the present invention provides a composite magnetic body formed of a metal magnetic powder and an organic resin, wherein the filling rate of the metal magnetic powder is 60 volume% or more and 90 volumes. %, And the organic resin is a fluoroelastomer having a fluoropolyether skeleton, a magnetic element using the same, and a method for manufacturing the same.

  The composite magnetic body of the present invention, a magnetic element using the same, and a method for producing the same can be obtained by using a fluorine elastomer having a fluoropolyether skeleton in an organic resin, and a composite magnetic body having particularly excellent heat resistance can be obtained. A magnetic element incorporating a coil using a body is excellent in heat resistance and can effectively use the magnetic path cross-sectional area, so that it is possible to realize a magnetic element having higher inductance and good DC superposition characteristics. Furthermore, since it is integrally molded with an organic resin, no noise is generated even when alternating current is applied. In addition, a high molding pressure is not required at the time of production, and production is easy and inexpensive.

(Embodiment 1)
Hereinafter, a composite magnetic body, a magnetic element using the same, and a manufacturing method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings.

  First, the magnetic core used in the first embodiment will be described.

  The magnetic core of the present invention is a composite magnetic body containing a metal elastomer having soft magnetic properties as a metal powder and a fluorine elastomer having a fluorine polyether skeleton as a thermosetting organic resin as an insulating binder.

  Next, constituent materials of the composite magnetic material will be described.

  The metal magnetic powder having soft magnetic properties is preferably a metal magnetic powder mainly composed of Fe. Specifically, Fe powder, Fe-Al, Fe-Si, Fe-Si-Cr, Fe-Si-Al alloys, Fe-Ni, Fe-Co, Fe-Mo-Ni alloys, etc. can be used. . However, if subcomponents other than the magnetic elements Fe, Ni, and Co increase, the saturation magnetic flux density decreases and the metal powder itself hardens. Therefore, these subcomponents are 10 wt% or less in total, more preferably 6 wt% or less. Is good.

  Further, the composition is 1 wt% ≦ component A ≦ 10 wt% and 0.05 wt% ≦ oxygen (O) ≦ 0.6 wt%, 0.01 wt% ≦ manganese (Mn) ≦ 0.2 wt% The balance is iron (Fe), and component A is silicon (Si), aluminum (Al), chromium (Cr), nickel (Ni), niobium (Nb), calcium (Ca), titanium (Ti), magnesium (Mg ) Including at least one is preferable.

  As a method for producing the metal magnetic substance powder, there are a water atomizing method, a gas atomizing method, an ingot pulverizing method, and the like. The powder shape may be any of a spherical shape, a flat shape, and a polygonal shape, but if it is substantially spherical, a dense composite magnetic body can be obtained in compression molding. In addition, as for the magnitude | size of a metal magnetic body powder, it is preferable that the average particle diameter is 1 micrometer or more and 100 micrometers or less. This is effective in reducing eddy current, and more preferably 50 μm or less. When the average particle diameter is less than 1 μm, the molding density is decreased, and thus the magnetic permeability is lowered, which is not preferable. Further, the smaller the coercive force Hc of the metal magnetic powder, the lower the core loss, but it is preferably 1200 A / m or less.

  In addition, the surface of this metal magnetic powder is lower in electrical resistance than ferrite, etc., so it is effective to coat the surface of the metal magnetic powder with an insulator coating for applications that require high frequency characteristics. As the material of the insulating film used for this, either an organic compound or an inorganic compound can be used, and the insulating film is formed of a material containing at least one selected from an organic silicon compound, an organic titanium compound, and a silicate compound. Is preferred.

  Moreover, an insulating film can also serve as an organic resin.

  The insulating film can be formed by adding an organic compound or an inorganic compound to the metal magnetic powder and coating it (additive coating method), or by oxidizing and heat-treating the metal magnetic powder itself. Either of the methods for forming a physical film (auto-oxidation method) can be used. Here, the combined use of an organic compound and an inorganic compound, and the combined use of an additive coating method and an auto-oxidation method are desirable.

  Next, the organic resin that is an insulating binder has two roles, that is, the role of containing the coil and the role of an electrically insulating material when the entire composite magnetic body is hardened as a molded body and used as a coil component. The organic resin as the binder is preferably a fluorine elastomer having a fluorine polyether skeleton represented by (Chemical Formula 1) in order to obtain particularly high insulation and high heat resistance.

  A fluorine elastomer having such a molecular structure is commercially available from Shin-Etsu Chemical Co., Ltd. under the trade name “SIFEL”.

  This resin material includes a one-component type and a two-component type liquid material depending on applications, and further includes a one-component type and a two-component type. Any of these can be used, and the same effect can be exhibited by appropriately selecting and using them.

  Further, by modifying the terminal of the fluorine elastomer having the fluorine polyether skeleton with silicon or an epoxy resin, it can be used as a fluorine elastomer satisfying various characteristics while taking advantage of its characteristics.

  In addition, the metal magnetic powder mixed with the organic resin made of fluorine elastomer may be used as it is, and may be transferred to the next forming step. However, once the powder is granulated through a mesh or the like, the fluidity of the powder is improved. Easy to use for. In addition, when using this organic resin component itself as an insulating coating of the metal magnetic powder, it is desirable to heat it to the vicinity of the curing temperature of the organic resin at the stage of granulation, as described above. By this preheating, the organic resin once decreases in viscosity and covers the metal magnetic powder, and the organic resin on the granule surface is in a semi-cured state, which prevents direct contact between the metal magnetic bodies during the next molding. High electrical resistance can be obtained.

  However, if this pre-curing progresses too much, it is difficult to increase the density during molding, and the mechanical strength after complete curing decreases. In order to prevent this, the entire organic resin may be divided into two, and one may be first mixed for forming an insulating film and precured, and then the rest may be mixed and used.

  As described above, the composite magnetic body is preferably composed of a metal magnetic powder and a fluorine elastomer having a fluorine polyether skeleton that is an organic resin, and more preferably, the surface of the metal magnetic powder is covered with an insulating film. It is good to coat.

  Moreover, you may add electrically insulating materials, such as solid powder other than those.

  Next, the manufacturing method of the said composite magnetic body is demonstrated.

  The metal magnetic powder is composed of silicon (Si) = 5 wt%, oxygen (0) = 0.1 wt%, manganese (Mn) = 0.2 wt%, and the balance being iron (Fe) by water atomization. The particle size (average particle size) was adjusted to 10 μm by controlling the atomizing conditions. Any method may be used for producing the metal magnetic powder, as long as the shape and particle size of the particles can be controlled depending on the purpose (sample Nos. 1 to 6).

  Thereafter, an organic silicon compound having a molecular weight of 1000, 5000 and 8000, which serves as an insulating film, is added to the surface of the obtained metal magnetic powder and mixed well by adding 0.5% by weight to the metal magnetic powder. It produced (sample No. 7-9).

  Then, as an organic resin, a fluorine elastomer having a fluorine polyether skeleton having a silicon-modified terminal was calculated and added so as to be 10% by volume, and mixed and kneaded to granulate, and then granulated through a sieve. At this time, in order to uniformly disperse the organic resin, the fluorine elastomer was diluted 1: 1 with a solvent made of metaxylene hexafluoride and added.

  In addition, although the organosilicon compound which plays the role of an insulating film was used for the surface of metal magnetic substance powder, the effect of the same electrical resistivity increase will be acquired if it is an organic material of molecular weight 200-8000. In particular, an organic silicon compound, an organic titanium compound, a silicate compound, and the like are optimal.

  For comparison, an epoxy resin (sample No. 1), a phenol resin (sample No. 2), a silicon resin (sample No. 3), and a polyimide resin (sample No. 4) are used as organic resins for comparison. It was.

  Next, the granulated powder is put into a mold having a diameter of 10 mm, and pressure-molded so that the filling factor of the metal magnetic substance powder is 80% by volume or more. A heat treatment was performed to obtain a disk-shaped sample having a diameter of 10 mm and a height of 1 mm. Of these, the curing conditions for epoxy resin (sample No. 1), phenol resin (sample No. 2), and silicon resin (sample No. 3) are 150 ° C.-1 hour, and polyimide resin (sample No. 4) is It was cured at 180 ° C. for 1 hour.

  In-Ga electrodes were applied and formed on the upper and lower surfaces of each sample obtained in this way, and the electrodes were pressed against this to measure the electrical resistivity between the upper and lower surfaces at a voltage of DC 50V. This disk-shaped sample was heat-treated for 150 ° C.-4000 hours corresponding to a heat resistance reliability test necessary as a coil component, and then the electrical resistivity was measured under the same conditions as described above. Moreover, the dimensional change rate after 180 degreeC-6 hours was measured using the same sample. The results are shown in (Table 1).

  From the results of (Table 1), all of the electrical resistivity of the composite magnetic body obtained by pressure molding by mixing fluorine elastomer having a fluoropolyether skeleton modified with silicon as an insulating binder was 40 MΩ · cm or more. However, the insulating film can also be used as an organic resin. As can be seen from the comparison of 7 to 9, the electrical resistivity can be further increased by covering the metal magnetic powder with an insulating film. However, if the manufacturing costs are compared, it is advantageous that the insulating film is also used as an organic resin.

  In addition, solvent resistance and PCT resistance of these samples were examined. The evaluation results are shown in (Table 2).

  From the results of (Table 2), it can be seen that the use of a fluorine elastomer having a fluorine polyether skeleton is excellent in solvent resistance and PCT resistance.

  In addition, what is necessary is just to determine the mixing ratio of metal magnetic body powder and organic resin by the desired filling rate of metal magnetic body powder. Generally, the relationship of organic resin (volume%) ≦ 100−metal magnetic substance powder (volume%) − insulating coating (volume%) is established.

  If the ratio of the organic resin (fluorine elastomer) is too low, the strength of the composite magnetic material is lowered, so that it is preferably 10% by volume or more. On the other hand, in order to make the filling factor of the metal magnetic powder 70% by volume or more, the organic resin needs to be 30% by volume or less.

  And by press-molding the composite magnetic body, the void portion is eliminated, so that the filling rate of the metal magnetic body powder is increased, and a high saturation magnetic flux density and a high magnetic permeability can be obtained. Here, in general, the higher the pressure to be pressed, the higher the filling rate of the metal magnetic powder, but the metal magnetic powder undergoes compressive strain due to pressurization. This compressive strain affects the magnetic properties of the metal magnetic powder and causes its deterioration. Therefore, in order to release the compressive strain, a composite magnetic body having excellent magnetic properties can be obtained by performing heat treatment after pressure molding.

(Embodiment 2)
Hereinafter, a composite magnetic body, a magnetic element using the same, and a manufacturing method thereof according to Embodiment 2 of the present invention will be described with reference to the drawings.

  1 to 4 are cross-sectional views of the magnetic element according to the second embodiment, where 1 is a composite magnetic body, 2 is a coil, 3 is a terminal portion, and 4 is a second magnetic body.

  In FIG. 1, the coil 2 is embedded in the composite magnetic body 1, and in FIGS. 2 to 4, the second magnetic body 4 is arranged in close contact with the inside or outside of the composite magnetic body 1. The magnetic path determined by the coil 2 passes through both the composite magnetic body 1 and the second magnetic body 4 in series.

  1 to 3, the magnetic path inside the coil 2 is configured to occur in a direction perpendicular to the surface of the chip-like magnetic element. On the other hand, in FIG. 4, the magnetic path inside the coil 2 is configured to be generated in a direction parallel to the surface of the chip-like magnetic element. Furthermore, in the structure of FIGS. 1 to 3, it is easy to increase the magnetic path cross-sectional area, but it is difficult to increase the number of windings. On the other hand, the structure shown in FIG.

  In the above figure, a square plate-like magnetic element having a thickness of about 1 to 10 mm and a length / thickness of one side of about 2/1 to 8/1 is assumed around 3 to 30 mm square. The dimensional shape is not limited to this, and may be a disk shape or the like. Furthermore, the shape of the composite magnetic body 1 can be changed depending on the shape of the mold. By forming the second magnetic body 4 using a dust magnetic body or ferrite, the shape has a considerable degree of freedom. It is possible to make more complicated shapes. Further, the winding method of the coil 2 and the cross-sectional shape of the conducting wire are not limited to these. When the second magnetic body 4 is used when the coil 2 is embedded in the composite magnetic body 1, the composite magnetic body 1 is used. Any structure may be used as long as the body 1 and the second magnetic body 4 are arranged in series in the magnetic path. In addition, since the magnetic path determined by the coil 2 passes through both the composite magnetic body 1 and the second magnetic body 4 in series, the combined permeability becomes an intermediate value between them, and only the composite magnetic body 1 is Since the effect of enlarging the magnetic path cross-sectional area by incorporating the coil 2 can be utilized as it is, it is possible to obtain a magnetic element having a larger inductance value.

  Next, a method for manufacturing the magnetic element having the structure shown in FIG. 1 will be described. FIG. 5 is a perspective view showing a manufacturing method of the magnetic element of FIG. The coil 11 is a coil made of a coated copper wire. In the case of FIG. 5, a round copper wire wound in two stages is used. The terminal portions 12 and 13 of the coil 11 are processed flat and further bent at a right angle with respect to the coil winding surface.

  First, the composition of the metal magnetic powder is aluminum (Al) = 7 wt%, oxygen (O) = 0.05 wt%, manganese (Mn) = 0.1 wt%, and the balance is iron (Fe). Yes, the particle size (average particle size) was controlled to be 15 μm by controlling the atomization conditions by the water atomization method. The surface of the obtained metal magnetic powder is mixed with an organic silicon compound having a viscosity of 2000, which serves as an insulating film, and having a viscosity of 2000% by weight with respect to the metal magnetic powder. The mixture was granulated by adding 5 to 40% by volume of fluorine elastomer having a fluoropolyether skeleton modified with silicon and mixing and kneading the mixture, and then granulating it through a sieve.

  A part of this granulated powder is put into a middle mold 23 in which the lower punch mold 22 is inserted halfway, so that the surface becomes flat. At this time, the upper and lower punch dies 21 and 22 may be used to perform temporary pressure molding at a low pressure.

  Next, using a coated copper wire with a diameter of 1.0 mm, a 4.5-turn coil 11 is prepared in a two-stage stacking with an inner diameter of 4 mm. It is placed on the granulated powder in this mold so as to be inserted into the cutout portions 24 and 25 of 23, and further filled with the granulated powder, and the filling rate is 70% by volume by the upper and lower punch dies 21 and 22. The pressure molding is performed to the shape of the magnetic element so as to be 90% by volume or less, and the main pressure molding is performed. The obtained molded body was removed from the mold, and the organic resin was heat-treated at 150 ° C. for 2 hours to form an insulating film on the surface of the metal magnetic powder, and the added fluoroelastomer was thermally cured. . After heat-curing, it is bent again so that the ends of the terminal portions 12 and 13 wrap around the lower surface of the magnetic element, and the size is 12.5 × 12.5 mm and the thickness is 3.4 to 3.6 mm in FIG. The magnetic element shown is obtained.

  The inductance (L) value of the magnetic element built in the coil was measured under the conditions of measurement frequency: 100 kHz, measurement current value: 20A. The results are shown in (Table 3).

  In order to use in a frequency region of 100 kHz or higher, an inductance value L ≧ 0.8 μH, preferably L ≧ 1.0 μH is required, although it varies slightly depending on the application.

  Furthermore, this granulated powder was put into a metal mold having an outer diameter of 14 mm and an inner diameter of 10 mm, and pressure-molded so that the filling rate of the metal magnetic powder was 60% by volume or more and 90% by volume or less, and then taken out from the mold. Thereafter, heat treatment was performed at 150 ° C. for 2 hours to obtain a toroidal core having an outer diameter of 14 mm, an inner diameter of 10 mm, and a height of 3 to 4 mm. The permeability of the toroidal core was measured under the condition of a measurement frequency of 100 kHz. The results are shown in (Table 3).

  Further, this granulated powder is put into a mold having an inner diameter of 10 mm, press-molded so that the filling rate is 60% by volume or more and 85% by volume or less, and then taken out from the mold and heated at 150 ° C. for 2 hours. It processed and the disk-shaped sample of diameter 10mm and height 1mm was obtained. In-Ga electrodes were applied and formed on the upper and lower surfaces of the sample thus obtained, and the electrodes were pressed against this, and the electrical resistivity between the upper and lower surfaces was measured at a voltage of 50V. This disk-shaped sample was subjected to a heat resistance reliability test required for coil parts at 150 ° C. for 4000 hours, and then the electrical resistivity was measured under the same conditions as described above. The results are shown in (Table 3).

  As is clear from (Table 3), an excellent L value can be realized when the filling factor of the metal magnetic substance powder is 70% by volume or more. In terms of mechanical strength, the filling rate is preferably 90% by volume or less. The higher the filling rate of the metal magnetic powder, the better the magnetic properties. However, in order to ensure mechanical strength considering practicality, the filling rate needs to be 90% by volume or less.

  At this time, the method of taking out the terminals is not limited to the above method, and the terminals may be taken out on the upper and lower surfaces.

  2 to 4 can be basically manufactured by the same method. That is, in the structure of FIG. 2, the second magnetic body 4 previously wound with the coil 2 may be used, or the second magnetic body 4 may be inserted into the center of the coil 2 at the time of molding. 3, two second magnetic bodies 4 are placed where the upper and lower punch dies 21 and 22 are in contact with each other at the time of molding, or the magnetic element having the structure shown in FIG. The magnetic body 4 may be bonded together. As for the structure of FIG. 4, a coil in which the coil 2 is wound around the second magnetic body 4 in advance may be embedded at the time of molding.

  The shapes of the coils 2 and 11 may be selected according to the structure and application, the required inductance value or resistance value, such as a round wire, a flat wire, or a foil wire. As the material of the conductors of the coils 2 and 11, copper or silver is used because low electrical resistance is desirable, but copper is usually used. Further, it is desirable that the surface is coated with an insulating resin.

  The second magnetic body 4 is desired to have a high magnetic permeability, a high saturation magnetic flux density, and an excellent high frequency characteristic. In particular, the magnetic permeability needs to be higher than that of the composite magnetic body 1 of the present invention. As materials that can actually be used, ferrite sintered bodies such as MnZn ferrite and NiZn ferrite, Fe powder, metal magnetic powders such as Fe-Si-Al alloys and Fe-Ni alloys, and binders such as glass A dust core that is hardened with an agent and densified to a filling rate of about 90% by volume or more can be mentioned. Among them, the ferrite sintered body has high magnetic permeability, excellent high frequency characteristics, and low cost, but the saturation magnetic flux density is low. The dust core has a high saturation magnetic flux density and a certain level of high-frequency characteristics, but has a lower magnetic permeability than ferrite. Therefore, it may be selected from these according to the application, but considering the use under a large current, a dust core having a high saturation magnetic flux density is more desirable. When a dust core is used, the dust core itself has a lower electrical resistance than the composite magnetic body 1 of the present invention. Therefore, the dust core is difficult to use when exposed on the surface of the inductor, particularly the lower surface, and may need to be insulated. is there.

  In this case, a structure existing inside as shown in FIG. 2 is preferable to a structure where the second magnetic body 4 is exposed on the surface as shown in FIG. In addition, two or more types of second magnetic bodies 4 such as a NiZn ferrite sintered body and a dust core may be used in combination with one inductor.

  The composite magnetic body 1 of the present invention has the characteristics of a conventional dust core and composite magnetic body. In other words, it has a higher magnetic permeability and higher saturation magnetic flux density than a composite magnetic material, a higher electrical resistance than a dust core, and a coil embedded in the coil can increase the magnetic path cross-sectional area. The body itself has higher characteristics than the dust core and composite magnetic body. Furthermore, by combining with the second magnetic body 4 having a higher magnetic permeability, the effective magnetic permeability can be optimized, and a small and high characteristic magnetic element can be obtained. In addition, the manufacturing method applies a powder molding process, and it is only necessary to cure the organic resin at hundreds of degrees at the time of molding or after molding. Therefore, it is not necessary to anneal at a high temperature in order to produce, and it is easy to manufacture and low cost.

  The composite magnetic body according to the present invention, the magnetic element using the same, and the manufacturing method thereof are reduced in size and thickness because the magnetic core has excellent electrical resistivity, excellent magnetic properties and excellent strength. It can also be applied to applications such as transformers, electric motors, chokes, noise filters, etc.

Sectional drawing of the magnetic element in Embodiment 2 of this invention Sectional drawing of the magnetic element in said 2nd form Sectional drawing of the magnetic element in said 3rd form Sectional drawing of the magnetic element in the 4th form A perspective view showing a method of manufacturing a magnetic element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite magnetic body 2 Coil 3 Terminal part 4 2nd magnetic body 11 Coil 12, 13 Terminal part 21 Upper punch metal mold | die 22 Lower punch metal mold | die 23 Middle metal mold | die 24, 25 Notch

Claims (7)

A composite magnetic body formed of a metal magnetic powder and an organic resin, wherein the filling rate of the metal magnetic powder is 70 volume% or more and 90 volume% or less, and the organic resin is represented by (Chemical Formula 1) A composite magnetic material made of fluorine elastomer having a fluoropolyether skeleton.

The composite magnetic body according to claim 1, wherein an insulating film is formed on the surface of the metal magnetic powder. The composite magnetic body according to claim 2, wherein the insulating film is formed using at least one selected from an organic compound and an inorganic compound. The composite magnetic body according to claim 3, wherein the insulating coating is formed using at least one selected from the group consisting of an organic silicon compound, an organic titanium compound, a thermosetting silicone resin, a silicate compound, and a metal oxide. . 2. The composite magnetic body according to claim 1, wherein the metal magnetic body powder is a metal magnetic body powder containing Fe as a main component. The magnetic element which embedded the coil in the composite magnetic body as described in any one of Claims 1-5. A first step in which a metal elastomer powder is mixed with a fluorine elastomer having an uncured fluorine polyether skeleton as an organic resin and then granulated, and the granules and the coil are placed in a mold and pressure-molded. A method for manufacturing a magnetic element, comprising a step and a third step of curing the organic resin by heating.

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