JP6330645B2 - Ferrite core, electronic component, and power supply - Google Patents

Description

The present invention relates to a ferrite core for a power supply transformer using a Mn—Zn ferrite having a high saturation magnetic flux density near 100 ° C. and an improved strength.

A ferrite sintered body is used as a material for a core (magnetic core) of a power transformer for in-vehicle use. The sintered body of ferrite is called a ferrite core, and Mn—Zn based ferrite containing Mn and Zn is used. With the recent miniaturization of the power supply, a high saturation magnetic flux density is required for the miniaturization and low profile of the ferrite core. Further, the ferrite core is easily cracked or chipped when mounted on a power source, during transportation or use, and it is required to increase the strength of the ferrite core.

As a method for increasing the strength of the core, for example, Patent Document _{1, Fe 2 O 3: 52.0~54.0mol} %, ZnO: 10.0~15.0mol%, MnO: comprises the primary component the balance Mn- A technique is described that increases the strength of the ferrite core without changing the magnetic loss by containing Bi ₂ O ₃ : 50 to 200 ppm as a subcomponent in the Zn ferrite.

Further, for example, in Patent Document 2, MnO: 35.0~40.0mol%, ZnO : 5.0~10.0mol% Fe 2 O 3: in the Mn-Zn ferrite containing main component of the balance, as a sub-component V ₂ O ₅ : A technique for increasing the strength of the ferrite core by containing 1000 ppm or less and sintering at 1200 to 1250 ° C. is described.

JP 2001-233667 A JP-A-6-36920

From patent document 1 and patent document 2, it is possible to raise the intensity | strength of a ferrite core by containing a subcomponent. However, since the ferrite core may be damaged and the strength is not sufficient for the damage, it is required to further increase the strength of the ferrite core.

Therefore, an object of the present invention is to provide a ferrite core that can solve the above-described problems of the prior art. In particular, since it is for in-vehicle power supply, it is to provide a ferrite core having high saturation magnetic flux density near 100 ° C. and high strength.

For this purpose, the present inventors have included the contents of Fe ₂ O ₃ , ZnO, MnO, and SiO ₂ , CaCO _3, etc., which are contained as main components in Mn—Zn ferrite, and the grain boundaries. Attention was also paid to the ratio of the Si and Ca contents in the vicinity of the grain boundary, and intensive research was conducted on their characteristics. As a result, it has been found that a ferrite core having high saturation magnetic flux density and high strength can be realized in the vicinity of 100 ° C., and the present invention has been completed.

That is, the ferrite core according to the present invention is Mn—Zn ferrite containing a main component of Fe ₂ O ₃ : 51.0 to 56.0 mol%, ZnO: 5.0 to 14.0 mol%, and MnO: the balance. The Mn—Zn ferrite containing SiO ₂ : 50 to 300 ppm and CaCO ₃ : 200 to 3000 ppm as subcomponents with respect to this main component, the Mn—Zn ferrite being a polycrystal having a spinel structure. Yes, the ratio X (at%) of the composition of Ca and Si at point A where the concentration of Ca in the grain boundary is the maximum, and the composition of Ca and Si at point B that advanced from the point A by 5 nm toward the inside of the particle The ratio Y (at%) satisfies the following formulas (1) and (2). However, the ratios X and Y are represented by Formula (3).
0.5 ≦ X ≦ 1.0 (1)
X + 0.05 ≦ Y ≦ X + 0.50 (2)
X, Y = Ca concentration (at%) / Si concentration (at%) (3)

Further, the ferrite core of the present invention is characterized in that it contains at least one of Nb ₂ O ₅ : 50 to 750 ppm, CoO: 200 to 4000 ppm, and TiO ₂ : 100 to 6000 ppm with respect to the main component as a subcomponent. It is preferable that

The electronic component of the present invention is configured using the ferrite core.

A power supply device according to the present invention includes the electronic component described above.

According to the present invention, since a ferrite core having a high saturation magnetic flux density near 100 ° C. and high strength can be obtained, it is possible to provide an electronic component and a power source that can cope with a large current and reduce quality deterioration due to mechanical damage. Is possible.

It is the schematic diagram which expanded a part of cross section of the ferrite core which concerns on embodiment of this invention. (A) It is a perspective view which shows the E-shaped ferrite core which concerns on embodiment of this invention. (B) It is a perspective view which shows an example of the trans | transformer which concerns on embodiment of this invention. It is a block diagram which shows the structure of the switching power supply device based on embodiment of this invention. 2 is a block diagram schematically showing a main part of an automobile provided with a switching power supply device 300. FIG. (A) is a cross-sectional photograph of a ferrite core, (b) a TEM observation image and a composition analysis location. It is a figure which shows the baking pattern based on embodiment of this invention.

First, the reasons for limiting the composition ranges of the main component and the subcomponent constituting the Mn—Zn ferrite in the present invention will be described. The ferrite core of the present invention can achieve high saturation magnetic flux density and high strength in the vicinity of 100 ° C. by appropriately selecting the composition range described later.

The ferrite core of the present invention contains 51.0 to 56.0 mol% of Fe ₂ O ₃ as a main component. When Fe ₂ O ₃ is less than 51.0 mol%, the saturation magnetic flux density in a high temperature region of 100 ° C. or higher becomes small. On the other hand, when Fe ₂ O ₃ exceeds 56.0 mol%, the magnetic loss at 100 ° C. or higher increases. That is, when the main component is in the above range, it becomes unsuitable as the magnetic core of the power transformer. Therefore, the _Fe 2 _{O 3} as a main component 51.0~56.0mol%. A preferred amount is 52.0-55.0 mol%.

The ferrite core of the present invention contains 5.0 to 14.0 mol% of ZnO as a main component. When ZnO is less than 5.0 mol%, the saturation magnetic flux density in a high temperature region of 100 ° C. or higher becomes small. On the other hand, when ZnO exceeds 14.0 mol%, the magnetic loss at 100 ° C. or higher increases. That is, when the main component is in the above range, it becomes unsuitable as the magnetic core of the power transformer. Therefore, ZnO as a main component shall be 5.0-14.0 mol%. A preferred amount is 8.0 to 12.0 mol%.

The ferrite core of the present invention contains 50 to 300 ppm of SiO ₂ and 200 to 3000 ppm of CaCO ₃ as subcomponents. When SiO ₂ is less than 50 ppm or CaCO ₃ is less than 200 ppm, a grain boundary with high electrical resistance cannot be formed sufficiently, and magnetic loss increases, making it unsuitable as a magnetic core for a power transformer. On the other hand, when SiO ₂ exceeds 300 ppm or CaCO ₃ exceeds 3000 ppm, abnormal grain growth is promoted during sintering and magnetic loss increases, which is also unsuitable as a magnetic core for a power transformer. Accordingly, SiO ₂ is set to 50 to 300 ppm and CaCO ₃ is set to 200 to 3000 ppm as subcomponents in the ratio of the main component to the weight. Preferred amounts are 50 to 150 ppm for SiO ₂ and 500 to 2000 ppm for CaCO ₃ .

The ferrite core of the present invention contains 100 to 6000 ppm of TiO ₂ as an accessory component. Ti can be replaced with Fe in the spinel lattice as tetravalent Ti ions to reduce magnetic loss. In order to obtain the effect, 100 ppm or more of TiO ₂ is added as a subcomponent in a ratio with respect to the weight of the main component. However, when the amount of TiO ₂ added is too large, the magnetic loss tends to increase. Accordingly, it is preferable that 100 to 6000 ppm of TiO ₂ is contained as a subcomponent in a ratio with respect to the weight of the main component. An even more preferred amount is 1000 to 3000 ppm.

The ferrite core of the present invention contains 200 to 4000 ppm of CoO as a subsidiary component. Co is effective in reducing magnetic loss. In order to obtain the effect, 200 ppm or more of CoO is added as a subcomponent in a ratio with respect to the weight of the main component. However, if the amount of CoO added is too large, the magnetic loss tends to increase. Therefore, it is preferable to contain 200 to 4000 ppm of CoO as a subcomponent in a ratio with respect to the weight of the main component. An even more preferred amount is 500 to 3000 ppm.

The ferrite core of the present invention contains 50 to 750 ppm of Nb ₂ O ₅ as a subcomponent. Since Nb tends to segregate at the grain boundaries, it is effective for promoting the formation of grain boundaries and increasing the electrical resistance at the grain boundaries. In order to obtain the effect, 50 ppm or more of Nb ₂ O ₅ is added as a subcomponent in a ratio to the weight of the main component. However, if the amount of Nb ₂ O ₅ added is too large, abnormal grain growth is promoted during sintering, and magnetic loss increases. Therefore, it is preferable to contain 50 to 750 ppm of Nb ₂ O ₅ as a subcomponent in a ratio with respect to the weight of the main component. An even more preferred amount is 100-300 ppm.

By adding Ti, Co and Nb simultaneously, the effect is further enhanced. In the Mn-Zn ferrite in which the crystal has a spinel structure, Co is present at the apex of the octahedron around the ions, and is dissolved in the B site that is six-coordinated to reduce the magnetic loss. The effect of reducing is obtained. However, when Co is added alone, it dissolves not only in the B site but also in the A site, and a sufficient effect on the amount added cannot be obtained. Therefore, it is considered that by adding Ti at the same time, Co easily dissolves in the B site, and an effect of reducing a large magnetic loss can be obtained as compared with adding Co alone. Further, Nb contributes to grain boundary formation and has an effect independent of the addition of Co and Ti. Therefore, when added at the same time, the effect of suppressing magnetic loss at 100 ° C. or higher is obtained simultaneously with the effect of Co and Ti. It is done.

FIG. 1 is an enlarged schematic view of a part of a cross section of a ferrite core. The Mn—Zn ferrite 100 is formed from particles 1 and grain boundaries 2 existing between the particles. As shown in FIG. 1, the composition analysis of Si and Ca is performed in the normal direction of the grain boundary existing between any two grains, and the point where the concentration of Ca is maximum in the grain boundary is defined as point A. A point that is 5 nm away from the point A in the normal direction of the grain boundary is defined as a point B. The present inventors have found that the strength of Mn—Zn ferrite increases when the composition ratio of Si and Ca (Ca / Si ratio) at points A and B satisfies the formula (2).

However, in the grain boundary used when determining point A and point B, the grain boundary shared by three or more grains is excluded. This is because the grain boundary shared by three or more particles has a composition different from the grain boundary between two particles. Moreover, there are a plurality of normal directions of grain boundaries shared by three or more grains, and the normal directions cannot be uniquely determined.

Since the particles of Mn—Zn ferrite contained in the ferrite core of the present invention satisfy the above-described formula (2), Ca has a composition distribution in which Ca is attenuated more slowly than Si in the internal direction of the particles. The stress applied to the crystal lattice is gradually attenuated. That is, since the stress applied to the crystal lattice inside the particle is relaxed, it is considered that the crystal inside the particle exists energetically stably and the strength of the entire crystal increases.

A manufacturing method suitable for the ferrite core in the present invention will be described. As a raw material of the main component, an oxide or a powder of a compound that becomes an oxide by heating is used. Specifically, Fe ₂ O ₃ powder, Mn ₃ O ₄ powder, ZnO powder, or the like can be used. What is necessary is just to select suitably the average particle diameter of the powder of each raw material in the range of 0.1-3.0 micrometers. After the raw material powder of the main component is wet mixed, calcining is performed at a predetermined temperature in the range of 800 to 1100 ° C. In calcination, the stabilization time at a predetermined temperature may be appropriately selected within the range of 0.5 to 5.0 hours. After calcining, the calcined material is pulverized until the average particle size becomes 0.5 to 3.0 μm, for example. In the present invention, not only the above-described main component materials, but also a composite oxide powder containing two or more kinds of metals may be used as the main component materials. For example, by oxidizing and baking an aqueous solution containing iron chloride and manganese chloride, a composite oxide powder containing Fe and Mn can be obtained. A mixture of the obtained powder and ZnO powder may be used as a main component. In this case, calcination is not necessary.

As a raw material for the auxiliary component, an oxide or a powder of a compound that becomes an oxide by heating is used. Specifically, SiO ₂ powder, CaCO ₃ powder, Nb ₂ O ₅ powder, TiO ₂ powder, Co ₃ O ₄ powder, or the like can be used. After calcining, the auxiliary components are added. In the addition of the auxiliary component, the above-mentioned pulverization may be performed after adding the auxiliary component raw material to the calcined material, or the auxiliary component raw material may be added and mixed after the calcined material is pulverized. . However, among the subcomponents, TiO ₂ and CoO can be subjected to calcining together with the main component raw materials.

A mixed powder composed of a main component and subcomponents is granulated into a granule for molding. Granulation can be performed using, for example, a spray dryer. As a suitable bond, for example, a small amount of polyvinyl alcohol (PVA) is added to the mixed powder, and this is sprayed with a spray dryer and dried. The particle size of the obtained granules is preferably in the range of 80 to 300 μm.

The obtained granule is molded into a desired shape using, for example, a press having a mold having a predetermined shape, and the molded body is subjected to a firing step. In the firing step, it is necessary to control the firing temperature and firing atmosphere. The firing temperature can be appropriately selected from the range of 1250 ° C to 1500 ° C. In order to sufficiently bring out the effect of the ferrite core of the present invention, it is preferable to fire in the range of 1300 to 1400 ° C. The firing atmosphere may be adjusted as appropriate in the partial pressure of oxygen in an atmosphere in which nitrogen and oxygen are mixed.

It cools to 950 degreeC from the calcination temperature in a baking process, and hold | maintains at 950 degreeC for 2 hours. By holding at a constant temperature of 950 ° C., formation of an amorphous grain boundary containing additive elements such as Si, Ca, and Nb is promoted. Next, the temperature is raised again to 1200 ° C. and held at 1200 ° C. for 10 to 30 minutes. Then, it cools to room temperature. By maintaining at a constant temperature of 1200 ° C., it is possible to realize a state in which Ca segregated at the amorphous grain boundary is appropriately dissolved in the inside of the particles. When the holding time at 1200 ° C. is short, the solid solution of Ca particles is insufficient and the effect of increasing the strength cannot be obtained. On the other hand, if the holding time at 1200 ° C. is long, Ca is excessively dissolved in the inside of the particles, so that the formation of grain boundaries becomes insufficient, resulting in an increase in magnetic loss and a decrease in strength.

In a general firing process of a ferrite core, reheating is not performed at the time of cooling, but by performing reheating, solid solution of Ca particles inside is promoted, and an effect of increasing strength can be obtained. .

The ferrite core obtained by firing can obtain a relative density of 93% or more, more preferably 95% or more.

The ferrite core obtained by the present invention can be used for a transformer, and the transformer obtained by the present invention can be used for a switching power supply device.

FIG. 2A is a perspective view showing an E-shaped ferrite core according to this embodiment. As shown in FIG. 2, the E-shaped ferrite core 200 is called an E-type core or the like, and is used for a transformer or the like. As a transformer in which an E-type core such as the ferrite core 200 is adopted, there is known a transformer in which two E-type cores are arranged opposite to each other as shown in FIG. If the ferrite core according to the present invention is used as the transformer core, the possibility of breakage of the ferrite core 200 is reduced, and therefore the reliability of the transformer can be improved.

FIG. 3 is a block diagram showing the configuration of the switching power supply apparatus. The switching power supply device 300 is a device (DC / DC converter) for converting the DC input voltage Vin into the DC output voltage Vout. The switching power supply device 300 includes an input filter 301 for removing noise components included in the DC output voltage Vin, A switching circuit 302 that converts the output into alternating current, a transformer 303 that transforms the output of the switching circuit 302, a rectifier circuit 304 that converts the output of the transformer 303 into direct current, and a smoothing circuit 305 that smoothes the output of the rectifier circuit 304 are provided. . If the ferrite core according to the present invention is used as the core of the transformer 303 included in the switching power supply device 300 having such a configuration, the possibility that the transformer 303 is damaged is reduced, and thus the reliability of the switching power supply device 300 is improved. It becomes possible.

The switching power supply device 300 shown in FIG. 3 is particularly preferably used as a switching power supply device for automobiles.

FIG. 4 is a block diagram schematically showing main parts of an automobile provided with the switching power supply device 300.

As shown in FIG. 4, when the switching power supply device 300 is used for an automobile, the switching power supply device 300 is provided between the high voltage battery 310 and the electric equipment 320 and the low voltage battery 330 and is supplied from the high voltage battery 310. The high voltage of about 144V or about 288V is stepped down to about 14V and supplied to the electric device 320, and the low voltage battery 330 is charged. Examples of the electric device 320 include an air conditioner and an audio device provided in an automobile.

Charging the high voltage battery 310 is performed by electric power supplied from the power generation device 340. The output of the high voltage battery 310 is also supplied to the motor 350, and the motor 350 drives the drive system 360 based on a high voltage (about 144V or about 288V) supplied from the high voltage battery 310. In the fuel cell vehicle, the fuel cell body is the power generation device 340, and in the hybrid vehicle, the motor 350 also serves as the power generation device 340.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

Fe ₂ O ₃ powder, Mn ₃ O ₄ powder and ZnO powder as raw materials of main components, and SiO ₂ powder, CaCO ₃ powder, Nb ₂ O ₅ powder, TiO ₂ powder and Co ₃ O ₄ powder as raw materials of auxiliary components Was used.

Tables 1 to 3 show main components and subcomponents of the Mn—Zn-based ferrite implemented in the present invention.

Each powder was weighed so that the main components and subcomponents of the Mn—Zn-based ferrite obtained after firing had the compositions shown in Tables 1 to 3, and the powders were wet-mixed. Temporarily baked.

A binder was added to the obtained mixture, granulated, and molded to obtain a toroidal shaped body, an I-shaped shaped body, and an E-shaped shaped body. The obtained molded body was fired under oxygen partial pressure control. In the firing step, the temperature was maintained at 1300 ° C. and an oxygen partial pressure of 1.0 vol% for 5 hours, then cooled to 950 ° C., and held at 950 ° C. for 2 hours. Next, the temperature was raised again to 1200 ° C., maintained at 1200 ° C. for 0 to 40 minutes, and then cooled to room temperature.

Thus, a toroidal ferrite core (outer diameter 20 mm, inner diameter 10 mm, thickness 5 mm), I-shaped ferrite core (length 70 mm, width 8 mm, thickness 8 mm) and E-shaped ferrite core (Length 40 mm, height 15 mm, width 5 mm) was obtained.

Next, the measurement method of the present invention will be described.

The strength was measured using a square-shaped sintered body according to the method described in JIS R1601, using a test jig 3p-30 and an I-shaped core having a total length of 40 mm, and the value was determined as bending strength σb3. did.

The saturation magnetic flux density Bs at 100 ° C. was measured on a toroidal core with a DC magnetization characteristic tester (SK-110) manufactured by Metron Giken.

The composition analysis of Si and Ca was performed using a transmission electron microscope (TEM: JEM-2100F) provided with a focused ion beam (FIB) processing apparatus and an energy dispersive X-ray analyzer (EDS: JED-2300T). . In the TEM observation, particles having an average crystal grain size or larger were sliced with an FIB processing apparatus. The average crystal grain size was obtained by observing a cross section of the core center using an optical microscope, measuring the heelwood diameter of all crystals in the 1 mm × 1 mm field of view, and calculating an average value. FIG. 5 shows (a) a photograph of an optical microscope of a cross section of the ferrite core, (b) a TEM observation image, and a composition analysis portion. In the composition analysis, the composition analysis of Si and Ca was linearly analyzed in the normal direction of the grain boundary existing between the two particles, and the point where the Ca concentration was maximum progressed from the point A and from the point A toward the 5 nm intragranular direction. The point was point B, and the values of X and Y, which are Ca / Si ratios at each point, were obtained. At that time, the spot size of the electron beam was set to 1 nm or less. The measurement of the composition analysis of Si and Ca was performed at 10 different positions for each sample, and the average value of 8 times was excluded from the 10 times except for the highest and lowest Ca concentrations at point A. And Y.

The core loss Pcv at 100 ° C. is obtained by using a toroidal-shaped ferrite core and winding 5 turns on the primary side and 5 turns on the secondary side, and at a frequency of 100 kHz and a maximum magnetic flux density of 200 mT. The measurement was performed with an IWATSU BH analyzer (SY-8217).

The measurement results are shown in Tables 1-3. In the table, “-” indicates that the material is not added, and “x” indicates that the material is not implemented.

(Table 1)
The ferrite temperature was adjusted as shown in FIG. 6 to produce a ferrite core. After holding at 950 ° C., in the case of firing conditions in which the temperature is not raised to 1200 ° C. and the holding time at 1200 ° C. are short (Comparative Examples 1 and 2), the amount of Ca dissolved in the particles is small. The strength is about 100 MPa. On the other hand, when the holding time at 1200 ° C. is long (Comparative Example 3), solid solution of Ca from the grain boundary to the inside of the particle is promoted, and the strength is lowered.

(Table 2)
When Fe ₂ O ₃ is less than 51.0 mol% or ZnO exceeds 14.0 mol%, the saturation magnetic flux density in a high temperature region of 100 ° C. or higher becomes small. On the other hand, when Fe ₂ O ₃ exceeds 56.0 mol% or ZnO is less than 5.0 mol%, the magnetic loss at 100 ° C. or higher increases and the strength decreases. That is, when the main component is in the above range, it becomes unsuitable as the magnetic core of the power transformer.

(Table 2)
If the SiO ₂ content is less than 50 ppm or the CaCO ₃ content is less than 200 ppm, the grain boundary cannot be sufficiently formed and the strength is lowered, which makes it unsuitable as the magnetic core of the power transformer. On the other hand, when SiO ₂ exceeds 300 ppm or CaCO ₃ exceeds 3000 ppm, the crystal growth of Mn—Zn ferrite is inhibited during sintering and the strength is lowered, which is also unsuitable as a magnetic core of a power transformer. become.

Or more with respect to, as the main component, 51.0～56.0Mol% of _Fe 2 _{O 3, 5.0~14.0mol%} of ZnO, wherein the remainder of MnO, as an accessory component, a SiO ₂ 50 to 300 ppm, In the Mn—Zn ferrite containing 200 to 3000 ppm of CaCO 3, when the values of X and Y that are Ca / Si ratios satisfy 0.5 ≦ X ≦ 1.0 and X + 0.05 ≦ Y ≦ X + 0.50, It was confirmed that the effect of increasing the strength was developed.

(Table 3)
When TiO ₂ or CoO is added as a subcomponent, magnetic loss can be reduced. In order to obtain the effect, 100 ppm or more is added for TiO _{2 and} 500 ppm or more is added for CoO. On the other hand, when it exceeds 6000 ppm for TiO ₂ and 4000 ppm for CoO, the magnetic loss increases.

(Table 3)
When Nb ₂ O ₅ is added as a subcomponent, Nb tends to segregate at the grain boundary, and therefore it is effective for promoting the formation of the grain boundary and increasing the electrical resistance at the grain boundary. In order to obtain the effect, Nb ₂ O ₅ is added by 50 ppm or more. On the other hand, when Nb ₂ O ₅ exceeds 750 ppm, abnormal grain growth is promoted during sintering, and magnetic loss increases.

(Table 3)
By adding Ti, Co, and Nb at the same time, the effect is further enhanced, and the effect of suppressing magnetic loss at 100 ° C. or higher can be obtained.

From the above examples, in order to increase the strength of the Mn—Zn ferrite while maintaining the saturation magnetic flux density, it is effective to adjust the Ca / Si ratio X and Y to be appropriate amounts. . Further, by adding Nb, Co and Ti as subcomponents other than Si and Ca to Mn—Zn ferrite, it is effective for suppressing magnetic loss at 100 ° C. or higher in addition to increasing strength.

As described above, since the ferrite core according to the present invention has a high saturation magnetic flux density in the vicinity of 100 ° C. and high strength, it can be suitably used for electronic components such as choke coils. In particular, it is suitable for a choke coil for a switching power supply.

1 particle 2 grain boundary 100 cross section 200 of Mn-Zn ferrite ferrite core (magnetic core)
201 middle leg 202 coil

Claims (4)

51.0～56.0Mol% iron oxide calculated as _Fe 2 _{O 3,} 5.0～14.0Mol% of zinc oxide calculated as ZnO, consists mainly composed balance being manganese oxide MnO, relative to the weight of the main component As a subcomponent, Si is 50 to 300 ppm in terms of SiO ₂ and Ca is 200 to 3000 ppm in terms of CaCO ₃ , wherein the Mn—Zn-based ferrite has a spinel composition. And the composition ratio X of Ca and Si at point A where the concentration of Ca in the grain boundary existing between the particles is the maximum, and the Ca and Si at point B proceeding from point A toward the inside of the 5 nm particle. A ferrite core using Mn—Zn ferrite, wherein the composition ratio Y satisfies 0.5 ≦ X ≦ 1.0 and X + 0.05 ≦ Y ≦ X + 0.50. In addition to the Mn-Zn ferrite according to claim 1, Nb is 50 to 750 ppm in terms of Nb ₂ O ₅ , Co is 200 to 4000 ppm in terms of CoO, and Ti is TiO as a subsidiary component in a ratio to the weight of the main component. A ferrite core using Mn—Zn-based ferrite containing at least one of 100 to 6000 ppm in terms of _two . The electronic component comprised using the ferrite core of any one of Claim 1 and Claim 2 A power supply device comprising the electronic component according to claim 3.

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