JP2003068518A - Powder for magnetic ferrite, method of manufacturing magnetic ferrite material, and method of manufacturing stacked ferrite part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide magnetic ferrite material excellent in voltage resistance and durability. SOLUTION: The magnetic ferrite material excellent in voltage resistance and durability can be provided by using power for magnetic ferrite which has Fe2 O3 by 40.0-51.0 mol%, CuO by 5.0-30.0 mol%, ZnO by 0.50-35.0 mol%, and NiO by 5.0-50.0 mol.% as main components, and includes Mn by 0.05-0.60 wt.% as a sub component and whose maximum grain diameter is 1.35 μm or under.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ferrite chip component such as a laminated chip bead and a laminated inductor, and a magnetic ferrite material and a laminated ferrite component used for a composite laminated component represented by an LC composite laminated component. It is about.

[0002]

2. Description of the Related Art Laminated chip ferrite parts and composite laminated parts (collectively referred to as laminated ferrite parts in this specification) are used for various electric devices because of their small volume and high reliability. Has been. This laminated ferrite component is usually obtained by laminating a sheet or paste for a magnetic layer made of magnetic ferrite and a paste for an internal electrode by a thick film laminating technique, and then sintering them to obtain a sintered body surface. It is manufactured by printing or transferring a paste for external electrodes on and then baking. It should be noted that the process of sintering after the layers are integrated is called simultaneous sintering. Since Ag or an Ag alloy is used as the material for the internal electrode due to its low resistivity, the magnetic ferrite material forming the magnetic layer can be co-sintered, in other words, having a melting point not higher than the melting point of Ag or the Ag alloy. Sintered at temperature (hereinafter, "low temperature sintering")
That is the case) is an absolute requirement. Therefore, in order to obtain a high density and high performance laminated ferrite component, the key is to be able to sinter the magnetic ferrite at a temperature equal to or lower than the melting point of Ag or an Ag alloy.

NiCuZn ferrite is known as a magnetic ferrite that can be sintered at a temperature below the melting point of Ag or an Ag alloy. For example, in JP-A-8-104561, Fe is converted to Fe ₂ O ₃ and 45.0 to 50.0 mo.
1%, Ni converted to NiO, 5.0 to 10.0 mol
%, Cu converted to CuO is 5.0 to 15.0 mol%,
Converting Zn into ZnO, 25.0 to 35.0 mol%, M
A magnetic ferrite containing 0.1 to 3.0 mol% of n converted to Mn ₃ O ₄ and 0.01 to 3.0 mol% of Li converted to Li ₂ O is disclosed. In addition, JP-A-8-
In 104562, Fe is converted to Fe ₂ O ₃ and the
5.0 to 50.0 mol%, Ni converted to NiO 1
5.0 to 30.0 mol%, Cu converted to CuO 8.
0 to 15.0 mol%, Zn converted to ZnO 15.0
˜25.0 mol%, Mn converted to Mn ₃ O ₄ and 0.10
The ～3.0Mol% and Li in terms of Li ₂ O 0.0
A magnetic ferrite containing 1 to 3.0 mol% is disclosed.

[0004]

Recently, in order to cope with high-density mounting, an example in which a plurality of internal electrodes are arranged in one laminated ferrite component has appeared. In the laminated ferrite component in which the plurality of internal electrodes are arranged, a potential difference (voltage) is generated between the internal electrodes, so that the ferrite material existing between the internal electrodes is required to have withstand voltage. Here, the withstand voltage property means that when a voltage is generated in the ferrite component, the ferrite material can withstand dielectric breakdown due to voltage application up to a higher voltage. However, the magnetic ferrite materials known so far have not been examined for such withstand voltage.
Further, it is desirable that NiCuZn ferrite has durability and can be suitably used for a long time. Therefore, an object of the present invention is to provide a magnetic ferrite material excellent in withstand voltage and durability and a laminated ferrite component using the magnetic ferrite material.

[0005]

Means for Solving the Problems The present inventor has conducted studies to improve the withstand voltage and durability of magnetic ferrite materials. As a result, they have found that when a predetermined amount of Mn is contained in a ferrite material having a predetermined composition, the withstand voltage property and durability can be improved, and further, the particle size of the pulverized powder after calcination varies depending on the Mn content. The present invention has been made based on the above findings, and provides the following magnetic ferrite powder for obtaining a magnetic ferrite having improved withstand voltage and durability. That is, the powder for magnetic ferrite of the present invention is Fe ₂ O ₃ : 40.0 to 51.0 m.
ol%, CuO: 5.0 to 30.0 mol%, ZnO: 0.
50-35.0 mol% and NiO: 5.0-50.0 m
ol% as a main component, Mn: 0.05 to 0.60 wt% as an accessory component, and the maximum particle size is 1.35 μm or less. In the powder of the present invention, the particle size is 1.0
It is desirable that the frequency of particles exceeding μm is 1.5% or less. Moreover, the content of Mn is 0.10 to 0.45 wt.
% Is desirable.

The present invention also provides a method for producing a magnetic ferrite material using the above magnetic ferrite powder.
That is, the manufacturing method of the magnetic ferrite material of the present invention is
_{e 2 O 3: 40.0~51.0mol%,} CuO: 5.0~3
0.0 mol%, ZnO: 0.50-35.0 mol% and NiO: 5.0-50.0 mol% as main components, M
n: A mixing step of mixing raw material powders containing 0.60 wt% or less (not including 0) as a sub-component, a calcination step of calcination of the mixed raw material powders, and a calcination obtained by the calcination step A pulverizing step for obtaining a pulverized powder having a maximum particle size of 1.35 μm or less, a forming step for obtaining a formed article using the pulverized powder obtained by the pulverizing step, and a formed article obtained by the forming step. And a sintering step of sintering.

Further, the present invention provides a method for manufacturing a laminated ferrite component using the above-mentioned powder for magnetic ferrite. That is, the present invention is a method for manufacturing a laminated ferrite component in which a magnetic layer and an internal electrode are laminated, and Fe ₂ O ₃ :
40.0-51.0 mol%, CuO: 5.0-30.0 m
ol%, ZnO: 0.50-35.0 mol% and Ni
O: 5.0 to 5.0 mol% as a main component, Mn: 0.6
A raw material powder containing 0 wt% or less (not including 0) as a subcomponent is mixed, the mixture is calcined at a temperature of 900 ° C. or less, and the calcined body obtained by calcining is pulverized to obtain the maximum particle size. Of 1.35 μm or less is obtained, and then the magnetic layer material manufacturing process for obtaining a sheet or paste for forming a magnetic layer using the pulverized powder, and the sheet or paste and the material for the internal electrode are alternately laminated. The method is characterized by including a step of obtaining a laminated compact and a step of sintering the laminated compact at a temperature of 940 ° C. or lower.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION First, the reasons for limiting the composition of the present invention will be explained. The amount of Fe ₂ O ₃ has a great influence on the magnetic permeability. When Fe ₂ O ₃ is less than 40.0 mol%, the magnetic permeability is small, and the magnetic permeability increases as it approaches the stoichiometric composition as ferrite, but sharply decreases with the stoichiometric composition as a peak. Therefore, the upper limit is 5
It is set to 1.0 mol%. The desirable amount of Fe ₂ O ₃ is 45.0.
˜49.8 mol%, more desirable amount of Fe ₂ O ₃ is 4
It is 9.2 to 49.8 mol%. CuO is a compound that contributes to the reduction of the sintering temperature in the present invention and is 5.0 mo.
If it is less than 1%, sintering cannot be realized in a temperature range below the melting point of Ag. However, if it exceeds 30.0 mol%, the specific resistance of ferrite decreases and the quality factor Q deteriorates, so it is set to 5.0 to 30.0 mol%. A desirable CuO amount is 5.0 to 25.0 mol%, and a more desirable CuO amount is 5.0 to 20.0 mol%.

The magnetic permeability μ can be improved by decreasing NiO or increasing ZnO, but if the amount of ZnO is too large, the Curie temperature becomes 100 ° C. or lower, and the temperature characteristics required for electronic parts cannot be satisfied. . Therefore, the amount of ZnO is 0.50-35.0 mol%.
A desirable ZnO amount is 15.0 to 30.0 mol%, and a more desirable ZnO amount is 18.0 to 25.0 mol%.
Further, the NiO amount is set to 5.0 to 5.0 mol%. A desirable amount of NiO is 5.0 to 45.0 mol%, and a more desirable amount of NiO is 7.0 to 35.0 mol%. The magnetic characteristics of the magnetic ferrite have a very strong composition dependency, and in a region outside the above composition range, the magnetic permeability μ and the quality factor Q become low, and it becomes unsuitable as a magnetic material for a laminated ferrite component.

Next, the magnetic ferrite material according to the present invention contains Mn as an accessory component. The amount of Mn is 0.0 in terms of Mn.
It is 5 to 0.60 wt%. It is based on the finding that when Mn is in this range, the withstand voltage property and the durability are excellent. A desirable Mn amount is 0.10 to 0.45 wt%, and a more desirable Mn amount is 0.20 to 0.40 wt%.
Here, "converted to Mn" means the amount contained as pure Mn regardless of the form existing in the sintered body. For example,
Even when it is contained as Mn oxide, it does not mean the amount as Mn oxide, but M which constitutes Mn oxide.
It means the amount of n.

The magnetic ferrite powder of the present invention has a maximum particle size of 1.35 μm or less. This means that the magnetic ferrite powder of the present invention does not contain coarse particles exceeding 1.35 μm. As shown in Examples described later, there is a relation between the amount of Mn and the particle size of the pulverized powder, and when a powder having a maximum particle size of 1.35 μm or less is used, excellent voltage resistance and durability can be obtained. You can The maximum particle size is preferably 1.20 μm or less, more preferably 1.10 μm or less. In the powder for magnetic ferrite of the present invention,
The ratio (frequency) of particles having a particle size of more than 1.0 μm in the powder is preferably 1.5% or less. This means that there are few particles of relatively large size. The frequency of particles above 1.0 μm is preferably 1.0
% Or less, and more preferably 0.5% or less.

Next, a method of manufacturing the magnetic ferrite material according to the present invention will be described in the order of each step. As the raw material powder, for example, Fe ₂ O ₃ powder, CuO powder, ZnO powder and Ni
Prepare O powder. These powders are powders which are the main components of the magnetic ferrite material having excellent withstand voltage of the present invention.
In addition to these powders which are the main components, Mn which is an accessory component
The raw material powder for is prepared. For Mn, Mn
Oxides (eg Mn ₂ O ₃ , Mn ₃ O ₄ ) or Mn
A powder made of a carbonate (for example, MnCO ₃ ) is the raw material powder. However, this is just one aspect,
As long as Mn is contained in the sintered body in the range of 0.05 to 0.60 wt% in terms of Mn, the mode of addition thereof is not limited. The particle size of each raw material powder to be prepared may be appropriately selected within the range of 0.1 to 10 μm. Further, the prepared raw material powders are wet-mixed using, for example, a ball mill. Although the mixing depends on the operating conditions of the ball mill, a uniform mixed state can be obtained after about 20 hours.

After mixing the raw material powders, calcination is performed.
The calcination temperature is 850 ° C. or lower. That is, if the calcining temperature exceeds 850 ° C., the calcined body becomes hard,
This is because it becomes difficult to obtain the particle size distribution of the powder that enables sintering in the temperature range below the melting point of Ag. A desirable calcination temperature is 650 to 750 ° C. Calcination time is 5
It may be appropriately selected within a range of up to 15 hours. After the calcination, the calcined body is crushed. The specific surface area of the pulverized powder is 6 m ² / g
It is important for the sintering in the temperature range below the melting point of Ag to be about the above. In order to obtain such a fine powder, the crushing conditions may be controlled, but it is also possible to collect the powder having such a particle size distribution from the crushed powder without particularly controlling the conditions. When using a ball mill, pulverization requires about 60 to 80 hours. After adding a binder or the like to the pulverized powder obtained above, it is molded into a predetermined shape,
After that, it is subjected to sintering.

Next, the multilayer ferrite component of the present invention will be described by taking a multilayer chip inductor array as an example. 1 to 3 are views showing a multilayer chip inductor array 1, FIG. 1 is a plan view thereof, FIG. 2 is an AA sectional view of FIG. 1, and FIG. 3 is a BB sectional view of FIG. . As shown in FIGS. 1 to 3, a multilayer chip inductor array 1 includes a chip body 5 having a multi-layer structure in which magnetic ferrite layers 2 and internal electrodes 3 are alternately laminated, and the chip body 5 is internally provided at both ends thereof. It is composed of an electrode 3 and an external electrode 6 arranged so as to be electrically connected via the extraction electrode 4. The multilayer chip inductor array 1 includes four independent internal electrodes 3 in one chip body 5. When a plurality of internal electrodes 3 are provided in this manner, a potential difference is generated between the adjacent internal electrodes 3 during use, so that withstand voltage is required. That is, when the present invention is applied to a laminated ferrite component having a plurality of independent internal electrodes 3, the effect can be sufficiently enjoyed. The magnetic ferrite material according to the present invention is used for the magnetic ferrite layer 2. That is, magnetic ferrite powder having a predetermined composition is kneaded together with a binder and a solvent to obtain a paste for forming the magnetic ferrite layer 2. This paste and the paste for forming the internal electrode 3 and the extraction electrode 4 are alternately printed, laminated, and then sintered to obtain an integrated chip body 5. As the binder, known binders such as ethyl cellulose, acrylic resin and butyral resin can be used. As the solvent, known solvents such as terpineol, butyl carbitol, kerosene can be used. There is no limit to the amount of binder and solvent added. However, it is recommended that the binder content be in the range of 1 to 5 parts by mass and the solvent content be in the range of 10 to 50 parts by mass. In addition to the binder and the solvent, a dispersant, a plasticizer, a dielectric material, an insulating material and the like can be added in a range of 10 parts by mass or less. As the dispersant, sorbitan fatty acid ester or glycerin fatty acid ester can be added. As a plasticizer,
Dioctyl phthalate, dibutyl phthalate, butyl butyl phthalyl glycolate can be added.

The magnetic ferrite layer 2 can also be formed by using a magnetic ferrite layer sheet. That is, a powder having a predetermined composition according to the present invention is kneaded in a ball mill together with a binder containing polyvinyl butyral as a main component and a solvent such as toluene or xylene to obtain a slurry. This slurry can be applied onto a film such as a polyester film by, for example, a doctor blade method and dried to obtain a magnetic ferrite layer sheet. This magnetic ferrite layer sheet is alternately laminated with the paste for the internal electrodes 3 and then sintered to obtain the chip body 5 having a multilayer structure. The amount of binder is not limited, but 1-5
It is recommended to use the range of parts by mass. Also, a dispersant,
It is also possible to add a plasticizer, a dielectric material, an insulating material and the like in a range of 10 parts by mass or less.

The internal electrode 3 has a small resistivity Ag or Ag in order to obtain a quality factor Q practical for an inductor.
It is desirable to use an alloy such as an Ag-Pd alloy.
However, the present invention is not limited to this, and Cu, Pd, or an alloy thereof may be used. The paste for obtaining the internal electrode 3 is a powder of Ag or Ag alloy, or a powder of these oxides mixed with a binder and a solvent,
It can be obtained by kneading. As the binder and the solvent, the same ones as those used in the paste for forming the magnetic ferrite layer 2 can be applied. Each layer of the internal electrode 3 has an oval shape, and each layer of the internal electrode 3 adjacent to each other in the thickness direction has a spiral shape to ensure continuity, and thus forms a closed magnetic circuit coil (winding pattern). The material of the external electrode 6 is Ag, Ni, C
Known materials such as u and Ag-Pd alloy can be used. The external electrode 6 can be formed of these materials by various methods such as a printing method, a plating method, a vapor deposition method, an ion plating method, and a sputtering method.

The size of the chip body 5 of the multilayer chip inductor array 1 is not particularly limited. It can be appropriately set according to the application. Generally, the outer shape is a substantially rectangular parallelepiped shape, and the dimensions are 1.0 to 4.5 mm x 0.5 to 3.2.
Most of them are in the range of mm × 0.6 to 1.9 mm. Further, there is no particular limitation on the inter-electrode thickness and the base thickness of the magnetic ferrite layer 2, and the inter-electrode thickness is 10 to 100 μm,
The base thickness can be set to about 250 to 500 μm. Further, the thickness of the internal electrode 3 itself is usually 5 to
The pitch can be set in the range of 30 μm, the pitch of the winding pattern can be 10 to 100 μm, and the number of turns can be about 1.5 to 20.5 turns.

The sintering temperature after alternately stacking the paste or sheet for the magnetic ferrite layer 2 and the paste for the internal electrode 3 is 940 ° C. or lower. This is because if the temperature exceeds 940 ° C., the material forming the internal electrodes 3 may diffuse into the magnetic ferrite layer 2 and the magnetic characteristics may be significantly deteriorated. Although the magnetic ferrite of the present invention is suitable for low temperature sintering, sintering is insufficient at temperatures below 800 ° C. Therefore, it is desirable that the sintering be performed at 800 ° C. or higher. The desirable sintering temperature is 820 to 930 ° C, and more desirably 875 to 920 ° C. The sintering time may be set within the range of 0.05 to 5 hours, preferably 0.1 to 3 hours.

Next, an LC composite component which is an embodiment of the LC composite laminated component will be described. FIG. 4 is a schematic sectional view of the LC composite component 11. As shown in FIG. 4, the LC composite component 11 is one in which the chip capacitor portion 12 and the chip ferrite portion 13 are integrated. The chip capacitor section 12 includes a ceramic dielectric layer 21 and internal electrodes 22.
Has a multi-layer laminated structure in which and are alternately laminated. A potential difference may occur between the internal electrodes 22, which may cause dielectric breakdown. The material of the ceramic dielectric layer 21 is not limited, and various conventionally known dielectric materials can be used. In the present invention, a titanium oxide-based dielectric material having a low sintering temperature is desirable, but a titanic acid-based composite oxide, a zirconic acid-based composite oxide, or a mixture thereof can be used. Further, various glasses such as borosilicate glass may be added to lower the sintering temperature. As the internal electrodes 22, the multilayer chip inductor array 1 described above is used.
The same material as that of the internal electrode 3 can be used. Each internal electrode 22 is electrically connected to another external electrode 15 alternately.

The chip ferrite portion 13 is composed of a laminated chip inductor in which magnetic ferrite layers 32 and electrode layers 33 are alternately laminated. This basic configuration is the same as that of the multilayer chip inductor array 1 described above.
Therefore, detailed description thereof is omitted here. The dimension of the LC composite component 11 is not limited, as in the case of the multilayer chip inductor array 1 described above. Therefore,
It can be appropriately set according to the application. Usually, it has a nearly rectangular parallelepiped shape and is 1.6 to 10.0 mm x 0.8 to 15.
It has a size of about 0 mm × 1.0 to 5.0 mm.

[Examples] The present invention will be described below based on specific examples. Fe ₂ O ₃ powder having an average particle size of 0.22 μm, CuO powder having an average particle size of 0.91 μm, ZnO powder having an average particle size of 0.55 μm, and an average particle size of 0.32 μ
m NiO powder and Mn ₃ O ₄ having an average particle size of 0.44 μm
Prepare the powder and according to the following mixing-grinding conditions, Table 1
Seven kinds of pulverized powders having the composition shown in were obtained. Among the above-mentioned raw material powders, Fe ₂ O ₃ powder, CuO powder, ZnO powder and NiO powder are main components, and Mn ₃ O ₄ is a subcomponent.
In Table 1, the Mn content is a converted value.

[0022]

[Table 1]

[Mixing-grinding conditions] Mixing and grinding pot: stainless ball mill pot Mixing and grinding media: steel balls Mixing time: 16 hours Calcination conditions: 700 ° C x 10 hours Grinding time: 72 hours

The particle size distribution of each of the obtained pulverized powders was measured by HRA manufactured by Microtrack Co., Ltd. The results are shown in Table 2. In addition, Table 2 also shows the Mn content in each pulverized powder. As shown in Table 2, powder with a low Mn content of 0.02 wt% (No. 1), conversely 0.6
The powder (No. 8) with a large amount of 3 wt% has a particle size of 1.38 μm
Particles were observed. On the other hand, the Mn content is 0.
In the ground powder of 08 wt% (No. 2) to 0.54 wt% (No. 7), particles having a particle size of 1.38 μm were not observed. That is, when the Mn content exceeds 0.02 wt% and less than 0.63 wt%, the maximum particle size is 1.38μ.
Since it was less than m, it became clear that there was a relationship between the Mn content and the particle size distribution of the pulverized powder. In addition, the value of the maximum particle size observed by the particle size distribution measurement is shown in Table 1. In addition, based on the result of particle size distribution measurement, 1.0
The frequency occupied by particles having a particle size of more than μm and the average particle size were calculated. The results are shown in Tables 1 and 2.

Using these powders, a multilayer capacitor was prepared under the following conditions, and the insulation resistance (IR) and breakdown voltage (VB) were measured and the accelerated life test (HALT) was performed. Further, the magnetic permeability (μ) and quality factor (Q) were measured under the following conditions. The results are shown in Table 1.

[0026]

[Table 2]

As shown in Table 1, the maximum particle size is 1.38μ.
The insulation resistance (IR) of the multilayer capacitor made using the pulverized powder (No. 1 and 8) containing m particles is 1
The maximum particle size is 1.3 μm, while it is as low as 00 MΩ or less.
Multilayer capacitors made using the following pulverized powders (No. 2 to 7) show an insulation resistance (IR) of about 500 MΩ or more. Especially, No. 4 and 5 are 1
It is noted that it exhibits an insulation resistance (IR) of 0000 MΩ or more. Next, focusing on the breakdown voltage (VB), the maximum particle size is 1 in comparison with the multilayer capacitor made using the pulverized powder (No. 1 and 8) containing particles having the maximum particle size of 1.38 μm. The multilayer capacitor made using pulverized powder (No. 2 to 7) of 0.3 μm or less exhibits a high breakdown voltage (VB). Further, the accelerated life test (HALT) shows the same tendency as the insulation resistance (IR) and the breakdown voltage (VB). That is, a pulverized powder (N with a maximum particle size of 1.38 μm)
o.1 and 8), the pulverized powder with a maximum particle size of 1.3 μm or less (No.
2-7) has a long accelerated life.

As described above, there is a relationship between the maximum particle size of pulverized powder and the insulation resistance (IR), breakdown voltage (VB) and accelerated life. Good insulation resistance (I
R), breakdown voltage (VB) and accelerated life can be obtained. In particular, when the maximum particle size is 1.2 μm or less, and further 1.0 μm or less, more desirable insulation resistance (IR), breakdown voltage (VB) and accelerated life can be obtained. Further, Table 1 shows the frequency of particles having a particle size of more than 1.0 μm, but the maximum particle size is 1.3 μm or less, and the frequency is 1.5% or less.
Furthermore, the multilayer capacitor produced by using 1.0% or less of pulverized powder has good insulation resistance (IR), breakdown voltage (VB) and accelerated life. Therefore, 1.
It has also been found that controlling the frequency of particles occupying a size above 0 μm is important for obtaining good insulation resistance (IR), breakdown voltage (VB) and accelerated life. Also,
Table 1 shows the magnetic permeability (μ) and quality factor (Q) of the sintered body using the pulverized powder (No. 2 to 6) having good insulation resistance (IR), breakdown voltage (VB) and accelerated life. like,
The value has no problem in practical use.

[Specifications of Multilayer Capacitor] 2.5 parts by mass of ethyl cellulose and 40 parts by mass of terpineol were added to 100 parts by mass of each powder having the composition shown in Table 1 and kneaded with a three-roll mill to prepare a magnetic ferrite layer. The paste was adjusted. On the other hand, to 100 parts by mass of Ag having an average particle diameter of 0.8 μm, 2.5 parts by mass of ethyl cellulose and 40 parts by mass of terpineol were added and kneaded with a three-roll to obtain an internal electrode paste. After the magnetic ferrite layer paste and the internal electrode paste are alternately printed and laminated, 8
Sintering was performed at 90 ° C. for 2 hours to obtain a multilayer chip capacitor 41 having the form shown in FIGS. 5 and 6. Note that FIG.
6 is a side sectional view of the multilayer chip capacitor 41 and a sectional view taken along line CC of FIG. 6 and FIG. 5. As shown in FIGS. 5 and 6, the multilayer chip capacitor 41 includes a chip body 44 having a multilayer structure in which magnetic ferrite layers 42 and internal electrodes 43 are alternately laminated, and internal electrodes at both ends of the chip body 44. External electrode 45 arranged so as to be electrically connected to 43
Composed of and. The size of the multilayer chip capacitor 41 is 3.2 mm × 1.6 mm × 1.1 mm, the number of layers of the internal electrodes 43 is four, and the thickness of the magnetic ferrite layer 42 between the internal electrodes 43 adjacent in the stacking direction is set. D (see FIG. 6)
Was 50 μm. The external electrode 45 was formed by baking Ag at 600 ° C.

[Breakdown voltage (VB)] An automatic step-up breakdown tester (THK-2011 ADMP) manufactured by Tama Densoku Co., Ltd. was used for the manufactured multilayer chip capacitor 41 to obtain 100.
The voltage was continuously applied at a speed of V / sec., And the voltage at which the multilayer chip capacitor 41 was dielectrically broken down was measured. [Insulation Resistance (IR)] A voltage of 10 V was applied to the manufactured multilayer chip capacitor 41 for 15 seconds, and the insulation resistance after 1 minute was measured using a resistance measuring device (HP4329A) manufactured by Hewlett-Packard Co. .

[Accelerated Life Test] Twenty prepared multilayer chip capacitors 41 were prepared and subjected to 10 at 200 ° C.
A voltage of 0V was applied for 48 hours. The average life was determined by the Weibull analysis shown below. From the Weibull distribution function R = exp [-(t / η) ^m ] (where R: residual rate, t: failure time), the scale parameter η and the residual parameter m are obtained, and the average life τ is τ = η Γ ( 1 + 1 / m) (where Γ: gamma function).

[Magnetic permeability (μ), quality factor (Q)] A toroidal sintered body sample was prepared. A copper wire (wire diameter: 0.35 mm) was wound around this sample for 20 turns, and the inductance was measured using a LCR meter (HP4192A manufactured by Hewlett-Packard Co., Ltd.) at a measurement frequency of 100 kHz and a measurement current of 0.2 mA. Then, the magnetic permeability (μ) was obtained using the following formula. Regarding the quality factor (Q), the real number μ ′ and the imaginary number μ ″ of the complex magnetic permeability are calculated to obtain Q
(Quality coefficient) = μ '/ μ ". Permeability μ = (le × L) / (μ ₀ × Ae × N ² ) le: Magnetic path length L: Sample inductance μ ₀ : Vacuum permeability = 4π × 10 ⁻⁷ (H / m) Ae:
Cross-sectional area of sample N: Number of coil turns

[0033]

As described above, according to the present invention, it is possible to provide a magnetic ferrite material having excellent voltage resistance and durability and a laminated ferrite component using the magnetic ferrite material.

[Brief description of drawings]

FIG. 1 is a plan view of a multilayer chip inductor array according to this embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is an LC composite component according to the present embodiment.

FIG. 5 is a side sectional view of a multilayer chip capacitor used in an example.

FIG. 6 is a sectional view taken along line CC of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multilayer chip inductor array, 2 ... Magnetic ferrite layer, 3 ... Internal electrode, 4 ... Extraction electrode, 5 ... Chip body,
6 ... External electrode, 11 ... LC composite part, 12 ... Chip capacitor part, 13 ... Chip ferrite part, 15 ... External electrode, 21 ... Ceramics dielectric layer, 22 ... Internal electrode, 3
2 ... Magnetic ferrite layer, 33 ... Electrode layer, 41 ... Multilayer chip capacitor, 42 ... Magnetic ferrite layer, 43 ... Internal electrode, 44 ... Chip body, 45 ... External electrode

Continued front page    F-term (reference) 4G002 AA07 AA10 AB01 AE05                 4G018 AA23 AA24 AA25 AB09 AC03                       AC12 AC16                 5E041 AA11 AB01 AB02 BD01 CA01                       HB01 HB03 HB17 NN01 NN06                       NN18

Claims (5)

[Claims] 1. Fe ₂ O ₃ : 40.0-51.0 mol%,
CuO: 5.0-30.0 mol%, ZnO: 0.50-3
It is characterized by having 5.0 mol% and NiO: 5.0 to 50.0 mol% as main components, Mn: 0.50 to 0.60 wt% as an accessory component, and having a maximum particle size of 1.35 μm or less. Powder for magnetic ferrite. 2. The powder for magnetic ferrite according to claim 1, wherein the frequency of particles having a particle size of more than 1.0 μm is 1.5% or less. 3. The content of Mn as an accessory component is 0.10.
The powder for magnetic ferrite according to claim 1 or 2, wherein the content is 0.45 wt%. 4. Fe ₂ O ₃ : 40.0-51.0 mol%,
CuO: 5.0-30.0 mol%, ZnO: 0.50-3
Main components are 5.0 mol% and NiO: 5.0 to 50.0 mol%, and Mn: 0.60 wt% or less (0 is not included).
A mixing step of mixing raw material powders containing as a sub-component, a calcination step of calcining the mixed raw material powders, and a calcination body obtained by the calcination step being crushed to have a maximum particle size of 1. A pulverization step of obtaining a pulverized powder of 35 μm or less, a molding step of obtaining a compact by using the pulverized powder obtained by the pulverization step, and a sintering step of sintering the compact obtained in the molding step,
A method for producing a magnetic ferrite material, comprising: 5. A method for manufacturing a laminated ferrite component in which a magnetic layer and an internal electrode are laminated, wherein Fe ₂ O ₃ : 40.0 to 51.0 mol% and CuO: 5.0.
30.0 mol%, ZnO: 0.50-35.0 mol%
And NiO: 5.0 to 50.0 mol% as a main component,
Mixing raw material powder containing Mn: 0.60 wt% or less (not including 0) as a sub-component, calcining this mixture at a temperature of 900 ° C. or less, and crushing the calcined body obtained by calcining. To obtain a pulverized powder having a maximum particle size of 1.35 μm or less, and then to obtain a sheet or paste for forming a magnetic layer using the pulverized powder. A method for producing a laminated ferrite component, comprising: a step of alternately laminating to obtain a laminated molded body; and a step of sintering the laminated molded body at a temperature of 940 ° C. or lower.