JP3635411B2 - Magnetic ferrite manufacturing method, multilayer inductor component manufacturing method, composite multilayer component manufacturing method, and magnetic core manufacturing method - Google Patents

Description

【０１０４】
また、上記実施例および比較例のトロイダルコアについて、測定周波数４００ｋＨｚの条件にてのμおよびＱを求めた。その結果を表２に示した。
【０１０５】
【表２】

【０１０６】
表１および表２に示す結果から分かるように、粉砕ポット内の雰囲気を酸素分圧の高い雰囲気とすることにより、実施例のものは、比較例のものに比べて、良好な電磁気特性が得られた。
【０１０７】
また、表１および表２から分かるように、実施例３のように、出発原料のＣｕ成分として酸化銅の代わりに水酸化銅を用いることで、短時間（５時間）の配合混合時間でも各原料粉末が均一に分散され、磁気劣化の原因であったＣｕＯの偏析がなくなり、均一なフェライト組織が得られ、他の実施例と同様の特性が得られた。
【０１０８】
【発明の効果】
以上から明瞭なように、本発明によれば、良好な電磁気特性を持つ磁性フェライト、積層型インダクタ部品、ＬＣ複合部品等の複合積層部品及び磁心を得ることができる。
【図面の簡単な説明】
【図１】本発明の積層型インダクタの一例を示す断面図である。
【図２】上記積層型インダクタの一部破さい平面図である。
【図３】本発明の複合ＬＣ積層部品の一部を切り欠いて示した斜視図である。
【図４】結晶構造を示す図面代用写真であって、本発明の製造方法により製造されたインダクタチップ体のフェライト磁性層断面の透過電子顕微鏡写真である。
【図５】結晶構造を示す図面代用写真であって、比較例の製造方法により製造されたインダクタチップ体のフェライト磁性層断面の透過電子顕微鏡写真である。
【符号の説明】
１ 積層型インダクタ
２ 磁性体層
３ 導電体層
５ 外部電極
１０ チップ体
２０ 複合ＬＣ積層部品
CT コンデンサチップ体
IT インダクタチップ体
２１ セラミック誘電体層
２５ 内部電極
３１ セラミックス磁性層
３５ 内部導体
５１ 外部電極[0001]
[Industrial application fields]
The present invention relates to a method of manufacturing a magnetic ferrite, the method of manufacturing the multilayer inductor component, a manufacturing method of the production method and a magnetic core of the composite laminate components such as LC composite part.
[0002]
[Prior art]
Various ferrites are used as various electronic parts such as inductors and composite laminated parts because of their excellent magnetic properties.
[0003]
Multi-layer LC composite parts integrally form a capacitor chip body composed of a ceramic dielectric layer and an internal electrode layer, and an inductor chip body composed of a ferrite magnetic layer and an internal conductor. It is a thing.
[0004]
Such composite laminated parts are widely used in various electronic devices because of their small volume, high robustness and high reliability.
[0005]
These components, for example, LC composite components, were usually obtained by stacking and integrating the internal conductor paste, magnetic layer paste, dielectric layer paste and internal electrode layer paste by thick film technology, and then firing. The external electrode paste is printed or transferred onto the surface of the sintered body and then fired. In this case, Ni—Cu—Zn-based ferrite is generally used as the magnetic material used for the magnetic layer because it can be fired at a low temperature.
[0006]
Such a Ni—Cu—Zn based ferrite is manufactured as follows. As starting materials, usually NiO, CuO, ZnO, Fe ₂ O _{3 and the} like are used, and they are weighed in an appropriate amount and wet mixed by a ball mill or the like. What was wet-mixed in this way is usually dried by a spray dryer, and then calcined, and the calcined body is wet-pulverized to obtain a ferrite powder.
[0007]
In general, wet pulverization of the calcined body is a ball mill using a pot as a storage container and a metal ball as a pulverization medium, and the calcination body, the metal ball and normal water are pulverized in the pot. Grinding is performed with the dispersion medium added. At this time, in the conventional ball mill, the atmosphere in the pot is air.
[0008]
[Problems to be solved by the invention]
The Ni—Cu—Zn-based ferrite is generally manufactured as described above. For various electronic parts using the ferrite powder thus manufactured, the inductance L is further increased and the temperature characteristics of the inductance L are as follows. Further improvement is desired.
[0009]
Therefore, the present invention provides a method of manufacturing a magnetic ferrite capable of constituting an electronic component having an increased inductance L and improved temperature characteristics of the inductance L as compared with the prior art, a multilayer inductor component using the method, It aims at providing each manufacturing method of composite lamination parts, such as LC composite parts, and a magnetic core .
[0010]
Such an object is achieved by the present invention described in (1) to ( 7 ) below.
(1) Fe ₂ O ₃ : 45-50 mol%, NiO: 4-50 mol%, CuO: 3-30 mol% and ZnO: a method of producing a NiCuZn-based magnetic ferrite having a composition of 0.5-35 mol%, A method for producing magnetic ferrite, comprising a step of pulverizing a sintered body in a state where the interior is stored in a container having an oxygen partial pressure of 30% or more by volume.
(2) Fe ₂ O ₃ : 47.5 to 49.5 mol%, NiO: 5 to 45 mol%, CuO: 4.5 to 15.5 mol%, and ZnO: a method of producing a Ni-Zn-based magnetic ferrite having a composition of 1 to 31 mol%. A method for producing magnetic ferrite, comprising a step of pulverizing a calcined body of ferrite raw material powder in a container in an atmosphere having an oxygen partial pressure of 30% or more by volume.
(3) The air in the container is replaced with oxygen gas, or hydrogen peroxide (H ₂ O ₂ ) water is used as the dispersion medium for the pulverization , and the atmosphere in the container has an oxygen partial pressure higher than that of air. The manufacturing method of the magnetic ferrite as described in said (1) or (2) made into the atmosphere which has.
(4) The method for producing magnetic ferrite according to any one of the above (1) to (3), wherein copper hydroxide is used as a starting material for the Cu component contained in the ferrite raw material powder.
(5) A method of manufacturing an inductor component having an inductor portion configured by laminating a ferrite magnetic layer and an internal conductor layer, wherein the ferrite magnetic layer is any one of the above (1) to (4) A method of manufacturing a multilayer inductor component, characterized by being manufactured by the method described above.
(6) A method of manufacturing a composite laminated part having at least an inductor portion formed by laminating a ferrite magnetic layer and an internal conductor layer, wherein the ferrite magnetic layer is any one of the above (1) to (4) A method for producing a composite laminated part, characterized by being produced by the method according to claim 1.
(7) A method for producing a magnetic core composed of a magnetic ferrite sintered body obtained by firing magnetic ferrite, wherein the magnetic ferrite is described in any one of (1) to (4) above. A method of manufacturing a magnetic core, characterized by being manufactured by the method described above.
[0011]
[Action]
The inventors of the present invention have studied the relationship between the electromagnetic characteristics of an electronic component and the microstructure of the magnetic ferrite of the electronic component. As a result, in the transmission electron micrograph of the cross section of the magnetic ferrite layer, It has been found that when there is a stress fringe (interference fringe), there is a deterioration in inductance L and a deterioration in Q. Furthermore, as a result of examining the cause of the occurrence of stress fringes (interference fringes) in detail, CuO _x dissociated from the Ni—Cu—Zn-based ferrite is precipitated at the crystal grain boundaries, giving compressive stress to the ferrite particles, and distorting the lattice It was found that the stress fringes (interference fringes) were generated.
[0012]
In view of the above, various studies have been conducted to suppress the precipitation of CuO _{x at} the ferrite grain boundaries. As the oxygen partial pressure of the atmosphere in the ball mill pot increases, the CuO _x precipitation increases. Found to decrease.
[0013]
The present invention is based on this finding, and raises the oxygen partial pressure of the atmosphere in the pot above that of air to pulverize the calcined body.
[0014]
In addition, electronic components using a ferrite material in which the calcined body is pulverized under the condition that the oxygen partial pressure of the atmosphere in the pot is higher than that of air in this way are stress fringes (interference fringes) on the ferrite grain boundaries. ) Is extremely reduced as compared with the ferrite under the conventional conditions, and a good temperature characteristic can be obtained with a high inductance L.
[0015]
[Specific configuration]
Hereinafter, a specific configuration of the present invention will be described in detail.
[0016]
<Ferrite composition>
As the magnetic ferrite of the present invention, Ni—Cu—Zn based magnetic ferrite is used. The Ni—Cu—Zn based magnetic ferrite is not particularly limited and may be selected from various compositions depending on the purpose. Fe ₂ O ₃ : 45 to 50 mol%, particularly 47.5 to 49.5 mol%, NiO: 4 to 50 mol%, particularly 5 to 45 mol%, CuO: 3 to 30 mol%, particularly 4.5 to 15.5 mol%, and ZnO: 0.5 to 35 mol%, particularly 1 to 31 mol% are preferable.
[0017]
In addition, about 5 wt% or less of Co, Mn, or the like may be contained, and about 1 wt% or less of Ca, Si, Bi, V, Pb, or the like may be contained.
[0018]
Then, copper oxide or copper hydroxide is used as the Cu component of the starting material of the magnetic ferrite. Here, copper hydroxide includes both copper hydroxide (I) Cu (OH) and copper hydroxide (II) Cu (OH) ₂ .
[0019]
<Multilayer inductor>
1 and 2 show preferred examples of the multilayer inductor, that is, the multilayer inductor according to the present invention.
[0020]
The multilayer inductor 1 has a chip body 10 configured by alternately laminating and integrating magnetic layers 2 and conductor layers 3.
[0021]
The conductor layer 3 is formed in a pattern, and the adjacent conductor layers 3 are electrically connected to each other as shown in FIG. 2, thereby forming a coil.
[0022]
Furthermore, an external electrode 5 that is electrically connected to the conductor layer 3 is provided on the surface of the chip body 10.
[0023]
The outer shape and dimensions of the chip body 10 are not particularly limited and may be appropriately selected depending on the application. However, the outer shape is generally a rectangular parallelepiped shape, and the dimensions are (1.0 to 5.6) mm ×. What is necessary is just to set it as (0.5-5.0) x (0.6-1.9) mm.
[0024]
As a material of the magnetic layer 2 of the multilayer inductor 1, the Ni—Cu—Zn magnetic ferrite as described above is used. Ni-Cu-Zn-based magnetic ferrite is a low-temperature fired material. When such a magnetic layer is used, the multilayer inductor of the present invention does not generate a liquid phase during firing, and more in terms of electrical resistance. It will be excellent.
[0025]
Such a ferrite-based magnetic layer 2 can be formed by co-firing with a conductor layer paste described later at a firing temperature of 800 to 950 ° C., particularly 850 to 900 ° C.
[0026]
The thickness of the magnetic layer 2 after firing is not particularly limited, but usually the base thickness is about 250 to 500 μm, and the magnetic layer thickness between the conductor layers 3 and 3 is about 10 to 100 μm.
[0027]
As the material of the conductor layer 3, any conventionally known conductor layer material can be used.
[0028]
For example, Ag, Cu, Pd, or an alloy thereof may be used, and among these, Ag or an Ag alloy, particularly Ag is preferable.
[0029]
As the Ag alloy, an Ag—Pd alloy containing 95% by weight or more of Ag is suitable.
[0030]
Such a conductor layer 3 is formed by applying a conductor layer paste and baking it as will be described later.
[0031]
At this time, usually, voids are often formed in the conductor layer 3 by binder removal or the like.
[0032]
As shown in FIG. 2, the conductor layer 3 is normally arranged in a spiral shape in the magnetic layer 2, and both ends thereof are connected to a pair of external electrodes 5 and 5.
[0033]
In such a case, the winding pattern of the conductor layer 3, that is, the closed magnetic circuit shape, can be various patterns, and the number of turns, thickness, pitch, and the like may be appropriately selected according to the application.
[0034]
The thickness of the conductor layer 3 is usually about 5 to 30 μm, the winding pitch is usually about 40 to 100 μm, and the number of turns is usually about 1.5 to 50.5 turns.
[0035]
Further, the materials of the external electrodes 5 and 5 are not particularly limited, and various conductor materials, for example, printing films such as Ag, Ni, Cu, or alloys thereof such as Ag-Pd, plating films, vapor deposition films, and ions. A plating film, a sputtered film, or a laminated film thereof can be used.
[0036]
The thickness of the external electrodes 5 and 5 is arbitrary, and may be appropriately determined according to the purpose and application, but is usually about 5 to 30 μm.
[0037]
<Manufacturing method of multilayer inductor>
Next, the manufacturing method of the multilayer inductor according to the present invention will be described.
[0038]
First, a magnetic layer paste, a conductor layer paste, and an external electrode paste are manufactured.
[0039]
<Magnetic layer paste>
The magnetic layer paste is manufactured as follows.
[0040]
For example, in order to manufacture a ferrite paste, a predetermined amount of ferrite raw material powder such as NiO, ZnO, CuO, Fe ₂ O _{3 is} wet mixed by a ball mill or the like. The average particle size of each raw material powder to be used is usually about 0.1 to 10 μm.
[0041]
What was wet-mixed in this way is usually dried by a spray dryer or the like, and then calcined to form a calcined body. The calcined body is wet pulverized with a ball mill until the average particle size becomes about 0.01 to 0.1 μm, and dried with a spray dryer or the like.
[0042]
Here, the conditions of the wet grinding by the ball mill of the calcined body are as follows, for example.
Pot: Stainless steel ball mill Pot grinding medium: Dispersion medium at the time of steel ball grinding: Water pot atmosphere: atmosphere having a higher oxygen partial pressure than air The oxygen partial pressure is preferably 30% or more, particularly 70-100% by volume.
Grinding time: 40-70 hours
The obtained mixed ferrite powder, a binder such as ethyl cellulose and an acrylic resin, and a solvent such as terpineol and butyl carbitol are mixed and kneaded with, for example, three rolls to obtain a paste.
[0044]
In this case, various types of glass and oxides can be contained in the paste.
[0045]
In addition to the ferrite powder, various magnetic particles can be used.
[0046]
<Paste for conductor layer>
The conductor layer paste usually contains conductive particles, a binder, and a solvent.
[0047]
The material of the conductive particles is not particularly limited as long as it is conventionally used for a conductor layer paste, and a material that becomes a metal after firing such as metal or metal oxide may be used.
[0048]
In this case, the metal component is preferably a single metal containing one or more of Ag, Cu, Pd, or the like, or an alloy thereof.
[0049]
In particular, Ag, an Ag alloy, and an oxide thereof are preferable.
[0050]
The shape of the conductive particles is not particularly limited, but a substantially spherical shape is preferable. The average particle diameter D of the conductive particles is preferably 0.1 to 1 μm, particularly preferably 0.1 to 0.4 μm.
[0051]
If it is less than the above range, pasting is difficult and it is not suitable for printing.
[0052]
If the range is exceeded, a high-density conductor layer cannot be formed.
[0053]
In this case, in the present invention, it is preferable to use a conductive particle having a sharp particle size distribution.
[0054]
Specifically, when the average particle diameter of the conductive particles is D, it is preferable that particles having a particle diameter of D / 2 to 2D are present in an amount of 30% by weight or more, particularly 40% by weight or more.
[0055]
However, since it is difficult to make it too large, it is preferably 30 to 60% by weight, particularly 40 to 60% by weight.
[0056]
If it is less than the said range, a high-density conductor layer cannot be formed.
[0057]
Note that the particle diameter of the conductive particles may be calculated by observing with an SEM and converting the particle projection area into a circle.
[0058]
<Binder>
As the binder, any known binder such as ethyl cellulose, acrylic resin, butyral resin can be used.
[0059]
The binder content is usually about 1 to 5% by weight.
[0060]
As the solvent, any known solvents such as terpineol, butyl carbitol, and kerosene can be used.
[0061]
The solvent content is usually about 10 to 50% by weight. In addition, within a total range of about 10% by weight or less, if necessary, dispersants such as sorbitan fatty acid esters and glycerin fatty acid esters, plasticizers such as dioctyl phthalate, dibutyl phthalate, and butyl butyl phthalyl glycolate, and prevention of delamination For the purpose of suppressing sintering, various ceramic powders such as a dielectric, a magnetic material, and an insulator can be added.
[0062]
Each of these compositions is mixed and kneaded with, for example, a three roll to obtain a paste.
[0063]
In this case, in the production method of the present invention, the conductive particles are kneaded so as to be dispersed in the paste without excess or deficiency.
[0064]
Specifically, when the conductor layer paste after kneading is applied on a base material such as polyethylene terephthalate and the top surface of the coating film is observed with a 2000 to 10,000 times SEM image, The kneading is performed until the area ratio of the region where the conductive particles are not present on the outer surface is 20 to 60%, preferably 30 to 50%, particularly preferably 35 to 45%.
[0065]
In this case, the coating film outermost surface is a region of about 1 to 5 times the average particle diameter D of the conductive particles.
[0066]
If the range is less than or exceeds the range, the cross-sectional area ratio occupied by the conductor layer 3 in the gap 6 exceeds 85%, and the contact ratio between the magnetic layer 2 and the conductor layer 3 is 50%. Further, the porosity of the conductor layer 3 exceeds 50%.
[0067]
In order to obtain the conductor layer paste having the desired dispersibility, for example, the roll gap, viscosity, kneading time, etc. of the three rolls may be appropriately adjusted.
[0068]
The external electrode paste may be a normal paste containing the above-mentioned conductor material powder.
[0069]
Such a magnetic layer paste and a conductor layer paste are laminated by a printing method, a transfer method, a green sheet method, or the like.
[0070]
And after cut | disconnecting to a predetermined laminated body dimension, baking is performed.
[0071]
The firing conditions and firing atmosphere may be appropriately determined according to the material and the like, but are usually as follows.
[0072]
Firing temperature: about 850 to 950 ° C. Firing time: about 0.5 to 5 hours
Further, when Cu, Ni or the like is used for the conductor layer, a non-oxidizing atmosphere is used, and when Ag, Pd or the like is used, it may be in the air.
[0074]
<Composite laminated parts>
A multilayer ceramic LC composite component which is a preferred embodiment of the present invention is shown in FIG.
[0075]
The LC composite component 20 shown in FIG. 3 is configured by laminating a capacitor chip body CT formed by laminating a ceramic dielectric layer 21 and an internal electrode layer 25, a ceramic magnetic layer 31, and an internal conductor 35. Inductor chip body IT is integrated and has an external electrode 51 on the surface. Since the inductor chip body IT itself may be the same as the chip body 10 of the multilayer inductor 1, the description thereof is omitted here.
[0076]
<Capacitor chip body>
There are no particular limitations on the ceramic dielectric layer 21 of the capacitor chip body CT, and various dielectric materials may be used. However, it is preferable to use a titanium oxide-based dielectric because the firing temperature is low. In addition, titanic acid-based composite oxides, zirconic acid-based composite oxides, or a mixture thereof can also be used. Moreover, in order to reduce a calcination temperature, you may contain glass, such as borosilicate glass.
[0077]
Specifically, as the titanium oxide system, NiO, CuO, Mn ₃ O ₄ , Al ₂ O ₃ , MgO, SiO _2, etc., especially TiO ₂ containing CuO, etc. are used as titanic acid system complex oxides as necessary. _{is, BaTiO 3, SrTiO 3, CaTiO} 3, MgTiO 3 and mixtures thereof. Examples of the zirconate base composite _{oxides, BaZrO 3, SrZrO 3, CaZrO} 3, MgZrO 3 , and mixtures thereof, and the like.
[0078]
<Internal electrode layer>
In the present invention, the conductive material constituting the internal electrode layer 25 is not particularly limited, and is selected from Ag, Pt, Pd, Au, Cu, Ni, an alloy containing one or more of these, such as an Ag-Pd alloy, and the like. In particular, Ag alloys such as Ag and Ag—Pd alloys are suitable.
[0079]
<Structure>
The capacitor chip body CT of the LC composite component 1 may have a conventionally known structure, and the outer shape is generally a substantially rectangular parallelepiped shape. As shown in FIG. 1, one end of the internal electrode layer 25 is connected to the external electrode 51.
[0080]
The size of each part of the capacitor chip body CT is not particularly limited and may be appropriately selected depending on the application.
[0081]
The number of dielectric layers 21 may be determined according to the purpose, but is usually about 1 to 100. The thickness per layer of the dielectric layer 21 is usually about 20 to 150 μm, and the thickness per layer of the internal electrode layer 25 is usually about 5 to 30 μm.
[0082]
<Conductive material for external electrode>
There is no restriction | limiting in particular in the electrically conductive material which comprises the external electrode 51 of LC composite component 1 of this invention, For example, the alloy containing 1 or more types of these, such as Ag, Pt, Pd, Au, Cu, Ni, and Ag-Pd alloy However, Ag alloys such as Ag and Ag—Pd alloys are particularly suitable. Moreover, there is no restriction | limiting in particular in the shape, dimension, etc. of the external electrode 51, Although what is necessary is just to determine suitably according to the objective, a use, etc., thickness is about 100-2500 micrometers normally.
[0083]
<Structure of LC composite parts>
The dimension of the LC composite component 1 of the present invention is not particularly limited, and may be appropriately selected depending on the purpose and application, but is usually (2.0 to 10.0 mm) × (1.2 to 15.0 mm). It is about x (1.2-5.0 mm).
[0084]
<Magnetic core>
By using the magnetic ferrite of the present invention as the magnetic core material, a magnetic core having good characteristics can be obtained.
[0085]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.
[0086]
In the present specification, since the effect can be specified by the chip inductor, examples of the composite laminated component are omitted.
[0087]
The following pastes were prepared.
[0088]
(Paste for magnetic layer)
The starting materials were mixed so that the final composition was Fe ₂ O ₃ : 49 mol%, NiO: 8 mol%, CuO: 13 mol%, and ZnO: 30 mol%. These are wet-mixed for 16 hours using a ball mill, and then the wet mixture is dried by a spray dryer and calcined at 700 ° C. to form a calcined body. And wet pulverized.
[0089]
Pot: 4 inch, stainless ball mill pot grinding media: 1/2 inch steel ball 200 g
1/8 inch steel ball 600g
Dispersion medium during pulverization: 400 g of water
Atmosphere in the pot: O ₂ (air was replaced with O ₂ gas)
Calcined body: 200 g
Grinding time: 60 hours [0090]
The calcined body thus pulverized was dried with a spray dryer to obtain a Ni—Cu—Zn ferrite raw material powder having a final average particle size of 0.1 to 0.3 μm. Thus, a Ni—Cu—Zn ferrite raw material powder according to Example 1 of the present invention was obtained.
[0091]
On the other hand, the calcined body was wet-ground in the same manner as in Example 1 except that the atmosphere in the pot of the ball mill was left as air, thereby obtaining a Ni—Cu—Zn ferrite raw material powder of a comparative example.
[0092]
In addition, the calcined body is the same as in Example 1 except that hydrogen peroxide (H ₂ O ₂ ) water is poured into the pot of the ball mill instead of water to make the pot a system having a high oxygen partial pressure. Was obtained by wet pulverization, whereby the Ni—Cu—Zn ferrite raw material powder of Example 2 was obtained.
[0093]
Hydrogen peroxide is H ₂ O ₂ = H ₂ O + 1 / 2O ₂ due to the catalytic action of ferrite powder.
Thus, the atmosphere in the pot is changed to an O ₂ atmosphere. Here, since the internal pressure inside the pot becomes high due to the generation of O ₂ due to the above reaction, when hydrogen peroxide is used, the calculation of the internal pressure of the pot, the use of a high-strength grinding pot, the grinding pot with a leak valve structure Must be used.
[0094]
Further, in Example 1, Ni (Cu) Zn ferrite raw material was used in the same manner as in Example 1 except that Cu (OH) ₂ was used instead of CuO as a starting material, and the mixing and mixing time was reduced from 16 hours to 5 hours. I got a powder. This was designated as Example 3.
[0095]
Next, 3.84 parts by weight of ethyl cellulose and 78 parts by weight of terpineol were added to 100 parts by weight of these raw material powders, and the mixture was kneaded with three rolls to obtain a paste.
[0096]
(Paste for internal conductor)
2.5 parts by weight of ethyl cellulose and 40 parts by weight of terpineol were added to 100 parts by weight of Ag having an average particle size of 0.8 μm, and the mixture was kneaded with a three roll to obtain a paste.
[0097]
The magnetic layer paste and the internal conductor paste thus produced were printed and laminated to produce a laminated multilayer chip inductor.
[0098]
In this case, the firing temperature was 890 ° C., the firing time was 2 hours, and the firing atmosphere was in the air.
[0099]
The dimensions of the obtained multilayer chip inductor were 4.5 mm × 3.2 mm × 1.1 mm and the number of turns was 9.5 turns.
[0100]
Among the multilayer chip inductors described above, those using the magnetic ferrite of Example 1 and the magnetic ferrite of the comparative example were taken with a transmission electron microscope. Each photograph was shown as FIG. 4 and FIG. As can be seen from the photograph of FIG. 4, in the ferrite magnetic layer of Example 1, no stress fringes (interference fringes) are found at the ferrite grain boundaries, but as can be seen from the photograph of FIG. 5, the ferrite magnetic layer of the comparative example In, stress fringes (interference fringes) are observed at the ferrite grain boundaries.
[0101]
Moreover, the toroidal core was manufactured on the same baking conditions using the said ferrite raw material powder for a test. The toroidal core had an outer diameter of 11.1 mm, an inner diameter of 5.1 mm, a thickness of 2.4 mm, a winding number of 20 turns, and a wire diameter of 0.35 mm.
[0102]
About the said multilayer chip inductor, L (inductance) and Q on the conditions of the measurement frequency of 400 kHz were calculated | required. The obtained results are shown in Table 1.
[0103]
[Table 1]

[0104]
For the toroidal cores of the above examples and comparative examples, μ and Q were determined under the condition of a measurement frequency of 400 kHz. The results are shown in Table 2.
[0105]
[Table 2]

[0106]
As can be seen from the results shown in Table 1 and Table 2, by setting the atmosphere in the pulverization pot to an atmosphere having a high oxygen partial pressure, the examples have better electromagnetic characteristics than the comparison examples. It was.
[0107]
Moreover, as can be seen from Table 1 and Table 2, as in Example 3, by using copper hydroxide instead of copper oxide as the Cu component of the starting material, each of the mixing and mixing times in a short time (5 hours) The raw material powder was uniformly dispersed, the segregation of CuO which was the cause of magnetic deterioration was eliminated, and a uniform ferrite structure was obtained, and the same characteristics as other examples were obtained.
[0108]
【The invention's effect】
As is clear from the above, according to the present invention, it is possible to obtain a composite multilayer component such as a magnetic ferrite , a multilayer inductor component, an LC composite component and a magnetic core having good electromagnetic characteristics.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a multilayer inductor of the present invention.
FIG. 2 is a partially broken plan view of the multilayer inductor.
FIG. 3 is a perspective view in which a part of the composite LC laminated component of the present invention is cut away.
FIG. 4 is a drawing-substituting photograph showing a crystal structure, which is a transmission electron micrograph of a ferrite magnetic layer section of an inductor chip body manufactured by the manufacturing method of the present invention.
FIG. 5 is a drawing-substituting photograph showing a crystal structure, and is a transmission electron micrograph of a ferrite magnetic layer section of an inductor chip body manufactured by a manufacturing method of a comparative example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Multilayer inductor 2 Magnetic layer 3 Conductor layer 5 External electrode 10 Chip body 20 Composite LC multilayer component
CT capacitor chip body
IT inductor chip body 21 ceramic dielectric layer 25 internal electrode 31 ceramic magnetic layer 35 internal conductor 51 external electrode

Claims (7)

Fe ₂ O ₃ A method for producing a NiCuZn-based magnetic ferrite having a composition of: 45-50 mol%, NiO: 4-50 mol%, CuO: 3-30 mol% and ZnO: 0.5-35 mol%,
  A method for producing magnetic ferrite, comprising a step of pulverizing a calcined body of ferrite raw material powder in a container in an atmosphere having an oxygen partial pressure of 30% or more by volume. Fe ₂ O ₃ : 47.5 to 49.5 mol%, NiO: 5 to 45 mol%, CuO: 4.5 to 15.5 mol%, and ZnO: a method of producing a magnetic ferrite based on ZnO: 1 to 31 mol%. ,
  A method for producing magnetic ferrite, comprising a step of pulverizing a calcined body of ferrite raw material powder in a container in an atmosphere having an oxygen partial pressure of 30% or more by volume. The air in the container is replaced with oxygen gas, or hydrogen peroxide (H ₂ O ₂ The method for producing magnetic ferrite according to claim 1 or 2, wherein water is used and the atmosphere in the container is changed to an atmosphere having an oxygen partial pressure higher than that of air. The method for producing magnetic ferrite according to any one of claims 1 to 3, wherein copper hydroxide is used as a starting material for a Cu component contained in the ferrite raw material powder . A method of manufacturing an inductor component having an inductor portion configured by laminating a ferrite magnetic layer and an inner conductor layer,
A method of manufacturing a multilayer inductor component , wherein the ferrite magnetic layer is manufactured by the method according to any one of claims 1 to 4 . A method of manufacturing a composite multilayer component having at least an inductor portion formed by laminating a ferrite magnetic layer and an internal conductor layer,
The said ferrite magnetic layer is manufactured by the method in any one of Claims 1-4, The manufacturing method of the composite laminated component characterized by the above-mentioned . A method of manufacturing a magnetic core composed of a magnetic ferrite sintered body obtained by firing magnetic ferrite ,
A method for manufacturing a magnetic core, wherein the magnetic ferrite is manufactured by the method according to claim 1.

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