JP2001176718A - Laminated ferrite component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated ferrite component where deterioration of magnetic characteristics, in particular of permeability μ to stress is low, and low temperature baking, i.e., baking at a temperature lower than or equal to the melting point of Ag or Ag alloy which are used as electrode material becomes possible. SOLUTION: A powder for magnetic ferrite has a composition of Fe2O3 of 40-51 mol%, 5-30 mol% CuO, 0.5-35 mol% ZnO and 5-50 mol% MgO and the peak position of particle size distribution is in a rage of 0.3-1.2 μm. The laminated ferrite component is manufactured by using the powder. Since the magnetostriction constant of the above MgCuZn ferrite is 10×10-6, deterioration in permeability μ is small. The powder which has a peak position of particle size distribution in the range of 0.3-1.2 μm is used, so that baking simultaneous with internal electrodes composed of Ag or Ag alloy is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Laminated chip ferrite parts and composite laminated ferrite parts (collectively referred to as laminated ferrite parts in this specification) are used in various electric devices because of their small volume and high reliability. Have been. This laminated ferrite component is usually formed by laminating and integrating 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. It is manufactured by printing or transferring an electrode paste and then baking. Note that firing after lamination and integration is called simultaneous firing. Since Ag or Ag alloy is used as the material for the internal electrode because of its low resistivity, the magnetic ferrite material constituting the magnetic layer can be co-fired, in other words, it has a melting point lower than the melting point of Ag or Ag alloy. An absolute condition is that firing can be performed at a temperature. Therefore, in order to obtain a high-density, high-characteristic laminated ferrite component, the key is to sinter the magnetic ferrite at a low temperature equal to or lower than the melting point of Ag or an Ag alloy.

[0003] NiCuZn ferrite is known as a magnetic ferrite that can be fired at a low temperature equal to or lower than the melting point of Ag or an Ag alloy. That is, the specific surface area is reduced to 6 by pulverization.
NiCuZn using raw material powder of about m ² / g or more
Ferrite can be fired at a temperature equal to or lower than the melting point of Ag (960 ° C.), and is therefore widely used in multilayer ferrite parts.
However, NiCuZn ferrite has a magnetic property, particularly a magnetic permeability μ, which is sensitive to external stress and thermal shock (for example, “Powder and Powder Metallurgy” vol. 39,8, 612-617 (1
992)), the following problems occur when manufacturing laminated ferrite parts. In other words, the stress caused by barrel polishing and plating performed in the manufacturing process, the stress resulting from the difference in linear expansion coefficient between the magnetic layer and the internal electrode, and the stress generated during mounting on a printed circuit board, deteriorate the magnetic permeability μ, The problem is that the inductance L deviates from the design value. To solve this problem, the present inventor has already
Has made two proposals. One is that the magnetic layer and the internal electrode are opposed to each other via a gap (Japanese Patent Application Laid-Open No. 4-65807). This proposal aims to avoid the stress caused by the difference in linear expansion coefficient between the magnetic layer and the internal electrode. The other is to make Bi exist in the crystal grain boundaries of NiCuZn ferrite to generate tensile stress in the crystal grains after firing, thereby making the magnetic properties less sensitive to external stress (Japanese Unexamined Patent Publication No. -223414). The above two proposals are effective methods for reducing the magnetic properties of NiCuZn ferrite due to stress.

[0004]

By the way, NiCuZ
Since the raw material NiO is expensive, n-ferrite naturally becomes an expensive material. Therefore, N
MgO, Mg (OH) ₂ or MgC which is cheaper than iO
Attention has been paid to MgCuZn ferrite using O ₃ , and various improvements have been made. For example, JP-A-10-3245
No. 64 proposes that the amount of B (boron) contained in MgCuZn ferrite be 2 to 70 ppm. However, Japanese Patent Application Laid-Open No. 10-324564
According to the example, the MgCuZn ferrite disclosed in the publication is fired at 1200 ° C., so that it is difficult to apply the MgCuZn ferrite to a laminated ferrite component to which the present invention is directed. Ag or A which is an electrode material
This is because simultaneous firing with the g alloy cannot be performed. Japanese Patent No. 2747403 also discloses a magnetic ferrite containing MgO, but there is no description of firing conditions, and it is determined that simultaneous firing is not satisfied. Accordingly, the present invention provides a laminated ferrite component that has a small deterioration in magnetic properties with respect to stress, particularly magnetic permeability μ, and that can be fired at a low temperature, that is, fired at a temperature equal to or lower than the melting point of Ag or an Ag alloy used as an electrode material. As an issue.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a magnetic ferrite layer and an internal electrode which are alternately laminated, and an external electrode electrically connected to the internal electrode. Wherein the magnetic ferrite layer is made of a magnetic ferrite sintered body having a magnetostriction constant of 10 × 10 ⁻⁶ or less, and the internal electrode is made of Ag or an Ag alloy. Provide multilayer ferrite parts. In this laminated ferrite part, the magnetic ferrite fired body is Fe
₂ O ₃ : 40-51 mol%, CuO: 5-30 mol%, Zn
It is desirable to use MgCuZn-based ferrite having a composition of O: 0.5 to 35 mol% and MgO: 5 to 50 mol%.

According to the present invention, a laminated inductor portion in which magnetic ferrite layers and internal electrodes are alternately laminated, and a laminated capacitor portion in which dielectric layers and internal electrodes are alternately laminated are integrated. And a multilayer ferrite component having an internal electrode of the multilayer inductor section and an external electrode electrically connected to the internal electrode of the multilayer capacitor section, wherein the magnetic ferrite layer of the multilayer inductor section has a magnetostriction constant of 10%. A laminated ferrite component is provided, which is constituted by a sintered body of a MgCuZn-based magnetic ferrite of × 10 ^-6 or less, and wherein the external electrode is constituted by Ag or an Ag alloy. In this laminated ferrite component, the MgCuZn-based magnetic ferrite fired body includes:
_{Fe 2 O 3: 45~49.8mol%,} CuO: 7~30mol
%, ZnO: 15 to 25 mol%, MgO: 5 to 35 mol%
It is desirable to use MgCuZn-based ferrite having the following composition. In addition, as the MgCuZn-based magnetic ferrite fired body, Fe ₂ O ₃ : 45 to 49.8 mol%, Cu
O: 7 to 30 mol%, ZnO: 15 to 25 mol%, MgO
+ NiO: The composition can be 5 to 35 mol%.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, the present invention provides a magnetic ferrite layer having a magnetostriction constant of 10%.
A magnetic ferrite sintered body of × 10 ⁻⁶ or less is used. This is based on the finding that the degree of deterioration of ferrite permeability μ having a low magnetostriction constant due to stress is small. As this fact will be shown in the examples described later, here, the cause of the fact that the degree of deterioration of the magnetic permeability μ due to stress decreases as ferrite having a lower magnetostriction constant will be described. The present inventors have developed MgCuZn ferrite and NiCuZn.
The deterioration of magnetic permeability μ due to stress was observed using ferrite. As a result, the MgCuZn ferrite is more NiC
It was confirmed that the degree of deterioration of the magnetic permeability μ was smaller than that of uZn ferrite. By the way, it is known that the initial magnetic permeability (μi) is defined by the following equation. From this equation, it can be said that a material having a smaller magnetostriction constant can suppress the deterioration of the magnetic permeability μ. μi = AMs ² / (aK ₁ + bλ _s σ) (Ms = saturated magnetic flux density, K ₁ = anisotropic constant, λ _s = magnetostriction constant, σ = stress) Comparing the magnetostriction constants of MgCuZn ferrite and NiCuZn ferrite, Mg over ferrite
CuZn ferrite has a lower magnetostriction constant. Although the magnetostriction constant varies depending on the composition, the magnetostriction constant of NiCuZn ferrite exceeds 10 × 10 ^-6 ,
Ferrite shows a value of 10 × 10 ⁻⁶ or less. This is presumed to be the reason that the use of MgCuZn ferrite reduces the degree of deterioration of the magnetic permeability μ due to stress.

Conventionally, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-65807, a magnetic layer and an internal electrode are opposed to each other via a gap in order to alleviate the stress from the internal electrode. As disclosed in Japanese Patent No. 223414, it has been proposed to reduce the stress from the crystal grain boundary by making Bi exist in the crystal grain boundary. That is, the conventional proposal was to reduce the stress term (σ) in the above equation to prevent the magnetic permeability from deteriorating. In contrast, the present invention is intended to prevent the deterioration of magnetic permeability by using a material having a small magnetostriction constant.
It can be said that it is based on an idea different from the conventional one. In addition, MgCuZn ferrite can be manufactured at a lower cost than NiCuZn ferrite, which is a great merit for electronic equipment parts whose cost reduction is further progressing. In the present invention, the magnetostriction constant is 10 ×
If it is 10 ^-6 or less, the problem of the present invention can be basically solved. However, it is desirable to use a magnetic ferrite of 7 × 10 ^-6 or less, more preferably 5 × 10 ^-6 or less.

The magnetostriction constant of MgCuZn ferrite is 10
As described above, the value becomes × 10 ⁻⁶ or less.
Hereinafter, the composition of MgCuZn ferrite suitable for the present invention will be described. The amount of Fe ₂ O ₃ has a great influence on the magnetic permeability. If the content of Fe ₂ O ₃ is less than 40 mol%, the magnetic permeability is small, and the magnetic permeability increases as the stoichiometric composition as ferrite approaches, but sharply decreases with the stoichiometric composition as a peak. Therefore, the upper limit is 51mo
l%. Desirable amount of Fe ₂ O ₃ is 45 to 49.8 m
ol%. CuO is a compound that contributes to a reduction in the firing temperature in the present invention, and if it is less than 5 mol%, low-temperature firing at 940 ° C. or lower cannot be realized. However, if the content exceeds 30 mol%, the specific resistance of ferrite decreases and the quality factor Q deteriorates. Desirable CuO content is 7 to 30 mol%.

As the amount of ZnO increases, the magnetic permeability μ increases.
However, if it is too large, the Curie temperature becomes 100 ° C. or lower, and the temperature characteristics required for electronic components cannot be satisfied. Therefore, the amount of ZnO is set to 0.5 to 35 mol%. Desirable ZnO content is 15
２５25 mol%. MgO has the effect of lowering the magnetostriction constant of the magnetic ferrite. 5 to get this effect
It is necessary that the amount be at least mol%. However, Mg
Since the magnetic permeability μ tends to decrease as the amount of O increases, the content is set to 50 mol% or less. The desired amount of MgO is
It is 5-35 mol%, more preferably 7-26 mol%. In the magnetic ferrite powder and magnetic ferrite of the present invention, a part of MgO can be replaced by NiO, but the amount added at that time is 5 to 50 in total with MgO.
mol%, desirably 7 to 26 mol%. When a part of MgO is replaced with NiO, the amount of NiO is 7 of the total amount.
Desirably, it is 0% or less. If it exceeds 70%, the magnetostriction constant of the magnetic ferrite obtained will be high, and it will be difficult to obtain the effect of preventing the deterioration of the magnetic permeability μ. In addition, MgO
Together with or instead of MgO, Mg (OH) ₂ , Mg
CO ₃ can also be used. The magnetic properties of the magnetic ferrite have a very strong composition dependence, and in a region outside the above composition range, the magnetic permeability μ and the quality factor Q become low, and the magnetic ferrite is not suitable as a laminated ferrite part.

By the way, in order to manufacture the laminated ferrite component of the present invention, it is necessary to perform the co-firing.
This simultaneous firing needs to be performed at a low temperature of 940 ° C. or less in consideration of the melting point of Ag or an Ag alloy serving as an internal electrode. For that purpose, the powder for magnetic ferrite before firing,
It is important that the peak position of the particle size distribution is in the range of 1.2 μm or less. The present inventor has conducted studies on low-temperature firing of MgCuZn ferrite, and found that the peak position of the particle size distribution of the powder before firing was reduced to 1.2 μm or less for MgCuZn ferrite, which was conventionally difficult to fire at low temperature. It has been found that low temperature firing becomes possible.
In addition, it has been found that in order to obtain a powder having such a particle size distribution, it is effective to suppress the calcining temperature to 900 ° C., preferably 850 ° C. or less. It has been clarified that the provision of the above conditions of the calcining temperature and the particle size distribution of the powder enables the MgCuZn ferrite to be fired at a low temperature, that is, at a temperature of 940 ° C. or lower while securing sufficient characteristics.

By setting the calcination temperature to 900 ° C. or lower, low-temperature calcination can be performed. Desirable calcining temperature is 73
0-850 ° C. After calcining, the calcined body is crushed,
The ground powder is fired. It is important for the present invention that the particle size distribution of the powder has a peak position in the range of 0.3 to 1.2 μm. That is, if the peak position of the particle size distribution exceeds 1.2 μm, it becomes difficult to fire at a low temperature, more specifically, at a temperature of 940 ° C. or lower. Conversely, when the peak position of the particle size distribution is 1.2 μm or less, 94
Since a shrinkage ratio of 10% or more in firing at a temperature of 0 ° C. or less can be ensured, a magnetic ferrite having sufficient characteristics can be obtained. However, when the thickness is less than 0.3 μm, the specific surface area increases, and it becomes difficult to obtain a paste or sheet for obtaining a laminated ferrite component. A desirable peak position of the particle size distribution is 0.5 to 1.0 μm.
The powder having such a particle size distribution may be obtained by controlling the pulverization conditions, but the powder having such a particle size distribution can also be collected from the pulverized powder without controlling the conditions.

The raw material powder for obtaining the magnetic ferrite according to the present invention is a mixed powder of MgO powder, Fe ₂ O ₃ powder, CuO powder and ZnO powder. Part of MgO is Ni
When substituting with O, NiO powder is also mixed. Also, Mg (O) is used together with or instead of MgO.
H) ₂ , when MgCO ₃ is used, Mg (OH) ₂ ,
MgCO ₃ may be mixed. In order to accelerate the low-temperature firing of the present invention, various glasses such as borosilicate glass and low-melting oxides such as V ₂ O ₅ , Bi ₂ O ₃ , B ₂ O ₃ , WO ₃ and PbO are added. You can also.

Next, a multilayer chip inductor, which is an embodiment of a multilayer ferrite component, will be described. FIG. 1 is a schematic sectional view of a multilayer chip inductor, and FIG.
It is II sectional drawing. As shown in FIG. 1, a multilayer chip inductor 1 has a multilayered chip body 4 in which a magnetic ferrite layer 2 and internal electrodes 3 are alternately stacked, and the internal electrodes 3 are electrically connected to both ends of the chip body 4. And external electrodes 5 arranged to be electrically conductive. The magnetic ferrite material according to the present invention is used for the magnetic ferrite layer 2. That is, a powder having a peak position of 0.3 to 1.2 μm in the particle size distribution is kneaded with a binder and a solvent to obtain a paste for forming the magnetic ferrite layer 2. The paste and the paste for forming the internal electrodes 3 are alternately printed and laminated, and then fired to obtain an integrated chip body 4. As the binder, a known binder such as ethyl cellulose, an acrylic resin, or a butyral resin can be used. In addition, a known solvent such as terpionel, butyl carbitol, and kerosene can be used as the solvent. There are no restrictions on the amounts of binder and solvent added. However, it is recommended that the content be in the range of 1 to 5 parts by weight for the binder and 10 to 50 parts by weight for the solvent. In addition to the binder and the solvent, a dispersant, a plasticizer, a dielectric, an insulator and the like can be added in a range of 10 parts by weight or less. Sorbitan fatty acid esters and glycerin fatty acid esters can be added as dispersants. Further, as a plasticizer, dioctyl phthalate, dibutyl phthalate, and butyl butyl phthalyl glycolate can be added.

The magnetic ferrite layer 2 can be formed using a sheet for the magnetic ferrite layer 2. That is,
A powder having a peak position of the particle size distribution of 0.3 to 1.2 μm, a binder containing polyvinyl butyral as a main component,
A slurry is obtained by kneading with a solvent such as toluene or xylene in a ball mill. The slurry is applied onto a film such as a polyester film by, for example, a doctor blade method and dried to obtain a sheet for the magnetic ferrite layer 2. If the sheet for the magnetic ferrite layer 2 is alternately laminated with the paste for the internal electrode 3 and then fired, the chip body 4 having a multilayer structure can be obtained. Although the amount of the binder is not limited, it is recommended that the amount be in the range of 1 to 5 parts by weight. Further, a dispersant, a plasticizer, a dielectric, an insulator, and the like can be added in a range of 10 parts by weight or less.

The internal electrode 3 is made of Ag or Ag having a small resistivity in order to obtain a practical quality factor Q as an inductor.
It is desirable to use an alloy, for example, an Ag-Pd alloy.
However, the present invention is not limited to this, and Cu, Pd, or an alloy thereof can also be used. The paste for obtaining the internal electrode 3 is obtained by mixing a powder of Ag or an Ag alloy or an oxide powder thereof, a binder and a solvent,
It can be obtained by kneading. As the binder and the solvent, those similar to those used for the paste for forming the magnetic ferrite layer 2 can be applied. As shown in FIG. 3, each layer of the internal electrode 3 has an elliptical shape, and each layer of the adjacent internal electrode 3 has a spiral shape as shown in FIG. Is configured. As a material of the external electrode 5, a known material such as Ag, Ni, Cu, or an Ag-Pd alloy can be used. The external electrode 5 can be formed from these materials by various methods such as a printing method, a plating method, an evaporation method, an ion plating method, and a sputtering method.

The outer diameter and dimensions of the chip body 4 of the multilayer chip inductor 1 are not particularly limited. It can be set appropriately according to the application. Generally, the outer shape is almost a rectangular parallelepiped, and the dimensions are 1.0 to 4.5 mm × 0.5 to
Many have a range of 3.2 mm x 0.6 to 1.9 mm.
The thickness t1 between the electrodes of the magnetic ferrite layer 2 and the thickness t2 of the base are not particularly limited, and the thickness t1 between the electrodes is 10 to 100 μm, and the thickness t2 of the base is 250 to 100 μm.
It can be set at about 500 μm. Further, the thickness t3 of the internal electrode 3 itself can be usually set in the range of 5 to 30 μm, and the pitch of the winding pattern is 10 to 100 μm.
The number of turns can be about 1.5 to 20.5 turns.

The firing temperature after alternately laminating the paste or sheet for the magnetic ferrite layer 2 and the paste for the internal electrode 3 is 940 ° C. or less. If the temperature exceeds 940 ° C., the material constituting the internal electrode 3 diffuses into the magnetic ferrite layer 2 and the magnetic properties may be significantly reduced. Although the magnetic ferrite of the present invention is suitable for low-temperature firing, firing at a temperature lower than 800 ° C is insufficient. Therefore, it is desirable that the firing be performed at 800 ° C. or higher. Desirable firing temperature is 820-930 ° C, more preferably 875-920 ° C. The firing time may be set in 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 laminated type LC composite component will be described. FIG. 3 is a schematic sectional view of the LC composite component. As shown in FIG. 3, the LC composite component 11 is one in which a chip capacitor section 12 and a chip ferrite section 13 are integrated. The chip capacitor section 12 has a multilayer laminated structure in which ceramic dielectric layers 21 and internal electrodes 22 are alternately laminated and integrated. 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 having a low firing temperature is desirable,
A titanate-based composite oxide, a zirconate-based composite oxide, or a mixture thereof can be used. In order to further lower the firing temperature, various glasses such as borosilicate glass may be added. As the internal electrode 22, the same material as that of the internal electrode 2 of the multilayer chip inductor 1 described above can be used. Each internal electrode 22 is alternately electrically connected to another external electrode 15.

The chip ferrite section 13 is composed of a multilayer chip inductor 1 in which magnetic ferrite layers 32 and electrode layers 33 are alternately stacked. This configuration is the same as that of the multilayer chip inductor 1 described above. Therefore, the detailed description here is omitted. LC composite parts 11
There is no limitation on the outer diameter and dimensions of the multilayer chip inductor 1 described above. Therefore, it can be set appropriately according to the application. Usually, it has a substantially rectangular parallelepiped outer shape, 1.6 to 10.0 mm x 0.8 to 15.0 m
It has a size of about mx 1.0 to 5.0 mm.

[0021]

The present invention will be described below with reference to specific examples. Example 1 A magnetic ferrite material was manufactured according to the composition shown in Table 1 and the manufacturing conditions described below. The particle size distribution of the powder before firing, and the magnetic permeability μ, anti-stress characteristics, magnetostriction constant, and density of the obtained magnetic ferrite were measured under the following conditions. Table 2 shows the results of the magnetic permeability μ, the magnetostriction constant, and the density, and FIGS. 4 and 5 show the anti-stress characteristics. <Manufacturing conditions> The raw material powders weighed according to Table 1 were wet-mixed (pure water was used as a dispersion medium) for 16 hours using a ball mill made of a stainless steel pot and a steel ball medium.
After the mixing, the mixed powder was dried by a spray dryer. After drying, calcination was performed at 760 ° C. for 10 hours. After the completion of the calcining, the calcined body was pulverized by the ball mill for 66 hours, and the pulverized powder was calcined to obtain a toroidal calcined body and a rectangular parallelepiped calcined body. Firing temperature is 900
° C and the holding time is 2 hours.

The measuring method of each characteristic is as follows. <Magnetostriction constant> The measurement was performed using a 5 × 5 × 20 mm sample using a saturation magnetostriction measuring device manufactured by Naruse Scientific Instruments. <Particle size distribution> 0.02 g of the powder for which the particle size
Disperse in 0 cc of water. After the measurement path of the particle size distribution meter was washed and the reference of the particle size distribution meter was measured, the particle size distribution of the powder was measured. For measurement of powder dispersion and particle size distribution, SYMPATEC's HEROS
The system was used. The particle size distribution and frequency were calculated using a laser diffraction method by a program of a particle size distribution meter. <Permeability> A toroidal sample is wound around a copper wire (wire diameter 0.35 mm) for 20 turns, and the measurement frequency is 100K.
The inductance was measured using an LCR meter (manufactured by Hewlett-Packard Co., Ltd.) at a measurement current of 0.2 mA at Hz, and the magnetic permeability was determined using the following equation. Magnetic permeability μ = (le × L) / (μ ₀ × Ae × N ² ) le: magnetic path length L: inductance of sample μ ₀ : magnetic permeability of vacuum = 4π × 10 ⁻⁷ (H / m) Ae:
Cross section area of sample N: Number of turns of coil <Stress resistance> A copper wire (0.35 mm in diameter) is wound around a square toroidal sample for 20 turns and connected to an LCR meter (Hewlett-Packard Co., Ltd.). The measurement frequency is 10
The rate of decrease in inductance was measured under the conditions of 0 kHz and a measurement current of 0.2 mA. Since the reduction rate of the inductance is proportional to the reduction rate of the magnetic permeability μ, it is shown in FIGS. 4 and 5 as the reduction rate of the magnetic permeability μ.

[0023]

[Table 1]

[0024]

[Table 2]

Tables 1 and 2 reveal the following. First, no. 3 and No. No. 1 is No. 1 3 to 14 MgO
mol%, No. 1 differs in that 14 mol% of NiO is added, but the other compositions are the same. Both magnetostriction constants (λ
_s ), no. 3 is 3 × 10 ⁻⁶ , No. 3 1 is 1
It is 2 × 10 ⁻⁶ . That is, it is understood that the MgCuZn ferrite has a significantly lower magnetostriction constant than the NiCuZn ferrite. This is because No. 2 having the same composition except for MgO and NiO. 4 and No. It can also be understood from the magnetostriction constant of 2. In addition, No. 1 and No. 2 and N
The magnetostriction constant greatly fluctuates from 12 × 10 ^-6 to 18 × 10 ^{-6 as the} iO amount increases from 14 mol% to 21 mol%. On the other hand, No. 3 and No. In comparison with No. 4, even if MgO increases from 14 mol% to 21 mol%, the magnetostriction constant only changes from 3 × 10 ^-6 to 3.2 × 10 ^-6 . In other words, it is understood that even if the amount of MgO increases, the magnetostriction constant does not basically increase. No. 5 is M
In this example, NiO was added together with gO. Compared to 1 and 2, the magnetostriction constant is low and the magnetic permeability μ is also a good value.

FIG. 3 and No. 3 Permeability μ of 1
5 shows the anti-stress characteristics of FIG. 4 and no. 2 shows the anti-stress characteristic with a magnetic permeability μ of 2. From FIGS. 4 and 5,
It can be understood that the magnetic permeability μ is deteriorated by applying the stress.
However, from FIG. 3 (3 × 1
0 ^-6) is the magnetostriction constant greater No. It can be seen that the degree of deterioration of the magnetic permeability μ is smaller than 1 (12 × 10 ⁻⁶ ).
The same can be said from FIG. Therefore, in order to reduce the degree of deterioration of the magnetic permeability μ due to stress, it is effective to use MgCuZn-based ferrite having a small magnetostriction constant.

Next, 2.5 parts by weight of ethyl cellulose and 40 parts by weight of terpineol were added to 100 parts by weight of each powder having the composition shown in Table 1, and the mixture was kneaded with a three-roll mill to obtain a paste for the magnetic ferrite layer 2. It was adjusted. On the other hand, 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 diameter of 0.8 μm, and the mixture was kneaded with a three-roll mill to prepare a paste for internal electrodes. After alternately printing and laminating the paste for the magnetic ferrite layer 2 and the paste for the internal electrode,
By firing for a time, the multilayer chip inductor 1 shown in FIGS. 1 and 2 was obtained. The dimensions of the 2012 type multilayer chip inductor 1 are 2.0 mm × 1.2 mm × 1.
1 mm, and the number of turns of the coil was 4.5 turns. Next, an external electrode made of Ag was formed at the end of the multilayer chip inductor 1 by baking at 600 ° C. The obtained laminated chip inductor 1 was measured at a measurement frequency of 100 kHz.
z, the inductance L and the quality factor Q were measured using an LCR meter (manufactured by Hewlett-Packard Co.) at a measurement current of 0.2 mA. Table 2 shows the results. MgCuZ
Even when n ferrite and MgNiCuZn ferrite were used, characteristics equivalent to those of the multilayer chip inductor 1 using conventional NiCuZn ferrite could be obtained.

Example 2 Example 2 was performed to confirm the effect of the CuO content. Using the composition shown in Table 3, a sample was prepared under the same manufacturing conditions as in Example 1, and the magnetic permeability μ and the density were measured. The measurement conditions of the magnetic permeability μ are the same as those in the first embodiment. Table 4 shows the results.

[0029]

[Table 3]

[0030]

[Table 4]

From Tables 3 and 4, it can be seen that the magnetic permeability μ increases with an increase in the amount of CuO, but decreases greatly when it exceeds 24 mol%. Moreover, the amount of CuO is 4.0mo.
At 1%, practically sufficient magnetic properties cannot be obtained, and 28.0 mol
%, The magnetic properties also deteriorate. Therefore, from the viewpoint of magnetic properties, the amount of CuO is 5 mol% or more and 25 mol%.
It is desirable to do the following. No. 3 in Table 3. 6 (CuO content:
4.0 mol%), No. 7 (CuO content: 8.0 mol%),
No. No. 8 (CuO content: 12.0 mol%); 9 (C
uO amount: 16.0 mol%). 11 (CuO content: 2
(4.0 mol%) and the shrinkage ratio (ΔL / L) when heated to a predetermined temperature using the calcined powder was measured. This shrinkage ratio is a measure of the ease of firing, and the higher the shrinkage ratio, the easier the firing. FIG. 6 shows the results. The diagram in FIG. 6 is called a heat shrinkage curve. FIG. 6 shows that the shrinkage ratio increases as the CuO amount increases. That is, it is shown that the addition of CuO facilitates the firing, and enables firing at a lower temperature. No. 9 (CuO content: 16.0 mol%) and N
o. 11 (CuO content: 24.0 mol%)
The shrinkage at each temperature is almost equal. Therefore, from the viewpoint of easiness of firing, it is understood that the addition of CuO in an amount of about 20.0 mol% is sufficient. On the other hand, No. 6 (CuO
Amount: 4.0 mol%) 7 (CuO content: 8.0 mol)
%), The CuO content should be 7 mol%, more desirably 10.0 mol% or more, in order to sufficiently enable low-temperature sintering.

Further, a multilayer chip inductor was prepared in the same manner as in the first embodiment, and the inductance L and the quality factor Q were measured in the same manner as in the first embodiment. Table 4 shows the results. Even in the multilayer chip inductor, the CuO amount is 8.0 to 2
It was confirmed that good inductance L and quality factor Q were obtained in the example of 4.0 mol%.

Example 3 Example 3 was performed for the purpose of confirming the influence of the calcining temperature. Samples were prepared under the same manufacturing conditions (sintering temperature: 900 ° C.) as in Example 1 except that calcination was performed at various temperatures with the composition shown in Table 5, and the magnetic permeability μ and density were determined in the same manner as in Example 1. Was measured. Table 6 shows the measurement results of the peak position, the magnetic permeability μ, and the density of the particle size distribution at each calcination temperature.

[0034]

[Table 5]

[0035]

[Table 6]

The general tendency is that the calcining temperature is 85
Up to the range of 0 ° C., as the calcining temperature increases, the magnetic permeability μ and the density increase. This means that the effect of the calcination is exhibited together with the improvement of the calcination temperature. Also,
When the calcination temperature is as high as 900 ° C., the magnetic permeability μ and the density decrease. After calcining the raw material powders having the composition shown in Table 5 at 850 ° C., two kinds of powders shown in FIG. 7 were obtained by changing the pulverization conditions. Using these two types of powders, a heat shrinkage curve was obtained in order to observe the influence of the peak position of the particle size distribution on the firing. FIG. 8 shows the result. The peak position of the particle size distribution is 750 to 750 which was measured for the powder of 0.62 μm as compared with the powder of 1.38 μm.
It can be seen that the shrinkage is large in the range of 1000 ° C. It can be said that the higher the shrinkage ratio, the easier the baking proceeds, so that the peak position of the particle size distribution is 0.6
It can be seen that 2 μm powder is more excellent in sinterability. As described above, in the present invention, firing at a low temperature of 940 ° C. or less is required to enable simultaneous firing with Ag or an Ag alloy forming an internal electrode.
On the other hand, a powder having a particle size distribution having a peak position of 0.62 μm has a larger shrinkage ratio in the range of 940 ° C. or lower than a powder having a particle diameter of 1.38 μm, and is therefore suitable for low-temperature firing.

In Table 6, No. 15 (calcination temperature: 7
No. 60 ° C.). No. 18 (calcination temperature: 850 ° C.) The shrinkage when heating to a predetermined temperature using the ground powder after calcination of 19 (calcination temperature: 900 ° C.) was measured. FIG. 9 shows the results. 850 among 3 calcining temperatures
C. No. 18 shows the largest shrinkage ratio and is suitable for low-temperature firing. When the calcining temperature was 900 ° C. 1
In No. 9, since the calcined body was too hard and pulverization was not sufficiently performed, the shrinkage ratio was No. 9. It is presumed that it became smaller than 18. In addition, in the case of the calcination temperature of 760 ° C.
In No. 15, since the single-phase structure of spinel was not obtained by calcination, the shrinkage ratio due to heating was No. 15. It is estimated that the result was inferior to 18. According to a study conducted separately, it has been confirmed that a single-phase structure of spinel can be obtained by performing calcination at a temperature of 800 ° C. or higher. Therefore, it is also important to set the calcining temperature in consideration of this point.

Next, a multilayer chip inductor was prepared in the same manner as in Example 1, and the inductance L and the quality factor Q were measured in the same manner as in Example 1. Table 6 shows the results. When the calcining temperature is 850 ° C. or lower, good inductance L and quality factor Q can be obtained, but when the temperature reaches 900 ° C., inductance L and quality factor Q sharply decrease.

Example 4 Example 4 was performed to confirm the effect of the firing temperature. A sample was prepared under the same manufacturing conditions as in Example 1 (calcining temperature: 760 ° C.) except that firing was performed at various temperatures with the composition shown in Table 7, and the magnetic permeability μ and the density were determined in the same manner as in Example 1. Was measured.
Table 8 shows the measurement results of the magnetic permeability μ and the density at each firing temperature. Further, a multilayer chip inductor was prepared in the same manner as in Example 1, and the inductance L and the quality factor Q were measured in the same manner as in Example 1. The results are also shown in Table 8.

[0040]

[Table 7]

[0041]

[Table 8]

In Table 8, the magnetic permeability μ and density of the fired body increase as the firing temperature increases. Therefore, it can be said that it is desirable to select a high firing temperature only from this result. However, the inductance L and the quality factor Q of the multilayer chip inductor decrease sharply at the firing temperature of 950 ° C. This is because Ag constituting the internal electrode diffused into the magnetic ferrite layer. Therefore, when manufacturing a laminated ferrite component using Ag or an Ag alloy as an internal electrode, 95%
It is necessary to fire at a temperature below 0 ° C.

[0043]

As described above, according to the present invention,
Low deterioration of magnetic permeability μ due to stress and low temperature firing,
That is, a laminated ferrite component that can be fired at a temperature equal to or lower than the melting point of Ag or an Ag alloy used as an electrode material can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a multilayer chip inductor according to the present embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view of the LC composite component according to the present embodiment.

FIG. 4 MgCuZn ferrite and NiCuZn
4 is a graph showing the anti-stress characteristic of the magnetic permeability μ of ferrite.

FIG. 5: MgCuZn ferrite and NiCuZn
4 is a graph showing the anti-stress characteristic of the magnetic permeability μ of ferrite.

FIG. 6 is a graph showing a heat shrinkage curve when the amount of CuO is changed.

FIG. 7 is a graph showing a particle size distribution measured in Example 3.

FIG. 8 is a graph showing a heat shrinkage curve when the peak position of the particle size distribution is changed.

FIG. 9 is a graph showing a heat shrinkage curve when the calcination temperature is changed.

[Explanation of symbols]

1. Multilayer chip inductor 2. Magnetic ferrite layer
3 ... internal electrode, 4 ... chip body, 5 ... external electrode, 11 ... L
C composite parts, 12: chip capacitor part, 13: chip ferrite part, 15: external electrode, 21: ceramic dielectric layer, 22: internal electrode, 32: magnetic ferrite layer, 3
3 ... Electrode layer

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 23, 2000 (2000.6.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art Laminated chip ferrite parts and composite laminated ferrite parts (collectively referred to as laminated ferrite parts in this specification) are used in various electric devices because of their small volume and high reliability. Have been. This laminated ferrite component is usually formed by laminating and integrating 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. It is manufactured by printing or transferring an electrode paste and then baking. Note that firing after lamination and integration is called simultaneous firing. Since Ag or Ag alloy is used as the material for the internal electrode because of its low resistivity, the magnetic ferrite material constituting the magnetic layer can be co-fired, in other words, it has a melting point lower than the melting point of Ag or Ag alloy. An absolute condition is that firing can be performed at a temperature. Therefore, in order to obtain a high-density, high-characteristic laminated ferrite component, the key is whether the magnetic ferrite can be fired at a temperature equal to or lower than the melting point of Ag or an Ag alloy.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

[0003] NiCuZn ferrite is known as a magnetic ferrite that can be fired at a temperature lower than the melting point of Ag or an Ag alloy. That is, the specific surface area is reduced to 6 by pulverization.
NiCuZn using raw material powder of about m ² / g or more
Since ferrite can be fired at a temperature equal to or lower than the melting point of Ag (960 ° C.), it is widely used for laminated ferrite parts. However, NiCuZn ferrite has a magnetic property, particularly a magnetic permeability μ, which is sensitive to external stress and thermal shock (for example, see “Powder and Powder Metallurgy” vol. 39,8, 612).
-617 (1992)), the following problems occur in the production of laminated ferrite parts. In other words, the stress caused by the barrel polishing and plating operations performed during the manufacturing process, the stress resulting from the difference in the linear expansion coefficient between the magnetic layer and the internal electrode, and the stress generated during mounting on a printed circuit board cause the magnetic permeability μ.
Is deteriorated, and the inductance L deviates from a design value. To solve this problem, the present inventors have already made two proposals. One is that the magnetic layer and the internal electrode are opposed to each other via a gap (Japanese Patent Application Laid-Open No. 4-65807). This proposal aims to avoid the stress caused by the difference in linear expansion coefficient between the magnetic layer and the internal electrode. The other is NiCuZn
By making Bi exist at the grain boundaries of ferrite,
After firing causing tensile stress in the crystal grains, it is that attempts to desensitize the sensitivity of the magnetic characteristic of the external stress (JP-A-10-2234 2 4 No.). The above two proposals are effective methods for reducing the magnetic properties of NiCuZn ferrite due to stress.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, the present invention provides a magnetic ferrite layer having a magnetostriction constant of 10%.
A magnetic ferrite sintered body of × 10 ⁻⁶ or less is used. This is due to the fact that the knowledge that there is a small degree of deterioration due to the stress of the ferrite magnetic permeability μ magnetostrictive constant number is not small. As it indicated in the examples this fact to be described later, where it is noted the cause of degree less deterioration due to the stress of the permeability μ as ferrite magnetostriction constants is less. The present inventor has proposed that MgCuZn ferrite and NiC
The deterioration of the magnetic permeability μ due to stress was observed using uZn ferrite. As a result, it was confirmed that the degree of deterioration of the magnetic permeability μ of the MgCuZn ferrite was smaller than that of the NiCuZn ferrite. By the way, initial permeability (μi)
Is known to be defined by the following equation: From this equation, it can be said that it is possible to suppress the deterioration of the permeability μ as magnetostriction constants are small materials. _{^{μi = AMs 2 / (aK 1}} + bλ S σ) (Ms = saturation flux density, K ₁ = anisotropy constant, lambda _S = magnetostriction constant, sigma = stress) Comparing the magnetostrictive constants of MgCuZn ferrite and NiCuZn ferrite, Mg from NiCuZn ferrite
Those of CuZn ferrite the number of magnetostrictive constant is less. Although varying the magnetostriction constants composition, Mg whereas magnetostriction constants of NiCuZn ferrite will exceed the 10 × 10 ^-6 NiC
uZn ferrite shows a value of 10 × 10 ⁻⁶ or less. This is presumed to be the reason that the use of MgCuZn ferrite reduces the degree of deterioration of the magnetic permeability μ due to stress.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

Conventionally, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-65807, a magnetic layer and an internal electrode are opposed to each other via a gap in order to alleviate the stress from the internal electrode. As disclosed in Japanese Patent No. 223414, it has been proposed to reduce the stress from the crystal grain boundary by making Bi exist in the crystal grain boundary. That is, the conventional proposal was to reduce the stress term (σ) in the above equation to prevent the magnetic permeability from deteriorating. In contrast, the present invention is intended to prevent the deterioration of magnetic permeability by using a material having a small magnetostriction constant.
It can be said that it is based on an idea different from the conventional one. In addition, MgCuZn ferrite can be manufactured at a lower cost than NiCuZn ferrite, which is a great merit for electronic equipment parts whose cost reduction is further progressing. In the present invention, the magnetostriction constants are 10 ×
If it is 10 ^-6 or less, the problem of the present invention can be basically solved. However, it is desirable to use a magnetic ferrite of 7 × 10 ^-6 or less, more preferably 5 × 10 ^-6 or less.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009] The magnetostrictive constant number of MgCuZn ferrite 10
As described above, the value becomes × 10 ⁻⁶ or less.
Hereinafter, the composition of MgCuZn ferrite suitable for the present invention will be described. The amount of Fe ₂ O ₃ has a great influence on the magnetic permeability. If the content of Fe ₂ O ₃ is less than 40 mol%, the magnetic permeability is small, and the magnetic permeability increases as the stoichiometric composition as ferrite approaches, but sharply decreases with the stoichiometric composition as a peak. Therefore, the upper limit is 51mo
l%. Desirable amount of Fe ₂ O ₃ is 45 to 49.8 m
ol%. CuO is a compound that contributes to a reduction in the firing temperature in the present invention, and if it is less than 5 mol%, low-temperature firing at 940 ° C. or lower cannot be realized. However, 30mol%
And 5~30mol% since the deterioration of the quality factor Q resistivity of the ultra-El and the ferrite is reduced. Desirable CuO content is 7 to 30 mol%.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

As the amount of ZnO increases, the magnetic permeability μ increases.
However, if it is too large, the Curie temperature becomes 100 ° C. or lower, and the temperature characteristics required for electronic components cannot be satisfied. Therefore, the amount of ZnO is set to 0.5 to 35 mol%. Desirable ZnO content is 15
２５25 mol%. MgO has the effect of lowering the magnetostriction constant of the magnetic ferrite. 5 to get this effect
It is necessary that the amount be at least mol%. However, Mg
Since the magnetic permeability μ tends to decrease as the amount of O increases, the content is set to 50 mol% or less. The desired amount of MgO is
It is 5-35 mol%, more preferably 7-26 mol%. In the magnetic ferrite powder and magnetic ferrite of the present invention, a part of MgO can be replaced by NiO, but the amount added at that time is 5 to 50 in total with MgO.
mol%, desirably 7 to 26 mol%. When a part of MgO is replaced with NiO, the amount of NiO is 7 of the total amount.
Desirably, it is 0% or less. 70% magnetostriction constant of the magnetic ferrite obtained ultra obtain size no longer permeability μ
This is because it becomes difficult to obtain the effect of preventing the deterioration of the metal. In addition, Mg
Mg (OH) ₂ , M with O or in place of MgO
gCO ₃ can also be used. Magnetic properties of the magnetic ferrite composition dependency is very strong, in the region outside the above composition range, the permeability μ and the quality factor Q is small no longer, is not suitable as a multilayer ferrite components.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

By setting the calcination temperature to 900 ° C. or lower, low-temperature calcination can be performed. Desirable calcining temperature is 73
0-850 ° C. After calcining, the calcined body is crushed,
The ground powder is fired. It is important for the present invention that the particle size distribution of the powder has a peak position in the range of 0.3 to 1.2 μm. That is, the particle size distribution is exceeded and low-temperature firing peak position of 1.2μm of, it becomes difficult to fire at 940 ° C. temperature below more specifically. Conversely, when the peak position of the particle size distribution is 1.2 μm or less, 94
Since a shrinkage ratio of 10% or more in firing at a temperature of 0 ° C. or less can be ensured, a magnetic ferrite having sufficient characteristics can be obtained. However, when the thickness is less than 0.3 μm, the specific surface area increases, and it becomes difficult to obtain a paste or sheet for obtaining a laminated ferrite component. A desirable peak position of the particle size distribution is 0.5 to 1.0 μm.
The powder having such a particle size distribution may be obtained by controlling the pulverization conditions, but the powder having such a particle size distribution can also be collected from the pulverized powder without controlling the conditions.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Next, a multilayer chip inductor, which is an embodiment of a multilayer ferrite component, will be described. FIG. 1 is a schematic sectional view of a multilayer chip inductor, and FIG.
It is II sectional drawing. As shown in FIG. 1, a multilayer chip inductor 1 has a multilayered chip body 4 in which a magnetic ferrite layer 2 and internal electrodes 3 are alternately stacked, and the internal electrodes 3 are electrically connected to both ends of the chip body 4. And external electrodes 5 arranged to be electrically conductive. The magnetic ferrite material according to the present invention is used for the magnetic ferrite layer 2. That is, a powder having a peak position of 0.3 to 1.2 μm in the particle size distribution is kneaded with a binder and a solvent to obtain a paste for forming the magnetic ferrite layer 2. The paste and the paste for forming the internal electrodes 3 are alternately printed and laminated, and then fired to obtain an integrated chip body 4. As the binder, a known binder such as ethyl cellulose, an acrylic resin, or a butyral resin can be used. Further, solvents can also be used Terupi neo Lumpur, butyl carbitol, a known solvent kerosene. There are no restrictions on the amounts of binder and solvent added. However, it is recommended that the binder be in the range of 1 to 5 parts by mass and the solvent 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, an insulator and the like can be added in a range of 10 parts by mass or less. Sorbitan fatty acid esters and glycerin fatty acid esters can be added as dispersants. Further, as a plasticizer, dioctyl phthalate, dibutyl phthalate, and butyl butyl phthalyl glycolate can be added.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

The magnetic ferrite layer 2 can be formed using a sheet for the magnetic ferrite layer 2. That is,
A powder having a peak position of the particle size distribution of 0.3 to 1.2 μm, a binder containing polyvinyl butyral as a main component,
A slurry is obtained by kneading with a solvent such as toluene or xylene in a ball mill. The slurry is applied onto a film such as a polyester film by, for example, a doctor blade method and dried to obtain a sheet for the magnetic ferrite layer 2. If the sheet for the magnetic ferrite layer 2 is alternately laminated with the paste for the internal electrode 3 and then fired, the chip body 4 having a multilayer structure can be obtained. Although the amount of the binder is not limited, it is recommended that the amount be in the range of 1 to 5 parts by mass . Further, a dispersant, a plasticizer, a dielectric, an insulator and the like can be added in a range of 10 parts by mass or less.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

The firing temperature after alternately laminating the paste or sheet for the magnetic ferrite layer 2 and the paste for the internal electrode 3 is 940 ° C. or less. Exceeding 940 ° C., to diffuse the material constituting the internal electrode 3 in the magnetic ferrite layers 2, there is a risk that significantly reduces the magnetic properties. Although the magnetic ferrite of the present invention is suitable for low-temperature firing, firing at a temperature lower than 800 ° C is insufficient. Therefore, it is desirable that the firing be performed at 800 ° C. or higher. Desirable firing temperature is 820-930 ° C, more preferably 875-920 ° C. The firing time may be set in the range of 0.05 to 5 hours, preferably 0.1 to 3 hours.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

The measuring method of each characteristic is as follows. <Magnetostriction constant> The measurement was performed using a 5 × 5 × 20 mm sample using a saturation magnetostriction measuring device manufactured by Naruse Scientific Instruments. <Particle size distribution> 0.02 g of the powder for which the particle size
Disperse in 0 ml of water. After the measurement path of the particle size distribution meter was washed and the reference of the particle size distribution meter was measured, the particle size distribution of the powder was measured. For measurement of powder dispersion and particle size distribution, SYMPATEC's HEROS
The system was used. The particle size distribution and frequency were calculated using a laser diffraction method by a program of a particle size distribution meter. <Permeability> Twenty turns of a copper wire (0.35 mm in diameter) are wound around a toroidal sample, and the measurement frequency is 100 k.
The inductance was measured using an LCR meter (manufactured by Hewlett-Packard Co., Ltd.) at a measurement current of 0.2 mA at Hz, and the magnetic permeability was determined using the following equation. Magnetic permeability μ = (le × L) / (μ ₀ × Ae × N ² ) le: magnetic path length L: inductance of sample μ ₀ : magnetic permeability of vacuum = 4π × 10 ⁻⁷ (H / m) Ae:
Cross section area of sample N: Number of turns of coil <Stress resistance> A copper wire (0.35 mm in diameter) is wound around a square toroidal sample for 20 turns and connected to an LCR meter (Hewlett-Packard Co., Ltd.). The measurement frequency is 10
The rate of decrease in inductance was measured under the conditions of 0 kHz and a measurement current of 0.2 mA. Since the reduction rate of the inductance is proportional to the reduction rate of the magnetic permeability μ, it is shown in FIGS. 4 and 5 as the reduction rate of the magnetic permeability μ.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

Tables 1 and 2 reveal the following. First, no. 3 and No. No. 1 is No. 1 3 to 14 MgO
mol%, No. 1 differs in that 14 mol% of NiO is added, but the other compositions are the same. Both magnetostriction constants (λ
_s ), no. 3 is 3 × 10 ⁻⁶ , No. 3 1 is 1
It is 2 × 10 ⁻⁶ . That is, it is understood that the MgCuZn ferrite has a significantly smaller magnetostriction constant than the NiCuZn ferrite. This is because No. 2 having the same composition except for MgO and NiO. 4 and No. It can also be understood from the magnetostriction constant of 2. In addition, No. 1 and No. Compared to 2,
As the NiO content increases from 14 mol% to 21 mol%, the magnetostriction constant greatly fluctuates from 12 × 10 ^-6 to 18 × 10 ^-6 . On the other hand, No. 3 and No. In comparison with No. 4, even if MgO increases from 14 mol% to 21 mol%, the magnetostriction constant only changes from 3 × 10 ^-6 to 3.2 × 10 ^-6 . That, is understood MgO never size Kusuru magnetostriction constant also basically increases the amount. No. No. 5 is an example in which NiO was added together with MgO. 1
And compared to 2 magnetostriction constant rather small, and also the permeability μ is obtained good values.

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

Next, the powder 100 quality having the composition shown in Table 1
Relative to the amount unit, ethylcellulose 2.5 parts by weight, terpineol 40 parts by weight was added, to adjust the magnetic ferrite layers 2 paste were kneaded by three rolls. On the other hand, 2.5 parts by mass of ethyl cellulose and 40 parts by mass of terpineol were added to 100 parts by mass of Ag having an average particle diameter of 0.8 μm, and the mixture was kneaded with a three-roll mill to prepare a paste for internal electrodes. After alternately printing and laminating the paste for the magnetic ferrite layer 2 and the paste for the internal electrode,
By firing for a time, the multilayer chip inductor 1 shown in FIGS. 1 and 2 was obtained. The dimensions of the 2012 type multilayer chip inductor 1 are 2.0 mm × 1.2 mm × 1.
1 mm, and the number of turns of the coil was 4.5 turns. Next, an external electrode made of Ag was formed at the end of the multilayer chip inductor 1 by baking at 600 ° C. The obtained laminated chip inductor 1 was measured at a measurement frequency of 100 kHz.
z, the inductance L and the quality factor Q were measured using an LCR meter (manufactured by Hewlett-Packard Co.) at a measurement current of 0.2 mA. Table 2 shows the results. MgCuZ
Even when n ferrite and MgNiCuZn ferrite were used, characteristics equivalent to those of the multilayer chip inductor 1 using conventional NiCuZn ferrite could be obtained.

[Procedure amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

[0031] From Table 3 and Table 4, is improved permeability μ as CuO content increases, it can be seen that the greatly reduced Exceeding 24 mol%. Moreover, the amount of CuO is 4.0mo.
At 1%, practically sufficient magnetic properties cannot be obtained, and 28.0 mol
%, The magnetic properties also deteriorate. Therefore, from the viewpoint of magnetic properties, the amount of CuO is 5 mol% or more and 25 mol%.
It is desirable to do the following. No. 3 in Table 3. 6 (CuO content:
4.0 mol%), No. 7 (CuO content: 8.0 mol%),
No. No. 8 (CuO content: 12.0 mol%); 9 (C
uO amount: 16.0 mol%). 11 (CuO content: 2
(4.0 mol%) and the shrinkage ratio (ΔL / L) when heated to a predetermined temperature using the calcined powder was measured. This shrinkage ratio is a measure of the ease of firing, and the higher the shrinkage ratio, the easier the firing. FIG. 6 shows the results. The diagram in FIG. 6 is called a heat shrinkage curve. FIG. 6 shows that the shrinkage ratio increases as the CuO amount increases. That is, it is shown that the addition of CuO facilitates the firing, and enables firing at a lower temperature. No. 9 (CuO content: 16.0 mol%) and N
o. 11 (CuO content: 24.0 mol%)
The shrinkage at each temperature is almost equal. Therefore, from the viewpoint of easiness of firing, it is understood that the addition of CuO in an amount of about 20.0 mol% is sufficient. On the other hand, No. 6 (CuO
Amount: 4.0 mol%) 7 (CuO content: 8.0 mol)
%), The CuO content should be 7 mol%, more desirably 10.0 mol% or more, in order to sufficiently enable low-temperature sintering.

[Procedure amendment 15]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

[Procedure amendment 16]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8

[Procedure amendment 17]

[Document name to be amended] Drawing

[Correction target item name] Fig. 9

[Correction method] Change

[Correction contents]

FIG. 9

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G018 AA07 AA24 AA25 AC05 AC16 AC22 5E041 AB14 AB19 CA01 HB03 NN02 NN15 5E070 AA01 AA05 AB03 AB10 BA12 BB01 CB04 CB08 CB13 CB18 DB08 EA01 EB03

Claims (5)

[Claims] 1. A laminated ferrite component having a magnetic ferrite layer and an internal electrode alternately laminated and having an external electrode electrically connected to the internal electrode, wherein the magnetic ferrite layer has a magnetostriction constant. There is constituted of a magnetic ferrite sintered body of 10 × 10 ^-6 or less, multilayer ferrite parts the internal electrodes, characterized in that they are composed of Ag or an Ag alloy. Wherein said magnetic ferrite sintered body is Fe ₂ O _3:
40 to 51 mol%, CuO: 5 to 30 mol%, ZnO:
The multilayer ferrite component according to claim 1, which is a MgCuZn-based ferrite having a composition of 0.5 to 35 mol% and MgO: 5 to 50 mol%. 3. A multilayer inductor part in which magnetic ferrite layers and internal electrodes are alternately laminated, and a multilayer capacitor part in which dielectric layers and internal electrodes are alternately laminated are integrated with each other. Wherein the magnetic ferrite layer of the multilayer inductor part has a magnetostriction constant of 10 × 10 ⁻⁶ or less. A multilayer ferrite component, comprising: a sintered MgCuZn-based magnetic ferrite body; and wherein the external electrode is made of Ag or an Ag alloy. 4. The fired body of MgCuZn-based magnetic ferrite includes Fe ₂ O ₃ : 45 to 49.8 mol%, CuO: 7 to
30 mol%, ZnO: 15 to 25 mol%, MgO: 5 to
4. The multilayer ferrite component according to claim 3, having a composition of 35 mol%. 5. The fired body of MgCuZn-based magnetic ferrite comprises Fe ₂ O ₃ : 45 to 49.8 mol%, CuO: 7 to 5%.
30 mol%, ZnO: 15 to 25 mol%, MgO + Ni
The multilayer ferrite component according to claim 3, having a composition of O: 5 to 35 mol%.