JP5365967B2 - Polycrystalline ceramic magnetic material, microwave magnetic material, and non-reciprocal circuit device using the same - Google Patents

Description

  The present invention relates to a magnetic material for microwaves used for high-frequency circuit components, and further relates to a polycrystalline ceramic magnetic material that can be simultaneously fired with electrode materials such as silver and copper.

  In recent years, miniaturization of devices has been demanded with the progress of communication technology using electromagnetic waves in the microwave region, such as car phones, mobile phones, and satellite broadcasts. For this purpose, there is an increasing demand for downsizing and low profile of individual parts constituting the equipment.

  As typical high-frequency circuit components used in the field of communication equipment, for example, there are microwave nonreciprocal circuit elements such as circulators and isolators. In general, an isolator has a function such that there is almost no attenuation in the signal transmission direction and the attenuation is increased in the opposite direction. For example, a cellular phone, a car phone, etc. used in the microwave band and the UHF band. This is used in a transmission / reception circuit of a mobile communication device.

  Non-reciprocal circuit elements such as a circulator and an isolator include a central conductor having a plurality of electrode lines arranged in a state of being insulated from each other, a microwave magnetic body disposed in close contact with the central conductor, the central conductor and The central conductor assembly made of the magnetic material for microwaves includes a permanent magnet that applies a DC magnetic field, and the central conductor and the magnetic material for microwaves are manufactured as separate parts. Conventionally, various forms have been proposed, such as winding a copper foil around a microwave magnetic body, or printing and sintering a silver paste on the microwave magnetic body to form an integral body.

In order to meet the demands for downsizing as described above, for example, as described in Patent Document 1, as a material for the central conductor, a conductive paste formed by mixing a conductive powder such as palladium or platinum and an organic solvent is used. It has been proposed that the microwave magnetic material and the central conductor are integrally fired at a temperature of 1300 to 1600 ° C.
JP-A-6-61708

  The above-mentioned palladium or platinum has a high melting point of 1300 ° C. or higher and has an advantage that it can be easily fired integrally with most magnetic materials for microwaves, but has a high specific resistance. For example, when used for an isolator element, There is a disadvantage that the insertion loss is increased.

  In the case of using low resistance silver or copper, in order to obtain a sufficient sintered body in simultaneous firing, it is conceivable to use a polycrystalline ceramic magnetic material substituted with Bi or to add a low melting point glass. However, a microwave magnetic material with a narrow single-phase region is liable to generate a different phase or increase the amount of pores, and thus cannot be a low-loss microwave magnetic material.

  Further, in such a microwave non-reciprocal circuit element, a combination with a permanent magnet is used, but the temperature characteristic of the saturation magnetization 4πMs of the microwave magnetic material compensates for the temperature characteristic of the permanent magnet. It is considered ideal.

Therefore, the present invention solves the above-described problems and can be fired at a low temperature of 850 ° C. or more and 920 ° C. or less , suppresses the generation of heterogeneous even in the Bi substitution type, and reduces the ferromagnetic resonance half width ΔH and dielectric loss. An object is to provide a polycrystalline ceramic magnetic material having a small tan δ and a temperature coefficient αm and a saturation magnetization of 4πMs so as to compensate for the temperature characteristics of a permanent magnet, a microwave magnetic material, and a nonreciprocal circuit device using the same. And

The first invention is a main component of the general formula _{(Y 3.0-x-y Bi} x Ca y) (Fe 5-α-β-γ In α Al β Vγ) have a composition represented by _{O 12} X, y are 0.4 <x ≦ 0.9, 0.5 ≦ y ≦ 1.2, and α, β, γ are 0 ≦ α ≦ 0.4, 0 ≦ β ≦ 0.45,0.25 ≦ γ ≦ 0.6, but be in the range of 0.1 ≦ α + β ≦ 0.75, wherein the Cu及beauty Z r as a sub-component, the content of the With respect to 100 parts by weight of the main component, Cu is CuO ≦ 0.8 wt% in terms of CuO, Zr is Z rO ₂ ≦ 0.8 wt% in terms of ZrO ₂ , and a phase having a garnet structure is the main component. A polycrystalline ceramic magnetic material characterized by sintering at a temperature of 850 ° C. or higher and 920 ° C. or lower .

The polycrystalline ceramic magnetic material according to the present invention has a saturation magnetization 4πMs of 60 mT to 130 mT and a temperature coefficient αm of −0.38% / ° C. to −0.2% / ° C. It is also characterized in that the value width ΔH is 8200 A / m or less.

  A second invention is a microwave magnetic body obtained by integrally sintering the polycrystalline ceramic magnetic material of the first invention and a conductor paste containing either Ag or an Ag alloy, and the microwave magnetism A microwave magnetic body comprising an electrode pattern formed of the conductive paste inside and / or on the surface of a body.

  According to a third aspect of the present invention, there is provided a capacitor connected to the central conductor, the electrode pattern formed on the microwave magnetic body according to the second aspect of the invention, and a ferrite magnet that applies a DC magnetic field to the microwave magnetic body. This is a non-reciprocal circuit device.

  The ferrite magnet preferably has a residual magnetic flux density Br of 420 mT or more and a temperature coefficient of −0.15% / ° C. to −0.25% / ° C.

According to the present invention, can be fired at a low temperature of 850 ° C. or higher 920 ° C. or less, can be simultaneously fired with the low-resistance metal material, no secondary phase of the product also in Bi-substituted, ferromagnetic resonance half-width A polycrystalline ceramic magnetic material having a small ΔH and dielectric loss tan δ, a microwave magnetic material, and a nonreciprocal circuit device using the same can be provided.

Polycrystalline ceramic magnetic material of the present invention, the table main component, in general formula _{(Y 3.0-x-y Bi} x Ca y) (Fe 5-α-β-γ In α Al β Vγ) O 12 And the values of x, y are 0.4 <x ≦ 0.9, 0.5 ≦ y ≦ 1.2, and the values of α, β, γ are 0 ≦ α ≦ 0. .4,0 ≦ β ≦ 0.45,0.25 ≦ γ ≦ 0.6, but be in the range of 0.1 ≦ α + β ≦ 0.75, wherein the Cu及beauty Z r as a sub-component, its The content of Cu is CuO ≦ 0.8 wt% in terms of CuO and Zr is Z rO ₂ ≦ 0.8 wt% in terms of ZrO ₂ with respect to 100 parts by weight of the main component, and has a garnet structure. It is a polycrystalline ceramic magnetic material that has a phase as a main component and is sintered at a temperature of 850 ° C. or higher and 920 ° C. or lower .

  The temperature characteristics of the sintering temperature, the ferromagnetic resonance half width ΔH, the dielectric loss tan δ, the saturation magnetization 4πMs, the saturation magnetization 4πMs are greatly influenced by the main component composition of the polycrystalline ceramic magnetic material. If the composition falls outside the composition range of the invention, the following problems occur.

Bi contributes to low temperature sintering. When x is x = 0.4, sintering at less than 980 ° C. becomes difficult. Further, when x> 1.5, sintering at 850 ° C. or more and less than 980 ° C. is possible, but a heterogeneous phase is likely to occur in the sintered body, and dielectric loss tan δ is tan δ> 15 × 10 ⁻⁴ and ferromagnetic resonance. The half-value width ΔH is remarkably increased as ΔH> 10000 (A / m). For this reason, x is preferably 0.4 <x ≦ 1.5. Preferably, 0.5 ≦ x ≦ 0.9.

  Ca is added together with V described later, and contributes to preventing the low melting point V from evaporating during sintering. In order to exert such an effect, y is preferably 0.5 ≦ y ≦ 1.2.

In, Al, and V contribute to the adjustment of the temperature coefficient αm of the saturation magnetization 4πMs and the low-temperature sintering. The values of α, β, and γ are within the range of 0 ≦ α ≦ 0.4, 0 ≦ β ≦ 0.45, 0.25 ≦ γ ≦ 0.6, and 0.1 ≦ α + β ≦ 0.75, respectively. It is preferable to do this. When In, Al, and V are less than the above range, sintering at less than 980 ° C. becomes difficult. If it is less than the above range, the saturation magnetization 4πMs becomes 4πMs> 130 (mT), and the magnetic force of the permanent magnet having a predetermined shape is insufficient. In many cases, the saturation magnetization 4πMs becomes 4πMs <60 (mT), and the temperature characteristics with the permanent magnet cannot be compensated.
In addition, In and Al are preferably 0.1 ≦ α + β ≦ 0.75 in total. When α + β < 0.1 , the dielectric loss tan δ is remarkably increased as tan δ ≧ 15 × 10 ⁻⁴ and the ferromagnetic resonance half width ΔH is ΔH> 10000 (A / m). Furthermore, if 0.75 <α + β, the temperature coefficient of saturation magnetization 4πMs is αm <−0.38 (% / ° C.), and the absolute value of the temperature coefficient αm is large, so that the temperature characteristics with the permanent magnet are compensated. I can't.

  Further, the subcomponent in the polycrystalline ceramic magnetic material of the present invention contributes to low-temperature sintering, but if the composition is out of the composition range of the present invention, the following problems occur.

First, when CuO is more than 0.8% by weight based on the main component, sintering at a low temperature becomes possible, but a heterogeneous phase is easily generated in the sintered body, and dielectric loss tan δ is tan δ ≧ 15 × 10 ⁻⁴ , and The ferromagnetic resonance half width ΔH is remarkably increased as ΔH> 10000 (A / m). Therefore, it is desirable CuO is C uO ≦ 0.8% by weight with respect to the main component. Preferably, 0.2 wt% ≦ CuO ≦ 0.5 wt%.

On the other hand, if ZrO ₂ is larger than 0.80% by weight with respect to the main component, a heterogeneous phase is likely to occur in the sintered body, and the ferromagnetic resonance half width ΔH increases as ΔH> 10000 (A / m). Therefore, it is desirable ZrO ₂ is Z rO ₂ ≦ 0.80% by weight with respect to the main component. Preferably, 0.05 wt% ≦ ZrO ₂ ≦ 0.30 wt%.

With the above component composition, sintering can be performed at a low temperature of 850 ° C. or more and 920 ° C. or less, the saturation magnetization 4πMs is 60 mT to 130 mT, and the temperature coefficient αm is −0.38% / ° C. to −0.2. It is possible to obtain a polycrystalline ceramic magnetic material having a ferromagnetic resonance half-value width ΔH of 8200 A / m or less.
Therefore, the polycrystalline ceramic magnetic material of the present invention can be integrally sintered using a metal material having high conductivity such as silver as an internal electrode. Therefore, it is possible to suppress a loss due to the high Q value of the magnetic material and the electric resistance of the internal electrode, and to construct a microwave magnetic body with extremely small loss. As a result, it can be applied to microwave nonreciprocal circuit elements such as isolators and circulators to achieve excellent microwave characteristics and low loss.

Hereinafter, examples will be described in detail.
As starting materials, yttrium oxide (Y ₂ O ₃ ) having a purity of 99.0% or more, calcium carbonate (CaCO ₃ ), bismuth oxide (Bi ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), indium oxide (In ₂ O) ₃ ), vanadium oxide (V ₂ O ₅ ) and aluminum oxide (Al ₂ O ₃ ) were prepared, and these were weighed so as to have the composition ratio shown in Table 1, and ion-exchanged water so that the slurry concentration was 40%. And wet mixed in a ball mill for 20 to 50 hours, and then dried. The dried powder was calcined by holding at a temperature of 800 ° C. to 900 ° C. for 1.5 hours to 2 hours. In addition, calcination is set to a temperature lower by 50 ° C. to 80 ° C. than the sintering temperature in the subsequent sintering step.

Next, copper oxide (CuO) and zirconium oxide (ZrO ₂ ) are prepared as auxiliary components, and these are weighed so as to have the composition ratio shown in Table 1 with respect to the base material powder obtained as described above. In addition, ion-exchanged water was added to a slurry concentration of 40%, wet pulverized for 20 to 30 hours with a ball mill, and then dried to obtain a magnetic ceramic composition. The average particle size of the powder obtained as described above was adjusted to 0.5 to 2.0 μm. Even when the auxiliary component was added at the time of weighing the main component, the same effect was obtained.

Then, the granulated powder obtained by adding and kneading a binder solution in the magnetic ceramic composition obtained as described above, the molded body under pressure at a pressure from 1 ton / cm ² of 2 ton / cm ² did. This was fired in the air at a temperature of 900 ° C. to 980 ° C. for 8 hours to obtain a sintered body.

  Next, a dielectric cylindrical resonator was fabricated using the obtained sintered body, and dielectric loss tan δ was measured by the Hack-Coleman method. Moreover, the saturation magnetization Ms of the sample for evaluation was measured using a vibration type magnetometer. Further, the obtained sintered body was processed into a thin disc shape with a thickness of 0.15 mm to 0.25 mm, and the ferromagnetic resonance half width ΔH was measured by a short-circuited coaxial line method. The results are shown in Table 1.

The asterisks shown in Table 1 are comparative examples outside the scope of the invention, and all other examples are examples within the scope of the invention. As shown in Table 1, Sample No. No. 1 does not contain subcomponents, so the firing temperature is as high as 980 ° C. Sample No. 2 and 3, CuO is subcomponent since departing from the scope, the ferromagnetic resonance half-width [Delta] H is increased and ΔH> 10000 (A / m) . Further, a heterogeneous phase is likely to occur in the sintered body, and the dielectric loss tan δ increases as tan δ ≧ 15. Sample No. Since ZrO ₂ in a subcomponent 4,5 is out of range, the ferromagnetic resonance half-width [Delta] H is increased and ΔH> 10000 (A / m) . In the examples within the scope of the present invention, the dielectric loss tan δ is tan δ ≦ 15 × 10 ⁻⁴ and the ferromagnetic resonance half-value width ΔH is ΔH ≦ 10000 (A / m) without causing a heterogeneous phase in the sintered body.

In the examples within the scope of the present invention, a dense sintered body can be obtained at a temperature of 850 ° C. or more and 920 ° C. or less , and the dielectric loss tan δ is tan δ ≦ 15 × 10 ⁻⁴ and the ferromagnetic resonance half width. ΔH is ΔH <10000 (A / m). Further, the temperature coefficient αm of saturation magnetization 4πMs from −20 ° C. to 60 ° C. becomes −0.38% / ° C. to −0.2% / ° C., and the temperature characteristics with the permanent magnet can be compensated.

A microwave magnetic material made of a polycrystalline ceramic magnetic material according to the present invention and a nonreciprocal circuit device using the same will be described. FIG. 1 is a perspective view showing the appearance of a microwave magnetic body (central conductor assembly) used in one embodiment of the present invention. FIG. 2 is an exploded perspective view of the central conductor assembly, and FIG. 3 is an exploded perspective view of a non-reciprocal circuit device according to an embodiment of the present invention.
As the basic configuration of the nonreciprocal circuit element, a central conductor assembly 4, a capacitor multilayer body 5 in which the central conductor assembly 4 is incorporated in a central through hole, and the capacitor multilayer body 5 are incorporated. A resistor 90 formed of a chip or a resistive film, a permanent magnet 3 for applying a DC magnetic field to the central conductor assembly 4, and a metal upper case 1 that also serves as a magnetic yoke, as well as a lower case 2. Between the capacitor multilayer body 5 and the lower case 2, a resin base 6 having a connection terminal to the mounting substrate and a connection electrode for connecting the central conductor assembly 4 and the capacitor multilayer body 5 is disposed.

The central conductor assembly 4 is formed by laminating and arranging a central conductor on a rectangular microwave magnetic body having first and second main surfaces facing each other and side surfaces connecting the main surfaces.
The manufacturing process of the central conductor assembly 4 is as follows. First, Bi ₂ O ₃ , Y ₂ O ₃ , CaCO ₃ , Fe ₂ O ₃ , In ₂ O ₃ , V ₂ O ₅ are used as starting materials, and the main components are represented by the general formula (Y _1.55 Bi _0.55 Ca _{0 .9} ) (Fe _3.95 In _0.3 Al _0.3 V _0.45 ) O ₁₂ (Atom%) (Sample No. 16) and weighed the starting materials in a ball mill. The obtained slurry was dried, calcined at a temperature of 850 ° C., and wet pulverized with a ball mill.
Next, copper oxide (CuO) and zirconium oxide (ZrO ₂ ) were prepared as subcomponents, and 0.35% by weight of CuO, 0.35% by weight of ZrO _{2 with} respect to 100 parts by weight of the base material powder obtained as described above. Weighed to 1% by weight, added ion exchanged water to a slurry concentration of 40%, wet crushed with a ball mill for 20 to 30 hours, and then dried to obtain a polycrystalline ceramic magnetic material. . The average particle size of the powder obtained as described above was adjusted to 0.5 to 2.0 μm.
The magnetic material powder, an organic binder, a plasticizer, and an organic solvent were mixed by a ball mill to adjust the viscosity, and then a magnetic ceramic green sheet having a thickness of 40 μm to 250 μm was prepared by a doctor blade method.

  Via holes of φ0.2 to φ0.4 (indicated by black circles in the figure) are formed by laser processing on the obtained ceramic green sheet, and the conductive paste that becomes the central conductor is printed, and further green sheets are stacked. After heating to 80 ° C. and thermocompression bonding at a pressure of 12 MPa to form a laminate, after cutting the laminate with a dicing saw or steel blade, for example, to a predetermined size and shape, at 980, Baked for 2 hours. The via hole is filled with an Ag conductor, and the center conductors 44a to 44c are connected to the ground electrode Gnd and the input / output electrodes In, Out, and Load. In this way, the central conductors 44a to 44c cross each other at an equal angle while keeping insulation from each other, and the ground electrode GND and the input / output electrodes In, Out, and Load are provided as an LGA (Land Grid Array) on the second main surface 43f. A central conductor assembly 4 was obtained.

  The capacitor laminate 5 has an input capacitance electrode C1, an output capacitance electrode C2, a load capacitance electrode C3 for forming a matching capacitance, and a ground electrode Gnd on which a termination resistor 90 is disposed on the upper surface and inside the laminate. Has been. In addition, input / output electrodes In, Out, Load, and a ground electrode Gnd for electrical connection to the resin base 6 are provided on the back surface of the capacitor laminate 5.

  The resin base 6 is manufactured by, for example, using a copper plate having a thickness of 0.1 mm and integrally molding the copper plate and the liquid crystal polymer by injection molding. On the upper surface of the resin base 6, that is, on the connection surface side with the capacitor laminate 5, connection electrodes In, Out, Load, and GND are formed of a conductor plate, and are configured in a planar shape including the resin portion. In addition, the connection electrodes In, Out, Load, GND are formed on the same plane, the connection electrodes GND, Load and the terminal G, and the connection electrodes In, Out are configured by the same conductor plate, respectively, as the terminal electrodes P1, P2. Electrically connected.

  As the permanent magnet, a La-Co substituted ferrite magnet YBM-9BE manufactured by Hitachi Metals, Ltd., which was formed in a square shape was used. This permanent magnet has a residual magnetic flux of 430 mT to 450 mT and a temperature coefficient of the residual magnetic flux density of −0.20% to −0.18%. About the shape of the permanent magnet. Arbitrary shapes such as a disk shape and a hexagonal shape can be adopted. The same applies to the shape of the garnet.

  After the obtained center conductor assembly 4 is placed in the through hole of the capacitor multilayer body 5, it is connected via the connection electrode of the resin base 6, and the permanent magnet 3 is placed on the upper side of the center conductor assembly 4. Was covered with an upper case 1 and a lower case 2 to form a nonreciprocal circuit device. The temperature characteristics of the non-reciprocal circuit element of the present invention were evaluated for the insertion loss. However, the non-reciprocal circuit element having excellent temperature characteristics was obtained with a small variation in frequency at which the insertion loss accompanying temperature change was minimized.

According to the present invention, firing can be performed at a low temperature of 850 ° C. or more and 920 ° C. or less , and simultaneous firing with a low- resistance metal material is possible. It is possible to provide a polycrystalline ceramic magnetic material, a microwave magnetic material, and a nonreciprocal circuit device using the same, in which a Bi substitution type does not generate a different phase and has a small ferromagnetic resonance half width ΔH and a small dielectric loss tan δ. As a result, it can be applied to microwave nonreciprocal circuit elements such as circulators and isolators to realize excellent microwave characteristics and low loss.

It is a perspective view which shows the external appearance of the microwave magnetic body (center conductor assembly) of the nonreciprocal circuit device based on one Example of this invention. It is a disassembled perspective view of the microwave magnetic body (center conductor assembly) of the nonreciprocal circuit device based on one Example of this invention. 1 is an exploded perspective view of a non-reciprocal circuit device according to one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper case 2 Lower case 3 Permanent magnet 4 Center conductor assembly 5 Capacitor laminated body 6 Resin bases 44a-44c Center conductor

Claims (5)

Main component has a composition represented by the general formula _{(Y 3.0-x-y Bi} x Ca y) (Fe 5-α-β-γ In α Al β Vγ) O 12,
the values of x and y are 0.4 <x ≦ 0.9, 0.5 ≦ y ≦ 1.2,
The values of α, β, and γ are in the range of 0 ≦ α ≦ 0.4, 0 ≦ β ≦ 0.45, 0.25 ≦ γ ≦ 0.6, but 0.1 ≦ α + β ≦ 0.75. And
Include Cu及beauty Z r as a sub-component, the content thereof is, with respect to the main component as 100 parts by weight, C uO ≦ 0.8 wt% of Cu in terms of CuO, Z and rO ₂ ≦ a Zr in terms of ZrO ₂ A polycrystalline ceramic magnetic material characterized by comprising 0.8% by weight of a phase having a garnet structure as a main component and sintering at a temperature of 850 ° C. or higher and 920 ° C. or lower . The saturation magnetization 4πMs is 60 mT to 130 mT, the temperature coefficient αm is −0.38% / ° C. to −0.2% / ° C., and the ferromagnetic resonance half width ΔH is 8200 A / m or less. The polycrystalline ceramic magnetic material according to claim 1.   A microwave magnetic body obtained by integrally sintering the polycrystalline ceramic magnetic material according to claim 1 and a conductor paste containing either Ag or an Ag alloy, wherein the inside of the microwave magnetic body And / or an electrode pattern formed of the conductive paste on a surface thereof.   An electrode pattern formed on the microwave magnetic body according to claim 3 is used as a central conductor, and a capacitor connected to the central conductor and a ferrite magnet that applies a DC magnetic field to the microwave magnetic body are provided. Non-reciprocal circuit element.   The nonreciprocal circuit according to claim 4, wherein the ferrite magnet has a residual magnetic flux density Br of 420 mT or more and a temperature coefficient of -0.15% / ° C to -0.25% / ° C. element.

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