KR20020085761A - Dielectric ceramic composition, ceramic capacitor using the same and process of producing thereof - Google Patents

Abstract

PURPOSE: A microwave dielectric ceramic composition of the xBaO-ySm2O3-zTiO2 system and a ceramic capacitor using the composition are provided, which has high dielectric constant, large Q value at high frequency, low temperature coefficient of resonant frequency, and low temperature sintering. CONSTITUTION: The dielectric ceramic composition comprises xBaO-ySm2O3- zTiO2(0.05<=x<=0.30, 0.05<=y<=0.20 0.65<=z<=0.75, and x=y+z=1) as main components, 0.05-8wt.% of CuO, 0.01-5wt.% of ZnO and 0.1-10wt.% of glass composition based on ZnO-SiO2 or Li2O-Al2O3-SiO2 as auxiliary components, and optionally 0.005-2.5wt.% of rare earth oxides such as Y2O3, Ho2O3, Dy2O3, Yb2O3 and Ce2O3, more than 3wt.% of PbO, and more than 3wt.% of Bi2O3 or Al2O3. The ceramic capacitors are produced by mixing components, bulk-forming, electroding and sintering at 850-1050deg.C, and the ceramic multilayer capacitors are produced by mixing components, sheet-forming, electroding, multilayering, and sintering at 850-1050deg.C. The lowered sintering temperature compared with conventional sintering temperature, 1200-1400deg.C, enables use of electrodes made of non metals(Cu, Ni, W, Mo, etc.) or carbon-based materials, which results in low-cost production.

Description

Dielectric magnetic composition, magnetic capacitor using same and method for manufacturing same {Dielectric ceramic composition, ceramic capacitor using the same and process of producing etc}

The present invention relates to a dielectric magnetic composition, a magnetic capacitor using the same, and a method of manufacturing the same. In particular, the dielectric magnetic composition having a high dielectric constant, a low dielectric loss, high dielectric resistance, and stable characteristics in the microwave region, and a method of manufacturing the same. The present invention relates to a magnetic capacitor, and further relates to a method of manufacturing a dielectric magnetic composition and a magnetic capacitor capable of lowering the manufacturing cost by enabling the use of a non-metal as an electrode material since the firing at a lower temperature is realized.

In recent years, mobile devices, such as mobile phones, automobile phones, personal radios, and the like, and satellite devices, such as satellite broadcasting receivers, are rapidly progressing in electronic devices used in high frequency areas such as myriad waves and microwaves. In devices such as capacitors, filters, or resonators mounted in electronic devices used in the high frequency region, improvement of high frequency characteristics is increasingly required.

The high frequency characteristics required for a device used in the high frequency region include a large relative dielectric constant, a large Q value, a small change in temperature of the dielectric constant, and further low temperature sintering.

For example, in the case of the resonator used in the high frequency region, the wavelength of the dielectric is often shortened in proportion to the inverse of the square root of the dielectric constant. If the dielectric constant is large, the length of the resonator may be shortened in proportion to the inverse of the square root of the dielectric constant. Because it can.

In the high-frequency dielectric material, the quality factor Q defined by Q = 1 / tanδ is used as a criterion for evaluating the dielectric energy loss due to the phase delay (δ) by frequency. It means that the loss is small.

Furthermore, in devices such as capacitors, filters, or resonators, since the temperature change of the resonance frequency is made very small, it is preferable that the temperature change of the dielectric constant is also very small (that is, the temperature coefficient TC is small).

In addition, in order to realize miniaturization of electronic devices, surface-mounted devices incorporating conductor electrodes therein have become mainstream. In this case, Ag or Cu is preferably used as a conductive electrode in order to suppress characteristic loss of the device. . However, Ag or Cu has a low melting point, and when producing a dielectric porcelain, Ag or Cu has a difficulty in withstanding high temperature sintering at 1200 to 1400 ° C. Therefore, if it can be sintered at a lower temperature of 1000 ° C. or lower, it is preferable also from the viewpoint of electrode configuration or from the viewpoint of energy cost.

Background Art Conventionally, magnetic capacitors (ceramic capacitors) using ceramics' dielectric characteristics are known as small and large capacity capacitors. The magnetic capacitor is rutile (rutile) Type of TiO _2, perovskite and teuhyeong _{BaTiO 3, MgTiO 3, CaTiO 3} , SrTiO 3 , etc. For one thing, or combinations thereof made of a dielectric material of the capacitor having the characteristics desired.

In addition, BaO-Nd ₂ O ₃ -TiO ₂ -PbO as a magnetic capacitor having quality characteristics such as large dielectric constant, large Q value, and small temperature change of dielectric constant required for a device used in a high frequency region. Systems (see Japanese Patent Application Laid-Open No. 56-26321) and BaO-Nd ₂ O ₃ -TiO ₂ -Bi ₂ O ₃ systems (see Japanese Patent Application Laid-Open No. 59-51091).

Further, improvements in low temperature firing include BaO-Nd ₂ O ₃ -TiO ₂ -CuO-ZnO (see Japanese Patent Application Laid-Open No. 2000-26471) or BaO-Nd ₂ O ₃ -Sm ₂ O ₃ -PrO ₂ -TiO. (See Japanese Patent Application Laid-Open No. 2000-290068) and the like are known.

Magnetic capacitors are classified into single layer type and stacked type.

Single-layer magnetic capacitors are formed by pressing the above-described material powder into shaped bodies such as pellets (plates), rods (cylindrical forms), chips (squares), and the like, and the shaped bodies at a temperature of 1200 to 1400 캜 in the air. It can be obtained by firing to form a sintered body and forming electrodes on both surfaces of the sintered body.

In the multilayer magnetic capacitor, the above-described material powder, organic binder and organic solvent are kneaded to form a slurry. The slurry is formed into a sheet by a doctor blade method and then degreased into a green sheet. After printing the electrode which consists of noble metals, such as Pt and Pd, on this green sheet, these green sheets are laminated | stacked and pressed in the thickness direction, and it is made into a laminated body, and this laminated body is obtained by baking at the temperature of 1200-1400 degreeC in air | atmosphere. Can be.

However, the above-described conventional magnetic capacitors have the disadvantages of low relative dielectric constant, high dielectric loss, and low insulation resistance in the microwave region. As described above, in the device used in the high frequency region, a compact sintered body having excellent electrical characteristics is required. In order to obtain such a compact sintered compact, firing at a high temperature of 1200 to 1400 ° C is required, resulting in an increase in energy cost and a factor of increasing cost. In addition, especially in a multilayer magnetic capacitor, when a base metal is used as an electrode material, since the base metal is oxidized at high temperature firing to form a high resistance layer between ceramic layers, it is necessary to use a precious metal material such as Pt or Pd that is stable even at high temperatures. There is a problem that inhibits the cost.

Even in the well-known dielectric ceramic compositions for the high frequency region described above, the sintering temperature is at most 920 ° C., the high dielectric constant and Q value are small, the temperature change of the dielectric constant is small, and all the characteristics of low temperature sintering can be achieved. Combined dielectric self compositions have not been obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a high dielectric constant, a low dielectric loss, stable characteristics, and stable firing at low temperatures in a small and large capacity magnetic capacitor used in the microwave region. It is an object of the present invention to provide a dielectric magnetic composition, a magnetic capacitor using the same, and a method of manufacturing the same, which can use a non-metal, and can significantly lower the manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the single layer magnetic capacitor of 1st Embodiment of this invention.

2 is a cross-sectional view showing a multilayer magnetic capacitor of a second embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

1 ..... Dielectric self-composition Sintered body 2 ..... Terminal electrode

3 ..... lead wire 4 ..... epoxy resin

11 ..... Dielectric self composition sintered body 12 ..... Internal electrode

13, 14 ..... Terminal electrode

In order to solve the above problems, the dielectric magnetic composition of the present invention is xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75) is a dielectric ceramic composition formed by adding 0.05 to 8% by weight of CuO, 0.01 to 5% by weight of ZnO, and 0.1 to 10% by weight of glass composition as a minor component.

By using such a dielectric magnetic composition, it is possible to realize high dielectric constant, good temperature characteristic and high quality coefficient, and to stabilize the characteristic in high frequency region such as microwave region. Reliability is also improved in the high frequency range. In addition, low-temperature baking is possible, non-metal electrode material can be used, manufacturing cost can be significantly reduced.

Since it does not contain finite PbO, it is possible to make a product which is good for an environment.

In the dielectric magnetic composition of the present invention, yttrium oxide (Y ₂ O ₃ ), holmium oxide (Ho ₂ O ₃ ), dysprosium oxide (Dy ₂ O ₃ ), and ytterbium oxide (Yb ₂ O) with respect to the cast product of the dielectric magnetic composition. ₃ ) or 0.005 to 2.5% by weight of at least one rare earth element compound selected from cerium oxide (Ce ₂ O ₃ ) may be added. By adding these traces of rare earth element compounds, a useful effect of improving the temperature coefficient (TC) of the Q value and ratio conductivity is obtained.

In the dielectric magnetic composition of the present invention, a small amount of PbO or Bi ₂ O ₃ of ₃ % by weight or less can be added to further improve low-temperature sintering.

In the dielectric magnetic composition of the present invention, it is possible to obtain a dielectric magnetic composition in which 0.005 to 2 parts by weight of aluminum oxide (Al ₂ O ₃ ) is added to 100 parts by weight of the dielectric magnetic composition containing the subcomponent. By adding a small amount of Al ₂ O ₃ , the Q characteristics can be further improved.

In the dielectric magnetic composition of the present invention, any of ZnO-SiO ₂ -based glass or Li ₂ O-Al ₂ O ₃ -SiO ₂ -based glass can be used as the glass composition. By using these glass compositions, the firing temperature can be lowered to 850 ° C or lower and 850 ° C.

The magnetic capacitor of the present invention forms a terminal electrode on both surfaces of the sintered body of the dielectric magnetic composition of the present invention to form a magnetic capacitor. The magnetic capacitor of the present invention may also be a magnetic capacitor in which a sintered body molded into a sheet form of the dielectric magnetic composition of the present invention and an electrode are alternately stacked.

In the magnetic capacitor of the present invention, as the electrode, non-metals such as Cu, Ni, W, Mo, or carbon-based materials such as graphite can be used. When these materials are used as electrodes, they are inexpensive and oxidized at firing so as not to form a high resistance layer between the magnetic compositions.

The method of manufacturing the dielectric magnetic composition of the present invention is xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75). 0.05-8 wt% of CuO, 0.01-5 wt% of ZnO, and 0.1-10 wt% of the glass composition are added to the formed cast product, and 0.005-2.5 wt% of Y ₂ O ₃ , as an additive, if necessary. At least one rare earth element oxide selected from Ho ₂ O ₃ , Dy ₂ O ₃ , Yb ₂ O _3, or Ce ₂ O ₃ , or powder to which 0.005-2 parts by weight of Al ₂ O ₃ is added, It is set as a sheet-like molded object, and the method of shape | molding this molded object at the temperature of 850-1050 degreeC is employ | adopted.

According to the method for producing the dielectric ceramic composition of the present invention, the firing temperature can be lowered by 350 ° C. or more than before without damaging the electrical characteristics.

The method of manufacturing the magnetic capacitor of the present invention comprises xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75). To the cast product, 0.05 to 8% by weight of CuO, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of glass composition are added to the cast product, and 0.005 to 2.5% by weight of Y ₂ O ₃ , Ho as an additive, if necessary. ₂ O _3, Dy ₂ O _3, Yb ₂ O ₃ or Ce ₂ O rare earth element oxides on the at least one member selected from the _3, or 0.005 to 2 and then press-molding the powder by adding the parts by weight of Al ₂ O ₃ as a bulk An electrode is formed on a pair of main surfaces of the bulk molded body, and then the molded body is fired at a temperature of 850 ° C to 1050 ° C, which is a method for producing a magnetic capacitor. According to the manufacturing method of the magnetic capacitor of the present invention, the firing temperature can be lowered by 350 ° C. or more without impairing the electrical characteristics.

Another method of manufacturing the magnetic capacitor of the present invention is xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75). 0.05-8 wt% of CuO, 0.01-5 wt% of ZnO and 0.1-10 wt% of the glass composition are added to the formed cast product, and 0.005-2.5 wt% of Y ₂ O ₃ , as an additive, if necessary. At least one rare earth element oxide selected from Ho ₂ O ₃ , Dy ₂ O ₃ , Yb ₂ O _3, or Ce ₂ O ₃ , or powder containing 0.005 to 2 parts by weight of Al ₂ O ₃ , was press-molded into a sheet. Thereafter, an electrode is formed on one main surface of the sheet-shaped molded article, and then the molded articles are laminated and pressed in a plurality of thickness directions to form a laminate, and the laminate is fired at a temperature of 850 to 1050 ° C. It is a manufacturing method of a capacitor.

According to the manufacturing method of the magnetic capacitor, the firing temperature can be lowered to 350 ° C. or lower without impairing the electrical characteristics, and a multilayer magnetic capacitor can be obtained.

Hereinafter, the present invention will be described in detail.

First, the reason for composition limitation of the dielectric magnetic composition of the present invention will be described.

The dielectric magnetic composition of the present invention is composed of three components of barium oxide (BaO), samarium oxide (Sm ₂ O ₃ ), and titanium oxide (TiO ₂ ) as a cast product. The molar ratios x, y and z of BaO, Sm ₂ O ₃ and TiO ₂ are 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20 and 0.65 ≦ z ≦ 0.75 (where x + y + z = 1). .

If BaO is 5 mol% or less, the relative dielectric constant and Q value are lowered. Moreover, when BaO is 30 mol% or more, the dielectric constant becomes high, causing an increase in the temperature coefficient TC of the dielectric constant and a decrease in the Q value.

If Sm ₂ O ₃ is 5 mol% or less, the dielectric constant is increased, but the temperature coefficient TC of the dielectric constant is increased, resulting in a decrease in the Q value. In addition, when Sm ₂ O ₃ is 20 mol% or more, low-temperature sintering at the time of manufacture is difficult, and the dielectric constant decreases.

When TiO ₂ is 65 mol% or less, the temperature coefficient TC of the dielectric constant increases, which causes a decrease in the Q value. In addition, when TiO ₂ is 75 mol% or more, low temperature sintering at the time of manufacture becomes difficult.

Therefore, the appropriate molar ratio range of the cast product is defined as above.

The dielectric ceramic composition of the present invention, in addition to the above cast product, as a minor component, copper oxide (CuO) as the main component, 0.05 to 8% by weight, zinc oxide (ZnO) as the main component and 0.01 to 5% by weight and the glass composition as the main component 0.1 to 10% by weight of each of these subcomponents act as a sintering aid, and by containing these subcomponents in an appropriate range, the firing temperature is adjusted to 850 from a conventional high temperature of 1,200 to 1,400 ° C. It is possible to bake at a low temperature of 1050 캜.

When CuO is 0.05 weight% or less, the effect of low temperature sintering is not acquired, and it causes a fall of Q value. In addition, at 8 wt% or more, the Q value and the insulation resistance are reduced.

When ZnO is 0.01 wt% or less, the effect of low temperature sintering is not obtained, and the Q value is lowered. On the other hand, at 5 wt% or more, the relative dielectric constant and Q value are lowered.

In addition, in the dielectric magnetic composition of the present invention, the glass composition does not adversely affect the properties even if it is added, and the wettability with the components of the cast product is good, and the glass that softens and / or melts at a temperature of 850 to 1050 ° C is preferable. Do. For example, Bi ₂ O ₃ -SiO ₂ -based glass or Li ₂ O-Al ₂ O ₃ -SiO ₂ -based glass or the like is used.

The glass composition has an effect of promoting low-temperature sintering and is added as a sintering aid. 0.1-10 weight% is appropriate for this addition amount. The reason for this is that when the added amount is 0.1% by weight or less, there is no effect of promoting low-temperature sinterability, and when it is 10% by weight or more, the Q value decreases and the insulation resistance decreases.

Therefore, the component range of a subcomponent is set as mentioned above.

In the dielectric magnetic composition of the present invention, yttrium oxide (Y ₂ O ₃ ), holmium oxide (Ho ₂ O ₃ ), dysprosium oxide (Dy ₂ O ₃ ), as a first additive to the cast product of the dielectric magnetic composition, At least one rare earth element compound selected from ytterbium oxide (Yb ₂ O ₃ ) or cerium oxide (Ce ₂ O ₃ ) may be added in a range of 0.005 to 2.5% by weight.

By adding these rare earth element oxides in a small amount, it has a useful effect of improving the temperature coefficient (TC) of the Q value and the relative dielectric constant. Although the Q value can be increased by adding a rare earth element oxide, the effect is not recognized when the added amount is 0.005% by weight or less, and low temperature sintering property is inhibited by 2.5% by weight or more.

In the dielectric magnetic composition of the present invention, a small amount of PbO or Bi ₂ O ₃ can be added as the second additive. Small amounts of PbO or Bi ₂ O ₃ have the effect of promoting low temperature sintering and improve the relative dielectric constant. If the added amount is more than 3% by weight, the lowering of the insulation resistance, the lowering of the Q value, or the like is not preferable.

In the dielectric magnetic composition of the present invention, aluminum oxide (Al ₂ O ₃ ) may be added as the third additive in addition to the second additive. By adding a small amount of Al ₂ O ₃ , the quality factor (Q value) can be increased. The appropriate addition amount of Al ₂ O ₃ is made 0.005 to 2 parts by weight based on 100 parts by weight of the dielectric magnetic composition of the cast and sub-compositions. Or when it contains the said 1st additive, it will be 0.005-2 weight part with respect to 100 weight part of dielectric ceramic compositions which become a cast product, a subcomposition, and a 1st additive. The amount of Al ₂ O ₃ added can not exert the effect at 0.005 parts by weight or less, and at 2 parts by weight or more, the Q value is rather reduced. Therefore, the appropriate addition amount of Al ₂ O ₃ is made into 0.005-2 weight part.

In order to obtain the dielectric ceramic composition of the present invention, each component of the main component composition is weighed in a predetermined amount, housed in a ball mill with a dispersion medium made of a predetermined amount of an organic solvent such as water, ethanol or acetic acid, For example, it is mixed and pulverized for 4 to 24 hours, after which dehydration or an organic solvent is followed by drying. Subsequently, this dry powder is calcined for 1 to 24 hours at a temperature of 1000 to 1400 ° C.

Subsequently, an additive is added to the calcined main component as necessary, and additives are added as necessary. A dispersion medium such as water is added to uniformly mix and pulverize the powder, and an average particle diameter of 1 탆 or less is obtained. The fine powder is then dehydrated and calcined at a second temperature of 600 to 800 ° C. for 1 to 15 hours. Then, it grind | pulverizes until an average particle diameter becomes 0.8 micrometer or less.

Next, an appropriate amount of an organic binder and the like are added to the calcined powder obtained and mixed uniformly. For example, a pellet of 20 mm in diameter and 2 mm in thickness or a rod or chip is press-molded, and then subjected to 850 to 1050 ° C in air. Baking at temperature for 1 to 24 hours to obtain a dielectric self-composition.

As the organic binder, an aqueous solution of ethyl cellulose, an aqueous acrylic resin solution (acrylic binder), or the like can be used in addition to the aqueous PVA (polyvinyl alcohol) solution.

The dielectric ceramic composition of the present invention is characterized by being fired at a lower temperature than conventionally at 850 to 1050 캜. The dielectric magnetic composition obtained by the above has a high relative dielectric constant in the microwave region, has a low dielectric loss, and further has a high insulation resistance, which is extremely useful for devices including capacitors for the microwave region.

Next, the magnetic capacitor of the present invention will be described.

The magnetic capacitor of the present invention uses the above-described dielectric magnetic composition of the present invention, and has a high dielectric constant, a low dielectric loss, and a low dielectric constant temperature coefficient and stable characteristics even in a high frequency band such as microwave. to be.

In addition, since the dielectric magnetic composition is used, it is possible to bake at a lower temperature than that of the conventional 850 to 1050 ° C., and the manufacturing cost can be lowered along with the use of an inexpensive nonmetal or carbon-based material as the internal electrode.

The base metal contains one or two or more selected from highly reliable metals such as copper (Cu), nickel (Ni), tungsten (W), molybdenum (Mo) and the like as conductors. One metal or alloy is preferred.

As the carbonaceous substance, carbon (amorphous carbon), graphite (quartz, graphite), or a mixture thereof is preferable.

The magnetic capacitor of the present invention is formed by forming a terminal electrode of the above-described nonmetal on the surface of the sintered body of the dielectric magnetic composition of the present invention. Hereinafter, the magnetic capacitor of the present invention will be described with reference to embodiments.

[First Embodiment]

1 is a cross-sectional view showing a magnetic capacitor (ceramic capacitor) which is the first embodiment of the present invention, and shows an example of a single-layer type magnetic capacitor. In the drawings, reference numeral 1 denotes a bulk magnetic dielectric composition according to the present invention, 2 denotes a terminal electrode formed on both sides of the dielectric magnetic composition 1, 3 denotes a lead wire connected to the terminal electrode 2, and 4 denotes a dielectric magnetic composition 1. And an epoxy resin for sealing the terminal electrode (2).

The dielectric magnetic composition 1 is a cast product composed of xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75). 0.05 to 8% by weight of CuO, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of glass composition are added to the subcomponent, and 0.005 to 2.5% by weight of Y ₂ O ₃ , Ho ₂ O ₃ , The powder magnetic composition formed by adding at least one rare earth element oxide selected from Dy ₂ O ₃ , Yb ₂ O _3, or Ce ₂ O ₃ , or 0.005 to 2 parts by weight of Al ₂ O ₃ , is press-molded in a plate shape to form 850 to It is baked for 1 to 24 hours at 1050 ℃

As the terminal electrode 2, a highly reliable material such as Ag, Ag-10Pd alloy, or the like having a characteristic as a conductor can be used. Alternatively, for example, a carbonaceous material such as Cu, Ni, W, Mo or an alloy thereof, or carbon, graphite, or a mixture thereof may be used.

Next, the manufacturing method of this magnetic capacitor is demonstrated.

First, as described above, a plate-shaped sintered body of a dielectric magnetic composition having a specific composition is produced, and terminal electrodes are formed on both sides of the plate-shaped sintered body.

The terminal electrode may be an organic binder, a dispersant, an organic solvent, a reducing agent, or the like, in a powder of a conductive material such as a non-metal such as Cu, Ni, W, Mo, or an alloy thereof, or carbon, graphite, a mixture of carbon and graphite. A predetermined amount is added and kneaded, a conductive paste having a predetermined viscosity is printed in a predetermined pattern, and fired in an inert gas atmosphere such as nitrogen gas or a nitrogen-hydrogen reducing gas atmosphere to form a terminal electrode.

This magnetic capacitor has a relative dielectric constant?, A quality factor Q, and a dielectric constant TC, which is stable even in the high frequency region.

Second Embodiment

It is sectional drawing which shows the laminated magnetic capacitor which is 2nd Embodiment of this invention.

In the drawing, reference numeral 11 denotes a sheet-like dielectric magnetic composition sintered body, 12 is a thin-thickness internal electrode, 13 and 14 are terminal electrodes, and 8 layers of dielectric ceramic composition sintered body 11 and 7 are internal electrodes 12. Laminated by alternating layers

The dielectric ceramic composition sintered body 11 has the same xBaO-ySm ₂ O ₃ -zTiO ₂ as in the first embodiment (where x + y + z = 1, 0.05≤x≤0.30, 0.05≤y≤0.20, 0.65). ≤ z ≤ 0.75), 0.05 to 8% by weight of CuO, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of glass composition are added as a minor component, and 0.005 to 2.5% by weight of Y as necessary. At least one rare earth element oxide selected from ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , Yb ₂ O _3, or Ce ₂ O ₃ , or a dielectric magnetic composition containing 0.005 to 2 parts by weight of Al ₂ O ₃ is added. Press-molded into sheet form and calcined at 850 ~ 1050 ℃ for 1 ~ 24 hours

The internal electrodes 12 and the terminal electrodes 13 and 14 are also molded using the same electrode material as in the first embodiment. The difference from the first embodiment described above is that not one dielectric ceramic composition having an electrode is formed but stacked in a plurality of sheets.

The manufacturing method of the laminated magnetic capacitor will be described. First, as described above, a sheet-like sintered body of a dielectric magnetic composition having a specific composition is produced, and terminal electrodes are formed on both surfaces of the sheet-like sintered body.

To obtain a sheet-like sintered compact, a powder having a specific composition is contained in a ball mill with a predetermined amount of water or a dispersion medium such as an organic solvent such as ethanol or acet, mixed and pulverized for a predetermined time, for example, for 24 hours, and then dehydrated. Alternatively, the organic solvent is dried and then dried.

Next, after adding a predetermined amount of an organic binder and an organic solvent to this dry powder, it is knead | mixed using a Leicaigi, a kneading machine, etc., and it is set as the slurry which has a predetermined viscosity. As the organic binder, an aqueous solution of ethyl cellulose, an aqueous acrylic resin solution (acrylic binder), or the like other than PVA (polyvinyl alcohol) solution can be used.

Next, the slurry is formed into a sheet and degreased by a doctor blade method to form a green sheet, and the internal electrode is formed by using the same conductive paste as in the first embodiment on both surfaces of the dielectric magnetic composition on the green sheet. To form.

The green sheet with internal electrodes thus obtained is laminated in the thickness direction and pressed in the thickness direction to obtain a laminate.

Next, the laminate is calcined for 1 to 24 hours in an inert gas atmosphere such as nitrogen gas or in a nitrogen-hydrogen reducing gas atmosphere at a temperature of 850 to 1050 캜 to obtain a sheet-like dielectric magnetic composition. After that, the terminal electrodes 13 and 14 are formed on both sides, and the whole is covered with an encapsulant such as an epoxy resin to form a stacked magnetic capacitor.

This magnetic capacitor also exhibits stable characteristics in the high frequency region with high relative dielectric constant (ε), quality coefficient (Q value) and small dielectric constant temperature coefficient (TC).

EXAMPLE

Hereinafter, an Example and a comparative example are given and this invention is demonstrated more concretely.

(Example, Comparative Example)

A single layer magnetic capacitor having a structure as shown in Fig. 1 was made.

First, powdered BaO, Sm ₂ O ₃ , and TiO ₂ , which are the main components, are mixed in a predetermined amount so as to have the compositions shown in Tables 1 and ₂ , respectively, and these powdered raw materials are used together with a predetermined amount of water used as a dispersing material. It charged to the ball mill, mixed and pulverized for 6 hours, and dehydrated and dried after that. It was then calcined at 1100 ° C. for 3 hours.

Next, the calcined main component powder was blended with CuO, ZnO, and the glass compositions shown in Tables 1 and 2 as an auxiliary composition, mixed with water, and ground to a fine powder having an average particle diameter of 1 µm or less. Here, ZnO-SiO ₂ -based glass was used as the glass composition. As shown in Table 1 and Table 2, Y ₂ O ₃ , Ho ₂ O ₃ as the first additive, PbO, Bi ₂ O ₃ as the _second additive, and Al ₂ O ₃ as the third additive were added. If the addition of Al ₂ O ₃ is the amount of Al ₂ O ₃ shown in Table 1 and Table 2 was added to the main composition and the additive or mixture of additives, of the second of the first predetermined amount of the above.

Sample Number division Casting component (mol%) Relief ingredient (wt%) Additive 1 (% by weight) Additive 2 (% by weight) Additive 3 (parts by weight) Firing temperature (℃) Example Comparative example BaO Sm ₂ O ₃ TiO ₂ CuO ZnO Grass Y ₂ O ₃ Ho ₂ O ₃ PbO Bi ₂ O ₃ Al ₂ O ₃ One ○ 4 20 76 2.4 0.25 3.0 0 0 0 0 0 900 2 ○ 31 5 64 2.4 0.25 3.0 0 0 0 0 0 900 3 ○ 19 9 72 2.4 0.25 3.0 0 0 0 0 0 900 4 ○ 21 4 75 2.4 0.25 3.0 0 0 0 0 0 900 5 ○ 14 21 65 2.4 0.25 3.0 0 0 0 0 0 900 6 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 880 7 ○ 19 9 72 2.4 0.25 3.0 0 0 0.3 0.05 0 880 8 ○ 19 9 72 2.4 0.25 3.0 0.2 0 0.3 0.05 0 880 9 ○ 19 9 72 2.4 0.25 3.0 0 0.2 0.3 0.05 0 880 10 ○ 19 9 72 2.4 0.25 3.0 0 0 0.3 0.05 0.01 880 11 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0 880 12 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 2.1 880 13 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 830 14 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 1050 15 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 900 16 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 850

Sample Number division Casting component (mol%) Relief ingredient (wt%) Additive 1 (% by weight) Additive 2 (% by weight) Additive 3 (parts by weight) Firing temperature (℃) Example Comparative example BaO Sm ₂ O ₃ TiO ₂ CuO ZnO Grass Y ₂ O ₃ Ho ₂ O ₃ PbO Bi ₂ O ₃ Al ₂ O ₃ 17 ○ 19 9 72 2.4 0.25 11 0.2 0.2 0.3 0.05 0.01 880 18 ○ 19 9 72 2.4 0.25 0.05 0.2 0.2 0.3 0.05 0.01 880 19 ○ 19 9 72 0.04 0.25 3.0 0.2 0.2 0.3 0.05 0.01 880 20 ○ 19 9 72 8.1 0.25 3.0 0.2 0.2 0.3 0.05 0.01 880 21 ○ 19 9 72 2.4 5.1 3.0 0.2 0.2 0.3 0.05 0.01 880 22 ○ 19 9 72 2.4 0.005 3.0 0.2 0.2 0.3 0.05 0.01 880 23 ○ 19 8 76 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 880 24 ○ 19 13 70 2.4 0.25 3.0 0.2 0.2 0.3 0.05 0.01 880 25 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 3.1 0 0.01 880 26 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0 3.1 0.01 880 27 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0 0.4 0.01 900 28 ○ 19 9 72 2.4 0.25 3.0 0.2 0.2 0.38 0 0.01 900 29 ○ 19 9 72 2.4 0.25 3.0 2.6 0.2 0.3 0.05 0.01 880 30 ○ 19 9 72 2.4 0.2 3.0 0.2 2.6 0.3 0.05 0.01 880 31 ○ 19 9 72 2.4 0.25 3.0 0.2 0 0.3 0.05 0.01 880 32 ○ 19 9 72 2.4 0.25 3.0 0 0.2 0.3 0.05 0.01 880

Next, the fine powder was calcined at a second temperature of 650 to 750 ° C. for 3 hours, and then pulverized for 1 to 24 hours using automatic induction to obtain calcined fine powder having an average particle diameter of 0.8 μm or less.

Subsequently, a predetermined amount of organic binder was added to the calcined fine powder and mixed uniformly, and then pelletized into a diameter of 20 mm and a thickness of 2 mm using a press molding machine. PVA (polyvinyl alcohol) aqueous solution was used as an organic binder.

Next, this granulated powder was molded into pellets having a diameter of 20 mm and a thickness of 2 mm using a molding machine.

Next, the pellets were fired in the air at a temperature of 830 to 1050 ° C for 1 to 24 hours to obtain a disc-shaped dielectric ceramic composition sintered body.

Next, a predetermined amount of organic binder, a dispersant, and an organic solvent are added and kneaded to graphite powder on both surfaces of the sintered body of the dielectric ceramic composition obtained by the above, and the conductive paste having a suitable viscosity is printed in a predetermined pattern and fired in nitrogen gas. And a terminal electrode was formed. As a result, a single-layer magnetic capacitor was obtained.

The electrical characteristics of the magnetic capacitor thus obtained were measured. The measurement results are shown in Table 3 and Table 4.

Sample Number division Relative permittivity ε Quality factor Q Insulation Resistance IR (Ω) Temperature characteristic TC (ppm / ℃) Density р (g / cm 3) Example Comparative example One ○ 16 165 1.6 × 10 ¹² 43 3.5 2 ○ 64 43 1.8 × 10 ¹² 650 3.6 3 ○ 34 1450 2.1 × 10 ¹¹ 134 5.2 4 ○ 19 110 2.1 × 10 ¹¹ 286 4.9 5 ○ 22 126 1.9 × 10 ¹¹ 510 3.4 6 ○ 38 1440 2.1 × 10 ¹² 56 5.4 7 ○ 29 1370 1.6 × 10 ¹¹ 85 5.1 8 ○ 46 1410 1.5 × 10 ¹² 170 5.2 9 ○ 38 1260 7.6 × 10 ⁹ 94 5.5 10 ○ 39 1510 9.9 × 10 ¹⁰ 81 5.1 11 ○ 39 1420 3.6 × 10 ¹¹ 95 4.9 12 ○ 27 260 1.2 × 10 ¹¹ 64 3.3 13 ○ 22 140 1.7 × 10 ¹⁰ 73 3.8 14 ○ 39 1320 2.5 × 10 ¹¹ 81 5.3 15 ○ 41 1550 2.8 × 10 ¹² 66 5.2 16 ○ 35 580 2.9 × 10 ¹¹ 54 4.4

Sample Number division Relative permittivity ε Quality factor Q Insulation Resistance IR (Ω) Temperature characteristic TC (ppm / ℃) Density р (g / cm 3) Example Comparative example 17 ○ 39 100 2.3 × 10 ⁸ 186 5.6 18 ○ 26 260 1.4 × 10 ¹¹ 75 3.7 19 ○ 23 120 1.2 × 10 ¹¹ 62 3.9 20 ○ 41 200 2.4 × 10 ⁷ 389 5.1 21 ○ 39 270 2.7 × 10 ⁷ 301 5.1 22 ○ 29 280 1.6 × 10 ¹¹ 56 3.8 23 ○ 21 210 1.6 × 10 ¹¹ 49 3.3 24 ○ 41 1630 1.8 × 10 ¹² 79 5.3 25 ○ 39 136 1.1 × 10 ⁹ 286 5.2 26 ○ 41 140 1.2 × 10 ⁹ 360 5.4 27 ○ 39 1430 1.3 × 10 ¹² 89 5.1 28 ○ 37 1340 1.4 × 10 ¹² 75 5.5 29 ○ 36 160 1.3 × 10 ¹¹ 69 3.2 30 ○ 17 176 1.6 × 10 ¹¹ 49 3.1 31 ○ 46 1480 1.4 × 10 ¹² 170 5.1 32 ○ 38 1320 7.5 × 10 ⁹ 95 5.4

Here, the relative dielectric constant? Was measured under the conditions of 1 MHz and 1 Vrms at 25 ° C.

The quality factor (Q) was measured under the conditions of 1 MHz and 25 ° C.

The temperature characteristic TC measured the capacitance C1 at 25 degreeC, and the capacitance C2 at 125 degreeC, respectively, and substituted these measurement value into the following formula, and computed the temperature characteristic Tc.

Tc (ppmm / ℃)

= ((C2-C1) × 10 ⁶ ) / (C1 × 125-25))

The specific resistance (R (Ωcm)) measured the current value 1 minute after applying a DC voltage of 1000V at 25 ° C, and calculated the specific resistance from these voltage values and the current value.

As shown in Tables 3 to 4, Sample Nos. 1 and 2 have low density of sintered body, low relative dielectric constant, and large relative dielectric constant because of insufficient amounts of BaO and TiO ₂ as main components.

Sample numbers 4 and 5 have a low relative dielectric constant, a large dielectric constant of the relative dielectric constant, and a low density of the sintered compact due to an inadequate amount of Sm ₂ O ₃ of the main component.

Sample number 12 is difficult to sinter at low temperature because the amount of Al ₂ O _{3 that} is the second additive is increased, so that the density of the sintered compact is reduced.

Sample No. 13 had too low a sintering temperature to obtain a sufficient sintering density.

Sample number 17 has a low Q value and insulation resistance because the amount of glass component added is too large, and the temperature coefficient of the dielectric constant is large.

Since the sample number 18 has little addition amount of the glass component, low-temperature sintering property is not improved, the density of the sintered compact is low and the dielectric constant is also low.

Sample number 19 had a low Q value because the addition amount of CuO, which was a negative portion, was low, and low-temperature sintering was not improved, resulting in a low density of the sintered compact.

On the contrary, since sample No. 20 had a large amount of addition of CuO as a minor component, the insulation resistance was low and the temperature coefficient of the specific user ratio was large.

Since the sample numbers 21 and 22 are inadequate in the amount of ZnO added as a minor component, the insulation resistance decreases, the temperature coefficient of the dielectric constant increases, the low-temperature sintering property deteriorates, the density decreases, and the dielectric constant also decreases.

Sample No. 23 has a too high proportion of cast iron TiO ₂ , which deteriorates low-temperature sintering, resulting in lower density of the sintered body and lower dielectric constant.

Since the sample numbers 25 and 26 are inadequate in the amount of PbO or ZnO added as the second additive component, the Q value is lowered and the temperature coefficient TC of the dielectric constant is increased.

Sample No. 29 and No. 30 have an inadequate addition amount of the rare earth element compound as the first additive, resulting in deterioration of low temperature sintering properties, low density, and low relative dielectric constant and Q value.

As described above, it is apparent that the magnetic capacitor of the comparative example is inferior to the magnetic capacitor of the present invention in any of the relative dielectric constant?, The quality factor Q, and the temperature characteristic TC.

On the contrary, as is clear from Tables 3 and 4, the magnetic capacitor of the present invention has a high dielectric constant (ε), a quality factor (Q) and an insulation resistance even in the high frequency region, and has a low dielectric constant (TC). Moreover, nothing proved to be stable.

In addition, a high-density sintered body of sufficient density can be obtained even at low temperature sintering at 850 to 900 ° C, and a good value that satisfies the electrical characteristics can be obtained. As a result of observing the surface state of the magnetic capacitor of the present invention by using a metal microscope, it was confirmed that no pores or the like was found at the grain boundary and it became a compact sintered body.

As described above, according to the magnetic capacitor of the present invention, it is possible to realize a high dielectric constant and a high quality coefficient even in the high frequency region, and to exhibit good characteristics with a small coefficient of dielectric constant. In addition, the characteristics are stable in the high frequency region such as microwaves, and the reliability of the device is shaped in the high frequency region.

In addition, since it can be fired at a low temperature of 855 ~ 1050 ℃, it is possible to use an inexpensive non-metal or carbon-based material as the internal electrode, it is possible to lower the manufacturing course without lowering the characteristics.

Furthermore, since low-temperature firing is possible, the energy cost and firing time required for firing can be greatly reduced, thereby providing an inexpensive device.

Claims (19)

CuO is used as a minor component in a casting formed of xBaO-ySm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75). A dielectric ceramic composition comprising 8% by weight, 0.01-5% by weight of ZnO and 0.1-10% by weight of a glass composition. According to claim 1, 0.005 to 2.5% by weight of at least one rare earth element oxide selected from Y ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , Yb ₂ O ₃ or Ce ₂ O _{3 based} on the cast product Dielectric self-composition comprising the addition. The dielectric magnetic composition according to claim 1, wherein at least one of PbO or Bi ₂ O ₃ is added in an amount of 3% by weight or more based on the dielectric magnetic composition. 3. The dielectric magnetic composition according to claim 2, wherein at least one of PbO or Bi ₂ O ₃ is added in an amount of 3% by weight or more based on the dielectric magnetic composition. The dielectric ceramic composition according to claim 1, wherein 0.002 to 2 parts by weight of Al ₂ O ₃ is added to 100 parts by weight of the dielectric ceramic composition. The dielectric ceramic composition according to claim 2, wherein the dielectric magnetic composition is added by 0.005 to 2 parts by weight of Al ₂ O _{3 based} on 100 parts by weight of the dielectric magnetic composition. 4. The dielectric magnetic composition of claim 3, wherein 0.002 to 2 parts by weight of Al ₂ O ₃ is added to 100 parts by weight of the dielectric magnetic composition. 5. The dielectric ceramic composition according to claim 4, wherein 0.005 to 2 parts by weight of Al ₂ O ₃ is added to 100 parts by weight of the dielectric ceramic composition. The dielectric ceramic composition according to any one of claims 1 to 8, wherein the glass composition is formed of ZnO-SiO ₂ -based glass or Li ₂ O-Al ₂ O ₃ -SiO ₂ -based glass. The magnetic capacitor which forms an electrode in the both surfaces of the dielectric ceramic composition sintered compact of any one of Claims 1-8. The magnetic capacitor of claim 10, wherein the electrode is made of a nonmetal or a carbon-based material. A magnetic capacitor comprising alternately stacking an electrode and a sheet-like sintered body made of the dielectric magnetic composition according to any one of claims 1 to 8. The magnetic capacitor of claim 12, wherein the electrode is made of a nonmetal or a carbon-based material. A magnetic capacitor formed by forming electrodes on both surfaces of a dielectric ceramic composition sintered body according to claim 9. 9. A magnetic capacitor comprising alternately stacking an electrode and a sheet-like sintered body of a dielectric magnetic composition as described in claim 9. The magnetic capacitor of claim 14 or 15, wherein the electrode is made of a nonmetal or a carbon-based material. CuO as a minor component in a casting formed of xBaO-y Sm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75) To 8% by weight, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of the glass composition, if necessary, 0.005 to 2.5% by weight of Y ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , At least one rare earth element oxide selected from Yb ₂ O ₃ or Ce ₂ O ₃ , or powder to which 0.005 to 2 parts by weight of Al ₂ O ₃ is added is press-molded to form a bulk or sheet-shaped molded product. Method for producing a dielectric ceramic composition, characterized in that the firing at a temperature of ~ 1050 ℃. CuO as a minor component in a casting formed of xBaO-y Sm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75) To 8% by weight, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of the glass composition, if necessary, 0.005 to 2.5% by weight of Y ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , At least one rare earth element oxide selected from Yb ₂ O ₃ or Ce ₂ O ₃ , or powder to which 0.005 to 2 parts by weight of Al ₂ O ₃ is added is press-molded into a bulk phase, followed by one main component of the bulk molded article. An electrode is formed in a surface, and this molded object is baked at the temperature of 850-1050 degreeC, The manufacturing method of the magnetic capacitor characterized by the above-mentioned. CuO as a minor component in a casting formed of xBaO-y Sm ₂ O ₃ -zTiO ₂ (where x + y + z = 1, 0.05 ≦ x ≦ 0.30, 0.05 ≦ y ≦ 0.20, 0.65 ≦ z ≦ 0.75) To 8% by weight, 0.01 to 5% by weight of ZnO and 0.1 to 10% by weight of the glass composition, if necessary, 0.005 to 2.5% by weight of Y ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , At least one rare earth element oxide selected from Yb ₂ O ₃ or Ce ₂ O ₃ , or powder to which 0.005 to 2 parts by weight of Al ₂ O ₃ is added is press-molded into a sheet, followed by one main component of the sheet-like molded article. An electrode is formed on a surface, and this molded object is laminated | stacked and pressed in multiple thickness direction, and it is set as a laminated body, and this laminated body is baked at the temperature of 850-1050 degreeC, The manufacturing method of the magnetic capacitor characterized by the above-mentioned.