KR890004286B1 - High dielectric constant type ceramic composition - Google Patents

Abstract

The high dielectric constant magnetic composition for a ceramic capacitor has the formula XPb (Zn1/3 Nb2/3) O3-YPb (Mg1/3 Nb2/3) O3- ZPbTiO3 in which x,y,z have the values defined within lines connecting the following points a(x=0.50, y=0.00, z=0.50), b(z=1,00, y=0.00, z=0,00), c(x=0.20, y=0.80, z=0.00), d(x=0.05, y=0.90, z=0.05) of a ternary composition having apexes of respective component. and Pb is substituted by Ba, Sr or mixtures with 1-35 mole%.

Description

High dielectric constant magnetic composition

1 is a composition diagram showing the composition range of the present invention.

2 and 3 are diagrams showing the change in characteristics due to the amount of methyl (Me).

4 and 5 are curve diagrams showing temperature characteristics of permittivity.

6 and 7 are curve diagrams showing characteristics of a direct current bias electric field of permittivity.

8 is a curve diagram showing the temperature characteristics of CR.

9 is a curve diagram showing the characteristics of electrical distortion.

10 to 13 are X-ray diffraction patterns.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high dielectric constant magnetic composition with a small change in dielectric constant temperature coefficient (T.C.C.) temperature mainly involving Pb (Znl / 3 Nb2 / 3).

Examples of the electrical properties required as the dielectric material include dielectric constant dielectric constant temperature coefficient, dielectric loss, dielectric bias electric field dependence, capacitance resistance, and the like.

In particular, the capacitance resistance (CR value) needs to be high enough, and is specified in E1AJ (Japan Electromechanical Industry Association) 's electronic laminated multilayer capacitor (chip type) standard RC-3698B of 500 MΩ.μF or more at room temperature. It is.

It is also required to maintain high CR values even at high temperatures (eg CR values at 125 ° C are defined in DOD MILC -55681 B) for use in more severe conditions.

In addition, the dielectric constant temperature coefficient should be small. In general, a material having a high dielectric constant (K) tends to have a large T.C.C and a large K / T.C.C.

In the case of an element of a laminated type, since the electrode layer and the dielectric layer are fired integrally, it is necessary to use a material that is safe even at the firing temperature of the dielectric material.

Therefore, when the firing temperature of the dielectric material is high, expensive materials such as platinum (pt) and palladium (pd) must be used, so that the material can be baked at a low temperature of about 1100 ° C. or less so that a cheap material such as silver (Ag) can be used. Is required.

Background Art Conventionally known high dielectric constant magnetic compositions are those in which solid solution of tartarate zirconate or titanate is employed based on bar titanate.

Obviously, a higher permittivity can be obtained, but when the permittivity increases, T.C.C. becomes larger, and the bias field dependency becomes larger.

In addition, the firing temperature of the barium titanate-based material is a high temperature of about 1300-1400 ° C, and as an electrode material, an expensive material that can withstand high temperatures such as platinum and palladium is inevitably used, causing a high cost.

In order to solve the problem of this barium titanate system, various compositions have been studied. For example, iron niobate mainly (Japanese Patent Laid-Open No. 55-57204), magnesium niobate mainly (Japanese Laid Open 55-51758), magnesium tungsten acid mainly (Japanese Laid Open 52- 21662).

Mainly composed of lead iron niobate has a problem that the CR value is largely changed by the firing temperature, and in particular, the CR value at a high temperature is largely lowered.

Magnesium and niobate were mainly used as the firing temperature was relatively high, and magnesium tungsten was mainly used as the dielectric constant was small when the CR value was large, CR value was small when the dielectric constant was large.

Also, the T.C.C. of these materials is better than barium titanate, but not enough.

In addition, a solid solution of magnesium niobate and lead titanate has been studied for a material in which part of the lead is changed to barium, strontium, and calcium (Japanese Patent Laid-Open No. 55-121959). However, the TCC of this material is -25 to 85 ° C. Even good ones are -59.8%, which is not enough.

In addition, the CR value which is most important as a capacitor material is not mentioned, and its usefulness as a capacitor material is not clear.

In addition, Japanese Laid-Open Patent Publication No. 57-25607 discusses a material that is a solid solution of magnesium niobate and zinc niobate.

However, no mention is made of CR values and T.C.C and their usefulness as a capacitor material is not clear.

In addition, a solid solution of zinc niobate and nickel niobate has been studied for a material in which a part of the lead is replaced with barium, strontium, and calcium (Japanese Patent Laid-Open No. 58-214201).

However, the temperature coefficient of dielectric constant of this material is -25 ~ 85, which is -33%, which is the best one.

Also no value is mentioned and its usefulness as a capacitor material is not clear.

The present invention has been made in consideration of the above-described object, and an object thereof is to provide a high dielectric constant magnetic composition having a high dielectric constant and a low temperature coefficient.

The present invention is a general formula

x Pb (Zn1 / 3 Nb2 / 3) O _3-

y Pb (Mg 1/3 Nb 2/3) O ₃ -z PbTiO ₃

When expressed as

a (x = 0.50, y = 0.00, z = 0.50)

b (x = 1.00, y = 0.00, z = 0.00)

c (x = 0.20, y = 0.80, z = 0.00)

d (x = 0.05, y = 0.90, z = 0.05)

It is a high dielectric constant magnetic composition which substituted a part of composition Pb in the line which connects each point shown by at least 1 sort (s) among 1-35 mol% Ba and Sr.

Conventionally, it is a magnetic composition as a dielectric material.

Conventionally, various types of gray titaniumite-type magnetic materials have been studied as dielectric materials. Since zinc niobate (Pb (Zn1 / 3 Nb2 / 3) O ₃ ) is hardly magnetic, it is difficult to have a gray titanium structure. It was not suitable. (See pages 15–21 of NEC Research and Development Paper 29, April 1973).

According to the research of the present inventors, it has been found that magnetically stable gray titaniumite structure can be formed by appropriately substituting Pb of Pb (Zn 1/3 Nb 2/3) O ₃ with Ba or Sr.

It was also found that such magnetic compositions exhibit very high dielectric constant and insulation resistance, and also have very good temperature characteristics.

It was also found that the mechanical strength was also excellent.

As a result of further research, it has been found that by combining magnesium niobate and lead titanate with zinc zinc niobate, a high dielectric constant magnetic composition having higher dielectric constant and insulation resistance can be obtained.

Now, the composition range of the present invention composition will be described.

Me = Ba, Sr is an element necessary to form the legendary gray titaniumite structure, and when 1 mol% or less is mixed with pyrochlore structure, it does not show high dielectric constant and high insulation resistance. At 35 mol% or more, the dielectric constant decreases below about 1000 or the firing temperature rises above 1100 ° C.

Therefore, the substitution amount with the Me component is 0.01 <α <0.35 when expressed as (Pb _1-α Meα).

In dielectric materials, the Curie temperature should be close to room temperature (0 to 30 ° C) in order to increase the capacity at room temperature.

As described above, the Me component of the present invention is an essential component for forming a gray titaniumite structure, but also has a function of a shifter for lowering the Curie temperature of the inventive magnetic composition.

It also significantly increases the insulation resistance, which also improves mechanical strength.

The substitution amount of Pb by the Me component can be appropriately set in consideration of the Curie temperature and the like. In the region having high zinc niobate and lead titanate (X> 0.5, Z> 0.1), 10 mol% or more is preferable, and magnesium niobate has a high concentration. At (y> 0.6, Z <0.05), the substitution effect is sufficiently exhibited to 1 mol% or more.

1 shows the composition range of the inventive magnetic composition.

On the outside of the line segment ad, the firing temperature becomes higher than 1100 ° C and the insulation resistance decreases, so that a high CR value cannot be obtained.

In addition, since the Curie temperature is similar to the original room temperature on the outer side of the line segment Cd, the Curie point moves to the low temperature significantly by substitution by the Me component, and the dielectric constant at room temperature is greatly reduced.

Further, when d ₁ (x = 0.10, y = 0.80, z = 0.10), the inside of the line segment cd ₁ is more preferable.

Moreover, although magnesium niobate is exhibited by the addition of a small amount, it is preferable to contain 1 mol% or more practically. In consideration of the CR value, it is preferable that zinc contains 15 mol% or more of niobate lead, and even more preferably 20 mol% or more.

When it is 20 mol% or more, the dielectric loss is particularly small.

Also

c ₁ (x = 0.40, y = 0.60, z = 0.00)

d ₂ (x = 0.15, y = 0.70, z = 0.15)

d ₃ (x = 0.20, y = 0.60, z = 0.20)

c ₂ (x = 0.45, y = 0.55, z = 0.00)

When

Outside of line c ₁ d ₁ it is relatively difficult to obtain a dense magnetism.

Thus, considering CR value TCC, sintering property, etc., the inside of line segment c ₁ d ₂ especially the line segment c ₂ d ₂ and also the inside of line segment c ₂ d ₃ are preferable.

However, when the dielectric constant is considered, the compositional boundary divided into such line segments has sufficient characteristics.

FIG. 2 shows the composition of Me (= Ba or Sr) in the composition system (Pb _1-α Meα) (Zn 1/3 Nb 2/3) PO ₃ containing no magnesium titanium and 100% zinc niobate (point b in FIG. ₁ ). It is a graph (temperature 25 degreeC) which shows the change of capacitance-resistant CR and dielectric constant K by quantity (alpha).

If α = 0.1 or less, the fatigue chloro structure is combined, and thus high dielectric constant and high insulation resistance are not shown.

At α = 0.35 or more, the dielectric constant decreases to about 1000 and the firing temperature increases to 1100 ° C or more.

Therefore, 0.1 <α <0.35 is set.

As apparent from FIG. 2, when 0.1 < alpha < 0.35, that is, a part of Pb of the above-mentioned formula is replaced by at least one of 10 to 35 mol% of Ba and Sr, excellent characteristics can be achieved.

In particular, it can be seen that at 0.16 < alpha < 0.30, a high reliability of a CR value of 3000 MΩ mu F or more can be obtained.

In dielectric materials, the Curie temperature should be close to room temperature in order to increase the dielectric constant.

If Mg is not included, that is, y = 0, the Me component in the composition system of the present invention lowers the Curie temperature, while Ti increases the Curie temperature, and the addition of Ti increases the dielectric constant along with the Me component. Is effective.

However, if the Ti component is too large, the insulation resistance decreases and the CR value decreases. Therefore, the Ti amount Z is Z <0.5.

In addition, when Z is 0.5 or more, the firing temperature also becomes high at 1100 ° C.

In particular, in consideration of the effect of Pb (Zn 1/3 Nb 2/3) O _{3 as} a basic component, Z <0.4 is preferable. Even in the system containing no Mg and Ti (y = 0, z = 0), a sufficiently high dielectric constant magnetic composition is formed. When Ti is contained, the added effect is remarkable at Z> 0.05. .

3 shows the amount of Me in the composition system 50 mol% of zinc niobate and 50 mol% of magnesium niobate, namely (Pb _1-α Meα) {(Zn 1/3 Nb 2/3) 0.5 (Mg 1/3 Nb 2/3) 0.5] O ₃ It shows the change of CR value and permittivity by the amount α of Me (= Ba, Sr) in the composition of.

As is clear from this figure, the addition of a small amount (α = 0.01 to 0.35) of Me component, i.e., a large improvement in characteristics by replacing a part of Pb of the above-mentioned composition with at least one of 1 to 35 mol% of Ba and Sr It can be seen that.

In particular, the effect on the CR value is remarkable, and the reliability as a ceramic capacitor is excellent.

Although the present invention is mainly based on the above-described general formula, the stoichiometric ratio may be somewhat different.

When this composition is converted into oxide, it is as follows.

PbO 46.13-69.09 wt%

BaO 0.00 ~ 18.20 wt%

SrO 0.00 ~ 12.99 wt%

ZnO 0.42 ~ 9,13 wt%

Nb ₂ O ₅ 14.11-29.83 wt%

TiO ₂ 0.00 ~ 14.31 wt%

MgO 0.04-3.73 wt%

(However, the sum of BaO and SrO is 0.32 to 18.10 wt%).

Moreover, you may contain an impurity, an additive, a substituent, etc. within the range which does not impair the effect of this invention.

For example, a _{MnO, CoO, NiO, Sb 2} O 3, ZrO 2, La 2 O 3 solid transition metal group such as and the like.

The content of these additives is about 1 wt% at most.

In the present invention, it is effective to contain at least one of manganese oxide (MnO) and cobalt oxide (CoO) with respect to the above-mentioned composition.

Even a composition without such an additive exhibits sufficiently excellent characteristics, but by containing manganese oxide and cobalt oxide, remarkable effects such as improvement of internal pressure, improvement of T.C.C. and reduction of dielectric loss can be obtained.

In addition, the improvement of the aging time characteristic of dielectric constant is also shown.

This effect is caused by the addition of a small amount, but becomes remarkable when the addition content is 0.01 wt% or more.

However, the addition of a large amount is less than 0.5wt% because the decrease in insulation resistance and dielectric constant is large.

Next, the manufacturing method of the composition of the present invention will be described.

Pb, Ba, Sr, Zn, Nb, Ti, Mg oxides, carbohydrates, salts such as carbonates, oxalates which are oxides by firing, hydroxides, organic compounds, etc. Calcined later.

This calcination is carried out at about 700 ~ 850 ℃.

If the calcination temperature is too low, the sintered density is lowered. If the calcination temperature is too high, the sintered density is also lowered and the insulation resistance is lowered.

Next, the calcined product is ground to prepare a raw powder.

The average particle diameter is preferably about 0.8 ~ 2㎛, excessively large if the pores in the sintered body increases, if small, the molding decreases.

A high dielectric constant ceramic is obtained by molding into a desired shape using such a raw material powder and firing it.

By using the composition of the present invention, firing can be performed at a relatively low temperature of about 1100 ° C or less and about 980 to 1080 ° C.

In the case of manufacturing a device having a laminated type, a binder, a solvent, and the like are added to the above-described raw powder to slurry to form a green sheet, and the green sheet is formed on the inside of the green sheet. After printing an electrode, it manufactures by carrying out lamination | stacking, crimping | compression, and baking a predetermined | prescribed longevity.

At this time, since the dielectric material of the present invention can be sintered at a low temperature, a cheap material of Ag main body can be used as the internal electrode material.

In addition, since it can be baked at a low temperature in this manner, it is also effective as a paste material of a thick film dielectric printed on a circuit board or baked.

Such a magnetic composition of the present invention has a high dielectric constant and a good T.C.C.

10000와 같이 큰 유전율인 경우 특히 현저하다.In addition, since the CR value is large and has a sufficient value especially at a high temperature, it is excellent in reliability at a high temperature. The small TCC is a big feature of the invention, which is K

This is especially noticeable for large dielectric constants such as 10000.

When the permittivity is large in this manner, (dielectric constant) / (absolute value of the temperature change rate) must be large.

The present invention is very excellent in terms of advantages as well.

In addition, the dielectric constant bias electric field dependency is also superior to that of a conventional barium titanate-based material, and a material of about 10% or less can be obtained even at a rate of change of dielectric constant of 4 KV / mm.

Therefore, it is effective as a material for high pressure.

In addition, the dielectric loss is small and effective for alternating current and high frequency.

In addition, as described above, since the T.C.C. is small, a device having a small temperature change in the displacement amount can be obtained even when it is applied to an electric distortion type device.

Moreover, since the grain size at the time of baking is uniformized to 13 micrometers, it is also excellent in pressure resistance.

The electrical properties have been described so far, and the mechanical strength is also excellent enough.

As described so far, according to the present invention, a high dielectric constant magnetic composition having a high dielectric constant and excellent temperature and bias characteristics can be obtained.

In particular, since the magnetism excellent in such various characteristics can be obtained by low-temperature firing, it is also suitable for application to a multilayer type ceramic element such as a multilayer ceramic capacitor and a multilayer ceramic displacement generating element.

The present invention will now be described with reference to specific examples.

As a starting material, starting materials of oxides and carbonates of Pb, Ba, Sr, Zn, Nb, Ti, Mg, Mn, and Co are selected from the examples of Tables 1-4 according to examples. The mixture is then calcined at 700 to 850 ° C.

Subsequently, the calcined body was pulverized with a bowl mill or the like, dried, a binder was added, and particles were formed and pressed to form a disc-shaped body having a diameter of 17 mm and a thickness of about 2 mm.

Since the mixing and pulverizing bowl prevents the incorporation of impurities, it is preferable to use a bowl having high hardness and high toughness such as partially stabilized zircon oxide bowl.

The body was sintered for 2 hours at 980 to 1080 DEG C in air, and silver electrodes were attached to both main surfaces to measure respective characteristics.

Dielectric loss and capacity are measured by a digital LCR meter at 1KHz and 1Vrms 25 ℃, and the dielectric constant was calculated from this value.

Moreover, insulation resistance was computed from the value measured using the insulation resistance meter after applying the voltage of 100V for 2 minutes.

In addition, T.C.C. was represented by the change rate in -25 degreeC and 85 degreeC on the basis of the value of 25 degreeC.

Capacity resistivity was calculated | required from (dielectric constant) x (insulation resistance) x (dielectric constant of vacuum) in 25 degreeC and 125 degreeC.

The insulation resistance was measured in silicone oil to eliminate the effects of moisture in the air.

The result was shown to Tables 1-4.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

In Table 1, y = 0, that is, Composition Examples 1-28, which are above line segment ab in FIG. 1, 31-58 in Compositions within the scope of the present invention in Table 2, and Manganese Oxide or Coral Cobalt in Table 3; In Examples 61-65 and 4th table which added at least one of them, the reference examples 1-11 were shown as a composition example outside the range of this invention for comparison.

In addition, since y value and MgO value are both 0, 1st table | surface is abbreviate | omitted.

As is clear from Tables 1 to 3, the inventive magnetic composition has a high dielectric constant (K = 1400 or more) and good temperature characteristics (within -54% at -25 to 85C).

The CR value is also greater than 1100 MΩ · μF (25 ℃), and especially at 125 ℃, it is more than 260MΩ · μF, which is excellent in high temperature reliability.

5000과 같이 큰 유전율일 경우 특히 현저하다.Also K that TCC is small

This is especially noticeable for large dielectric constants such as 5000.

If the dielectric constant is large like this, (dielectric constant) / (absolute value of temperature change rate) should be large.

5000일때 값이 200이상으로 대단히 우수하다.In the example of the present invention, K

When the value is 5000, the value is over 200, which is very good.

The dielectric bias field dependence is also excellent within 15% at 1KV / mm.

In addition, the dielectric loss is less than 2.4% at 25 ℃, 1KHz.

In the composition containing 15 mol% or more of zinc niobate, the CR value is 2000 MΩ.mu.F or more, and 20 mol% or more.

In addition, the dielectric loss is also very small value of less than 2% above 20mol%.

Reference examples shown in Table 4 are outside the scope of the present invention composition.

It does not contain the Me component (Reference Examples 1 to 7) The dielectric constant is small, the CR value is extremely small, the dielectric loss is large, and the T.C.C.

In addition, Reference Examples 8 and 9 are in which Me component is added in an excessive amount, and the dielectric constant is small and the temperature change is also very large.

4 and 5 show the temperature characteristics of the dielectric constant.

FIG. 4 shows an example of the same composition as the first table without Mg and a reference example corresponding thereto. FIG. 5 compares the example shown in the second table with Mg and a reference example corresponding thereto. It is shown.

In Fig. First, the fourth, in order to compare _{(BaTiO 3) 89 - (CaTiO} 3) 10 - (MgZrO 3) are shown as the material properties of the barium titanate-based _one (Reference Example 12 not shown in the table). Reference Example 12 shows a large dielectric constant of about 6000 at 25 ° C, but a change rate of -50% or more at -25 ° C and 85 ° C.

On the other hand, in the present invention, even if K = 8500 (25 ℃) (Example 27) is within -32%, and at K = 3900 (25 ℃) (Example 16) is very small -9.5%.

In FIG. 5, the characteristics of the commercially available barium titanate material for multilayer capacitors are shown for comparison (Reference Examples 10 and 11).

Reference Example 10 shows a large dielectric constant of about 12000 at 25 ° C, but at least -80% of T.C.C. at -25 ° C and 85 ° C.

In contrast, in the present invention, even if K = 11000 (25 ° C), it is within -41% of only (Example 38), and is very small, within -20% of (Example 33) of K = 6500 (25 ° C).

In this TCC, the + side change is more important than the-side change with respect to the value at room temperature, and the material showing a change of + 30% or more does not satisfy any of the capacitors of EIA, EIAJ, and JIS. There is no

For example, 0.3 Pb Nil / 3 Nb2 / 3 O ₃ -0 using nickel niobate instead of magnesium niobate and lead titanate. 10 atom% of Pb is replaced with Ba in 7Pb Zn 1/3 Nb 2/3 O ₃ , and the rate of change at −25 ° C. is + 35%.

Reference examples 1, 2, 3, 6, 7, and 8 are also not practical at all as capacitor materials.

6 and 7 are graphs showing DC bias electric field dependence.

FIG. 6 compares the example shown in the 1st table which does not contain Mg, and the reference example corresponding to it, and FIG. 7 compares the example of 2nd table and the reference example corresponding to it.

In general, the dielectric constant tends to decrease as the bias electric field increases, and this condition becomes more pronounced as the dielectric constant increases.

In Fig. 6, Reference Example 12 exhibits a tendency of very large decrease in dielectric constant of about 6000 at -25% at 1KV / mm and -63% at 2KV / mm.

On the other hand, in Example 12, the dielectric constant is 6900, which is very small at -1% at 1KV / mm and only -28% at 2KV / mm.

In Fig. 7, Reference Example 10 shows a tendency of very large decrease in dielectric constant of about 12000 to -80% at 1KV / mm and -93% at 2KV / mm.

On the other hand, Example 8 is very small at -45% at 1KV / mm and only -64% at 2KV / mm, although the dielectric constant is about the same as 11000.

In addition, barium titanate (Reference Example 13 not shown in the table) has the same dielectric constant as Example 11, but shows a change of -50% at 3 KV / mm, which is very small at -10% in Example 11.

Similarly, barium titanate (Reference Example 11) shows the same dielectric constant as Example 54, but shows a change of -50% at 4 KV / mm, which is very small at -10% in Example 54.

Thus, the composition of the present invention having a small DC bias electric field dependency is effective as a high-pressure capacitor material.

In the case where the multilayer capacitor is considered, it is necessary to reduce the thickness per layer of the dielectric layer in consideration of the increase in capacity in the same shape, but the applied electric field per layer becomes high. However, since the composition of the present invention has excellent bias characteristics, the characteristics thereof do not decrease even when applied to such a device.

In the sample of Example 54, the dielectric loss was very small, 0.01%, which is suitable for alternating current.

8 shows the temperature characteristics of the CR value.

In the case of the present invention, the decrease in the CR value even at a high temperature is slight and shows a very high value of 4000 M? 占 F (125 占 폚) in Example 15 to 1600 M 占 占 F (125 占 폚) in Example 16, and the reliability is excellent.

On the other hand, Reference Example 12 shows a high value of about 4000 MΩ · F at room temperature, but it is extremely reduced to 100 MΩ · F at 125 ° C.

9 shows the electrical distortion of Example 38. FIG.

The electric distortion was detected using a XY recorder as the irrigation of the applied electric field of the sample by detecting the displacement of the longitudinal effect with a contact type displacement detection potentiometer.

The shape of the sample was a disk shape of 0.00 mm thickness and a diameter of 12.0 mm, and the silver paste was applied to both surfaces of the sample at 800 ° C. to form an electrode.

The relationship between the distortion and the electric field is a quadratic curve with little hysteresis, and shows a vertical effect electric distortion of 0.85 × 10 ⁻⁴ when an electric field of 10 KV / cm is applied.

As apparent from FIG. 9, it was found that the magnetic composition of the present invention can also be used as a material for a multilayer ceramic actuator.

FIG. 10 is an X-ray diffraction diagram of Example 15, which is almost a complete titaniumite phase.

Therefore, the dielectric constant is excellent at 6300, CR value of 6500 MΩ · F (25 ° C) and 4000 MΩ · F (125 ° C).

In contrast, in the case of Reference Example 6 without substitution by Ba of the Pb site, as shown in FIG.

Therefore, the dielectric constant is small at 990 and the CR value is also very small at 150 M? 占 F (25 占 폚), which is not practical at all.

FIG. 12 is an X-ray diffraction diagram of the composition of Example 38, which also has a nearly complete gray titaniumite shape.

Therefore, the dielectric constant is excellent at 11000 and CR value of 34000 M? 占 F (25 占 폚) 6000 M? 占 F (125 占 폚).

In contrast, in the case of Reference Example 3 without substitution by Ba of the Pb site, as shown in FIG.

Therefore, the dielectric constant is as small as 4500 and the CR value is also very small as 620 M? 占 F (25 占 폚), which is not practical at all.

The multilayer ceramic capacitor was then prepared using the composition of Example 12, the composition containing 0.25 mol% MnO and CoO in Example 12, the composition of Example 38 and the composition containing 0.1 mol% MnO and CoO in Example 38 It will be described with respect to the embodiment created.

First, a binder and an organic solvent were added to the roasted powder having such a composition and slurried, and a 30 µm green sheet was prepared using a doctor blade caster.

An electrode paste of 80 Ag / 20 Pd was printed on the green sheet in a predetermined pattern, and 20 sheets of sheets having such an electrode pattern were laminated and pressed.

Then, it cut | disconnected in the predetermined shape and degreased, and baked at 1020 degreeC and the conditions of 2 hours.

After sintering, Ag paste was applied as an external electrode to prepare a multilayer ceramic capacitor.

The electrical characteristics are shown in Tables 5 and 6.

Table 5 compares the electrical properties of the multilayer ceramic capacitor obtained by the composition of Example 12 and the composition obtained by adding MnO and CoO to Example 12. Table 6 shows MnO and CoO by adding the composition of Example 38 and The electrical properties were compared with the laminated composition capacitor obtained from the obtained composition.

[Table 5]

[Table 6]

It can be seen that the dielectric constant of the multilayer ceramic capacitor obtained from the composition obtained by adding MnO and CoO to Example 12 is about 6500 and each characteristic is sufficiently excellent as shown in Table 5.

In particular, the temperature characteristic is within ± 15% at -25 ~ 85 ℃, and satisfies the C characteristic of EIAJ and W5R characteristic of EIA.

In addition, in the composition of Example 12, a multilayer ceramic capacitor having satisfactory electrical properties can be obtained. From the composition obtained by adding MnO and CoO, it is clear that a multilayer ceramic capacitor having improved electrical properties can be obtained.

The dielectric constant of the multilayer ceramic capacitor obtained from the composition obtained by adding MnO and CoO to Example 38 is about 11000, and as shown in Table 6, it can be seen that each characteristic is sufficiently excellent.

In particular, the TCC is within ± 50% at -25 to 85 ° C and satisfies the E characteristics of JIS and the Z ₅ U characteristics of EIA.

In this case as well, it will be clear that by adding MnO and CoO, the electrical characteristics can be improved more than when not added.

As described above, the high dielectric constant ceramic composition according to the present invention is excellent in various characteristics such as T.C.C. and is particularly effective as a material for multilayer ceramic capacitors.

Claims (6)

Pb-based high dielectric constant in magnetic composition x Pb (Zn _1/3 Nb _2/3 ) O _3- y Pb (Mg _1/3 Nb _2/3 ) O ₃ -z Pb TiO ₃ of the ternary degree shown in FIG. a (x = 0.50, y = 0.00, z = 0.50) b (x = 1.00, y = 0.00, z = 0.00) c (x = 0.20, y = 0.80, z = 0.00) d (x = 0.05, y = 0.90, z = 0.05) is characterized in that a part of Pb of the composition in the hatched area connecting each point is replaced with at least one of 1-35 mol% of Ba and Sr. High dielectric constant magnetic composition. The high dielectric ceramic composition according to claim 1, further comprising 0.01-0.5 wt% of at least one of manganese oxide and cobalt oxide. The high dielectric constant magnetic composition as claimed in claim 1, wherein a part of Pb of the composition of the line segment connecting a and b of the ternary degree of FIG. 1 is replaced with at least one of 10-35 mol% of Ba and Sr. . The ceramic capacitor according to any one of claims 1 to 3, which is made using a high dielectric constant magnetic composition. The ceramic capacitor according to claim 4, wherein the ceramic capacitor is laminated. An electric distortion device made using the high dielectric constant magnetic composition of claim 1.

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