KR102089701B1 - Dielectric ceramic composition and multilayer ceramic capacitor comprising the same - Google Patents

Abstract

The invention includes a second main component represented by the first principal component and _{Bi 0 .5+ a Na 0 .5+ a} TiO 3 represented by _{BaTiO 3, (1-z)} BaTiO 3 _{- zBi 0 .5+ a Na 0 .5+} a TiO base powder (where z is the 0.05≤z≤0.5, wherein a is -0.025≤a≤0.025) represented by ₃ and comprises a, Bi content of 1.0 at When less than% and Na content less than 5.0 at%, the first grain, Bi content 1.0 ~ 70 at%, Na content 5.0 ~ 70 at% of the grain, the second grain, the second grain to the unit area It relates to a dielectric ceramic composition having an area ratio of 5.0 to 50%.

Description

Dielectric ceramic composition and multilayer ceramic capacitor including the same TECHNICAL FIELD

The present invention relates to a dielectric ceramic composition having guaranteed X9R temperature characteristics and reliability and a multilayer ceramic capacitor comprising the same.

In general, electronic components using ceramic materials such as capacitors, inductors, piezoelectric elements, varistors, or thermistors include ceramic bodies made of ceramic materials, internal electrodes formed inside the body, and external electrodes installed on the surface of the ceramic body to be connected to the internal electrodes. It is provided.

Among ceramic electronic components, a multilayer ceramic capacitor includes a plurality of stacked dielectric layers, internal electrodes disposed to face each other with a dielectric layer interposed therebetween, and external electrodes electrically connected to the internal electrodes.

The multilayer ceramic capacitor is widely used as a component of a mobile communication device such as a computer, a PDA, and a mobile phone due to its small size, high volume, and easy mounting.

Multilayer ceramic capacitors are usually produced by laminating internal electrode paste and dielectric layer paste by a sheet method or a printing method, and simultaneously firing.

Recently, the proportion of electronic control devices in automobiles is increasing, and the demand for multilayer ceramic capacitors usable at high temperatures of 150 degrees or more is increasing due to the development of hybrid vehicles and electric vehicles.

Currently, there is a C0G-based dielectric as a dielectric material that can be fired in a reducing atmosphere and applicable to a 200-degree warranty product, but there is a problem that it is difficult to manufacture a high-capacity product because the dielectric constant is very low, about 30.

In the case of BaTiO ₃ , the dielectric constant is higher than 1000, but it has a feature that the dielectric constant drops rapidly at a Curie temperature of 125 degrees or higher, so it is impossible to guarantee characteristics up to 200 degrees, which is an area of 150 degrees or higher.

Therefore, a material having a high Curie temperature and maintaining a relatively high dielectric constant to satisfy the X9R temperature characteristic and to guarantee reliability is required.

Korean Patent Publication No. 10-2012-0129918

It is an object of the present invention to provide a dielectric ceramic composition with guaranteed X9R temperature characteristics and reliability and a multilayer ceramic capacitor comprising the same.

The dielectric ceramic composition according to an embodiment of the present invention includes the second principal component represented by the first principal component and _{Bi 0 .5+ a Na 0 .5+ a} TiO 3 represented by BaTiO _3, (1-z) BaTiO _{3 - zBi 0 .5+ a Na 0 .5+} a TiO base powder (where z is the 0.05≤z≤0.5, wherein a is -0.025≤a≤0.025) represented by ₃ and comprises a, Bi content of 1.0 at When less than% and Na content less than 5.0 at%, the first grain, Bi content 1.0 ~ 70 at%, Na content 5.0 ~ 70 at% of the grain, the second grain, the second grain to the unit area The area ratio of is 5.0 to 50%.

A multilayer ceramic capacitor according to another embodiment of the present invention includes a ceramic body in which a dielectric layer and first and second internal electrodes are alternately stacked; And first and second external electrodes formed on both ends of the ceramic body and electrically connected to the first and second internal electrodes, wherein the dielectric layer has a Bi content of less than 1.0 at% and a Na content of 5.0. When the grain size less than at% is referred to as a first grain size, and when a grain size having a Bi content of 1.0 to 70 at% and a Na content of 5.0 to 70 at% is referred to as a second grain size, the area ratio of the second grain size to the unit area is 5.0 to 50%.

According to one embodiment of the present invention, a dielectric ceramic composition satisfying X9R temperature characteristics and having a high dielectric constant, a dielectric layer, and a multilayer ceramic capacitor including the same can be implemented.

In addition, by applying a sintering aid capable of firing at 1050 ° C. or less according to the temporary form of the present invention, the volatilization of Bi can be suppressed to achieve the target characteristics of the multilayer ceramic capacitor of the present invention.

1 and 2 are schematic diagrams and microstructures for positions P1, P2, P3, and P4 that analyze the content of Bi and Na by STEM / EDS analysis in a microstructure composed of first and second crystal grains and within each grain.
3 is a graph measuring the Bi and Na contents of P1 to P4 of the first crystal grain, and FIG. 4 is a graph measuring the Bi and Na contents of P1 to P4 of the second crystal grain.
5 is a schematic perspective view showing a multilayer ceramic capacitor according to an embodiment of the present invention.
6 is a schematic cross-sectional view showing a multilayer ceramic capacitor taken along VI-VI` of FIG. 5.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and elements indicated by the same reference numerals in the drawings are the same elements.

The present invention relates to a dielectric ceramic composition, and electronic components including the dielectric ceramic composition include capacitors, inductors, piezoelectric elements, varistors, or thermistors. Hereinafter, multilayer ceramic capacitors are examples of dielectric ceramic compositions and electronic components. Explain.

In accordance with one embodiment of the invention the dielectric ceramic composition has a first main component and _{Bi 0 .5+ a Na 0 .5+ a} TiO (1-z) BaTiO and a second principal component represented by the _three represented by BaTiO _{3 3} -The base material powder represented by zBi _{0.5 + a} Na _{0.5 + a} TiO ₃ (however, z satisfies 0.05≤z≤0.5 and a is -0.025≤a≤0.025).

The dielectric ceramic composition according to an embodiment of the present invention may satisfy X9R (-55 ° C to 200 ° C) characteristics specified in the EIA (Electronic Industries Association) standard.

More specifically, according to an embodiment of the present invention, copper (Cu) is used as an internal electrode, and a dielectric ceramic composition capable of firing in a reducing atmosphere in which the copper (Cu) is not oxidized is provided.

In addition, by providing a multilayer ceramic capacitor using the same, it is possible to realize the excellent reliability while satisfying the temperature characteristics.

Particularly, in the present invention, BaTiO ₃ having a high dielectric constant and (Bi _{0.5 + a} Na _{0.5 + a} ) TiO ₃ having _a high Curie temperature are used, and a dielectric ceramic composition capable of firing at 1050 degrees or less is used to suppress Bi volatility as much as possible. The target characteristics of the present invention could be realized by preparing a sample in the form of a composite composed of two types of crystal grains each having these compositions in a sintered body of and controlling the area ratio of these two grains.

Hereinafter, each component of the dielectric ceramic composition according to an embodiment of the present invention will be described in more detail.

a) base powder

In accordance with one embodiment of the invention the dielectric ceramic composition has a first main component and _{Bi 0 .5+ a Na 0 .5+ a} TiO (1-z) BaTiO and a second principal component represented by the _three represented by BaTiO _{3 3} -The base material powder represented by zBi _{0.5 + a} Na _{0.5 + a} TiO ₃ (however, z satisfies 0.05≤z≤0.5 and a is -0.025≤a≤0.025).

In the above equation, z may satisfy 0.05≤z≤0.5.

In addition, a may satisfy -0.025≤a≤0.025.

The first main component may be represented by BaTiO ₃ , and the BaTiO ₃ may be a ferroelectric material having a Curie temperature of about 125 degrees as a material used in a general dielectric base material.

The first main component is (Ba _{1 - x} Ca _x ) (Ti _{1 - y} Ca _y ) O ₃ (BCTZ), Ba (Ti _1- ) modified by partially dissolving Ca, Zr, etc. as well as the component represented by BaTiO _{3 y} Zr _y ) O ₃ (BTZ) or the like is also possible.

In addition, the second principal component can be expressed as _{Bi 0 .5+ a Na 0 .5+ a} TiO 3.

The a may satisfy -0.025≤a≤0.025, and preferably, the second main component may be represented by Bi _0.5 Na _0.5 O ₃ .

That is, the dielectric base material powder of a ceramic composition in accordance with one embodiment of the invention is a mixture of materials represented by the Curie temperature low BaTiO ₃ ferroelectric material and a _{Bi 0 .5+ a Na 0 .5+ a} TiO 3 as a percentage It can be in the form.

The dielectric layer and the multilayer ceramic capacitor using the dielectric ceramic composition according to one embodiment of the present invention have a high dielectric constant and are fired at 1050 ° C. or lower by mixing the first main component and the second main component material at a constant ratio as described above to produce a base material powder. This is possible, and in particular, can satisfy the X9R temperature characteristics.

Dielectric porcelain composition according to an embodiment of the present invention has a dielectric constant at room temperature of 1000 or more, a resistivity at room temperature of 1.0 × 10 ¹¹ Ohm-cm or more, a high temperature of 200 TCC (200 ° C) less than ± 22% and a high temperature (200 ° C) withstand voltage of 50 V / Simultaneous realization of all properties above µm is possible.

In addition, the base powder of the dielectric ceramic composition may be in the form of a solid solution in addition to a mixture of materials having different Curie temperatures. When the base powder is in the form of solid solution, the base powder may have a form having one or more phases. For example, a crystal grain having a Bi content of less than 1.0 at% and a Na content of less than 5.0 at% is referred to as a first grain, and a crystal grain having a Bi content of 1.0 to 70 at% and a Na content of 5.0 to 70 at% is referred to as a second grain, The base powder may have a shape having first and second crystal grains.

1 and 2 are schematic diagrams and microstructures for positions P1, P2, P3, and P4 that analyze the content of Bi and Na by STEM / EDS analysis within each crystal grain and the microstructure composed of the first grain and the second grain, 3 is a graph measuring the Bi and Na contents of P1 to P4 of the first crystal grain, and FIG. 4 is a graph measuring the Bi and Na contents of P1 to P4 of the second crystal grain.

1 and 2, the microstructure of the dielectric layer of the multilayer ceramic electronic component using the dielectric composition according to one embodiment of the present invention includes first crystal grains 10 and second crystal grains 20.

The first crystal grain 10 means a grain having a Bi content of less than 1.0 at% and a Na content of less than 5.0 at% by measuring the content of Bi and Na at positions P1 to P4 in one of the grains shown in FIGS. 1 and 2. That is, as shown in Figure 3, by measuring the Bi content and Na content of P1 to P4, the average of the four places Bi content of 1.0 at%, Na content of less than 5.0 at% can be defined as the first grain have.

The second crystal grains 20 measure the content of Bi and Na at the positions of P1 to P4 in one of the grains shown in FIGS. 1 and 2, thereby obtaining grains having a Bi content of 1.0 to 70 at% and a Na content of 5.0 to 70 at%. it means. That is, as shown in Figure 4, by measuring the Bi content and Na content of P1 to P4, the average of the four places Bi content of 1.0 ~ 70 at%, Na content of 5.0 ~ 70 at% grains as the first grain Can be defined.

In the dielectric ceramic composition according to an embodiment of the present invention, when the area ratio of the second crystal grain to the unit area is 5.0 to 50%, it is possible to simultaneously implement all of the above-described characteristics. That is, when the area ratio of the second crystal grain to the unit area is out of 5.0 to 50%, all the target characteristics of the present invention cannot be realized.

The base powder is not particularly limited, but the average particle diameter of the powder may be 300 nm or less.

b) first subcomponent

According to one embodiment of the present invention, the dielectric ceramic composition may further include an oxide carbonate containing Li as a first subcomponent, and may further include Li ₂ CO ₃ . The first subcomponent may be included from 0.2 mol to 5.0 mol with respect to 100 mol of the base powder.

The first subcomponent serves to improve room temperature resistivity and high temperature withstand voltage characteristics of the multilayer ceramic capacitor to which the dielectric ceramic composition is applied.

If the first sub-component is less than 0.2 mol with respect to 100 mol of the base material powder, the sintering density is low, resulting in a very low temperature resistivity and high-temperature withstand voltage. A problem that lowers to less than V / µm may occur.

Therefore, in the dielectric ceramic composition according to an embodiment of the present invention, when the content of the first subcomponent is 0.2 to 5.0 mol with respect to 100 mol of the base material powder, it is possible to simultaneously implement all the above-described properties.

c) second subcomponent

According to one embodiment of the present invention, the dielectric ceramic composition may further include an oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn as the second subcomponent, , Preferably it may further include MnO ₂ or V ₂ O ₅ .

As the second sub-component, oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu and Zn may be included in an amount of 0.2 mol to 3.0 mol with respect to 100 mol of the base powder have.

Alternatively, when two or more types of the second subcomponent are included, the total content of the second subcomponent based on at% may be included to satisfy 0.2 to 3.0 at%.

The second sub-component serves to improve the room temperature resistivity and high temperature withstand voltage characteristics of the multilayer ceramic capacitor to which the dielectric ceramic composition is applied.

If the total content of the second subcomponent is less than 0.2 at%, the room temperature specific resistance and high temperature withstand voltage characteristics may be deteriorated.

Even when the content of the second subcomponent exceeds 3.0 at%, the resistivity at room temperature and the high temperature withstand voltage may be deteriorated.

In particular, the dielectric ceramic composition according to an embodiment of the present invention may further include a second subcomponent having a content of 0.2 to 3.0 at% with respect to 100 at% of the base powder, thereby enabling low-temperature firing and high high temperature. Withstand voltage characteristics can be obtained, and simultaneous implementation of all of the above characteristics is possible.

d) third subcomponent

According to one embodiment of the present invention, the dielectric ceramic composition may include a third subcomponent comprising at least one selected from the group consisting of oxides and carbonates of at least one element of Ba and Ca, preferably BaCO ₃ It may further include ..

The third subcomponent may be included in an amount of 0.2 to 10.0 mol with respect to 100 mol of the base powder.

If the third sub-component is less than 0.2 mol with respect to 100 mol of the base material powder, a high temperature withstand voltage problem is very low. Can occur.

Therefore, in the dielectric ceramic composition according to an embodiment of the present invention, when the content of the third subcomponent is 0.2 to 10.0 mol with respect to 100 mol of the base material powder, it is possible to simultaneously implement all the above-described properties.

e) fourth accessory ingredient

According to one embodiment of the present invention, the dielectric ceramic composition may include a fourth sub-component including one or more selected from the group consisting of oxides of Si elements, carbonates of Si elements, and glasses containing Si elements, Preferably, SiO ₂ may be further included.

The fourth subcomponent may be included in 0.2 to 5.0 mol with respect to 100 mol of the base powder.

When the content of the fourth subcomponent is less than 0.5 mol with respect to 100 mol of the base powder, the sintering density is low, and the specific temperature resistance and the high temperature withstand voltage may be lowered. As a problem, the high temperature withstand voltage may be lowered.

5 is a schematic perspective view showing a multilayer ceramic capacitor 100 according to an embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view showing a multilayer ceramic capacitor 100 taken along VI-VI ′ in FIG. 5.

5 and 6, the multilayer ceramic capacitor 100 according to another embodiment of the present invention includes a ceramic body 110 in which the dielectric layers 111 and the first and second internal electrodes 121 and 122 are alternately stacked. ). At both ends of the ceramic body 110, first and second external electrodes 131 and 132 that are in communication with the first and second internal electrodes 121 and 122, which are alternately disposed inside the ceramic body 110, are respectively provided. Is formed.

Although the shape of the ceramic body 110 is not particularly limited, it may be generally a hexahedral shape. Further, the dimensions are not particularly limited, and can be appropriately sized depending on the application, and may be, for example, (0.6 to 5.6 mm) x (0.3 to 5.0 mm) x (0.3 to 1.9 mm).

The thickness of the dielectric layer 111 may be arbitrarily changed according to the capacitor's capacity design. In one embodiment of the present invention, the thickness of the dielectric layer after firing may be preferably 0.1 μm or more per layer.

The thickness of the dielectric layer may be 0.1 µm or more because a dielectric layer having a thickness that is too thin has a small number of crystal grains present in one layer, which adversely affects reliability.

The first and second internal electrodes 121 and 122 are stacked such that each cross section is alternately exposed on the surfaces of opposite ends of the ceramic body 110.

The first and second external electrodes 131 and 132 are formed at both ends of the ceramic body 110 and are electrically connected to exposed cross sections of the alternately disposed first and second internal electrodes 121 and 122. Construct a capacitor circuit.

First and second conductive material included in the internal electrodes 121 and 122 is not particularly limited, the dielectric layer according to an embodiment of the present invention has a first main component represented by BaTiO ₃ and Bi _{0 .5+ a} Na _{0 .5+ a} TiO (1-z) and a second principal component represented by BaTiO _{3 3} -Since the base material powder represented by zBi _{0.5 + a} Na _{0.5 + a} TiO ₃ (where z is 0.05≤z≤0.5 and a is -0.025≤a≤0.025) is used, the first magnetic material composition is used. And the second internal electrodes 121 and 122 may use copper (Cu).

The thicknesses of the first and second internal electrodes 121 and 122 may be appropriately determined according to the use and the like, and are not particularly limited, but may be, for example, 0.1 to 5 μm or 0.1 to 2.5 μm.

The conductive materials contained in the first and second external electrodes 131 and 132 are not particularly limited, but nickel (Ni), copper (Cu), or alloys thereof may be used.

The thickness of the first and second external electrodes 131 and 132 may be appropriately determined according to the use and the like, and is not particularly limited, but may be, for example, 10 to 50 μm.

  The dielectric layer 111 constituting the ceramic body 110 may include a dielectric magnetic composition according to an embodiment of the present invention.

The dielectric ceramic composition includes (1-z) BaTiO ₃ -zBi _{0.5 + a} Na _{0.5 + a} TiO comprising a first main component represented by BaTiO ₃ and a second main component represented by Bi _{0.5 + a} Na _{0.5 + a} TiO ₃ Base material powder represented by ₃ (however, z is 0.05≤z≤0.5, a includes -0.025≤a≤0.025).

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples, but this is for the purpose of helping the specific understanding of the present invention and the scope of the present invention is not limited by the Examples.

After mixing with a dispersant using ethanol and toluene as solvents in the compositions specified in Tables 1, 3, and 5 below, a binder was mixed to prepare a ceramic sheet.

An active sheet is produced by laminating 21 layers by printing copper (Cu) electrodes on a molded ceramic sheet, and the cover sheets located at the top and bottom of the active sheet are laminated with 25 layers of cover sheets (10 to 13 µm). Pressed to produce a press bar.

Thereafter, the compressed bar was cut into chips having a size of 3.2 mm × 1.6 mm using a cutter.

After the cut chip was calcined for debinding, calcination was performed at 1050 ° C. under a reducing atmosphere (N ₂ atmosphere), and an external electrode was formed on the calcined chip with Cu paste.

As the base material the main component was used as BaTiO ₃ and _{(Bi 0. 5 Na 0.} 5) TiO 3 powder with an average particle size of 300 nm.

The raw material powder containing the main component and the subcomponent was used as a mixing / dispersing media of zirconia balls, mixed with ethanol / toluene, a dispersing agent and a binder, and then ball milled for 20 hours.

The prepared slurry was formed into a molding sheet with a thickness of 3.5 µm and 10 to 13 µm using a doctor blade type coater.

 A copper (Cu) internal electrode was printed on the sheet having a thickness of about 10 μm.

The upper and lower cover layers were laminated in 25 layers with a molded sheet having a thickness of 10 to 13 µm, and 21 sheets of the internal electrode printed sheets having a thickness of about 2.0 µm were laminated to produce an active layer to produce a bar, and then laminated. The ceramic capacitor was completed.

For the finished prototype multilayer ceramic capacitor (Proto-type MLCC) specimen, the room temperature capacitance and dielectric loss were measured at 1 kHz and AC 0.2V / μm using an LCR meter.

The dielectric constant of the MLCC chip dielectric was calculated from the capacitance, the dielectric thickness of the MLCC chip, the internal electrode area, and the number of stacks.

The insulation resistance at room temperature was measured after taking 60 samples and applying DC 10V / μm after 60 seconds.

The change in capacitance with temperature was measured in a temperature range of -55 ° C to 125 ° C.

In the high-temperature IR boosting experiment, resistance deterioration behavior was measured while increasing the voltage step by 5V / μm at 150 ° C. The time of each step was 10 minutes and the resistance value was measured at 5 second intervals.

High-temperature withstand voltage was derived from the high-temperature IR boosting experiment, and when applying the voltage step dc 5V / μm per dielectric unit thickness at 150 ℃ for 10 minutes and measuring while continuously increasing this voltage step, the IR was 10 ⁵ Ω or more. It means the voltage that withstands.

The RC value is the product of the room temperature capacitance measured at AC 0.2V / μm and 1 kHz and the insulation resistance measured at DC 10V / μm.

Tables 2, 4, and 6 show the properties of a prototype multilayer ceramic capacitor (Proto-type MLCC) to which Cu internal electrodes corresponding to the compositions specified in Tables 1, 3, and 5 were applied.

Table 1 shows the first sub-component Li ₂ CO ₃ : 1.8 mol, the second sub-component MnO ₂ : 0.5 mol, V ₂ O _{5 as} compared to the base material (1-z) BaTiO ₃ + z (Bi _0.5 Na _0.5 ) TiO ₃ 100 mol: 0 mol, third subcomponent BaCO _3: 1.0 mol, fourth subcomponent SiO _2: 1.0 mol, the second principal component _{(.. Bi 0 5 Na 0} 5) TiO 3 depict an embodiment the composition according to the content of z values, and Table 2 The properties of the prototype multilayer ceramic capacitor (Proto-type MLCC) corresponding to these compositions are shown.

Referring to Table 2, when z is less than 0.05 (Examples 1 and 2), there is a problem that the high temperature TCC (200 ° C) deviates from ± 22%, and when z is greater than 0.5 (Example 8), room temperature specific resistance There is a problem that this is lowered to less than 1.0 × 10 ¹¹ Ohm-cm, and the high temperature withstand voltage is lowered to less than 50 V / µm. Therefore, when z satisfies 0.05 or more and 0.5 or less, the dielectric ceramic composition according to an embodiment of the present invention has a dielectric constant of 1000 or more, a specific resistivity of room temperature of 1.0 × 10 ¹¹ Ohm-cm or more, and a high temperature of 200 TCC (200 ° C). Simultaneous realization of all characteristics of less than ± 22% and high temperature (200 ℃) withstand voltage of 50 V / µm or more. In this case, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

Alternatively, the embodiment 9 is to represent a characteristic in a case made of a single main component _{(Ba 0. 9 Bi 0.} 1 Na 0. 1) TiO 3 solid solution, the content of each atom of the main component is similar to the embodiment 4 or 5, but The area ratio of the second crystal grain to the unit area corresponds to 100%, and in such a case, it can be seen that the target characteristic of the present invention is not implemented. Therefore, in order to realize the target characteristic of the present invention, the area ratio of the second crystal grain to the unit area should satisfy 5 to 50%.

Examples 10 to 18 in Table 3 is the base material 0.8BaTiO ₃ + 0.2 (Bi _0.5 Na _0.5 ) TiO ₃ Compared to 100 mol of the second subcomponent MnO ₂ : 0.5 mol, V ₂ O ₅ : 0 mol, the third subcomponent BaCO ₃ : 1.0 mol, the fourth sub-component SiO2: When 1.0 mol, shows the experimental example compositions according to the content of the first sub-component Li ₂ CO ₃ , Examples 10 to 18 of Table 4 are prototype multilayer ceramic capacitors (Proto -type MLCC).

When the content of Li ₂ CO ₃ is less than 0.2 mol (Examples 10 and 11), the problem of very low specific temperature resistance and high temperature withstand voltage occurs due to low sintering density, and when the content of Li ₂ CO ₃ exceeds 5.0 mol (implementation) Even in Example 18), it can be seen that a problem occurs in that the high temperature withstand voltage becomes lower than 50 V / µm.

When the Li ₂ CO ₃ content is in the range of 0.2 to 5.0 mol (Examples 12 to 17), the target temperature of the present invention is room temperature dielectric constant of 1000 or more, room temperature resistivity of 1E11 Ohm-cm or more, and high temperature of 200 ° C TCC (200 ° C) ± 22 It is possible to simultaneously implement all characteristics of less than% and high temperature 200 degrees withstand voltage of 50V / µm or more. At this time, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

Examples 19 to 25 of Table 3 is the base material 0.8BaTiO ₃ + 0.2 (Bi _0.5 Na _0.5 ) TiO ₃ 100 mol compared to the first sub-component Li ₂ CO ₃ : 1.8 mol, the second sub-component V ₂ O ₅ : 0 mol, the third When the subcomponent BaCO ₃ : 1.0 mol and the fourth subcomponent SiO ₂ : 1.0 mol, the experimental example compositions according to the content of the second subcomponent MnO ₂ are shown, and Examples 19 to 25 of Table 4 stack prototypes corresponding to these compositions. It shows the characteristics of a ceramic capacitor (Proto-type MLCC).

When the content of MnO ₂ is less than 0.2 mol (Example 19), the problem of very low temperature resistance and high temperature withstand voltage occurs, and even when the content of MnO ₂ exceeds 3.0 mol (Example 25), the room temperature specific resistance and high temperature It can be confirmed that the withstand voltage is lowered.

When the MnO ₂ content is in the range of 0.2 to 3.0 mol (Examples 20 to 24), the target dielectric constant of the present invention is 1000 or more, room temperature resistivity 1.0 × 10 ¹¹ Ohm-cm or more, and high temperature 200 degrees TCC (200 ° C) ± It is possible to simultaneously implement all characteristics of less than 22% and high temperature 200 degrees withstand voltage of 50V / µm or more. At this time, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

Examples 26 to 30 of Table 3 is the base material 0.8BaTiO ₃ + 0.2 (Bi _0.5 Na _0.5 ) TiO ₃ 100 mol compared to the first sub-component Li ₂ CO ₃ : 1.8 mol, the third sub-component BaCO ₃ : 1.0 mol, the fourth sub-component SiO 2 : When 1.0 mol, the second sub-components MnO ₂ and V ₂ O ₅ together shows experimental example compositions, and Examples 26 to 30 of Table 4 are prototype multilayer ceramic capacitors corresponding to these compositions (Proto- type MLCC).

When Mn alone is added (Examples 20 to 24) or Mn and V are added together (Examples 26-30), it can be confirmed that almost the same characteristics are realized when the total content of the second subcomponent is the same based on at%. And when the total content of the second sub-component is in the range of 0.2 to 3.0 at% based on at% (Examples 20 to 24 or Examples 26 to 30), the target temperature of the present invention is room temperature dielectric constant of 1000 or more and room temperature resistivity of 1.0 × 10 ¹¹ More than Ohm-cm, high temperature 200 degrees TCC (200 ℃) less than ± 22%, and high temperature 200 degrees withstand voltage 50V / µm or more can be simultaneously implemented. At this time, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

Examples 31 to 39 in Table 5 are the first subcomponent Li ₂ CO ₃ : 1.8 mol, the second subcomponent MnO ₂ : 0.5 mol, V ₂ O ₅ compared to the base material of 0.8BaTiO ₃ + 0.2 (Bi _0.5 Na _0.5 ) TiO ₃ 100 mol : 0 mol, 4th sub-component SiO ₂ : When 1.0 mol, shows the experimental example compositions according to the content of the third sub-component BaCO ₃ , and 31 to 39 in Table 6 are prototype multilayer ceramic capacitors (Proto- type MLCC).

When the content of the third subcomponent BaCO ₃ is less than 0.2 mol (Example 31), a problem of low high temperature withstand voltage occurs, and even when the content of BaCO ₃ exceeds 10.0 mol (Example 39), the sintering density is low and still high temperature. It can be confirmed that the withstand voltage is lowered. When the content of BaCO ₃ is in the range of 0.2 to 10.0 mol (Examples 32 to 38), the target dielectric constant of the present invention is 1000 or more, the room temperature resistivity is 1.0 × 10 ¹¹ Ohm-cm or more, and the high temperature is 200 degrees TCC (200 ℃) Simultaneous implementation of all characteristics of less than ± 22% and high temperature 200 degrees withstand voltage of 50V / µm or more. At this time, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

Examples 40 to 46 of Table 5 are the base material 0.8BaTiO ₃ + 0.2 (Bi _0.5 Na _0.5 ) TiO ₃ 100 mol compared to the first subcomponent Li ₂ CO ₃ : 1.8 mol, the second subcomponent MnO ₂ : 0.5 mol, V ₂ O ₅ : 0 mol, the third subcomponent BaCO ₃ : When 1.0 mol, shows the experimental example compositions according to the content of the fourth subcomponent SiO ₂ , and 40 to 46 in Table 6 are prototype multilayer ceramic capacitors corresponding to these compositions (Proto- type MLCC).

In the case where the content of the fourth subcomponent SiO ₂ is less than 0.2 mol (Examples 40 and 41), the problem of low sintering density and low temperature resistivity and high temperature withstand voltage occurs, and when the content of SiO ₂ exceeds 5.0 mol (Example 46) Also, due to the generation of secondary phases, it can be confirmed that the high temperature withstand voltage is also lowered. When the SiO ₂ content is in the range of 0.2 to 5.0 mol (Examples 42 to 45), the target dielectric constant of the present invention is 1000 or more, room temperature resistivity 1.0 × 10 ¹¹ Ohm-cm or more, and high temperature 200 degrees TCC (200 ℃) ± It is possible to simultaneously implement all characteristics of less than 22% and high temperature 200 degrees withstand voltage of 50V / µm or more. At this time, it can be seen that the area ratio of the second crystal grain to the unit area falls within a range of 5 to 50%.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is limited by the appended claims. Therefore, it will be apparent to those skilled in the art that various forms of substitution, modification, and modification are possible without departing from the technical spirit of the present invention as set forth in the claims. It will be said to belong to the technical idea described in.

100: multilayer ceramic capacitor 110: ceramic body
111: dielectric layers 121, 122: first and second internal electrodes
131, 132: first and second external electrodes

Claims (12)

The first main component and _a Na _.5+ Bi _{0 0 .5+ a} TiO and a second principal component represented by _3, (1-z) represented by BaTiO ₃ BaTiO ₃ - zBi _{0 .5+ a} Na _{0 .5+} base material powder represented by _a TiO ₃ (provided that said z is 0.05≤z≤0.5, wherein a is -0.025≤a≤0.025) includes,
When the grains having a Bi content of less than 1.0 at% and the Na content of less than 5.0 at% are called first crystal grains, and the grains having a Bi content of 1.0 to 70 at% and Na content of 5.0 to 70 at% are referred to as second crystal grains,
A dielectric ceramic composition having an area ratio of the second crystal grains to a unit area of 5.0 to 50%. According to claim 1,
A dielectric ceramic composition comprising 0.2 to 5.0 mol of Li ₂ CO ₃ as a first subcomponent with respect to 100 mol of a base powder. According to claim 1,
MnO ₂ as second subcomponent Or V ₂ O _{5 The} dielectric ceramic composition containing 0.2 to 3.0 mol with respect to 100 mol of the base powder. According to claim 1,
Dielectric ceramic composition containing 0.2 to 10.0 mol based on 100 mol of BaCO ₃ as a third sub-component. According to claim 1,
A dielectric ceramic composition containing 0.2 to 5.0 mol of SiO ₂ as a fourth subcomponent relative to 100 mol of the base powder. A ceramic body in which dielectric layers and first and second internal electrodes are alternately stacked; And
Includes; first and second external electrodes formed on both ends of the ceramic body and electrically connected to the first and second internal electrodes.
When the dielectric layer has a Bi content of less than 1.0 at% and a Na content of less than 5.0 at%, the first grain is referred to as a Bi content of 1.0 to 70 at% and a Na content of 5.0 to 70 at% is a second grain. A multilayer ceramic capacitor having an area ratio of the second crystal grain to a unit area of 5.0 to 50%. The method of claim 6,
It said dielectric layer comprises a second principal component represented by the first principal component and _{Bi 0 .5+ a Na 0 .5+ a} TiO 3 represented by _{BaTiO 3, (1-z)} BaTiO 3 - zBi _{0 .5+ a} Na _{0 .5+} base material powder represented by _a TiO ₃ using the dielectric ceramic composition containing (where z is the 0.05≤z≤0.5, wherein a is -0.025≤a≤0.025) Multilayer ceramic capacitor formed by. The method of claim 7,
The dielectric ceramic composition is a multilayer ceramic capacitor containing 0.2 to 5.0 mol of Li ₂ CO ₃ as a first subcomponent with respect to 100 mol of a base powder. The method of claim 7,
The dielectric ceramic composition has MnO as a second subcomponent₂ Or V₂O₅Multilayer ceramic capacitor containing 0.2 to 3.0 mol with respect to 100 mol of the base powder. The method of claim 7,
The dielectric ceramic composition is a multilayer ceramic capacitor containing BaCO ₃ as a third subcomponent from 0.2 to 10.0 mol with respect to 100 mol of the base powder. The method of claim 7,
The dielectric ceramic composition is a multilayer ceramic capacitor containing 0.2 to 5.0 mol of SiO ₂ as a fourth subcomponent with respect to 100 mol of the base powder. The method of claim 6,
The first and second internal electrodes include copper (Cu).

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