KR102592496B1 - Dielectric ceramic material for high temperature and high voltage and its manufacturing method - Google Patents

Abstract

The present invention relates to a dielectric ceramic material for high temperature and high voltage and a manufacturing method thereof. One aspect of the present invention provides a dielectric ceramic material containing a compound represented by the following formula (1).
[Formula 1]
(1-y)[(BiNa) _0.5-x La _x TiO ₃ ]-yCaZrO ₃
Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

Description

Dielectric ceramic material for high temperature and high voltage and manufacturing method thereof {DIELECTRIC CERAMIC MATERIAL FOR HIGH TEMPERATURE AND HIGH VOLTAGE AND ITS MANUFACTURING METHOD}

The present invention relates to a dielectric ceramic material for high temperature and high voltage and a method of manufacturing the same.

A multi-layer ceramic capacitor (MLCC) is an electronic device used to store electrical energy as a high-dielectric constant capacitor with a multi-layered structure in which several hundred or more layers of ceramic dielectric and internal metal electrodes intersect.

Recently, as the demand for electric vehicles has increased and the electronicization of automobiles has accelerated, the demand for automotive MLCCs that can operate normally in heat-generating areas (above 150 ℃) such as automobile engines and transmissions is increasing. However, they are still capable of operating above 150 ℃. And there are no capacitors with high reliability.

In order to develop high-reliability capacitors, dielectric materials with small dielectric constant changes up to high temperatures, low dielectric loss, and high voltage characteristics are essential.

To this end, the development of high dielectric constant dielectrics based on BaTiO ₃ (BT) is actively underway for high temperature stability. For example, various elements (Mg, Gd, Dy, Y, Mg, Mn, V, Zn) are intentionally used to form a core. -There is a known method of lowering the temperature dependence of the dielectric constant by controlling the dielectric constant of the base material by creating shell-shaped crystal grains and shifting the dielectric Curie temperature.

However, the development of dielectric ceramic materials that can overcome the temperature limit of 125°C of commercial capacitors is still insufficient, and there is a need to quickly develop dielectric ceramic materials that can be used in high-temperature, high-voltage capacitors.

The above-mentioned background technology is possessed or acquired by the inventor in the process of deriving the disclosure of the present application, and cannot necessarily be said to be known technology disclosed to the general public before the present application.

(Patent Document 1) KR 10-2017-0042713 A
(Patent Document 2) KR 10-2009-0088991 A
(Patent Document 3) CN 101033132 A

The present invention is intended to solve the above-mentioned problems, and the purpose of the present invention is to provide a dielectric ceramic material that can be applied to high temperature, high voltage capacitors and a method of manufacturing the same.

However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

One aspect of the present invention provides a dielectric ceramic material containing a compound represented by the following formula (1).

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

According to one embodiment, the compound represented by Formula 1 may be a single phase.

According to one embodiment, the compound represented by Formula 1 is a Bi _1/2 Na _1/2 TiO ₃ complex having an ABO ₃ perovskite structure, where Bi ³⁺ and Na ⁺ at the A-site are La ³ It may be simultaneously substituted with ⁺ .

According to one embodiment, the dielectric ceramic material has a temperature coefficient of capacitance (TCC) within ±17% and a dielectric loss (dissipation factor) of 2 in the temperature range of -55°C to 200°C. % or less, and the breakdown voltage (BDV: Break Down Voltage) may be 8.0 kV/mm or more.

According to one embodiment, the dielectric ceramic material has a temperature coefficient of capacitance (TCC) within ±15% and a dielectric loss (dissipation factor) of 1% in a temperature range of 25°C to 200°C. or less, and the breakdown voltage (BDV: Break Down Voltage) may be 8.8 kV/mm or more.

Another aspect of the present invention is Bi ₂ O ₃ powder, Na ₂ CO ₃ powder, La ₂ O ₃ powder, TiO ₂ powder, CaCO ₃ powder and mixing ZrO ₂ powder to prepare a powder mixture; Ball milling and drying the powder mixture; Calcining the dried powder mixture; sieving the calcined powder mixture; Pressuring and molding the filtered powder mixture to form pellets; and sintering the filtered powder mixture. A method for manufacturing a dielectric ceramic material is provided.

According to one embodiment, the ball milling is performed using zirconia balls for 10 to 30 hours after adding the powder mixture to ethanol, and the drying is performed at a temperature of 80 ° C. to 120 ° C. for 10 hours to 30 hours. It could be something you do for 30 hours.

According to one embodiment, the calcination step is performed at a temperature of 600°C to 1200°C for 1 hour to 3 hours, and the sintering step is performed at a temperature of 800°C to 1500°C for 1 hour to 3 hours. It may be done.

According to one embodiment, the size of the sieved powder mixture may be 10 ㎛ to 200 ㎛.

According to one embodiment, the dielectric ceramic material may include a compound represented by the following formula (1).

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

Another aspect of the present invention provides a multilayer ceramic capacitor including the dielectric ceramic material or the dielectric ceramic material manufactured by the manufacturing method.

According to one embodiment, the capacitor may be for electrical purposes.

The dielectric ceramic material according to the present invention simultaneously replaces Bi ³⁺ and Na ⁺ of the A-site of the Bi _1/2 Na _1/2 TiO ₃ composite with a perovskite structure with La ³⁺ and is used for temperature compensation. By including a compound formed by mixing the material CaZrO ₃ , the capacitance temperature coefficient, high temperature dielectric loss, and breakdown voltage characteristics are improved over a wide temperature range, including the high temperature range.

In addition, the dielectric ceramic material according to the present invention can be applied to capacitors for high temperature and high voltage, and in particular, it satisfies EIA standards X8R and X9R, so it can be used in MLCC for automotive applications.

1 is a flowchart showing the manufacturing process of a dielectric ceramic material according to an embodiment of the present invention.
Figure 2 shows the results of XRD analysis according to the ratio of La substituted for Bi and Na sites and the molar ratio of added CaZrO ₃ in the BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.
Figure 3 shows the results of XRD analysis when, in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric, La is simultaneously substituted at the Bi and Na sites or when only one site is substituted at the A-site.
Figure 4 shows the results of SEM image analysis when La is simultaneously substituted at the Bi and Na sites or when only one site is substituted at the A-site in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.
Figure 5 shows the dielectric constant according to temperature, by the ratio of La substituted for Bi and Na sites, and by the molar ratio of added CaZrO ₃ in the BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.
Figure 6 shows the dielectric constant according to temperature for each La substitution site in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.
Figure 7 shows (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material when y is 0.1 and x is 0.04 (BNLT4-10CZ) - In the temperature range of 100 ℃ to 500 ℃, the temperature coefficient of capacitance (TCC) and dielectric loss (Dissipation Factor) are shown.
Figure 8 shows (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material when y is 0.1 and x is 0.02 (BNLT2-10CZ) - In the temperature range of 100 ℃ to 500 ℃, the temperature coefficient of capacitance (TCC) and dielectric loss (Dissipation Factor) are shown.
Figure 9 shows the breakdown voltage (BDV: Break Down Voltage) of 0.9[(BiNa) _0.5 TiO ₃ ]-0.1CaZrO ₃ (BNLT0-10CZ) dielectric ceramic material.
Figure 10 shows the breakdown voltage (BDV: Break Down Voltage) of 0.9[(BiNa) _0.49 La _0.02 TiO ₃ ]-0.1CaZrO ₃ (BNLT2-10CZ) dielectric ceramic material.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, various changes can be made to the embodiments, so the scope of the patent application is not limited or limited by these embodiments. It should be understood that all changes, equivalents, or substitutes for the embodiments are included in the scope of rights.

The terms used in the examples are for descriptive purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the embodiments belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

In addition, when describing with reference to the accompanying drawings, identical components will be assigned the same reference numerals regardless of the reference numerals, and overlapping descriptions thereof will be omitted. In describing the embodiments, if it is determined that detailed descriptions of related known technologies may unnecessarily obscure the gist of the embodiments, the detailed descriptions are omitted.

Additionally, in describing the components of the embodiment, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being "connected," "coupled," or "connected" to another component, that component may be directly connected or connected to that other component, but there is no need for another component between each component. It should be understood that may be “connected,” “combined,” or “connected.”

Components included in one embodiment and components including common functions will be described using the same names in other embodiments. Unless stated to the contrary, the description given in one embodiment may be applied to other embodiments, and detailed description will be omitted to the extent of overlap.

One aspect of the present invention provides a dielectric ceramic material containing a compound represented by the following formula (1).

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

The ceramic composition according to the present invention has the effect of producing a dielectric ceramic material for high temperature and high voltage by containing the compound represented by Chemical Formula 1.

According to one embodiment, the compound represented by Formula 1 may be a single phase.

Consisting of a single phase may mean that it consists of one phase and is not separated into two or more phases.

In the compound represented by Formula 1, the range of x and y may be a range in which the compound is formed as a single phase, and if x or y is outside the above range, a secondary phase may be formed. there is.

In the compound represented by Formula 1, CaZrO ₃ is a temperature compensation material and plays a role in improving the temperature coefficient of capacitance (TCC), dielectric loss (DF), and dielectric breakdown voltage (BDV) of the dielectric.

In order for a dielectric to be used at high temperatures, the temperature stability of the dielectric constant must be good, and the dielectric loss must also be small within the operating temperature range. However, most dielectrics have good dielectric constant temperature stability, but dielectric loss tends to increase rapidly at temperatures above 200 ℃, making it difficult to use them as high-temperature dielectrics.

The dielectric ceramic material according to the present invention has the feature of reducing dielectric loss while ensuring temperature stability of the dielectric constant at high temperatures of the dielectric manufactured therefrom by containing the compound represented by the above formula (1).

According to one embodiment, the compound represented by Formula 1 is a Bi _1/2 Na _1/2 TiO ₃ complex having an ABO ₃ perovskite structure, where Bi ³⁺ and Na ⁺ at the A-site are La ³ It may be simultaneously substituted with ⁺ .

The Bi _1/2 Na _1/2 TiO ₃ dielectric has an ABO ₃ perovskite structure, and Bi ³⁺ and Na ⁺ are present at the A-site. By simultaneously replacing some of Bi ³⁺ and Na ⁺ located at the A-site with La ³⁺ , the temperature coefficient of capacitance (TCC), dielectric loss (DF), and dielectric breakdown voltage (BDV) of the dielectric can all be improved. there is.

If only one site among Bi ³⁺ and Na ⁺ in the A-site is substituted with La ³⁺ , a secondary phase may be formed or a Zr-rich phase may occur, and temperature coefficient of capacitance (TCC) and dielectric loss may occur. (DF), the breakdown voltage (BDV) improvement effect may be reduced.

In particular, substitution of La serves as a key factor in improving dielectric loss (DF) and dielectric breakdown voltage (BDV).

According to one embodiment, the dielectric ceramic material has a temperature coefficient of capacitance (TCC) within ±17% and a dielectric loss (dissipation factor) of 2 in the temperature range of -55°C to 200°C. % or less, and the breakdown voltage (BDV: Break Down Voltage) may be 8.0 kV/mm or more.

According to one embodiment, the dielectric ceramic material has a temperature coefficient of capacitance (TCC) within ±15% and a dielectric loss (dissipation factor) of 1% in a temperature range of 25°C to 200°C. or less, and the breakdown voltage (BDV: Break Down Voltage) may be 8.8 kV/mm or more.

The temperature coefficient of capacitance (TCC) refers to the change in capacitance with respect to the surrounding temperature.

The dielectric loss (dissipation factor) refers to the loss coefficient generated by the equivalent series circuit resistance of a capacitor in an alternating current circuit, and is generally expressed as tanδ. Dielectric loss is proportional to power loss, and high dielectric loss has low insulation resistance, which causes destruction or deterioration during the high-voltage charging process or repetitive voltage charging process, thereby reducing the lifespan.

The breakdown voltage (BDV: Break Down Voltage) refers to the voltage at which breakdown voltage occurs.

Another aspect of the present invention is Bi ₂ O ₃ powder, Na ₂ CO ₃ powder, La ₂ O ₃ powder, TiO ₂ powder, CaCO ₃ powder and mixing ZrO ₂ powder to prepare a powder mixture; Ball milling and drying the powder mixture; Calcining the dried powder mixture; sieving the calcined powder mixture; Pressuring and molding the filtered powder mixture to form pellets; and sintering the filtered powder mixture. A method for manufacturing a dielectric ceramic material is provided.

According to one embodiment, the step of preparing the powder mixture includes the base material powder, Bi ₂ O ₃ powder, Na ₂ CO ₃ powder, La ₂ O ₃ powder, TiO ₂ powder, CaCO ₃ powder. And ZrO ₂ powder may be weighed and mixed according to the stoichiometric ratio.

That is, each component powder may be weighed and mixed to form a compound represented by the following formula (1).

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

According to one embodiment, the ball milling is performed using zirconia balls for 10 to 30 hours after adding the powder mixture to ethanol, and the drying is performed at a temperature of 80 ° C. to 120 ° C. for 10 hours to 30 hours. It could be something you do for 30 hours.

Preferably, the ball milling may be performed using zirconia balls for 20 to 30 hours after adding the powder mixture to ethanol, and the drying may be performed at a temperature of 80 ℃ to 120 ℃ for 20 hours to 30 hours. It could be something you do for 30 hours.

According to one embodiment, the calcination step is performed at a temperature of 600°C to 1200°C for 1 hour to 3 hours, and the sintering step is performed at a temperature of 800°C to 1500°C for 1 hour to 3 hours. It may be done.

Preferably, the calcination step is performed at a temperature of 800 ℃ to 1000 ℃ for 1 hour to 3 hours, and the sintering step is performed at a temperature of 1000 ℃ to 1200 ℃ for 1 hour to 3 hours. It may be.

The final product obtained through the sintering step may have a perovskite crystal structure.

If the sintering step is performed at a temperature below the above temperature range, the perovskite crystallinity may be lowered, and if the sintering step is performed at a temperature exceeding the above temperature range, the particle size may become too large or defects within the structure may occur. You can.

The sintering step may be performed in air, and may be performed to accurately control the stoichiometric ratio.

The sintering step is not performed in an inert atmosphere, because the stoichiometric ratio may vary due to volatilization of Bi during sintering in an inert atmosphere.

According to one embodiment, the step of sieving the calcined powder mixture may be performed to increase particle size uniformity.

According to one embodiment, the size of the sieved powder mixture may be 10 ㎛ to 200 ㎛.

Preferably, the size of the sieved powder mixture may be 10 ㎛ to 150 ㎛, more preferably 10 ㎛ to 120 ㎛.

According to one embodiment, after the sintering step, the diameter of the particles formed may be 1 ㎛ to 5 ㎛.

Preferably, the diameter of the formed particles may be 1.5 ㎛ to 3 ㎛, more preferably 1.5 ㎛ to 2.5 ㎛.

According to one embodiment, the dielectric ceramic material may include a compound represented by the following formula (1).

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

Here, x is a real number from 0 to 0.04, and y is a real number from 0.05 to 0.1.

Another aspect of the present invention is that, manufactured by the above manufacturing method, the temperature coefficient of capacitance (TCC) is within ±17% in the temperature range of -55 ℃ to 200 ℃, and the dielectric loss (Dissipation Factor) is within ±17%. ) is less than 2% and the breakdown voltage (BDV: Break Down Voltage) is more than 8.0 kV/mm.

According to one embodiment, the dielectric ceramic material has a temperature coefficient of capacitance (TCC) within ±15% and a dielectric loss (dissipation factor) of 1% in a temperature range of 25°C to 200°C. or less, and the breakdown voltage (BDV: Break Down Voltage) may be 8.8 kV/mm or more.

Another aspect of the present invention provides a multilayer ceramic capacitor including the dielectric ceramic material or the dielectric ceramic material manufactured by the manufacturing method.

According to one embodiment, the capacitor may be for electrical purposes.

Since the dielectric ceramic material satisfies the EIA standards X8R and X9R for dielectric ceramic materials, it can be used in high temperature, high voltage capacitors for electrical applications.

The electrical capacitor may be capable of operating at 150°C or higher and 200°C or higher.

Hereinafter, the present invention will be described in more detail through examples and comparative examples.

However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited to the following examples.

<Example 1> Manufacturing of dielectric ceramic material

Bi ₂ O ₃ powder, Na ₂ CO ₃ powder, La ₂ O ₃ powder, TiO ₂ powder, CaCO ₃ powder and ZrO ₂ powder were weighed and mixed according to the stoichiometric ratio.

After adding ethanol to the powder mixture, wet ball milling was performed for 24 hours using zirconia balls, and dried at a temperature of 100° C. for 24 hours.

The dried mixture was calcined at a temperature of 850°C for 2 hours, sieved to obtain a powder mixture of less than 100 ㎛, and then placed in a mold with a diameter of 12 mm and a thickness of 1 mm and formed into a pellet under 70 MPa pressure. . The pellets were then sintered at 1100-1170 °C for 2 hours.

1 is a flowchart showing the manufacturing process of a dielectric ceramic material according to an embodiment of the present invention.

Referring to Figure 1, the manufacturing process of the dielectric ceramic material according to the present invention proceeds in the following order: ball milling of the powder mixture, drying, calcining, sieving, pressing to form pellets, and sintering. can understand.

Here, the powder mixture is mixed by weighing the base powder according to the stoichiometric ratio.

<Experimental Example 1> Phase analysis of dielectric ceramic material

In a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric, phase changes were analyzed depending on the ratio of La substituted for Bi and Na sites and the molar ratio of added CaZrO ₃ .

Figure 2 shows the results of XRD analysis according to the ratio of La substituted for Bi and Na sites and the molar ratio of added CaZrO ₃ in the BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.

In the XRD graph, based on Chemical Formula 1, the chemical formula of the dielectric material according to each stoichiometric ratio is shown in Table 1.

[Formula 1]

(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃

x y Chemical composition BNLT0-5CZ 0 0.05 0.95[Bi _0.5 Na _0.5 TiO ₃ ]-0.05CaZrO ₃ BNLT0-10CZ 0 0.1 0.9[Bi _0.5 Na _0.5 TiO ₃ ]-0.1CaZrO ₃ BNLT2-10CZ 0.02 0.1 0.9[(Bi _0.49 Na _0.49 )La _0.02 TiO ₃ ]-0.1CaZrO ₃ BNLT4-10CZ 0.04 0.1 0.9[(Bi _0.48 Na _0.48 )La _0.04 TiO ₃ ]-0.1CaZrO ₃

Referring to FIG. 2, _it can _be seen that in the (1-y)[(BiNa) _{0.5(1-x) La} You can.

In addition, when La was simultaneously substituted at the Bi and Na sites, it was confirmed that the substitution was successful up to x of 0.04, and if it was higher than that, a secondary phase was created.

Figure 3 shows the results of XRD analysis when, in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric, La is simultaneously substituted at the Bi and Na sites or when only one site is substituted at the A-site.

In the XRD graph, the chemical formula of the dielectric material according to each stoichiometric ratio is shown in Table 2.

x y Chemical composition BNLT2-10CZ_Bi, Na
(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ 0.02 0.1 0.9[(Bi _0.49 Na _0.49 )La _0.02 TiO ₃ ]-0.1CaZrO ₃ BNLT2-10CZ-Bi
(1-y)[(Bi _0.5-x Na _0.5 La _x )TiO ₃ ]-yCaZrO ₃ 0.02 0.1 0.9[(Bi _0.48 Na _0.5 La _0.02 )TiO ₃ ]-0.1CaZrO ₃ BNLT2-10CZ-Na
(1-y)[(Bi _0.5 Na _0.5-x La _x )TiO ₃ ]-yCaZrO ₃ 0.02 0.1 0.9[(Bi _0.5 Na _0.48 La _0.02 )TiO ₃ ]-0.1CaZrO ₃ BNLT2-10CZ-Ca
(1-y)[(BiNa) _0.5 La _x TiO ₃ ]-yCa _1-x ZrO ₃ 0.02 0.1 0.9[(Bi _0.5 Na _0.5 )La _0.02 TiO ₃ ]-0.1Ca _0.98 ZrO ₃

Referring to Figure 3, it can be seen that a secondary phase is created when only one site of each A-site is substituted for La, rather than at the Bi and Na sites simultaneously, and only the Na site is substituted.

Figure 4 shows the results of SEM image analysis when La is simultaneously substituted at the Bi and Na sites or when only one site is substituted at the A-site in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.

Referring to Figure 4, it can be seen that a Zr-rich phase is found when only the Bi site is replaced by La.

<Experimental Example 2> Analysis of electrical properties of dielectric ceramic material

In a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric, the electrical properties were analyzed according to the ratio of La substituted for Bi and Na sites and the molar ratio of added CaZrO ₃ .

The dielectric constant was measured in the temperature range from room temperature to 400°C using an impedance measurement equipment HP-4192A (Hewlett-Packard Company) using a self-made sample jig.

TCC and DF were calculated from the temperature-dependent dielectric constant and dielectric loss graph using the formulas below.

DF = tanδ x 100 [%]

The breakdown voltage was calculated as the voltage at which the sample is energized while applying up to 10 kV/mm at a rate of 0.5 kV/s using the short time method.

Figure 5 shows the dielectric constant according to temperature, by the ratio of La substituted for Bi and Na sites, and by the molar ratio of added CaZrO ₃ in the BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.

Here, the dielectric was manufactured at a sintering temperature of 1150° C. and a sintering time of 2 hours.

Referring to FIG. 5, in the (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material, when y is 0.1 and x is 0.02, dielectric constant characteristics according to temperature It can be seen that this is optimally expressed.

Figure 6 shows the dielectric constant according to temperature for each La substitution site in a BNT (Bi _1/2 Na _1/2 TiO ₃ )-based dielectric.

Here, the dielectric was manufactured at a sintering temperature of 1150° C. and a sintering time of 2 hours.

Referring to FIG. 6, it can be seen that when La substitutes Bi and Na simultaneously, the dielectric constant characteristics according to temperature are optimally expressed.

Figure 7 shows (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material when y is 0.1 and x is 0.04 (BNLT4-10CZ) - In the temperature range of 100 ℃ to 500 ℃, the temperature coefficient of capacitance (TCC) and dielectric loss (Dissipation Factor) are shown.

Referring to Figure 7, it can be seen that in the temperature range of -55°C to 200°C, TCC was 17% and DF was 1.4%.

Figure 8 shows (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material when y is 0.1 and x is 0.02 (BNLT2-10CZ) - In the temperature range of 100 ℃ to 500 ℃, the temperature coefficient of capacitance (TCC) and dielectric loss (Dissipation Factor) are shown.

Referring to Figure 8, it can be seen that TCC was 14.5% and DF was 1% in the temperature range from room temperature to 200°C.

In particular, it can be confirmed that TCC 15% is satisfied in the temperature range of -55 ℃ to 450 ℃.

Figure 9 shows the breakdown voltage (BDV: Break Down Voltage) of 0.9[(BiNa) _0.5 TiO ₃ ]-0.1CaZrO ₃ (BNLT0-10Cz) dielectric ceramic material.

Referring to FIG. 9, in the (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material, when y is 0.1 and x is 0 (BNLT0-10CZ) It can be seen that the insulation breakdown voltage is 8 kV/mm.

Figure 10 shows the breakdown voltage (BDV: Break Down Voltage) of 0.9[(BiNa) _0.49 La _0.02 TiO ₃ ]-0.1CaZrO ₃ (BNLT2-10CZ) dielectric ceramic material.

Referring to FIG. 10, in the (1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃ dielectric ceramic material, when y is 0.1 and x is 0.02 (BNLT2-10CZ) It can be confirmed that the insulation breakdown voltage is 8.8 kV/mm.

Through this, it can be seen that the dielectric breakdown voltage is improved when La simultaneously substitutes for Bi and Na sites.

Although the embodiments have been described with limited drawings as described above, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent.

Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the following claims.

Claims (12)

Containing a compound represented by Formula 1 below,
As a dielectric ceramic material,
- in the temperature range from 55 ℃ to 200 ℃,
The temperature coefficient of capacitance (TCC) is within ±17%,
Dielectric loss (dissipation factor) is less than 2%,
The breakdown voltage (BDV: Break Down Voltage) is 8.0 kV/mm or more,
Dielectric ceramic material:
[Formula 1]
(1-y)[(BiNa) _0.5(1-x) La _x TiO ₃ ]-yCaZrO ₃
The x is a real number from 0 to 0.04,
The y is a real number of 0.05 to 0.1.
According to paragraph 1,
The compound represented by Formula 1 is,
It is a single phase,
Dielectric ceramic material.
According to paragraph 1,
The compound represented by Formula 1 is,
In the Bi _1/2 Na _1/2 TiO ₃ complex with an ABO ₃ perovskite structure, Bi ³⁺ and Na ⁺ at the A-site are simultaneously substituted with La ³⁺ .
Dielectric ceramic material.
delete According to paragraph 1,
In the temperature range of 25 ℃ to 200 ℃,
The temperature coefficient of capacitance (TCC) is within ±15%,
Dielectric loss (dissipation factor) is less than 1%,
The breakdown voltage (BDV: Break Down Voltage) is 8.8 kV/mm or more,
Dielectric ceramic material.
Bi ₂ O ₃ powder, Na ₂ CO ₃ powder, La ₂ O ₃ powder, TiO ₂ powder, CaCO ₃ powder and mixing ZrO ₂ powder to prepare a powder mixture;
Ball milling and drying the powder mixture;
Calcining the dried powder mixture;
sieving the calcined powder mixture;
Pressuring and molding the filtered powder mixture to form pellets; and
Comprising: sintering the filtered powder mixture;
A method of manufacturing the dielectric ceramic material of claim 1.
According to clause 6,
The ball milling is performed for 10 to 30 hours using zirconia balls after adding the powder mixture to ethanol,
The drying is performed at a temperature of 80 ℃ to 120 ℃ for 10 to 30 hours,
Manufacturing method of dielectric ceramic material.
According to clause 6,
The calcination step is performed at a temperature of 600 ℃ to 1200 ℃ for 1 hour to 3 hours,
The sintering step is performed at a temperature of 800 ℃ to 1500 ℃ for 1 hour to 3 hours,
Manufacturing method of dielectric ceramic material.
According to clause 6,
The size of the sieved powder mixture is 10 ㎛ to 200 ㎛,
Manufacturing method of dielectric ceramic material.
According to clause 6,
The dielectric ceramic material includes a compound represented by the following formula (1):
Manufacturing method of dielectric ceramic material:
[Formula 1]
(1-y)[(BiNa) _0.5-x La _x TiO ₃ ]-yCaZrO ₃
The x is a real number from 0 to 0.04,
The y is a real number of 0.05 to 0.1.
Containing the dielectric ceramic material of claim 1 or the dielectric ceramic material manufactured by the manufacturing method of claim 6,
Multilayer ceramic capacitors.
According to clause 11,
The capacitor is for battlefield use,
Multilayer ceramic capacitors.

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