JP2023184543A - Dielectric ceramic composition and multilayer ceramic capacitor comprising the same - Google Patents

Abstract

To provide a dielectric ceramic composition capable of improving reliability, and to provide a multilayer ceramic capacitor comprising the same.SOLUTION: A dielectric ceramic composition according to one embodiment of this invention includes a BaTiO3-based base material main ingredient and an accessory ingredient, wherein: the accessory ingredient includes a trivalent lanthanide rare earth element A and terbium (Tb) as rare earth elements; and a ratio (Tb/A) of a content of terbium (Tb) to the content of the trivalent lanthanide rare earth element A satisfies 0.15≤Tb/A<0.50. A multilayer ceramic capacitor comprising the same is also provided.SELECTED DRAWING: Figure 3

Description

The present invention relates to a dielectric ceramic composition that can improve reliability and a multilayer ceramic capacitor containing the same.

Generally, electronic components using ceramic materials, such as capacitors, inductors, piezoelectric elements, varistors, or thermistors, have a ceramic body made of a ceramic material, an internal electrode formed inside the body, and a ceramic body connected to the internal electrode. , and an external electrode disposed on the surface of the ceramic body.

Recently, as electronic products have become smaller and more multi-functional, chip components have also become smaller and more sophisticated, so there is a demand for multilayer ceramic capacitors that are smaller in size and have higher capacity. .

One method for achieving both miniaturization and high capacity of a multilayer ceramic capacitor is to reduce the thickness of the internal dielectric layer and electrode layer and laminate a large number of them. Further, the current thickness of the dielectric layer is approximately 0.6 μm, and development to a thinner level is being continued.

Under these circumstances, ensuring the reliability of the dielectric layer has become an important issue for dielectric materials, and at the same time, the defective rate increases due to deterioration of the insulation resistance of the dielectric, making quality and yield control difficult. This is emerging as a problem.

In order to solve this problem, a new method is required that can ensure high reliability not only in terms of the structure of multilayer ceramic capacitors, but also in particular in terms of dielectric composition.

If a dielectric composition that can further raise the reliability level at the current level is secured, it will be possible to manufacture a multilayer ceramic capacitor with even thinner layers.

An object of the present invention is to provide a dielectric ceramic composition that can improve reliability and a multilayer ceramic capacitor containing the same.

One embodiment of the present invention includes a BaTiO ₃ -based base material main component and a subcomponent, the subcomponent including a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements, and the above trivalent lanthanum group rare earth element A and terbium (Tb). A dielectric ceramic composition is provided in which the ratio of the terbium (Tb) content to the element A content (Tb/A) satisfies 0.15≦Tb/A<0.50.

Another embodiment of the present invention includes a ceramic body including a dielectric layer, and a first internal electrode and a second internal electrode that are arranged to face each other with the dielectric layer interposed therebetween; a first external electrode disposed on the outside and electrically connected to the first internal electrode; and a second external electrode electrically connected to the second internal electrode, and the dielectric layer has a dielectric layer. The dielectric ceramic composition includes a BaTiO ₃ base material main component and a subcomponent, and the subcomponent includes a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements, A multilayer ceramic capacitor is provided in which the ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) satisfies 0.15≦Tb/A<0.50.

According to one embodiment of the present invention, the dielectric ceramic composition contained in the dielectric layer in the ceramic body contains terbium (Tb), which is a new rare earth element, as a subcomponent, and the content thereof is controlled. This makes it possible to improve reliability by improving insulation resistance.

1 is a schematic perspective view showing a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II' in FIG. 1. FIG. 1 is a graph showing evaluation results of reliability tests (HALT) conducted under severe conditions according to examples and comparative examples of the present invention.

In the following, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Therefore, the shapes and sizes of elements in the drawings may be enlarged or reduced (or highlighted or simplified) for clearer explanation, and elements indicated by the same reference numerals on the drawings are the same. is an element of

FIG. 1 is a schematic perspective view showing a multilayer ceramic capacitor according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II' in FIG.

Referring to FIGS. 1 and 2, a multilayer ceramic capacitor 100 according to an embodiment of the present invention includes a dielectric layer 111 and first internal electrodes that are arranged to face each other with the dielectric layer 111 interposed therebetween. 121 and a second internal electrode 122; a first external electrode 131 disposed outside the ceramic body 110 and electrically connected to the first internal electrode 121; and a second internal electrode 122. and a second external electrode 132 electrically connected to the second external electrode 132 .

In the multilayer ceramic capacitor 100 according to an embodiment of the present invention, the "length direction" is the "L" direction in FIG. 1, the "width direction" is the "W" direction, and the "thickness direction" is the "T" direction. Define direction. Here, the "thickness direction" can be used in the same concept as the direction in which dielectric layers are stacked, that is, the "stacking direction."

Although the shape of the ceramic body 110 is not particularly limited, it may have a hexahedral shape as shown in the drawings.

One end of the plurality of internal electrodes 121 and 122 formed inside the ceramic body 110 is exposed on one surface of the ceramic body or the other surface opposite to the one surface.

The internal electrodes 121 and 122 may be a pair of a first internal electrode 121 and a second internal electrode 122 having different polarities.

One end of the first internal electrode 121 may be exposed on one surface of the ceramic body, and one end of the second internal electrode 122 may be exposed on the other surface opposite to the one surface.

First and second external electrodes 131 and 132 may be formed on one surface of the ceramic body 110 and the other surface opposite to the one surface, and may be electrically connected to the internal electrodes.

The materials forming the first and second internal electrodes 121 and 122 are not particularly limited, and the first and second internal electrodes 121 and 122 can be made of, for example, silver (Ag), lead (Pb), platinum (Pt). , nickel (Ni), and copper (Cu).

The first and second outer electrodes 131 and 132 may be electrically connected to the first and second inner electrodes 121 and 122 to form capacitance, and the second outer electrode 132 may be connected to a different potential from the first external electrode 131.

The conductive material contained in the first and second external electrodes 131 and 132 is not particularly limited, but nickel (Ni), copper (Cu), or an alloy thereof can be used.

The thickness of the first and second external electrodes 131 and 132 can be determined as appropriate depending on the application, and is not particularly limited, but may be, for example, 10 to 50 μm.

According to one embodiment of the present invention, the raw material for forming the dielectric layer 111 is not particularly limited as long as sufficient capacitance can be obtained, and for example, barium titanate (BaTiO ₃ ) powder may be used. good.

The material forming the dielectric layer 111 is powder such as barium titanate (BaTiO ₃ ) to which various additives, organic solvents, plasticizers, binders, dispersants, etc. are added depending on the purpose of the present invention. can be done.

The dielectric layer 111 may be in a sintered state and may be so integrated that the boundaries between adjacent dielectric layers cannot be seen.

First and second internal electrodes 121 and 122 may be formed on the dielectric layer 111, and the internal electrodes 121 and 122 are formed inside the ceramic body with one dielectric layer interposed therebetween by sintering. can be formed.

The thickness of the dielectric layer 111 can be arbitrarily changed depending on the capacitance design of the capacitor. In one embodiment of the present invention, the thickness of the dielectric layer after firing may preferably be 0.45 μm or less per layer.

Further, the thickness of the first and second internal electrodes 121 and 122 after firing may preferably be 0.45 μm or less per layer.

According to an embodiment of the present invention, the dielectric layer 111 includes a BaTiO ₃ base material main component and a subcomponent, and the subcomponent includes a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements. The dielectric ceramic composition includes a ratio (Tb/A) of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) satisfying 0.15≦Tb/A<0.50.

In particular, the trivalent lanthanum group rare earth element A may be dysprosium (Dy).

According to one embodiment of the present invention, the ratio (Tb/A) of the content of the terbium (Tb) to the content of the trivalent lanthanum group rare earth element A satisfies 0.15≦Tb/A<0.50. .

When the ratio of the terbium (Tb) content to the trivalent lanthanum group rare earth element A content (Tb/A) satisfies 0.15≦Tb/A<0.50, insulation resistance is improved, etc. It has an excellent reliability improvement effect.

In particular, the trivalent lanthanum group rare earth element A may be dysprosium (Dy), and the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is 0.15≦ When Tb/Dy<0.50 is satisfied, there is an excellent effect of improving reliability such as improving insulation resistance.

According to one embodiment of the present invention, the dielectric ceramic composition contained in the dielectric layer in the ceramic body contains a trivalent lanthanum group rare earth element A and terbium (Tb), which is a rare earth element, as subcomponents, and By controlling the ratio of the content of terbium (Tb), which is the rare earth element, to the trivalent lanthanum group rare earth element A, reliability such as an increase in insulation resistance can be improved.

If the ratio of the terbium (Tb) content to the trivalent lanthanum group rare earth element A content (Tb/A) is less than 0.15, the reliability improvement effect due to the addition of terbium (Tb) will not be effective. If the ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A is 0, that is, if terbium (Tb) is not added as in the conventional case, There may be no improvement in reliability and the defective rate may increase.

Further, if the ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) is 0.50 or more, a decrease in insulation resistance due to semiconductorization may occur. be.

The trivalent lanthanum group rare earth element A may be dysprosium (Dy), and the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is less than 0.15. The reliability improvement effect due to the addition of terbium (Tb) is slight, and when the ratio of the terbium (Tb) content to the dysprosium (Dy) content is 0, that is, as in the conventional case, If terbium (Tb) is not added, there is no effect of improving reliability and the defective rate may increase.

Furthermore, if the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is 0.50 or more, insulation resistance may decrease due to semiconductor formation.

According to an embodiment of the present invention, the total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or more per 100 mol of titanium (Ti) among the main components of the base material. It can be less than a molar amount.

In particular, the trivalent lanthanum group rare earth element A may be dysprosium (Dy).

Generally, a large amount of rare earth elements are added to ensure the reliability of the dielectric inside the multilayer ceramic capacitor.

Among these rare earth elements, dysprosium (Dy), when added to barium titanate (BaTiO ₃ ), which is the main component of the base material, becomes reliable by reducing the concentration of oxygen vacancy defects while replacing Ba-sites. It is known to be effective in improving sex.

On the other hand, when using a rare earth element with a larger ionic radius than dysprosium (Dy), such as lanthanum (La) or samarium (Sm), it is possible to more effectively replace Ba-sites, thereby eliminating oxygen vacancy defects. Although it is more effective in reducing the concentration, it has not yet reached a practical level due to the problem of a rapid drop in insulation resistance due to excessive semiconductorization.

Therefore, in order to minimize the concentration of oxygen vacancy defects in order to improve reliability and also to suppress semiconductor formation to ensure insulation resistance, dysprosium (Dy) has a larger ionic radius than dysprosium (Dy). It was thought that it would be better to use a rare earth element that does not have a large size difference from (Dy).

In addition, the fixed valence of common rare earth elements is +3, so when replacing Ba (+2), it has a single positive charge (D^・ _Ba ). If it can have a multi-valence of +4 like terbium (Tb), it can have a double positive charge (D ^... _Ba ), so the oxygen vacancy is The effect of reducing the concentration of hole defects can be doubled.

On the other hand, when ytterbium (Yb) has a variable valence of +2, it is neutral in charge when replacing Ba (+2), so it can be used to reduce the concentration of oxygen vacancies. It is known that adding ytterbium (Yb) for this reason further deteriorates reliability.

Therefore, although the ionic radius is larger than that of dysprosium (Dy), the element terbium (Tb), which has multiple atoms, is most effective in reducing the concentration of oxygen vacancy defects, without progressing to semiconductor formation to the extent that it reduces insulation resistance. As a result, it was expected that the reliability of the dielectric in multilayer ceramic capacitors could be greatly improved, and as a result, a dielectric ceramic composition containing both dysprosium (Dy) and terbium (Tb) was developed. Ta.

Conventionally, there have been attempts to add one or more of dysprosium (Dy), gadolinium (Gd), and terbium (Tb) as rare earth elements to dielectric ceramic compositions.

However, in the above conventional case, the above effects of terbium (Tb) are not recognized, and terbium (Tb) is simply described as a rare earth element or added only in small amounts, and terbium (Tb) is added to improve reliability. The reality is that no specific research has been conducted on the content of (Tb).

On the other hand, in one embodiment of the present invention, it was possible to find an optimal ratio of the amounts of dysprosium (Dy) and terbium (Tb) that exhibits an excellent effect on improving reliability.

According to an embodiment of the present invention, the total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or more per 100 mol of titanium (Ti) among the main components of the base material. By adjusting the amount to be less than molar, it is possible to improve reliability by increasing insulation resistance.

In the case where the trivalent lanthanum group rare earth element A is dysprosium (Dy), the total content of the dysprosium (Dy) and terbium (Tb) is 0.00% per 100 moles of titanium (Ti) among the main components of the base material. It is characterized by being 2 mol or more and 1.5 mol or less.

By adjusting the total content of dysprosium (Dy) and terbium (Tb) to be 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material, insulation can be achieved. This makes it possible to improve reliability by increasing resistance.

The higher the total content of rare earth elements, the more advantageous it is in terms of reliability, but as Tc moves to room temperature, the temperature characteristics decrease significantly, so the total content of dysprosium (Dy) and terbium (Tb) It is preferable to adjust the amount to 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material.

If the total content of dysprosium (Dy) and terbium (Tb) exceeds 1.5 mol per 100 mol of titanium (Ti) among the main components of the base material, the temperature coefficient of capacitance (TCC) etc. temperature characteristics may deteriorate.

On the other hand, if the total content of dysprosium (Dy) and terbium (Tb) is less than 0.2 mol per 100 mol of titanium (Ti) among the main components of the base material, reliability may decrease. There is.

As described above, the multilayer ceramic capacitor 100 according to an embodiment of the present invention is an ultra-small high-capacity product, in which the dielectric layer 111 has a thickness of 0.45 μm or less, and the first and second internal electrodes 121 have a thickness of 0.45 μm or less. , 122 is characterized in that it is 0.45 μm or less, but is not necessarily limited to this.

That is, since the multilayer ceramic capacitor 100 according to an embodiment of the present invention is an ultra-small high-capacity product, the thickness of the dielectric layer 111 and the first and second internal electrodes 121 and 122 is thinner than that of conventional products. In the case of products that use thin dielectric layers and internal electrodes, research to improve reliability such as insulation resistance has become a very important issue.

In other words, in the case of a conventional multilayer ceramic capacitor, the composition of the dielectric ceramic composition is Even in the same case as before, reliability was not a major problem.

However, in products to which thin dielectric layers and internal electrodes are applied, as in one embodiment of the present invention, the reliability of the multilayer ceramic capacitor is important. Therefore, it is necessary to adjust the composition of the dielectric ceramic composition.

That is, in one embodiment of the present invention, the total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more per 100 mol of titanium (Ti) among the main components of the base material. The ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) is 0.15≦Tb/A<0.50. By adjusting the dielectric layer 111 and the first and second internal electrodes 121 and 122 to be thin films with a thickness of 0.45 μm or less, reliability such as improved insulation resistance can be improved. be able to.

However, the above-mentioned thin film does not mean that the thickness of the dielectric layer 111 and the first and second internal electrodes 121 and 122 is 0.45 μm or less, but a dielectric film that is thinner than conventional products. It is best understood as a concept that includes body layers and internal electrodes.

Each component of the dielectric ceramic composition according to an embodiment of the present invention will be explained in more detail below.

a) Base material main component The dielectric ceramic composition according to one embodiment of the present invention may include a base material main component represented by BaTiO ₃ .

According to an embodiment of the present invention, the main components of the base material are BaTiO ₃ , (Ba _1-x Ca _x )(Ti _1-y Ca _y )O ₃ (where x is 0≦x≦0.3 , y is 0≦y≦0.1), (Ba _1-x Ca _x ) (Ti _1-y Zr _y )O ₃ (where x is 0≦x≦0.3, y is 0≦y≦ 0.5), and Ba(Ti _1-y Zr _y )O ₃ (where 0<y≦0.5), but is not necessarily limited thereto. isn't it.

The dielectric ceramic composition according to an embodiment of the present invention may have a room temperature dielectric constant of 2000 or more.

The main component of the base material is not particularly limited, but the main component powder may have an average particle size of 40 nm or more and 150 nm or less.

b) First subcomponent According to one embodiment of the present invention, the dielectric ceramic composition necessarily contains dysprosium (Dy) and terbium (Tb) as the first subcomponent elements, and 100 mol of the main base material component. 0.0 of the first subcomponent, which is an oxide or carbonate containing at least one of Y, Ho, Er, Ce, Nd, Pm, Eu, Gd, Tm, Yb, Lu, and Sm. It can further contain up to 4.0 mol.

In one embodiment of the present invention, the first subcomponent plays a role in preventing a decrease in reliability of a multilayer ceramic capacitor to which the dielectric ceramic composition is applied.

If the content of the first subcomponent exceeds 4.0 moles, problems may occur such as a decrease in reliability or a decrease in the dielectric constant of the dielectric ceramic composition, resulting in poor high-temperature withstand voltage characteristics. There is.

According to an embodiment of the present invention, the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) satisfies 0.15≦Tb/Dy<0.50. shall be.

By adjusting the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) to satisfy 0.15≦Tb/Dy<0.50, insulation resistance can be improved, etc. This makes it possible to improve reliability.

If the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is less than 0.15, the reliability improvement effect due to the addition of terbium (Tb) is small. When the ratio of the terbium (Tb) content to the dysprosium (Dy) content is 0, that is, when terbium (Tb) is not added as in the past, there is no improvement in reliability. This may result in an increase in the defective rate.

On the other hand, if the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is 0.50 or more, the insulation resistance may decrease due to semiconducting. .

Further, the total content of dysprosium (Dy) and terbium (Tb) is 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material.

By adjusting the total content of dysprosium (Dy) and terbium (Tb) to be 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material, insulation can be achieved. This makes it possible to improve reliability by increasing resistance.

c) Second subcomponent According to one embodiment of the present invention, the dielectric ceramic composition includes at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn as the second subcomponent. It can contain oxides or carbonates containing the above.

As the second subcomponent, the oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn is 0.1 mol per 100 mol of the base material powder. It can be included in a content of ~2.0 mol.

The second subcomponent serves to lower the firing temperature of the multilayer ceramic capacitor to which the dielectric ceramic composition is applied, and to improve the high-temperature withstand voltage characteristics.

The content of the above-mentioned second subcomponent and the content of the third to sixth subcomponents described later refer to the amount contained in 100 moles of the base material powder, and in particular, the content of the metal ions contained in each subcomponent. It can be defined as moles.

If the content of the second subcomponent is less than 0.1 mol, the firing temperature may become high and the high-temperature withstand voltage characteristics may deteriorate somewhat.

Moreover, when the content of the second subcomponent is 2.0 mol or more, the high temperature withstand voltage characteristics and the room temperature specific resistance may decrease.

In particular, the dielectric ceramic composition according to an embodiment of the present invention may include a second subcomponent having a content of 0.1 to 2.0 mol per 100 mol of the base material main component. Thereby, low temperature firing is possible and high high temperature withstand voltage characteristics can be obtained.

d) Third subcomponent According to one embodiment of the present invention, the dielectric ceramic composition includes a third subcomponent which is an oxide or carbonate containing Mg, which is a fixed-valence acceptor element. can be included.

The fixed-valence acceptor element Mg may contain 0.0 to 0.5 moles of a third subcomponent based on 100 moles of titanium (Ti) among the main components of the base material. .

The third subcomponent is a valence-fixed acceptor and a compound containing the same, and can act as an acceptor to reduce the electron concentration. By adding 0.0 to 0.5 mol of Mg, which is the fixed-valence acceptor element, which is the third subcomponent, to 100 mol of titanium (Ti) among the main components of the base material. , it is possible to maximize the effect of improving reliability by changing to n-type.

If the content of the third subcomponent exceeds 0.5 mol per 100 mol of the base material powder, there is a problem that the dielectric constant becomes low, which is not preferable.

However, according to one embodiment of the present invention, the third subcomponent is added in an amount of 0.5 mol per 100 mol of titanium (Ti) in order to maximize the effect of improving reliability due to n-type conversion. Although it is preferable to do so, it is not necessarily limited to this, and it may be added in an amount of 0.5 mol or less or a small amount exceeding 0.5 mol.

e) Fourth subcomponent According to one embodiment of the present invention, the dielectric ceramic composition may include a fourth subcomponent that is an oxide or carbonate containing Ba.

The dielectric ceramic composition may contain 0.0 to 4.15 moles of a fourth subcomponent, which is an oxide or carbonate containing Ba, per 100 moles of the base material main component.

The content of the fourth subcomponent can be based on the content of Ba element contained in the fourth subcomponent, without distinguishing between the addition forms such as oxides and carbonates.

The fourth subcomponent can play roles such as promoting sintering and adjusting the dielectric constant within the dielectric ceramic composition, and its content is 100 moles of the main component of the base material. On the other hand, if it exceeds 4.15 moles, there may be problems such as a low dielectric constant or a high firing temperature.

f) Fifth subcomponent According to one embodiment of the present invention, the dielectric ceramic composition includes one selected from the group consisting of oxides and carbonates of one or more elements of Ca and Zr. A fifth subcomponent including the above may be included.

The dielectric ceramic composition contains 0.0 to 20.0 moles of a fifth subcomponent, which is an oxide or carbonate containing at least one of Ca and Zr, per 100 moles of the base material main component. be able to.

The content of the fifth subcomponent is based on the content of at least one element among Ca and Zr contained in the fifth subcomponent, without distinguishing between the addition form such as oxide or carbonate. can do.

The fifth subcomponent plays a role of forming a core-shell structure in the dielectric ceramic composition to improve the dielectric constant and reliability, thereby adding more than 100 moles of the main component of the base material. On the other hand, when the content is 20.0 mol or less, a high dielectric constant is achieved and a dielectric ceramic composition with good high-temperature withstand voltage characteristics can be provided.

When the content of the fifth subcomponent exceeds 20.0 mol per 100 mol of the main component of the base material, the room temperature dielectric constant becomes low and the high temperature withstand voltage characteristics also deteriorate.

g) Sixth subcomponent According to one embodiment of the present invention, the dielectric ceramic composition includes, as the sixth subcomponent, an oxide containing at least one of Si and Al or a glass compound containing Si. can include.

The dielectric ceramic composition contains 0.0 mol of the sixth subcomponent, which is an oxide containing at least one of Si and Al, or a glass compound containing Si, per 100 moles of the main component of the base material. It can further contain up to 4.0 mol.

The content of the sixth subcomponent does not distinguish between the addition form such as glass, oxide, or carbonate, and the content of at least one element among Si and Al contained in the sixth subcomponent is determined. It can be used as a standard.

The sixth subcomponent serves to lower the firing temperature of the multilayer ceramic capacitor to which the dielectric ceramic composition is applied, and to improve the high-temperature withstand voltage characteristics.

If the content of the sixth subcomponent exceeds 4.0 mol per 100 mol of the main component of the base material, it is not preferable because it reduces sinterability and compactness and causes problems such as secondary phase formation. .

In particular, according to one embodiment of the present invention, the dielectric ceramic composition contains Al in a content of 4.0 mol or less, so that grain growth can be uniformly controlled, and the withstand voltage characteristics and reliability can be improved. This is effective in improving the DC-bias characteristics.

Hereinafter, the present invention will be explained in more detail by giving Examples and Comparative Examples, but these are intended to help concrete understanding of the invention, and the scope of the present invention is not limited by the Examples. .

(Example)
In an embodiment of the present invention, additives such as Dy, Tb, Al, Mg, and Mn, a binder, and an organic solvent such as ethanol are added to a dielectric raw material powder containing barium titanate (BaTiO ₃ ) powder, and wet mixing is performed. After providing a dielectric slurry, a dielectric layer can be formed by applying the dielectric slurry onto a carrier film and drying it to provide a ceramic green sheet.

At this time, the additives of all elements were monodispersed and added so that the size of the additives was 40% or less with respect to barium titanate.

In particular, the content of dysprosium (Dy) and terbium (Tb) among the rare earth elements added was 1.5 mol per 100 mol of titanium (Ti) among the main components of the base material.

Among the above examples, in Example 1, the content of dysprosium (Dy) and terbium (Tb) was 1.5 mol per 100 mol of titanium (Ti) among the main components of the base material, and in Example 2, , the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) was adjusted to be 0.15 or more and less than 0.5.

The ceramic green sheet can be produced by mixing ceramic powder, a binder, and a solvent to prepare a slurry, and then using the slurry by a doctor blade method to form a sheet having a thickness of several μm.

Next, a conductive paste for internal electrodes containing 40 to 50 parts by weight of nickel powder with an average particle size of 0.1 to 0.2 μm can be provided.

A conductive paste for the internal electrodes is applied onto the green sheets using a screen printing method to form internal electrodes, and the green sheets on which the internal electrode patterns are arranged are stacked to form a laminate. was crimped and cut.

Next, the cut laminate was heated to remove the binder, and then fired in a high temperature reducing atmosphere to form a ceramic body.

In the above firing process, after firing at a temperature of 1100 to 1200°C for 2 hours in a reducing atmosphere (0.1% H ₂ /99.9% N ₂ , H ₂ O / H ₂ /N ₂ atmosphere), It was oxidized and heat treated in a nitrogen (N ₂ ) atmosphere for 3 hours.

Next, the fired ceramic body was subjected to a termination process using copper (Cu) paste and an electrode firing process to complete an external electrode.

Further, the dielectric layer 111 inside the ceramic body 110 and the first and second internal electrodes 121 and 122 were manufactured so that the thickness after firing was 0.45 μm or less.

(Comparative example 1)
In Comparative Example 1, dysprosium (Dy) and terbium (Tb) were added so that the total content was 1.8 mol per 100 mol of titanium (Ti) among the main components of the base material, and other The manufacturing process is the same as in the embodiment described above.

(Comparative example 2)
In Comparative Example 2, dysprosium (Dy) and terbium (Tb) were added so that the total content was 2.1 mol per 100 mol of titanium (Ti) among the main components of the base material, and other The manufacturing process is the same as in the embodiment described above.

(Comparative example 3)
Comparative Example 3 is a conventional dielectric ceramic composition in which terbium (Tb) is not added and dysprosium (Dy) is added alone. The rest of the production process is the same as in the embodiment described above.

(Comparative example 4)
In Comparative Example 4, the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) was less than 0.15, and the other production steps were as follows. This is the same as in the embodiment described above.

(Comparative example 5)
In the case of Comparative Example 5, the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) was 0.5 or more, and the other The production process is the same as in the embodiment described above.

A temperature characteristic test and a HALT test were conducted on the prototype multilayer ceramic capacitor (Prototype MLCC) samples of Examples 1 and 2 and Comparative Examples 1 to 5 completed as described above to evaluate the defective rate.

The above temperature characteristic test measures the temperature coefficient of capacitance (TCC), and the X5R temperature characteristic is the capacitance ±15% in the range of -55°C to 85°C based on the 25°C capacity, and the X6S The temperature characteristics must satisfy the capacitance of ±22% in the range of -55°C to 105°C based on the 25°C capacity standard.

In the above HALT test, 40 multilayer ceramic capacitor (MLCC) chips were mounted on a substrate for each sample, and measurements were performed at 125° C. and 20 V (DC) for 12 hours.

Table 1 below shows the electrical characteristics of prototype multilayer ceramic capacitor (Proto-type MLCC) chips according to experimental examples (Examples 1 and 2 and Comparative Examples 1 and 2).

Referring to Table 1 above, in Comparative Examples 1 and 2, the total content of dysprosium (Dy) and terbium (Tb) exceeds 1.5 mol per 100 mol of titanium (Ti) among the main components of the base material. It can be seen that in some cases, not only the X6S temperature characteristics but also the X5R temperature characteristics are not satisfied.

In contrast, in Example 1 of the present invention, the total content of dysprosium (Dy) and terbium (Tb) was 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material. Therefore, it can be confirmed that not only the X6S temperature characteristics but also the X5R temperature characteristics are satisfied, and the reliability is also improved.

FIG. 3 is a graph showing the evaluation results of HALT tests according to Examples and Comparative Examples of the present invention.

Referring to FIG. 3, in case (a) according to Comparative Example 3 of the present invention, the composition is the same as that of the conventional dielectric ceramic composition, and terbium (Tb) is not added, and only dysprosium (Dy) is added. It was added alone. Here, it can be seen that the number of defective products after the HALT test was 5, indicating a high defective rate.

In addition, in case (b) according to Comparative Example 4 of the present invention, the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is less than 0.15. It can be seen that the number of defective products after the HALT test was 9, indicating a high defective rate.

This is thought to be due to the fact that the content of the terbium (Tb) added is small relative to the content of the dysprosium (Dy), and the reliability improvement effect of adding terbium (Tb) is small. .

On the other hand, in the case of Example 2 of the present invention (c), the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is 0.15 or more and 0.5 It can be confirmed that the number of defective items after the HALT test is 0, and the reliability is excellently improved.

On the other hand, in the case of Comparative Example 5 of the present invention (d), the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) was 0.5 or more. It was found that almost all samples had poor reliability.

When the ratio of the terbium (Tb) content to the dysprosium (Dy) content (Tb/Dy) is 0.50 or more, it is considered that insulation resistance decreases due to semiconductor formation.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations can be made without departing from the technical idea of the present invention as described in the claims. It is clear to a person of ordinary skill in the art that this is possible.

[Item 1]
Contains a BaTiO ₃ -based matrix main component and subcomponents,
The subcomponents include a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements,
A dielectric ceramic composition, wherein the ratio of the terbium (Tb) content to the trivalent lanthanum group rare earth element A content (Tb/A) satisfies 0.15≦Tb/A<0.50.
[Item 2]
The dielectric ceramic composition according to item 1, wherein the trivalent lanthanum group rare earth element A is dysprosium (Dy).
[Item 3]
Item 1 or 2, wherein the total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material. The dielectric ceramic composition described in .
[Item 4]
The dielectric ceramic composition contains at least one of Y, Ho, Er, Ce, Nd, Pm, Eu, Gd, Tm, Yb, Lu, and Sm based on 100 moles of the base material main component. The dielectric ceramic composition according to any one of items 1 to 3, further comprising 0.0 to 4.0 moles of a first subcomponent that is an oxide or carbonate.
[Item 5]
The dielectric ceramic composition is an oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn based on 100 moles of the base material main component. The dielectric ceramic composition according to any one of items 1 to 4, further comprising 0.1 to 2.0 moles of a second subcomponent.
[Item 6]
The dielectric ceramic composition contains 0.0 to 0.0 to 0.0 to 0.0 to 100 moles of titanium (Ti) as the main component of the base material, and a third subcomponent that is an oxide or carbonate containing Mg, which is a fixed valence acceptor element. The dielectric ceramic composition according to any one of items 1 to 5, further comprising 0.5 mol.
[Item 7]
The dielectric ceramic composition according to items 1 to 6 further contains 0.0 to 4.15 moles of a fourth subcomponent which is an oxide or carbonate containing Ba with respect to 100 moles of the base material main component. The dielectric ceramic composition according to any one of the items.
[Item 8]
The dielectric ceramic composition contains 0.0 to 20.0 moles of a fifth subcomponent, which is an oxide or carbonate containing at least one of Ca and Zr, per 100 moles of the base material main component. , the dielectric ceramic composition according to any one of items 1 to 7.
[Item 9]
The dielectric ceramic composition contains 0.0 mol of the sixth subcomponent, which is an oxide containing at least one of Si and Al, or a glass compound containing Si, with respect to 100 mol of the base material main component. The dielectric ceramic composition according to any one of items 1 to 8, further comprising ˜4.0 mol.
[Item 10]
a ceramic body including a dielectric layer, and a first internal electrode and a second internal electrode arranged to face each other with the dielectric layer interposed therebetween;
a first external electrode disposed outside the ceramic body and electrically connected to the first internal electrode; and a second external electrode electrically connected to the second internal electrode;
The dielectric layer includes a dielectric ceramic composition,
The dielectric ceramic composition includes a BaTiO ₃ base material main component and subcomponents,
The subcomponents include a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements,
A multilayer ceramic capacitor in which a ratio (Tb/A) of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A satisfies 0.15≦Tb/A<0.50.
[Item 11]
11. The multilayer ceramic capacitor according to item 10, wherein the trivalent lanthanum group rare earth element A is dysprosium (Dy).
[Item 12]
Item 10 or 11, wherein the total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material. The multilayer ceramic capacitor described in .
[Item 13]
The dielectric ceramic composition contains at least one of Y, Ho, Er, Ce, Nd, Pm, Eu, Gd, Tm, Yb, Lu, and Sm based on 100 moles of the base material main component. The multilayer ceramic capacitor according to any one of items 10 to 12, further comprising 0.0 to 4.0 mol of a first subcomponent that is an oxide or carbonate.
[Item 14]
The dielectric ceramic composition is an oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn based on 100 moles of the base material main component. The multilayer ceramic capacitor according to any one of items 10 to 13, further comprising 0.1 to 2.0 moles of a second subcomponent.
[Item 15]
The dielectric ceramic composition contains 0.0 to 0.0 to 0.0 to 0.0 to 100 moles of titanium (Ti) as the main component of the base material, and a third subcomponent that is an oxide or carbonate containing Mg, which is a fixed valence acceptor element. 15. The multilayer ceramic capacitor according to any one of items 10 to 14, further comprising 0.5 mol.
[Item 16]
The dielectric ceramic composition further contains 0.0 to 4.15 moles of a fourth subcomponent, which is an oxide or carbonate containing Ba, with respect to 100 moles of the main component of the base material, and contains 0.0 to 4.15 moles of a fourth subcomponent, which is an oxide or carbonate containing Ba, and The multilayer ceramic capacitor according to any one of items 10 to 15, further comprising 0.0 to 20.0 mol of a fifth subcomponent that is an oxide or carbonate containing at least one.
[Item 17]
The dielectric ceramic composition contains 0.0 mol of the sixth subcomponent, which is an oxide containing at least one of Si and Al, or a glass compound containing Si, with respect to 100 mol of the base material main component. The multilayer ceramic capacitor according to any one of items 10 to 16, further comprising ~4.0 mol.
[Item 18]
18. The multilayer ceramic capacitor according to any one of items 10 to 17, wherein the dielectric layer has a thickness of 0.45 μm or less, and the first and second internal electrodes have thicknesses of 0.45 μm or less.

110 Ceramic body 111 Dielectric layer 121 First internal electrode 122 Second internal electrode 131 First external electrode 132 Second external electrode

Claims (13)

Contains a BaTiO ₃ -based matrix main component and subcomponents,
The subcomponents include a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements,
The ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) satisfies 0.15≦Tb/A<0.50,
The trivalent lanthanum group rare earth element A is dysprosium (Dy),
The total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material,
the subcomponent does not contain Mg;
Dielectric porcelain composition. The dielectric ceramic composition contains at least one of Y, Ho, Er, Ce, Nd, Pm, Eu, Gd, Tm, Yb, Lu, and Sm based on 100 moles of the base material main component. The dielectric ceramic composition according to claim 1, further comprising 0.0 to 4.0 moles of the first subcomponent which is an oxide or carbonate. The dielectric ceramic composition is an oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn based on 100 moles of the base material main component. The dielectric ceramic composition according to claim 1 or 2, further comprising 0.1 to 2.0 moles of a second subcomponent. Claims 1 to 3, wherein the dielectric ceramic composition further contains 0.0 to 4.15 moles of a fourth subcomponent which is an oxide or carbonate containing Ba with respect to 100 moles of the base material main component. The dielectric ceramic composition according to any one of . The dielectric ceramic composition contains 0.0 to 20.0 moles of a fifth subcomponent, which is an oxide or carbonate containing at least one of Ca and Zr, per 100 moles of the base material main component. , The dielectric ceramic composition according to any one of claims 1 to 4. The dielectric ceramic composition contains 0.0 mol of the sixth subcomponent, which is an oxide containing at least one of Si and Al, or a glass compound containing Si, with respect to 100 mol of the base material main component. The dielectric ceramic composition according to any one of claims 1 to 5, further comprising ˜4.0 mol. a ceramic body including a dielectric layer, and a first internal electrode and a second internal electrode arranged to face each other with the dielectric layer interposed therebetween;
a first external electrode disposed outside the ceramic body and electrically connected to the first internal electrode; and a second external electrode electrically connected to the second internal electrode;
The dielectric layer includes a dielectric ceramic composition,
The dielectric ceramic composition includes a BaTiO ₃ base material main component and subcomponents,
The subcomponents include a trivalent lanthanum group rare earth element A and terbium (Tb) as rare earth elements,
The ratio of the content of terbium (Tb) to the content of the trivalent lanthanum group rare earth element A (Tb/A) satisfies 0.15≦Tb/A<0.50,
The trivalent lanthanum group rare earth element A is dysprosium (Dy),
The total content of the trivalent lanthanum group rare earth element A and terbium (Tb) is 0.2 mol or more and 1.5 mol or less per 100 mol of titanium (Ti) among the main components of the base material,
the subcomponent does not contain Mg;
Multilayer ceramic capacitor. The dielectric ceramic composition contains at least one of Y, Ho, Er, Ce, Nd, Pm, Eu, Gd, Tm, Yb, Lu, and Sm based on 100 moles of the base material main component. The multilayer ceramic capacitor according to claim 7, further comprising 0.0 to 4.0 moles of the first subcomponent which is an oxide or carbonate. The dielectric ceramic composition is an oxide or carbonate containing at least one of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn based on 100 moles of the base material main component. The multilayer ceramic capacitor according to claim 7 or 8, further comprising 0.1 to 2.0 moles of a second subcomponent. Claims 7 to 9, wherein the dielectric ceramic composition further contains 0.0 to 4.15 moles of a fourth subcomponent which is an oxide or carbonate containing Ba, based on 100 moles of the base material main component. The multilayer ceramic capacitor according to any one of the above. The dielectric ceramic composition further contains 0.0 to 20.0 moles of a fifth subcomponent which is an oxide or carbonate containing at least one of Ca and Zr. The multilayer ceramic capacitor described in . The dielectric ceramic composition contains 0.0 mol of the sixth subcomponent, which is an oxide containing at least one of Si and Al, or a glass compound containing Si, with respect to 100 mol of the base material main component. The multilayer ceramic capacitor according to any one of claims 7 to 11, further comprising ~4.0 mol. 13. The dielectric layer according to claim 7, wherein the dielectric layer has a thickness of 0.45 μm or less, and the first internal electrode and the second internal electrode have a thickness of 0.45 μm or less. Multilayer ceramic capacitor.