KR101912262B1 - Multilayer Ceramic Capacitor and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a multilayer ceramic electronic component and a method of manufacturing the same, and is characterized in that conductive particles are dispersed in a ceramic body to increase a dielectric constant. According to the present invention, a multilayer ceramic electronic component having increased dielectric constant and increased capacitance can be obtained.

Description

TECHNICAL FIELD [0001] The present invention relates to a multilayer ceramic electronic component,

The present invention relates to a multilayer ceramic electronic component and a method of manufacturing the same, and more particularly, to a multilayer ceramic electronic component whose capacity has been increased due to an improvement in dielectric constant and a manufacturing method thereof.

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 capacity, and ease of mounting.

In recent years, miniaturization and multifunctionalization of electronic products have led to the tendency of miniaturization and high functionality of chip components. Therefore, a multilayer ceramic capacitor is required to have a small-sized and large-capacity high-capacity product.

In order to increase the capacity of the multilayer ceramic capacitor, the thickness of the dielectric layer and the internal electrode layer must be made thinner and the number of stacked layers must be increased.

However, as dielectric layers and internal electrodes are thinned and the number of stacked layers increases, the possibility of dielectric breakdown increases, delamination and cracks occur, and reliability of the multilayer ceramic capacitor may be reduced .

As a result, miniaturization and high capacity of the multilayer ceramic capacitor are limited.

An object of the present invention is to provide a multilayer ceramic electronic device having increased capacitance due to an increase in dielectric constant and a method of manufacturing the same.

A multilayer ceramic electronic component according to an embodiment of the present invention includes: a ceramic body in which conductive particles are dispersed; And an inner electrode laminated inside the ceramic body.

The ratio of the volume of the conductive particles to the volume of the ceramic body may be 4 or more and 6 or less.

The ceramic body may have barium titanate.

The conductive particles may be conductive metal particles, and the conductive metal may include at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.

The conductive particles may be a conductive oxide, and the conductive oxide may be indium-tin oxide or ruthenium oxide.

In another aspect of the present invention, there is provided a method of manufacturing a multilayer ceramic electronic device, comprising: weighing the ceramic powder and the conductive powder so that the ratio of the volume of the conductive powder to the volume of the ceramic powder is 4 or more and 6 or less; Adding an organic solvent, a binder, and the like to the mixture of the ceramic powder and the conductive powder; and ball milling the mixture to prepare a ceramic slurry.

The method may further include preparing a ceramic green sheet using the ceramic slurry after the step of preparing the ceramic slurry, and laminating the ceramic green sheet.

The ceramic powder may include barium titanate.

The conductive powder may be a conductive metal powder, and the conductive metal may include at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.

The conductive powder may be a conductive oxide powder, and the conductive oxide may be indium-tin oxide or ruthenium oxide.

According to the present invention, a multilayer ceramic electronic component having increased dielectric constant and increased capacitance can be obtained.

1 is a perspective view of a multilayer ceramic electronic component according to an embodiment of the present invention.
2 is a cross-sectional view taken along line XX 'of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

1 is a perspective view of a multilayer ceramic electronic component according to an embodiment of the present invention.

The multilayer ceramic electronic component may include a multilayer ceramic capacitor, a chip inductor, and a chip bead. Herein, the present invention is described in detail by taking a multilayer ceramic capacitor as an example, but the present invention is not limited thereto.

The multilayer ceramic electronic component according to the present embodiment may include a ceramic body 10, external electrodes 21 and 22 formed outside the ceramic body, and internal electrodes 31 and 32 formed inside the ceramic body.

Referring to FIG. 1, the ceramic body 10 may be a rectangular parallelepiped. The direction in which the first and second external electrodes 21 and 22 are connected is referred to as a longitudinal direction and the direction in which the internal electrodes 31 and 32 are laminated is referred to as a ' The direction perpendicular to the stacking direction can be referred to as a " width direction ".

The ceramic body 10 may have a length greater than the width and the thickness, and the width and the thickness may be the same.

In the ceramic body 10, the conductive particles 30 may be dispersed therein.

Ceramic body The ceramic body 10 can be made of a ceramic material having a high dielectric constant, but not limited thereto, a barium titanate (BaTiO3) material, a strontium titanate (SrTiO3) material, or the like can be used.

The ceramic body 10 is obtained by laminating a plurality of ceramic layers and then sintering them, and adjacent dielectric layers may be integrated to such an extent that boundaries can not be confirmed.

The conductive particles refer to electrically conductive particles, and the conductive particles may be conductive metal particles or conductive oxide particles.

The conductive metal particles may include at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.

The conductive metal is not limited thereto and may be a metal having electrical conductivity.

The conductive metal may possibly not react with the ceramic dielectric layer and thus be highly stable. Most of the metal powders have an oxide film formed on the surface of the oxide and have high stability. It is sufficient if it is not an oxide of a highly reactive metal such as an alkali metal or the like.

For example, nickel used as a material for internal electrodes is known not to react with dielectric powder.

The conductive oxide particle refers to an oxide having electrical conductivity among the oxides.

The conductive oxide may be indium-tin oxide or ruthenium oxide. Specifically, _{RuO 2, IrO 2, ReO 3} , SrVO 3, SrRuO 3, SrMoO 3, CaRuO 3, BaRuO 3, PbRuO 3, BiRuO 3, LaTaO 3, may be a Bi ₂ Ru ₂ O _7.

The reason why the conductive oxide is electrically conductive is that the oxygen vacancy is present in the oxide. The energy vacancy is present in the band gap due to the oxygen vacancy formed in the oxide, and the oxide becomes electrically conductive by the hopping phenomenon You can.

The ratio of the volume of the conductive particles to the volume of the ceramic body may be 4 or more and 6 or less.

When the ratio of the volume of the conductive particles to the volume of the ceramic body is less than 4, the increase in the dielectric constant of the ceramic body is insignificant and the increase in the capacitance of the multilayer ceramic electronic component is also insignificant.

On the other hand, when the ratio of the volume of the conductive particles to the volume of the ceramic body exceeds 6, the distance between the conductive particles becomes narrow, and consequently electrical conduction may occur due to the conductive particles. Can be degraded.

The ratio of the volume occupied by the conductive particles to the volume of the ceramic body can be an important factor because the conductive particles can be connected to form a new conductive path.

When the conductive particles are added to the ceramic body, the dielectric constant of the ceramic body may increase.

In the case of dispersing the metal powder in the dielectric layer, the metal powder may serve as a catalyst promoting the decomposition of the binder in the sintering accelerator or the calcining step during the calcination process.

Particularly, when the metal powder is partially dispersed in the dielectric layer, the dielectric constant of the dielectric layer is increased. Due to the effect of increasing the dielectric constant, the number of stacked internal electrodes can be reduced during the design of the capacitor product, thereby greatly reducing the cost burden.

The conductive particles dispersed in the dielectric layer can partially perform the role of the internal electrode.

The external electrodes 21 and 22 may be formed on the outer surface of the ceramic body 10.

The external electrodes 21 and 22 are formed using a conductive paste including a conductive metal and a glass frit, but the conductive metal may be formed of copper, a copper alloy, nickel, a nickel alloy, silver, palladium, have.

The external electrodes 21 and 22 may be formed on both sides of the ceramic body 10. At this time, the external electrodes 21 and 22 may be connected to the internal electrodes 31 and 32 exposed on one surface of the ceramic body 10.

The internal electrodes 31 and 32 may be stacked in the ceramic body 10.

The internal electrodes 31 and 32 may be formed such that one end of the internal electrodes 31 and 32 is exposed on one side of the ceramic body 10. If one end of one internal electrode 31 is formed to be exposed on one side of the ceramic body 10, one end of the neighboring internal electrode 32 may be exposed on the opposite side of the ceramic body 10 .

The internal electrodes 31 and 32 may be formed by printing a paste containing a conductive metal, a binder and a solvent on a dielectric green sheet and firing the same. As the conductive metal, nickel (Ni), nickel alloy, or the like can be used. The conductive paste composition for the internal electrode may further include a ceramic material, for example, barium titanate. As the binder, a polymer resin such as polyvinyl butyral or ethyl cellulose can be used. The solvent for the conductive paste for the internal electrode is not particularly limited, and for example, terpineol, dihydroterpineol, butyl carbitol, kerosene and the like can be used.

The internal electrodes 31 and 32 may be formed on the dielectric green sheet by a method such as screen printing or gravure printing.

In another aspect of the present invention, there is provided a method of manufacturing a multilayer ceramic electronic device, comprising: weighing the ceramic powder and the conductive powder so that the ratio of the volume of the conductive powder to the volume of the ceramic powder is 4 or more and 6 or less; Adding an organic solvent, a binder, and the like to the mixture of the ceramic powder and the conductive powder; and ball milling the mixture to prepare a ceramic slurry.

The method may further include preparing a ceramic green sheet using the ceramic slurry after the step of preparing the ceramic slurry, and laminating the ceramic green sheet.

In order to evenly disperse the conductive powder in the ceramic body, the ceramic powder and the conductive powder are weighed so as to have a volume ratio of 4 or more and 6 or less, and then other additives such as an organic solvent, a binder and a plasticizer are added thereto, and ceramic balls such as alumina or zirconia To perform a three-roll ball milling process to produce a ceramic slurry.

A ceramic slurry in which a conductive powder is uniformly dispersed is coated on a carrier film made of a polymer resin through a doctor blade method and then dried to prepare a green sheet and laminated to form a laminate type capacitor have.

However, the present invention is not limited thereto, and a capacitor of a bulk type may be manufactured instead of a capacitor of a stacked type, depending on the characteristics of a desired product.

The ceramic powder may include barium titanate.

The conductive powder may be a conductive metal powder, and the conductive metal may include at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.

The conductive powder may be a conductive oxide powder, and the conductive oxide may be indium-tin oxide or ruthenium oxide.

In this embodiment, matters relating to the ceramic powder, the conductive metal, and the conductive oxide are the same as those described above.

[Example]

A multilayer ceramic capacitor was prepared by the following method.

First, a ceramic slurry in which barium titanate powder is mixed with additives such as a binder and a binder is ball milled to prepare a ceramic slurry in which the ceramic powder is evenly dispersed. A ceramic slurry is coated on the carrier film using a doctor blade method and dried, .

The dielectric powder used was barium titanate having an average particle size of 300 nanometers and indium tin oxide (ITO) having an average particle size of 180 nanometers as the conductive particles.

1%, 2.5%, 5%, and 10% of the volume of the conductive particles with respect to the ceramic body.

Next, an additive such as a solvent and a binder was added to the ITO powder and ball milled to prepare a ceramic slurry in which ITO was evenly dispersed. A ceramic slurry was applied on a polyethylene film through a doctor blade method and dried to prepare a ceramic green sheet.

Next, an internal electrode is formed on the ceramic green sheet by a paste method using nickel as a main component by screen printing, a green sheet is laminated to form a laminate, and the laminate is dried at 85 to 1,000 kgf / Lt; 2 >, and then the laminate was cut to prepare a green chip.

The green chip was dipped in an external electrode paste and dried to form an external electrode on the external surface of the green chip.

The green chip having the external electrode formed thereon was subjected to a binder removal process in which the green chip was maintained at 230 DEG C for 60 hours in an atmospheric environment and then fired in an atmospheric environment at 1200 DEG C to simultaneously fuse the internal electrode and the external electrode.

Through this process, a multilayer ceramic capacitor in which ITO, which is a conductive oxide, was uniformly dispersed in a ceramic body was prepared.

Table 1 shows the results of measurement of dielectric constant, capacitance, and insulation resistance while varying the ratio of the volume occupied by conductive particles (ITO) in the volume of the ceramic body.

Barium titanate ITO Volume ratio (%) of conductive particles to ceramic body permittivity Capacitance
(uF) size
(nm) volume
(vol%) size
(nm) volume
(vol%) Comparative Example 1 * 300 100 - - 0 3300 10.0 Comparative Example 2 * 300 99 180 One One 3350 10.1 Comparative Example 3 * 300 97.5 180 2.5 2.5 3430 10.7 Example 1 300 95 180 5 5 3900 12.4 Comparative Example 4 * 300 90 180 10 10 4700 16.5

*: Not within the scope of the present invention.

Referring to Table 1, Comparative Example 1 shows a case where a conductive oxide (ITO) is not added to the ceramic body. The dielectric constant is 3300 and the capacitance is 10.0 uF. In Comparative Example 2, the volume ratio of ITO is 1% 3350, the capacitance is 10.1, and the volume ratio of ITO in the comparative example 3 is 2.5%. The dielectric constant is 3430 and the capacitance is 10.7.

In Example 3, the volume ratio of ITO to the ceramic body is 5%, and the dielectric constant is 3900 and the capacitance is 12.4 uF.

In Comparative Example 4, the volume ratio of ITO to the ceramic body was 10%, and the dielectric constant was 4700 and the capacitance was 16.5.

According to Table 1, it can be seen that as the content of ITO increases, the dielectric constant and the capacitance increase.

In particular, it can be seen that the dielectric constant and the capacitance increase sharply in Example 3 in which the volume ratio of ITO is 5%.

In the case of Comparative Example 4, although the dielectric constant and the capacitance have a considerably large value, they do not fall within the scope of the present invention. The reason for this is that as the volume occupied by the ITO increases, the interval between the ITO particles becomes shorter and the insulation resistance of the ceramic body decreases.

The present invention is not limited to the above-described embodiments and the accompanying drawings, but is intended to be limited only by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

10: Ceramic body
21, 22: second external electrode
30: conductive particles
31, 32: internal electrode

Claims (14)

A ceramic body in which conductive particles are dispersed; And
An inner electrode laminated and disposed inside the ceramic body;
Wherein the conductive particles are conductive oxides, and the conductive oxide is indium-tin oxide.
The method according to claim 1,
Wherein the ratio of the volume of the conductive particles to the volume of the ceramic body is 4 or more and 6 or less.
The method according to claim 1,
Wherein the ceramic body includes barium titanate.
The method according to claim 1,
Wherein the conductive particles are conductive metal particles.
5. The method of claim 4,
Wherein the conductive metal comprises at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.
delete delete Weighing the ceramic powder and the conductive powder such that the ratio of the volume of the conductive powder to the volume of the ceramic powder is 4 or more and 6 or less;
Adding an organic solvent, a binder or the like to the mixture of the ceramic powder and the conductive powder; and
Ball milling the mixture to prepare a ceramic slurry;
Wherein the conductive powder is a conductive oxide powder, and the conductive oxide is indium-tin oxide.
9. The method of claim 8,
Further comprising a step of preparing a ceramic green sheet using the ceramic slurry after the step of preparing the ceramic slurry, and laminating the ceramic green sheet.
9. The method of claim 8,
Wherein the ceramic powder comprises barium titanate.
9. The method of claim 8,
Wherein the conductive powder is a conductive metal powder.
12. The method of claim 11,
Wherein the conductive metal comprises at least one selected from the group consisting of nickel, copper, titanium, vanadium, zinc, and alloys thereof.
delete delete

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