KR101275446B1 - Conductive paste composition for internal electrode and fabricating method of multilayered ceramic electronic component using the same - Google Patents

Abstract

PURPOSE: A conductive paste composite for an internal electrode for a laminated ceramic electronic component using the same and a manufacturing method thereof are provided to improve the connective property of the internal electrode, thereby increasing the capacity of the component. CONSTITUTION: A conductive paste composite for an internal electrode includes powder material and a conductive metal(40). The powder material has a first powder material and a second powder material(60). The average particle size of the first powder material is 10nm. The average particle size of the second powder material is 20nm. A weight ratio between the first and the second powder material is 90:10 to 70:30. The average particle size of the conductive metal is 50 to 150nm.

Description

Conductive paste composition for internal electrode and fabricating method of multilayered ceramic electronic component using the same}

The present invention relates to a conductive paste composition for internal electrodes and a method of manufacturing a multilayer ceramic electronic component using the same. More specifically, the present invention relates to a conductive paste composition for internal electrodes capable of increasing connectivity and capacity of internal electrodes, and a method of manufacturing a multilayer ceramic electronic component using the same.

Since the internal electrodes of the multilayer ceramic capacitor are made of metal, the sintering temperature is lower than that of the dielectric body made of ceramic. Therefore, during sintering, the inner electrode may shrink more quickly, which may cause delamination and cracking between the inner electrode and the dielectric. In addition, the connectivity of the internal electrodes is reduced, which may cause problems in the implementation of the capacitance.

After firing, common materials are used to control the sintering shrinkage of the nickel powder used as the conductive metal to secure the excellent electrode connectivity of the internal electrodes of the multilayer ceramic capacitor and to secure the capacity.

However, since the common powder is a kind of impurity from the viewpoint of the electrode, a minimum amount should be added within a limit that can suppress the difference in plastic behavior with the dielectric layer. Therefore, the amount of common materials may be insufficient to fill the pores between the relatively large and high content of the metal powder.

This problem may occur in both the inside and the surface of the internal electrode, and the surface of the dried internal electrode becomes rough due to the non-uniform distribution of the common powder, which may eventually cause local breakage and agglomeration of the internal electrode during firing.

As a result, the electrode expansion in the thickness direction of the multilayer ceramic capacitor is increased, the electrode connectivity is also lowered, and the electrical characteristics and the withstand voltage characteristics may be deteriorated.

The present invention is to provide a conductive paste composition for an internal electrode that can increase the connectivity and capacity of the internal electrode and a method of manufacturing a multilayer ceramic electronic component using the same.

One aspect of the invention is a conductive metal; And a common material comprising a first common material having an average particle diameter of 10 nm and a second common material having an average particle diameter of 20 nm.

In one embodiment, the average particle diameter of the conductive metal may be 50 to 150 nm.

In one embodiment, the conductive metal may include nickel.

In one embodiment, the content of the common material may be 5 to 15 parts by weight based on 100 parts by weight of the conductive metal.

In one embodiment, the weight ratio of the first and second common materials may be 90 to 10 to 70 to 30.

In one embodiment, the common material may comprise a ceramic material.

In one embodiment, the ceramic material may comprise barium titanate.

In one embodiment, the first and the second common material may be the same material.

Another aspect of the invention provides a method for preparing a ceramic green sheet; Providing a conductive paste composition comprising a conductive metal and a common material including a first common material having an average particle diameter of 10 nm and a second common material having an average particle diameter of 20 nm; And forming an internal electrode on the ceramic green sheet by using the conductive paste composition.

In one embodiment, the average particle diameter of the conductive metal may be 50 to 150 nm.

In one embodiment, the conductive metal may include nickel.

In one embodiment, the content of the common material may be 5 to 15 parts by weight based on 100 parts by weight of the conductive metal.

In one embodiment, the weight ratio of the first and second common materials may be 90 to 10 to 70 to 30.

In one embodiment, the common material may comprise a ceramic material.

In one embodiment, the ceramic material may comprise barium titanate.

In one embodiment, the first and the second common material may be the same material.

According to the present invention, a conductive paste composition for internal electrodes capable of increasing electrode connectivity and capacity can be obtained, and a multilayer ceramic electronic component having increased electrode connectivity and capacity can be obtained.

1 is a perspective view of a multilayer ceramic capacitor manufactured using a conductive paste composition for internal electrodes according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line XX 'of FIG. 1.
3 is an enlarged view of a portion Z of FIG. 2.
It is a schematic diagram of the electrically conductive paste composition for internal electrodes which concerns on one Embodiment of this invention.

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

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.

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

The shape and the size of the elements in the drawings may be exaggerated for clarity and the same elements are denoted by the same reference numerals in the drawings.

The multilayer ceramic electronic component includes a multilayer ceramic capacitor, a chip inductor, a chip bead, a chip varistor, and the like. In the present embodiment, the multilayer ceramic capacitor is described as an example.

1 is a perspective view of a multilayer ceramic capacitor manufactured using a conductive paste composition for internal electrodes according to an embodiment of the present invention. 2 is a cross-sectional view taken along line XX ′ of FIG. 1. 3 is an enlarged view of a portion Z of FIG. 2. It is a schematic diagram of the electrically conductive paste composition for internal electrodes which concerns on one Embodiment of this invention.

1 to 2, the multilayer ceramic capacitor manufactured using the conductive paste composition for the internal electrode according to the exemplary embodiment of the present invention may include a ceramic body 10 and an external electrode formed on the outside of the ceramic body 10. 21 and 22 and internal electrodes 31 and 32 stacked in the ceramic body 10 may be included.

The ceramic body 10 may have a rectangular parallelepiped shape. The “L direction” of the ceramic body may be referred to as the “length direction”, the “W direction” as the “width direction”, and the “T direction” as the “thickness direction”.

The ceramic body 10 may be made of a ceramic material having a high dielectric constant. The ceramic material may be, but is not limited to, barium titanate or strontium titanate.

The ceramic body 10 is obtained by stacking a plurality of ceramic dielectric layers 11 and then sintering them. The adjacent dielectric layers 11 may be integrated to such an extent that their boundaries cannot be identified.

The external electrodes 21 and 22 may be formed at both side surfaces of the ceramic body 10 in the longitudinal direction. In this case, the external electrodes 21 and 22 may be electrically connected to the internal electrodes 31 and 32 formed to be exposed on one surface of the ceramic body 10.

The external electrodes 21 and 22 may be formed using a conductive paste composition including a conductive metal and glass frit, but are not limited thereto, and the conductive metal may be copper, a copper alloy, nickel, a nickel alloy, silver, palladium, or the like. Can be made.

The internal electrodes 31 and 32 may be formed by printing the conductive paste composition for the internal electrodes on a ceramic green sheet. Specifically, the internal electrode may be formed on the ceramic green sheet using a method such as screen printing or gravure printing.

Referring to FIG. 3, the conductive paste composition for the internal electrode may include a conductive metal 40, a binder (not shown), and an organic solvent (not shown).

The conductive metal 40 is sufficient as long as it can impart conductivity to the internal electrodes 31 and 32. Specifically, the conductive metal 40 may include one or more selected from the group consisting of nickel, copper, palladium, and alloys thereof. The average particle diameter of the conductive metal may be 50 to 150 nm.

Polymer binders, such as polyvinyl butyral and ethyl cellulose, can be used as a binder. The organic solvent is not particularly limited, and for example, terpineol, dihydroterpineol, butyl carbitol, kerosine and the like can be used.

The conductive paste composition for the internal electrode may further include the common materials 50 and 60. The common materials 50 and 60 may be ceramic powder particles, specifically, barium titanate powder.

The reason for adding the common materials 50 and 60 to the paste composition for internal electrodes is as follows.

First, when the sintering start temperature of the conductive metal 60 is reached, the surface atoms of the conductive metal particles 40 that are in contact with each other due to sufficient thermal energy may move, so that atoms on the surface of the conductive metal particles 60 may be formed of conductive metal particles ( 60 may move to a portion in contact with each other so that the contact portion may be widened.

This is called necking, and the reason for this phenomenon is to reduce the overall surface energy by reducing the surface area of the conductive metal particles 60. To reduce the surface energy can be the driving force of sintering.

When the common materials 50 and 60 are added to the conductive paste composition, the probability that the common materials 50 and 60 are present between the conductive metal particles 40 may increase. As long as the common materials 50 and 60 exist between the conductive metal particles 40, the probability of contact between the conductive metal particles 40 may be reduced, and thus the probability of occurrence of necking may be reduced.

As a result, the effect of delaying the sintering of the conductive metal can be obtained, and eventually, the effect of raising the sintering start temperature can be obtained.

The common material may include first and second common materials 50 and 60, and the first and second common materials 50 and 60 may have different sizes of particles. The average particle diameter of the second common material 60 may be larger than the average particle diameter of the first common material 50, and specifically, the average particle diameter of the first common material 50 may be 10 nm, and the average particle diameter of the second common material 60 may be sufficient as that. May be 20 nm.

The reason why the first and second common materials 50 and 60 having different average particle diameters are mixed and used is that the filling rate is higher when large and small particles are used together compared to the case where only the particles of the same size are filled.

By mixing the first and second common materials 50 and 60 having different sizes together and using them as the common materials, more common materials 50 and 60 can be disposed between the conductive metal particles 40, which causes the conductive metal particles to be disposed. 40 can maximize the effect of delaying the inter-sintering.

The first and second common materials 50, 60 may be the same material. That is, both the first and second common materials 50 and 60 may be barium titanate.

In the case where the first and second common materials 50 and 60 are the same material, physical properties of the first and second common materials 50 and 60 may be similar, and thus may be easier to control the sintering characteristics and the microstructure. In addition, a separate process of preparing other materials can be omitted, thereby reducing the process cost.

The content of the common materials 50 and 60 may be 5 to 15 parts by weight based on 100 parts by weight of the conductive metal.

The weight ratio of the first and second common materials 50 and 60 may be 70 to 30 to 90 to 10.

When the weight ratio of the first common material 50 is less than 70 (when the weight ratio of the second common material 60 is more than 30) and when the weight ratio of the first common material 50 is greater than 90 (the weight ratio of the second common material 60) Is less than 10), the probability that the common material exists between the conductive metal particles 40 may decrease.

The effect of delaying sintering between the conductive metal particles 40 may be insignificant.

The internal electrodes 31 and 32 may be sintered at a relatively lower temperature than the ceramic body 10. Since the sintering temperature difference between the ceramic body 10 and the internal electrodes 31 and 32 is large, the surface of the internal electrodes 31 and 32 may be rougher due to the sintering shrinkage of the internal electrodes 31 and 32. In addition, the connectivity and capacity of the internal electrodes 31 and 32 may be reduced.

That is, by mixing and adding two common materials 50 and 60 having a smaller particle size than the conductive metal particles 40 and having different particle sizes at a predetermined ratio, the contact between the conductive metal particles 4 is limited to the conductive metal particles ( 40) can increase the degree of dispersion. As a result, the plastic shrinkage of the internal electrodes can be delayed during firing, and consequently, the sintering shrinkage of the internal electrodes 31 and 32 can be suppressed.

The common materials 50 and 60 can use the same main component as barium titanate used as the dielectric of the multilayer ceramic capacitor. The common materials 50 and 60 may be absorbed into the dielectric layer after firing and finally contribute to the dielectric properties. It is therefore desirable to have the same or similar composition as the barium titanate used for the dielectric layer.

Another aspect of the invention provides a method for preparing a ceramic green sheet; Providing a conductive paste composition comprising a conductive metal and a common material including a first common material having an average particle diameter of 10 nm and a second common material having an average particle diameter of 20 nm; And forming an internal electrode on the ceramic green sheet by using the conductive paste composition.

First, the ceramic green sheet may be ball milled by mixing a ceramic powder having a high dielectric constant with an organic solvent, a binder, and the like to prepare a ceramic slurry, and then the ceramic green sheet may be manufactured from the ceramic slurry through a method such as a doctor blade.

The high dielectric constant ceramic powder may include barium titanate, strontium titanate, or the like.

Next, the electrically conductive paste composition containing the electrically conductive metal and the common material containing the 1st common material whose average particle diameter is 10 nm, and the 2nd common material whose average particle diameter is 20 nm can be provided.

The average particle diameter of the conductive metal may be 50 ~ 150nm.

The conductive metal may include nickel.

The content of the common material may be 5 to 15 parts by weight based on 100 parts by weight of the conductive metal.

The weight ratio of the first and second common materials may be 90 to 10 to 70 to 30.

The common material may comprise a ceramic material, and the ceramic material may include barium titanate.

The first and second common materials may be the same material.

Next, an internal electrode may be formed on the ceramic green sheet using the conductive paste composition.

Next, after laminating a ceramic green sheet on which internal electrodes are formed, the multilayer ceramic electronic component may be manufactured by pressing, cutting, sintering, and external electrodes.

Matters relating to the conductive metal, the first and second common materials, and the like may be the same as those described in the above embodiments.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

The multilayer ceramic capacitor according to the embodiment was prepared as follows.

First, ceramic green sheets were manufactured using barium titanate.

Next, after mixing a polyvinyl butyral with ethanol and a binder as an organic solvent to a nickel metal powder having an average particle diameter of 100 nm, a barium titanate powder having an average particle diameter of 10 nm, and a barium titanate powder having an average particle diameter of 20 nm, ball-milling was performed. To prepare a conductive paste composition.

Nickel was 50% by weight based on the total weight of the conductive paste composition.

In addition, 10 parts by weight of barium titanate was added to 100 parts by weight of nickel.

The barium titanate is a mixture of barium titanate powder having an average particle diameter of 10 nm and barium titanate powder having an average particle diameter of 20 nm, and the weight ratio thereof was changed from 0: 100 to 100: 0.

Next, the conductive paste composition was printed on a ceramic green sheet to form an internal electrode, and the laminate was formed to form a ceramic green laminate, and then the ceramic green laminate was pressure-pressed at 1000 kgf / cm ² at 85 ° C.

Next, the pressed ceramic laminates were cut in the form of individual chips, and the cut chips were kept at 230 ° C. for 60 hours in an air atmosphere to proceed with a binder removal. Thereafter, at 950 ° C., the internal electrode was calcined under an oxygen partial pressure of 10 ⁻¹¹ to 10 ⁻¹⁰ atm lower than the Ni / NiO equilibrium oxygen partial pressure.

After the outer surface of the fired chip was polished, the fired chip was dipped in the conductive paste composition for external electrodes and then baked to form an external electrode. The electrically conductive paste composition for external electrodes was manufactured by adding glass, a binder, etc. to copper powder. On the external electrode surface, a tin plating layer was formed by electroplating.

After printing the electrically conductive paste composition for internal electrodes on the ceramic green sheet, the dry film density was measured. The dry film density was measured by the Archimenes method.

After measuring the capacitance of the finished multilayer ceramic capacitor, the surface roughness (Ra) of the internal electrode and the connectivity of the electrode were measured based on the electron scanning micrograph of the polished cut surface.

Table 1 shows the results of measuring surface roughness (Ra), dry film density, electrode connectivity, and capacitance.

division BT content Surface roughness
(Ra, 占 퐉) Dry film density
(g / cm3) Electrode Connectivity
(%) Volume
(㎌) 20nm BT
(weight%) 10nm BT
(weight%) Comparative Example 1 100 0 0.019 5.61 88.2 1.65 Comparative Example 2 90 10 0.017 5.63 92.4 1.75 Comparative Example 3 70 30 0.017 5.64 94.5 1.74 Comparative Example 4 50 50 0.013 5.67 97.0 1.86 Example 1 30 70 0.012 5.7 99.0 2.00 2 to implementation 10 90 0.012 5.71 99.1 2.01 Comparative Example 5 0 100 0.014 5.69 98.6 1.97

Referring to Table 1, Examples 1 and 2 are 10 and 10 wt% BT powder, respectively, the surface roughness (Ra) is both 0.012㎛, dry film density is 5.7, 5.71 g / cm3, respectively, The electrode connectivity is 99.0 and 99.1%, respectively, and the capacities are 2.00 and 2.01㎌, respectively. BT represents barium titanate.

Comparative Example 1 is a case where only 20nm BT powder is added, Comparative Examples 2 to 3 are 10, 30, 50% by weight of 10nm BT powder, respectively, the surface roughness (Ra) is increased as the content of 10nm BT powder increases It can be seen that the dry film density increases, the electrode connectivity increases, and the capacity also increases.

When the 10 nm BT powder is 70 and 90 wt% (Examples 1 and 2), the values of electrode connectivity and capacity indicate the maximum values.

In Comparative Example 5, only 10 nm BT powder was added, and surface roughness, dry film density, electrode connectivity, and capacity were all reduced.

The terms used in the present invention are intended to illustrate specific embodiments and are not intended to limit the invention. The singular presentation should be understood to include plural meanings, unless the context clearly indicates otherwise.

Terms such as "include" or "have" mean that there is a feature, number, step, operation, component, or combination thereof described on the specification, but not intended to exclude it.

The present invention is not limited by 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: external electrode
31, 32: internal electrode 40: conductive metal particles
50: first common particle 60: second common particle

Claims (16)

Conductive metals; And
A common material including a first common material having an average particle diameter of 10 nm and a second common material having an average particle diameter of 20 nm;
And a weight ratio of the first and second common materials is 90:10 to 70:30.
The method of claim 1,
The conductive paste composition for internal electrodes whose average particle diameter of the said conductive metal is 50-150 nm.
The method of claim 1,
The conductive metal is a conductive paste composition for internal electrodes containing nickel.
The method of claim 1,
The content of the common material is 5 to 15 parts by weight based on 100 parts by weight of the conductive metal conductive paste composition for internal electrodes.
delete The method of claim 1,
The said common material is an electrically conductive paste composition for internal electrodes containing a ceramic material.
The method according to claim 6,
And the ceramic material comprises barium titanate.
The method of claim 1,
The conductive paste composition for internal electrodes, wherein the first and second common materials are the same material.
Preparing a ceramic green sheet;
Providing a conductive paste composition comprising a conductive metal and a common material including a first common material having an average particle diameter of 10 nm and a second common material having an average particle diameter of 20 nm; And
Forming an internal electrode on the ceramic green sheet using the conductive paste composition;
And a weight ratio of the first and second common materials is 90:10 to 70:30.
10. The method of claim 9,
The average particle diameter of the said conductive metal is a manufacturing method of the multilayer ceramic electronic component of 50-150 nm.
10. The method of claim 9,
And the conductive metal comprises nickel.
10. The method of claim 9,
The content of the common material is 5 to 15 parts by weight based on 100 parts by weight of the conductive metal.
delete 10. The method of claim 9,
The common material comprises a ceramic material.
15. The method of claim 14,
And the ceramic material comprises barium titanate.
10. The method of claim 9,
And the first and second common materials are the same material.

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