KR20140032212A - Conductive resin composition and multilayer ceramic components having the same - Google Patents

Abstract

The present invention relates to a conductive resin composition and multi-layered ceramic electronic parts including the same. According to one embodiment of the present invention, provided is the conductive resin composition which includes an epoxy resin, metal powder in which the ratio of a major axis and a minor axis is 1-7, and a hardener. The metal powder is at least one selected from silver (Ag), copper (Cu), nickel (Ni), copper coated with silver, and copper-nickel alloy.

Description

CONDUCTIVE RESIN COMPOSITION and MULTILAYER CERAMIC COMPONENTS HAVING THE SAME

The present invention relates to a conductive resin composition and a multilayer ceramic electronic component including the same.

Electronic components using ceramic materials include capacitors, inductors, piezoelectric elements, varistors and thermistors.

A multi-layered ceramic capacitor (MLCC) of the ceramic electronic part is formed of a ceramic body made of a ceramic material, an internal electrode formed inside the ceramic body, and a ceramic body formed on the ceramic body so as to be electrically connected to the internal electrode And has an advantage of being small in size, high in capacity, and easy to be mounted.

Because of these advantages, the multilayer ceramic capacitor is used as a chip-type capacitor which is mounted on a printed circuit board of various electronic products such as a computer, a personal digital assistant (PDA) and a mobile phone and plays an important role in charging or discharging electricity, And may have various sizes and laminated shapes depending on the intended use and capacity.

In recent years, with the miniaturization of electronic products, the multilayer ceramic capacitors have been required to be miniaturized and have a high capacity. To this end, a multilayer ceramic capacitor having a structure in which a dielectric layer and an internal electrode are thinned and a larger number of dielectric layers and internal electrodes are laminated is manufactured.

Such a very small and ultra-high-capacity multilayer ceramic capacitor is required to have high reliability in conformity with the many functions of the field requiring high reliability such as automobiles and medical devices.

Problems such as high reliability may include cracking of the external electrode due to external impact, or a plating solution penetrating into the ceramic element through the external electrode during the plating process. There is a need for a product that does not generate warpage cracks even after

In order to solve the above problems, it is possible to absorb the external shock and effectively block the penetration of the plating solution by applying the epoxy which gives the flexible property between the external electrode and the plating layer and the conductive epoxy which added the metal component which gives the conductivity. To improve.

However, in the related art, there is a problem in that void defects occur a lot when the external component is applied to the external electrode as a metal component of the conductive epoxy is flaked.

In addition, according to the ultra-miniaturization and ultra-high capacity of the product is also required to thin the external electrode, the conventional conductive epoxy has a high viscosity ratio, the corner portion of the external electrode is thin, but the thickness of the central portion was a problem.

In the art, new methods have been required to improve the problems of voids generated when the conductive resin composition is applied to the external electrode, and a thick portion of the central portion of the external electrode due to the high viscosity ratio of the conductive resin composition.

One aspect of the invention, the epoxy resin; Metal powder having a long axis ratio and a short axis ratio of 1 to 7; And curing agents; And a conductive resin composition.

In one embodiment of the present invention, the conductive resin composition may further include an elastomer.

In one embodiment of the present invention, the average particle diameter of the metal powder may be 0.5 to 30 ㎛.

In one embodiment of the present invention, the metal powder may be at least one selected from silver (Ag), copper (Cu), nickel (Ni), copper coated with silver on the surface and a copper-nickel alloy.

According to another aspect of the present invention, there is provided a plasma processing apparatus comprising: a ceramic body having a plurality of dielectric layers stacked; A plurality of first and second internal electrodes formed on at least one surface of the dielectric layer and alternately exposed through both end faces of the ceramic body; First and second external electrode layers formed on both end surfaces of the ceramic element and electrically connected to the first and second internal electrodes; And first and second conductive resin layers formed to cover the first and second external electrode layers. Wherein the first and second conductive resin layers provide a multilayer ceramic electronic component composed of an epoxy resin, a conductive resin composition comprising a metal powder, a curing agent, and an elastomer having a long axis ratio and a short axis ratio of 1 to 7.

In one embodiment of the present invention, the first and second plating layers may be formed on the surfaces of the first and second conductive resin layers.

In one embodiment of the present invention, the first and second plating layer is composed of a nickel (Ni) plating layer formed on the surface of the first and second external electrode, and a tin (Sn) plating layer formed on the surface of the nickel plating layer. Can be.

According to one embodiment of the present invention, while maintaining high reliability and high bending crack characteristics, by controlling the degree of flake formation of the metal powder contained in the conductive resin composition to prevent the generation of voids when applied to the external electrode, conductive resin By lowering the viscosity ratio of the composition, the thickness of the center portion of the external electrode becomes thick and the edge portion has an effect of minimizing the problem.

1 is a perspective view schematically showing a multilayer ceramic capacitor according to an embodiment of the present invention.
2 is a sectional view taken along the line A-A 'in Fig.
3 is a scanning electron microscope (SEM) photograph showing a cross-sectional fine structure of an external electrode formed of a conductive resin composition according to an embodiment of the present invention.
FIG. 4 is a scanning electron microscope (SEM) photograph showing one side cross section of the multilayer ceramic capacitor according to the exemplary embodiment of the present invention.
5 is an enlarged cross-sectional view of a portion B of FIG. 4.

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

However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

Moreover, embodiment of this invention is provided in order to demonstrate this invention more completely to the person with average knowledge in the technical field.

The shape and size of elements in the drawings may be exaggerated for clarity.

The present invention relates to a ceramic electronic component, and a ceramic electronic component according to an embodiment of the present invention includes a multilayer ceramic capacitor, an inductor, a piezoelectric element, a varistor, a chip resistor and a thermistor, The multilayer ceramic capacitor will be described.

1 and 2, the multilayer ceramic capacitor 100 according to the present embodiment includes a ceramic element 110 in which a plurality of dielectric layers 111 are stacked, and a plurality of first surfaces formed on at least one surface of the dielectric layer 111. And first and second external electrode layers 131 and 132 formed at both end surfaces of the second internal electrodes 121 and 122 and the ceramic body 110 and electrically connected to the first and second internal electrodes 121 and 122. ) And first and second conductive resin layers 133 and 134 formed on the surfaces of the first and second external electrode layers 131 and 132.

The ceramic body 110 is formed by laminating a plurality of dielectric layers 111 and then firing, and each of the adjacent dielectric layers 111 can be integrated to such an extent that boundaries can not be confirmed.

In addition, the ceramic body 110 may generally have a rectangular parallelepiped shape, but the present invention is not limited thereto.

In addition, the ceramic element 110 is not particularly limited in size, for example, it may be configured in a size such as 0.6 mm × 0.3 mm to configure a high capacitance multilayer ceramic capacitor 100.

A dielectric cover layer (not shown) having a predetermined thickness may be further formed on the outermost surface of the ceramic body 110 if necessary.

The dielectric layer 111 contributes to the capacitance formation of the capacitor, and the thickness of one layer may be arbitrarily changed in accordance with the capacitance design of the multilayer ceramic capacitor 100. Preferably, the thickness of the one layer is 0.1 to 1.0 μm after firing. It may be configured, but the present invention is not limited thereto.

In addition, the dielectric layer 111 may include a ceramic material having a high dielectric constant, for example, BaTiO ₃ ceramic powder, but the present invention is not limited thereto.

The BaTiO ₃ based ceramic powder is, for example, the BaTiO ₃ Ca, Zr, etc., some employ the _{(Ba 1-x Ca x)} TiO 3, Ba (Ti 1 - y Ca y) O 3, (Ba 1 - x Ca _x ) (Ti _{1 - y} Zr _y ) O ₃ or Ba (Ti _{1 - y} Zr _y ) O ₃ , and the present invention is not limited thereto.

On the other hand, the dielectric layer 111 together with such ceramic powder, for example, various ceramic additives such as transition metal oxides or carbides, rare earth elements, magnesium (Mg) or aluminum (Al), organic solvents, plasticizers, binders and dispersants, etc. Further may be added.

The first and second internal electrodes 121 and 122 are formed on and laminated on a ceramic sheet forming a dielectric layer 111 and then fired to form a ceramic body 110 with one dielectric layer 111 sandwiched therebetween. .

The first and second internal electrodes 121 and 122 may be formed by printing a conductive paste on at least one surface of the dielectric layer 11 to a predetermined thickness. As the printing method of the conductive paste, a screen printing method or a gravure printing method may be used, but the present invention is not limited thereto.

The first and second internal electrodes 121 and 122 are a pair of electrodes having polarities different from each other. The first and second internal electrodes 121 and 122 are disposed opposite to each other in the stacking direction of the dielectric layers 111, They are electrically insulated from each other.

In addition, one end of each of the first and second internal electrodes 121 and 122 may be exposed through both end surfaces of the ceramic element 110, and the first and second alternating portions may be alternately exposed through one end surface of the ceramic element 110. One end of the second internal electrodes 121 and 122 may be electrically connected to the first and second external electrode layers 131 and 132, respectively.

The first and second internal electrodes 121 and 122 may be formed of a conductive metal such as Ni or Ni alloy, but the present invention is not limited thereto.

Accordingly, when a predetermined voltage is applied to the first and second external electrodes, charges are accumulated between the first and second internal electrodes 121 and 122 facing each other, and the capacitance of the multilayer ceramic capacitor 100 is mutually different. It is proportional to the area of the first and second internal electrodes 121 and 122 facing.

The first and second external electrode layers 131 and 132 may be formed of a conductive paste for external electrodes containing copper powder.

The external electrode conductive paste may be prepared by mixing a glass frit, a base resin, and an organic vehicle made of an organic solvent with the copper powder.

That is, when the conductive paste for the external electrode thus prepared is applied to both end surfaces of the ceramic body 110 and the ceramic body 110 is fired, the metal powder in the conductive paste for the external electrode is sintered to form the first and second external electrode layers 131. , 132 may be formed.

In this case, the first and second external electrode layers 131 and 132 may be formed by shortening a band because the purpose is to implement contactability.

Subsequently, the first and second external electrode layers 131 and 132 are fired, and a conductive resin composition is coated on the surfaces of the first and second external electrode layers 131 and 132 so that the first and second conductive resin layers 133, After forming 134, curing is performed to form first and second external electrodes.

In this case, the conductive resin composition is in a state in which an epoxy resin and a curing agent are dissolved in a solvent, and can be prepared by adding a metal powder thereto.

When the epoxy resin is applied to the first and second external electrode layers 131 and 132, the solvent is removed during the drying process, and only the metal powder, the epoxy resin, and the curing agent remain, and the epoxy resin is cured by the heat treatment process. Such components can maintain high reliability and high bending cracks when forming external electrodes.

In addition, an elastomer may be added to the epoxy resin to make the structure more flexible.

The metal flake powder of the conductive resin composition may have a ratio of long axis to short axis of 1 to 7. In addition, the average particle diameter of the metal powder may be 0.5 to 30 ㎛. Metal powder of the conductive resin composition may be used by mixing a sphere and a flake (or plate) or each. Double spherical powder refers to a metal having a ratio of major axis to minor axis of about 1, and flake powder refers to powder having different sizes of major axis and minor axis.

The flake refers to a metal form in which the major axis and the minor axis are different in size by milling or synthesizing. In this embodiment, by using the metal powder with less flakes as described above, the viscosity ratio of the conductive resin composition is lowered to prevent void defects therein. When it is suppressed from occurring and applied to cover the first and second external electrode layers 131 and 132, the problem that the center portion of the external electrode becomes thick and the corner portion becomes thin can be improved.

The metal powder may be at least one selected from silver (Ag), copper (Cu), nickel (Ni), copper coated with silver on the surface, and a copper-nickel alloy.

The first and second plating layers may be formed to further increase the adhesive strength when the multilayer ceramic capacitor 100 of the first and second conductive resin layers 133 and 134 is mounted on a substrate or the like.

At this time, the plating treatment is performed according to a known method, and it is preferable to perform lead-free plating in consideration of the environment, but the present invention is not limited thereto.

The first and second plating layers include a pair of nickel (Ni) plating layers 135 and 136 formed on outer surfaces of the first and second conductive resin layers 133 and 134, respectively, and respective nickel plating layers 135 and 136. It may be composed of a pair of tin (Sn) plating layer (137, 138) formed on the outer surface of the).

Table 1 below shows the viscosity and the viscosity ratio of the conductive resin composition according to the degree of flaking of the metal powder according to the conditions.

Sample Comparative Example Example Viscosity (Pa.s) 1 RPM 62.8 32.9 10 RPM 13.5 12.9 100 RPM 5.9 12.4 Viscosity Ratio (T.I) 1/10 RPM 4.7 2.6 10/100 RPM 2.3 1.0

Here, referring to Table 2 below, the metal powder of the conductive resin composition of the Comparative Example used a ratio of the long axis and the short axis is greater than 7, the metal powder of the conductive resin composition of the embodiment used that the ratio of the long axis and short axis is 1 to 7. It was.

Example Comparative Example 1 One 4.657214 10.21768 2 4.390909 16.80773 3 4.614908 16.4469 4 2.465495 12.96925 5 5.029646 17.46441 6 5.229221 12.0416 7 6.200013 7.60114 8 3.247887 8.223451 9 4.390909 15.95306 10 5.207466 12.74768 11 6.264952 8.31038 12 3.090403 11.59752 13 3.498567 9.402178 14 3.538438 11.08047 15 3.179259 10.67182 16 5.587711 17.00014 17 4.809974 8.100361 18 2.838223 15.23156

<Ratio of major and minor axis of metal powder samples used in Comparative Examples and Examples>

In Table 1, as a result of confirming the viscosity ratio of the comparative example and the example, the viscosity ratio of the comparative example was 4.7 at 1/10 RPM, whereas in the case of Example was greatly lowered to 2.6, especially the viscosity at a low shear rate (low shear rate) It was confirmed that the lowering to about 1/2.

In addition, as a result of confirming the cross-sectional structure of the external electrode with reference to FIG.

In addition, the coated shape comparative example is generally thick in the center of the outer electrode and the thinner corner portion, while referring to Figures 4 and 5, the embodiment can confirm that the center portion of the outer electrode is thinner.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.

100; A multilayer ceramic capacitor 110; Ceramic body
111; Dielectric layers 121 and 122; The first and second internal electrodes
131, 132; First and second external electrode layers
133, 134; The first and second conductive resin layers
135, 136; Nickel (Ni) Plating Layer
137, 138; Tin (Sn) Plating Layer

Claims (10)

Epoxy resin;
Metal powder having a long axis ratio and a short axis ratio of 1 to 7; And
Curing agent; .
The method of claim 1,
A conductive resin composition further comprising an elastomer.
The method of claim 1,
The average particle diameter of the said metal powder is 0.5-30 micrometers, The conductive resin composition characterized by the above-mentioned.
The method of claim 1,
The metal powder is at least one selected from silver (Ag), copper (Cu), nickel (Ni), copper coated with silver on the surface, and a copper-nickel alloy.
A ceramic body in which a plurality of dielectric layers are stacked;
A plurality of first and second internal electrodes formed on at least one surface of the dielectric layer and alternately exposed through both end faces of the ceramic body;
First and second external electrode layers formed on both end surfaces of the ceramic element and electrically connected to the first and second internal electrodes; And
First and second conductive resin layers formed to cover the first and second external electrode layers; / RTI &gt;
The first and second conductive resin layers are laminated ceramic electronic components composed of an epoxy resin, a conductive resin composition comprising a metal powder, a curing agent and an elastomer having a long axis ratio and a short axis ratio of 1 to 7.
6. The method of claim 5,
The conductive resin composition is a multilayer ceramic electronic component, characterized in that it further comprises an elastomer.
6. The method of claim 5,
Laminated ceramic electronic component, characterized in that the average particle diameter of the metal powder is 0.5 to 30㎛.
6. The method of claim 5,
The metal powder is at least one selected from silver (Ag), copper (Cu), nickel (Ni), copper coated with silver on the surface, and a copper-nickel alloy.
6. The method of claim 5,
The multilayer ceramic electronic component further comprising first and second plating layers formed on surfaces of the first and second conductive resin layers.
10. The method of claim 9,
The first and second plating layers may include a nickel (Ni) plating layer formed on the surfaces of the first and second external electrodes and a tin (Sn) plating layer formed on the surface of the nickel plating layer. .

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