KR102449365B1 - Ceramic electronic component - Google Patents

Abstract

A ceramic electronic component according to an embodiment of the present invention includes a dielectric layer and a plurality of internal electrodes disposed to face each other with the dielectric layer interposed therebetween, and first and second surfaces facing each other, the first and second surfaces a body including third and fourth surfaces connected to the surface and opposite to each other, and fifth and sixth surfaces connected to the first to fourth surfaces and opposed to each other; and an external electrode including a connection portion disposed on the third or fourth surface of the body and a band portion extending from the connection portion to a portion of the first and second surfaces, wherein the external electrode includes the inner electrode and an electrode layer to be connected, a conductive resin layer disposed on the electrode layer, a Ni plating layer disposed on the conductive resin layer, and a Sn plating layer disposed on the Ni plating layer, wherein the thickness of the Ni plating layer in the connection portion is tc1, in the band portion When the Ni plating layer thickness is defined as tc2, tc1 is 0.5 μm or more, and tc2/tc1 is 1.2 or less.

Description

Ceramic electronic component {CERAMIC ELECTRONIC COMPONENT}

The present invention relates to a ceramic electronic component.

Multi-Layered Ceramic Capacitors (MLCCs), one of ceramic electronic components, are used in imaging devices such as liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, and smartphones. and a chip-type capacitor mounted on a printed circuit board of various electronic products, such as mobile phones, to charge or discharge electricity.

Such a multilayer ceramic capacitor may be used as a component of various electronic devices due to its small size, high capacity, and easy mounting. As various electronic devices such as computers and mobile devices are miniaturized and have high output, the demand for miniaturization and high capacity multilayer ceramic capacitors is increasing.

Meanwhile, as the industry's interest in electronic components has recently increased, multilayer ceramic capacitors are also required to have high reliability and high strength characteristics to be used in automobiles or infotainment systems.

In particular, since high bending strength characteristics are required for multilayer ceramic capacitors, improvements are needed in internal and external structures for improving bending characteristics.

One object of the present invention is to provide a ceramic electronic component having excellent reliability.

One embodiment of the present invention includes a dielectric layer and a plurality of internal electrodes disposed to face each other with the dielectric layer interposed therebetween, and first and second surfaces facing each other, connected to the first and second surfaces, and facing each other a body including third and fourth surfaces, fifth and sixth surfaces connected to the first to fourth surfaces and facing each other; and an external electrode including a connection portion disposed on the third or fourth surface of the body and a band portion extending from the connection portion to a portion of the first and second surfaces, wherein the external electrode includes the inner electrode and an electrode layer to be connected, a conductive resin layer disposed on the electrode layer, a Ni plating layer disposed on the conductive resin layer, and a Sn plating layer disposed on the Ni plating layer, wherein the thickness of the Ni plating layer in the connection portion is tc1, in the band portion When the Ni plating layer thickness is defined as tc2, tc1 is 0.5 μm or more and tc2/tc1 is 1.2 or less, providing a ceramic electronic component.

As one effect among the various effects of the present invention, solderability can be secured by controlling the thickness of the Ni plating layer at the connection part of the external electrode, and the thickness of the Ni plating layer at the connection part of the external electrode and the thickness of the Ni plating layer at the band part of the external electrode By adjusting the ratio, it is possible to improve the flexural strength, thereby improving reliability.

However, the various and beneficial advantages and effects of the present invention are not limited to the above, and will be more easily understood in the course of describing specific embodiments of the present invention.

1 schematically illustrates a perspective view of a ceramic electronic component according to an embodiment of the present invention.
FIG. 2 schematically illustrates a cross-sectional view II′ of FIG. 1 .
FIG. 3A shows a ceramic green sheet on which a first internal electrode is printed, and FIG. 3B shows a ceramic green sheet on which a second internal electrode is printed.
FIG. 4 is an enlarged view of region P1 of FIG. 2 .
FIG. 5 is an enlarged view of region P2 of FIG. 2 .
FIG. 6 is an enlarged view of region P3 of FIG. 2 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiment 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. Further, the embodiments of the present invention are provided in order to more completely explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for a clearer description, and elements indicated by the same reference numerals in the drawings are the same elements.

And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the thickness is enlarged to clearly express various layers and regions, and components having the same function within the scope of the same idea are referred to as the same. It is explained using symbols. Furthermore, throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

In the drawings, an X direction may be defined as a second direction, an L direction or a length direction, a Y direction may be defined as a third direction, a W direction or a width direction, and a Z direction may be defined as a first direction, a stacking direction, a T direction, or a thickness direction.

ceramic electronic components

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

FIG. 2 schematically illustrates a cross-sectional view taken along line II′ of FIG. 1 .

FIG. 3A shows a ceramic green sheet on which a first internal electrode is printed, and FIG. 3B shows a ceramic green sheet on which a second internal electrode is printed.

FIG. 4 is an enlarged view of region P1 of FIG. 2 .

FIG. 5 is an enlarged view of region P2 of FIG. 2 .

FIG. 6 is an enlarged view of region P3 of FIG. 2 .

1 to 6 , a ceramic electronic component 100 according to an embodiment of the present invention includes a dielectric layer 111 and a plurality of internal electrodes 121 and 122 disposed to face each other with the dielectric layer interposed therebetween. Including, opposite to each other, first and second surfaces (1,2), the first and second surfaces and connected to each other and opposite to each other (3, 4), the third and fourth surfaces (3, 4), the first to fourth surfaces a body 110 connected to and including fifth and sixth surfaces 5 and 6 facing each other; and external electrodes (131, 132) including a connection part (C) disposed on the third or fourth surface of the body and a band part (B) extending from the connection part to a portion of the first and second surfaces; The external electrode includes electrode layers 131a and 132a connected to the internal electrode, conductive resin layers 131b and 132b disposed on the electrode layer, and Ni plating layers 131c and 132c disposed on the conductive resin layer. and Sn plating layers 131d and 132d disposed on the Ni plating layer, wherein the thickness of the Ni plating layer in the connection portion is defined as tc1 and the thickness of the Ni plating layer in the band portion is defined as tc2, tc1 is 0.5 μm or more, and tc2/ tc1 satisfies 1.2 or less.

Hereinafter, a ceramic electronic component according to an embodiment of the present invention will be described, and in particular, a multilayer ceramic capacitor will be described, but the present invention is not limited thereto.

In the body 110 , a dielectric layer 111 and internal electrodes 121 and 122 are alternately stacked.

The specific shape of the body 110 is not particularly limited, but as shown, the body 110 may have a hexahedral shape or a similar shape. Due to the shrinkage of the ceramic powder included in the body 110 during the firing process, the body 110 may not have a perfectly straight hexahedral shape, but may have a substantially hexahedral shape.

The body 110 is connected to the first and second surfaces 1 and 2 facing each other in the thickness direction (Z direction), the first and second surfaces 1 and 2, and is connected to each other in the longitudinal direction (X direction). The third and fourth surfaces 3 and 4 opposite to each other, the first and second surfaces 1 and 2 are connected, and the third and fourth surfaces 3 and 4 are connected to each other in the width direction (Y direction). It may have opposing fifth and sixth surfaces 5 , 6 .

The plurality of dielectric layers 111 forming the body 110 are in a fired state, and the boundary between the adjacent dielectric layers 111 can be integrated to the extent that it is difficult to check without using a scanning electron microscope (SEM). have.

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. For example, a barium titanate-based material, a lead composite perovskite-based material, or a strontium titanate-based material can be used.

As a material for forming the dielectric layer 111 , various ceramic additives, organic solvents, plasticizers, binders, dispersants, etc. may be added to powder such as barium titanate (BaTiO ₃ ) according to the purpose of the present invention.

The plurality of internal electrodes 121 and 122 are disposed to face each other with the dielectric layer 111 interposed therebetween.

The internal electrodes 121 and 122 may include first and second internal electrodes 121 and 122 alternately disposed to face each other with a dielectric layer interposed therebetween.

The first and second internal electrodes 121 and 122 may be exposed to the third and fourth surfaces 3 and 4 of the body 110 , respectively.

1 and 2 , the first internal electrode 121 is spaced apart from the fourth surface 4 and exposed through the third surface 3 , and the second internal electrode 122 is formed on the third surface 3 . ) and spaced apart and may be exposed through the fourth surface (4). A first external electrode 131 is disposed on the third surface 3 of the body to be connected to the first internal electrode 121 , and a second external electrode 132 is disposed on the fourth surface 4 of the body to form the first external electrode 131 . 2 may be connected to the internal electrode 122 .

In this case, the first and second internal electrodes 121 and 122 may be electrically isolated from each other by the dielectric layer 111 disposed in the middle. Referring to FIG. 3 , the body 110 forms a ceramic green sheet a on which the first internal electrode 121 is printed and a ceramic green sheet b on which the second internal electrode 122 is printed in the thickness direction (Z direction). ) can be alternately laminated and then fired to form.

Materials forming the first and second internal electrodes 121 and 122 are not particularly limited, and for example, noble metal materials such as palladium (Pd), palladium-silver (Pd-Ag) alloy, and nickel (Ni) and copper It may be formed using a conductive paste made of at least one of (Cu).

The method for printing the conductive paste may use a screen printing method or a gravure printing method, but the present invention is not limited thereto.

In this case, the ceramic electronic component 100 according to the exemplary embodiment of the present invention is disposed inside the body 110 , and the first internal electrodes 121 are disposed to face each other with the dielectric layer 111 interposed therebetween. and a capacitor forming part in which a capacitor is formed including the second internal electrode 122 , and a cover part 112 formed above and below the capacitor forming part.

The cover part 112 does not include the internal electrodes 121 and 122 and may include the same material as the dielectric layer 111 . That is, the cover part 112 may include a ceramic material, for example, a barium titanate-based material, a lead composite perovskite-based material, or a strontium titanate-based material.

The cover part 112 may be formed by stacking a single dielectric layer or two or more dielectric layers on the upper and lower surfaces of the capacitor forming part in the vertical direction, and basically serves to prevent damage to the internal electrode due to physical or chemical stress. have.

The ceramic electronic component 100 according to an embodiment of the present invention includes a connection portion C disposed on a third surface 3 or a fourth surface 4 of a body, and the first and second portions at the connection portion C. and external electrodes 131 and 132 including a band portion B extending to a portion of the two surfaces 1 and 2 .

At this time, the band portion (B) may extend not only a portion of the first and second surfaces (1, 2), but also a portion of the fifth and sixth surfaces (5, 6) from the connection portion (C).

The external electrodes 131 and 132 may include a first external electrode 131 in which a connection part is disposed on a third surface and a second external electrode 132 in which a connection part is disposed on a fourth surface.

The first and second external electrodes 131 and 132 may be electrically connected to the first and second internal electrodes 121 and 122, respectively, to form capacitance, and the second external electrode 132 may be It may be connected to a potential different from that of the first external electrode 131 .

Hereinafter, the first external electrode 131 will be mainly described, but the same may be applied to the second external electrode 132 .

The external electrodes 131 and 132 include electrode layers 131a and 132a connected to the internal electrodes 121 and 122, conductive resin layers 131b and 132b disposed on the electrode layer, and Ni disposed on the conductive resin layer. and plating layers 131c and 132c and Sn plating layers 131d and 132d disposed on the Ni plating layer.

The electrode layers 131a and 132a may include a conductive metal and glass.

The conductive metal used for the electrode layers 131a and 132a is not particularly limited as long as it is a material that can be electrically connected to the internal electrode to form a capacitance, and for example, copper (Cu), silver (Ag), nickel ( Ni) and may be at least one selected from the group consisting of alloys thereof.

The electrode layers 131a and 132a may be formed by applying a conductive paste prepared by adding a glass frit to the conductive metal powder and then firing.

The conductive resin layers 131b and 132b are formed on the electrode layers 131a and 132a and may be formed to completely cover the electrode layers 131a and 132a.

The conductive resin layers 131b and 132b may include a conductive metal and a base resin.

The base resin included in the conductive resin layers 131b and 132b is not particularly limited as long as it has bonding properties and shock absorption properties, and can be mixed with conductive metal powder to make a paste, and may include, for example, an epoxy-based resin. .

The conductive metal included in the conductive resin layers 131b and 132b is not particularly limited as long as it is a material that can be electrically connected to the electrode layers 131a and 132a. For example, copper (Cu), silver (Ag), nickel ( Ni) and may include at least one selected from the group consisting of alloys thereof.

The Ni plating layers 131c and 132c are formed on the conductive resin layers 131b and 132b and may be formed to completely cover the conductive resin layers 131b and 132b.

FIG. 4 is an enlarged view of region P1 of FIG. 2 .

FIG. 5 is an enlarged view of region P2 of FIG. 2 .

4 and 5 , in the ceramic electronic component according to an embodiment of the present invention, when the thickness of the Ni plating layer in the connection part (C) is defined as tc1 and the thickness of the Ni plating layer in the band part (B) is defined as tc2 , tc1 may be 0.5 μm or more, and tc2/tc1 may be 1.2 or less.

When the thickness tc1 of the Ni plating layer in the connection portion C is less than 0.5 μm, it may be difficult to secure solderability.

When tc2/tc1 is more than 1.2, the stress difference between the connection part (C) and the band part (B) is too large, so the bending strength is lowered and the frequency of occurrence of bending cracks may increase.

By adjusting tc2/tc1 to 1.2 or less, it is possible to secure a flexural strength of 5 mm or more.

In this case, tc2/tc1 may be greater than 1.0 and less than or equal to 1.2.

By adjusting the thickness of the Ni plating layer (tc2) in the band portion (B) to be thicker than the thickness of the Ni plating layer (tc1) in the connection portion (C), that is, by adjusting tc2/tc1 to more than 1.0, solderability can be further improved.

The thickness of the Ni plating layer (tc1) in the connection portion may be measured at the center of the connection portion (C), and the thickness of the Ni plating layer in the band portion (tc2) may be measured at the center of the band portion (B).

The Sn plating layers 131d and 132d are formed on the Ni plating layers 131c and 132c, and may be formed to completely cover the Ni plating layers 131c and 132c.

The Sn plating layers 131d and 132d serve to improve mounting characteristics.

FIG. 6 is an enlarged view of region P3 of FIG. 2 .

Referring to FIG. 6 , in the ceramic electronic component according to the embodiment of the present invention, the thickness td of the dielectric layer 111 and the thickness te of the internal electrodes 121 and 122 are td > 2*te can be satisfied with

That is, according to an embodiment of the present invention, the thickness td of the dielectric layer 111 is greater than twice the thickness te of the internal electrodes 121 and 122 .

In general, in high voltage electronic components, a reliability problem due to a decrease in breakdown voltage under a high voltage environment is a major issue.

In the multilayer ceramic capacitor according to the exemplary embodiment of the present invention, the thickness td of the dielectric layer 111 is doubled as the thickness te of the internal electrodes 121 and 122 in order to prevent the breakdown voltage from being lowered under a high voltage environment. By making it larger, the dielectric breakdown voltage characteristic can be improved by increasing the thickness of the dielectric layer, which is the distance between the internal electrodes.

When the thickness td of the dielectric layer 111 is equal to or less than twice the thickness te of the internal electrodes 121 and 122 , the dielectric layer, which is the distance between the internal electrodes, is thin, so that the breakdown voltage may be reduced.

The thickness te of the internal electrode may be less than 1 μm, and the thickness td of the dielectric layer may be less than 2.8 μm, but is not limited thereto.

Hereinafter, Table 1 shows the evaluation of solderability and whip strength according to the Ni plating layer thickness (tc1) of the connection part and the Ni plating layer thickness (tc2) of the band part.

tc1 and tc2 are measured at the center of the connection part and the band part, respectively.

Solderability was indicated by '○' when more than 95 area% of the external electrode was covered with solder by dipping the external electrodes of samples of the multilayer ceramic capacitor into solder, and 'X' when less than 95 area% was indicated.

Flexural strength was measured by mounting the samples of the multilayer ceramic capacitor on the substrate and then setting the distance from the center to which it is pressed during bending to 5 mm and observing whether cracks occurred. When cracks occurred, it was marked with an 'X'.

sample number tc1 tc2 tc2/tc1 solderability flexural strength One 0.5 0.4 0.80 ○ ○ 2 1.0 0.8 0.80 ○ ○ 3 1.5 1.5 1.00 ○ ○ 4 2.0 2.0 1.00 ○ ○ 5 2.5 2.4 0.96 ○ ○ 6 3.0 3.1 1.03 ○ ○ 7 3.5 3.4 0.97 ○ ○ 8 4.0 4.2 1.05 ○ ○ 9 4.5 4.9 1.09 ○ ○ 10 5.0 5.7 1.14 ○ ○ 11* 5.5 6.7 1.22 ○ X 12* 6.0 8.0 1.33 ○ X 13* 6.5 8.8 1.35 ○ X 14* 7.0 9.1 1.30 ○ X 15* 7.5 10.7 1.43 ○ X 16* 8.0 12.3 1.54 ○ X 17* 8.5 13.3 1.56 ○ X 18* 9.0 15.0 1.67 ○ X 19* 9.5 16.5 1.74 ○ X 20* 10.0 17.8 1.78 ○ X

Referring to Table 1, according to an embodiment of the present invention, in the case of Sample Nos. 1 to 10, wherein tc1 is 0.5 μm or more and tc2/tc1 is 1.2 or less, it can be confirmed that solderability and flexural strength characteristics are excellent.

On the other hand, in the case of Sample Nos. 11 to 20, tc1 was 0.5 μm or more, and solderability was excellent, but tc2/tc1 exceeded 1.2, so the stress difference between the connection part (C) and the band part (B) was too large, so bending cracks occurred Therefore, the flexural strength characteristics were inferior.

Although embodiments of the present invention have been described in detail above, the present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

100: ceramic electronic component
110: body
121, 122: internal electrode
111: dielectric layer
112: cover part
131,132: external electrode

Claims (7)

a dielectric layer and a plurality of internal electrodes disposed to face each other with the dielectric layer interposed therebetween, wherein first and second surfaces facing each other in a first direction are connected to the first and second surfaces and are connected to each other in a second direction a body including third and fourth opposing surfaces, fifth and sixth surfaces connected to the first to fourth surfaces and facing each other in a third direction; and
and an external electrode including a connection part disposed on the third or fourth surface of the body and a band part extending from the connection part to a portion of the first and second surfaces; and
The external electrode includes an electrode layer connected to the internal electrode, a conductive resin layer disposed on the electrode layer, a Ni plating layer disposed on the conductive resin layer, and a Sn plating layer disposed on the Ni plating layer,
When the thickness of the Ni plating layer in the central portion in the first direction of the connection portion is defined as tc1 and the thickness of the Ni plating layer in the center portion in the second direction of the band portion is defined as tc2, tc1 is 0.5 μm or more and 5.0 μm or less, and tc2/tc1 is 1.2 or less
Ceramic electronic components.
According to claim 1,
wherein tc2/tc1 is greater than 1.0 and less than or equal to 1.2
Ceramic electronic components.
According to claim 1,
The thickness of the inner electrode is less than 1 ㎛
Ceramic electronic components.
According to claim 1,
The thickness of the dielectric layer is less than 2.8 ㎛
Ceramic electronic components.
According to claim 1,
When the thickness of the internal electrode is defined as te and the thickness of the dielectric layer is defined as td,
td > 2*te
Ceramic electronic components.
According to claim 1,
The electrode layer includes at least one conductive metal selected from the group consisting of copper (Cu), silver (Ag), nickel (Ni), and alloys thereof and glass.
Ceramic electronic components.
According to claim 1,
The conductive resin layer includes at least one conductive metal selected from the group consisting of copper (Cu), silver (Ag), nickel (Ni), and alloys thereof and a base resin.
Ceramic electronic components.

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