KR102494335B1 - Ceramic electronic component - Google Patents

Abstract

A ceramic electronic component according to an embodiment of the present invention includes a dielectric layer and first and second internal electrodes disposed to face each other with the dielectric layer interposed therebetween, first and second surfaces facing each other, the first and third and fourth surfaces connected to the second surface and facing each other, and fifth and sixth surfaces connected to the first to fourth surfaces and facing each other; a first external electrode including a first electrode layer connected to the first internal electrode and a first conductive resin layer disposed on the first electrode layer, and disposed on a third surface of the body; and a second electrode layer connected to the second internal electrode and a second conductive resin layer disposed on the second electrode layer, the second external electrode disposed on the fourth surface of the body; When defining the distance between the third and fourth surfaces of the body as L, the thicknesses of the first and second electrode layers as ta, and the thicknesses of the first and second conductive resin layers as tb, tb is less than 80 μm, and (ta+tb)/L*50 is greater than or equal to 1.

Description

Ceramic electronic component {CERAMIC ELECTRONIC COMPONENT}

The present invention relates to ceramic electronic components.

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 that is mounted on printed circuit boards of various electronic products such as mobile phones and serves 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 capacitance, and ease of mounting. As various electronic devices such as computers and mobile devices are miniaturized and high-output, demands for miniaturization and high capacity multilayer ceramic capacitors are increasing.

Recently, as the industry's interest in electric components increases, multilayer ceramic capacitors are also required to have high reliability and high strength characteristics in order to be used in automobiles or infotainment systems.

In particular, since high flexural strength characteristics are required for multilayer ceramic capacitors, improvements in internal and external structures are required to meet this requirement.

On the other hand, as a method for securing high reliability of multilayer ceramic capacitors, in order to prevent cracks caused by stress by absorbing tensile stress generated in a mechanical or thermal environment, conductive water is applied to the external electrodes. Techniques for applying the strata are disclosed.

This conductive resin layer plays a role of electrically and mechanically bonding between the sintered electrode layer and the plating layer of the external electrode of the multilayer ceramic capacitor, and protects the multilayer ceramic capacitor from mechanical and thermal stress according to the process temperature and bending shock of the substrate during circuit board mounting. plays a more protective role.

However, the conductive resin layer has a high resistance, so there is a problem in that ESR (Equivalent Series Resistance) is high compared to products without a conductive resin layer.

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 first and second internal electrodes disposed to face each other with the dielectric layer interposed therebetween, first and second surfaces facing each other, and connected to the first and second surfaces. a body including third and fourth surfaces facing each other, and fifth and sixth surfaces connected to the first to fourth surfaces and facing each other; a first external electrode including a first electrode layer connected to the first internal electrode and a first conductive resin layer disposed on the first electrode layer, and disposed on a third surface of the body; and a second electrode layer connected to the second internal electrode and a second conductive resin layer disposed on the second electrode layer, the second external electrode disposed on the fourth surface of the body; When defining the distance between the third and fourth surfaces of the body as L, the thicknesses of the first and second electrode layers as ta, and the thicknesses of the first and second conductive resin layers as tb, tb is less than 80 μm, and (ta+tb)/L*50 is greater than or equal to 1.

As one of the various effects of the present invention, by adjusting the thickness of the electrode layer of the external electrode and the conductive resin layer in consideration of the length of the body, it is possible to reduce the equivalent series resistance (ESR) while improving the bending strength, thereby reducing the ceramic There is an effect of improving the reliability of electronic components.

However, the various advantageous advantages and effects of the present invention are not limited to the above description, and will be more easily understood in the process 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.
2 schematically illustrates a perspective view of a body according to an embodiment of the present invention.
FIG. 3 schematically illustrates a cross-section II′ of FIG. 1 .
FIG. 4(a) shows a ceramic green sheet on which a first internal electrode is printed, and FIG. 4(b) shows a ceramic green sheet on which a second internal electrode is printed.
FIG. 5 is an enlarged view of a region P1 of FIG. 3 .
FIG. 6 is an enlarged view of a region P2 of FIG. 3 .

Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and accompanying drawings. However, the embodiments of the present invention can be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the thickness is enlarged in order to clearly express various layers and regions, and components having the same function within the scope of the same idea are shown with the same reference. Explain using symbols. Furthermore, throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

In the drawing, the X direction may be defined as the second direction or length direction, the Y direction as the third direction or width direction, and the Z direction as the first direction, stacking direction, or thickness direction.

ceramic electronic components

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

2 schematically illustrates a perspective view of a body according to an embodiment of the present invention.

FIG. 3 schematically illustrates the II' cross-sectional view of FIG. 1 .

FIG. 4(a) shows a ceramic green sheet on which a first internal electrode is printed, and FIG. 4(b) shows a ceramic green sheet on which a second internal electrode is printed.

1 to 4 , a ceramic electronic component 100 according to an embodiment of the present invention includes a dielectric layer 111 and first and second internal electrodes 121 disposed to face each other with the dielectric layer interposed therebetween; 122), first and second surfaces 1 and 2 facing each other, third and fourth surfaces 3 and 4 connected to the first and second surfaces and facing each other, and the first to second surfaces 3 and 4 facing each other. A body 110 connected to the fourth surface and including fifth and sixth surfaces 5 and 6 facing each other; A first external electrode layer 131a connected to the first internal electrode 121 and a first conductive resin layer 131b disposed on the first electrode layer and disposed on the third surface of the body electrode 131; and a second electrode layer 132a connected to the second internal electrode 122 and a second conductive resin layer 132b disposed on the second electrode layer, and disposed on the fourth surface of the body. external electrode 132; When defining the distance between the third and fourth surfaces of the body as L, the thicknesses of the first and second electrode layers as ta, and the thicknesses of the first and second conductive resin layers as tb, tb is less than 80 μm, and (ta+tb)/L*50 is greater than or equal to 1.

Hereinafter, a ceramic electronic component according to an exemplary embodiment of the present disclosure will be described as a multilayer ceramic capacitor, but is not limited thereto.

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

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

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

Referring to FIG. 2, the distance between the first surface 1 and the second surface 2 is the thickness of the body (T), and the distance between the third surface 3 and the fourth surface 4 is the length of the body (L). ), the distance between the fifth surface 5 and the sixth surface 6 may be defined as the width W of the body.

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

According to one embodiment of the present invention, a raw material 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 may be used.

The material forming the dielectric layer 111 may include various ceramic additives, organic solvents, plasticizers, binders, dispersants, and the like 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 to 3 , 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 the third surface 3 ) and may be exposed through the fourth surface (4). A first external electrode 131 is disposed on the third surface 3 of the body and connected to the first internal electrode 121, and a second external electrode 132 is disposed on the fourth surface 4 of the body to make the second external electrode 131 connected to the first internal electrode 121. 2 may be connected to the internal electrode 122 .

In this case, the first and second internal electrodes 121 and 122 may be electrically separated from each other by the dielectric layer 111 disposed in the middle. Referring to FIG. 4 , the body 110 includes a ceramic green sheet (a) on which the first internal electrodes 121 are printed and a ceramic green sheet (b) on which the second internal electrodes 122 are printed, in the thickness direction (Z direction). ), and then fired to form.

Materials forming the first and second internal electrodes 121 and 122 are not particularly limited, and examples include noble metal materials such as palladium (Pd) and palladium-silver (Pd-Ag) alloys, nickel (Ni), and copper. (Cu) may be formed using a conductive paste made of one or more materials.

A screen printing method or a gravure printing method may be used as a printing method of the conductive paste, but the present invention is not limited thereto.

In this case, the ceramic electronic component 100 according to an exemplary embodiment of the present invention includes first internal electrodes 121 disposed inside the body 110 and facing each other with the dielectric layer 111 interposed therebetween. and a capacitance forming portion including the second internal electrode 122 to form a capacitance, and a cover portion 112 formed above and below the capacitance forming portion.

The cover portion 112 may 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 vertically stacking a single dielectric layer or two or more dielectric layers on the upper and lower surfaces of the capacitance forming part, respectively, and may basically serve to prevent damage to internal electrodes due to physical or chemical stress. there is.

In the ceramic electronic component 100 according to an embodiment of the present invention, the first external electrode 131 disposed on the third surface 3 of the body and the second external electrode disposed on the fourth surface 4 of the body (132).

The first external electrode 131 includes a first electrode layer 131a connected to the first internal electrode 121 and a first conductive resin layer 131b disposed on the first electrode layer 131a.

The second external electrode 132 includes a second electrode layer 132a connected to the second internal electrode 122 and a second conductive resin layer 132b disposed on the second electrode layer 132a.

The first external electrode 131 may further include a first Ni plating layer 131c disposed on the first conductive resin layer 131b and a first Sn plating layer 131d disposed on the first Ni plating layer. there is.

The second external electrode 132 may further include a second Ni plating layer 132c disposed on the second conductive resin layer 132b and a second Sn plating layer 132d disposed on the second Ni plating layer. there is.

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. It may be connected to a potential different from that of the first external electrode 131 .

The electrode layers 131a and 132a may include 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 capacitance, and for example, copper (Cu), silver (Ag), nickel ( Ni) and one or more 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 glass frit to the conductive metal powder and then firing it.

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

That is, the distance from the third surface 3 of the body 110 to the end of the band portion B of the first electrode layer 131a is greater than the distance from the end of the band portion B of the first conductive resin layer 131b. It may be short, and the distance from the fourth surface 4 of the body 110 to the end of the band portion B of the second electrode layer 132a is the distance from the end of the band portion B of the second conductive resin layer 132b. may be shorter than the distance.

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 bondability and shock absorption and can be mixed with conductive metal powder to form a paste, and may include, for example, an epoxy 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, and for example, copper (Cu), silver (Ag), nickel ( Ni) and one or more 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.

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.

The external electrodes 131 and 132 are connected to the connection part C disposed on the third or fourth surface 3 or 4 of the body and the first and second surfaces 1 and 2 in the connection part C. It may include a band portion (B) extending to a part.

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

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

FIG. 5 is an enlarged view of a region P1 of FIG. 3 .

Referring to FIGS. 2 and 5 , in the ceramic electronic component according to an exemplary embodiment of the present invention, L is the distance between the third surface 3 and the fourth surface 4 and the thickness of the first electrode layer 131a is When ta and the thickness of the first conductive resin layer 131b are defined as tb, tb is less than 80 μm, and (ta+tb)/L*50 is greater than or equal to 1.

When tb is 80 μm or more, since the thickness of the first conductive resin layer 131b is too thick, ESR (Equivalent Series Resistance) may increase. Therefore, tb is preferably less than 80 μm, more preferably 70 It may be less than μm.

When (ta + tb)/L*50 is less than 1, the thickness of the first electrode layer 131a and the first conductive resin layer 131b is insufficient to relieve stress, so there is a concern that bending strength may decrease.

As tb is less than 80 μm and (ta + tb) / L * 50 satisfies 1 or more, it is possible to reduce equivalent series resistance (ESR) while improving bending strength.

In this case, when the distance between the fifth and sixth surfaces of the body is defined as W, (ta+tb)/W*100 satisfies 2 or more, so that the bending strength can be further improved.

In addition, the thickness of the Ni plating layers 131c and 132c may be greater than or equal to 0.5 μm and less than 7 μm.

When the thickness of the Ni plating layers 131c and 132c is less than 0.5 μm, it may be difficult to secure solderability, and when the thickness exceeds 7 μm, the frequency of occurrence of bending cracks due to plating stress increases, so the flexural strength characteristics may be deteriorated.

In addition, the thickness of the Sn plating layers 131d and 132d may be between 0.5 μm and less than 12 μm.

When the thickness of the Sn plating layers 131d and 132d is less than 0.5 μm, it may be difficult to secure solderability, and when the thickness exceeds 12 μm, the frequency of occurrence of bending cracks due to plating stress increases, so the flexural strength characteristics may deteriorate.

FIG. 6 is an enlarged view of a region P2 of FIG. 3 .

Referring to FIG. 6 , in the ceramic electronic component according to an exemplary embodiment, 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.

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, a reliability problem caused by a decrease in dielectric breakdown voltage under a high voltage environment is a major issue in high voltage electronic components.

In the multilayer ceramic capacitor according to an embodiment of the present invention, the thickness td of the dielectric layer 111 is twice the thickness te of the internal electrodes 121 and 122 in order to prevent a decrease in breakdown voltage under a high voltage environment. By increasing the thickness of the dielectric layer, which is the distance between the internal electrodes, it is possible to improve the breakdown voltage characteristics.

When the thickness td of the dielectric layer 111 is less than twice the thickness te of the internal electrodes 121 and 122, the dielectric layer thickness, which is the distance between the internal electrodes, is thin and the breakdown voltage may decrease.

A thickness te of the internal electrode may be less than 1 μm, and a thickness td of the dielectric layer may be less than 2.8 μm, but are not necessarily limited thereto.

Hereinafter, in Table 1, the flexural strength and ESR (Equivalent series resistance) according to the thickness of the electrode layer (ta), the thickness of the conductive resin layer (tb), the length (L) and width (W) of the body are evaluated and shown. was

Bending strength was measured by mounting samples of multilayer ceramic capacitors on a board, setting the distance from the center to be pressed at 6 mm to observe whether cracks occurred, and if no cracks occurred, it was marked as '○', and cracks If this occurred, it was marked with 'X'.

If the ESR is less than 28.5mΩ, it is marked with '○', and if it is greater than 28.5mΩ, it is marked with 'X'.

Sample
number ta
(μm) tb
(μm) L
(mm) W
(mm) (ta+tb)/L*50 (ta+tb)/W*100 flexural strength ESR One* 10 5 1.5 0.78 0.5 1.92 X O 2 10 25 1.5 0.78 1.17 4.49 O O 3 10 40 1.5 0.78 1.67 6.41 O O 4 10 55 1.5 0.78 2.17 8.33 O O 5 30 10 1.5 0.78 1.33 5.13 O O 6 30 25 1.5 0.78 1.83 7.05 O O 7 30 40 1.5 0.78 2.33 8.97 O O 8 30 55 1.5 0.78 2.83 10.9 O O 9 45 10 1.5 0.78 1.83 7.05 O O 10 45 25 1.5 0.78 2.33 8.97 O O 11 45 40 1.5 0.78 2.83 10.9 O O 12 45 55 1.5 0.78 3.33 12.82 O O 13* 20 20 3.3 2.5 0.61 1.6 X O 14 20 50 3.3 2.5 1.06 2.8 O O 15* 20 80 3.3 2.5 1.52 4 O X 16* 20 110 3.3 2.5 1.97 5.2 O X 17 50 20 3.3 2.5 1.06 2.8 O O 18 50 50 3.3 2.5 1.52 4 O O 19* 50 80 3.3 2.5 1.97 5.2 O X 20* 50 110 3.3 2.5 2.42 6.4 O X 21 80 20 3.3 2.5 1.52 4 O O 22 80 50 3.3 2.5 1.97 5.2 O O 23* 80 80 3.3 2.5 2.42 6.4 O X 24* 80 110 3.3 2.5 2.88 7.6 O X

*: Comparative example

Referring to Table 1, according to one embodiment of the present invention, when tb is less than 80 μm and (ta + tb) / L * 50 satisfies 1 or more, it can be confirmed that the flexural strength characteristics are excellent and the ESR is low .

On the other hand, Sample Nos. 1 and 13 had (ta + tb)/L*50 of less than 1, and the flexural strength properties were poor, and Sample Nos. 15, 16, 19, 20, 23, and 24 had tb of 80 μm or more, and the ESR was poor. appeared high.

Although the 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, and is intended to be limited by the appended claims. Therefore, various forms of substitution, modification and change will be possible by those skilled in the art within the scope of the technical spirit of the present invention described in the claims, and this also 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 (14)

It includes a dielectric layer and first and second internal electrodes disposed to face each other with the dielectric layer interposed therebetween, first and second surfaces facing each other, and third and second internal electrodes connected to the first and second surfaces and facing each other. a body including a fourth surface and fifth and sixth surfaces connected to the first to fourth surfaces and facing each other;
a first external electrode including a first electrode layer connected to the first internal electrode and a first conductive resin layer disposed on the first electrode layer, and disposed on a third surface of the body; and
a second external electrode including a second electrode layer connected to the second internal electrode and a second conductive resin layer disposed on the second electrode layer, and disposed on a fourth surface of the body; including,
L is the distance between the third and fourth surfaces of the body, W is the distance between the fifth and sixth surfaces of the body, and ta is the thickness of the first and second electrode layers measured at the center of the body in the thickness direction of the body. , when the thickness of the first and second conductive resin layers is defined as tb,
tb is 20 μm or more and 55 μm or less, (ta + tb) / L * 50 is 1.06 or more and 3.33 or less, and (ta + tb) / W * 100 is 2.8 or more and 12.82 or less
ceramic electronic components.
delete According to claim 1,
The first external electrode further includes a first Ni plating layer disposed on the first conductive resin layer and a first Sn plating layer disposed on the first Ni plating layer,
The second external electrode further comprises a second Ni plating layer disposed on the second conductive resin layer and a second Sn plating layer disposed on the second Ni plating layer.
ceramic electronic components.
According to claim 3,
The thickness of the first and second Ni plating layers is 0.5 μm or more and less than 7 μm
ceramic electronic components.
According to claim 3,
The thickness of the first and second Sn plating layers is 0.5 μm or more and less than 12 μm
ceramic electronic components.
According to claim 1,
The thickness of the first and second internal electrodes is less than 1 μm, and the thickness of the dielectric layer is less than 2.8 μm.
ceramic electronic components.
According to claim 1,
When the thickness of the first and second internal electrodes is defined as te, and the thickness of the dielectric layer is defined as td,
such that td > 2*te
ceramic electronic components.
According to claim 1,
The first and second electrode layers include glass and one or more conductive metals selected from the group consisting of copper (Cu), silver (Ag), nickel (Ni), and alloys thereof.
ceramic electronic components.
According to claim 1,
The first and second conductive resin layers include 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.
According to claim 1,
The tb is 40 μm or more and 55 μm or less
ceramic electronic components.
delete delete delete According to claim 1,
The L is 1.5 mm or more and 3.3 mm or less
ceramic electronic components.

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