Multilayer electronic component and dielectric composition

Abstract

To provide a laminate type electronic part which is superior in reliability, enables the materialization of a uniform grain non-growth area, is reduced in DF (Dissipation Factor) and effective capacity change rate, and has excellent voltage resistance and superior dielectric constant characteristic, and to provide a dielectric composition.SOLUTION: A laminate type electronic part comprises: a body 110 including dielectric layers 111 and internal electrodes 121, 122 disposed so as to alternate with the dielectric layers; and external electrodes 131, 132 disposed on the body. Of a plurality of dielectric crystal grains included in the dielectric layer, the number percentage of dielectric crystal grains of 100-250 nm in size is 55% or more. A dielectric composition comprises a BaTiO3-based primary component and a first secondary component, in which the first secondary component comprises BaCO3 and SiO2, and the content of BaCO3 is 4.0 mol% or more to 100 mol of Ti of the primary component, and the content of SiO2 is 7.0 mol% or more to 100 mol of Ti of the primary component.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a multilayer electronic component and a dielectric composition.

Background Art

[0002] A multilayer ceramic capacitor (MLCC), which is one of multilayer electronic components, is a chip-shaped capacitor mounted on a printed circuit board of various electronic products such as video equipment like a liquid crystal display (LCD) and a plasma display panel (PDP), a computer, a smartphone, and a mobile phone, and serves to charge or discharge electricity.

[0003] Such a multilayer ceramic capacitor can be used as a component of various electronic devices because of its merits of being small-sized, having a guaranteed high capacitance, and being easy to mount. As various electronic devices such as computers and mobile devices are miniaturized and have increased output, the needs for miniaturization and high capacitance of multilayer ceramic capacitors are increasing.

[0004] In order to achieve miniaturization and high capacitance of a multilayer ceramic capacitor, it is necessary to reduce the thickness of the dielectric layer and the internal electrodes and increase the number of layers. Currently, the thickness of the dielectric layer has reached a level of about 0.6 μm, and the thinning continues.

[0005] However, the thinner the dielectric layer becomes, the greater the electric field applied per unit thickness. Therefore, problems such as an increase in the change rate of temperature and effective capacitance and a decrease in breakdown voltage occur, and there is a risk of a decrease in reliability.

[0006] In order to solve such problems, there is a need for a new method that can ensure high reliability not only from the structural aspect of the multilayer ceramic capacitor but also particularly from the compositional aspect of the dielectric.

[0007] If a dielectric composition capable of further enhancing the reliability level from the current level can be secured, it is expected that a more thinly laminated multilayer ceramic capacitor can be manufactured.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] One of the various objects of the present invention is to provide a multilayer electronic component and a dielectric composition having excellent reliability.

[0009] One of the various objects of the present invention is to provide a multilayer electronic component and a dielectric composition capable of realizing a uniform non-grain growth boundary.

[0010] One of the various objects of the present invention is to provide a multilayer electronic component and a dielectric composition in which the DF (Dissipation Factor) and the effective capacitance change rate are reduced.

[0011] One of the various objects of the present invention is to provide a multilayer electronic component and a dielectric composition having excellent withstand voltage characteristics and dielectric constant characteristics.

[0012] However, the object of the present invention is not limited to the above content, and can be more easily understood in the process of describing the specific embodiments of the present invention.

MEANS FOR SOLVING THE PROBLEMS

[0013] The dielectric composition according to one embodiment of the present invention includes a BaTiO3-based main component and a first sub-component, the first sub-component includes BaCO3 and SiO2, the BaCO3 is 4.0 mol% or more with respect to 100 mol of Ti of the main component, and the content of the SiO2 is 7.0 mol% or more with respect to 100 mol of Ti of the main component.

[0014] A multilayer electronic component according to an embodiment of the present invention includes a main body including a dielectric layer and internal electrodes alternately arranged with the dielectric layer, and external electrodes arranged on the main body. Among the plurality of dielectric crystallites included in the dielectric layer, the number ratio of dielectric crystallites having a size of 100 to 250 nm is 55% or more.

Effects of the Invention

[0015] As one of various effects of the present invention, the reliability of the multilayer electronic component and the dielectric composition can be improved.

[0016] However, the various and beneficial advantages and effects of the present invention are not limited to the above contents, and can be more easily understood in the process of describing the specific embodiments of the present invention.

Brief Description of the Drawings

[0017]

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Figure 2

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Figure 10

Embodiments for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, 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. Also, the embodiments of the present invention are provided to more fully explain the present invention to those having average knowledge in the technical field. Therefore, the shapes and sizes of the elements in the drawings may be enlarged, reduced (or emphasized or simplified) for clearer explanation, and the elements indicated by the same reference numerals in the drawings are the same elements.

[0019] In the drawings, in order to clearly explain the present invention, parts not related to the explanation are omitted, and the sizes and thicknesses of each configuration shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to the illustrated places. Also, components having the same function within the scope of the same idea are described using the same reference numerals. Further, throughout the specification, when a certain part "includes" a certain component, this does not exclude other components and means that other components can be further included unless otherwise stated to the contrary.

[0020] In the drawings, the first direction can be defined as the stacking direction or the thickness (T) direction, the second direction as the length (L) direction, and the third direction as the width (W) direction.

[0021] [Dielectric Composition] The dielectric composition according to an embodiment of the present invention contains a BaTiO3-based main component and a first sub-component. The first sub-component contains BaCO3 and SiO2. The BaCO3 is 4.0 mol% or more with respect to 100 mol of Ti in the main component, and the content of the SiO2 is 7.0 mol% or more with respect to 100 mol of Ti in the main component.

[0022] Generally, an increase in DF (Dissipation Factor), an increase in the effective capacitance change rate, a decrease in the breakdown voltage, etc. are known to be caused by the dispersion of dielectric crystal grain sizes accompanied by abnormal grain growth.

[0023] Also, when liquid elements such as BaCO3 and SiO2 are added, it is known to induce abnormal grain growth. Therefore, conventionally, it has been common to add a small amount of liquid elements such as BaCO3 and SiO2.

[0024] In contrast, in the present invention, by adding a large amount of liquid elements to simultaneously induce abnormal grain growth in multiple locations, grain impingement ensures a uniform fine structure due to uniform grain growth rather than the growth of selectively some particles. As a result, effects such as a decrease in DF (Dissipation Factor) and the effective capacitance change rate, and an improvement in the breakdown voltage can be ensured, and the reliability of multilayer electronic components can be improved.

[0025] According to an embodiment of the present invention, by adding BaCO3 at 4.0 mol% or more with respect to 100 mol of Ti in the BaTiO3-based main component and adding SiO2 at 7.0 mol% or more with respect to 100 mol of Ti in the main component, a uniform non-grain growth boundary of dielectric crystal grains can be realized. As a result, effects such as a decrease in DF (Dissipation Factor) and the effective capacitance change rate, and an improvement in the breakdown voltage can be ensured, and the reliability of multilayer electronic components can be improved.

[0026] Hereinafter, each component of the dielectric composition according to an embodiment of the present invention will be described more specifically.

[0027] a) Main component The dielectric composition according to an embodiment of the present invention can include a main component represented by BaTiO3.

[0028] According to an embodiment of the present invention, the main component is BaTiO3, (Ba 1-x Ca x )(Ti 1-y Ca y )O3 (where x is 0 ≦ x ≦ 0.3 and y is 0 ≦ y ≦ 0.1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3 (where x is 0 ≦ x ≦ 0.3 and y is 0 ≦ y ≦ 0.5), and Ba(Ti 1-y Zr y )O3 (where 0 < y ≦ 0.5), and includes one or more selected from the group consisting of, but is not necessarily limited thereto.

[0029] In particular, when the dielectric layer is thinly formed to a thickness of less than 0.6 μm in response to the needs for miniaturization and high capacity, generally, fine powder of 100 nm or less is used, and the smaller the size of the powder, the greater the driving force for grain growth. As a result, the possibility of abnormal grain growth occurring becomes high, and it becomes difficult to obtain a uniform microstructure.

[0030] However, when a large amount of liquid elements are added as described later, by simultaneously and multiply inducing abnormal grain growth, a uniform microstructure can be ensured by uniform grain growth due to grain impingement rather than selective growth of some particles.

[0031] Therefore, when the average particle size of the main component powder is 100 nm or less, the effect of realizing a uniform non-grain growth boundary according to the present invention can be made more effective.

[0032] b) The first sub-component According to an embodiment of the present invention, the dielectric composition contains BaCO3 and SiO2 as the first sub-component elements. The BaCO3 is 4.0 mol% or more with respect to 100 moles of Ti as the main component, and the content of SiO2 is 7.0 mol% or more with respect to 100 moles of Ti as the main component. By adding an excessive amount of BaCO3 and SiO2, which are liquid-forming elements, the grain growth behavior due to temperature becomes gentle, the firing window can be widened, and by simultaneously and multiply inducing abnormal grain growth, grain impingement can ensure uniform grain growth rather than the growth of selectively partial particles.

[0033] Thereby, a uniform non-grain growth boundary of dielectric crystal grains can be realized, and the reliability of the multilayer electronic component can be improved by ensuring effects such as a decrease in DF (Dissipation Factor) and the change rate of effective capacitance, and an improvement in breakdown voltage.

[0034] When the content of BaCO3 is less than 4.0 mol% with respect to 100 moles of Ti as the main component, or the content of SiO2 is less than 7.0 mol% with respect to 100 moles of Ti as the main component, the effect of inducing abnormal grain growth is insufficient, so grain impingement may be insufficient, and it may be difficult to ensure a uniform fine structure.

[0035] Also, when BaCO3 and SiO2 satisfy the above content range, among the plurality of dielectric crystal grains contained in the dielectric layer after sintering, the number ratio of dielectric crystal grains with a size of 100 to 250 nm may be 55% or more.

[0036] In one embodiment, the content of the above BaCO3 is 4.0 mol% or more and 5.0 mol% or less with respect to 100 mol of Ti as the main component, and the content of the above SiO2 may be 7.0 mol% or more and 9.5 mol% or less with respect to 100 mol of Ti as the main component. Thereby, reliability can be improved and a high dielectric constant can be ensured.

[0037] When the content of BaCO3 exceeds 5.0 mol% with respect to 100 mol of Ti as the main component, or the content of SiO2 exceeds 9.5 mol% with respect to 100 mol of Ti as the main component, a more uniform microstructure can be ensured, but the dielectric constant may decrease, leading to a possibility of insufficient capacitance in the MLCC.

[0038] Further, when BaCO3 and SiO2 satisfy the above content range, among the plurality of dielectric crystal grains contained in the dielectric layer after sintering, the number ratio of the dielectric crystal grains with a size of 100 to 250 nm can be 55% to 65%.

[0039] On the other hand, the room temperature dielectric constant of the dielectric composition according to one embodiment of the present invention does not particularly need to be limited. For example, the room temperature dielectric constant may be 2000 or more.

[0040] c) Second sub-component According to one embodiment of the present invention, the dielectric composition may contain, as the second sub-component, an oxide or a carbonate containing at least one or more of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn.

[0041] As the above second sub-component, the oxide or carbonate containing at least one or more of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn can be contained in a content of 0.1 to 2.0 mol with respect to 100 mol of Ti as the main component.

[0042] The above second sub-component plays a role in lowering the firing temperature of the multilayer ceramic capacitor to which the dielectric composition is applied and improving the high-temperature withstand voltage characteristics.

[0043] The content of the second secondary component is the amount contained per 100 moles of Ti of the main component, and can be particularly defined as the moles of metal ions contained in each secondary component.

[0044] When the content of the second secondary component is less than 0.1 mole, the firing temperature becomes high, and the high-temperature breakdown voltage characteristics can be somewhat deteriorated.

[0045] When the content of the second secondary component is 2.0 moles or more, the high-temperature breakdown voltage characteristics and the room-temperature specific resistance can be deteriorated.

[0046] In particular, since the dielectric composition according to an embodiment of the present invention can include a second secondary component having a content of 0.1 to 2.0 moles per 100 moles of the main component, low-temperature firing is possible and high high-temperature breakdown voltage characteristics can be obtained.

[0047] d) Third secondary component According to an embodiment of the present invention, the dielectric porcelain composition can include a third secondary component including one or more selected from the group consisting of oxides and carbonates of one or more of Y, Dy, Ho, Sm, Gd, Er, La, Ce, Tb, Tm, Yb, and Nd.

[0048] The third secondary component can contain 4.0 moles or less per 100 moles of Ti of the main component.

[0049] The content of the third secondary component can be based on the content of at least one of Y, Dy, Ho, Sm, Gd, Er, La, Ce, Tb, Tm, Yb, and Nd contained in the third secondary component without distinguishing the addition form such as an oxide or a carbonate.

[0050] For example, the total content of at least one of Y, Dy, Ho, Sm, Gd, Er, La, Ce, Tb, Tm, Yb, and Nd contained in the third secondary component may be 4.0 moles or less per 100 moles of Ti of the main component.

[0051] In one embodiment of the present invention, the third subcomponent plays a role in preventing a decrease in reliability of a multilayer ceramic capacitor to which the dielectric ceramic composition is applied.

[0052] If the content of the third minor component exceeds 4.0 moles relative to 100 moles of Ti, the main component, high-temperature withstand voltage characteristics may be degraded due to the generation of a secondary phase of pyrochlore (RE2Ti2O7) (wherein RE is at least one element selected from the group consisting of Y, Dy, Ho, Sm, Gd, Er, La, Ce, and Nd).

[0053] e) Fourth subcomponent According to one embodiment of the present invention, the dielectric composition may include an oxide containing Al as a fourth minor component.

[0054] The dielectric composition may further contain 0.5 moles or less of a fourth minor component which is an oxide containing Al per 100 moles of Ti of the main component.

[0055] The content of the fourth minor component may be based on the content of Al element contained in the fourth minor component, regardless of the addition form such as glass, oxide, or carbonate.

[0056] The fourth subcomponent serves to lower the firing temperature of the multilayer ceramic capacitor to which the dielectric composition is applied and to improve the high-temperature withstand voltage characteristics.

[0057] If the content of the fourth subcomponent exceeds 0.5 moles per 100 moles of the main component, problems such as a decrease in sinterability and density and the generation of secondary phases may occur, which is not preferable.

[0058] [Multilayer electronic components] FIG. 1 is a schematic perspective view of a multilayer electronic component according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along line II' in FIG. FIG. 3 schematically shows a cross-sectional view taken along line II-II' of FIG. 1. FIG. 4 is an exploded perspective view schematically showing the decomposition of the main body of a multilayer electronic component according to an embodiment of the present invention.

[0059] Hereinafter, with reference to FIGS. 1 to 4, a multilayer electronic component according to an embodiment of the present invention will be described in detail. However, overlapping descriptions will be omitted to avoid redundancy with the content described in the above dielectric composition. In addition, a multilayer ceramic capacitor will be described as an example of the multilayer electronic component, but the present invention can also be applied to various electronic products using the above dielectric composition, such as inductors, piezoelectric elements, varistors, or thermistors.

[0060] A multilayer electronic component 100 according to an embodiment of the present invention includes a main body 110 including dielectric layers 111 and internal electrodes 121 and 122 alternately arranged with the dielectric layers, and external electrodes 131 and 132 arranged on the main body. Among the plurality of dielectric crystallites included in the dielectric layer, the number ratio of dielectric crystallites having a size of 100 to 250 nm is 55% or more.

[0061] In the main body 110, the dielectric layers 111 and the internal electrodes 121 and 122 are alternately laminated. There is no particular limitation on the specific shape of the main body 110, but as shown in the figure, the main body 110 can have a hexahedron shape or a shape similar thereto. Due to the shrinkage of the ceramic powder included in the main body 110 during the firing process, the main body 110 does not have a perfect hexahedron shape with straight lines, but can have a substantially hexahedron shape.

[0062] The main body 110 can have a first and a second surface (1, 2) facing each other in a first direction, a third and a fourth surface (3, 4) connected to the first and second surfaces (1, 2) and facing each other in a second direction, and a fifth and a sixth surface (5, 6) connected to the first and second surfaces (1, 2), connected to the third and fourth surfaces (3, 4), and facing each other in a third direction.

[0063] 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 so difficult to confirm without using a scanning electron microscope (SEM).

[0064] The dielectric layer 111 may be formed using the above-described dielectric composition.

[0065] Among the plurality of dielectric crystallites included in the dielectric layer 111, the number ratio of the dielectric crystallites having a size of 100 to 250 nm is 55% or more. Thereby, effects such as a decrease in the DF (Dissipation Factor) and the effective capacitance change rate, and an improvement in the breakdown voltage can be ensured, and the reliability of the multilayer electronic component can be improved.

[0066] When the number ratio of the dielectric crystallites having a size of 100 to 250 nm is less than 55%, the microstructure may be non-uniform and the reliability may decrease.

[0067] The number ratio of the dielectric crystallites having a size of 100 to 250 nm can be measured from an image scanned with a scanning electron microscope (SEM, Scanning Electron Microscope) at the center in the first and second directions of a cross section cut in the first and second directions from the center in the third direction of the body.

[0068] Specifically, in an image scanned at a magnification of 50k using an SEM of ZEISS, the Feret diameter of each dielectric crystallite measured using Zootos, which is particle size measurement software, was taken as the size of the dielectric crystallite, and the size distribution of the dielectric crystallites was analyzed.

[0069] In one embodiment, among the plurality of dielectric crystallites included in the dielectric layer 111, the number ratio of the dielectric crystallites having a size of 100 to 250 nm may be 55% to 65%. Thereby, the reliability can be improved and a high dielectric constant can be ensured.

[0070] When the percentage of the number of dielectric crystallites with a size of 100 to 250 nm exceeds 65%, the dielectric constant may decrease.

[0071] On the other hand, the thickness (td) of the dielectric layer 111 does not need to be particularly limited. However, generally when the dielectric layer is formed thinly with a thickness of less than 0.6 μm, especially when the thickness of the dielectric layer is 0.45 μm or less, there is a risk of reduced reliability.

[0072] As described above, according to one embodiment of the present invention, since effects such as a decrease in DF (Dissipation Factor) and the change rate of effective capacitance, and an improvement in breakdown voltage can be ensured, excellent reliability can be ensured even when the thickness of the dielectric layer 111 is 0.45 μm or less.

[0073] Therefore, when the thickness of the dielectric layer 111 is 0.45 μm or less, the effect of improving the reliability according to the present invention can be made more remarkable.

[0074] The thickness (td) of the dielectric layer 111 can mean the average thickness of the dielectric layer 111 disposed between the first and second internal electrodes 121 and 122.

[0075] The average thickness of the dielectric layer 111 can be measured by scanning an image of a cross-section in the length and thickness directions (L-T) of the main body 110 with a scanning electron microscope (SEM).

[0076] For example, for an arbitrary dielectric layer extracted from an image scanned with a scanning electron microscope (SEM) of a cross-section in the first and second directions (length and thickness directions) cut from the central portion in the third direction (width direction) of the main body 110, the thickness can be measured at 30 points at equal intervals in the length direction and the average value can be measured.

[0077] The thickness measured at the 30 equally spaced points can be measured from the capacitance forming portion (A) which means the region where the first and second internal electrodes 121 and 122 overlap each other.

[0078] The main body 110 includes a capacitance forming portion (A) which is disposed inside the main body 110 and in which a capacitance is formed including a first internal electrode 121 and a second internal electrode 122 disposed to face each other with the dielectric layer 111 interposed therebetween, and cover portions 112 and 113 formed on the upper and lower portions of the capacitance forming portion (A) in the first direction.

[0079] Further, the capacitance forming portion (A) is a portion that contributes to the formation of the capacitance of the capacitor, and may be formed by repeatedly laminating a plurality of first and second internal electrodes 121 and 122 with the dielectric layer 111 interposed therebetween.

[0080] The cover portions 112 and 113 may include an upper cover portion 112 disposed on the upper portion of the capacitance forming portion (A) in the first direction and a lower cover portion 113 disposed on the lower portion of the capacitance forming portion (A) in the first direction.

[0081] The upper cover portion 112 and the lower cover portion 113 can be formed by laminating a single dielectric layer or two or more dielectric layers in the thickness direction on the upper and lower surfaces of the capacitance forming portion (A), and can basically play a role of preventing damage to the internal electrodes due to physical or chemical stress.

[0082] The upper cover portion 112 and the lower cover portion 113 do not include internal electrodes and can include the same material as the dielectric layer 111.

[0083] That is, the upper cover portion 112 and the lower cover portion 113 can include a ceramic material, for example, a barium titanate (BaTiO3)-based ceramic material.

[0084] On the one hand, the thickness of the cover parts 112 and 113 does not need to be particularly limited. However, in order to more easily achieve miniaturization and high capacitance of the multilayer electronic component, the thickness (tp) of the cover parts 112 and 113 may be 20 μm or less.

[0085] Also, margin parts 114 and 115 may be arranged on the side surfaces of the capacitance forming part (A).

[0086] The margin parts 114 and 115 can include a margin part 114 arranged on the fifth surface (5) of the main body 110 and a margin part 115 arranged on the sixth surface (6). That is, the margin parts 114 and 115 may be arranged on both side surfaces in the width direction of the ceramic main body 110.

[0087] As shown in FIG. 3, the margin parts 114 and 115 can mean the regions between both ends of the first and second internal electrodes 121 and 122 and the boundary surface of the main body 110 in the cross section obtained by cutting the main body 110 in the width-thickness (W-T) direction.

[0088] Basically, the margin parts 114 and 115 can play a role in preventing damage to the internal electrodes due to physical or chemical stress.

[0089] The margin parts 114 and 115 may be formed by applying a conductive paste to form internal electrodes except for the locations where the margin parts are formed on the ceramic green sheet.

[0090] Also, in order to suppress the step difference caused by the internal electrodes 121 and 122, after laminating and then cutting so that the internal electrodes are exposed on the fifth and sixth surfaces (5, 6) of the main body, a single dielectric layer or two or more dielectric layers are laminated in the width direction (the third direction) on both side surfaces of the capacitance forming part (A) to form the margin parts 114 and 115.

[0091] The internal electrodes 121 and 122 are alternately laminated with the dielectric layer 111. The internal electrodes 121 and 122 can include the first and second internal electrodes 121 and 122. The first and second internal electrodes 121 and 122 are alternately arranged so as to face each other with the dielectric layer 111 constituting the main body 110 interposed therebetween, and can be respectively exposed on the third and fourth surfaces (3, 4) of the main body 110.

[0092] Referring to FIG. 2, the first internal electrode 121 can be exposed on the third surface (3) at a distance from the fourth surface (4), and the second internal electrode 122 can be exposed on the fourth surface (4) at a distance from the third surface (3).

[0093] At this time, the first and second internal electrodes 121 and 122 can be electrically separated from each other by the dielectric layer 111 disposed in the middle.

[0094] Referring to FIG. 4, the main body 110 can be formed by alternately laminating a ceramic green sheet printed with the first internal electrode 121 and a ceramic green sheet printed with the second internal electrode 122, and then firing.

[0095] The material for forming the internal electrodes 121 and 122 is not particularly limited, and a material having excellent electrical conductivity can be used. For example, the internal electrodes 121 and 122 can include any one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

[0096] Further, the internal electrodes 121 and 122 can be formed by printing a conductive paste for internal electrodes containing any one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof on a ceramic green sheet. As the printing method of the conductive paste for internal electrodes, a screen printing method, a gravure printing method, or the like can be used, but the present invention is not limited thereto.

[0097] On the other hand, the thickness (te) of the internal electrodes 121 and 122 does not need to be particularly limited. However, generally when the internal electrode is formed thin to a thickness of less than 0.6 μm, particularly when the thickness of the internal electrode is 0.45 μm or less, there is a risk of deterioration in reliability.

[0098] As described above, according to one embodiment of the present invention, since effects such as a decrease in DF (Dissipation Factor) and the rate of change of effective capacitance and an improvement in breakdown voltage can be ensured, excellent reliability can be ensured even when the thickness of the internal electrodes 121 and 122 is 0.45 μm or less.

[0099] Therefore, when the thickness of the internal electrodes 121 and 122 is 0.45 μm or less, the effects according to the present invention can be made more remarkable, and miniaturization and high capacitance of the multilayer electronic component can be more easily achieved.

[0100] The thickness (te) of the internal electrodes 121 and 122 can mean the average thickness of the internal electrodes 121 and 122.

[0101] The average thickness of the internal electrodes 121 and 122 can be measured by scanning an image of a cross-section in the length and thickness directions (L-T) of the main body 110 with a scanning electron microscope (SEM).

[0102] For example, for any first and second internal electrodes 121 and 122 extracted from an image scanned with a scanning electron microscope (SEM) of cross-sections in the first and second directions (length and thickness directions) cut from the central portion in the third direction (width direction) of the main body 110, the thickness can be measured at 30 points equally spaced in the length direction.

[0103] The 30 equally spaced points can be measured from the capacitance forming portion (A) meaning the region where the internal electrodes 121 and 122 overlap each other.

[0104] The external electrodes 131 and 132 may be disposed on the third surface (3) and the fourth surface (4) of the main body 110.

[0105] The external electrodes 131 and 132 may be respectively disposed on the third and fourth surfaces (3, 4) of the main body 110, and may include first and second external electrodes 131 and 132 respectively connected to the first and second internal electrodes 121 and 122.

[0106] Referring to FIG. 1, the external electrodes 131 and 132 may be disposed so as to cover both end faces in the second direction of the side margin portions 114 and 115.

[0107] In the present embodiment, a structure in which the multilayer electronic component 100 has two external electrodes 131 and 132 is described. However, the number, shape, etc. of the external electrodes 131 and 132 can be changed according to the form of the internal electrodes 121 and 122 and other purposes.

[0108] On the other hand, as long as the external electrodes 131 and 132 have electrical conductivity such as metal, any material can be used to form them, and a specific material can be determined in consideration of electrical characteristics, structural stability, etc., and they can further have a multilayer structure.

[0109] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a disposed on the main body 110 and plating layers 131b and 132b formed on the electrode layers 131a and 132a.

[0110] To give a more specific example of the electrode layers 131a and 132a, the electrode layers 131a and 132a may be fired electrodes including conductive metal and glass, or resin-based electrodes including conductive metal and resin.

[0111] In addition, the electrode layers 131a and 132a may be in a form in which a fired electrode and a resin-based electrode are sequentially formed on the main body. Further, the electrode layers 131a and 132a may be formed by a method of transferring a sheet containing a conductive metal onto the main body, or may be formed by a method of transferring a sheet containing a conductive metal onto a fired electrode.

[0112] As the conductive metal contained in the electrode layers 131a and 132a, a material having excellent electrical conductivity can be used, but it is not particularly limited. For example, the conductive metal may be any one or more of nickel (Ni), copper (Cu), and alloys thereof.

[0113] The plating layers 131b and 132b serve to improve the mounting characteristics. The types of the plating layers 131b and 132b are not particularly limited, and may be plating layers containing one or more of Ni, Sn, Pd, and alloys thereof, and may be formed of a plurality of layers.

[0114] More specific examples of the plating layers 131b and 132b are as follows. The plating layers 131b and 132b may be Ni plating layers or Sn plating layers, and may be in a form in which a Ni plating layer and an Sn plating layer are sequentially formed on the electrode layers 131a and 132a, or may be in a form in which an Sn plating layer, a Ni plating layer, and an Sn plating layer are sequentially formed. Further, the plating layers 131b and 132b may also include a plurality of Ni plating layers and / or a plurality of Sn plating layers.

[0115] The size of the multilayer electronic component 100 does not need to be particularly limited. However, in order to simultaneously achieve miniaturization and high capacitance, it is necessary to reduce the thickness of the dielectric layer and the internal electrodes and increase the number of layers. Therefore, in the multilayer electronic component 100 having a size of 0402 (length × width, 0.4 mm × 0.2 mm) or less, the effects of improving the reliability and insulation resistance according to the present invention can be made more remarkable.

[0116] Therefore, considering manufacturing errors, the size of the external electrodes, etc., when the length of the multilayer electronic component 100 is 0.44 mm or less and the width is 0.22 mm or less, the effect of improving the reliability according to the present invention can be made more remarkable. Here, the length of the multilayer electronic component 100 means the maximum size in the second direction of the multilayer electronic component 100, and the width of the multilayer electronic component 100 can mean the maximum size in the third direction of the multilayer electronic component 100.

[0117] [Embodiment] An embodiment of the present invention includes barium titanate (BaTiO3) as a main component, and after preparing a dielectric composition having the contents described in Table 1 below with respect to 100 mol of Ti of the above main components for BaCO3 and SiO2, a prototype multilayer ceramic capacitor (Proto-type MLCC) in which a dielectric layer is formed using a ceramic green sheet containing the above dielectric composition was provided.

[0118] For Test Nos. 1 to 4 of the prototype multilayer ceramic capacitor (Proto-type MLCC) completed as described above, the dielectric constant, DF, and effective capacitance change rate were measured and described in Table 1 below.

[0119] The effective capacitance and DF are measured values using a measuring instrument, and the dielectric constant is a value converted from the thickness of the dielectric and the size of the dielectric crystal grains.

[0120]

Table 1

[0121] In the case of Test No. 1, it can be confirmed that the content of BaCO3 is less than 4.0 mol% and the content of SiO2 is less than 7.0 mol%, and the DF and the effective capacitance change rate are large, and the reliability is poor.

[0122] On the other hand, in the case of Test Nos. 2 to 4, it can be confirmed that the content of BaCO3 is 4.0 mol% or more and the content of SiO2 is 7.0 mol% or more, and the DF and the effective capacitance change rate are small, and the reliability is excellent.

[0123] However, in the case of test number 4, the dielectric constant was slightly low at 1300. Therefore, in order to ensure a high dielectric constant while improving reliability, the content of BaCO3 is preferably 4.0 mol% or more and 5.0 mol% or less with respect to 100 mol of Ti as the main component, and the content of SiO2 is preferably 7.0 mol% or more and 9.5 mol% or less with respect to 100 mol of Ti as the main component.

[0124] Figure 5 is an image obtained by scanning the central portions in the first and second directions of a cross-section cut in the first and second directions from the center in the third direction of a sample chip of test number 1 at a magnification of 50k using a SEM of ZEISS. Figure 6 is a photograph for measuring the Feret diameter of each dielectric crystal grain using Zootos, which is particle size measurement software, and Figure 7 is a graph analyzing the size distribution of each dielectric crystal grain measured using Zootos.

[0125] Figures 8 to 10 are graphs analyzing the size distribution of dielectric crystal grains for test numbers 2 to 4, and are graphs obtained by analyzing by the method as shown in Figure 7.

[0126] Referring to Figures 7 to 10, it can be confirmed that as the contents of BaCO3 and SiO2 increase, the size distribution of the dielectric crystal grains gradually becomes more uniform and smaller.

[0127] Also, considering the results in Table 1 above comprehensively, it can be seen that from the perspective of improving reliability, it is preferable that the percentage of the number of dielectric crystal grains with a size of 100 to 250 nm among a plurality of dielectric crystal grains is 55% or more. Also, when the percentage of the number of dielectric crystal grains with a size of 100 to 250 nm among a plurality of dielectric crystal grains is 55%, it can be confirmed that reliability can be improved and a high dielectric constant can be ensured.

[0128] As described above in detail for the embodiments of the present invention, the present invention is not limited by the above-described embodiments and the attached drawings, but is limited by the attached claims. Therefore, within the scope not departing from the technical idea of the present invention described in the claims, various forms of substitution, modification, and change are possible by those having ordinary knowledge in the art, and it can be said that these also belong to the scope of the present invention.

Explanation of Reference Numerals

[0129] 100: Multilayer electronic component 110: Body 111: Dielectric layer 112, 113: Cover part 114, 115: Side margin part 121, 122: Internal electrode 131, 132: External electrode 131a: Electrode layer 132b: Plating layer

Claims

1. A body including a dielectric layer and internal electrodes alternately arranged with the dielectric layer, and an external electrode disposed on the body, wherein, among a plurality of dielectric crystallites included in the dielectric layer, the number ratio of dielectric crystallites having a size of 100 to 250 nm is 55% or more, the dielectric layer has a dielectric composition including a main component and a first sub-component of a BaTiO₃ system, The first sub-component contains BaCO ３ and SiO₂, the BaCO₃ is 4.0 mol% or more with respect to 100 mol of Ti of the main component, the content of the SiO₂ is 7.0 mol% or more with respect to 100 mol of Ti of the main component, a multilayer electronic component.

2. The multilayer electronic component according to claim 1, wherein, among a plurality of dielectric crystallites included in the dielectric layer, the number ratio of dielectric crystallites having a size of 100 to 250 nm is 55% to 65%.

3. The dielectric layer has a dielectric composition containing a main component and a first sub-component of the BaTiO ３ system, The first sub-component contains BaCO ３ and SiO ２ and The content of the BaCO ３ is 4.0 mol% or more and 5.0 mol% or less with respect to 100 mol of Ti of the main component, The content of the SiO ２ is 7.0 mol% or more and 9.5 mol% or less with respect to 100 mol of Ti as the main component. The multilayer electronic component according to claim 2.

4. the dielectric composition further includes a second sub-component, the second sub-component includes an oxide or carbonate including at least one or more of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn, and is included in an amount of 0.1 to 2.0 mol with respect to 100 mol of Ti of the main component, the multilayer electronic component according to claim 1 or 3.

5. the dielectric composition includes a third sub-component, the third sub-component includes at least one or more elements of Y, Dy, Ho, Sm, Gd, Er, La, Ce, Tb, Tm, Yb, and Nd, and the content of the third sub-component is 4.0 mol or less with respect to 100 mol of Ti of the main component, the multilayer electronic component according to claim 4.

6. the dielectric composition includes a fourth sub-component, the fourth sub-component includes an oxide including Al, and the content of the fourth sub-component is 0.5 mol or less with respect to 100 mol of Ti of the main component, the multilayer electronic component according to claim 5.

7. The multilayer electronic component according to any one of claims 1 to 6, wherein the average thickness of the dielectric layer is 0.45 μm or less.

8. The multilayer electronic component according to any one of claims 1 to 7, wherein the average thickness of the internal electrode is 0.45 μm or less.

9. BaTiO ３ including the main component and the first sub-component of the system, The first sub-component contains BaCO ３ and SiO ２ and The above-mentioned BaCO ３ is 4.0 mol% or more with respect to 100 mol of Ti as the main component, The SiO ２ content is 7.0 mol% or more with respect to 100 mol of Ti as the main component in the dielectric composition.

10. The content of the BaCO ３ is 4.0 mol% or more and 5.0 mol% or less with respect to 100 mol of Ti of the main component, The content of the SiO ２ is 7.0 mol% or more and 9.5 mol% or less with respect to 100 mol of Ti as the main component. The dielectric composition according to claim 9.

11. The dielectric composition according to claim 9 or 10, wherein the average particle size of the powder of the main component is 100 nm or less.

12. the dielectric composition further includes a second sub-component, The second sub-component contains an oxide or carbonate containing at least one or more of Mn, V, Cr, Fe, Ni, Co, Cu, and Zn, and contains the same in an amount of 0.1 to 2.0 moles with respect to 100 moles of Ti of the main component. The dielectric composition according to any one of claims 9 to 11.

13. The dielectric composition contains a third sub-component, The third sub-component contains at least one or more elements of Y, Dy, Ho, Sm, Gd, Er, La, Ce, Tb, Tm, Yb, and Nd, and the content of the third sub-component is 4.0 moles or less with respect to 100 moles of Ti of the main component. The dielectric composition according to claim 12.

14. The dielectric composition contains a fourth sub-component, The fourth sub-component contains an oxide containing Al, and the content of the fourth sub-component is 0.5 moles or less with respect to 100 moles of Ti of the main component. The dielectric composition according to claim 13.

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