Laminate type electronic component

Abstract

To provide a laminate type electronic component that relieves a problem of deterioration in moisture resistance reliability of the laminate type electronic component that occurs due to the decrease in a moisture resistance permeation path.SOLUTION: A laminate type electronic component includes: a dielectric layer 111; internal electrodes 121 and 122 disposed alternately with the dielectric layer in a first direction; a lamination part 110 having a first surface and a second surface which face each other in the first direction, a third surface and a fourth surface which face each other in a second direction that is perpendicular to the first direction and is coupled to at least a part of the internal electrodes, and a fifth surface and a sixth surface which face each other in a third direction that is perpendicular to the first direction and the second direction; a protection part 120 disposed on the third surface and the fourth surface; and external electrodes 131 and 132 disposed on the lamination part and the protection part and coupled to the internal electrodes. The dielectric layer includes a first dielectric crystal grain and the protection part includes a second dielectric crystal grain. An average size of the second dielectric crystal grains may be smaller than an average size of the first dielectric crystal grains.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a multilayer electronic component. [Background technology]

[0002] Multi-layered ceramic capacitors (MLCCs), a type of multilayer electronic component, are chip-type capacitors that are mounted on printed circuit boards of various electronic products, such as visual devices such as liquid crystal displays (LCDs) and plasma display panels (PDPs), computers, smartphones, and mobile phones, and serve to charge and discharge electricity.

[0003] Multilayer ceramic capacitors have advantages of being small in size, having high capacitance, and being easy to mount, and can be used as components of various electronic devices. As various electronic devices such as computers and mobile devices become smaller and have higher output, there is an increasing demand for smaller multilayer ceramic capacitors with higher capacitance.

[0004] In order to increase the capacitance per unit volume of a multilayer ceramic capacitor, a method of maximizing the area occupied by the capacitance-forming portion of the entire component can be used. In this case, the thickness of the cover portion or margin portion disposed on the top, bottom, or both sides of the capacitance-forming portion may be reduced, which may cause a problem of reducing the moisture resistance reliability of the multilayer electronic component.

[0005] Furthermore, if the margins of the multilayer ceramic capacitor are minimized, a portion of the internal electrodes may be exposed on a surface other than the surface on which the external electrodes are applied during the polishing process of the laminated portion, which may cause a short circuit in the multilayer ceramic capacitor.

[0006] Therefore, there is a need for a structural improvement that can alleviate the problem of deterioration in moisture resistance reliability of multilayer ceramic capacitors caused by a reduction in moisture-resistant penetration paths and the problem of short circuits occurring in multilayer ceramic capacitors due to the minimal formation of margin portions. Summary of the Invention [Problem to be solved by the invention]

[0007] One of several objects of the present invention is to alleviate the problem of deterioration in moisture resistance reliability of multilayer electronic components caused by a reduction in moisture-resistant penetration paths.

[0008] One of several objects of the present invention is to alleviate the problem of short circuits occurring in laminated electronic components due to the minimal formation of margins.

[0009] However, the object of the present invention is not limited to the above-mentioned contents, and can be more easily understood in the course of describing specific embodiments of the present invention. [Means for solving the problem]

[0010] A multilayer electronic component according to one embodiment of the present invention includes: a laminated portion including dielectric layers, internal electrodes arranged alternately with the dielectric layers in a first direction, first and second surfaces facing the first direction, third and fourth surfaces facing a second direction perpendicular to the first direction and connected to at least a portion of the internal electrodes, and fifth and sixth surfaces facing a third direction perpendicular to the first and second directions; protective portions arranged on the third and fourth surfaces; and external electrodes arranged on the laminated portion and the protective portions and connected to the internal electrodes, wherein the dielectric layers include first dielectric crystal grains, and the protective portion includes second dielectric crystal grains, and an average size of the second dielectric crystal grains is smaller than an average size of the first dielectric crystal grains. [Effects of the Invention]

[0011] One of the advantages of the present invention is that it extends the moisture-resistant penetration path, thereby improving the moisture-resistant reliability of the multilayer electronic component.

[0012] One of the effects of the present invention is that it compensates for under-formation of marginal portions, thereby reducing the incidence of short circuits in multilayer electronic components.

[0013] However, the various beneficial advantages and effects of the present invention are not limited to the above, and can be more easily understood in the course of describing specific embodiments of the present invention. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic perspective view of a multilayer electronic component according to an embodiment of the present invention; [Figure 2] 1 is a perspective view schematically illustrating a configuration of a multilayer electronic component according to an embodiment, excluding external electrodes. [Figure 3] 2 is a schematic cross-sectional view taken along line II' of FIG. 1. [Figure 4] 2 is a schematic cross-sectional view taken along line III-III' in FIG. 1. [Figure 5] 2 is a schematic cross-sectional view taken along line II-II' in FIG. 1. [Figure 6] FIG. 4 is an enlarged view of region P in FIG. 3. [Figure 7] 1 is a schematic diagram illustrating an exploded perspective view of a stack according to an embodiment. [Figure 8] 10 is a schematic diagram illustrating a coupling relationship between a laminated portion and a protective portion according to an embodiment. [Figure 9] 1 is a perspective view schematically illustrating a configuration of a multilayer electronic component according to an embodiment, excluding external electrodes. [Figure 10] 10 is a schematic diagram illustrating a coupling relationship between a laminated portion and a protective portion according to an embodiment. [Figure 11] 4 is a schematic cross-sectional view taken along line IV-IV′ of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and 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. Furthermore, 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 clarity, and elements designated by the same reference numerals in the drawings are the same elements.

[0016] In addition, in the drawings, parts that are not relevant to the description are omitted in order to clearly explain the present invention, and the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to those shown. Components that have the same function within the same conceptual scope will be described using the same reference numerals. Furthermore, throughout the specification, when a part is said to "include" a certain component, this does not mean that other components are excluded, but that other components may also be included, unless otherwise specified.

[0017] In the drawings, the first direction can be defined as the stacking direction or thickness T direction, the second direction can be defined as the length L direction, and the third direction can be defined as the width W direction.

[0018] 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 perspective view of a multilayer electronic component according to one example, excluding external electrodes, FIG. 3 is a schematic cross-sectional view taken along line I-I' in FIG. 1, FIG. 4 is a schematic cross-sectional view taken along line III-III' in FIG. 1, FIG. 5 is a schematic cross-sectional view taken along line II-II' in FIG. 1, FIG. 6 is an enlarged view of region P in FIG. 3, FIG. 7 is a schematic exploded perspective view of a multilayer section according to one example, FIG. 8 is a schematic view showing the connection between the multilayer section and the protective section according to one example, FIG. 9 is a schematic perspective view of a multilayer electronic component according to one example, excluding external electrodes, FIG. 10 is a schematic view showing the connection between the multilayer section and the protective section according to one example, and FIG. 11 is a schematic cross-sectional view taken along line IV-IV' in FIG.

[0019] A multilayer electronic component 100 according to one embodiment of the present invention and various embodiments thereof will be described in detail below with reference to Figures 1 to 11. Furthermore, a multilayer ceramic capacitor (hereinafter referred to as "MLCC") will be described as an example of the multilayer electronic component, but the present invention is not limited to this.

[0020] A multilayer electronic component 100 according to one embodiment of the present invention includes a laminate unit 110 including dielectric layers 111, internal electrodes 121, 122 arranged alternately with the dielectric layers in a first direction, first and second surfaces 1, 2 facing the first direction, third and fourth surfaces 3, 4 facing a second direction perpendicular to the first direction and connected to at least a portion of the internal electrodes, and fifth and sixth surfaces 5, 6 facing a third direction perpendicular to the first and second directions, a protective portion 120 arranged on the third and fourth surfaces, and external electrodes 131, 132 arranged on the laminate unit and the protective portion and connected to the internal electrodes, wherein the dielectric layers include first dielectric crystal grains, and the protective portion includes second dielectric crystal grains, and the average size of the second dielectric crystal grains may be smaller than the average size of the first dielectric crystal grains.

[0021] Hereinafter, each component included in the multilayer electronic component 100 according to one embodiment of the present invention will be described.

[0022] The laminated portion 110 may include dielectric layers 111 and internal electrodes 121 and 122 alternately arranged with the dielectric layers 111 in a first direction.

[0023] Although there is no particular limitation on the specific shape of the laminated portion 110, as shown in the figure, the laminated portion 110 may have a hexahedral shape or a similar shape. Due to shrinkage of the ceramic powder contained in the laminated portion 110 during the firing process, the laminated portion 110 may have a substantially hexahedral shape, although not a hexahedral shape with perfectly straight lines.

[0024] In one embodiment, the stacking direction of the dielectric layers 111 and the internal electrodes 121 and 122 can be defined as a first direction, a direction perpendicular to the first direction as a second direction, and a direction perpendicular to the first and second directions as a third direction.

[0025] The laminated portion 110 may have a first surface 1 and a second surface 2 facing in a first direction, a third surface 3 and a fourth surface 4 connected to the first surface 1 and the second surface 2 and facing in the second direction, and a fifth surface 5 and a sixth surface 6 connected to the first surface 1 and the second surface 2, connected to the third surface 3 and the fourth surface 4, and facing in the third direction.

[0026] In this case, the third surface 3 and the fourth surface 4 may be connected to at least a portion of the internal electrodes 121 and 122. Specifically, the third surface 3 may be connected to the first internal electrode 121, and the fourth surface 4 may be connected to the second internal electrode 122.

[0027] In addition, the fifth surface 5 and the sixth surface 6 may be disposed apart from the internal electrodes 121 and 122. Specifically, the fifth surface 5 and the sixth surface 6 may be disposed apart from both ends of the first internal electrode 121 and the second internal electrode 122 in the third direction.

[0028] The overlap of the marginal regions where the internal electrodes 121 and 122 are not disposed on the dielectric layer 111 generates steps due to the thickness of the internal electrodes 121 and 122, and the corners connecting the first surface with the third surface, the fourth surface, and the fifth surface and / or the corners connecting the second surface with the third surface, the fourth surface, and the fifth surface may have a shape that shrinks toward the center in the first direction of the laminated unit 110 when viewed from the first surface or the second surface. Alternatively, due to shrinkage behavior during the sintering process of the laminated unit, the corners connecting the first surface 1 with the third surface 3, the fourth surface 4, the fifth surface 5, and the sixth surface 6 and / or the corners connecting the second surface 2 with the third surface 3, the fourth surface 4, the fifth surface 5, and the sixth surface 6 may have a shape that shrinks toward the center in the first direction of the laminated unit 110 when viewed from the first surface or the second surface. Alternatively, in order to prevent chipping defects, etc., the corners connecting each surface of the laminated portion 110 may be rounded through a separate process, so that the corners connecting the first surface with the third surface 3, the fourth surface 4, the fifth surface 5, and the sixth surface 6 and / or the corners connecting the second surface with the third surface 3, the fourth surface 4, the fifth surface 5, and the sixth surface 6 may have a rounded shape.

[0029] The multiple dielectric layers 111 that form the laminated section 110 are in a fired state, and the boundaries between adjacent dielectric layers 111 can be integrated to such an extent that they are difficult to see without the use of a scanning electron microscope (SEM). The number of laminated dielectric layers does not need to be particularly limited, and can be determined taking into account the size of the multilayer electronic component. For example, the laminated section can be formed by laminating 400 or more dielectric layers.

[0030] The dielectric layer 111 can be formed by manufacturing a ceramic slurry containing ceramic powder, an organic solvent, and a binder, applying and drying the slurry on a carrier film to provide a ceramic green sheet, and then firing the ceramic green sheet. The ceramic powder is not particularly limited as long as sufficient capacitance can be obtained. For example, a barium titanate (BaTiO3)-based powder can be used as the ceramic powder. More specifically, as the ceramic powder, a barium titanate (BaTiO3)-based ferroelectric powder, a CaZrO3-based normal dielectric powder, etc. can be used. More specifically, as the barium titanate (BaTiO3)-based powder, BaTiO3, (Ba 1-x Ca x )TiO3(0 < x < 1), Ba(Ti 1-y Ca y )O3(0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3(0 < x < 1, 0 < y < 1), and Ba(Ti 1-y Zr y )O3(0 < y < 1) may be one or more of them, and the CaZrO3-based normal dielectric powder may be (Ca 1-x Sr x )(Zr 1-y Ti y )O3(0 < x < 1, 0 < y < 1).

[0031] Therefore, the dielectric layer 111 is BaTiO3, (Ba 1-x Ca x )TiO3(0 < x < 1), Ba(Ti 1-y Ca y )O3(0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3(0 < x < 1, 0 < y < 1), Ba(Ti 1-y Zr y )O3(0 < y < 1), and (Ca 1-x Sr x )(Zr 1-y Ti y)It can contain one or more of O3 (0 < x < 1, 0 < y < 1).

[0032] The average thickness td of the dielectric layer 111 is not particularly limited.

[0033] When aiming for miniaturization and high capacitance of the multilayer electronic component 100, the average thickness td of the dielectric layer 111 may be 0.35 μm or less, and in order to improve the reliability of the multilayer electronic component 100 under high temperature and high pressure, the average thickness td of the dielectric layer 111 may be 3 μm or more.

[0034] The average thickness td of the dielectric layer 111 can be measured by scanning an image of a cross-section (L-T cross-section) in the third direction and the first direction of the stacked portion 110 with a scanning electron microscope (SEM).

[0035] For example, the average thickness td of the dielectric layer 111 is extracted from the dielectric layer in the image scanned by a scanning electron microscope (SEM) of the length and the cross-section in the thickness direction (L-T) cut at the central portion in the width direction of the stacked portion 110. Among the five dielectric layers, including two upper layers and two lower layers, with the dielectric layer at the point where the central line in the length direction of the stacked portion and the central line in the thickness direction meet as a reference, after determining five points, two on the left side and two on the right side, at equal intervals around one reference point, the thickness at each point is measured and the average value can be measured.

[0036] The stacked portion 110 can include a capacitance forming portion Ac in which the dielectric layer 111 and the internal electrodes 121 and 122 are alternately arranged to form a capacitance. Specifically, the capacitance forming portion Ac may be a region arranged inside the stacked portion 110 and including the first internal electrode 121 and the second internal electrode 122 arranged to face each other with the dielectric layer 111 interposed therebetween, where a capacitance is formed.

[0037] The capacitance forming portion Ac is a portion that contributes to forming the capacitance of the capacitor, and can be formed by repeatedly stacking a plurality of first internal electrodes 121 and second internal electrodes 122 with a dielectric layer 111 sandwiched therebetween. The first internal electrode 121 can be arranged at the uppermost end of the capacitance forming portion Ac in the first direction, and the second internal electrode 122 can be arranged at the lowermost end in the first direction.

[0038] The internal electrodes 121, 122 may include a first internal electrode 121 and a second internal electrode 122. The first internal electrodes 121 and the second internal electrodes 122 may be alternately arranged to face each other across the dielectric layer 111 constituting the multilayer unit 110, and may be connected to a third surface 3 and a fourth surface 4 of the multilayer unit 110, respectively.

[0039] The first internal electrode 121 may be spaced apart from the fourth surface 4 and connected to the third surface 3, and the second internal electrode 122 may be spaced apart from the third surface 3 and connected to the fourth surface 4. A first external electrode 131 may be disposed on the third surface 3 of the laminated portion and connected to the first internal electrode 121, and a second external electrode 132 may be disposed on the fourth surface 4 of the laminated portion and connected to the second internal electrode 122.

[0040] That is, the first internal electrode 121 is not connected to the second external electrode 132 but is connected to the first external electrode 131, and the second internal electrode 122 is not connected to the first external electrode 131 but is connected to the second external electrode 132. Therefore, the first internal electrodes 121 may be formed at a predetermined distance apart on the fourth surface 4, and the second internal electrodes 122 may be formed at a predetermined distance apart on the third surface 3.

[0041] The conductive metal contained in the internal electrodes 121, 122 may be one or more of Ni, Cu, Pd, Ag, Au, Pt, In, Sn, Al, Ti, and alloys thereof, but the present invention is not limited thereto.

[0042] The average thickness te of the internal electrodes 121, 122 is not particularly limited and may vary depending on the purpose. To reduce the size of the multilayer electronic component 100, the average thickness te of the internal electrodes 121, 122 may be 0.35 μm or less, and to improve the reliability of the multilayer electronic component 100 under high temperature and high pressure, the average thickness te of the internal electrodes 121, 122 may be 3 μm or more.

[0043] The average thickness te of the internal electrodes 121 and 122 can be calculated by measuring the thickness of each of five internal electrode layers, two upper and two lower, based on one internal electrode layer at a point where the center line of the length direction and the center line of the thickness direction of the laminated unit intersect, among the internal electrode layers extracted from an image obtained by scanning a cross section of the laminated unit 110 in a length and thickness direction (LT) using a scanning electron microscope (SEM). The five internal electrode layers are determined by measuring the thickness of each of five internal electrode layers, two upper and two lower, based on the point where the center line of the length direction and the center line of the thickness direction of the laminated unit intersect.

[0044] The shapes of the internal electrodes 121 and 122 are not particularly limited.

[0045] However, if the internal electrodes 121, 122 have a bottleneck shape in which the size in the third direction becomes smaller toward the third surface 3 or the fourth surface 4, the penetration path of moisture from the outside to the internal electrodes 121, 122 becomes longer, which can be advantageous in ensuring moisture resistance reliability.

[0046] On the other hand, when the internal electrodes do not have a bottleneck shape, it is possible to improve the capacitance per unit volume of the multilayer electronic component 100 and reduce the dispersion of the thickness of the internal electrodes, thereby improving the BDV characteristics. However, when the internal electrodes do not have a bottleneck shape, the penetration path for moisture from the outside becomes shorter than when a bottleneck shape is applied, which may make it difficult to ensure moisture resistance reliability.

[0047] However, according to one embodiment of the present invention, since protective portion 120 including dielectric crystal grains having an average crystal grain size smaller than that of dielectric layer 111 is formed on third surface 3 and fourth surface 4 of laminate portion 110, excellent moisture resistance reliability can be ensured even when a bottleneck pattern is not applied to the internal electrodes. That is, when a bottleneck pattern is not applied to the internal electrodes, the effect of improving moisture resistance reliability of the present invention can be further improved, and the capacitance per unit volume of multilayer electronic component 100 can be improved compared to when a bottleneck pattern is applied, and the BDV characteristics can also be improved.

[0048] Meanwhile, "when no bottleneck pattern is applied to the internal electrodes" may mean that the internal electrodes 121, 122 have a rectangular shape in the cross sections of the laminated part 110 in the second and third directions, or may mean that the sizes of the internal electrodes 121, 122 in the third direction are substantially the same along the second direction. In this case, "the sizes of the internal electrodes 121, 122 in the third direction are substantially the same along the second direction" may mean that the sizes of the internal electrodes 121, 122 in the third direction vary within a deviation range of -2% to +2% along the second direction.

[0049] Referring to FIGS. 3 and 5, cover portions C1 and C2 may be disposed on both sides of the capacitance forming portion Ac in the first direction.

[0050] The cover parts C1 and C2 basically serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0051] The cover portions C1 and C2 may include the same material as the dielectric layer 111. That is, the cover portions 112 and 113 may include a ceramic material, for example, a barium titanate (BaTiO3) based ceramic material.

[0052] Referring to FIG. 7, the cover portions C1 and C2 may be formed by stacking additional dielectric layers 111 on both sides of the capacitance forming portion in the first direction in which the internal electrodes 121 and 122 and the dielectric layers 111 are alternately arranged, but are not limited to this.

[0053] On the other hand, the thickness of the covers C1 and C2 does not need to be particularly limited. For example, the average thickness tc of the covers 112 and 113 may be 0.25 times or less the maximum size of the multilayer electronic component 100 in the first direction.

[0054] If the average thickness of the cover portions C1 and C2 is less than 0.25 times the maximum size in the first direction of each multilayer electronic component 100, the paths for external moisture or plating solution to penetrate into the cover portions C1 and C2 are reduced, which may make it difficult to ensure the moisture-resistant reliability of the multilayer electronic component 100. However, according to one embodiment of the present invention, the protective portion 120 is formed on the third surface 3 and the fourth surface 4 of the multilayer unit 110, and the protective portion 120 includes dielectric crystal grains having an average grain size smaller than that of the dielectric layer 111. This makes it possible to ensure excellent moisture-resistant reliability even when the average thickness of the cover portions C1 and C2 is less than 0.25 times the maximum size in the first direction of the multilayer electronic component 100. In other words, if the average thickness of the cover portions C1 and C2 is less than 0.25 times the maximum size in the first direction of the multilayer electronic component 100, the effect of improving the moisture-resistant reliability of the present invention may be even more significant.

[0055] The average thickness tc of the cover portions C1 and C2 may mean the average size in the first direction, and may be the average value of the size in the first direction of the cover portions C1 and C2 measured at five equally spaced points on the top or bottom of the capacitance forming portion Ac.

[0056] 4 and 5, margin portions M1 and M2 may be arranged on both sides of the capacitance forming portion Ac in the third direction.

[0057] The margin portions M1 and M2 may include a first margin portion M1 disposed on the fifth surface 5 of the laminated unit 110 and a second margin portion M2 disposed on the sixth surface 6. That is, the margin portions 114 and 115 may be disposed on both end surfaces of the ceramic laminated unit 110 in the width direction.

[0058] The margin portions 114 and 115 may refer to the regions between both ends of the first internal electrode 121 and the second internal electrode 122 and the boundary surface of the laminated portion 110 in a cross-section of the laminated portion 110 cut in the width-thickness (WT) direction, as shown in FIG. 5.

[0059] The margin portions M1 and M2 basically serve to prevent damage to the internal electrodes due to physical or chemical stress.

[0060] Margin portions M1 and M2 may be formed by applying a conductive paste to the ceramic green sheets to form internal electrodes except for the areas where the margin portions are to be formed, but are not limited to this. They may be formed by applying a ceramic slurry for forming margin portions to the side surfaces of the laminate portion 110 and then firing the applied paste, or by pressing and adhering ceramic green sheets for forming margin portions together and then firing the applied paste. The material for forming the first side margin portion 114 and the second side margin portion 115 is not particularly limited, and may be formed of the same material as the dielectric layer 111, but is not limited to this. They may be formed of a different material from the dielectric layer 111, resulting in different compositions.

[0061] On the other hand, the widths of the margins M1 and M2 do not need to be particularly limited. For example, the average width of each of the margins M1 and M2 may be 0.25 times or less the maximum size of the multilayer electronic component 100 in the third direction.

[0062] If the average widths of the margin portions M1 and M2 are each 0.25 times or less the maximum size in the third direction of the multilayer electronic component 100, the number of paths through which external moisture or plating solution can penetrate the margin portions M1 and M2 may be reduced, potentially making it difficult to ensure the moisture-resistant reliability of the multilayer electronic component 100. However, according to one embodiment of the present invention, the protective portion 120 is formed on the third surface 3 and the fourth surface 4 of the multilayer unit 110, and the protective portion 120 includes dielectric crystal grains having an average grain size smaller than that of the dielectric layer 111. This makes it possible to ensure excellent moisture-resistant reliability even when the average widths of the margin portions M1 and M2 are each 0.25 times or less the maximum size in the third direction of the multilayer electronic component 100. In other words, if the average widths of the margin portions M1 and M2 are each 0.25 times or less the maximum size in the third direction of the multilayer electronic component 100, the effect of improving the moisture-resistant reliability of the present invention may be even more significant.

[0063] The average width of the margin portions M1 and M2 may mean the average size in the third direction of the region where the internal electrode is separated from the fifth surface and the average size in the third direction of the region where the internal electrode is separated from the sixth surface, and may be the average value of the sizes in the third direction of the margin portions M1 and M2 measured at five equally spaced points on the side of the capacitance forming portion Ac.

[0064] 8, a protective part 120 may be disposed on the third and fourth surfaces 3 and 4 of the laminated part 110. The protective part 120 is disposed on the third and fourth surfaces 3 and 4 connected to one ends of the internal electrodes 121 and 122, and may serve to increase the penetration path of moisture from the outside.

[0065] The material for forming the protective portion 120 is not particularly limited, but the protective portion 120 may be formed of BaTiO3, (Ba 1-x Ca x )TiO3(0 <x<1)、Ba(Ti 1-y Ca y )O3(0 <y<1)、(Ba 1-x Ca x )(Ti 1-y Zr y )O3(0 <x<1、0<y<1)、Ba(Ti 1-y Zr y)O3 (0 < y < 1) and (Ca 1-x Sr x )(Zr 1-y Ti y )O3 (0 < x < 1, 0 < y < 1) can include one or more dielectric materials.

[0066] According to an embodiment of the present invention, the stacked portion 110 can include dielectric crystallites. Since only the dielectric layer exists in the cover portion or the margin portion, which is a region without an internal electrode in the stacked portion 110, the sintering driving force may be weaker than that of the capacitance forming portion Ac including the internal electrode. As a result, when the stacked portion 110 is sintered, the cover portion or the margin portion may form a less dense structure than the capacitance forming portion Ac.

[0067] Therefore, in one embodiment of the present invention, a protective portion 120 having dielectric crystallites finer than the dielectric layer 111 is formed on the third and fourth surfaces 3 and 4 of the stacked portion 110 to increase the penetration path of moisture from the outside, thereby further improving the moisture resistance reliability of the multilayer electronic component 100.

[0068] The ratio of the average size of the second dielectric crystallites to the average size of the first dielectric crystallites is not particularly limited. However, when the ratio of the average size of the second dielectric crystallites to the average size of the first dielectric crystallites is less than 0.10, pores may occur due to sintering mismatch caused by an excessive size difference between the first dielectric crystallites and the second dielectric crystallites, and the moisture resistance reliability may deteriorate, and problems such as cracks may occur. On the other hand, when the ratio of the average size of the second dielectric crystallites to the average size of the first dielectric crystallites exceeds 0.80, the size difference between the first dielectric crystallites and the second dielectric crystallites is not large, so the effect of blocking the penetration of moisture from the outside may be slightly insufficient. Therefore, the ratio of the average size of the second dielectric crystallites to the average size of the first dielectric crystallites can be 0.10 or more and 0.80 or less.

[0069] The method for measuring the ratio of the average size of the second dielectric crystallites to the average size of the first dielectric crystallites is not particularly limited.

[0070] First, the average size of the first dielectric crystal grains may be the average value of the sizes of the dielectric crystal grains measured in the central regions Q1, Q2, and Q3 of the dielectric layer in the cross section (FIG. 3) in the first and second directions of the multilayer electronic component polished to the center in the third direction.

[0071] Meanwhile, each region for measuring the average size of the first dielectric crystal grains may refer to, but is not limited to, an area of ​​5 μm × 5 μm (size in the first direction × size in the second direction) measured in the cross section using a scanning electron microscope (SEM). The average size of the dielectric crystal grains in each region may be determined by, but is not limited to, measuring the lengths of the minor and major axes of 10 or more arbitrary crystal grains in each region and averaging them, or by measuring the area of ​​the crystal grains in pixels and converting them into a circle-equivalent diameter. The average size of the first dielectric crystal grains may be measured in a central region Q1 in the second direction of the dielectric layer located at the top end of the capacitance-forming portion Ac in the first direction, a central region Q2 in the second direction of the dielectric layer located at the center in the first direction, and a central region Q3 in the second direction of the dielectric layer located at the bottom end in the first direction, and then averaging the measurements. This measurement can be further generalized by averaging the average values.

[0072] Next, the average size of the second dielectric crystal grains may be the average value of the sizes of the dielectric crystal grains measured in the central region (FIG. 6, P1, P2, P3) obtained by dividing the region in which the protective portion 150 is formed into three equal parts in the first direction in the cross section (FIG. 3) in the first and second directions of the laminated electronic component polished to the center in the third direction.

[0073] Similarly, each region for measuring the average size of the second dielectric crystal grains may refer to, but is not limited to, an area of ​​first-direction size x second-direction size = 5 μm x 5 μm measured using a scanning electron microscope (SEM) on the cross section. The average size of the dielectric crystal grains in each region may be determined by, but is not limited to, measuring the lengths of the minor and major axes of 10 or more random crystal grains in each region and averaging them, or by measuring the area of ​​the crystal grains in pixels and converting them into a circle-equivalent diameter. The measurement of the average size of the second dielectric crystal grains can be further generalized by measuring the Q1, Q2, and Q3 regions of the protective portion 120 and averaging them.

[0074] In one embodiment, the protective part 120 may cover the third and fourth surfaces 3 and 4 except for the end surfaces Sc of the internal electrodes, thereby improving the connection between the external electrodes 131 and 132 and the internal electrodes 121 and 122.

[0075] Referring to FIG. 2, the end surface Sc of the internal electrode may refer to an area (rectangular area) between the ends of the internal electrode arranged at the uppermost and lowermost ends in the first direction and the end of the internal electrode in the third direction, with one end of the internal electrode connected to the third surface 3 or the fourth surface 4 being the end of the internal electrode.

[0076] The end surface Sc of the internal electrode may refer to a region where the external electrodes 131, 132 are in direct contact with one end of the internal electrodes 121, 122 in the second direction. Therefore, according to one embodiment, when the protective part 120 is applied to cover the region of the third and fourth surfaces 3, 4 excluding the end surface Sc of the internal electrodes, the external electrodes 131, 132 can be formed on all ends of the internal electrodes located on the end surface Sc of the internal electrodes, thereby improving the connectivity between the external electrodes 131, 132 and the internal electrodes 121, 122.

[0077] Referring to FIG. 2, the maximum size of the external electrodes 131 and 132 in the second direction is represented by B, and the maximum size of the protective part 120 in the second direction is represented by A.

[0078] When the protective portion 120 having a finer dielectric crystal grain size than the dielectric layer 111 is formed on the third surface 3 and the fourth surface 4, the phenomenon of short circuits occurring in the laminated electronic component can be mitigated and the moisture resistance reliability can be improved.

[0079] However, if the protective portion 120 is formed to have a size that is excessively longer than the maximum size B in the second direction of the external electrodes 131, 132, the external electrodes 131, 132 may be trapped in the protective portion 120, making it impossible to mount them on a substrate. Therefore, the ratio (A / B) of the maximum size A in the second direction of the protective portion 120 to the maximum size B in the second direction of the external electrodes needs to be appropriately adjusted to improve the mountability of the multilayer electronic component, improve moisture resistance reliability, and prevent short circuits.

[0080] Specifically, the ratio (A / B) of the maximum size A in the second direction of the protective part 120 to the maximum size B in the second direction of the external electrode may be greater than 0.18 and less than 1.00, and more preferably, may be greater than or equal to 0.25 and less than or equal to 0.75.

[0081] If the ratio (A / B) of the maximum size A in the second direction of the protective portion 120 to the maximum size B in the second direction of the external electrode is 0.18 or less, mountability can be ensured, but since the protective portion 120 is not sufficiently formed, it may be difficult to ensure the effect of preventing short circuits and the effect of improving moisture resistance reliability.

[0082] Therefore, when the ratio (A / B) of the maximum size A in the second direction of the protective portion 120 to the maximum size B in the second direction of the external electrode exceeds 0.18, it is possible to simultaneously achieve improved mountability, improved moisture resistance reliability, and the prevention of short circuits.

[0083] However, if the ratio (A / B) of the maximum size A in the second direction of the protective portion 120 to the maximum size B in the second direction of the external electrode is 1.00, excessive formation of the protective portion 120 may make it impossible to mount the multilayer electronic component 100 on a substrate.

[0084] Therefore, in order to ensure mountability, the ratio (A / B) of the maximum size A in the second direction of the protective part 120 to the maximum size B in the second direction of the external electrodes may be less than 1.00.

[0085] The method for measuring the maximum size A of the protective portion 120 in the second direction and the maximum size B of the external electrodes 131 and 132 in the second direction is not particularly limited.

[0086] The maximum size A of the protective portion 120 in the second direction and the maximum size B of the external electrodes 131 and 132 in the second direction may refer to the value of the horizontal distance in the second direction measured from the third or fourth surface 3 or 4 to the outermost point in the second direction of the protective portion 120 and the external electrodes 131 and 132 in a cross section in the first and second directions polished to the center in the third direction of the multilayer electronic component 100 using a scanning electron microscope (SEM) or an optical microscope (OM).

[0087] The maximum size A of the protective portion 120 in the second direction can be adjusted according to the thickness of the ceramic green sheet for forming the protective portion attached to the third or fourth surface 3, 4 of the laminated portion 110, and the maximum size B of the external electrode in the second direction can be adjusted according to the degree of dipping of the external electrode paste before sintering the external electrodes 131, 132.

[0088] Meanwhile, the protective part 120 may be disposed on the side surfaces of the cover parts C1 and C2 in the second direction and the side surfaces of the margin parts M1 and M2 in the second direction according to an embodiment. Specifically, the protective part 120 may be disposed to cover the side surfaces of the cover parts C1 and C2 and the margin parts M1 and M2 in the second direction, which may further enhance the effect of improving moisture resistance reliability according to the present invention.

[0089] The shape of the protective portion 120 is not particularly limited. In Figures 1 to 8, the areas of the third surface 3 and the fourth surface 4 that are not covered by the protective portion 120 are represented as rectangles, but the shape is not limited thereto and may have various shapes. For example, referring to Figures 9 and 10, the areas of the third surface 3 and the fourth surface 4 that are not covered by the protective portion 120' may be oval or circular.

[0090] 11 , the area of ​​the region of the third surface 3 of the laminate 110 that is not covered by the protective portion 120 may be larger than the area of ​​the region of the third surface 3 that is covered by the protective portion 120. This ensures the effect of improving the moisture resistance reliability of the present invention, and also ensures a sufficient area where the first external electrode 131 contacts the first internal electrode 121, thereby improving the electrical connectivity between the first external electrode 131 and the first internal electrode 121. While the relationship with the protective layer 120 has been described with reference to the third surface 3 in FIG. 11 , the same understanding can be obtained using the fourth surface 4 as the reference. Specifically, the area of ​​the region of the fourth surface 4 of the laminate 110 that is not covered by the protective portion 120 may be larger than the area of ​​the region of the fourth surface 4 that is covered by the protective portion.

[0091] The external electrodes 131 and 132 may be disposed on the third surface 3 and the fourth surface 4 of the laminated part 110. Also, referring to FIGS. 3 and 4, the external electrodes 131 and 132 may be disposed on the protective part 120 and cover the protective part 120.

[0092] Referring to FIG. 1, the external electrodes 131 and 132 may include a first external electrode 131 and a second external electrode 132 arranged on the third surface 3 and the fourth surface 4 of the laminated part 110, respectively, and connected to the first internal electrode 121 and the second internal electrode 122, respectively.

[0093] In this embodiment, the multilayer electronic component 100 has a structure having two external electrodes 131 and 132, but the number and shape of the external electrodes 131 and 132 can be changed depending on the shape of the internal electrodes 121 and 122 and other purposes.

[0094] Meanwhile, the external electrodes 130 and 140 may be formed using any material that has electrical conductivity, such as a metal, and the specific material may be determined in consideration of electrical properties, structural stability, etc., and may further have a multi-layer structure.

[0095] For example, the external electrodes 131 and 132 may include an electrode layer disposed in the laminated portion 110 and a plating layer formed on the electrode layer.

[0096] To give a more specific example of the electrode layer, the electrode layer may be a fired electrode containing a conductive metal and glass, or a resin-based electrode containing a conductive metal and resin.

[0097] The electrode layer may be formed by sequentially forming a fired electrode and a resin-based electrode on a laminated portion, or by transferring a sheet containing a conductive metal onto the laminated portion, or by transferring a sheet containing a conductive metal onto a fired electrode.

[0098] The conductive metal contained in the electrode layer may be any material with excellent electrical conductivity, and is not particularly limited. For example, the conductive metal may be one or more of nickel (Ni), copper (Cu), and alloys thereof.

[0099] The plating layer serves to improve mounting characteristics. The type of plating layer is not particularly limited, and may be a plating layer containing one or more of Ni, Sn, Pd, and alloys thereof, or may be formed of multiple layers.

[0100] More specifically, the plating layer may be a Ni plating layer or a Sn plating layer, or may be a form in which a Ni plating layer and a Sn plating layer are sequentially formed on an electrode layer, or a form in which a Sn plating layer, a Ni plating layer, and a Sn plating layer are sequentially formed. Also, the plating layer may include a plurality of Ni plating layers and / or a plurality of Sn plating layers.

[0101] The size of the multilayer electronic component 100 does not need to be particularly limited.

[0102] For example, in order to simultaneously achieve miniaturization and high capacity, the laminated electronic component 100 may have a size of 0201 (length x width, 0.2 mm x 0.1 mm) or less, or in the case of a product in which reliability in a high-temperature, high-pressure environment is important, may have a size of 3216 (length x width, 3.2 mm x 1.6 mm) or more, but is not limited to these.

[0103] Here, the length of the multilayer electronic component 100 may refer to the maximum size of the multilayer electronic component 100 in the second direction, the thickness of the multilayer electronic component 100 may refer to the maximum size of the multilayer electronic component 100 in the first direction, and the width of the multilayer electronic component 100 may refer to the maximum size of the multilayer electronic component 100 in the third direction.

[0104] (Example) Table 1 below shows the results of evaluating the mountability, short circuit occurrence rate, and moisture resistance reliability depending on the ratio (A / B) of the maximum size A in the second direction of the protective part 120 to the maximum size B in the second direction of the external electrode.

[0105] The multilayer electronic component samples for which the characteristics were evaluated in the test process shown in Table 1 were prepared by printing internal electrodes on a dielectric molding sheet to form a laminated bar, cutting the laminated bar, and then pressurizing and adhering a ceramic green sheet for forming a protective portion to the side of the cut laminated bar. The laminated bar and the ceramic green sheet were then subjected to plasticization, plasticization in a reducing atmosphere, and re-oxidation processes.

[0106] At this time, the thickness of the ceramic green sheet for forming the protective portion and the degree of dipping of the external electrode paste were varied for each test number to adjust the A / B value, but the other conditions were the same.

[0107] The maximum size A of the protective portion 120 in the second direction and the maximum size B of the external electrodes 131, 132 in the second direction were measured using an optical microscope (OM) on cross sections in the first and second directions polished to the center of the laminated electronic component 100 in the third direction, and the horizontal distance in the second direction from the third or fourth surface 3, 4 to the outermost points in the second direction of the protective portion 120 and the external electrodes 131, 132.

[0108] To evaluate the mountability, soldering was performed on one board, 400 multilayer electronic components were mounted, and then reflow was performed. When the board was then turned over, if 200 or more multilayer electronic components fell off, it was judged as NG (X), and if fewer than 200 fell off, it was judged as OK (○).

[0109] The short-circuit rate was evaluated by measuring the capacitance of 30 multilayer electronic components with a capacitance meter, and determining that the multilayer electronic components had a DF (Dissipation Factor) of 0.1 or more as short-circuited. The proportion of short-circuited multilayer electronic components out of the 30 was expressed as a percentage.

[0110] The moisture resistance reliability was evaluated for 1,200 samples per test number at 1.2Vr, 85°C, and a relative humidity of 85%, and samples whose insulation resistance value had dropped by 100 times or more from the initial insulation resistance value were judged to be defective.

[0111] [Table 1]

[0112] Test No. 1 is a case where no protective portion is formed, and it can be confirmed that the short circuit rate is 100%.

[0113] Test No. 2 is the case where A / B is 0.05, and it can be confirmed that the short circuit rate is 20%.

[0114] Test numbers 3 and 4 are cases where A / B is 0.18 or less or less than 0.25, and it can be seen that although the short circuit rate decreases as A / B increases, sufficient moisture resistance reliability cannot be ensured.

[0115] Test numbers 5 to 9 are the cases where A / B is greater than 0.18 and less than 1.00, or 0.25 or greater and 0.75 or less, and the short-circuit rate is 0%, confirming excellent mountability and moisture resistance reliability.

[0116] Test No. 10 corresponds to a case where A / B of the external electrodes is 1, which is impossible to mount. Therefore, A / B is preferably less than 1, and more preferably 0.75 or less.

[0117] Therefore, when the ratio (A / B) of the maximum size A in the second direction of the protective portion 120 to the maximum size B in the second direction of the external electrode is greater than 0.18 and less than 1.00, more preferably greater than or equal to 0.25 and less than or equal to 0.75, excellent mountability and moisture resistance reliability can be ensured and the occurrence of short circuits can be suppressed.

[0118] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and the accompanying drawings, but is limited by the scope of the appended claims. Therefore, various substitutions, modifications, and changes may be made by a person skilled in the art within the scope of the claims without departing from the technical idea of ​​the present invention, and these also fall within the scope of the present invention.

[0119] Furthermore, the expression "one embodiment" used in this disclosure does not mean the same embodiment, but is provided to emphasize and describe each unique feature that is different from the others. However, the above-described one embodiment does not exclude being realized in combination with features of another embodiment. For example, even if a feature described in one embodiment is not described in another embodiment, it can be understood as being related to the other embodiment unless there is a description in the other embodiment that contradicts or contradicts the feature.

[0120] The terms used in this disclosure are merely used to describe one embodiment and are not intended to limit the disclosure. In this case, singular expressions include plural expressions unless the context clearly indicates a different meaning. [Explanation of symbols]

[0121] 100: Multilayer electronic components 110: Laminated section 120:Protection Department 111: Dielectric layer 121, 122: Internal electrode 131, 132: External electrode C1, C2: Cover M1, M2: Margins Ac: Capacitance forming part

Claims

1. a laminated portion including: dielectric layers; internal electrodes alternately disposed with the dielectric layers in a first direction; first and second surfaces facing the first direction; third and fourth surfaces facing a second direction perpendicular to the first direction and connected to at least a portion of the internal electrodes; and fifth and sixth surfaces facing a third direction perpendicular to the first and second directions; a protective portion disposed on the third surface and the fourth surface; an external electrode disposed on the laminated portion and the protective portion and connected to the internal electrode, the dielectric layer includes first dielectric crystal grains, and the protective portion includes second dielectric crystal grains; The average size of the second dielectric crystal grains is smaller than the average size of the first dielectric crystal grains.

2. When one end of the internal electrode in the second direction connected to the third surface or the fourth surface is defined as an end of the internal electrode, and a region between both line segments connecting the ends of the internal electrodes arranged at the uppermost and lowermost ends in the first direction and the ends of the internal electrodes in the third direction is defined as an end face of the internal electrode, 2. The multilayer electronic component according to claim 1, wherein the protective portion covers areas of the third surface and the fourth surface excluding end surfaces of the internal electrodes.

3. The multilayer electronic component according to claim 2 , wherein the areas of the third surface and the fourth surface that are not covered by the protective portion are rectangular.

4. The multilayer electronic component according to claim 2 , wherein the areas of the third surface and the fourth surface that are not covered by the protective portion are elliptical or circular.

5. 2. The multilayer electronic component according to claim 1, wherein a ratio of an average size of said second dielectric crystal grains to an average size of said first dielectric crystal grains is 0.10 or more and 0.8 or less.

6. The multilayer electronic component according to claim 1 , wherein a ratio of the maximum size of the protective portion in the second direction to the maximum size of the external electrodes in the second direction is greater than 0.18 and less than 1.

00.

7. 2 . The multilayer electronic component according to claim 1 , wherein a ratio of the maximum size of the protective portion in the second direction to the maximum size of the external electrodes in the second direction is equal to or greater than 0.25 and equal to or less than 0.

75.

8. 2. The multilayer electronic component according to claim 1, wherein both ends of the internal electrodes in the third direction are disposed spaced apart from the fifth surface and the sixth surface.

9. 2. The multilayer electronic component according to claim 1, wherein the internal electrodes have a rectangular shape in cross sections of the multilayer portion taken along the second and third directions.

10. The multilayer electronic component according to claim 1 , wherein the internal electrodes have substantially the same size in the third direction along the second direction.

11. the laminated section includes a capacitance forming section in which the internal electrodes and the dielectric layers are alternately arranged to form a capacitance, and cover sections that are arranged on both sides of the capacitance forming section in a first direction, The multilayer electronic component according to claim 1 , wherein an average size of the cover in the first direction is 0.25 times or less the maximum size of the multilayer electronic component in the first direction.

12. the laminated section includes a capacitance forming section in which the internal electrodes and the dielectric layers are alternately arranged to form a capacitance, and margin sections that are arranged on both sides of the capacitance forming section in a third direction, 11. The multilayer electronic component according to claim 1, wherein an average size of the margin portion in the third direction is 0.25 times or less the maximum size of the multilayer electronic component in the third direction.

13. 11. The multilayer electronic component according to claim 1, wherein an area of ​​a region of the third surface and the fourth surface that is not covered by the protective portion is larger than an area of ​​a region of the third surface and the fourth surface that is covered by the protective portion.

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