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KR-20260067271-A - MULTILAYER CERAMIC CAPACITOR

KR20260067271AKR 20260067271 AKR20260067271 AKR 20260067271AKR-20260067271-A

Abstract

A multilayer ceramic capacitor is provided, comprising a capacitor body including a dielectric layer and an internal electrode layer, and an external electrode disposed on the outside of the capacitor body, wherein the dielectric layer comprises a plurality of dielectric grains, and at least one of the plurality of dielectric grains has a core-shell structure including a core portion and a shell portion surrounding at least a part of the core portion, and the dielectric grain having the core-shell structure comprises rare earth elements including barium (Ba), titanium (Ti), and lanthanum (La), and when measured in the direction from the interface to the shell portion in a measurement region from the interface to a depth of 5 nm from the interface to the shell portion, the absolute value of the concentration gradient of lanthanum (La) is 0.12 molar parts/nm to 0.58 molar parts/nm based on 100 molar parts of titanium (Ti).

Inventors

  • 이제희
  • 오지섭
  • 이지현
  • 전형준
  • 김정렬

Assignees

  • 삼성전기주식회사

Dates

Publication Date
20260512
Application Date
20241231
Priority Date
20241105

Claims (17)

  1. A capacitor body including a dielectric layer and an internal electrode layer, and It includes an external electrode disposed on the outer side of the capacitor body, and The above dielectric layer comprises a plurality of dielectric grains, and At least one of the plurality of dielectric crystal grains has a core-shell structure comprising a core portion and a shell portion surrounding at least a part of the core portion, and The dielectric crystal grains having the above core-shell structure include rare earth elements including barium (Ba), titanium (Ti), and lanthanum (La), and A multilayer ceramic capacitor in which, when measured from the interface between the core part and the shell part to a depth of 5 nm from the interface towards the shell part, the absolute value of the concentration gradient of the lanthanum (La) is 0.12 molar parts/nm to 0.58 molar parts/nm based on 100 molar parts of titanium (Ti).
  2. In paragraph 1, When performing TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) line analysis on a straight section of the major axis passing through the center of a dielectric grain having the above-mentioned core-shell structure, The above core portion is a region where the lanthanum (La) is less than 0.8 moles with respect to 100 moles of titanium (Ti), and A multilayer ceramic capacitor in which the shell portion is a region in which the lanthanum (La) is 0.8 moles or more with respect to 100 moles of titanium (Ti).
  3. In Paragraph 1, The above lanthanum (La) is a multilayer ceramic capacitor having a higher molar content in the shell portion than in the core portion.
  4. In paragraph 1, A multilayer ceramic capacitor in which the content of lanthanum (La) in the shell portion is 0.8 moles or more to 2.0 moles or less per 100 moles of titanium (Ti).
  5. In paragraph 1, A multilayer ceramic capacitor comprising one or more auxiliary elements selected from scandium (Sc), yttrium (Y), neodymium (Nd), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), ytterbium (Yb), and lutetium (Lu), wherein the above rare earth element further comprises scandium (Sc), yttrium (Y), neodymium (Nd), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), ytterbium (Yb), and lutetium (Lu).
  6. In paragraph 1, A multilayer ceramic capacitor comprising additional auxiliary elements including yttrium (Y), terbium (Tb), and dysprosium (Dy) among the above rare earth elements.
  7. In paragraph 1, The capacitor body includes an active region in which the dielectric layer and the internal electrode layer are alternately arranged. A multilayer ceramic capacitor having a core-shell structure, wherein the average size of the dielectric crystal grains is 10 nm or more and less than 130 nm in a central region having a horizontal length corresponding to 1/6 of the total horizontal length of the active region facing in the vertical direction of the stacking direction from the center of the active region, and a vertical length corresponding to 1/6 of the total vertical length of the active region facing in the stacking direction.
  8. In Paragraph 7, A multilayer ceramic capacitor in which, in the central region above, the average size of the core portion is 35% to 67.3% of the average size of the dielectric crystal grains.
  9. A capacitor body including a dielectric layer and an internal electrode layer, and It includes an external electrode disposed on the outer side of the capacitor body, and The above dielectric layer comprises a plurality of dielectric grains, and At least one of the plurality of dielectric crystal grains has a core-shell structure comprising a core portion and a shell portion surrounding at least a part of the core portion, and The dielectric crystal grain having the above core-shell structure comprises barium (Ba), titanium (Ti), and rare earth elements, and the rare earth element comprises lanthanum (La); and one or more auxiliary elements selected from scandium (Sc), yttrium (Y), neodymium (Nd), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), ytterbium (Yb), and lutetium (Lu). A multilayer ceramic capacitor in which, when measured from the interface between the core part and the shell part to a depth of 5 nm from the interface towards the shell part, the absolute value of the total concentration gradient of the rare earth element is 0.12 molar parts/nm to 0.58 molar parts/nm based on 100 molar parts of titanium (Ti).
  10. In Paragraph 9, When performing TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) line analysis on a straight section of the major axis passing through the center of a dielectric grain having the above-mentioned core-shell structure, The above core portion is a region where the lanthanum (La) is less than 0.8 moles with respect to 100 moles of titanium (Ti), and A multilayer ceramic capacitor in which the shell portion is a region in which the lanthanum (La) is 0.8 moles or more with respect to 100 moles of titanium (Ti).
  11. In Paragraph 9, A multilayer ceramic capacitor having a higher molar content of the total rare earth element in the shell portion than in the core portion.
  12. In Paragraph 9, A multilayer ceramic capacitor in which the total content of the rare earth element in the shell portion is 1.2 moles or more to 5.5 moles or less per 100 moles of titanium (Ti).
  13. In Paragraph 9, The capacitor body includes an active region in which the dielectric layer and the internal electrode layer are alternately arranged. A multilayer ceramic capacitor having a core-shell structure, wherein the average size of the dielectric crystal grains is 10 nm or more and less than 130 nm in a central region having a horizontal length corresponding to 1/6 of the total horizontal length of the active region facing in the vertical direction of the stacking direction from the center of the active region, and a vertical length corresponding to 1/6 of the total vertical length of the active region facing in the stacking direction.
  14. In Paragraph 13, A multilayer ceramic capacitor in which, in the central region above, the average size of the core portion is 35% to 67.3% of the average size of the dielectric crystal grains.
  15. In Paragraph 9, The above rare earth elements are a multilayer ceramic capacitor comprising La, Y, Tb, and Dy.
  16. In Paragraph 15, A multilayer ceramic capacitor having a higher molar content in the shell portion than in the core portion for the total content of La, Y, Tb, and Dy.
  17. In Paragraph 15, A multilayer ceramic capacitor in which the total content of La, Y, Tb, and Dy in the shell portion is 1.2 moles or more to 5.5 moles or less per 100 moles of titanium (Ti).

Description

Multilayer Ceramic Capacitor The present disclosure relates to a multilayer ceramic capacitor. Electronic components that use ceramic materials include capacitors, inductors, piezoelectric elements, varistors, and thermistors. Among these ceramic electronic components, multilayer ceramic capacitors (MLCCs) can be used in various electronic devices due to their advantages of being small, ensuring high capacitance, and being easy to mount. For example, multilayer ceramic capacitors (MLCCs) can be used as chip-type capacitors mounted on the substrates of various electronic products, such as video devices (liquid crystal displays, LCDs), plasma display panels (PDPs), and organic light-emitting diodes (OLEDs), computers, personal portable terminals, and smartphones, to charge or discharge electricity. Recently, techniques to thin the dielectric and internal electrode layers have been proposed to achieve ultra-high capacitance in ultra-small multilayer ceramic capacitors. In addition, design research is underway to achieve a uniform resistance distribution by controlling the grain size and dispersion within the dielectric layer. FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to one embodiment. Figure 2 is a cross-sectional view of a multilayer ceramic capacitor cut along line II' of Figure 1. Figure 3 is a cross-sectional view of a multilayer ceramic capacitor cut along the line II-II' of Figure 1. Figure 4 is an exploded perspective view showing the stacked structure of the capacitor body of Figure 1 after disassembly. FIG. 5 is a schematic diagram showing a dielectric layer according to one embodiment. FIG. 6 is a schematic diagram showing a dielectric crystal grain according to one embodiment. Figure 7 is an enlarged view of area A in Figure 2. Figure 8 is a TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) mapping analysis image of the dielectric layer according to Example 1. Figure 9 is an image showing the content of lanthanum (La) during TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) line analysis of the dielectric layer according to Example 1. Figure 10 is an image showing the total content of rare earth elements during TEM-EDS (Transmission Electron Microscopy-Energy Dispersive Spectroscopy) line analysis of the dielectric layer according to Example 1. Figure 11 is a graph showing the average size of dielectric grains according to Example 1 and Comparative Example 2. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. In order to clearly explain the invention in the drawings, parts unrelated to the explanation have been omitted, and the same reference numerals have been used for identical or similar components throughout the specification. Furthermore, in the attached drawings, some components may be exaggerated, omitted, or schematically depicted, and the size of each component does not entirely reflect its actual size. The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included. Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. Furthermore, when it is said that a part, such as a layer, membrane, region, or plate, is "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when it is said that a part is "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" in the direction opposite to gravity. Throughout the specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Accordingly, when a part is said to “comprising” a certain component, unless specifically stated otherwise, this means that it may include additional components rather than excluding other components. Additionally, throughout the specification, "planar" means when the subject part is vie