CN-122000202-A - Multilayer ceramic capacitor

Abstract

The present disclosure provides a multilayer ceramic capacitor including a capacitor body including a dielectric layer and an inner electrode layer, and an outer electrode disposed on an outer surface of the capacitor body. The dielectric layer includes a plurality of dielectric grains, at least one dielectric grain of the plurality of dielectric grains having a core-shell structure including a core portion and a shell portion surrounding at least a portion of the core portion. The dielectric crystal grain having the core-shell structure includes barium (Ba), titanium (Ti), and a rare earth element including lanthanum (La). In a measurement region extending from an interface between the core portion and the shell portion to a depth of about 5nm into the shell portion, an absolute value of a concentration gradient of lanthanum (La) is about 0.12 molar parts to 0.58 molar parts per nanometer based on 100 molar parts of titanium (Ti).

Inventors

• LI JIXI
• Wu Zhixie
• LI ZHIXIAN
• Quan Jiongjun
• JIN ZHENGLIE

Assignees

• 三星电机株式会社

Dates

Publication Date

20260508

Application Date

20250912

Priority Date

20241105

Claims (17)

1. 1. A multilayer ceramic capacitor comprising: a capacitor body including a dielectric layer and an internal electrode layer, and An external electrode disposed on an outer surface of the capacitor body, Wherein the dielectric layer comprises a plurality of dielectric grains, At least one dielectric die of the plurality of dielectric dies has a core-shell structure including a core portion and a shell portion surrounding at least a portion of the core portion, Wherein the dielectric crystal grain having the core-shell structure includes Ba, ti, and a rare earth element including La, and In a measurement region having a depth of 5nm from an interface between the core portion and the shell portion to the shell portion from the interface, an absolute value of a concentration gradient of La is 0.12 mol parts/nm to 0.58 mol parts/nm based on 100 mol parts of Ti.
2. 2. The multilayer ceramic capacitor according to claim 1, wherein, In transmission electron microscopy-energy dispersive spectral line analysis of long axis straight line segments passing through the center of the dielectric grains having the core-shell structure, The core is a region having La of less than 0.8 molar parts based on 100 molar parts of Ti, and The shell portion is a region of 0.8 molar parts or more of La based on 100 molar parts of Ti.
3. 3. The multilayer ceramic capacitor according to claim 1, wherein, The molar content of La in the shell portion is higher than that in the core portion.
4. 4. The multilayer ceramic capacitor according to claim 1, wherein, In the shell portion, the content of La is 0.8 molar part or more and 2.0 molar parts or less based on 100 molar parts of Ti.
5. 5. The multilayer ceramic capacitor according to claim 1, wherein, The rare earth element further includes at least one auxiliary element selected from the group consisting of Sc, Y, nd, eu, gd, tb, dy, ho, er, yb and Lu.
6. 6. The multilayer ceramic capacitor according to claim 1, wherein, The rare earth element further includes an auxiliary element including Y, tb and Dy.
7. 7. The multilayer ceramic capacitor according to claim 1, wherein, The capacitor body includes an active region in which the dielectric layers and the internal electrode layers are alternately arranged in a stacking direction, and In a central region of the effective region, an average size of the dielectric crystal grains having the core-shell structure is 10nm or more and 130nm or less, the central region being a region in which a horizontal length from a center of the effective region in a direction perpendicular to the stacking direction to both vertical edges of the central region corresponds to 1/6 of a total horizontal length of the effective region, and a vertical length from the center of the effective region in the stacking direction to both horizontal edges of the central region corresponds to 1/6 of the total vertical length of the effective region.
8. 8. The multilayer ceramic capacitor according to claim 7, wherein, In the central region, the average size of the core portion is 35% to 67.3% of the average size of the dielectric crystal grains having the core-shell structure.
9. 9. A multilayer ceramic capacitor comprising: a capacitor body including a dielectric layer and an internal electrode layer, and An external electrode disposed on an outer surface of the capacitor body, Wherein the dielectric layer comprises a plurality of dielectric grains, At least one dielectric die of the plurality of dielectric dies has a core-shell structure including a core portion and a shell portion surrounding at least a portion of the core portion, Wherein the dielectric crystal grain having the core-shell structure includes Ba, ti and a rare earth element, and the rare earth element includes La, and at least one auxiliary element selected from the group consisting of Sc, Y, nd, eu, gd, tb, dy, ho, er, yb and Lu, and In a measurement region having a depth of 5nm from an interface between the core portion and the shell portion to the shell portion from the interface, an absolute value of a total concentration gradient of the rare earth element is 0.12 mol parts/nm to 0.58 mol parts/nm based on 100 mol parts of Ti.
10. 10. The multilayer ceramic capacitor according to claim 9, wherein, In transmission electron microscopy-energy dispersive spectral line analysis of long axis straight line segments passing through the center of the dielectric grains having the core-shell structure, The core is a region having La of less than 0.8 molar parts based on 100 molar parts of Ti, and The shell portion is a region of 0.8 molar parts or more of La based on 100 molar parts of Ti.
11. 11. The multilayer ceramic capacitor according to claim 9, wherein, The total molar content of the rare earth elements in the shell portion is higher than the total molar content of the rare earth elements in the core portion.
12. 12. The multilayer ceramic capacitor according to claim 9, wherein, In the shell portion, the total content of the rare earth elements is 1.2 mol parts or more and 5.5 mol parts or less based on 100 mol parts of Ti.
13. 13. The multilayer ceramic capacitor according to claim 9, wherein, The capacitor body includes an active region in which the dielectric layers and the internal electrode layers are alternately arranged in a stacking direction, and In a central region of the effective region, an average size of the dielectric crystal grains having the core-shell structure is 10nm or more and 130nm or less, the central region being a region in which a horizontal length from a center of the effective region in a direction perpendicular to the stacking direction to both vertical edges of the central region corresponds to 1/6 of a total horizontal length of the effective region, and a vertical length from the center of the effective region in the stacking direction to both horizontal edges of the central region corresponds to 1/6 of the total vertical length of the effective region.
14. 14. The multilayer ceramic capacitor according to claim 13, wherein, In the central region, the average size of the core portion is 35% to 67.3% of the average size of the dielectric crystal grains having the core-shell structure.
15. 15. The multilayer ceramic capacitor according to claim 9, wherein, The rare earth elements include La, Y, tb and Dy.
16. 16. The multilayer ceramic capacitor according to claim 15, wherein, The total molar content of La, Y, tb, and Dy in the shell portion is higher than the total molar content of La, Y, tb, and Dy in the core portion.
17. 17. The multilayer ceramic capacitor according to claim 15, wherein, In the shell portion, the total content of La, Y, tb, and Dy is 1.2 mol parts or more and 5.5 mol parts or less based on 100 mol parts of Ti.

Description

Multilayer ceramic capacitor Technical Field The present disclosure relates to a multilayer ceramic capacitor. Background As ceramic electronic components using ceramic materials, there are capacitors, inductors, piezoelectric elements, piezoresistors, thermistors, and the like. Among ceramic electronic components, a multilayer ceramic capacitor (MLCC) is used in various electronic devices due to advantages such as small size, high capacitance, easy installation, and the like. For example, a multilayer ceramic capacitor (MLCC) may be a chip capacitor mounted on a printed circuit board of various electronic products such as an imaging device (e.g., a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP), etc.), a computer, a personal portable terminal (e.g., a smart phone), etc., for charging or discharging thereof. Recently, a technique of reducing the thickness of the dielectric layer and the thickness of the internal electrode layer to achieve ultra-high capacitance in an ultra-small multilayer ceramic capacitor has been proposed. In addition, design studies are being conducted to achieve a uniform resistance distribution by controlling the grain size and distribution within the dielectric layer. Disclosure of Invention Embodiments provide a multilayer ceramic capacitor having excellent DC bias characteristics. Embodiments provide a multilayer ceramic capacitor including a capacitor body including a dielectric layer and an inner electrode layer, and an outer electrode disposed on an outer surface of the capacitor body, wherein the dielectric layer includes a plurality of dielectric grains, 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 portion of the core portion, the dielectric grains having the core-shell structure include barium (Ba), titanium (Ti), and a rare earth element including lanthanum (La), and an absolute value of a concentration gradient of lanthanum (La) is about 0.12 molar parts/nm to about 0.58 molar parts/nm based on 100 molar parts of titanium (Ti) in a measurement region from an interface between the core portion and the shell portion to a depth of about 5nm from the interface toward the shell portion when measured from the interface toward the shell portion. In TEM-EDS (transmission electron microscope-energy dispersive spectroscopy) line analysis of a long axis straight line segment passing through the center of the dielectric crystal grain having the core-shell structure, the core portion may be a region of lanthanum (La) less than 0.8 molar part based on 100 molar parts of titanium (Ti), and the shell portion may be a region of lanthanum (La) equal to or greater than 0.8 molar part based on 100 molar parts of titanium (Ti). The molar content of lanthanum (La) in the shell portion may be higher than that in the core portion. In the shell portion, the lanthanum (La) content may be 0.8 molar parts or more and about 2.0 molar parts or less based on 100 molar parts of titanium (Ti). The rare earth element may further include at least one auxiliary element 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). The rare earth element may further include an auxiliary element including yttrium (Y), terbium (Tb), and dysprosium (Dy). The capacitor body may include an active region in which the dielectric layers and the internal electrode layers are alternately disposed in a stacking direction, and an average size of the dielectric grains having the core-shell structure may be about 10nm or more and less than about 130nm in a central region of the active region, the central region being a region in which a horizontal length from a center of the active region in a direction perpendicular to the stacking direction to both vertical edges of the central region corresponds to about 1/6 of a total horizontal length of the active region, and a vertical length from the center of the active region in the stacking direction to both horizontal edges of the central region corresponds to about 1/6 of the total vertical length of the active region. In the central region, the average size of the core portion may be about 35% to about 67.3% of the average size of the dielectric grains having the core-shell structure. Another embodiment provides a multilayer ceramic capacitor comprising a capacitor body comprising a dielectric layer and an inner electrode layer, and an outer electrode disposed on an outer surface of the capacitor body, wherein the dielectric layer comprises a plurality of dielectric grains, at least one of the plurality of dielectric grains has a core-shell structure comprising a core portion and a shell portion surrounding at least a portion of the core portion, the dielectric grains having a core-shell structure comprising barium (Ba), titanium (Ti) and a rare ea