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US-20260128229-A1 - MULTILAYER CERAMIC CAPACITOR

US20260128229A1US 20260128229 A1US20260128229 A1US 20260128229A1US-20260128229-A1

Abstract

In a multilayer ceramic capacitor, a laminate includes an inner layer portion including first and second internal electrode layers, and an outer layer portion including a dielectric material. When a length in a direction parallel to a lamination direction of the inner layer portion at a central position thereof in a width direction is defined as a first length, and when a length in the parallel direction parallel, at a position at which a length from a width-direction end portion of the inner layer portion in the direction parallel to the another width-direction end portion of the inner layer portion in the width direction is about 0.3-8.0% of the length of the inner layer portion in the width direction, is defined as a second length, the second length is longer than the first length.

Inventors

  • Masahiro Kasahara
  • Yasuyuki Shimada
  • Shun IWATA

Assignees

  • MURATA MANUFACTURING CO., LTD.

Dates

Publication Date
20260507
Application Date
20260105
Priority Date
20230719

Claims (19)

  1. 1 . A multilayer ceramic capacitor comprising: a multilayer body including a dielectric layer, a first internal electrode layer and a second internal electrode layer, a first main surface and a second main surface opposed to each other in a lamination direction, a first end surface and a second end surface opposed to each other in a length direction perpendicular or substantially perpendicular to the lamination direction, and a first lateral surface and a second lateral surface opposed to each other in a width direction perpendicular or substantially perpendicular to the lamination direction and the length direction; a first external electrode on the first end surface; and a second external electrode on the second end surface; wherein the multilayer body includes: an inner layer portion where the first internal electrode layer and the second internal electrode layer are opposed to each other; and outer layer portions each including a dielectric material; when defining a length in a direction parallel or substantially parallel to the lamination direction of the inner layer portion at a middle position in the width direction of the inner layer portion as a first length, and defining a length in a direction parallel or substantially parallel to the lamination direction of the inner layer portion at a position where a length from an end portion in the width direction of the inner layer portion in a direction parallel to one other end portion in the width direction of the inner layer portion is about 0.3% or more and about 8.0% or less of a length in the width direction of the inner layer portion as a second length; the second length is longer than the first length.
  2. 2 . The multilayer ceramic capacitor according to claim 1 , wherein the second length is about 102.6% or less of the first length.
  3. 3 . The multilayer ceramic capacitor according to claim 1 , wherein a difference between the second length and the first length is about 30 μm or less.
  4. 4 . The multilayer ceramic capacitor according to claim 1 , wherein, when defining a length in a direction parallel or substantially parallel to the lamination direction of the inner layer portion at the end portion in the width direction of the inner layer portion as a third length, the third length is shorter than the first length.
  5. 5 . The multilayer ceramic capacitor according to claim 1 , wherein, when defining a length in a direction parallel or substantially parallel to the width direction of the inner layer portion at a middle position in the lamination direction of the inner layer portion as a fourth length, and defining a length in a direction parallel or substantially parallel to the width direction of the inner layer portion at a position where a length from an end portion in the lamination direction of the inner layer portion toward the middle position in the lamination direction of the inner layer portion is about 10% or more and about 40% or less of a length in the lamination direction of the inner layer portion as a fifth length, the fifth length is shorter than the fourth length.
  6. 6 . The multilayer ceramic capacitor according to claim 5 , wherein, when defining a length in a direction parallel or substantially parallel to the width direction of the inner layer portion at the end portion in the lamination direction of the inner layer portion as a sixth length, the sixth length is shorter than the fifth length.
  7. 7 . A multilayer ceramic capacitor comprising: a multilayer body including a dielectric layer, a first internal electrode layer and a second internal electrode layer, a first main surface and a second main surface opposed to each other in a lamination direction, a first end surface and a second end surface opposed to each other in a length direction perpendicular or substantially perpendicular to the lamination direction, and a first lateral surface and a second lateral surface opposed to each other in a width direction perpendicular or substantially perpendicular to the lamination direction and the length direction; a first external electrode on the first end surface; and a second external electrode on the second end surface; wherein the multilayer body includes an inner layer portion where the first internal electrode layer and the second internal electrode layer are opposed to each other; and W 3 <W 1 <W 2 is satisfied, where W 1 denotes a length of the inner layer portion on width direction middle position in the lamination direction, W 2 denotes a length of the inner layer portion on width direction end portion vicinity position in the lamination direction, and W 3 denotes a length of the inner layer portion on denotes width direction end portion in the lamination direction.
  8. 8 . The multilayer ceramic capacitor according to claim 7 , wherein D 6 <D 4 is satisfied, where D 4 denotes a length of the inner layer portion on a lamination direction middle position in the width direction and D 6 denotes a length of the inner layer portion on a lamination direction end portion in the width direction.
  9. 9 . The multilayer ceramic capacitor according to claim 7 , wherein a lamination direction dimension of the dielectric layer is longer at the width direction end portion vicinity position than at the width direction middle position.
  10. 10 . The multilayer ceramic capacitor according to claim 7 , wherein a lamination direction dimension of the dielectric layer is longer at the width direction end portion than at the width direction end portion vicinity position.
  11. 11 . The multilayer ceramic capacitor according to claim 9 , wherein the lamination direction dimension of the dielectric layer is longer at the width direction end portion than at the width direction end portion vicinity position.
  12. 12 . The multilayer ceramic capacitor according to claim 7 , wherein a lamination direction dimension of the first internal electrode layer is shorter at the width direction end portion than at the width direction end portion vicinity position.
  13. 13 . The multilayer ceramic capacitor according to claim 7 , wherein a lamination direction dimension of the first internal electrode layer is shorter at the width direction end portion vicinity position than at the width direction middle position.
  14. 14 . The multilayer ceramic capacitor according to claim 12 , wherein the lamination direction dimension of the first internal electrode layer is shorter at the width direction end portion vicinity position than at the width direction middle position.
  15. 15 . The multilayer ceramic capacitor according to claim 7 , wherein D 6 <D 5 is satisfied, where D 5 denotes a length of the inner layer portion on a lamination direction end portion vicinity position in the width direction and D 6 denotes a length of the inner layer portion on a lamination direction end portion in the width direction.
  16. 16 . The multilayer ceramic capacitor according to claim 7 , wherein D 5 <D 4 is satisfied, where D 4 denotes a length of the inner layer portion on a lamination direction middle position in the width direction and D 5 denotes a length of the inner layer portion on a lamination direction end portion vicinity position in the width direction.
  17. 17 . The multilayer ceramic capacitor according to claim 8 , wherein D 6 <D 5 is satisfied, where D 5 denotes a length of the inner layer portion on a lamination direction end portion vicinity position in the width direction and D 6 denotes a length of the inner layer portion on a lamination direction end portion in the width direction.
  18. 18 . The multilayer ceramic capacitor according to claim 8 , wherein D 5 <D 4 is satisfied, where D 4 denotes a length of the inner layer portion on a lamination direction middle position in the width direction and D 5 denotes a length of the inner layer portion on a lamination direction end portion vicinity position in the width direction.
  19. 19 . A multilayer ceramic capacitor comprising: a multilayer body including a dielectric layer, a first internal electrode layer and a second internal electrode layer, a first main surface and a second main surface opposed to each other in a lamination direction, a first end surface and a second end surface opposed to each other in a length direction perpendicular or substantially perpendicular to the lamination direction, and a first lateral surface and a second lateral surface opposed to each other in a width direction perpendicular or substantially perpendicular to the lamination direction and the length direction; a first external electrode on the first end surface; and a second external electrode on the second end surface; wherein the multilayer body includes an inner layer portion where the first internal electrode layer and the second internal electrode layer are opposed to each other; and D 6 <D 5 <D 4 is satisfied, where D 4 denotes a length of the inner layer portion on a lamination direction middle position in the width direction, D 5 denotes a length of the inner layer portion on a lamination direction end portion vicinity position in the width direction, and D 6 denotes a length of the inner layer portion on a lamination direction end portion in the width direction.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2023-117661 filed on Jul. 19, 2023 and is a Continuation Application of PCT Application No. PCT/JP2024/017065 filed on May 8, 2024. The entire contents of each application are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multilayer ceramic capacitors. 2. Description of the Related Art When manufacturing a multilayer ceramic capacitor, a plurality of dielectric sheets are prepared and these dielectric sheets are stacked. In recent years, multilayer ceramic capacitors have been developed with thinner and more abundant layers of dielectric sheets in order to achieve a reduction in size and higher capacitance. Furthermore, in order to improve the durability of multilayered multilayer ceramic capacitors, Japanese Unexamined Patent Application Publication No. 2001-267173 discloses a technique to include a glass component in external electrodes. However, with the progression of thinning and increasing layers of the dielectric sheets, the durability may decrease, particularly at the end portions of the internal electrode layers. Examples of decreased durability include the following. When manufacturing a multilayer ceramic capacitor, the stacked dielectric sheets are pressed. This pressing may cause the dielectric layers to become thinner at the end portions of the internal electrode layers. On the other hand, at the end portions of the internal electrode layers, the electric field strength becomes greater compared to other portions of the internal electrode layers due to the edge effect. Therefore, electric field concentration occurs at the end portions of the internal electrode layers where the dielectric layers are thin, resulting in dielectric breakdown. This decrease in durability becomes more problematic when attempting to achieve higher capacitance. This is because the thickness of the dielectric layers is made even thinner in order to increase capacitance. SUMMARY OF THE INVENTION Example embodiments of the present invention provide multilayer ceramic capacitors each achieving high reliability and high capacitance. An example embodiment of the present invention provides a multilayer ceramic capacitor which includes a multilayer body including a plurality of dielectric layers that are laminated, a plurality of first internal electrode layers and a plurality of second internal electrode layers each laminated on a corresponding one of the plurality of dielectric layers, a first main surface and a second main surface opposed to each other in a lamination direction, a first end surface and a second end surface opposed to each other in a length direction perpendicular or substantially perpendicular to the lamination direction, and a first lateral surface and a second lateral surface opposed to each other in a width direction perpendicular or substantially perpendicular to the lamination direction and the length direction, a first external electrode on the first end surface, and a second external electrode on the second end surface. The multilayer body includes an inner layer portion where the plurality of first internal electrode layers and the plurality of second internal electrode layers are opposed to each other, and outer layer portions each including dielectric material. When defining a length in a direction parallel or substantially parallel to the lamination direction of the inner layer portion at a middle position in the width direction of the inner layer portion as a first length, and defining a length in a direction parallel or substantially parallel to the lamination direction of the inner layer portion at a position where a length from an end portion in the width direction of the inner layer portion in a direction parallel or substantially parallel to one other end portion in the width direction of the inner layer portion is about 0.3% or more and about 8.0% or less of a length in the width direction of the inner layer portion as a second length, the second length is longer than the first length. According to example embodiments of the present invention, multilayer ceramic capacitors each able to facilitate improvement in capacitance and improvement in reliability are provided. The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a multilayer ceramic capacitor according to an example embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line I-I in FIG. 1. FIG. 3 is a cross-sectional view taken along the line II-II in FIG. 1. FIG. 4 is a cross-sectional view taken along the line III-III in FIG. 1. FIG. 5A is a diagram show