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JP-7857083-B2 - Multilayer ceramic capacitor

JP7857083B2JP 7857083 B2JP7857083 B2JP 7857083B2JP-7857083-B2

Inventors

  • 水野 高太郎

Assignees

  • 太陽誘電株式会社

Dates

Publication Date
20260512
Application Date
20210302

Claims (6)

  1. A laminate comprising a plurality of ceramic layers stacked in a first axial direction, and a plurality of internal electrodes disposed between the plurality of ceramic layers, wherein the positions of the ends of the plurality of internal electrodes in a second axial direction perpendicular to the first axis are aligned with each other within a range of 0.5 μm in the second axial direction, A first side margin portion and a second side margin portion are located opposite each other in the second axial direction, comprising manganese or magnesium and silicon, with respect to the laminate. It is equipped with, When the first side margin portion and the second side margin portion are each divided into three equal parts in the second axial direction, and are partitioned into a first inner region in contact with the laminate, a first central region, and a first outer region, The total concentration of manganese and magnesium in the first outer region is higher than the total concentration of manganese and magnesium in the first central region, the total concentration of manganese and magnesium in the first central region is higher than the total concentration of manganese and magnesium in the first inner region, and the total concentration of manganese and magnesium in the first outer region is higher than the total concentration of manganese and magnesium in the plurality of ceramic layers. The manganese concentration in the first outer region is higher than the manganese concentration in the first inner region, and the magnesium concentration in the first outer region is higher than the magnesium concentration in the first inner region. A multilayer ceramic capacitor in which the silicon concentration in the first inner region is greater than or equal to the silicon concentration in the first central region, the silicon concentration in the first central region is greater than or equal to the silicon concentration in the first outer region, and the silicon concentration in the first inner region is higher than the silicon concentration in the plurality of ceramic layers.
  2. A multilayer ceramic capacitor according to claim 1, A multilayer ceramic capacitor in which the silicon concentration in the first inner region is higher than the silicon concentration in the first central region, and the silicon concentration in the first central region is higher than the silicon concentration in the first outer region.
  3. A multilayer ceramic capacitor according to claim 1 or 2, A multilayer ceramic capacitor in which the dimensions of the first side margin portion and the second side margin portion in the second axial direction are 13 μm or less.
  4. A multilayer ceramic capacitor according to any one of claims 1 to 3, The laminated body is A capacitance forming section comprising the plurality of ceramic layers and the plurality of internal electrodes, It comprises manganese or magnesium, and silicon, and has a first cover portion and a second cover portion that face each other in the first axial direction with respect to the volume forming portion, When the first cover portion and the second cover portion are each divided into three equal parts in the first axial direction, and are partitioned into a second inner region in contact with the volume forming portion, a second central region, and a second outer region, The total concentration of manganese and magnesium in the second outer region is higher than the total concentration of manganese and magnesium in the second central region, the total concentration of manganese and magnesium in the second central region is higher than the total concentration of manganese and magnesium in the second inner region, and the total concentration of manganese and magnesium in the first outer region is higher than the total concentration of manganese and magnesium in the plurality of ceramic layers. The manganese concentration in the second outer region is higher than the manganese concentration in the second inner region, and the magnesium concentration in the second outer region is higher than the magnesium concentration in the second inner region. A multilayer ceramic capacitor in which the silicon concentration in the second inner region is greater than or equal to the silicon concentration in the second central region, the silicon concentration in the second central region is greater than or equal to the silicon concentration in the second outer region, and the silicon concentration in the second inner region is higher than the silicon concentration in the plurality of ceramic layers.
  5. A multilayer ceramic capacitor according to any one of claims 1 to 4, A multilayer ceramic capacitor in which the thickness of each of the plurality of internal electrodes in the first axial direction is 0.4 μm or less.
  6. A multilayer ceramic capacitor according to claim 1, The silicon concentration in the first inner region is the same as the silicon concentration in the first central region and the silicon concentration in the first outer region, and is higher than the silicon concentration in the plurality of ceramic layers. A multilayer ceramic capacitor in which the silicon concentration is uniform throughout the entire first inner region, the silicon concentration is uniform throughout the entire first central region, and the silicon concentration is uniform throughout the entire first outer region.

Description

This invention relates to a multilayer ceramic capacitor equipped with a side margin. A multilayer ceramic capacitor is known in which a side margin is added to the side surface of a laminate in which ceramic layers and internal electrodes are stacked (see, for example, Patent Document 1). This configuration is advantageous for miniaturizing and increasing the capacitance of multilayer ceramic capacitors because the thin side margin reliably protects the side surface of the laminate where the internal electrodes are exposed. From the perspective of increasing the intersection area of the internal electrodes, a thinner side margin is preferable. On the other hand, in multilayer ceramic capacitors, when a high voltage is applied to the internal electrodes, electrostriction can occur due to the ferroelectricity of the ceramic layer. If the side margin is thin, structural defects such as cracks are more likely to occur due to stress caused by electrostriction, making it difficult to obtain sufficient breakdown voltage characteristics. In contrast, a technique is known in which elements such as Mg and Mn are added to the region located between the internal electrode and the side surface to promote the densification of the ceramic (see, for example, Patent Document 2). Japanese Patent Publication No. 2012-209539Japanese Patent Publication No. 2018-063969 This is a perspective view of a multilayer ceramic capacitor according to the first embodiment of the present invention.This is a cross-sectional view of the multilayer ceramic capacitor along the line A-A' in Figure 1.This is a cross-sectional view of the multilayer ceramic capacitor along the line B-B' in Figure 1.This flowchart shows the manufacturing method for the multilayer ceramic capacitor described above.This is a perspective view showing the manufacturing process of the multilayer ceramic capacitor described above.This is a perspective view showing the manufacturing process of the multilayer ceramic capacitor described above.This is a perspective view showing the manufacturing process of the multilayer ceramic capacitor described above.This is a cross-sectional view of a multilayer ceramic capacitor according to a second embodiment of the present invention. Embodiments of the present invention will be described below with reference to the drawings. The X, Y, and Z axes shown in the drawing are mutually orthogonal and define the coordinate system to which the multilayer ceramic capacitor 10 belongs. <First Embodiment> Figures 1 to 3 show a multilayer ceramic capacitor 10 according to a first embodiment of the present invention. Figure 1 is a perspective view of the multilayer ceramic capacitor 10. Figure 2 is a cross-sectional view of the multilayer ceramic capacitor 10 along the line A-A' in Figure 1. Figure 3 is a cross-sectional view of the multilayer ceramic capacitor 10 along the line B-B' in Figure 1. The multilayer ceramic capacitor 10 comprises a ceramic body 11, a first external electrode 14, and a second external electrode 15. The ceramic body 11 is constructed as a substantially hexahedron having a first and second end face perpendicular to the X-axis direction, a first and second side face perpendicular to the Y-axis direction, and a first and second main face perpendicular to the Z-axis direction. The edges connecting each face of the ceramic body 11 are, for example, rounded. The multilayer ceramic capacitor 10 has, for example, the following dimensions: The maximum dimension of the multilayer ceramic capacitor 10 in the X-axis direction is, for example, 0.2 mm to 3.5 mm. The maximum dimension of the multilayer ceramic capacitor 10 in the Y-axis direction is, for example, 0.1 mm to 2.8 mm. The maximum dimension of the multilayer ceramic capacitor 10 in the Z-axis direction is, for example, 0.1 mm to 2.8 mm. Each external electrode 14 and 15 covers the end face of the ceramic body 11 and faces the ceramic body 11 in the X-axis direction. The external electrodes 14 and 15 shown in Figure 1 extend from the end face of the ceramic body 11 to the main surface and side surface. Note that the shape of the external electrodes 14 and 15 is not limited to the example shown in Figure 1. The external electrodes 14 and 15 are formed from a good electrical conductor. Examples of good electrical conductors forming the external electrodes 14 and 15 include metals or alloys primarily composed of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), and gold (Au). The ceramic substrate 11 comprises a laminate 16, a first side margin portion 17a, and a second side margin portion 17b. The first side margin portion 17a and the second side margin portion 17b face each other in the Y-axis direction, with the laminate 16 in between. The first side margin portion 17a and the second side margin portion 17b each cover the laminate 16 from the Y-axis direction. The laminate 16 has a first side surface S1 and a second side surface S2 perpendic