Laminated type electron component

Abstract

To provide a multilayer ceramic capacitor that can be reduced in size and thickness.SOLUTION: A multilayer ceramic capacitor 10 includes a multilayer body 2, a base electrode 3, and an external electrode 4. The multilayer body has a plurality of internal electrodes 5 and a plurality of dielectric layers 6 alternately stacked, and has a first surface 7a and a second surface 7b facing each other in a stacking direction. A base electrode is located on the first surface. The external electrode includes a first external electrode 4a connected to a first internal electrode 5a exposed to a surface of the multilayer body among the plurality of internal electrodes and connected to the base electrode, and a second external electrode 4b connected to a second internal electrode 5b exposed to the surface of the multilayer body among the plurality of internal electrodes and connected to the base electrode, and an average particle diameter of metal particles included in the base electrode is larger than the average particle diameter of the metal particles included in the first internal electrode.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A multilayer ceramic capacitor, which is an example of a multilayer electronic component, is composed of a laminate in which multiple internal electrodes and multiple dielectric layers are alternately stacked, and external electrodes located on the surface of the laminate. By forming the external electrodes by direct plating, the thickness of the external electrodes can be reduced, which makes it possible to make the multilayer ceramic capacitor smaller and thinner without reducing the capacitance (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-212298 Summary of the Invention

[0004] The multilayer electronic component of the present disclosure includes a laminate having a plurality of alternatingly stacked internal electrodes and a plurality of dielectric layers, and having a first surface and a second surface facing each other in the stacking direction, a base electrode located on the first surface, and an external electrode connected to a first internal electrode exposed on the surface of the laminate among the plurality of internal electrodes and also connected to the base electrode, wherein the average particle size of the metal particles contained in the base electrode is larger than the average particle size of the metal particles contained in the first internal electrode. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a perspective view showing a multilayer ceramic capacitor according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing an element part of the multilayer ceramic capacitor of FIG. [Figure 3]FIG. 3 is a diagram showing an example of a cross section taken along the cross section line III-III in FIG. [Figure 4] 3 is a diagram showing another example of a cross section taken along the cross section line III-III in FIG. 1. FIG. [Figure 5] FIG. 4 is an enlarged cross-sectional view showing a portion V in FIG. 3. [Figure 6] FIG. 4 is an enlarged cross-sectional view showing a portion VI of FIG. 3 in an enlarged manner. [Figure 7] 6 is an electron microscope photograph illustrating measurement of the particle size of metal particles contained in the second portion of the external electrode and the base electrode. [Figure 8] 5 is an electron microscope photograph illustrating measurement of the particle size of metal particles contained in the first portion of the external electrode and the internal electrode. [Figure 9] FIG. 4 is a perspective view showing a multilayer ceramic capacitor according to a second embodiment. [Figure 10] FIG. 10 is a perspective view showing an element part of the multilayer ceramic capacitor of FIG. [Figure 11] 10 is a diagram showing an example of a cross section taken along the cross section line XI-XI in FIG. 9. FIG. [Figure 12] 10 is a diagram showing an example of a cross section taken along the cross section line XII-XII in FIG. 9. FIG. [Figure 13] FIG. 2 is a perspective view illustrating a process for producing a base laminate. [Figure 14] FIG. 2 is a perspective view showing a base laminate. [Figure 15] 15 is a perspective view showing an element part precursor obtained by cutting the base laminate of FIG. 14. FIG. [Figure 16] FIG. 10 is a perspective view showing a multilayer ceramic capacitor according to a third embodiment. [Figure 17] FIG. 17 is a perspective view showing an element part of the multilayer ceramic capacitor of FIG. [Figure 18] 18 is a diagram showing an example of a cross section taken along the cross section line XVIII-XVIII in FIG. 16. FIG. [Figure 19] 19 is a diagram showing an example of a cross section taken along the cross section line XIX-XIX in FIG. 16. FIG. [Figure 20] FIG. 10 is a perspective view showing a multilayer ceramic capacitor according to a fourth embodiment. [Figure 21] FIG. 21 is a perspective view showing an element part of the multilayer ceramic capacitor of FIG. 20. [Figure 22] 22 is a diagram showing an example of a cross section taken along the cross section line XXII-XXII in FIG. 20. [Figure 23] 23 is a diagram showing an example of a cross section taken along the cross section line XXIII-XXIII in FIG. 20. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, embodiments of the multilayer electronic component of the present disclosure will be described with reference to the drawings. Hereinafter, a multilayer ceramic capacitor will be described as an example of a multilayer electronic component. However, the multilayer electronic component of the present disclosure is not limited to a multilayer ceramic capacitor and can be applied to various other multilayer electronic components, such as multilayer piezoelectric elements, multilayer thermistor elements, multilayer chip coils, and ceramic multilayer substrates. The drawings used in the following description are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones. In this specification, for convenience, a Cartesian coordinate system xyz is defined in some drawings. The x-axis direction is also referred to as the length direction. The y-axis direction is also referred to as the width direction. The z-axis direction is also referred to as the height direction or stacking direction. Hereinafter, the positive side of the z-axis direction is defined as the upper side, and terms such as upper surface and lower surface may be used.

[0007] The following embodiments will be described with a focus on differences from the embodiments described earlier. For matters not specifically mentioned, the descriptions of the embodiments described earlier may be used or inferred from the descriptions of the embodiments described earlier. Furthermore, the description of one embodiment may be applied to the other embodiments as long as no contradictions arise.

[0008] FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to a first embodiment, and FIG. 2 is a perspective view showing an element component of the multilayer ceramic capacitor shown in FIG. 1. FIG. 3 is a view showing an example of a cross section taken along the line III-III in FIG. 1, and FIG. 4 is a view showing another example of a cross section taken along the line III-III in FIG. 1. FIG. 5 is an enlarged cross section showing a portion V in FIG. 3, and FIG. 6 is an enlarged cross section showing a portion VI in FIG. 3. FIG. 7 is an electron microscope photograph illustrating measurement of the particle size of metal particles contained in the second portion of the external electrode and the base electrode. FIG. 8 is an electron microscope photograph illustrating measurement of the particle size of metal particles contained in the first portion of the external electrode and the internal electrode. In FIG. 2, the base electrode and the ends of the internal electrodes exposed on the surface of the laminate are hatched for ease of illustration. FIG. 5 is a view showing the portion V in the cross section of the multilayer ceramic capacitor according to the first embodiment, but also shows a portion corresponding to the portion V in the cross sections of the multilayer ceramic capacitors according to the second to fourth embodiments. The same applies to FIG. 6. 5 and 6, some of the metal particles contained in the external electrodes are shown, but the metal particles contained in the base electrode and internal electrodes are not shown.

[0009] 1 to 3, the multilayer ceramic capacitor 10 in accordance with the first embodiment includes an element component 1 and a plurality of external electrodes 4. As shown in Fig. 2, the element component 1 includes a laminate 2 and a plurality of base electrodes 3. The multilayer ceramic capacitor 10 may be a thin multilayer ceramic capacitor in which the dimension T in the height direction (z-axis direction) is smaller than the dimension L in the length direction (x-axis direction) and the dimension W in the width direction (y-axis direction).

[0010] The laminate 2 is formed by alternately stacking a plurality of internal electrodes 5 and a plurality of dielectric layers 6. As shown in FIG. 2, the laminate 2 may have a substantially rectangular parallelepiped shape. The laminate 2 has a first surface 7a and a second surface 7b that face each other in the stacking direction (z-axis direction) of the plurality of internal electrodes 5 and the plurality of dielectric layers 6. The laminate 2 has a first end surface 8a and a second end surface 8b that face each other in the length direction (x-axis direction) perpendicular to the stacking direction, and a first side surface 9a and a second side surface 9b that face each other in the width direction (y-axis direction) perpendicular to the stacking direction and the length direction. Hereinafter, the first surface 7a and the second surface 7b may be collectively referred to as the main surfaces 7a and 7b, the first end surface 8a and the second end surface 8b may be collectively referred to as the end surfaces 8a and 8b, and the first side surface 9a and the second side surface 9b may be collectively referred to as the side surfaces 9a and 9b. The main surfaces 7a and 7b may be perpendicular to the stacking direction. The end faces 8a and 8b may be perpendicular to the length direction, and the side faces 9a and 9b may be perpendicular to the width direction.

[0011] The dielectric layer 6 is made of a ceramic material whose main component is, for example, BaTiO3 (barium titanate), CaTiO3 (calcium titanate), SrTiO3 (strontium titanate), BaZrO3 (barium zirconate), or CaZrO3 (calcium zirconate). The ceramic material may contain a secondary component such as, for example, an Mn (manganese) compound, an Mg (magnesium) compound, an Si (silicon) compound, a Co (cobalt) compound, an Ni compound, or a rare earth compound. The dielectric layer 6 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0012] As shown in Figures 2 and 3, the multiple internal electrodes 5 include multiple first internal electrodes 5a and multiple second internal electrodes 5b. The first internal electrodes 5a have ends exposed at the first end surface 8a. The second internal electrodes 5b have ends exposed at the second end surface 8b. The first internal electrodes 5a and the second internal electrodes 5b have polarities opposite to each other. In other words, when the first internal electrodes 5a have a first polarity, the second internal electrodes 5b have a second polarity different from the first polarity.

[0013] The internal electrodes 5 are made of a metal material containing, for example, Ni (nickel), Cu (copper), Sn (tin), etc. as a main component. The internal electrodes 5 may contain, for example, a ceramic material such as BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The internal electrodes 5 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0014] As shown in Fig. 3, the laminate 2 may include a capacitance-forming portion 2a and cover portions 2b and 2c. The capacitance-forming portion 2a is formed by alternately stacking a plurality of internal electrodes 5 and a plurality of dielectric layers 6, and forms a capacitance. The cover portions 2b and 2c are located at both ends of the capacitance-forming portion 2a in the stacking direction. The cover portions 2b and 2c are each made of one or more dielectric layers and do not necessarily form a capacitance.

[0015] Although not shown, the cover portions 2b and 2c may have a configuration including two or more dielectric layers and one or more dummy layers (less than the number of dielectric layers) positioned therebetween. Each dummy layer may include multiple dummy electrodes. The multiple dummy electrodes on each dummy layer may overlap the multiple base electrodes 3 in a planar perspective view. In other words, the multiple dummy electrodes may be provided in the same number, at approximately the same positions, and with approximately the same shapes (including dimensions) as the multiple base electrodes 3. The multiple dummy electrodes may be exposed to the outside from either the end faces 8a and 8b or the side faces 9a and 9b of the laminate 2. The multiple external electrodes 4 may be connected to the exposed portions. The multiple dummy electrodes do not need to form capacitance. The material (components) and microstructure of the multiple dummy electrodes may be the same as those of the base electrodes 3 or the internal electrodes 5, or may be different from either. For convenience, the cover portions 2b and 2c may be expressed as if they were composed only of dielectric layers, ignoring the presence or absence of dummy layers.

[0016] The cover portions 2b and 2c (their dielectric layers) are made of a ceramic material whose main component is, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The cover portions 2b and 2c may be made of the same ceramic material as the ceramic material that makes up the dielectric layer 6.

[0017] The plurality of base electrodes 3 include a first base electrode 3a and a second base electrode 3b. The first base electrode 3a is located closer to the first end face 8a on the first surface 7a. The second base electrode 3b is located closer to the second end face 8b on the first surface 7a.

[0018] The first base electrode 3a and the second base electrode 3b are spaced apart from each other, as shown in Figures 2 and 3. The dimension of the first base electrode 3a in the longitudinal direction (x-axis direction) may be approximately 5 to 30% of the dimension of the laminate 2 in the longitudinal direction. The same applies to the second base electrode 3b. The edge of the first base electrode 3a on the first end face 8a side may overlap the edge of the first surface 7a on the first end face 8a side in a planar view. The edge of the second base electrode 3b on the second end face 8b side may overlap the edge of the first surface 7a on the second end face 8b side in a planar view.

[0019] The base electrode 3 is made of a metal material containing, for example, Ni, Cu, Sn, or the like as a main component. The base electrode 3 may be made of the same metal material as the metal material constituting the internal electrodes 5. The base electrode 3 may contain, for example, a ceramic material such as BaTiO3, CaTiO3, SrTiO3, BaZrO3, or CaZrO3. In this case, it becomes easier to improve the adhesion between the base electrode 3 and the laminate 2. The base electrode 3 may be thicker than one layer of the internal electrode 5. The base electrode 3 may have a thickness of, for example, about 0.5 to 2.0 μm.

[0020] The base electrode 3 may include a third base electrode 3c and a fourth base electrode 3d. The third base electrode 3c is located closer to the first end face 8a on the second surface 7b. The fourth base electrode 3d is located closer to the second end face 8b on the second surface 7b. The third base electrode 3c may have the same configuration as the first base electrode 3a, except that it is located on the second surface 7b. The fourth base electrode 3d may have the same configuration as the second base electrode 3b, except that it is located on the second surface 7b.

[0021] As shown in FIGS. 1 and 3, the plurality of external electrodes 4 include a first external electrode 4a and a second external electrode 4b.

[0022] The first external electrode 4a is located from the first end face 8a to at least the first surface 7a, and is connected to the plurality of first internal electrodes 5a and the first base electrode 3a. The first external electrode 4a may cover the first base electrode 3a.

[0023] The first external electrode 4a may be located from the first end face 8a across the first face 7a and the second face 7b, and may be connected to the plurality of first internal electrodes 5a, the first base electrode 3a, and the third base electrode 3c. The first external electrode 4a may cover the first base electrode 3a and the third base electrode 3c. The first external electrode 4a may be located from the first end face 8a across the first face 7a, the second face 7b, the first side face 9a, and the second side face 9b.

[0024] The second external electrode 4b is located from the second end face 8b to at least the first face 7a, and is connected to the second internal electrodes 5b and the second base electrode 3b. The second external electrode 4b may cover the second base electrode 3b.

[0025] The second external electrode 4b may be located from the second end face 8b across the first face 7a and the second face 7b, and may be connected to the plurality of second internal electrodes 5b, the second base electrode 3b, and the fourth base electrode 3d. The second external electrode 4b may cover the second base electrode 3b and the fourth base electrode 3d. The second external electrode 4b may be located from the second end face 8b across the first face 7a, the second face 7b, the first side face 9a, and the second side face 9b.

[0026] The external electrodes 4 may be plating layers formed by direct plating on the laminate 2. Direct plating is a method of applying at least a portion of a plating layer to a surface where no underlying conductor layer is located (here, the surface of the laminate 2 made of a dielectric). By employing direct plating, the thickness of the external electrodes 4 can be reduced. As a result, the multilayer ceramic capacitor 10 can be made smaller without reducing the capacitance of the multilayer ceramic capacitor 10. The thickness of the external electrodes 4 may be, for example, approximately 5 to 20 μm. The external electrodes 4 can be formed by plating methods such as electroless plating and electrolytic plating. The external electrodes 4 may be made of a metal material containing Cu, Ni, Sn, or the like as a main component.

[0027] In the description of the embodiments, the term "plating layer" may be replaced with the term "metal layer" that does not contain ceramic material. The base electrode 3 and the internal electrodes 5 (or, from another perspective, the conductive paste that forms these electrodes) often contain ceramic material. On the other hand, the external electrode 4 does not substantially contain (intentionally contains) ceramic material.

[0028] The external electrode 4 may be composed of two or more plating layers. As shown in Fig. 4, the external electrode 4 may be composed of first layers 4aa, 4ba connected to the base electrode 3 and the internal electrode 5, and second layers 4ab, 4bb covering the first layers 4aa, 4ba. The external electrode 4 may be composed of first layers 4aa, 4ba connected to the base electrode 3 and the internal electrode 5, second layers 4ab, 4bb covering the first layers 4aa, 4ba, and a third layer (not shown) covering the second layers 4ab, 4bb. In this case, the first layers 4aa, 4ba may be formed by direct plating.

[0029] The first external electrode 4a and the second external electrode 4b each have a first portion 41 and a second portion 42. The first portion 41 is located on the end surfaces 8a and 8b of the laminate 2 and is connected to the multiple first internal electrodes 5a or the multiple second internal electrodes 5b. The second portion 42 is located on the first surface 7a of the laminate 2 and is connected to the first base electrode 3a or the second base electrode 3b. The second portion 42 may cover the first base electrode 3a or the second base electrode 3b. The second portion 42 may also be located on the second surface 7b and be further connected to the third base electrode 3c or the fourth base electrode 3d. The first portion 41 is also referred to as an end surface electrode portion. The second portion 42 is also referred to as a main surface electrode portion.

[0030] The end surface electrode portion 41 of the first external electrode 4a is located on the first end surface 8a and is connected to end portions of the multiple first internal electrodes 5a exposed at the first end surface 8a. The main surface electrode portion 42 of the first external electrode 4a is located on the first surface 7a and is connected to the first base electrode 3a. The main surface electrode portion 42 of the first external electrode 4a may cover the first base electrode 3a. The main surface electrode portion 42 of the first external electrode 4a may be located on the first surface 7a and the second surface 7b and be connected to the first base electrode 3a and the third base electrode 3c. The main surface electrode portion 42 of the first external electrode 4a may cover the first base electrode 3a and the third base electrode 3c.

[0031] The end surface electrode portion 41 of the second external electrode 4b is located on the second end surface 8b and is connected to end portions of the multiple second internal electrodes 5b that are exposed at the second end surface 8b. The principal surface electrode portion 42 of the second external electrode 4b is located on the first surface 7a and is connected to the second base electrode 3b. The principal surface electrode portion 42 of the second external electrode 4b may cover the second base electrode 3b. The principal surface electrode portion 42 of the second external electrode 4b may be located on both the first surface 7a and the second surface 7b and be connected to the second base electrode 3b and the fourth base electrode 3d. The principal surface electrode portion 42 of the second external electrode 4b may cover the second base electrode 3b and the fourth base electrode 3d.

[0032] The external electrodes 4 contain metal particles M. The multilayer ceramic capacitor 10 is configured such that the average particle size of the metal particles M contained in the end surface electrode portions 41 is smaller than the average particle size of the metal particles M contained in the main surface electrode portions 42. The multilayer ceramic capacitor 10 may be mounted such that the first surface 7a or the second surface 7b faces the mounting surface of a circuit board. However, the main surface electrode portions 42 extending substantially parallel to the mounting surface are susceptible to stress during mounting, making them susceptible to cracking. Because the average particle size of the metal particles contained in the main surface electrode portions 42 of the multilayer ceramic capacitor 10 is relatively large, the grain boundary area (grain boundary area of ​​the metal particles M), which is likely to be the starting point of cracks, can be reduced, thereby improving the mechanical strength of the main surface electrode portions 42. As a result, the risk of cracks occurring in the main surface electrode portions 42 can be reduced, and the reliability of the multilayer ceramic capacitor 10 can be improved.

[0033] Furthermore, since the average particle size of the metal particles M contained in the end surface electrode portions 41 of the multilayer ceramic capacitor 10 is relatively small, it is possible to increase the contact area between the metal particles M contained in the end surface electrode portions 41 and the metal particles contained in the internal electrodes 5. As a result, the end surface electrode portions 41 and the internal electrodes 5 can be well connected, and the electrical characteristics of the multilayer ceramic capacitor 10 can be improved.

[0034] In an embodiment in which the external electrode 4 has multiple metal layers (plated layers) as shown in FIG. 4 , the end surface electrode portion 41 and the main surface electrode portion 42 may be part of the metal layer closest to the laminate 2, part of two or more metal layers selected from the laminate 2 side (e.g., two layers on the laminate 2 side in a three-layer structure), or part of all metal layers. In other words, the requirement that the average particle size of the metal particles M on the end surface side be smaller than the average particle size of the metal particles M on the main surface side may be satisfied only in the layer closest to the laminate 2, or in two or more (not all) layers selected from the laminate 2 side, or in all layers. Note that, unlike the above, it may be a mandatory requirement that this requirement be satisfied in the layer closest to the laminate 2, or in two or more (not all) metal layers selected from the laminate 2 side, or in all layers.

[0035] Furthermore, when the end surface electrode portion 41 and the main surface electrode portion 42 are assumed to be part of two or more metal layers, the fact that the average particle size of the metal particles M on the end surface side is smaller than the average particle size of the metal particles M on the main surface side may be true for each of the two or more metal layers in question, and / or may be true for the average particle size in the entire two or more metal layers.

[0036] The explanations in the paragraphs before and before may be applied not only to the fact that the average particle size of the metal particles M on the end face side is smaller than the average particle size of the metal particles M on the main surface side, but also to other particle size-related matters, unless contradictions arise. For example, the fact that the particle size becomes smaller or larger as it approaches the laminate 2 (described later) may only be true for the layer closest to the laminate 2, or for two or more layers (not all layers) selected from the laminate 2 side, or for all layers. Alternatively, either of these may be a required requirement. The explanations of specific examples of the average particle size (μm) or materials may apply only to the layer closest to the laminate 2, or for two or more layers (not all layers) selected from the laminate 2 side, or for all layers.

[0037] The average particle size of the metal particles M contained in the end surface electrode portion 41 may be, for example, 0.3 to 0.8 μm or 0.5 to 0.6 μm. The average particle size of the metal particles M contained in the main surface electrode portion 42 may be, for example, 0.3 to 1.3 μm or approximately 0.6 to 1.0 μm.

[0038] The base electrode 3 and the internal electrode 5 may be primarily composed of Ni, and the external electrode 4 may be primarily composed of Cu. In this case, metal particles made of a Cu-Ni alloy are formed in the region near the interface between the element component 1 and the external electrode 4, and the average particle size of these metal particles can be made relatively large. As a result, the mechanical strength of the main surface electrode portion 42 is improved, and it is easy to increase the adhesion between the element component 1 and the external electrode 4.

[0039] The average particle size of the metal particles M at a position P in the end surface electrode portion 41, which is a predetermined distance L1 away from the surface facing the laminate 2, may be smaller than the average particle size of the metal particles M at a position Q in the main surface electrode portion 42, which is a predetermined distance L1 away from the surface facing the laminate 2 (see FIGS. 5 and 6 ). The predetermined distance L1 may be, for example, 0.5 to 1.5 μm, or 1 μm. Because the average particle size of the metal particles M contained in the region of the main surface electrode portion 42 near the base electrode 3 is relatively large, the risk of cracks occurring in this region can be reduced, thereby improving the reliability of the multilayer ceramic capacitor 10. Furthermore, because the average particle size of the metal particles M contained in the region of the end surface electrode portion 41 near the internal electrode 5 is relatively small, the end surface electrode portion 41 and the internal electrode 5 can be well connected, thereby improving the electrical characteristics of the multilayer ceramic capacitor 10.

[0040] In other words, the average particle size of the metal particles M at position P is the average particle size of the multiple metal particles M that span across position P. Similarly, the average particle size of the metal particles M at position Q is the average particle size of the multiple metal particles M that span across position Q. The same applies to the average particle size of the metal particles at positions S or R, which will be described later.

[0041] The average particle size of the metal particles M contained in the end surface electrode portion 41 may be 1.1 times or more, 1.5 times or more, or 2 times or more, or 5 times or less, 3 times or less, or 2.7 times or less, of the average particle size of the metal particles M contained in the main surface electrode portion 42. The above lower and upper limits may be combined arbitrarily. For example, the average particle size of the metal particles M contained in the end surface electrode portion 41 may be 1.1 to 2.7 times the average particle size of the metal particles M contained in the main surface electrode portion 42. In this case, the end surface electrode portion 41 and the internal electrode 5 can be better connected, and the mechanical strength of the main surface electrode portion 42 can be further improved. The above lower and / or upper limits may be used to refer to the ratio of the average particle size of the metal particles M at position P to the average particle size of the metal particles M at position Q.

[0042] The particle size of the metal particles M contained in the end surface electrode portions 41 may decrease toward the laminate 2. In this case, the end surface electrode portions 41 and the internal electrodes 5 can be connected better, and the electrical characteristics of the multilayer ceramic capacitor 10 can be further improved. In addition, the grain boundary area in the region near the outer surface of the end surface electrode portion 41 (the surface opposite to the surface facing the laminate 2) can be reduced. As a result, the risk of cracks occurring in the region near the outer surface of the end surface electrode portion 41 can be reduced, and the moisture resistance of the multilayer ceramic capacitor 10 can be prevented from decreasing.

[0043] Note that the fact that the particle size of the metal particles M decreases toward the laminate 2 does not necessarily mean that the particle sizes of all the metal particles M strictly meet this relationship. For example, it is sufficient that the particle sizes of 3 or more, 10 or more, or 50 or more of the metal particles M contained in the end surface electrode portion 41 are measured and meet this relationship. Furthermore, for example, in the particle size measurement results for a predetermined number of metal particles M, 60% or more or 80% or more of the metal particles M may meet this relationship. In other words, it may be possible to extract 60% or more or 80% or more of the metal particles M meeting this relationship from a predetermined number of randomly selected metal particles M. The larger the predetermined number, the more accurate the determination of whether the relationship is met. The predetermined number may be, for example, 10, 50, or 100. The positions of the metal particles M may be compared based on the geometric center. Furthermore, for example, the end surface electrode portion 41 may be divided into two equal regions in the thickness direction, and it may be determined that the relationship is met if the average particle size in the region closer to the laminate 2 is smaller than the average particle size in the region farther from the laminate 2. Instead of dividing into two, it may be divided into three or five equal parts. Whether a metal particle M belongs to which region may be determined based on the geometric center of the metal particle M. In any measurement and determination, particles that are extremely small compared to surrounding particles may be ignored in determining whether the relationship is established.

[0044] The particle size of the metal particles M contained in the principal-surface electrode portion 42 may increase toward the laminate 2. In this case, since the average particle size of the metal particles M contained in the region of the principal-surface electrode portion 42 near the base electrode 3 is relatively large, it is possible to further reduce the risk of cracks occurring in this region, which is close to the laminate 2 and is likely to affect the electrical characteristics, and to further improve the reliability of the multilayer ceramic capacitor 10. Note that, "the particle size of the metal particles M increases toward the laminate 2," it is not necessarily the case that the particle sizes of all the metal particles M strictly satisfy this relationship. In this regard, the explanation in the previous paragraph may be used. For example, it is sufficient that the particle sizes of 3 or more, 10 or more, or 50 or more of the metal particles M contained in the principal-surface electrode portion 42 are measured and satisfy this relationship.

[0045] The multilayer ceramic capacitor 10 may be configured such that the average particle size of the metal particles contained in the base electrode 3 is larger than the average particle size of the metal particles contained in the internal electrode 5. Because the average particle size of the metal particles contained in the base electrode 3 is relatively large, the risk of cracks occurring in the region of the base electrode 3 near the external electrode 4 can be reduced, thereby improving the reliability of the multilayer ceramic capacitor 10. Furthermore, because the average particle size of the metal particles contained in the internal electrode 5 is relatively small, the contact area between the metal particles contained in the internal electrode 5 and the metal particles M contained in the external electrode 4 (end surface electrode portion 41) can be increased. As a result, the external electrode 4 and the internal electrode 5 can be well connected, and the electrical characteristics of the multilayer ceramic capacitor 10 can be improved.

[0046] The multilayer ceramic capacitor 10 may be configured such that the average particle size of the metal particles at a position S in the base electrode 3, which is a predetermined distance L' away from the surface opposite the surface facing the laminate 2, is larger than the average particle size of the metal particles at a position R in the internal electrode 5, which is the predetermined distance L' away from the surface (end faces 8a, 8b) of the laminate 2 (see FIGS. 5 and 6). The predetermined distance L' may be, for example, 0.5 to 1.5 μm, or 1 μm. Because the average particle size of the metal particles in the region of the base electrode 3 near the external electrode 4 (main-surface electrode portion 42) is relatively large, the risk of cracks occurring in this region can be reduced, thereby improving the reliability of the multilayer ceramic capacitor 10. Furthermore, because the average particle size of the metal particles in the region of the internal electrode 5 near the external electrode 4 (end face electrode portion 41) is relatively small, the internal electrode 5 and the external electrode 4 can be well connected, thereby improving the electrical characteristics of the multilayer ceramic capacitor 10.

[0047] Next, a method for measuring the particle sizes of the metal particles contained in the base electrode 3, the external electrode 4, and the internal electrode 5 will be described.

[0048] First, a cross section of the multilayer ceramic capacitor 10 was exposed using a focused ion beam scanning electron microscope (FIB-SEM), and an electron microscope photograph of the cross section was taken. FIGS. 7 and 8 show electron microscope photographs of the cross section of the multilayer ceramic capacitor 10 taken at a magnification of 15,000 times. FIG. 7 corresponds to an electron microscope photograph of portion V in FIG. 3, and B1 in FIG. 7 indicates the interface between the external electrode 4 (main surface electrode portion 42) and the base electrode 3. FIG. 8 corresponds to an electron microscope photograph of portion VI in FIG. 3, and B2 in FIG. 8 indicates the interface between the external electrode 4 (end surface electrode portion 41) and the laminate 2. In this measurement, a Helios 5UC manufactured by Thermo Fisher Scientific was used as the FIB-SEM, and the analysis conditions were an acceleration voltage of 30 kV and a probe current of 80 pA.

[0049] Next, an image analysis program is used to draw boundary lines along the outlines of the metal particles on the electron microscope photographs of FIGS. 7 and 8, as shown by the dashed lines in FIGS. 7 and 8. To measure the particle size of the metal particles, the area of ​​the region surrounded by the boundary lines is calculated, and the circle-equivalent diameter of that area is taken as the particle size of the metal particles. The image analysis program may be an existing image analysis program. To calculate the average particle size of the metal particles contained in the main-surface electrode portion 42 of the external electrode 4, the particle sizes of N (N is a natural number) metal particles contained in the main-surface electrode portion 42 are calculated, and the arithmetic mean value of these particles is taken as the average particle size of the metal particles. N may be, for example, approximately 3 to 15, or may be approximately 10. The same applies to the average particle size of the metal particles contained in the end-surface electrode portion 41, the base electrode 3, and the internal electrode 5.

[0050] N may be greater than the above. For example, it may be 20, 50, or 100. The average grain size may be measured by analyzing the entire cross section of the target electrode (or portion or region), or it may be the average value of grain sizes measured by analyzing multiple partial regions of the cross section. The multiple partial regions may be, for example, three or more or five or more, have the same approximate area, and may be equally spaced in the left-right direction and / or the thickness direction. The average grain size may be a value in a single cross section at a specific position (e.g., a representative position such as the center) of the target (e.g., electrode) in a direction perpendicular to the cross section, or may be the average value in multiple cross sections (e.g., three or more or five or more) obtained by equally dividing the target. In the latter case, if it is difficult to equally divide a single target, measurements may be performed on multiple cross sections corresponding to the multiple cross sections obtained by the above-mentioned equal division of multiple multilayer ceramic capacitors 10 intended to have the same configuration, and the average value may be obtained. The same applies to other properties or index values, in that a cross section at such a specific position may be referenced, or an average value may be obtained by referencing a plurality of cross sections.

[0051] Next, a multilayer ceramic capacitor according to a second embodiment of the present disclosure will be described. Fig. 9 is a perspective view showing the multilayer ceramic capacitor of the second embodiment, Fig. 10 is a perspective view showing an element component of the multilayer ceramic capacitor of Fig. 9, Fig. 11 is a cross-sectional view taken along the cutting line XI-XI in Fig. 9, and Fig. 12 is a cross-sectional view taken along the cutting line XII-XII in Fig. 9. In Fig. 10, for ease of illustration, the base electrodes and the ends of the internal electrodes exposed on the surface of the laminate are hatched.

[0052] 9 to 12, the multilayer ceramic capacitor 10A of this preferred embodiment includes an element component 11 and a plurality of external electrodes 14. As shown in Fig. 2, the element component 11 includes a laminate 12 and a plurality of base electrodes 13. The multilayer ceramic capacitor 10A may be a thin multilayer ceramic capacitor in which the dimension T in the height direction (z-axis direction) is smaller than the dimension L in the length direction (x-axis direction) and smaller than the dimension W in the width direction (y-axis direction).

[0053] The laminate 12 is formed by alternately stacking a plurality of internal electrodes 15 and a plurality of dielectric layers 16. As shown in FIG. 10, the laminate 12 may have a substantially rectangular parallelepiped shape. The laminate 12 has a first surface 17a and a second surface 17b that face each other in the stacking direction (z-axis direction) of the plurality of internal electrodes 15 and the plurality of dielectric layers 16. The laminate 2 has a first side surface 18a and a second side surface 18b that face each other in the length direction (x-axis direction) perpendicular to the stacking direction, and a third side surface 18c and a fourth side surface 18d that face each other in the width direction (y-axis direction) perpendicular to the stacking direction and the length direction. Hereinafter, the first surface 17a and the second surface 17b may be collectively referred to as main surfaces 17a and 17b, and the first side surface 18a, the second side surface 18b, the third side surface 18c, and the fourth side surface 18d may be collectively referred to as side surfaces 18a to 18d. The main surfaces 17a and 17b may be perpendicular to the stacking direction, the first side surface 18a and the second side surface 18b may be perpendicular to the length direction, and the third side surface 18c and the fourth side surface 18d may be perpendicular to the width direction.

[0054] As shown in Figures 10 and 11, the laminate 12 has a first corner 19a extending from the first side surface 18a to the third side surface 18c, a second corner 19b extending from the second side surface 18b to the fourth side surface 18d, a third corner 19c extending from the first side surface 18a to the fourth side surface 18d, and a fourth corner 19d extending from the second side surface 18b to the third side surface 18c.

[0055] The dielectric layer 16 is made of a ceramic material whose main component is, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, or CaZrO3. The ceramic material may contain a secondary component such as a Mn compound, an Mg compound, an Si compound, a Co compound, an Ni compound, or a rare earth compound. The dielectric layer 16 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0056] As shown in Fig. 12, the multiple internal electrodes 15 include multiple first internal electrodes 15a and multiple second internal electrodes 15b. The first internal electrodes 15a have ends exposed at a first corner 19a and a second corner 19b. The second internal electrodes 15b have ends exposed at a third corner 19c and a fourth corner 19d. The first internal electrodes 15a and the second internal electrodes 15b have polarities opposite to each other. In other words, when the first internal electrode 15a has a first polarity, the second internal electrode 15b has a second polarity different from the first polarity.

[0057] The internal electrodes 15 are made of a metal material containing, for example, Ni, Cu, Sn, etc. as a main component. The internal electrodes 15 may contain a ceramic material such as BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The internal electrodes 15 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0058] As shown in Fig. 12, the laminate 12 may include a capacitance-forming portion 12a and cover portions 12b and 12c. The capacitance-forming portion 12a is formed by alternately stacking a plurality of internal electrodes 15 and a plurality of dielectric layers 16, and forms a capacitance. The cover portions 12b and 12c are located at both ends of the capacitance-forming portion 12a in the stacking direction. The cover portions 12b and 12c are each made of one or more dielectric layers and do not necessarily form a capacitance.

[0059] The cover portions 12b and 12c (their dielectric layers) are made of a ceramic material whose main component is, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The cover portions 12b and 12c may be made of the same ceramic material as the ceramic material that makes up the dielectric layer 16.

[0060] The plurality of base electrodes 13 include a first base electrode 13a, a second base electrode 13b, a third base electrode 13c, and a fourth base electrode 13d.

[0061] The first base electrode 13a is located closer to the first corner 19a on the first surface 17a. In plan view, the first base electrode 13a may have a substantially rectangular shape. In addition, in plan view, a corner of the first base electrode 13a closer to the first corner 19a may overlap the first corner 19a.

[0062] The second base electrode 13b is located closer to the second corner 19b on the first surface 17a. In plan view, the second base electrode 13b may have a substantially rectangular shape. In addition, in plan view, a corner of the second base electrode 13b closer to the second corner 19b may overlap the second corner 19b.

[0063] The third base electrode 13c is located closer to the third corner 19c on the first surface 17a. In plan view, the third base electrode 13c may have a substantially rectangular shape. Furthermore, in plan view, a corner of the third base electrode 13c closer to the third corner 19c may overlap the third corner 19c.

[0064] The fourth base electrode 13d is located closer to the fourth corner 19d on the first surface 17a. In plan view, the fourth base electrode 13d may have a substantially rectangular shape. Furthermore, in plan view, a corner of the fourth base electrode 13d closer to the fourth corner 19d may overlap the fourth corner 19d.

[0065] The shape of the first base electrode 13a is not limited to a substantially rectangular shape, and may be a substantially sector shape (substantially quadrant) or a substantially right-angled triangle. In a plan view, the center of the substantially sector shape (substantially quadrant) of the first base electrode 13a may overlap the first corner 19a, or the right-angled apex of the substantially right-angled triangle may overlap the first corner 19a. The same applies to the second base electrode 13b, the third base electrode 13c, and the fourth base electrode 13d.

[0066] The base electrode 3 may include a fifth base electrode 13e, a sixth base electrode 13f, a seventh base electrode 13g, and an eighth base electrode 13h. The fifth base electrode 13e is located closer to the first corner 19a on the second surface 7b. The sixth base electrode 13f is located closer to the second corner 19b on the second surface 7b. The seventh base electrode 13g is located closer to the third corner 19c on the second surface 7b. The eighth base electrode 13h is located closer to the fourth corner 19d on the second surface 7b. The fifth base electrode 13e and the sixth base electrode 13f may have the same configuration as the first base electrode 13a and the second base electrode 13b, respectively, except that they are located on the second surface 7b. The seventh and eighth base electrodes 13g and 13h may have the same configuration as the third and fourth base electrodes 13c and 13d, respectively, except that they are located on the second surface 7b.

[0067] The plurality of external electrodes 14 include a first external electrode 14a, a second external electrode 14b, a third external electrode 14c, and a fourth external electrode 14d.

[0068] The first external electrode 14a is located from the first corner 19a across at least the first surface 17a and is connected to the plurality of first internal electrodes 15a and the first base electrode 13a. The first external electrode 14a may be located from the first corner 19a across the first surface 17a and the second surface 17b and connected to the plurality of first internal electrodes 15a, the first base electrode 13a, and the fifth base electrode 13e.

[0069] The second external electrode 14b is located from the second corner 19b across at least the first surface 17a and is connected to the plurality of first internal electrodes 15a and the second base electrode 13b. The second external electrode 14b may be located from the second corner 19b across the first surface 17a and the second surface 17b and connected to the plurality of first internal electrodes 15a, the second base electrode 13b, and the sixth base electrode 13f.

[0070] The third external electrode 14c is located from the third corner 19c across at least the first surface 17a and is connected to the plurality of second internal electrodes 15b and the third base electrode 13c. The third external electrode 14c may be located from the third corner 19c across the first surface 17a and the second surface 17b and connected to the plurality of second internal electrodes 15b, the third base electrode 13c, and the seventh base electrode 13g.

[0071] The fourth external electrode 14d is located from the fourth corner 19d across at least the first surface 17a and is connected to the plurality of second internal electrodes 15b and the fourth base electrode 13d. The fourth external electrode 14d may be located from the fourth corner 19d across the first surface 17a and the second surface 17b and connected to the plurality of second internal electrodes 15b, the fourth base electrode 13d, and the eighth base electrode 13h.

[0072] The external electrodes 14 may be plated layers. In this case, the thickness of the external electrodes 14 can be reduced. As a result, the size of the multilayer ceramic capacitor 10A can be reduced without reducing the capacitance of the multilayer ceramic capacitor 10A. The thickness of the external electrodes 14 may be, for example, about 5 to 20 μm. The external electrodes 14 can be formed using a plating method such as electroless plating or electrolytic plating. The external electrodes 14 may be made of a metal material containing Cu, Ni, Sn, or the like as a main component.

[0073] The external electrode 14 may be composed of two or more plating layers. For example, the external electrode 14 may be composed of a first layer connected to the base electrode 13 and the internal electrode 15 and a second layer covering the first layer, or may be composed of a first layer connected to the base electrode 13 and the internal electrode 15, a second layer covering the first layer, and a third layer covering the second layer.

[0074] The first external electrode 14a, the second external electrode 14b, the third external electrode 14c, and the fourth external electrode 14d each have a first portion 141 and a second portion 142. The first portion 141 is located on the side surfaces 18a to 18d and is connected to the first internal electrodes 5a or the second internal electrodes 5b. The second portion 142 is located on the first surface 17a and is connected to the first base electrode 13a, the second base electrode 13b, the third base electrode 13c, or the fourth base electrode 13d. The second portion 142 may completely cover the first base electrode 13a, the second base electrode 13b, the third base electrode 13c, or the fourth base electrode 13d. The second portion 142 may also be located on the second surface 17b and be further connected to the fifth base electrode 13e, the sixth base electrode 13f, the seventh base electrode 13g, or the eighth base electrode 13h. The first portion 141 is also referred to as an end surface electrode portion, and the second portion 142 is also referred to as a main surface electrode portion.

[0075] The end surface electrode portion 141 of the first external electrode 14a is located on the first side surface 18a and the third side surface 18c and is connected to the ends of the multiple first internal electrodes 15a that are exposed on the first side surface 18a and the third side surface 18c. The principal surface electrode portion 142 of the first external electrode 14a is located on the first surface 17a and is connected to the first base electrode 13a. The principal surface electrode portion 142 of the first external electrode 14a may cover the first base electrode 13a. The principal surface electrode portion 142 of the first external electrode 14a may be located on the first surface 17a and the second surface 17b and may be connected to the first base electrode 13a and the fifth base electrode 13e. The principal surface electrode portion 142 of the first external electrode 14a may cover the first base electrode 13a and the fifth base electrode 13e.

[0076] The end surface electrode portion 141 of the second external electrode 14b is located on the second side surface 18b and the fourth side surface 18d and is connected to the ends of the multiple first internal electrodes 15a that are exposed on the second side surface 18b and the fourth side surface 18d. The principal surface electrode portion 142 of the second external electrode 14b is located on the first surface 17a and is connected to the second base electrode 13b. The principal surface electrode portion 142 of the second external electrode 14b may cover the second base electrode 13b. The principal surface electrode portion 142 of the second external electrode 14b may be located on the first surface 17a and the second surface 17b and is connected to the second base electrode 13b and the sixth base electrode 13f. The principal surface electrode portion 142 of the second external electrode 14b may cover the second base electrode 13b and the sixth base electrode 13f.

[0077] The end surface electrode portion 141 of the third external electrode 14c is located on the first side surface 18a and the fourth side surface 18d and is connected to the end portions of the plurality of second internal electrodes 15b that are exposed on the first side surface 18a and the fourth side surface 18d. The principal surface electrode portion 142 of the third external electrode 14c is located on the first surface 17a and is connected to the third base electrode 13c. The principal surface electrode portion 142 of the third external electrode 14c may cover the third base electrode 13c. The principal surface electrode portion 142 of the third external electrode 14c may be located on the first surface 17a and the second surface 17b and is connected to the third base electrode 13c and the seventh base electrode 13g. The principal surface electrode portion 142 of the third external electrode 14c may cover the third base electrode 13c and the seventh base electrode 13g.

[0078] The end surface electrode portion 141 of the fourth external electrode 14d is located on the second side surface 18b and the third side surface 18c and is connected to the ends of the multiple second internal electrodes 15b that are exposed on the second side surface 18b and the third side surface 18c. The principal surface electrode portion 142 of the fourth external electrode 14d is located on the first surface 17a and is connected to the fourth base electrode 13d. The principal surface electrode portion 142 of the fourth external electrode 14d may cover the fourth base electrode 13d. The principal surface electrode portion 142 of the fourth external electrode 14d may be located on the first surface 17a and the second surface 17b and may be connected to the fourth base electrode 13d and the eighth base electrode 13h. The principal surface electrode portion 142 of the first external electrode 14a may cover the fourth base electrode 13d and the eighth base electrode 13h.

[0079] The external electrodes 14 contain metal particles M. The multilayer ceramic capacitor 10A is configured such that the average particle size of the metal particles M contained in the end surface electrode portions 141 is smaller than the average particle size of the metal particles M contained in the main surface electrode portions 142. This provides the same effects as those of the first embodiment.

[0080] The average particle size of the metal particles M contained in the end surface electrode portion 141 may be, for example, 0.3 to 0.8 μm or 0.5 to 0.6 μm. The average particle size of the metal particles M contained in the main surface electrode portion 142 may be, for example, 0.3 to 1.3 μm or approximately 0.6 to 1.0 μm.

[0081] The base electrode 13 and the internal electrode 15 may be mainly composed of Ni, and the external electrode 14 may be mainly composed of Cu. In this case, the effects are the same as those of the first embodiment.

[0082] The average particle size of the metal particles M at a position P in the end surface electrode portion 141, which is a predetermined distance L1 away from the surface facing the laminate 12, may be smaller than the average particle size of the metal particles M at a position Q in the main surface electrode portion 142, which is a predetermined distance L1 away from the surface facing the laminate 12 (see FIGS. 5 and 6). The predetermined distance L1 may be, for example, 0.5 to 1.5 μm, or may be 1 μm. The effect in this case is the same as that of the first embodiment.

[0083] The average particle size of the metal particles M contained in the end surface electrode portion 141 may be 1.1 to 2.7 times the average particle size of the metal particles M contained in the main surface electrode portion 142. In this case, the effects are the same as those in the first embodiment.

[0084] The particle size of the metal particles M contained in the end surface electrode portion 141 may decrease toward the laminate 12. In this case, the effect is the same as in the first embodiment. Also, like in the first embodiment, it is not necessary for the particle sizes of all the metal particles M to strictly satisfy this relationship. For example, it is sufficient to measure the particle sizes of 3 or more, 10 or more, or 50 or more of the metal particles M contained in the end surface electrode portion 141, and have the relationship.

[0085] The particle diameters of the metal particles M contained in the principal surface electrode portion 142 may increase toward the laminate 12. In this case, the effect is the same as in the first embodiment. Similarly to the first embodiment, it is not necessary for the particle diameters of all the metal particles M to strictly satisfy this relationship. For example, it is sufficient to measure the particle diameters of 3 or more, 10 or more, or 50 or more of the metal particles M contained in the principal surface electrode portion 142, and have the relationship.

[0086] The multilayer ceramic capacitor 10A may be configured such that the average particle size of the metal particles contained in the base electrode 13 is larger than the average particle size of the metal particles contained in the internal electrode 15. In this case, the effects are the same as those of the first embodiment.

[0087] The multilayer ceramic capacitor 10A may be configured so that the average particle size of the metal particles at a position S in the base electrode 13, which is a predetermined distance L' away from the surface opposite the surface facing the laminate 12, is larger than the average particle size of the metal particles at a position R in the internal electrode 15, which is the predetermined distance L' away from the surface (side surfaces 18a-18d) of the laminate 12 (see FIGS. 5 and 6). The predetermined distance L' may be, for example, 0.5 to 1.5 μm, or 1 μm. The effect in this case is the same as that of the first embodiment.

[0088] The following describes a method for manufacturing the multilayer ceramic capacitor 10. The method for manufacturing the multilayer ceramic capacitor 10 includes a first step of producing a base laminate, a second step of producing an element component, and a third step of forming external electrodes.

[0089] Fig. 13 is a perspective view illustrating an example of a process for producing a base laminate, Fig. 14 is a perspective view showing an example of a base laminate, and Fig. 15 is a perspective view showing an element component precursor obtained by cutting the base laminate of Fig. 14. In Figs. 13 to 15, for ease of illustration, the internal electrode patterns, base electrode patterns, ends of the internal electrode patterns exposed on the surface of the base laminate, and ends of the internal electrode patterns exposed on the surface of the element component are hatched.

[0090] (1st step) The first step is to prepare a base laminate for forming the element component precursor. In the first step, a raw material powder containing BaTiO3 as a main component is first prepared. Next, an organic vehicle is mixed with the prepared raw material powder to prepare a ceramic slurry. The organic vehicle used to prepare the ceramic slurry may be, for example, a butyral resin or other resin dissolved in a solvent mixture of ethyl alcohol and toluene. Next, the prepared ceramic slurry is used to form a ceramic green sheet 21, which will become the dielectric layer 6, on a carrier film by a sheet forming method such as a die coater method, a doctor blade method, or a gravure coater method.

[0091] Next, an organic vehicle is mixed with the Ni-based powder to prepare a conductive paste. The organic vehicle used to prepare the conductive paste may be, for example, a resin such as ethyl cellulose dissolved in a solvent mixture of a dihydroterpineol-based solvent and butyl cellosolve. A dispersant such as oleic acid or polyethylene glycol may be added to the conductive paste.

[0092] Next, using the prepared conductive paste, a ceramic green sheet 21 on which an internal electrode pattern that will become the internal electrode 5 is printed and a ceramic green sheet 21 on which a base electrode pattern that will become the base electrode 3 is printed are produced. The internal electrode pattern and the base electrode pattern can be printed by a printing method such as screen printing or gravure printing. Hereinafter, the ceramic green sheet 21 on which the internal electrode pattern is printed may be referred to as an internal electrode sheet 22, and the ceramic green sheet 21 on which the base electrode pattern is printed may be referred to as a base electrode sheet 23.

[0093] Next, as shown in FIG. 13 , a predetermined number of internal electrode sheets 22 are stacked on a base electrode sheet 23, and further base electrode sheets 23 are stacked to produce a temporary laminate. When producing the temporary laminate, the predetermined number of internal electrode sheets 22 may be stacked while being shifted by half the width dimension of the internal electrode pattern along the width direction (x-axis direction). In this case, the first internal electrode 5a and the second internal electrode 5b can be formed using internal electrode sheets 22 on which the same internal electrode pattern is printed. In addition, one or more ceramic green sheets 21 may be disposed between the base electrode sheet 23 and the internal electrode sheet 22. In this case, the risk of short-circuiting between internal electrodes 5 of different polarities can be reduced.

[0094] Next, the temporary laminate is pressed in the stacking direction to produce a mother laminate 24 as shown in Fig. 14. The temporary laminate can be pressed using, for example, an isostatic press. The temporary laminate and the mother laminate 24 may be produced on a support sheet (reference numeral omitted) as shown in Figs. 13 and 14.

[0095] (2nd process) The second step is to produce the element components 1. First, the base laminate 24 is cut along the grid-like planned cutting lines 25 to produce a plurality of precursors of the element components 1 (hereinafter also referred to as element component precursors 1p) as shown in FIG. 15. The base laminate 24 can be cut using, for example, a press cutter or a dicing saw. Note that the element component precursors 1p have substantially the same structure as the element components 1, and therefore, in the following description, terms and reference numerals such as first surface 7a, first end surface 8a, base electrode 3, and internal electrode 5 may also be used for the element component precursors 1p.

[0096] Next, the element component precursor 1p is fired. The firing temperature may be set appropriately depending on the ceramic material contained in the ceramic green sheets, the metal material contained in the conductive paste, etc., but may be, for example, about 1100 to 1250°C. The element component precursor 1p may be subjected to a degreasing treatment before firing. The degreasing treatment may be performed in an air atmosphere, an inert gas atmosphere, or a reducing atmosphere. The degreasing treatment may be performed under atmospheric pressure or under reduced pressure. Furthermore, the element component precursor 1p after firing may be subjected to a reoxidation treatment.

[0097] Next, the element component precursor 1p is placed in a rotary pot containing an abrasive and barrel polished to remove burrs from the surface of the element component precursor 1p, round off the corners, and fully expose the ends of the internal electrodes 5 on the end faces 8a and 8b of the laminate 2. In this way, the element component 1 as shown in FIG.

[0098] (3rd step) The third step is a step of forming external electrodes 4 on the element component 1. First, plating layers that will become the external electrodes 4 are formed on the element component 1 using a plating method such as electroless plating or electrolytic plating to produce a precursor of the multilayer ceramic capacitor 10 (hereinafter also referred to as a capacitor precursor). The plating layers include a first plating layer that will become the first external electrode 4a and a second plating layer that will become the second external electrode 4b. In the third step, the first plating layer is formed so as to extend from the first end face 8a to the first surface 7a, the second surface 7b, the first side surface 9a, and the second side surface 9b, and to connect to the multiple first internal electrodes 5a, the first base electrode 3a, and the third base electrode 3c. The second plating layer is formed so as to extend from the second end face 8b to the first surface 7a, the second surface 7b, the first side surface 9a, and the second side surface 9b, and to connect to the multiple second internal electrodes 5b, the second base electrode 3b, and the fourth base electrode 3d. When forming the plating layers, the first plating layer may be formed so as to completely cover the first base electrode 3 a and the third base electrode 3 c, and the second plating layer may be formed so as to completely cover the second base electrode 3 b and the fourth base electrode 3 d. Furthermore, the first plating layer and the second plating layer may be composed of a single plating layer mainly composed of Cu (see FIG. 3), or may be composed of a plating layer mainly composed of Cu and one or more plating layers mainly composed of Ni, Sn, etc. (see FIG. 4).

[0099] Next, the capacitor precursor is annealed to grow metal particles contained in the portion of the plating layer located on the principal surfaces 7a, 7b and connected to the base electrode 3 (hereinafter, for convenience, also referred to as the principal surface electrode portion 42). During the annealing, heat is transferred more easily to the principal surface electrode portion 42 than to the portion of the plating layer located on the end surfaces 8a, 8b and connected to the internal electrode 5 (hereinafter, for convenience, also referred to as the end surface electrode portion 41). This makes it possible to suppress the grain growth of metal particles in the end surface electrode portion 41 while promoting the grain growth of metal particles in the principal surface electrode portion 42. As a result, an external electrode 4 can be formed in which the average grain size of the metal particles contained in the principal surface electrode portion 42 is larger than the average grain size of the metal particles contained in the end surface electrode portion 41.

[0100] The annealing conditions may be, for example, a temperature rise rate of 5 to 10°C / min, a treatment temperature of 500 to 800°C, and a temperature holding time of 0.5 to 3 hours. To promote grain growth of metal particles in the principal-surface electrode portion 42 while suppressing grain growth of metal particles in the end-surface electrode portion 41, the capacitor precursor may be positioned in an annealing furnace so that heat is transferred more efficiently to the principal-surface electrode portion 42 than to the end-surface electrode portion 41. Alternatively, the annealing may be performed while pressurizing the capacitor precursor in the stacking direction. This promotes grain growth of metal particles in the pressed principal-surface electrode portion 42, thereby making the grain size of the metal particles in the principal-surface electrode portion 42 larger than that of the metal particles in the end-surface electrode portion 41. To pressurize the capacitor precursor in the stacking direction, for example, a pair of substrates or a pair of sheets may be positioned so that the capacitor precursor is sandwiched between them in the stacking direction, and the capacitor precursor may be pressed in the stacking direction via the pair of substrates or the pair of sheets. Alternatively, the annealing may be performed while multiple capacitor precursors are stacked in the stacking direction.

[0101] Any method can be used to increase the particle size of the metal particles M contained in the principal-surface electrode portion 42 toward the laminate 2. For example, as already mentioned, the material of the external electrode 4 may be Cu, the material of the base electrode 3 may be Ni, and annealing may be performed to alloy Cu and Ni at the interface between them and cause grain growth. In this case, since the end-surface electrode portion 41 only partially contacts the internal electrode 5, even if the internal electrode 5 is made of Ni, the particle size may increase only in the principal-surface electrode portion 42 toward the laminate 2. Furthermore, when the external electrode 4 is formed using two or more plating layers, the type and conditions of the plating method may be changed so that the particle size increases in the layers closer to the laminate 2. In this case, at least a portion of the plating layer formation process may be performed separately for the end-surface electrode portion 41 and the principal-surface electrode portion 42, thereby increasing the particle size only in the principal-surface electrode portion 42 toward the laminate 2.

[0102] Any method can be used to decrease the particle size of the metal particles M contained in the end surface electrode portion 41 as it approaches the laminate 2. For example, the temperature of the outer surface of the end surface electrode portion 41 may be made higher than the temperature of the inner surface during annealing, thereby promoting grain growth on the outer surface side more than on the inner surface side. And / or, when forming the external electrode 4 (at least the end surface electrode portion 41) using two or more plating layers, the type and conditions of the plating method may be changed so that the particle size decreases in the layers closer to the laminate 2.

[0103] Any method can be used to make the average particle size of the metal particles contained in the base electrode 3 larger than the average particle size of the metal particles contained in the internal electrode 5. For example, similar to the external electrode 4, heating may be performed so that the grain growth of the base electrode 3 is promoted more than the grain growth of the internal electrode 5. And / or the grain size of the metal particles contained in the conductive paste that will become the base electrode 3 may be made larger than the grain size of the metal particles contained in the conductive paste that will become the internal electrode 5.

[0104] In this manner, the multilayer ceramic capacitor 10 of the first embodiment can be manufactured. The multilayer ceramic capacitor 10A of the second embodiment can be manufactured by the same manufacturing method as the multilayer ceramic capacitor 10.

[0105] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible within the scope that does not deviate from the gist of the present disclosure.

[0106] The multilayer electronic component of the present disclosure may be, for example, the multilayer ceramic capacitor of the third embodiment shown in Figures 16 to 19, or the multilayer ceramic capacitor of the fourth embodiment shown in Figures 20 to 23. The multilayer ceramic capacitors of the third and fourth embodiments will be described below.

[0107] Fig. 16 is a perspective view showing a multilayer ceramic capacitor of a third embodiment, Fig. 17 is a perspective view showing an element component of the multilayer ceramic capacitor of Fig. 16, Fig. 18 is a view showing an example of a cross section taken along the section line XVIII-XVIII of Fig. 16, and Fig. 19 is a view showing an example of a cross section taken along the section line XIX-XIX of Fig. 16. Fig. 20 is a perspective view showing a multilayer ceramic capacitor of a fourth embodiment, Fig. 21 is a perspective view showing an element component of the multilayer ceramic capacitor of Fig. 20, Fig. 22 is a view showing an example of a cross section taken along the section line XXII-XXII of Fig. 20, and Fig. 23 is a view showing an example of a cross section taken along the section line XXIII-XXIII of Fig. 20.

[0108] As shown in Fig. 16, the multilayer ceramic capacitor 10B of the third embodiment includes an element component 26 and a plurality of external electrodes 29. As shown in Fig. 17, the element component 26 includes a laminate 27 and a plurality of base electrodes 28. The multilayer ceramic capacitor 10B may be a thin multilayer ceramic capacitor in which the dimension T in the height direction (z-axis direction) is smaller than the dimension L in the length direction (x-axis direction) and the dimension W in the width direction (y-axis direction).

[0109] The laminate 27 is formed by alternately stacking a plurality of internal electrodes 30 and a plurality of dielectric layers 31. The laminate 27 may have a substantially rectangular parallelepiped shape. The laminate 27 has a first surface 32a and a second surface 32b facing each other in the stacking direction, a first end surface 33a and a second end surface 33b facing each other in the length direction, and a first side surface 34a and a second side surface 34b facing each other in the width direction.

[0110] The dielectric layer 31 is made of a ceramic material whose main component is, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, or CaZrO3. The ceramic material may contain a secondary component such as a Mn compound, an Mg compound, an Si compound, a Co compound, an Ni compound, or a rare earth compound. The dielectric layer 31 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0111] As shown in Figures 17 to 19, the multiple internal electrodes 30 include multiple first internal electrodes 30a and multiple second internal electrodes 30b. The first internal electrodes 30a have ends exposed at a first end face 33a and a second end face 33b. The second internal electrodes 30b have ends exposed at a first side face 34a and a second side face 34b. The first internal electrodes 30a and the second internal electrodes 30b have mutually opposite polarities.

[0112] The internal electrode 30 is made of a metal material containing, for example, Ni, Cu, Sn, etc. as a main component. The internal electrode 15 may contain a ceramic material such as BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The internal electrode 30 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0113] As shown in Figures 18 and 19, the laminate 27 may include a capacitance-forming portion 27a and cover portions 27b and 27c. The capacitance-forming portion 27a is formed by alternately stacking a plurality of internal electrodes 30 and a plurality of dielectric layers 31, and forms a capacitance. The cover portions 27b and 27c are located at both ends of the capacitance-forming portion 27a in the stacking direction. The cover portions 27b and 27c are made of one or more dielectric layers and do not necessarily form a capacitance.

[0114] The cover portions 27b and 27c (their dielectric layers) are made of a ceramic material whose main component is, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The cover portions 27b and 27c may be made of the same ceramic material as the ceramic material that makes up the dielectric layer 31.

[0115] The multiple base electrodes 28 include a first base electrode 28a, a second base electrode 28b, a third base electrode 28c, and a fourth base electrode 28d. The first base electrode 28a is located on the first surface 32a closer to the first end face 33a, and the second base electrode 28b is located on the first surface 32a closer to the second end face 33b. The third base electrode 28c is located on the first surface 32a closer to the first side face 34a, and the fourth base electrode 28d is located on the first surface 32a closer to the second side face 34b. The third base electrode 28c and the fourth base electrode 28d may be located in the center of the first surface 32a in the longitudinal direction. The third base electrode 28c and the fourth base electrode 28d may have, for example, a substantially semicircular, rectangular, or triangular shape in a plan view.

[0116] The base electrodes 28 may include a fifth base electrode 28e, a sixth base electrode 28f, a seventh base electrode 28g, and an eighth base electrode 28h. The fifth base electrode 28e is located closer to the first end face 33a on the second surface 32b, and the sixth base electrode 28f is located closer to the second end face 33b on the second surface 32b. The seventh base electrode 28g is located closer to the first side face 34a on the second surface 32b, and the eighth base electrode 28h is located closer to the second side face 34b on the second surface 32b. The fifth base electrode 28e to the eighth base electrode 28h may have the same configuration as the first base electrode 28a to the fourth base electrode 28d, respectively, except that they are located on the second surface 32b.

[0117] As shown in FIG. 16, the plurality of external electrodes 29 include a first external electrode 29a, a second external electrode 29b, a third external electrode 29c, and a fourth external electrode 29d.

[0118] The first external electrode 29a is located from the first end face 33a across at least the first surface 32a and is connected to the plurality of first internal electrodes 30a and the first base electrode 28a. The first external electrode 29a may cover the first base electrode 28a. The first external electrode 29a is located from the first end face 33a across the first surface 32a and the second surface 32b and may be connected to the plurality of first internal electrodes 30a, the first base electrode 28a, and the fifth base electrode 28e. The first external electrode 29a may cover the first base electrode 28a and the fifth base electrode 28e. The first external electrode 29a may be located from the first end face 33a across the first surface 32a, the second surface 32b, the first side surface 34a, and the second side surface 34b.

[0119] The second external electrode 29b is located from the second end face 33b across at least the first surface 32a and is connected to the plurality of second internal electrodes 30b and the second base electrode 28b. The second external electrode 29b may cover the second base electrode 28b. The second external electrode 29b is located from the second end face 33b across the first surface 32a and the second surface 32b and is connected to the plurality of second internal electrodes 30b, the second base electrode 28b, and the sixth base electrode 28f. The second external electrode 29b may cover the second base electrode 28b and the sixth base electrode 28f. The second external electrode 29b may be located from the second end face 33b across the first surface 32a, the second surface 32b, the first side surface 34a, and the second side surface 34b.

[0120] The third external electrode 29c is located from the first side surface 34a to at least the first surface 32a, and is connected to the plurality of second internal electrodes 30b and the third base electrode 28c. The third external electrode 29c may cover the third base electrode 28c. The third external electrode 29c is located from the first side surface 34a to the first surface 32a and the second surface 32b, and may be connected to the plurality of second internal electrodes 30b, the third base electrode 28c, and the seventh base electrode 28g. The third external electrode 29c may cover the third base electrode 28c and the seventh base electrode 28g.

[0121] The fourth external electrode 29d is located from the second side surface 34b across at least the first surface 32a, and is connected to the plurality of second internal electrodes 30b and the fourth base electrode 28d. The fourth external electrode 29d may cover the fourth base electrode 28d. The fourth external electrode 29d is located from the second side surface 34b across the first surface 32a and the second surface 32b, and may be connected to the plurality of second internal electrodes 30b, the fourth base electrode 28d, and the eighth base electrode 28h. The fourth external electrode 29d may cover the fourth base electrode 28d and the eighth base electrode 28h.

[0122] The external electrode 29 may be a plating layer formed directly on the laminate 27 by plating. The external electrode 29 may be composed of two or more plating layers. The external electrode 29 may be composed of a first layer connected to the base electrode 28 and the internal electrode 30, and a second layer covering the first layer. The external electrode 29 may be composed of a first layer connected to the base electrode 28 and the internal electrode 30, a second layer covering the first layer, and a third layer covering the second layer. In this case, the first layer may be formed by direct plating.

[0123] The first external electrode 29a to the fourth external electrode 29d each have a first portion 291 and a second portion 292. The first portion 291 is located on the first end surface 33a, the second end surface 33b, the first side surface 34a, or the second side surface 34b of the laminate 27 and is connected to the plurality of first internal electrodes 30a or the plurality of second internal electrodes 30b. The second portion 292 is located on the first surface 32a or the second surface 32b of the laminate 27 and is connected to any of the first to fourth base electrodes 28a to 28d. The second portion 292 may cover any of the first to fourth base electrodes 28a to 28d. The second portion 292 may also be located on the second surface 32b and be connected to any of the fifth to eighth base electrodes 28e to 28h. The second portion 292 may cover any of the fifth to eighth base electrodes 28e to 28h. The first portion 291 is also referred to as an end surface electrode portion, and the second portion 292 is also referred to as a main surface electrode portion.

[0124] Next, a description will be given of the multilayer ceramic capacitor according to the fourth embodiment. In the following description, the same terms and reference numerals will be used for the same configurations as those of the multilayer ceramic capacitor according to the third embodiment, and detailed description will be omitted.

[0125] As shown in Fig. 20, the multilayer ceramic capacitor 10C of the fourth embodiment includes an element component 26 and a plurality of external electrodes 29. As shown in Fig. 21, the element component 26 includes a laminate 27 and a plurality of base electrodes 28. The multilayer ceramic capacitor 10C may be a thin multilayer ceramic capacitor in which the dimension T in the height direction (z-axis direction) is smaller than the dimension L in the length direction (x-axis direction) and the dimension W in the width direction (y-axis direction).

[0126] 21 to 23, the laminate 27 is formed by alternately stacking a plurality of internal electrodes 30 and a plurality of dielectric layers 31. The laminate 27 may have a substantially rectangular parallelepiped shape. The laminate 27 has a first surface 32a and a second surface 32b facing each other in the stacking direction, a first end surface 33a and a second end surface 33b facing each other in the length direction, and a first side surface 34a and a second side surface 34b facing each other in the width direction.

[0127] As shown in FIGS. 21 to 23, the plurality of internal electrodes 30 includes a plurality of first internal electrodes 30a and a plurality of second internal electrodes 30b.

[0128] The first internal electrode 30a has a plurality of ends exposed on the first side surface 34a and a plurality of ends exposed on the second side surface 34b. The second internal electrode 30b has a plurality of ends exposed on the first side surface 34a and a plurality of ends exposed on the second side surface 34b. On the first side surface 34a, the positions of the plurality of exposed portions of the first internal electrode 30a and the plurality of exposed portions of the second internal electrode 30b are different from each other in the longitudinal direction. On the second side surface 34b, the positions of the plurality of exposed portions of the first internal electrode 30a and the plurality of exposed portions of the second internal electrode 30b are different from each other in the longitudinal direction. The first internal electrode 30a and the second internal electrode 30b have opposite polarities.

[0129] As shown in Figures 22 and 23, the laminate 27 may include a capacitance-forming portion 27a and cover portions 27b and 27c. The capacitance-forming portion 27a is formed by alternately stacking a plurality of internal electrodes 30 and a plurality of dielectric layers 31, and forms a capacitance. The cover portions 27b and 27c are located at both ends of the capacitance-forming portion 27a in the stacking direction. The cover portions 27b and 27c are made of one or more dielectric layers and do not necessarily form a capacitance.

[0130] The multiple base electrodes 28 include a first base electrode 28a, a second base electrode 28b, a third base electrode 28c, a fourth base electrode 28d, a fifth base electrode 28e, a sixth base electrode 28f, a seventh base electrode 28g, and an eighth base electrode 28h. The first base electrode 28a to the fourth base electrode 28d are located closer to the first side surface 34a on the first surface 32a. The fifth base electrode 28e to the eighth base electrode 28h are located closer to the second side surface 34b on the first surface 32a.

[0131] The base electrodes 28 may include ninth to sixteenth base electrodes. The ninth to twelfth base electrodes are located closer to the first side surface 34a on the second surface 32b. The thirteenth to sixteenth base electrodes are located closer to the second side surface 34b on the second surface 32b. The ninth to twelfth base electrodes may have the same configuration as the first to fourth base electrodes 28a to 28d, respectively, except that they are located on the second surface 32b. The thirteenth to sixteenth base electrodes may have the same configuration as the fifth to eighth base electrodes 28e to 28h, respectively, except that they are located on the second surface 32b.

[0132] As shown in FIG. 20, the multiple external electrodes 29 include a first external electrode 29a, a second external electrode 29b, a third external electrode 29c, a fourth external electrode 29d, a fifth external electrode 29e, a sixth external electrode 29f, a seventh external electrode 29g, and an eighth external electrode 29h.

[0133] The first external electrode 29a and the third external electrode 29c are located from the first side surface 34a to at least the first surface 32a and are connected to the plurality of second internal electrodes 30b. The first external electrode 29a and the third external electrode 29c are connected to the first underlying electrode 28a and the third underlying electrode 28c, respectively. The first external electrode 29a and the third external electrode 29c may cover the first underlying electrode 28a and the third underlying electrode 28c, respectively. The first external electrode 29a is located from the first side surface 34a to the first surface 32a and the second surface 32b and may be connected to the first underlying electrode 28a and the ninth underlying electrode. The first external electrode 29a may cover the first underlying electrode 28a and the ninth underlying electrode. The third external electrode 29c may be located from the first side surface 34a across the first surface 32a and the second surface 32b, and may be connected to the third underlying electrode 28c and the eleventh underlying electrode. The third external electrode 29c may cover the third underlying electrode 28c and the eleventh underlying electrode.

[0134] The second external electrode 29b and the fourth external electrode 29d are located from the first side surface 34a to at least the first surface 32a and are connected to the plurality of first internal electrodes 30a. The second external electrode 29b and the fourth external electrode 29d are connected to the second underlying electrode 28b and the fourth underlying electrode 28d, respectively. The second external electrode 29b and the fourth external electrode 29d may cover the second underlying electrode 28b and the fourth underlying electrode 28d, respectively. The second external electrode 29b is located from the first side surface 34a to the first surface 32a and the second surface 32b and may be connected to the second underlying electrode 28b and the tenth underlying electrode. The second external electrode 29b may cover the second underlying electrode 28b and the tenth underlying electrode. The fourth external electrode 29d may be located from the first side surface 34a across the first surface 32a and the second surface 32b, and may be connected to the fourth underlying electrode 28d and the twelfth underlying electrode. The fourth external electrode 29d may cover the fourth underlying electrode 28d and the twelfth underlying electrode.

[0135] The sixth external electrode 29f and the eighth external electrode 29h are located from the second side surface 34b across at least the first surface 32a and are connected to the plurality of second internal electrodes 30b. The sixth external electrode 29f and the eighth external electrode 29h are connected to the sixth underlying electrode 28f and the eighth underlying electrode 28h, respectively. The sixth external electrode 29f and the eighth external electrode 29h may cover the sixth underlying electrode 28f and the eighth underlying electrode 28h, respectively. The sixth external electrode 29f is located from the second side surface 34b across the first surface 32a and the second surface 32b and may be connected to the sixth underlying electrode 28f and the fourteenth underlying electrode. The sixth external electrode 29f may cover the sixth underlying electrode 28f and the fourteenth underlying electrode. The eighth external electrode 29h may be located from the second side surface 34b across the first surface 32a and the second surface 32b, and may be connected to the eighth underlying electrode 28h and the sixteenth underlying electrode. The eighth external electrode 29h may cover the eighth underlying electrode 28h and the sixteenth underlying electrode.

[0136] The fifth external electrode 29e and the seventh external electrode 29g are located from the second side surface 34b to at least the first surface 32a and are connected to the plurality of first internal electrodes 30a. The fifth external electrode 29e and the seventh external electrode 29g are connected to the fifth underlying electrode 28e and the seventh underlying electrode 28g, respectively. The fifth external electrode 29e and the seventh external electrode 29g may cover the fifth underlying electrode 28e and the seventh underlying electrode 28g, respectively. The fifth external electrode 29e is located from the second side surface 34b to the first surface 32a and the second surface 32b and may be connected to the fifth underlying electrode 28e and the thirteenth underlying electrode. The fifth external electrode 29e may cover the fifth underlying electrode 28e and the thirteenth underlying electrode. The seventh external electrode 29g may be located from the second side surface 34b across the first surface 32a and the second surface 32b, and may be connected to the seventh underlying electrode 28g and the fifteenth underlying electrode. The seventh external electrode 29g may cover the seventh underlying electrode 28g and the fifteenth underlying electrode.

[0137] The first external electrode 29a to the eighth external electrode 29h each have a first portion 291 and a second portion 292. The first portion 291 is located on the first side surface 34a or the second side surface 34b and is connected to the plurality of first internal electrodes 30a or the plurality of second internal electrodes 30b. The second portion 292 is located on the first surface 32a and is connected to one of the first to eighth base electrodes 28a to 28h. The second portion 292 may cover one of the first to eighth base electrodes 28a to 28h. The second portion 292 is also located on the second surface 32b and may be connected to one of the ninth to sixteenth base electrodes. The second portion 292 may cover one of the ninth to sixteenth base electrodes. The first portion 291 is also referred to as an end surface electrode portion, and the second portion 292 is also referred to as a main surface electrode portion.

[0138] The configurations of the end surface electrode portions 291 and main surface electrode portions 292 of the multilayer ceramic capacitors 10B and 10C will be described below. The explanation regarding the configurations of the end surface electrode portions 41 and main surface electrode portions 42 of the multilayer ceramic capacitor 10 may be applied to the multilayer ceramic capacitors 10B and 10C unless a contradiction arises. Just to be sure, a brief explanation will be given below.

[0139] The external electrode 29 contains metal particles M. The multilayer ceramic capacitors 10B and 10C are configured such that the average particle size of the metal particles M contained in the end surface electrode portions 291 is smaller than the average particle size of the metal particles M contained in the main surface electrode portions 292.

[0140] The average particle size of the metal particles M contained in the end surface electrode portion 291 may be, for example, 0.3 to 0.8 μm or 0.5 to 0.6 μm. The average particle size of the metal particles M contained in the main surface electrode portion 292 may be, for example, 0.3 to 1.3 μm or approximately 0.6 to 1.0 μm.

[0141] The base electrode 28 and the internal electrodes 30 may be mainly composed of Ni, and the external electrode 29 may be mainly composed of Cu.

[0142] The average particle size of the metal particles M at a position P in the end surface electrode portion 291 that is a predetermined distance L1 away from the surface facing the laminate 27 may be smaller than the average particle size of the metal particles M at a position Q in the main surface electrode portion 292 that is a predetermined distance L1 away from the surface facing the laminate 27 (see FIGS. 5 and 6). The predetermined distance L1 may be, for example, 0.5 to 1.5 μm, or 1 μm.

[0143] The average particle size of the metal particles M contained in the end surface electrode portion 291 may be 1.1 to 2.7 times the average particle size of the metal particles M contained in the main surface electrode portion 292.

[0144] The particle size of the metal particles M contained in the end surface electrode portion 291 may decrease as it approaches the laminate 27.

[0145] The particle size of the metal particles M contained in the principal surface electrode portion 292 may increase toward the laminate 27.

[0146] The multilayer ceramic capacitors 10B and 10C may be configured such that the average particle size of the metal particles contained in the base electrode 28 is larger than the average particle size of the metal particles contained in the internal electrode 30.

[0147] The multilayer ceramic capacitors 10B and 10C may be configured so that the average particle size of the metal particles at a position S in the base electrode 28 that is a predetermined distance L' away from the surface opposite the surface on the laminate 27 side is larger than the average particle size of the metal particles at a position R in the internal electrode 30 that is the predetermined distance L' away from the surface of the laminate 27 (see FIGS. 5 and 6). The predetermined distance L' may be, for example, 0.5 to 1.5 μm, or 1 μm.

[0148] Although not specifically shown, further embodiments will be described. For convenience, the following description may use the reference numerals of any of the first to fourth embodiments. The following description may be applied to embodiments other than the embodiment to which the reference numerals refer, unless a contradiction arises.

[0149] The base electrode 13 may be embedded in the laminate 12 (more specifically, the cover portions 12b and 12c) with the upper or lower surface exposed to the outside of the laminate 12. In other words, the base electrode 13 may be recessed with respect to the cover portions 12b and 12c. From another perspective, the first surface 17a and the second surface 17b of the laminate 12 do not have to be flat, and may be recessed at the position of the base electrode 13. For convenience, attention will be focused on the base electrode 13 on the upper surface side of the laminate 12. The upper surface of the embedded base electrode 13 may be flush with or located above the region of the first surface 17a where the base electrode 13 is not disposed.

[0150] As described above, even when the base electrode 13 is embedded, the base electrode 13 is still located on the first surface 17a or the second surface 17b. In other words, in the laminate 12, the bottom surface of the recess in which the base electrode 13 is disposed is part of the first surface 17a or the second surface 17b.

[0151] The method for fabricating the embedded base electrode 13 as described above is arbitrary. For example, taking the top surface side as an example, the cover portion 12b is fabricated using two layers of ceramic green sheets. A precursor for the base electrode 13 is printed on the ceramic green sheet for the lower layer. A notch where the base electrode 13 is to be located is formed in the ceramic green sheet for the upper layer. This results in the fabrication of the embedded base electrode 13. And / or, the precursor for the base electrode 13 may be pressed into the ceramic green sheets.

[0152] The capacitor may have an exterior resin that covers the entire structure illustrated in Fig. 1 etc., and lead wires that are connected to the external electrodes and extend from the exterior resin. From another perspective, the capacitor may be a through-hole mount type rather than a surface mount type.

[0153] Two types of internal electrodes connected to different external electrodes may be alternately stacked two by two, rather than one by one. In this case, for example, the thickness of the dielectric layer between the internal electrodes connected to the same external electrode and facing each other may be thinner than the thickness of the dielectric layer between the internal electrodes connected to different external electrodes and facing each other. As can be understood from this, the multiple dielectric layers do not need to have the same shape and size.

[0154] Furthermore, two types of internal electrodes connected to different external electrodes do not have to face each other. For example, two types of internal electrodes connected to different external electrodes may be provided on the same layer, and an internal electrode facing the two types of internal electrodes may be provided, thereby forming a circuit in which two parallel plate capacitors are connected in series. Also, a circuit in which three or more parallel plate capacitors are connected in series may be formed.

[0155] In the first embodiment, the internal electrodes 5 are contained within the width (y direction) of the dielectric layers 6, and therefore are not exposed from the side surfaces 9a, 9b of the laminate 2. However, a configuration in which the internal electrodes 5 are not exposed may be achieved by overlapping dielectric layers on the side surfaces 9a, 9b. From another perspective, the entire element part 1 does not need to have a laminated structure.

[0156] The present disclosure can be implemented in the following aspects (1) to (11).

[0157] (1) A laminate formed by alternately stacking a plurality of internal electrodes and a plurality of dielectric layers, the laminate having a first surface and a second surface opposing each other in a stacking direction, a first end surface and a second end surface opposing each other in a length direction perpendicular to the stacking direction, and a first side surface and a second side surface opposing each other in a width direction perpendicular to the stacking direction and the length direction; A plurality of base electrodes; a plurality of external electrodes; the plurality of internal electrodes include a plurality of first internal electrodes exposed at the first end surface and a plurality of second internal electrodes exposed at the second end surface, the plurality of base electrodes include a first base electrode located on the first surface closer to the first end face and a second base electrode located on the first surface closer to the second end face, The plurality of external electrodes are a first external electrode located from the first end surface across at least the first surface and connected to the plurality of first internal electrodes and the first base electrode; a second external electrode located from the second end surface to at least the first surface and connected to the plurality of second internal electrodes and the second base electrode; each of the first external electrode and the second external electrode has a first portion connected to the plurality of first internal electrodes or the plurality of second internal electrodes, and a second portion connected to either the first base electrode or the second base electrode; The multilayer electronic component has a smaller average particle size of the metal particles contained in the first portion than the average particle size of the metal particles contained in the second portion.

[0158] (2) A laminate formed by alternately stacking a plurality of internal electrodes and a plurality of dielectric layers, the laminate having a first surface and a second surface facing each other in a stacking direction, a first side surface and a second side surface facing each other in a length direction perpendicular to the stacking direction, and a third side surface and a fourth side surface facing each other in a width direction perpendicular to the stacking direction and the length direction; A plurality of base electrodes; a plurality of external electrodes; The plurality of internal electrodes are a plurality of first internal electrodes exposed at a first corner portion extending from the first side surface to the third side surface and at a second corner portion extending from the second side surface to the fourth side surface; a plurality of second internal electrodes exposed at a third corner portion extending from the first side surface to the fourth side surface and at a fourth corner portion extending from the second side surface to the third side surface, The plurality of base electrodes are a first base electrode located near the first corner on the first surface; a second base electrode located near the second corner on the first surface; a third base electrode located on the first surface near the third corner portion; a fourth base electrode located near the fourth corner portion on the first surface, The plurality of external electrodes are a first external electrode located from the first corner portion across at least the first surface and connected to the plurality of first internal electrodes and the first base electrode; a second external electrode located from the second corner portion across at least the first surface and connected to the plurality of first internal electrodes and the second base electrode; a third external electrode located from the third corner portion across at least the first surface and connected to the plurality of second internal electrodes and the third base electrode; a fourth external electrode located from the fourth corner portion across at least the first surface and connected to the plurality of second internal electrodes and the fourth base electrode, each of the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode has a first portion connected to the plurality of first internal electrodes or the plurality of second internal electrodes, and a second portion connected to any of the first base electrode, the second base electrode, the third base electrode, and the fourth base electrode; The multilayer electronic component has a smaller average particle size of the metal particles contained in the first portion than the average particle size of the metal particles contained in the second portion.

[0159] (3) The multilayer electronic component according to (1) or (2) above, wherein the plurality of external electrodes are plated layers.

[0160] (4) The multilayer electronic component according to any one of (1) to (3) above, wherein the plurality of internal electrodes are mainly composed of Ni, and the plurality of external electrodes are mainly composed of Cu.

[0161] (5) The multilayer electronic component according to any one of (1) to (4), wherein the average particle size of the metal particles in the first portion at a position spaced a predetermined distance in the longitudinal direction from the surface of the laminate side is smaller than the average particle size of the metal particles in the second portion at a position spaced a predetermined distance in the stacking direction from the surface of the laminate side.

[0162] (6) The multilayer electronic component according to any one of (1) to (5) above, wherein the average particle size of the metal particles contained in the second portion is 1.1 to 2.7 times the average particle size of the metal particles contained in the first portion.

[0163] (7) The multilayer electronic component according to any one of (1) to (6) above, wherein the particle size of the metal particles contained in the first portion decreases toward the laminate.

[0164] (8) The multilayer electronic component according to any one of (1) to (7) above, wherein the particle size of the metal particles contained in the second portion increases toward the laminate.

[0165] (9) The multilayer electronic component according to any one of (1) to (8) above, wherein the average particle size of the metal particles contained in the plurality of base electrodes is larger than the average particle size of the metal particles contained in the plurality of internal electrodes.

[0166] (10) A multilayer electronic component according to any one of (1) to (9), wherein the average particle size of the metal particles in the plurality of base electrodes at a position spaced a predetermined distance in the stacking direction from a surface opposite to the surface on the laminate side is larger than the average particle size of the metal particles in the plurality of internal electrodes at a position spaced a predetermined distance in the length direction from a surface of the laminate.

[0167] (11) The multilayer electronic component according to any one of (1) to (10) above, wherein the dimension in the stacking direction is smaller than the dimension in the length direction and smaller than the dimension in the width direction. [Explanation of symbols]

[0168] 10, 10A, 10B, 10C... multilayer electronic component (multilayer ceramic capacitor), 1... element component, 1p... element component precursor, 2... laminate, 2a... capacitance forming portion, 2b, 2c... cover portion, 3... base electrode, 3a... first base electrode, 3b... second base electrode, 3c... third base electrode, 3d... fourth base electrode, 4... external electrode, 4a... first external electrode, 4b... second external electrode, 4aa... first layer, 4ab... second layer, 41... first part minute (end surface electrode part), 42... second part (principal surface electrode part), 5... internal electrode, 5a... first internal electrode, 5b... second internal electrode, 6... dielectric layer, 7a... first surface, 7b... second surface, 8a... first end surface, 8b... second end surface, 9a...first side surface, 9b...second side surface, 11...element body parts, 12...laminate, 12a...capacitance forming part, 12b, 12c...cover part, 13...base electrode, 13a...first base electrode, 13b...second base electrode, 13c...th 3 base electrode, 13d...4th base electrode, 13e...5th base electrode, 13f...6th base electrode, 13g...7th base electrode, 13h...8th base electrode, 14...external electrode, 14a...1st external electrode, 14b...2nd external Electrode, 14c... Third external electrode, 14d... Fourth external electrode, 141... First part (end surface electrode part), 142... Second part (main surface electrode part), 15... Internal electrode, 15a... First internal electrode, 15b... Second internal electrode, 16 ...dielectric layer, 17a...first surface, 17b...second surface, 18a...first side surface, 18b...second side surface, 18c...third side surface, 18d...fourth side surface, 19a...first corner portion, 19b...second corner portion, 19c...third corner portion, 19d...fourth corner portion, 21...ceramic green sheet, 22...internal electrode sheet, 23...base electrode sheet, 24...base laminate, 25...planned cutting line, 26...element component, 27...laminated body, 27a...capacitance forming portion, 27b,27c...cover portion, 28...base electrode, 28a...first base electrode, 28b...second base electrode, 28c...third base electrode, 28d...fourth base electrode, 28e...fifth base electrode, 28f...sixth base electrode, 28g...seventh base electrode, 28h...eighth base electrode, 29...external electrode, 29a...first external electrode, 29b...second external electrode, 29c...third external electrode, 29d...fourth external electrode, 29e... Fifth external electrode, 29f...sixth external electrode, 29g...seventh external electrode, 29h...eighth external electrode, 291...first portion (end surface electrode portion), 292...second portion (main surface electrode portion), 30...internal electrode, 30a...first internal electrode, 30b...second internal electrode, 31...dielectric layer, 32a...first surface, 32b...second surface, 33a...first end surface, 33b...second end surface, 34a...first side surface, 34b...second side surface.

Claims

1. a laminate having a plurality of internal electrodes and a plurality of dielectric layers alternately stacked, and having a first surface and a second surface opposing each other in a stacking direction; a base electrode located on the first surface; an external electrode connected to a first internal electrode exposed on a surface of the laminate among the plurality of internal electrodes and connected to the base electrode, the average particle size of the metal particles contained in the base electrode is larger than the average particle size of the metal particles contained in the first internal electrode; Multilayer electronic components.

2. The external electrodes are plating layers. The multilayer electronic component according to claim 1 .

3. the first internal electrode and the base electrode are mainly composed of Ni, and the external electrode is mainly composed of Cu; The multilayer electronic component according to claim 1 .

4. an average particle size of metal particles at a position in the base electrode that is spaced a predetermined distance in the stacking direction from a surface opposite to the surface on the laminate side is larger than an average particle size of metal particles at a position in the first internal electrode that is spaced a predetermined distance from the surface of the laminate in a predetermined direction intersecting the stacking direction; The multilayer electronic component according to claim 1 .

5. the dimension in the stacking direction is smaller than the dimension in a predetermined direction intersecting the stacking direction and smaller than the dimension in a width direction perpendicular to the stacking direction and the predetermined direction; The multilayer electronic component according to claim 1 .

6. The predetermined distance is 0.5 μm to 1.5 μm. The multilayer electronic component according to claim 4 .

7. the base electrode is thicker than each of the plurality of internal electrodes; The multilayer electronic component according to claim 1 .

8. the base electrode is embedded in the laminate, with a surface thereof opposite to the laminate in the stacking direction exposed to the outside of the laminate; The multilayer electronic component according to claim 1 .

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