Multilayer electronic component

Abstract

The multilayer electronic component includes a laminate in which internal electrodes and dielectric layers are laminated, a base electrode, and an external electrode. The internal electrodes have a first internal electrode and a second internal electrode, the base electrode has a first base electrode and a second base electrode, and the external electrode has a first external electrode and a second external electrode. Each of the first external electrode and the second external electrode has a first portion connected to the first internal electrode or the second internal electrode and a second portion connected to any of the base electrodes. The average particle diameter of the metal particles contained in the first portion is smaller than the average particle diameter of the metal particles M contained in the second portion.

Description

Technical Field

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

Background Art

[0002] A multilayer ceramic capacitor, which is an example of a multilayer electronic component, includes a laminate in which a plurality of internal electrodes and a plurality of dielectric layers are alternately laminated, and external electrodes located on the surface of the laminate. By forming the external electrodes by a direct plating method, the thickness of the external electrodes can be reduced, so that it is possible to miniaturize and thin the multilayer ceramic capacitor without reducing the capacitance (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The multilayer electronic component of the present disclosure includes a laminate, a plurality of base electrodes, and a plurality of external electrodes. The laminate has a plurality of internal electrodes and a plurality of dielectric layers that are alternately laminated, and has a first surface and a second surface that face each other in the lamination direction, and a wall surface that faces in a predetermined direction intersecting the lamination direction. The plurality of external electrodes include a first external electrode located at least over the first surface from the wall surface. The first external electrode has a first portion connected to an internal electrode exposed on the wall surface among the plurality of internal electrodes, and a second portion connected to a base electrode located on the first surface among the plurality of base electrodes. The average particle diameter of the metal particles included in the first portion is smaller than the average particle diameter of the metal particles included in the second portion.

Brief Description of the Drawings

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Embodiments for Carrying Out 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, which is an example of a multilayer electronic component, will be described. However, the multilayer electronic component of the present disclosure is not limited to a multilayer ceramic capacitor and can be applied to various 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 on the drawings do not necessarily match the actual ones. In this specification, in some drawings, for convenience, an orthogonal coordinate system xyz is defined. 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 the stacking direction. Hereinafter, with the positive side of the z-axis direction being the upper side, terms such as the upper surface or the lower surface may be used.

[0007] Regarding the embodiments described relatively later, the description will focus on the differences from the embodiments described relatively earlier. For matters not particularly mentioned, the description of the embodiments described earlier may be incorporated or analogized from the description of the embodiments described earlier. Also, the description of any embodiment may be applied to other embodiments as long as there are no contradictions.

[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 of FIG. 1. FIG. 3 is a view showing an example of a cross-section cut along the cutting plane line III-III of FIG. 1, and FIG. 4 is a view showing another example of the cross-section cut along the cutting plane line III-III of FIG. 1. FIG. 5 is an enlarged cross-sectional view showing an enlarged view of a portion V in FIG. 3, and FIG. 6 is an enlarged cross-sectional view showing an enlarged view of a portion VI in FIG. 3. FIG. 7 is an electron micrograph for explaining the measurement of the particle size of metal particles included in the second portion of the external electrode and the underlying electrode. FIG. 8 is an electron micrograph for explaining the measurement of the particle size of metal particles included in the first portion of the external electrode and the internal electrode. In FIG. 2, for ease of illustration, hatching is applied to the underlying electrode and the ends of the internal electrodes exposed on the surface of the laminate. FIG. 5 is a view showing a portion V in the cross-section of the multilayer ceramic capacitor according to the first embodiment, but is also a view showing a portion corresponding to the portion V in the cross-section of the multilayer ceramic capacitors according to the second to fourth embodiments. The same applies to FIG. 6. In FIGS. 5 and 6, a part of the metal particles included in the external electrode is illustrated, and the illustration of the metal particles included in the underlying electrode and the internal electrode is omitted.

[0009] As shown in FIGS. 1 to 3, the multilayer ceramic capacitor 10 according to 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 underlying electrodes 3. The multilayer ceramic capacitor 10 may be a thin-type 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 laminating a plurality of internal electrodes 5 and a plurality of dielectric layers 6. The laminate 2 may be substantially rectangular parallelepiped as shown in FIG. 2. The laminate 2 has a first surface 7a and a second surface 7b that face each other in the lamination 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 face 8a and a second end face 8b that face each other in the length direction (x-axis direction) orthogonal to the lamination direction, and a first side face 9a and a second side face 9b that face each other in the width direction (y-axis direction) orthogonal to the lamination 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, 7b, the first end face 8a and the second end face 8b may be collectively referred to as the end faces 8a, 8b, and the first side face 9a and the second side face 9b may be collectively referred to as the side faces 9a, 9b. The main surfaces 7a, 7b may be perpendicular to the lamination direction. The end faces 8a, 8b may be perpendicular to the length direction. The side faces 9a, 9b may be perpendicular to the width direction.

[0011] The dielectric layer 6 is made of a ceramic material mainly composed of, for example, BaTiO3 (barium titanate), CaTiO3 (calcium titanate), SrTiO3 (strontium titanate), BaZrO3 (barium zirconate), CaZrO3 (calcium zirconate), or the like. The ceramic material may contain sub-components such as, for example, Mn (manganese) compounds, Mg (magnesium) compounds, Si (silicon) compounds, Co (cobalt) compounds, Ni compounds, and rare earth compounds. The dielectric layer 6 may have a thickness of, for example, about 0.1 to 1.0 μm.

[0012] As shown in FIGS. 2 and 3, the plurality of internal electrodes 5 include a plurality of first internal electrodes 5a and a plurality of second internal electrodes 5b. The end of the first internal electrode 5a is exposed on the first end face 8a. The end of the second internal electrode 5b is exposed on the second end face 8b. The first internal electrode 5a and the second internal electrode 5b have different polarities. In other words, when the first internal electrode 5a has a first polarity, the second internal electrode 5b has a second polarity different from the first polarity.

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

[0014] As shown in FIG. 3, the laminate 2 may be configured to include a capacitance forming portion 2a and cover portions 2b and 2c. The capacitance forming portion 2a is formed by alternately laminating a plurality of internal electrodes 5 and a plurality of dielectric layers 6 to form capacitance. The cover portions 2b and 2c are respectively located at both ends of the capacitance forming portion 2a in the lamination direction. The cover portions 2b and 2c may be composed of one or more dielectric layers and do not necessarily form 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 (less than the number of dielectric layers) dummy layers located therebetween. Each dummy layer may include a plurality of dummy electrodes. The plurality of dummy electrodes of each dummy layer may overlap the plurality of base electrodes 3 in a plan view. In other words, the plurality of dummy electrodes may be provided in the same number, substantially the same position, and substantially the same shape (including dimensions) as the plurality of base electrodes 3. The plurality of dummy electrodes may be exposed to the outside from any of the end faces 8a and 8b and side faces 9a and 9b of the laminate 2. The plurality of external electrodes 4 may be connected to the exposed portions. The plurality of dummy electrodes do not necessarily form capacitance. The material (components) and microstructure of the plurality of dummy electrodes may be the same as those of the base electrode 3, may be the same as those of the internal electrode 5, or may be different from both. For the sake of convenience, there may be an expression as if the cover portions 2b and 2c are composed only of dielectric layers, ignoring the presence or absence of the dummy layers.

[0016] The cover portions 2b and 2c (their dielectric layers) are made of a ceramic material mainly composed of, 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 constituting the dielectric layer 6.

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

[0018] As shown in FIGS. 2 and 3, the first base electrode 3a and the second base electrode 3b are separated from each other. The dimension of the first base electrode 3a in the length direction (x-axis direction) may be about 5 to 30% of the dimension of the laminate 2 in the length 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 plan 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 plan view.

[0019] The base electrode 3 is made of a metal material mainly composed of, for example, Ni, Cu, Sn, etc. The base electrode 3 may be made of the same metal material as the metal material constituting the internal electrode 5. The base electrode 3 may contain a ceramic material such as, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. In this case, it becomes easy to enhance the adhesion between the base electrode 3 and the laminate 2. The base electrode 3 may be thicker than a single 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 underlying electrode 3 may include a third underlying electrode 3c and a fourth underlying electrode 3d. The third underlying electrode 3c is located near the first end face 8a on the second surface 7b. The fourth underlying electrode 3d is located near the second end face 8b on the second surface 7b. The third underlying electrode 3c may have the same configuration as the first underlying electrode 3a except that it is located on the second surface 7b. The fourth underlying electrode 3d may have the same configuration as the second underlying 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 over at least the first surface 7a and is connected to the plurality of first internal electrodes 5a and the first underlying electrode 3a. The first external electrode 4a may cover the first underlying electrode 3a.

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

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

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

[0026] The external electrode 4 may be a plating layer formed directly on the laminate 2 by a plating method. The direct plating method is a method of applying at least a part of the plating layer to a surface where no underlying conductor layer is located (here, the surface of the laminate 2 composed of a dielectric). By adopting the direct plating method, the thickness of the external electrode 4 can be reduced. As a result, the multilayer ceramic capacitor 10 can be miniaturized without reducing the capacitance of the multilayer ceramic capacitor 10. The thickness of the external electrode 4 may be, for example, about 5 to 20 μm. The external electrode 4 can be formed using a plating method such as electroless plating or electrolytic plating. The external electrode 4 may be composed of a metal material mainly containing Cu, Ni, Sn, etc.

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

[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 a first layer 4aa, 4ba connected to the underlying electrode 3 and the internal electrode 5, and a second layer 4ab, 4bb covering the first layer 4aa, 4ba. The external electrode 4 may be composed of a first layer 4aa, 4ba connected to the underlying electrode 3 and the internal electrode 5, a second layer 4ab, 4bb covering the first layer 4aa, 4ba, and a third layer (not shown) covering the second layer 4ab, 4bb. In this case, the first layer 4aa, 4ba may be formed by the direct plating method.

[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 faces 8a, 8b of the laminate 2 and is connected to a plurality of first internal electrodes 5a or a plurality of 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 be further located on the second surface 7b and may 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 face electrode portion. The second portion 42 is also referred to as a main surface electrode portion.

[0030] The end face electrode portion 41 of the first external electrode 4a is located on the first end face 8a and is connected to the ends of the plurality of first internal electrodes 5a that are exposed on the first end face 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 may 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 face electrode portion 41 of the second external electrode 4b is located on the second end face 8b and is connected to the ends of the plurality of second internal electrodes 5b that are exposed on the second end face 8b. The main 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 main surface electrode portion 42 of the second external electrode 4b may cover the second base electrode 3b. The main surface electrode portion 42 of the second external electrode 4b may be located on the first surface 7a and the second surface 7b and may be connected to the second base electrode 3b and the fourth base electrode 3d. The main 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 electrode 4 contains metal particles M. The multilayer ceramic capacitor 10 is configured such that the average particle diameter of the metal particles M contained in the end face electrode portion 41 is smaller than the average particle diameter of the metal particles M contained in the main face electrode portion 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 the circuit board. However, stress is likely to be applied to the main face electrode portion 42 that extends substantially parallel to the mounting surface, and cracks are likely to occur. Since the average particle diameter of the metal particles contained in the main face electrode portion 42 of the multilayer ceramic capacitor 10 is relatively large, the grain boundary area (the grain boundary area of the metal particles M) that is likely to be the starting point of cracks can be reduced, and the mechanical strength of the main face electrode portion 42 can be improved. As a result, the possibility of cracks occurring in the main face electrode portion 42 can be reduced, and the reliability of the multilayer ceramic capacitor 10 can be improved.

[0033] Also, since the average particle diameter of the metal particles M contained in the end face electrode portion 41 of the multilayer ceramic capacitor 10 is relatively small, the contact area between the metal particles M contained in the end face electrode portion 41 and the metal particles contained in the internal electrode 5 can be increased. As a result, the end face electrode portion 41 and the internal electrode 5 can be connected well, and the electrical characteristics of the multilayer ceramic capacitor 10 can be improved.

[0034] As shown in FIG. 4, in the aspect where the external electrode 4 has a plurality of metal layers (plated layers), the end face electrode portion 41 and the main face electrode portion 42 may be a part of the metal layer closest to the laminate 2, or may be a part of two or more metal layers (for example, two layers on the laminate 2 side in a three-layer structure), or may be a part of all the metal layers. In other words, the matter that the average particle diameter of the metal particles M on the end face side is smaller than the average particle diameter of the metal particles M on the main face side may hold only in one layer closest to the laminate 2, or may hold only in two or more layers (not all layers) selected from the laminate 2 side, or may hold in all layers. Note that, different from the above, it may be an essential requirement that it holds in one layer closest to the laminate 2, or it may be an essential requirement that it holds in two or more metal layers (not all layers) selected from the laminate 2 side, or it may be an essential requirement that it holds in all layers.

[0035] Further, when the end face electrode portion 41 and the main face electrode portion 42 are a part of two or more metal layers, the matter that the average particle diameter of the metal particles M on the end face side is smaller than the average particle diameter of the metal particles M on the main face side may hold in each of the two or more target metal layers, and / or may hold with respect to the average particle diameter of the entire two or more metal layers.

[0036] Note that the descriptions in the penultimate paragraph and the previous paragraph may be applied not only to the matter that the average particle diameter of the metal particles M on the end face side is smaller than the average particle diameter of the metal particles M on the main face side, but also to other matters regarding the particle diameter, as long as there is no contradiction. For example, the matter that the particle diameter becomes smaller or larger as it approaches the laminate 2 described later may hold only in one layer closest to the laminate 2, or may hold only in two or more layers (not all layers) selected from the laminate 2 side, or may hold in all layers. Alternatively, either one may be an essential requirement. The specific example (μm) of the average particle diameter or the description of the material may be applied only to one layer closest to the laminate 2, or may be applied to two or more layers (not all layers) selected from the laminate 2 side, or may be applied to all layers.

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

[0038] The base electrode 3 and the internal electrode 5 may mainly contain Ni, and the external electrode 4 may mainly contain Cu. In this case, metal particles made of a Cu-Ni alloy can be formed in the region near the interface between the base component 1 and the external electrode 4, and the average particle diameter of the metal particles can be made relatively large. As a result, the mechanical strength of the main face electrode portion 42 can be improved, and it becomes easy to enhance the adhesion between the base component 1 and the external electrode 4.

[0039] The average particle diameter of the metal particles M at the position P separated by a predetermined distance L1 from the surface on the laminate 2 side in the end face electrode portion 41 may be smaller than the average particle diameter of the metal particles M at the position Q separated by the predetermined distance L1 from the surface on the laminate 2 side in the main face electrode portion 42 (see FIGS. 5 and 6). The predetermined distance L1 may be, for example, 0.5 to 1.5 μm, or may be 1 μm. Since the average particle diameter of the metal particles M in the region near the base electrode 3 in the main face electrode portion 42 is relatively large, the possibility of cracks occurring in this region can be reduced, and the reliability of the multilayer ceramic capacitor 10 can be improved. Also, since the average particle diameter of the metal particles M in the region near the internal electrode 5 in the end face electrode portion 41 is relatively small, the end face electrode portion 41 and the internal electrode 5 can be well connected, and the electrical characteristics of the multilayer ceramic capacitor 10 can be improved.

[0040] The average particle diameter of the metal particles M at the position P is, in other words, the average value of the particle diameters of the plurality of metal particles M straddling the position P. Similarly, the average particle diameter of the metal particles M at the position Q is the average value of the particle diameters of the plurality of metal particles M straddling the position Q. The same applies to the average particle diameter of the metal particles at the position S or R described later.

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

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

[0043] Note that as approaching the laminate 2, the fact that the particle size of the metal particles M becomes smaller does not necessarily mean that the particle sizes of all the metal particles M are strictly in such a relationship. For example, for three or more, ten or more, or fifty or more of the metal particles M included in the end face electrode portion 41, if the particle sizes are in such a relationship, it is sufficient. Also, for example, in the measurement results of the particle sizes of a predetermined number of metal particles M, 60% or more, or 80% or more of the metal particles M may be in such a relationship. In other words, from a predetermined number of randomly selected metal particles M, the metal particles M in such a relationship may be extractable in a number of 60% or more, or 80% or more of the predetermined number. The larger the predetermined number, the higher the accuracy of whether such a relationship holds, but for example, it may be 10, 50, or 100. The comparison of the positions of the metal particles M may be based on the geometric center. Also, for example, if the end face electrode portion 41 is bisected into two regions in the thickness direction, and 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, it may be determined that such a relationship holds. Instead of bisecting, it may be trisected or pentasected. Whether the metal particles M belong to any region may be determined based on the geometric center of the metal particles M. In any of the measurements and determinations, with regard to whether such a relationship holds, extremely small particles compared to the surrounding particles may be ignored.

[0044] The main surface electrode portion 42 may have the particle size of the metal particles M included in the main surface electrode portion 42 becoming larger as approaching the laminate 2. In this case, since the average particle size of the metal particles M included in the region near the base electrode 3 in the main surface electrode portion 42 is relatively large, the risk of cracks occurring in the region closer to the laminate 2 and more likely to affect the electrical characteristics can be further reduced, and the reliability of the multilayer ceramic capacitor 10 can be further improved. Note that as approaching the laminate 2, the fact that the particle size of the metal particles M becomes larger does not necessarily mean that the particle sizes of all the metal particles M are strictly in such a relationship. In this regard, the description in the previous paragraph may be incorporated. For example, for three or more, ten or more, or fifty or more of the metal particles M included in the main surface electrode portion 42, if the particle sizes are in such a relationship, it is sufficient.

[0045] The multilayer ceramic capacitor 10 may be configured such that the average particle diameter of the metal particles contained in the base electrode 3 is larger than the average particle diameter of the metal particles contained in the internal electrode 5. Since the average particle diameter of the metal particles contained in the base electrode 3 is relatively large, the possibility of cracks occurring in the region near the external electrode 4 in the base electrode 3 can be reduced, and the reliability of the multilayer ceramic capacitor 10 can be improved. Further, since the average particle diameter 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 face electrode portion 41) can be increased. As a result, the external electrode 4 and the internal electrode 5 can be favorably 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 diameter of the metal particles at a position S separated by a predetermined distance L' from the surface of the base electrode 3 on the side opposite to the laminated body 2 side is larger than the average particle diameter of the metal particles at a position R separated by a predetermined distance L' from the surface (end faces 8a, 8b) of the laminated body 2 in the internal electrode 5 (see FIGS. 5 and 6). The predetermined distance L' may be, for example, 0.5 to 1.5 μm, or may be 1 μm. Since the average particle diameter of the metal particles contained in the region near the external electrode 4 (main surface electrode portion 42) in the base electrode 3 is relatively large, the possibility of cracks occurring in this region can be reduced, and the reliability of the multilayer ceramic capacitor 10 can be improved. Further, since the average particle diameter of the metal particles contained in the region near the external electrode 4 (end face electrode portion 41) in the internal electrode 5 is relatively small, the internal electrode 5 and the external electrode 4 can be favorably connected, and the electrical characteristics of the multilayer ceramic capacitor 10 can be improved.

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

[0048] First, using a FIB-SEM (Focused Ion Beam Scanning Electron Microscope), a cross-section of the multilayer ceramic capacitor 10 is taken, and an electron micrograph of the cross-section is captured. FIGS. 7 and 8 show electron micrographs of the cross-section of the multilayer ceramic capacitor 10 taken at a magnification of 15,000 times. FIG. 7 corresponds to the electron micrograph of the V portion 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 the electron micrograph of the VI portion in FIG. 3, and B2 in FIG. 8 indicates the interface between the external electrode 4 (end face electrode portion 41) and the laminate 2. In this measurement, as the FIB-SEM, Helios 5UC manufactured by Thermo Fisher Scientific was used, and the analysis conditions were an acceleration voltage of 30 kV and an irradiation current of 80 pA.

[0049] Next, regarding the electron micrographs in FIGS. 7 and 8, using an image analysis program, as shown by the dashed lines in FIGS. 7 and 8, a boundary line along the outer shape of the metal particles is drawn. To measure the particle size of the metal particles, the area of the region surrounded by the boundary line may be calculated, and the equivalent circle diameter of the area may be 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 may be calculated, and their arithmetic mean value may be taken as the average particle size of the metal particles. N may be, for example, about 3 to 15, or may be about 10. The same applies to the average particle size of the metal particles contained in each of the end face electrode portion 41, the base electrode 3, and the internal electrode 5.

[0050] N may be more than those described above. For example, it may be 20, 50, or 100. Also, the average particle size may be measured by analyzing the entire cross-section of the target electrode (or part or region), or may be the average value of the particle sizes measured by analyzing a plurality of partial regions of the cross-section. The plurality of partial regions may be, for example, 3 or more, or 5 or more, may have the same approximate area as each other, and may be set at equal intervals in the left-right direction and / or at equal intervals in the thickness direction. Further, the average particle size may be a value in one cross-section at a specific position (e.g., a representative position such as the central position) of the target (such as an electrode) with respect to the direction orthogonal to the cross-section, or may be the average value in a plurality of (e.g., 3 or more, or 5 or more) cross-sections obtained by equally dividing the target. Regarding the latter, when it is difficult to equally divide one target, measurements may be made on a plurality of cross-sections corresponding to the plurality of cross-sections obtained by the above equal division in a plurality of multilayer ceramic capacitors 10 having the same configuration, and an average value may be obtained. It should be noted that the fact that such a cross-section at a specific position may be referred to or a plurality of cross-sections may be referred to and an average value may be obtained is the same for other properties or index values.

[0051] Next, the multilayer ceramic capacitor according to the 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 the element component of the multilayer ceramic capacitor of FIG. 9, FIG. 11 is a cross-sectional view taken along the cutting plane line XI-XI of FIG. 9, and FIG. 12 is a cross-sectional view taken along the cutting plane line XII-XII of FIG. 9. In FIG. 10, for ease of illustration, hatching is applied to the end portions of the base electrode and the internal electrodes exposed on the surface of the laminate.

[0052] As shown in FIGS. 9 to 12, the multilayer ceramic capacitor 10A of the present embodiment includes an element component 11 and a plurality of external electrodes 14. The element component 11 includes a laminate 12 and a plurality of base electrodes 13, as shown in FIG. 2. The multilayer ceramic capacitor 10A may be a thin-type 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 laminating a plurality of internal electrodes 15 and a plurality of dielectric layers 16. As shown in FIG. 10, the laminate 12 may be substantially rectangular parallelepiped. The laminate 12 has a first surface 17a and a second surface 17b that face each other in the lamination 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) orthogonal to the lamination direction, and a third side surface 18c and a fourth side surface 18d that face each other in the width direction (y-axis direction) orthogonal to the lamination direction and the length direction. Hereinafter, the first surface 17a and the second surface 17b may be collectively referred to as the main surfaces 17a, 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 the side surfaces 18a to 18d. The main surfaces 17a, 17b may be perpendicular to the lamination direction. The first side surface 18a and the second side surface 18b may be perpendicular to the length direction. The third side surface 18c and the fourth side surface 18d may be perpendicular to the width direction.

[0054] As shown in FIGS. 10 and 11, the laminate 12 has a first corner portion 19a extending from the first side surface 18a to the third side surface 18c, a second corner portion 19b extending from the second side surface 18b to the fourth side surface 18d, a third corner portion 19c extending from the first side surface 18a to the fourth side surface 18d, and a fourth corner portion 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 mainly composed of, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The ceramic material may contain sub-components such as, for example, Mn compounds, Mg compounds, Si compounds, Co compounds, Ni compounds, rare earth compounds, etc. 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 plurality of internal electrodes 15 include a plurality of first internal electrodes 15a and a plurality of second internal electrodes 15b. The end portions of the first internal electrodes 15a are exposed at the first corner portions 19a and the second corner portions 19b. The end portions of the second internal electrodes 15b are exposed at the third corner portions 19c and the fourth corner portions 19d. The first internal electrodes 15a and the second internal electrodes 15b have different polarities. In other words, when the first internal electrodes 15a have a first polarity, the second internal electrodes 15b have a second polarity different from the first polarity.

[0057] The internal electrodes 15 are made of a metal material mainly composed of, for example, Ni, Cu, Sn, etc. 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 about 0.1 to 1.0 μm, for example.

[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 laminating a plurality of internal electrodes 15 and a plurality of dielectric layers 16 to form capacitance. The cover portions 12b and 12c are respectively located at both ends of the capacitance forming portion 12a in the lamination direction. The cover portions 12b and 12c are made of one or more dielectric layers and do not necessarily form capacitance.

[0059] The cover portions 12b and 12c (their dielectric layers) are made of a ceramic material mainly composed of, 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 constituting 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 underlying electrode 13a is located near the first corner portion 19a on the first surface 17a. In plan view, the first underlying electrode 13a may be substantially rectangular. Also, in plan view, the corner portion of the first underlying electrode 13a near the first corner portion 19a may overlap with the first corner portion 19a.

[0062] The second underlying electrode 13b is located near the second corner portion 19b on the first surface 17a. In plan view, the second underlying electrode 13b may be substantially rectangular. Also, in plan view, the corner portion of the second underlying electrode 13b near the second corner portion 19b may overlap with the second corner portion 19b.

[0063] The third underlying electrode 13c is located near the third corner portion 19c on the first surface 17a. In plan view, the third underlying electrode 13c may be substantially rectangular. Also, in plan view, the corner portion of the third underlying electrode 13c near the third corner portion 19c may overlap with the third corner portion 19c.

[0064] The fourth underlying electrode 13d is located near the fourth corner portion 19d on the first surface 17a. In plan view, the fourth underlying electrode 13d may be substantially rectangular. Also, in plan view, the corner portion of the fourth underlying electrode 13d near the fourth corner portion 19d may overlap with the fourth corner portion 19d.

[0065] The shape of the first underlying electrode 13a is not limited to being substantially rectangular, and may be substantially fan-shaped (substantially a quarter circle) or substantially a right triangle. In plan view, the center of the substantially fan-shaped (substantially a quarter circle) first underlying electrode 13a may overlap with the first corner portion 19a, or the right vertex of the substantially right triangle may overlap with the first corner portion 19a. The same applies to the second underlying electrode 13b, the third underlying electrode 13c, and the fourth underlying electrode 13d.

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

[0067] The plurality of external electrodes 14 includes 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 portion 19a over at least the first surface 17a and is connected to the plurality of first internal electrodes 15a and the first underlying electrode 13a. The first external electrode 14a may be located from the first corner portion 19a over the first surface 17a and the second surface 17b and may be connected to the plurality of first internal electrodes 15a, the first underlying electrode 13a, and the fifth underlying electrode 13e.

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

[0070] The third external electrode 14c is located from the third corner portion 19c over 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 portion 19c over the first surface 17a and the second surface 17b and may be 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 portion 19d over 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 portion 19d over the first surface 17a and the second surface 17b and may be connected to the plurality of second internal electrodes 15b, the fourth base electrode 13d, and the eighth base electrode 13h.

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

[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 a plurality of first internal electrodes 5a or a plurality of second internal electrodes 5b. The second portion 142 is located on the first main surface 17a and is connected to the first underlying electrode 13a, the second underlying electrode 13b, the third underlying electrode 13c, or the fourth underlying electrode 13d. The second portion 142 may completely cover the first underlying electrode 13a, the second underlying electrode 13b, the third underlying electrode 13c, or the fourth underlying electrode 13d. The second portion 142 may further be located on the second main surface 17b and may further be connected to the fifth underlying electrode 13e, the sixth underlying electrode 13f, the seventh underlying electrode 13g, or the eighth underlying electrode 13h. The first portion 141 is also referred to as an end face electrode portion, and the second portion 142 is also referred to as a main surface electrode portion.

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

[0076] The end face 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 plurality of first internal electrodes 15a exposed on the second side surface 18b and the fourth side surface 18d. The main 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 main surface electrode portion 142 of the second external electrode 14b may cover the second base electrode 13b. The main surface electrode portion 142 of the second external electrode 14b is located on the first surface 17a and the second surface 17b, and may be connected to the second base electrode 13b and the sixth base electrode 13f. The main 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 face 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 ends of the plurality of second internal electrodes 15b exposed on the first side surface 18a and the fourth side surface 18d. The main 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 main surface electrode portion 142 of the third external electrode 14c may cover the third base electrode 13c. The main surface electrode portion 142 of the third external electrode 14c is located on the first surface 17a and the second surface 17b, and may be connected to the third base electrode 13c and the seventh base electrode 13g. The main 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 face 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 plurality of second internal electrodes 15b exposed on the second side surface 18b and the third side surface 18c. The main 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 main surface electrode portion 142 of the fourth external electrode 14d may cover the fourth base electrode 13d. The main surface electrode portion 142 of the fourth external electrode 14d is 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 main 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 electrode 14 contains 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 face electrode portion 141 is smaller than the average particle size of the metal particles M contained in the main surface electrode portion 142. The effect thereof is the same as that of the first embodiment.

[0080] The average particle size of the metal particles M contained in the end face electrode portion 141 may be, for example, 0.3 to 0.8 μm, or may be 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 may be about 0.6 to 1.0 μm.

[0081] The base electrode 13 and the internal electrode 15 may mainly contain Ni, and the external electrode 14 may mainly contain Cu. The effect in this case is the same as that of the first embodiment.

[0082] The average particle size of the metal particles M at a position P separated by a predetermined distance L1 from the surface on the laminate 12 side in the end face electrode portion 141 may be smaller than the average particle size of the metal particles M at a position Q separated by the predetermined distance L1 from the surface on the laminate 12 side in the main surface electrode portion 142 (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 such a case is the same as that of the first embodiment.

[0083] The average particle size of the metal particles M contained in the end face 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. The effect in this case is the same as that of the first embodiment.

[0084] As the end face electrode portion 141 approaches the laminate 12, the particle size of the metal particles M contained in the end face electrode portion 141 may become smaller. The effect in this case is the same as that of the first embodiment. Similarly to the first embodiment, it is not necessarily required that the particle sizes of all the metal particles M are exactly in such a relationship. For example, the particle sizes of 3 or more, 10 or more, or 50 or more of the metal particles M contained in the end face electrode portion 141 may be measured, and it is sufficient if they are in such a relationship.

[0085] As the main surface electrode portion 142 approaches the laminate 12, the particle size of the metal particles M contained in the main surface electrode portion 142 may increase. The effects in this case are the same as those in the first embodiment. Similarly to the first embodiment, it is not necessarily required that the particle sizes of all the metal particles M are exactly in such a relationship. For example, the particle sizes of three or more, ten or more, or fifty or more of the metal particles M contained in the main surface electrode portion 142 may be measured, and it is sufficient if they are in such a 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. The effects in this case are the same as those in the first embodiment.

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

[0088] Hereinafter, a method for manufacturing the multilayer ceramic capacitor 10 will be described. The method for manufacturing the multilayer ceramic capacitor 10 includes a first step of producing a mother laminate, a second step of producing a body component, and a third step of forming an external electrode.

[0089] FIG. 13 is a perspective view for explaining an example of a step of producing a mother laminate, FIG. 14 is a perspective view showing an example of a mother laminate, and FIG. 15 is a perspective view showing a body component precursor obtained by cutting the mother laminate of FIG. 14. In FIGS. 13 to 15, for ease of illustration, hatching is applied to the internal electrode pattern, the base electrode pattern, the end portion of the internal electrode pattern exposed on the surface of the mother laminate, and the end portion of the internal electrode pattern exposed on the surface of the body component.

[0090] (First step) The first step is a step of manufacturing a mother laminate for constituting a base body component precursor. In the first step, first, raw material powder mainly composed of BaTiO3 is prepared. Subsequently, an organic vehicle is mixed with the prepared raw material powder to prepare a ceramic slurry. The organic vehicle used for preparing the ceramic slurry may be, for example, a resin such as a butyral resin dissolved in a solvent obtained by mixing ethyl alcohol and toluene. Subsequently, using the prepared ceramic slurry, a ceramic green sheet 21 that will become the dielectric layer 6 is formed 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 powder mainly composed of Ni to prepare a conductive paste. The organic vehicle used for preparing the conductive paste may be, for example, a resin such as ethyl cellulose dissolved in a solvent obtained by mixing a dihydroterpineol-based solvent and butyl cellosolve. A dispersant such as oleic acid or polyethylene glycol may be added to the conductive paste.

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

[0093] Next, as shown in FIG. 13, a temporary laminate is produced by laminating a predetermined number of internal electrode sheets 22 on the base electrode sheet 23 and further laminating the base electrode sheet 23. When producing the temporary laminate, a predetermined number of internal electrode sheets 22 may be laminated while being shifted by half of 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 the internal electrode sheet 22 printed with the same internal electrode pattern. Further, 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 circuit between the internal electrodes 5 having different polarities can be reduced.

[0094] Next, the temporary laminate is pressed in the lamination direction to produce a mother laminate 24 as shown in FIG. 14. The pressing of the temporary laminate can be performed using, for example, a hydrostatic press device. Note that the production of the temporary laminate and the mother laminate 24 may be performed on a support sheet (reference numeral omitted) as shown in FIGS. 13 and 14.

[0095] (Second step) The second step is a step of producing the body component 1. First, the mother laminate 24 is cut along the lattice-shaped cutting planned lines 25 to produce a plurality of precursors of the body component 1 (hereinafter also referred to as the body component precursor 1p) as shown in FIG. 15. The cutting of the mother laminate 24 can be performed using, for example, a guillotine cutter, a dicing saw device, or the like. Note that since the body component precursor 1p has substantially the same structure as the body component 1, in the following description, terms and reference numerals such as the first surface 7a, the first end surface 8a, the base electrode 3, and the internal electrode 5 may also be used for the body component precursor 1p.

[0096] Subsequently, the green body part precursor 1p is fired. The firing temperature may be appropriately set according to the ceramic material contained in the ceramic green sheet, the metal material contained in the conductive paste, etc., and may be, for example, about 1100 to 1250 °C. Note that a debinding process may be performed on the green body part precursor 1p before firing. The debinding process may be performed in an air atmosphere, an inert gas atmosphere, or a reducing atmosphere. The debinding process may be performed under atmospheric pressure or under reduced pressure. Further, a reoxidation process may be performed on the green body part precursor 1p after firing.

[0097] Subsequently, the green body part precursor 1p is put into a rotating pot containing an abrasive, and barrel polishing is performed to remove burrs on the surface of the green body part precursor 1p, round the corners, and sufficiently expose the ends of the internal electrodes 5 at the end faces 8a, 8b of the laminate 2. In this way, the green body part 1 as shown in FIG. 2 can be manufactured.

[0098] (Third step) The third step is a step of forming the external electrodes 4 on the base body component 1. First, for example, using a plating method such as electroless plating or electrolytic plating, a plating layer that will become the external electrode 4 is formed on the base body component 1 to produce a precursor of the multilayer ceramic capacitor 10 (hereinafter also referred to as a capacitor precursor). The plating layer includes 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 positioned from the first end face 8a over the first surface 7a, the second surface 7b, the first side face 9a, and the second side face 9b and is formed so as to be connected to the plurality of first internal electrodes 5a, the first base electrode 3a, and the third base electrode 3c. Also, the second plating layer is positioned from the second end face 8b over the first surface 7a, the second surface 7b, the first side face 9a, and the second side face 9b and is formed so as to be connected to the plurality of second internal electrodes 5b, the second base electrode 3b, and the fourth base electrode 3d. When forming the plating layer, the first plating layer may be formed so as to completely cover the first base electrode 3a and the third base electrode 3c, and the second plating layer may be formed so as to completely cover the second base electrode 3b and the fourth base electrode 3d. Also, 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] Subsequently, by subjecting the capacitor precursor to an annealing treatment, the metal particles contained in the portion located on the main surfaces 7a, 7b of the plating layer and connected to the base electrode 3 (hereinafter, also referred to as the main surface electrode portion 42 for convenience) are grown in grain size. When performing the annealing treatment, heat is made to be more easily transmitted to the main surface electrode portion 42 than to the portion located on the end faces 8a, 8b of the plating layer and connected to the internal electrode 5 (hereinafter, also referred to as the end face electrode portion 41 for convenience). Thereby, it is possible to suppress the grain growth of the metal particles in the end face electrode portion 41 while promoting the grain growth of the metal particles in the main surface electrode portion 42. As a result, it is possible to form the external electrode 4 in which the average particle diameter of the metal particles contained in the main surface electrode portion 42 is larger than the average particle diameter of the metal particles contained in the end face electrode portion 41.

[0100] The conditions for the annealing treatment may be, for example, a heating 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. In order to suppress the grain growth of the metal particles in the end face electrode portion 41 while promoting the grain growth of the metal particles in the main face electrode portion 42, the capacitor precursor may be arranged in the annealing furnace so that heat is efficiently transferred from the end face electrode portion 41 to the main face electrode portion 42. Alternatively, the annealing treatment may be performed while pressing the capacitor precursor in the stacking direction. Thereby, the grain growth of the metal particles in the pressed main face electrode portion 42 can be promoted, and thus the particle size of the metal particles in the main face electrode portion 42 can be made larger than the particle size of the metal particles in the end face electrode portion 41. In order to press the capacitor precursor in the stacking direction, for example, a pair of substrates or a pair of sheets may be arranged so as to sandwich the capacitor precursor in the stacking direction, and the capacitor precursor may be pressed in the stacking direction through the pair of substrates or the pair of sheets. Alternatively, the annealing treatment may be performed with a plurality of capacitor precursors stacked in the stacking direction.

[0101] In the main face electrode portion 42, the method of increasing the particle size of the metal particles M contained in the main face electrode portion 42 as approaching the laminate 2 is arbitrary. For example, as already mentioned, the material of the external electrode 4 is Cu, the material of the base electrode 3 is Ni, and Cu and Ni may be alloyed and grain-grown at the interface between the two by annealing treatment. At this time, since the end face electrode portion 41 only contacts the internal electrode 5 in a partial region, even if the material of the internal electrode 5 is Ni, it is also possible to make the particle size increase as approaching the laminate 2 only in the main face electrode portion 42. And / or when forming the external electrode 4 with two or more plating layers, the type and conditions of the plating method and the like may be changed so that the particle size becomes larger for the layer closer to the laminate 2. At this time, by performing at least a part of the plating layer forming process separately for the end face electrode portion 41 and the main face electrode portion 42, it is also possible to make the particle size increase as approaching the laminate 2 only in the main face electrode portion 42.

[0102] In the end face electrode portion 41, the method of reducing the particle size of the metal particles M contained in the end face electrode portion 41 as approaching the laminate 2 is arbitrary. For example, by making the temperature of the outer surface of the end face electrode portion 41 higher than that of the inner surface during the annealing treatment, grain growth may be promoted on the outer surface side rather than on the inner surface side. And / or when forming the external electrode 4 (at least the end face electrode portion 41) with two or more plating layers, the type and conditions of the plating method may be changed so that the particle size becomes smaller in the layer closer to the laminate 2.

[0103] The method of making 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 is arbitrary. 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 particle size of the metal particles contained in the conductive paste to be the base electrode 3 may be made larger than the particle size of the metal particles contained in the conductive paste to be the internal electrode 5.

[0104] In the above manner, the multilayer ceramic capacitor 10 of the first embodiment can be manufactured. Also, the multilayer ceramic capacitor 10A of the second embodiment can be manufactured by a manufacturing method similar to the manufacturing method of the multilayer ceramic capacitor 10.

[0105] As described above in detail for the embodiments of the present disclosure, the present disclosure is not limited to the above-described embodiments, and various changes, improvements, etc. are possible without departing 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 FIGS. 16 to 19, or may be the multilayer ceramic capacitor of the fourth embodiment shown in FIGS. 20 to 23. Hereinafter, the multilayer ceramic capacitors of the third embodiment and the fourth embodiment will be described.

[0107] FIG. 16 is a perspective view showing a multilayer ceramic capacitor according to the third embodiment, FIG. 17 is a perspective view showing the body component of the multilayer ceramic capacitor of FIG. 16, FIG. 18 is a view showing an example of a cross section cut along the cutting plane line XVIII-XVIII of FIG. 16, and FIG. 19 is a view showing an example of a cross section cut along the cutting plane line XIX-XIX of FIG. 16. FIG. 20 is a perspective view showing a multilayer ceramic capacitor according to the fourth embodiment, FIG. 21 is a perspective view showing the body component of the multilayer ceramic capacitor of FIG. 20, FIG. 22 is a view showing an example of a cross section cut along the cutting plane line XXII-XXII of FIG. 20, and FIG. 23 is a view showing an example of a cross section cut along the cutting plane line XXIII-XXIII of FIG. 20.

[0108] As shown in FIG. 16, the multilayer ceramic capacitor 10B according to the third embodiment includes a body component 26 and a plurality of external electrodes 29. As shown in FIG. 17, the body component 26 includes a laminate 27 and a plurality of base electrodes 28. The multilayer ceramic capacitor 10B may be a thin-type 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 laminating a plurality of internal electrodes 30 and a plurality of dielectric layers 31. The laminate 27 may be substantially rectangular parallelepiped. The laminate 27 has a first surface 32a and a second surface 32b that face each other in the lamination direction, a first end surface 33a and a second end surface 33b that face each other in the length direction, and a first side surface 34a and a second side surface 34b that face each other in the width direction.

[0110] The dielectric layer 31 is made of a ceramic material mainly composed of, for example, BaTiO3, CaTiO3, SrTiO3, BaZrO3, CaZrO3, etc. The ceramic material may contain sub-components such as, for example, Mn compounds, Mg compounds, Si compounds, Co compounds, Ni compounds, rare earth compounds, etc. The dielectric layer 31 may have a thickness of about 0.1 to 1.0 μm, for example.

[0111] As shown in FIGS. 17 to 19, the plurality of internal electrodes 30 have a plurality of first internal electrodes 30a and a plurality of second internal electrodes 30b. The end of the first internal electrode 30a is exposed at the first end face 33a and the second end face 33b. The end of the second internal electrode 30b is exposed at the first side face 34a and the second side face 34b. The first internal electrode 30a and the second internal electrode 30b have different polarities from each other.

[0112] The internal electrode 30 is made of a metal material mainly composed of, for example, Ni, Cu, Sn, etc. 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 about 0.1 to 1.0 μm, for example.

[0113] As shown in FIGS. 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 laminating a plurality of internal electrodes 30 and a plurality of dielectric layers 31 to form a capacitance. The cover portions 27b and 27c are respectively located at both ends of the capacitance forming portion 27a in the lamination direction. The cover portions 27b and 27c may be composed 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 mainly composed of, 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 constituting the dielectric layer 31.

[0115] The plurality of base electrodes 28 includes 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 near the first end face 33a on the first surface 32a, and the second base electrode 28b is located near the second end face 33b on the first surface 32a. The third base electrode 28c is located near the first side face 34a on the first surface 32a, and the fourth base electrode 28d is located near the second side face 34b on the first surface 32a. The third base electrode 28c and the fourth base electrode 28d may be located at the central portion of the first surface 32a in the longitudinal direction. The third base electrode 28c and the fourth base electrode 28d may be, for example, substantially semi-circular, substantially rectangular, substantially triangular, etc. in a plan view.

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

[0117] As shown in FIG. 16, the plurality of external electrodes 29 includes 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 over at least the first surface 32a and is connected to a 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 may be located from the first end face 33a over the first surface 32a and the second surface 32b and may be connected to a 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 over the first surface 32a, the second surface 32b, the first side face 34a, and the second side face 34b.

[0119] The second external electrode 29b is located from the second end face 33b over at least the first surface 32a and is connected to a 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 may be located from the second end face 33b over the first surface 32a and the second surface 32b and may be connected to a 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 over the first surface 32a, the second surface 32b, the first side face 34a, and the second side face 34b.

[0120] The third external electrode 29c is located from the first side face 34a over at least the first surface 32a and is connected to a 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 may be located from the first side face 34a over the first surface 32a and the second surface 32b and may be connected to a 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 over at least the first surface 32a and is connected to a 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 over the first surface 32a and the second surface 32b and may be connected to a 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 electroplating. 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 electroplating directly.

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

[0124] Next, the multilayer ceramic capacitor of the fourth embodiment will be described. In the following description, for the same configurations as those of the multilayer ceramic capacitor of the third embodiment, the same terms and the same reference numerals are used, and detailed descriptions thereof are omitted.

[0125] As shown in FIG. 20, the multilayer ceramic capacitor 10C of the fourth embodiment includes a body component 26 and a plurality of external electrodes 29. As shown in FIG. 21, the body 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] As shown in FIGS. 21 to 23, the laminate 27 is formed by alternately laminating a plurality of internal electrodes 30 and a plurality of dielectric layers 31. The laminate 27 may be substantially rectangular parallelepiped. 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 include a plurality of first internal electrodes 30a and a plurality of second internal electrodes 30b.

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

[0129] As shown in FIGS. 22 and 23, the laminate 27 may be configured to include a capacitance forming portion 27a and cover portions 27b and 27c. The capacitance forming portion 27a is formed by alternately laminating a plurality of internal electrodes 30 and a plurality of dielectric layers 31 to form capacitance. The cover portions 27b and 27c are respectively located at both ends of the capacitance forming portion 27a in the lamination direction. The cover portions 27b and 27c may be composed of one or more dielectric layers and do not necessarily form capacitance.

[0130] The plurality of base electrodes 28 includes 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 to fourth base electrodes 28a to 28d are located closer to the first side surface 34a on the first surface 32a. The fifth to eighth base electrodes 28e to 28h are located closer to the second side surface 34b on the first surface 32a.

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

[0132] As shown in FIG. 20, the plurality of external electrodes 29 includes 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 over at least the first surface 32a and are connected to a plurality of second internal electrodes 30b. The first external electrode 29a and the third external electrode 29c are respectively connected to the first base electrode 28a and the third base electrode 28c. The first external electrode 29a and the third external electrode 29c may respectively cover the first base electrode 28a and the third base electrode 28c. The first external electrode 29a is located from the first side surface 34a over the first surface 32a and the second surface 32b and may be connected to the first base electrode 28a and the ninth base electrode. The first external electrode 29a may cover the first base electrode 28a and the ninth base electrode. The third external electrode 29c is located from the first side surface 34a over the first surface 32a and the second surface 32b and may be connected to the third base electrode 28c and the eleventh base electrode. The third external electrode 29c may cover the third base electrode 28c and the eleventh base electrode.

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

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

[0136] The fifth external electrode 29e and the seventh external electrode 29g are located from the second side surface 34b over at least the first surface 32a and are connected to a plurality of first internal electrodes 30a. The fifth external electrode 29e and the seventh external electrode 29g are respectively connected to a fifth base electrode 28e and a seventh base electrode 28g. The fifth external electrode 29e and the seventh external electrode 29g may respectively cover the fifth base electrode 28e and the seventh base electrode 28g. The fifth external electrode 29e is located from the second side surface 34b over the first surface 32a and the second surface 32b and may be connected to the fifth base electrode 28e and the thirteenth base electrode. The fifth external electrode 29e may cover the fifth base electrode 28e and the thirteenth base electrode. The seventh external electrode 29g is located from the second side surface 34b over the first surface 32a and the second surface 32b and may be connected to the seventh base electrode 28g and the fifteenth base electrode. The seventh external electrode 29g may cover the seventh base electrode 28g and the fifteenth base 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 a plurality of first internal electrodes 30a or a plurality of second internal electrodes 30b. The second portion 292 is located on the first main surface 32a and is connected to any one of the first underlying electrodes 28a to the eighth underlying electrodes 28h. The second portion 292 may cover any one of the first underlying electrodes 28a to the eighth underlying electrodes 28h. The second portion 292 is further located on the second main surface 32b and may be connected to any one of the ninth underlying electrode to the sixteenth underlying electrode. The second portion 292 may cover any one of the ninth underlying electrode to the sixteenth underlying electrode. The first portion 291 is also referred to as an end face electrode portion, and the second portion 292 is also referred to as a main surface electrode portion.

[0138] Hereinafter, the configurations of the end face electrode portion 291 and the main surface electrode portion 292 of the multilayer ceramic capacitors 10B and 10C will be described. Regarding the description of the configurations of the end face electrode portion 41 and the main surface electrode portion 42 of the multilayer ceramic capacitor 10, it may be applied to the multilayer ceramic capacitors 10B and 10C as long as there is no contradiction. For the sake of caution, it will be briefly described below.

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

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

[0141] The underlying electrode 28 and the internal electrode 30 may mainly contain Ni, and the external electrode 29 may mainly contain Cu.

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

[0143] The average particle size of the metal particles M contained in the end face 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] In the end face electrode portion 291, as it approaches the laminate 27, the particle size of the metal particles M contained in the end face electrode portion 291 may become smaller.

[0145] In the main surface electrode portion 292, as it approaches the laminate 27, the particle size of the metal particles M contained in the main surface electrode portion 292 may become larger.

[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 such that the average particle size of the metal particles at the position S, which is separated from the surface of the laminate 27 by a predetermined distance L' on the side opposite to the surface of the laminate 27 side in the base electrode 28, is larger than the average particle size of the metal particles at the position R, which is separated from the surface of the laminate 27 by the predetermined distance L' in the internal electrode 30 (see FIGS. 5 and 6). The predetermined distance L' may be, for example, 0.5 to 1.5 μm, or may be 1 μm.

[0148] Although not particularly illustrated, further embodiments will be described. For convenience, in the following description, reference numerals of any of the first to fourth embodiments may be used. The following description may be applied to embodiments other than the embodiments referred to by the reference numerals as long as there is no contradiction.

[0149] The underlying electrode 13 may be embedded in the laminate 12 (more specifically, the cover portions 12b and 12c) while exposing the upper surface or the lower surface to the outside of the laminate 12. In other words, the underlying 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 planar and may be recessed at the position of the underlying electrode 13. For the sake of convenience, attention is paid to the underlying electrode 13 on the upper surface side of the laminate 12. The upper surface of the embedded underlying electrode 13 may be flush with or located above the non-arrangement region of the underlying electrode 13 on the first surface 17a.

[0150] Note that even when the underlying electrode 13 is embedded as described above, the underlying 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 underlying electrode 13 is arranged is a part of the first surface 17a or the second surface 17b.

[0151] The method for manufacturing the embedded type underlying electrode 13 as described above is arbitrary. For example, taking the upper surface side as an example, the cover portion 12b is made of two layers of ceramic green sheets. The underlying electrode 13 precursor is printed on the lower layer ceramic green sheet. A notch in which the underlying electrode 13 is located is formed in the upper layer ceramic green sheet. Thereby, the embedded type underlying electrode 13 is manufactured. And / or, the underlying electrode 13 precursor may be sunk into the ceramic green sheet by pressing.

[0152] The capacitor may have an exterior resin covering the entire structure exemplified in FIG. 1 and the like, and a lead wire connected to the external electrode and extending from the exterior resin. From another perspective, the capacitor may not be a surface mount type but a through-hole mount type.

[0153] Rather than being alternately stacked one by one, the two types of internal electrodes connected to different external electrodes may be alternately stacked two by two. 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 made 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 plurality of dielectric layers do not necessarily have the same shape and size as each other.

[0154] Also, the two types of internal electrodes connected to different external electrodes do not necessarily face each other. For example, two types of internal electrodes connected to different external electrodes are provided in the same layer, and by providing internal electrodes facing the two types of internal electrodes, a circuit in which two parallel plate capacitors are connected in series may be configured. Also, a circuit in which three or more parallel plate capacitors are connected in series may be configured.

[0155] In the first embodiment, the internal electrode 5 fits within the width (y direction) of the dielectric layer 6, thereby not being exposed from the side surfaces 9a, 9b of the laminate 2. However, a configuration for preventing the internal electrode 5 from being exposed may also be realized by overlaying a dielectric layer on the side surfaces 9a, 9b. From another perspective, the base component 1 does not necessarily have an overall laminated structure.

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

[0157] (1) A laminate including a plurality of internal electrodes and a plurality of dielectric layers alternately laminated, having a first surface and a second surface facing each other in the lamination direction, a first end surface and a second end surface facing each other in a length direction orthogonal to the lamination direction, and a first side surface and a second side surface facing each other in a width direction orthogonal to the lamination direction and the length direction, a plurality of base electrodes, a plurality of external electrodes, and 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 positioned closer to the first end face on the first surface and a second base electrode positioned closer to the second end face on the first surface. The plurality of external electrodes include a first external electrode positioned from the first end face over at least the first surface and connected to the plurality of first internal electrodes and the first base electrode, and a second external electrode positioned from the second end face over 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. A multilayer electronic component in which an average particle diameter of metal particles included in the first portion is smaller than an average particle diameter of metal particles included in the second portion.

[0158] (2) A laminate including a plurality of internal electrodes and a plurality of dielectric layers alternately laminated, having a first surface and a second surface facing each other in a lamination direction, a first side surface and a second side surface facing each other in a length direction orthogonal to the lamination direction, and a third side surface and a fourth side surface facing each other in a width direction orthogonal to the lamination direction and the length direction, a plurality of base electrodes, and a plurality of external electrodes, wherein the plurality of internal electrodes include a plurality of first internal electrodes exposed at a first corner portion from the first side surface to the third side surface and a second corner portion from the second side surface to the fourth side surface, and a plurality of second internal electrodes exposed at a third corner portion from the first side surface to the fourth side surface and a fourth corner portion from the second side surface to the third side surface. The plurality of base electrodes include a first base electrode positioned closer to the first corner portion on the first surface, and a second base electrode positioned closer to the second corner portion on the first surface. a third base electrode located near the third corner portion on the first surface; a fourth base electrode located near the fourth corner portion on the first surface, and having: The plurality of external electrodes include: a first external electrode located from the first corner portion over 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 over 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 over 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 over at least the first surface and connected to the plurality of second internal electrodes and the fourth base electrode, and having: 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 one of the first base electrode, the second base electrode, the third base electrode, and the fourth base electrode; a multilayer electronic component in which an average particle diameter of metal particles included in the first portion is smaller than an average particle diameter of metal particles included in the second portion.

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

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

[0161] (5) The average particle size of the metal particles at a position separated by a predetermined distance in the length direction from the surface on the laminate side in the first part is smaller than the average particle size of the metal particles at a position separated by the predetermined distance in the lamination direction from the surface on the laminate side in the second part. The laminated electronic component according to any one of (1) to (4) above.

[0162] (6) The average particle size of the metal particles contained in the second part is 1.1 times or more and 2.7 times or less the average particle size of the metal particles contained in the first part. The laminated electronic component according to any one of (1) to (5) above.

[0163] (7) In the first part, as it approaches the laminate, the particle size of the metal particles contained in the first part becomes smaller. The laminated electronic component according to (1) to (6) above.

[0164] (8) In the second part, as it approaches the laminate, the particle size of the metal particles contained in the second part becomes larger. The laminated electronic component according to (1) to (7) above.

[0165] (9) 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. The laminated electronic component according to (1) to (8) above.

[0166] (10) The average particle size of the metal particles at a position separated by a predetermined distance in the lamination direction from the surface opposite to the surface on the laminate side in the plurality of base electrodes is larger than the average particle size of the metal particles at a position separated by the predetermined distance in the length direction from the surface of the laminate in the plurality of internal electrodes. The laminated electronic component according to any one of (1) to (9) above.

[0167] (11) The dimension in the lamination direction is smaller than the dimension in the length direction and smaller than the dimension in the width direction. The laminated electronic component according to any one of (1) to (10) above.

Explanation of Reference Numerals

[0168] 10, 10A, 10B, 10C... multilayer electronic component (multilayer ceramic capacitor), 1... body component, 1p... body component precursor, 2... laminate, 2a... capacitance forming part, 2b, 2c... cover part, 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 (end face electrode part), 42... second part (main face electrode part), 5... internal electrode, 5a... first internal electrode, 5b... second internal electrode, 6... dielectric layer, 7a... first face, 7b... second face, 8a... first end face, 8b... second end face, 9a... first side face, 9b... second side face, 11... body component, 12... laminate, 12a... capacitance forming part, 12b, 12c... cover part, 13... base electrode, 13a... first base electrode, 13b... second base electrode, 13c... third base electrode, 13d... fourth base electrode, 13e... fifth base electrode, 13f... sixth base electrode, 13g... seventh base electrode, 13h... eighth base electrode, 14... external electrode, 14a... first external electrode, 14b... second external electrode, 14c... third external electrode, 14d... fourth external electrode, 141... first part (end face electrode part), 142... second part (main face electrode part), 15... internal electrode, 15a... first internal electrode, 15b... second internal electrode, 16... dielectric layer, 17a... first face, 17b... second face, 18a... first side face, 18b... second side face, 18c... third side face, 18d... fourth side face, 19a... first corner, 19b... second corner, 19c... third corner, 19d... fourth corner, 21... ceramic green sheet, 22... internal electrode sheet, 23... base electrode sheet, 24... mother laminate, 25... planned cutting line, 26... body component, 27... laminate, 27a... capacitance forming part, 27b,27c…Cover part, 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 part (end face electrode part), 292…Second part (main face electrode part), 30…Internal electrode, 30a…First internal electrode, 30b…Second internal electrode, 31…Dielectric layer, 32a…First face, 32b…Second face, 33a…First end face, 33b…Second end face, 34a…First side face, 34b…Second side face.,

Claims

1. A laminate having a plurality of internal electrodes and a plurality of dielectric layers stacked alternately, having a first surface and a second surface facing each other in the stacking direction, and a wall surface facing a predetermined direction intersecting the stacking direction, Multiple base electrodes, Includes multiple external electrodes, The plurality of external electrodes include a first external electrode that extends from the wall surface to at least the first surface, The first external electrode is, A first portion of the plurality of internal electrodes connected to the internal electrode exposed on the wall surface, It has a second portion connected to the base electrode located on the first surface among the plurality of base electrodes, A multilayer electronic component in which the average particle size of the metal particles contained in the first part is smaller than the average particle size of the metal particles contained in the second part.

2. The first external electrode is a plating layer. The stacked electronic component according to claim 1.

3. The internal electrode to which the first external electrode is connected is mainly composed of Ni, and the first external electrode is mainly composed of Cu. The stacked electronic component according to claim 1.

4. In the first portion, the average particle size of the metal particles at a position separated by a predetermined distance in the predetermined direction from the surface on the laminate side is smaller than the average particle size of the metal particles at a position separated by a predetermined distance in the laminate direction from the surface on the laminate side in the second portion. The stacked electronic component according to claim 1.

5. The average particle size of the metal particles included in the second part is 1.1 times or more and 2.7 times or less the average particle size of the metal particles included in the first part. The stacked electronic component according to claim 1.

6. The first portion has a decreasing particle size of the metal particles contained in it as it approaches the laminate. The stacked electronic component according to claim 1.

7. In the second portion, the particle size of the metal particles contained in the second portion increases as it approaches the laminate. The stacked electronic component according to claim 1.

8. The average particle size of the metal particles contained in the base electrode to which the first base electrode is connected is greater than the average particle size of the metal particles contained in the internal electrode to which the first base electrode is connected. The stacked electronic component according to claim 1.

9. The average particle size of metal particles in the first base electrode at a position separated by a predetermined distance in the lamination direction from the surface opposite to the laminate side is greater than the average particle size of metal particles in the internal electrode to which the first base electrode is connected at a position separated by the predetermined distance in the longitudinal direction from the surface of the laminate. The stacked electronic component according to claim 1.

10. The dimension in the stacking direction is smaller than the dimension in the length direction and smaller than the dimension in the width direction. The stacked electronic component according to claim 1.

11. The laminate has a first side surface and a second side surface that face each other in the length direction perpendicular to the stacking direction, and a third side surface and a fourth side surface that face each other in the width direction perpendicular to the stacking direction and the length direction. The aforementioned plurality of internal electrodes are Multiple first internal electrodes exposed at the first corner portion extending from the first side to the third side, and at the second corner portion extending from the second side to the fourth side, It has a plurality of second internal electrodes exposed in the third corner portion extending from the first side to the fourth side portion, and in the fourth corner portion extending from the second side to the third side portion, The aforementioned multiple base electrodes are A first base electrode located near the first corner of the first surface, A second base electrode located near the second corner of the first surface, A third base electrode located near the third corner on the first surface, The first surface has a fourth base electrode located near the fourth corner, The aforementioned plurality of external electrodes are The first external electrode is located at least across the first surface from the first corner and is connected to the plurality of first internal electrodes and the first base electrode, A second external electrode is located extending from the second corner portion across at least the first surface and is connected to the plurality of first internal electrodes and the second base electrode, A third external electrode is located extending from the third corner portion across at least the first surface and is connected to the plurality of second internal electrodes and the third base electrode, It has a fourth external electrode that extends from the fourth corner and across at least the first surface, and is connected to the plurality of second internal electrodes and the fourth base electrode, The first external electrode, the second external electrode, the third external electrode, and the fourth external electrode each have 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 average particle size of the metal particles contained in the first part is smaller than the average particle size of the metal particles contained in the second part. The stacked electronic component according to claim 1.

12. The laminate has a first end face and a second end face that face each other in the length direction perpendicular to the stacking direction, and a first side face and a second side face that face each other in the width direction perpendicular to the stacking direction and the length direction. The plurality of internal electrodes comprises a plurality of first internal electrodes exposed on the first end face and a plurality of second internal electrodes exposed on the second end face. The plurality of base electrodes include a first base electrode located near the first end face on the first surface, and a second base electrode located near the second end face on the first surface. The aforementioned plurality of external electrodes are The first external electrode is located from the first end face, extending at least across the first surface, and is connected to the plurality of first internal electrodes and the first base electrode, It has a second external electrode that extends from the second end face to at least the first face and is connected to the plurality of second internal electrodes and the second base electrode, The first external electrode and the second external electrode each have 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 average particle size of the metal particles contained in the first part is smaller than the average particle size of the metal particles contained in the second part. The stacked electronic component according to claim 1.

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