Multilayer ceramic electronic component and method for manufacturing same

Abstract

This multilayer ceramic electronic component is provided with: a capacity formation part in which dielectric layers and internal electrodes are alternately laminated along a first axial direction and which has a pair of main surfaces facing each other along the first axial direction, a pair of side surfaces on which the internal electrodes are exposed and which face each other in a second axial direction orthogonal to the first axial direction, and a pair of end surfaces which face each other in a third axial direction orthogonal to the first axial direction and the second axial direction; a protection layer that covers the capacity formation part with the main surfaces and the side surfaces as interfaces; particles that are present across the capacity formation part and the protection layer and have the ratio of a short side to a long side of 1 / 3 or less, the long side being the longest portion in a cross section including a direction along the first axial direction, and the short side being the longest portion among the portions orthogonal to the long side; and a pair of external electrodes and covers at least the end surfaces, respectively.

Description

Multilayer ceramic electronic component and its manufacturing method

[0001] The present invention relates to a multilayer ceramic electronic component and a method for manufacturing the same.

[0002] Recently, multilayer ceramic electronic components have been known that have a capacitance-forming portion formed by alternating internal electrode layers and dielectric layers, and that have side margins formed on the sides of the capacitance-forming portion. Such multilayer ceramic electronic components are increasingly being built with multiple layers. As the number of layers increases, it is thought that misalignment may occur during stacking of green sheets, making it difficult to maintain the rectangularity of the chip. To address this issue, a conventional method has been to form side margins by attaching ceramic green sheets to the sides of the capacitance-forming portion. In this method, the capacitance-forming portion is obtained by cutting the stacked green sheets into individual pieces, which makes it easier to maintain the rectangularity of the chip. However, the side margins formed by the attachment may peel off. Therefore, various proposals have been made to prevent peeling of the side margins (see, for example, Patent Document 1).

[0003] JP 2019-106528 A

[0004] In order to prevent peeling of the side margins, it is conceivable to increase the amount of organic binder in the green sheets to improve adhesion of the side margins. However, increasing the amount of organic binder can lead to poorer binder removal properties and higher firing temperatures. Poorer binder removal properties increase the time required for binder removal. Furthermore, higher firing temperatures can lead to concerns about the deterioration of the electrical properties of the multilayer ceramic electronic component, such as the spheroidization of the internal electrodes and a decrease in the continuity ratio of the internal electrodes. Such problems can also occur in Patent Document 1.

[0005] Therefore, an object of the present invention is to ensure good binder removal properties while suppressing peeling mainly in the side margin portions of a multilayer ceramic electronic component.

[0006] In order to solve the above-described problems, the multilayer ceramic electronic component disclosed in this specification includes a capacitance forming portion in which dielectric layers and internal electrodes are alternately stacked along a first axial direction, the capacitance forming portion having a pair of main surfaces opposing each other along the first axial direction, a pair of side surfaces opposing each other in a second axial direction orthogonal to the first axial direction and from which the internal electrodes are exposed, and a pair of end surfaces opposing each other in a third axial direction orthogonal to the first and second axial directions; a protective layer covering the capacitance forming portion with the main surfaces and the side surfaces as interfaces; particles present across the capacitance forming portion and the protective layer, the particles having a ratio of the short side to the long side being 1 / 3 or less when the longest part in a cross section including a direction along the first axial direction is defined as the long side and the longest part of the part orthogonal to the long side is defined as the short side; and a pair of external electrodes covering at least the end faces, respectively.

[0007] In the multilayer ceramic electronic component having the above configuration, the protective layer may include a side margin portion that covers the side surface from a direction along the second axial direction, and the particles may be present across the capacitance forming portion and the side margin portion via the side surface that forms the interface between the capacitance forming portion and the side margin portion.

[0008] Furthermore, in the multilayer ceramic electronic component having the above configuration, the capacitance forming portion is included in the protective layer and forms a laminated portion together with a cover portion laminated along the first axial direction, and the particles can be present across the capacitance forming portion and the cover portion via a main surface of the capacitance forming portion which forms the interface between the capacitance forming portion and the cover portion.

[0009] In the multilayer ceramic electronic component having the above configuration, the particles may contain any of Si, Al, Mn, Mg, Zn, and a rare earth element.

[0010] Furthermore, in the multilayer ceramic electronic component having the above configuration, the particles may contain either C or Ag.

[0011] In the multilayer ceramic electronic component having the above configuration, when the first axis direction is defined as a height direction, the second axis direction orthogonal to the first axis direction is defined as a width direction, and the third axis direction orthogonal to the first axis direction and the second axis direction is defined as a length direction, the height dimension of the multilayer ceramic electronic component can be 1.3 times or more the width dimension or length dimension of the multilayer ceramic electronic component.

[0012] In the multilayer ceramic electronic component having the above-described configuration, the grains may have an inclination angle of 45 degrees or less with respect to the normal to the interface.

[0013] Furthermore, in the multilayer ceramic electronic component having the above-described configuration, the proportion of the particles having the inclination angle of 45 degrees or less may be 80% or more.

[0014] In the multilayer ceramic electronic component having the above configuration, the ratio of the size of the particles to the size of the particles forming the protective layer may be 0.8 to 2.0 times.

[0015] In the multilayer ceramic electronic component having the above-described configuration, the frequency of the particles is 0.25 particles / μm ２ 1 piece / μm or more ２ The embodiment may be:

[0016] Furthermore, in the multilayer ceramic electronic component having the above configuration, the ratio of the size of the portion of the particles located within the capacitance forming portion to the size of the portion of the particles located within the side margin portion may be in the range of 1:3 to 3:1.

[0017] Furthermore, in the multilayer ceramic electronic component having the above configuration, the ratio of the size of the portion of the particles located within the capacitance forming portion to the size of the portion of the particles located within the cover portion can be in the range of 1:3 to 3:1.

[0018] The method for manufacturing a multilayer ceramic electronic component disclosed in this specification can be implemented as an embodiment including the steps of: forming an unsintered laminated portion in which dielectric layers and internal electrodes are alternately stacked along a first axial direction, the unsintered laminated portion having a pair of main surfaces opposing each other along the first axial direction, a pair of side surfaces opposing each other in a second axial direction orthogonal to the first axial direction and from which the internal electrodes are exposed, and a pair of end surfaces opposing each other in a third axial direction orthogonal to the first and second axial directions, the unsintered laminated portion having the internal electrodes extended to each of the pair of end surfaces; spraying particles having a ratio of short sides to long sides of 1 / 3 or less onto the side surfaces; and attaching ceramic sheets that form side margin portions to the side surfaces onto which the particles have been sprayed.

[0019] The method for manufacturing a multilayer ceramic electronic component having the above configuration can be embodied as including a step of vibrating the unsintered laminated portion and removing excess particles from the side surface, the step being carried out after the step of spraying the particles.

[0020] In the method for manufacturing a monolithic ceramic electronic component having the above-described configuration, the step of blowing the particles may be such that the side surface is inclined with respect to the direction in which the particles are blown.

[0021] In the method for manufacturing a multilayer ceramic electronic component having the above configuration, the step of spraying the particles can be configured such that the particles are sprayed onto the side surfaces while the unsintered laminated portion is being heated.

[0022] Furthermore, in the method for manufacturing a multilayer ceramic electronic component having the above configuration, in the step of attaching the ceramic sheets that form the side margin portions, the ceramic sheets can be pressed against the side surfaces while being heated.

[0023] In the method for manufacturing a multilayer ceramic electronic component having the above-described configuration, the ceramic sheets forming the side margin portions may be pressed and attached.

[0024] Furthermore, in the method for manufacturing a multilayer ceramic electronic component having the above-described configuration, the step of forming the unsintered laminated portion can include a step of spraying particles having a ratio of short sides to long sides of 1 / 3 or less onto a surface facing the first axial direction of a laminate in which ceramic sheets having unsintered internal electrodes formed thereon are stacked along the first axial direction, and a step of stacking a ceramic sheet that forms a cover portion onto the surface onto which the particles have been sprayed.

[0025] According to the invention disclosed in this specification, in a multilayer ceramic electronic component, peeling can be suppressed mainly in the side margin portions, while good binder removal properties can be ensured.

[0026] Fig. 1 is a perspective view of a multilayer ceramic capacitor according to an embodiment. Fig. 2(A) is a cross-sectional view taken along line A1-A1 in Fig. 1, Fig. 2(B) is a schematic diagram showing an enlarged view of portion S1 in Fig. 2(A), and Fig. 2(C) is a schematic diagram showing an enlarged view of portion S2 in Fig. 2(A). Fig. 3 is a cross-sectional view taken along line A2-A2 in Fig. 1. Fig. 4(A) is a diagram showing the short and long sides of a first particle, Figs. 4(B-1) and 4(B-2) are explanatory diagrams showing the inclination angle α of the first particle with respect to the normal to the interface, and Fig. 4(C) is an explanatory diagram showing a state in which the first particle is arranged along the normal to the interface. FIG. 5A is a conceptual diagram showing how an organic component passes through the first particles at the interface between the laminate portion and the side margin portion. FIG. 5B is a conceptual diagram showing how the amount of first particles is increased from the amount of first particles shown in FIG. 5A . FIG. 5C is a conceptual diagram showing how the amount of first particles is increased from the amount of first particles shown in FIG. 5B . FIG. 6 is a flowchart showing an example of a method for manufacturing a multilayer ceramic capacitor according to an embodiment. FIG. 7 is a perspective view showing some steps included in the method for manufacturing a multilayer ceramic capacitor according to an embodiment. FIG. 8 is an explanatory diagram showing how the first particles are sprayed onto the main surface of the capacitance forming portion. FIGS. 9A to 9D are explanatory diagrams showing some steps included in the method for manufacturing a multilayer ceramic capacitor according to an embodiment. FIG. 10 is a plan view showing a cutting step included in the method for manufacturing a multilayer ceramic capacitor according to an embodiment. Fig. 11(A) is a perspective view of an unfired laminated part created by cutting a laminated sheet on which a cover part has been laminated, Fig. 11(B) is an explanatory diagram showing a schematic diagram of a state in which first particles are sprayed onto the side surface of the unfired laminated part, and Fig. 12 is an explanatory diagram showing a schematic diagram of a state in which a green sheet forming a side margin part is attached to the side surface of the unfired laminated part onto which the first particles have been sprayed.

[0027] Hereinafter, a circuit board according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, the dimensions, ratios, etc. of each part may not be illustrated to be exactly the same as the actual ones. Furthermore, for convenience of illustration, some details or components may be omitted in some drawings. In the drawings, mutually orthogonal X-axis, Y-axis, and Z-axis are appropriately shown. In the following description, the Z-axis direction corresponds to the first axis direction, the Y-axis direction corresponds to the second axis direction, and the X-axis direction corresponds to the third axis direction.

[0028] (Embodiment) [Configuration of Multilayer Ceramic Capacitor] First, with reference to FIGS. 1 to 5C, a multilayer ceramic capacitor (MLCC: Multi Layered Ceramic Capacitor) 10 of an embodiment will be described. FIG. 1 is a perspective view of the multilayer ceramic capacitor 10 of the embodiment. FIG. 2A is a cross-sectional view taken along line A1-A1 in FIG. 1, FIG. 2B is a schematic view showing an enlarged view of portion S1 in FIG. 2A, and FIG. 2C is a schematic view showing an enlarged view of portion S2 in FIG. 2A. FIG. 3 is a cross-sectional view taken along line A2-A2 in FIG. 1. FIG. 4A is a view showing the short and long sides of a first particle 32 (34). 4(B-1) and 4(B-2) are explanatory diagrams showing the inclination angle α of the first particles 32 with respect to the perpendicular line NL1 of the side surface S20 of the laminate portion 20, which is the interface between the laminate portion 20 and the side margin portion 18, and FIG. 4(C) is an explanatory diagram schematically showing a state in which the first particles 34 are provided along the perpendicular line NL1 direction of the interface. FIG. 5(A) is a conceptual diagram schematically showing the state in which the organic component passes between the first particles 32 at the interface between the laminate portion 20 and the side margin portion 18, FIG. 5(B) is a conceptual diagram schematically showing the state when the amount of the first particles 32 is increased from the amount of the first particles 32 shown in FIG. 5(A), and FIG. 5(C) is a conceptual diagram schematically showing the state in which the amount of the first particles 32 is further increased from the amount of the first particles 32 shown in FIG. 5(B). The multilayer ceramic capacitor 10 has an X-axis direction as its length direction, a Y-axis direction as its width direction, and a Z-axis direction as its height direction.

[0029] The multilayer ceramic capacitor 10 includes a ceramic body 11, a first external electrode 14 provided at one end in the longitudinal direction of the multilayer ceramic capacitor 10, and a second external electrode 15 provided at the other end.

[0030] The ceramic body 11 is configured as a hexahedron having first and second main surfaces M11, M12 orthogonal to the Z axis, first and second end faces E11, E12 orthogonal to the X axis, and first and second side surfaces S11, S12 orthogonal to the Y axis. Note that the term "hexahedron" refers to any shape that is substantially hexahedral, and for example, the edges connecting the faces of the ceramic body 11 may be rounded.

[0031] The main surfaces M11, M12, end surfaces E11, E12, and side surfaces S11, S12 of the ceramic body 11 are all flat surfaces. According to this embodiment, the flat surfaces do not necessarily have to be strictly planar as long as they are recognized as flat when viewed overall, and include, for example, surfaces with minute irregularities or gently curved shapes within a predetermined range.

[0032] The multilayer ceramic capacitor 10 of this embodiment is a tall type, with a height T

[10] that is 1.3 times or more the width W

[10] . In the multilayer ceramic capacitor 10, a large capacitance is achieved by increasing the height [T10]. It is desirable that the height T

[10] be 1.5 times or more the width W

[10] . The height T

[10] can be, for example, 1.6 times or 1.7 times the width W

[10] , or even higher. This allows the capacitance of the first multilayer ceramic capacitor 10 to be further increased.

[0033] In addition, in this embodiment, the condition for the height T

[10] is defined by the ratio to the width W

[10] , but the condition for the height T

[10] may be set based on the relationship with the length L

[10] instead of the width W

[10] . That is, the first multilayer ceramic capacitor 10 may be a tall type in which the height T

[10] is 1.3 times or more the length W

[10] . Also, the height T

[10] may be 1.5 times or more the length L

[10] .

[0034] However, the size of the multilayer ceramic capacitor 10 does not necessarily have to have such a dimensional relationship. For example, the design values ​​can be selected from any one of the following: length 0.25 mm, width 0.125 mm, height 0.125 mm (0201 size), length 0.4 mm, width 0.2 mm, height 0.2 mm (0402 size), length 0.6 mm, width 0.3 mm, height 0.3 mm (0603 size), length 1.0 mm, width 0.5 mm, height 0.5 mm (1005 size), length 3.2 mm, width 1.6 mm, height 1.6 mm (3216 size), length 4.5 mm, width 3.2 mm, height 2.5 mm (4532 size), or length 5.7 mm, width 5.0 mm, height 2.3 mm (5750 size). Note that the above sizes may include a dimensional tolerance of ±5 to 30%.

[0035] The ceramic body 11 has a laminated portion 20 and a pair of side margin portions 18. The laminated portion 20 has a capacitance forming portion 16 and a pair of cover portions 17. The capacitance forming portion 16 includes a plurality of first internal electrodes 12 and second internal electrodes 13 that are alternately laminated with a plurality of dielectric layers 19 along the Z-axis direction. In this embodiment, the first internal electrodes 12, second internal electrodes 13, and dielectric layers 19 are each configured in a sheet shape extending along the X-Y plane. Note that the number of layers of the first and second internal electrodes 12, 13 in each drawing does not represent the actual number of layers.

[0036] The internal electrodes 12, 13 are alternately arranged along the Z-axis direction so as to face each other in the Z-axis direction. The internal electrodes 12, 13 face each other in the Z-axis direction in a facing region in the center of the X-axis direction and the Y-axis direction. The first internal electrode 12 corresponds to a first group, is drawn from the facing region to one end face E11, and is connected to the first external electrode 14. The second internal electrode 13 corresponds to a second group, is drawn from the facing region to the other end face E12, and is connected to the second external electrode 15.

[0037] The internal electrodes 12, 13 contain a metal material as a main component, typically nickel (Ni), but also copper (Cu), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), and alloys thereof.

[0038] With this configuration, when a voltage is applied between the external electrodes 14 and 15 in the multilayer ceramic capacitor 10, the voltage is applied to the plurality of dielectric layers 19 between the internal electrodes 12 and 13 in the opposing regions. As a result, a charge corresponding to the voltage between the external electrodes 14 and 15 is stored in the multilayer ceramic capacitor 10.

[0039] In the laminated portion 20, a dielectric ceramic having a high dielectric constant is used to increase the capacitance of each dielectric layer 19 between the first and second internal electrodes 12, 13. As the dielectric ceramic having a high dielectric constant, for example, barium titanate (BaTiO ３ Examples of suitable perovskite materials include materials with a perovskite structure containing barium (Ba) and titanium (Ti), such as ZnO, ZnO, and ZnO.

[0040] The dielectric ceramic is strontium titanate (SrTiO ３ ), calcium titanate (CaTiO ３ ), magnesium titanate (MgTiO ３ ), calcium zirconate (CaZrO ３ ), calcium zirconate titanate (Ca(Zr,Ti)O ３ ), barium calcium zirconate titanate ((Ba,Ca)(Zr,Ti)O ３ ), barium zirconate (BaZrO ３ ), titanium oxide (TiO ２ ) or other composition systems may also be used.

[0041] The pair of cover portions 17 cover the capacitance forming portion 16 from both sides in the Z-axis direction, which is the stacking direction. That is, as shown in FIG. 2A, the cover portion 17 is stacked on the main surface M16 of the capacitance forming portion 16 (hereinafter referred to as the "capacitance forming portion main surface"). The cover portion 17 is part of the protective layer in the height direction. The cover portion 17 is formed, for example, by a laminate of ceramic sheets extending along the X-Y plane. From the viewpoint of suppressing internal stress, it is preferable that the dielectric ceramic forming the cover portion 17 has the same main component composition as the dielectric layer 19.

[0042] 2C, the capacitance forming portion main surface M16 facing the Z-axis direction forms the interface between the capacitance forming portion 16 and the cover portion 17. On the capacitance forming portion main surface M16, first particles 34 are present straddling the capacitance forming portion 16 and the cover portion 17. These first particles 34 may be the same as the first particles 32 described later.

[0043] A pair of side margins 18 are formed along the Z-axis direction and cover the laminated portion 20 from the Y-axis direction. As shown in FIG. 2A , the side margins 18 are provided to cover the side surfaces S20 of the laminated portion 20 (hereinafter referred to as "laminated portion side surfaces"). The side margins 18 are part of the protective layer. In the region where the capacitance forming portion 16 is formed, the laminated portion side surfaces S20 also serve as the side surfaces S16 (hereinafter referred to as "capacitance forming portion side surfaces") of the capacitance forming portion 16 (see FIG. 5A , etc.). Therefore, by covering the laminated portion side surfaces S20, the side margins 18 also cover the capacitance forming portion side surfaces S16. The side margins 18 are formed on the laminated portion side surfaces S20 perpendicular to the Y-axis. From the viewpoint of suppressing internal stress, etc., it is preferable that the dielectric ceramic constituting the side margins 18 has the same main component as the dielectric layer 19.

[0044] 2(B), the stacked portion side surface S20 facing the Y-axis direction forms an interface between the stacked portion 20 and the side margin portion 18. On the stacked portion side surface S20, first particles 32 are present across the stacked portion 20 and the side margin portion 18. The first particles 32 will be described in detail later.

[0045] 3, the first external electrode 14 covers the first end face E11 of the ceramic body 11 and extends to four surfaces located around the first end face E11. That is, the first external electrode 14 extends to a pair of main faces M11, M12. Although not shown, the first external electrode 14 also extends to a pair of side faces S11, S12 (see FIG. 2A).

[0046] 3, the second external electrode 15 covers the second end face E12 of the ceramic body 11 and extends to four surfaces located around the second end face E12. That is, the second external electrode 15 extends to a pair of main faces M11, M12. Although not shown, the second external electrode 15 also extends to a pair of side faces S11, S12 (see FIG. 2A).

[0047] In the external electrodes 14, 15, both the cross section parallel to the XZ plane and the cross section parallel to the XY plane are U-shaped. The shapes of the external electrodes 14, 15 are not limited to the examples shown in the drawings.

[0048] The external electrodes 14, 15 contain a metal material as a main component. Examples of the metal material constituting the external electrodes 14, 15 include copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), and alloys thereof. In this embodiment, the term "main component" refers to the component with the highest content.

[0049] <Regarding the First Particles 32, 34> The first particles 32, 34 will now be described in detail. As shown in FIG. 2B , the first particles 32 are arranged at the interface between the multilayer portion 20 and the side margin portion 18, i.e., on the side surface S20 of the multilayer portion 20. The first particles 32 can strengthen the bonding strength between the multilayer portion 20 and the side margin portion 18. The multilayer ceramic capacitor 10 of this embodiment is a so-called tall type, and the bonding area of ​​the side margin portion 18 is large. By arranging the first particles 32, peeling of the side margin portion 18 can be suppressed even in a tall multilayer ceramic capacitor 10. As shown in FIG. 2C , the first particles 34 are arranged at the interface between the capacitance forming portion 16 and the cover portion 17, i.e., on the main surface M16 of the capacitance forming portion 16. The first particles 34 can strengthen the bonding strength between the capacitance forming portion 16 and the cover portion 17.

[0050] In this embodiment, the first particles 34 are disposed at the interface between the capacitance forming portion 16 and the cover portion 17, but it is sufficient that the first particles 32 are disposed at least at the interface between the laminate portion 20 and the side margin portion 18. With reference to Fig. 3, the first particles 32 disposed at the interface between the laminate portion 20 and the side margin portion 18 are distributed throughout the entire laminate portion 20, including the cover portion 17, when the laminate portion 20 is viewed along the Y-axis direction. Although not shown, the first particles 34 disposed at the interface between the capacitance forming portion 16 and the cover portion 17 are distributed throughout the entire capacitance forming portion 16 when the capacitance forming portion 16 is viewed along the Z-axis direction.

[0051] <Ratio of Short Side to Long Side of First Particle> The first particles 32, 34 are described in detail below. A first particle 32 will be described when the first particles 32 and the first particles 34 share common properties. Referring to FIG. 4A , the first particles 32 have a needle-like shape with pointed ends. The ratio of the length a of the short side to the length b of the long side of the first particles 32, i.e., the aspect ratio (a:b), is 1 / 3 or less. The aspect ratio can be, for example, 0.3 or 0.2. As described later, the first particles 32 are sprayed toward the main surface M16 and the side surface S20, which form the interface, during the manufacturing process of the multilayer ceramic capacitor 10. The first particles 32 are then stuck into the main surface M16 and the side surface S20. Furthermore, a cover portion 17 and a side margin portion 18 are provided on the main surface M16 and the side surface S20 where the first particles 32 have stuck. At this time, the other end of the first particle 32 penetrates the cover portion 17 or the side margin portion 18. The first particle 32 has a shape with a predetermined aspect ratio, so that it can penetrate both of the predetermined joining objects. The multilayer ceramic capacitor 10 discharges organic components contained in the binder during its manufacturing process. At this time, if the first particle 32 has a shape with a predetermined aspect ratio, it is thought that the efficiency of discharging the organic components can be improved. This will also be described in detail later.

[0052] <Composition of First Particles> The first particles 32 can be formed from Si-Al glass. Si-Al glass particles can contain any of Si (silicon), Al (aluminum), Mn (manganese), Mg (magnesium), Zn (zinc), and rare earth elements. The first particles 32 can be particles formed from a single element or a compound of these elements. Compound particles can appropriately contain the above elements. Forming the first particles 32 from Si-Al glass can improve the moisture resistance of the multilayer ceramic capacitor 10. These materials are selected as they can improve moisture resistance and function as sintering aids, etc. The addition of Al facilitates the formation of a crystal shape with a large aspect ratio.

[0053] The first particles 32 may include particles formed of either C (carbon) or Ag (silver). That is, each particle may be formed of a single element, C, or a single element, Ag. However, for example, particles formed of C and particles formed of Ag may be used in a mixed state. Furthermore, particles formed of C or particles formed of Ag may be used in a mixed state with particles formed of Si-Al glass. By including particles formed of either C or Ag in the first particles 32, the strength of the multilayer ceramic capacitor 10 can be improved.

[0054] <Tilt Angle of First Particles> Next, the tilt angle of the first particles 32 will be described. Note that this may also be simply referred to as the angle. Referring to FIGS. 4(B-1) to 4(C), the angle of the first particles 32 with respect to the perpendicular line NL1 to the side surface S20 of the laminated portion 20, which is the interface between the laminated portion 20 and the side margin portion 18, is indicated by α. The angle α is the angle formed by the perpendicular line NL1 and the long side of the first particle 32. In this embodiment, the angle α is set to 45 degrees or less. The angle α may be set counterclockwise with respect to the perpendicular line NL1 as shown in FIG. 4(B-1) or clockwise with respect to the perpendicular line NL1 as shown in FIG. 4(B-2). Furthermore, the angle α of the first particles 32 may be set to 0° as shown in FIG. 4(C). Setting the tilt angle of the first particles 32 in this manner is believed to improve the efficiency of discharging organic components from the ceramic body 11. If the angle α is greater than 45 degrees, such as 50 degrees, it is considered that the efficiency of discharging organic components will decrease. Also, if the angle α is greater than 45 degrees, it is considered that the effect of improving the bonding strength between the objects to be bonded will be low.

[0055] 4(B-1) to 4(C) show the joint between the stack portion 20 and the side margin portion 18, the angle α is similarly defined in the joint between the capacitance forming portion 16 and the cover portion 17 shown in FIG. 2(C). In this case, the angle α is the angle of the first particle 34 with respect to the perpendicular line NL2 to the main surface M16 of the capacitance forming portion 16.

[0056] Furthermore, the first particles 32 do not necessarily need to be arranged parallel to each other. It is sufficient that the angle α of each first particle 32 with respect to the perpendicular line NL1 or NL2 is set to 45 degrees or less. For example, the first particles 32 in the states shown in Figures 4(B-1) to 4(C) may be mixed.

[0057] <Abundance Ratio of First Particles Having a Predetermined Tilt Angle> Next, the abundance ratio of the first particles 32 having a tilt angle α of 45 degrees or less will be described. Here, the abundance ratio is, for example, the ratio of the first particles 32 present on the side surface S20 of the laminated portion 20 that have a tilt angle α of 45 degrees or less. The abundance ratio may be evaluated separately for the side surface S20 of the laminated portion 20 and the main surface M16 of the capacitance forming portion 16. Alternatively, an arbitrary region may be set and evaluated as the abundance ratio in that region. In this embodiment, the abundance ratio of the first particles 32 having a tilt angle α of 45 degrees or less is set to 80% or more.

[0058] By setting the abundance ratio of the first particles 32 having the inclination angle α of 45 degrees or less to 80% or more, it is believed that the efficiency of discharging organic components can be improved and the bonding strength between the objects to be bonded can be improved.

[0059] <<Ratio of Size of First Particles to Size of Particles Forming the Protective Layer>> Next, the ratio of the size of the first particles 32 to the size of the second particles 31 (33) forming the protective layer will be described.

[0060] As described above, the side margin portion 18 serving as a protective layer is formed from a material with a perovskite structure containing barium (Ba) and titanium (Ti). In Fig. 2(B), the second particles 31 forming the side margin portion 18 are depicted as being roughly circular. However, Fig. 2(B) is a schematic depiction of the state of portion S1 in Fig. 1(A), and the shape of the second particles 31 and the dimensional ratio with respect to the first particles 32 do not accurately represent the actual state.

[0061] In this embodiment, the ratio of the size of the second particles 31 to the size of the first particles 32 is 0.8 times or more and 2.0 times or less. Here, the size of the second particles 31 can be determined, for example, by measuring the maximum grain diameter from end to end of the particle multiple times and evaluating the D50 diameter. Specifically, a cross-sectional photograph is taken using a scanning electron microscope (SEM), and the maximum grain diameter of a predetermined number (e.g., 200) of second particles 31 is measured and evaluated using the D50 diameter. In this embodiment, the second particles 31 can be set in the range of 0.10 μm or more and 0.30 μm or less. Similarly, the size of the first particles 32 can be determined, for example, by measuring the maximum grain diameter from end to end of the particle multiple times and evaluating the D50 diameter. Specifically, a cross-sectional photograph is taken using an SEM, and the maximum grain diameter of a predetermined number (e.g., 200) of first particles 32 is measured and evaluated using the D50 diameter. In this embodiment, the first particles 32 can be set to have a size in the range of 0.08 μm to 0.60 μm. The second particles 31 and the first particles 32 can be distinguished based on their aspect ratios.

[0062] By setting such a ratio, it is possible to maintain the electrical characteristics of the multilayer ceramic capacitor 10. The first particles 32 are arranged in the capacitance forming portion 16. Therefore, the first particles 32 may become foreign matter in the capacitance forming portion 16. If the amount of impurities present in the capacitance forming portion 16 becomes large, there is a possibility that the short-circuit rate in the multilayer ceramic capacitor 10 will increase. Here, the short-circuit rate is the rate of multilayer ceramic capacitors 10 that have poor conductivity among a predetermined number (e.g., 100) of multilayer ceramic capacitors 10.

[0063] Therefore, in this embodiment, the ratio of the size of the second particles 31 to the size of the first particles 32 is set to 2.0 or less to prevent the first particles 32 from acting as impurities in the capacitance forming portion 16. On the other hand, if the size of the first particles 32 is small, the bonding strength between the objects to be bonded decreases, increasing the possibility of poor attachment of the side margin portion 18. Therefore, in this embodiment, the ratio of the size of the second particles 31 to the size of the first particles 32 is set to 0.8 or more to ensure the bonding strength between the objects to be bonded.

[0064] The relationship between the second particles 33 and the first particles 32 that form the cover portion 17 shown in FIG. 2C is similar to the relationship between the second particles 31 and the first particles 32 .

[0065] <<Frequency of First Particles>> Next, the frequency of first particles 32 will be described. The frequency of first particles 32 can be evaluated by the distance SP between adjacent first particles 32, as shown in FIGS. 4(B-1) and 4(C). Note that FIGS. 4(B-1) and 4(C) are schematic views of the arrangement of first particles 32 in the cross section of the multilayer ceramic capacitor 10. Therefore, not all first particles 32 are necessarily arranged at equal intervals, maintaining the distance SP. Therefore, the spacing between first particles 32 can be measured at multiple locations, and the frequency can be evaluated based on the average value. In this embodiment, the frequency of first particles 32 can be set in the range of 1 μm / particle to 2 μm / particle. In other words, SP can be set to 1 μm / particle to 2 μm / particle. Converting the frequency of first particles 32 into the number of first particles 32 per unit area results in a frequency of 0.25 particles / μm. ２ 1 piece / μm or more ２ The range is as follows:

[0066] If the presence frequency is set to a value greater than 2 μm / particle, the bonding strength between the objects to be joined may decrease, possibly causing peeling of the side margin portion 18. On the other hand, if the presence frequency is set to a value less than 1 μm / particle, the first particles 32 may approach each other, possibly increasing the rate of short circuits. For example, if the first particles 32 are formed of conductive particles such as C or Ag, the first particles 32 arranged between the internal electrodes 12 and 13 may cause short circuits. Furthermore, if the first particles 32 are formed of non-conductive particles such as Si or Al, electric field concentration occurs at the location where the first particles 32 are arranged, making the area more susceptible to dielectric breakdown.

[0067] Here, with reference to Figures 5(A) to 5(C), differences in action due to differences in the frequency of the first particles 32 will be described. Note that such differences in the frequency of the first particles 32 are caused by differences in the amount of the first particles 32 added. As shown by arrow 1a in Figure 5(A), degassing channels through which organic components are discharged are formed between the first particles 32. The formation of such degassing channels promotes the discharge of organic components, and can shorten the binder removal time in the manufacturing process.

[0068] Next, referring to Fig. 5(B), the amount of the first particles 32 added is increased, and the first particles 32 are closer to each other compared to the state shown in Fig. 5(A). In the state shown in Fig. 5(B), it is possible to improve the bonding strength between the objects to be bonded while ensuring a degassing flow path.

[0069] Next, FIG. 5C shows a state in which the amount of first particles 32 added is further increased compared to the state shown in FIG. 5B. FIG. 5C shows a state in which adjacent first particles 32 formed agglomerates during the manufacturing process of the multilayer ceramic capacitor 10 due to the first particles 32 being too close to each other. The agglomerations of the first particles 32 transform them into first particles 32' with a large aspect ratio. The formation of the first particles 32' blocks the degassing flow path, making it difficult for organic components to be discharged. This results in a longer binder removal time. Furthermore, the wedge effect of the first particles 32' is reduced, making the side margin portion 18 and the cover portion 17 more likely to peel off. Furthermore, the area in which the first particles 32 penetrate into the capacitance-forming portion 16 increases, potentially resulting in an increased short-circuit rate.

[0070] The frequency of the first particles 32 in this embodiment can be evaluated by the number of first particles 32 per unit area, taking into consideration these effects of the first particles 32. The frequency of the first particles 32 is 0.25 particles / μm ２ 1 piece / μm or more ２ It can be set appropriately within the following ranges.

[0071] The frequency of the first particles 32 may be evaluated by the number of first particles 32 per unit distance. In this case, the frequency of the first particles 32 can be appropriately set in the range of 1 μm / particle to 2 μm / particle. Here, 1 μm / particle means that the first particles 32 are arranged at intervals of 1 μm along the X-axis direction or the Y-axis direction. 2 μm / particle means that the first particles 32 are arranged at intervals of 2 μm along the X-axis direction or the Y-axis direction.

[0072] The number of first particles 32 per unit distance and the number of first particles 32 per unit area can be converted as follows. For example, if the number of first particles 32 per unit distance is 1 μm / particle, one first particle 32 exists within an area of ​​1 μm×1 μm. ２ Therefore, when this state is expressed in terms of the number of first particles 32 per unit area, it is 1 particle / μm ２Similarly, when the number of first particles 32 per unit distance is 2 μm, one first particle 32 exists within a range of 2 μm×2 μm. ２ Therefore, when this state is expressed in terms of the number of first particles 32 per unit area, it is 0.25 particles / μm ２ This becomes:

[0073] <Ratio of Dimensions of Portions Located Within Capacitance Forming Portions to Dimensions of Portions Located Within Side Margin Portions> Next, with reference to FIG. 4B-1 , the ratio of the dimension b1 of the portion of each first particle 32 located within the capacitance forming portion 16 to the dimension b2 of the portion located within the side margin portion 18 will be described. The first particles 32 are arranged across the capacitance forming portion 16 and the side margin portion 18. The first particles 32 are arranged at the boundary between the capacitance forming portion 16 and the side margin portion 18 so that the ratio b1:b2 of the long side dimensions b of each first particle 32 is in the range of 1:3 to 3:1. A small b1 has a small effect on the electrical characteristics but a low adhesion effect. Conversely, a large b1 has a large effect on the electrical characteristics but a high adhesion effect. By setting the ratio b1:b2 in consideration of these balances, it is possible to reduce the short-circuit rate in the multilayer ceramic capacitor 10 and improve the bonding strength between the capacitance forming portion 16 and the side margin portion 18.

[0074] This ratio is also applied to the first particles 32 arranged in the joint between the cover portion 17 and the side margin portion 18. In other words, this ratio is applied throughout the entire joint between the stack portion 20 and the side margin portion 18.

[0075] The ratio between the dimension of the portion located inside the capacitance forming portion 16 and the dimension of the portion located inside the cover portion can also be set to a similar ratio.

[0076] [Manufacturing Method] Next, an example of a method for manufacturing the multilayer ceramic capacitor 10 will be described with reference to FIGS. 6 to 12B. FIG. 6 is a flowchart illustrating an example of a method for manufacturing the multilayer ceramic capacitor 10 according to the embodiment. FIG. 7 is a perspective view illustrating some steps included in the method for manufacturing the multilayer ceramic capacitor 10 according to the embodiment. FIG. 8 is an explanatory diagram schematically illustrating the spraying of first particles 34 onto the main surface M16 of the capacitance forming portion 16. FIGS. 9A to 9D are explanatory diagrams illustrating some steps included in the method for manufacturing the multilayer ceramic capacitor according to the embodiment. FIG. 10 is a plan view illustrating a cutting step included in the method for manufacturing the multilayer ceramic capacitor 10 according to the embodiment. FIG. 11A is a perspective view of an unsintered laminate 200 created by cutting a laminate sheet 104 on which a cover portion 17 is laminated, and FIG. 11B is an explanatory diagram schematically illustrating the spraying of first particles 32 onto the side surface S200 of the unsintered laminate 200. FIG. 12 is an explanatory diagram that shows a schematic view of how an unsintered side margin sheet 118 that forms the side margin portion 18 is attached to the side surface of the unsintered capacitance forming portion onto which the first particles 32 have been sprayed.

[0077] In step S10, unsintered capacitor-forming sheets 101 and 102 (see FIG. 7), an unsintered cover sheet 117 (see FIGS. 9A to 9D), and an unsintered side margin sheet 118 (see FIG. 12) are prepared.

[0078] First, the materials for forming each sheet are blended. Specifically, an organic binder and an organic solvent serving as a dispersant and a molding aid are added to a dielectric material powder, which is then pulverized and mixed to form a mud-like slurry. The dielectric material powder may include, for example, ceramic powder. The dielectric material powder may also include an additive. The additive may be, for example, an oxide or glass of Mg, Mn, V, Cr, Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Co, Ni, Li, B, Na, K, or Si. The organic binder may be, for example, polyvinyl butyral resin or polyvinyl acetal resin. The organic solvent may be, for example, ethanol or toluene.

[0079] In this embodiment, as will be described later, the first particles 32 are used to bond the ceramic laminate 116 to the unsintered cover sheet 117 and to bond the unsintered laminate portion 200 to the unsintered side margin sheet 118. The first particles 32 improve the bonding strength between the objects to be bonded. Therefore, in this embodiment, the amount of organic binder can be reduced compared to conventional methods.

[0080] Next, the green capacitor-forming sheets 101 and 102 are fabricated by applying a slurry containing the ceramic powder blended with the above-described materials to a carrier film in a sheet form and drying the applied slurry. The carrier film is, for example, a polyethylene terephthalate (PET) film. The slurry can be applied using a doctor blade method, a die coater method, a gravure coater method, or the like.

[0081] Then, the internal electrode conductive paste is applied in a predetermined pattern to the green sheets of the layers forming the internal electrodes 12 and 13 among the multiple green sheets. This results in an unsintered capacitor forming portion sheet 101 on which the internal electrode pattern 112 is formed and an unsintered capacitor forming portion sheet 102 on which the internal electrode pattern 113 is formed. The internal electrode conductive paste contains powder of the metal used as the material for the internal electrodes 12 and 13. For example, if the metal used as the material for the internal electrodes 12 and 13 is Ni, the internal electrode conductive paste contains Ni powder. The internal electrode conductive paste also contains a binder, a solvent, and, if necessary, an auxiliary agent. The internal electrode conductive paste may contain the ceramic material, which is the main component of the dielectric layer 19, as a co-material. Screen printing, inkjet printing, gravure printing, or the like can be used to apply the internal electrode conductive paste.

[0082] As shown in FIG. 7, the green capacitor forming portion sheets 101 and 102 are stacked along the Z-axis direction to form a green ceramic laminate 116 that will become the capacitor forming portion 16 .

[0083] The unfired cover sheet 117 and the unfired side margin sheet 118 are prepared by forming green sheets to a predetermined thickness.

[0084] Next, in step S11, first particles 34 are sprayed onto one main surface M116 of the stacked green capacitor-forming sheets 101, 102, i.e., the green ceramic laminate 116. The first particles 34 are sprayed, for example, by a blasting method. The first particles 34 are sprayed vertically from a nozzle 40, as indicated by arrow 1b. In contrast, the green ceramic laminate 116 is disposed so that the main surface M116 forms a predetermined angle with respect to the direction indicated by arrow 1b. Here, the predetermined angle is an angle that can achieve the angle α shown in FIGS. 4(B-1) and 4(B-2). To be positioned at such an angle, the ceramic laminate 116 is placed, for example, on a stage covered with an adhesive sheet.

[0085] It should be noted that by spraying the first particles 34 onto the ceramic laminate 116 while heating it, the first particles 34 can be made to stick more easily into the main surface M116.

[0086] The amount of the first particles 34 to be sprayed is appropriately set based on the specifications of the final product.

[0087] The spraying direction of the first particles 34 and the arrangement of the main surface M116 may be any direction that can realize a predetermined angle between them. For example, the main surface M116 may be set to be horizontal, and the nozzle 40 may be set to be rotated from the vertical direction.

[0088] Next, in step S12, vibration is applied to the ceramic laminate 116. This removes the first particles 34 that were unable to penetrate the main surface M116. In a later step, an unsintered cover sheet 117 will be laminated on the main surface M116. By vibrating the ceramic laminate 116, excess first particles 34 that do not contribute to bonding between the main surface M116 and the unsintered cover sheet 117 are removed. Note that instead of vibration, excess first particles 34 may be removed by, for example, blowing air.

[0089] Next, in step S13, an unsintered cover sheet 117 is laminated on one of the main surfaces M116. Referring to Figures 9(A) and 9(B), the unsintered cover sheet 117 is laminated on one of the main surfaces M116 of the ceramic laminate 116 onto which the first particles 34 have been sprayed. At this time, by pressing the unsintered cover sheet 117 relatively against the main surface M116 while heating the unsintered cover sheet 117, it is possible to make it easier for the first particles 34 to penetrate the unsintered cover sheet 117.

[0090] Next, in step S14, the first particles 34 are sprayed onto the stacked green capacitor-forming sheets 101, 102, i.e., onto the other main surface M116 of the green ceramic laminate 116. In addition, in step S15, the ceramic laminate 116 is vibrated. These steps are common to steps S11 and S12, and therefore, detailed description thereof will be omitted here.

[0091] Next, in step S16, an unsintered cover sheet 117 is laminated on the other main surface M116. Referring to Figures 9(C) and 9(D), the unsintered cover sheet 117 is laminated on the other main surface M116 of the ceramic laminate 116 onto which the first particles 34 have been sprayed. At this time, by pressing the unsintered cover sheet 117 relatively against the main surface M116 while heating the unsintered cover sheet 117, it is possible to make it easier for the first particles 34 to penetrate the unsintered cover sheet 117.

[0092] After laminating unsintered cover sheets 117 on both main surfaces M116, the ceramic laminate 116 is pressed to pressure-bond the stacked green sheets. As a method for pressure-bonding the ceramic laminate 116, for example, a method of sandwiching the laminated block between resin films and isostatically pressing can be used.

[0093] Next, in step S17, the ceramic laminate 116 is cut into individual pieces to form rectangular parallelepiped unsintered laminate portions 200 (see FIG. 11A). The unsintered laminate portions 200 correspond to the laminate portion 20 after firing. Referring to FIG. 10, the unsintered laminate portions 200 are formed by cutting the ceramic laminate 116 along cutting lines Lx and Ly. For example, a press cutter blade or a rotary blade can be used to cut the ceramic laminate 116.

[0094] Next, in step S18, as shown in FIG. 11(B), first particles 32 are sprayed onto one side surface S200 of the unsintered laminated section 200. Then, in step S19, the unsintered laminated section 200 is vibrated. Furthermore, in step S20, the first particles 32 are sprayed onto the other side surface S200 of the unsintered laminated section 200. Then, in step S21, the unsintered laminated section 200 is vibrated. These steps can be performed in the same manner as steps S11 and S12. Therefore, when the first particles 32 are sprayed in step S18 or step S20, as shown in FIG. 11(B), the side surface S200 is relatively inclined so that the direction in which the first particles 32 are sprayed, indicated by arrow 1b, and the side surface S200 form a predetermined angle. This forms an inclination angle α (see FIGS. 4(B-1) to 4(C)). Furthermore, by spraying the first particles 32 onto the unsintered laminated portion 200 while heating it, the first particles 32 can be made to stick more easily into the side surface S200.

[0095] Next, in step S22, as shown in FIG. 12 , the unsintered side margin sheet 118 is attached to both side surfaces S200. The unsintered side margin sheet 118 is pressed against the side surfaces S200 while being heated. This allows the first particles 32 to easily penetrate the unsintered side margin sheet 118. A conventionally known method can be used to attach the unsintered side margin sheet 118 to the side surfaces S200. When the unsintered side margin sheet 118 is laid down and the unsintered laminated portion 200 is placed on top of it and then joined, the weight of the unsintered laminated portion 200 causes the unsintered side margin sheet 118 to adhere to the side surfaces S200. Here, by pressing the unsintered side margin sheet 118 against the side surfaces S200, the unsintered side margin sheet 118 can be more reliably attached to the unsintered laminated portion 200.

[0096] Next, in step S23, a binder removal process is performed. In the binder removal process, the organic binder contained in the unsintered laminated portion 200 to which the unsintered side margin sheet 118 is attached is removed. In the removal of the organic binder, for example, N ２ The unfired laminated portion 200 is heated in the atmosphere. In this embodiment, the amount of organic binder itself can be reduced, and further, a degassing flow path is secured as shown in Figures 5(A) and 5(B). Therefore, the time required for the binder removal process can be shortened.

[0097] Next, in step S24, an external electrode base portion is formed, followed by firing in step S25. Then, in step S26, a plating process is performed to form the external electrodes 14, 15. These steps can be performed using conventionally known methods, and therefore, detailed description thereof will be omitted here.

[0098] Through the above steps, the multilayer ceramic capacitor 10 of this embodiment can be obtained.

[0099] [Effects] In the multilayer ceramic capacitor 10 of this embodiment, the first particles 32 (34) are disposed at the interfaces between the capacitance forming portion 16 and the cover portion 17 or the side margin portion 18, thereby suppressing peeling at these joints. Furthermore, by disposing the first particles 32 (34), the amount of organic binder can be reduced. However, an increase in the amount of organic binder deteriorates binder removal and increases the amount of liquid components, thereby reducing the density of the multilayer ceramic capacitor 10. Deterioration in density also deteriorates the moisture resistance of the multilayer ceramic capacitor 10, resulting in reduced product reliability. For this reason, increasing the firing temperature to improve density is considered. However, increasing the firing temperature raises concerns about degrading the electrical characteristics of the multilayer ceramic electronic component, such as causing the internal electrodes to become spherical or reducing the continuity ratio of the internal electrodes. In this embodiment, the inclusion of the first particles 32 (34) can suppress peeling of the side margin portion 18 or the cover portion 17 without increasing the amount of organic binder. Furthermore, since the amount of organic binder is small, good binder removal properties can be ensured.

[0100] Next, examples of the multilayer ceramic capacitor 10 described in the embodiment will be described with reference to Tables 1 and 2, in comparison with comparative examples.

[0101] Examples 1 to 7 were prepared as examples. Comparative examples 1 to 8 were prepared as comparative examples. However, among Examples 1 to 7, in Example 4, the first particles were added only to the interface of the cover portion 17, and in the remaining Examples, the first particles were added only to the interface of the side margin portion 18.

[0102] Table 1 shows the specifications of Examples 1 to 4 and Comparative Examples 1 to 3. Table 1 also shows the time saved in binder removal and the rate of defective attachment in these Examples and Comparative Examples. Table 2 shows the specifications of Example 1, Examples 5 to 7, and Comparative Examples 4 to 8. Table 2 also shows the rate of short circuits and the rate of defective attachment in these Examples and Comparative Examples.

[0103] The time saved in binder removal indicates the percentage of time it took to complete binder removal compared to the time required for binder removal in Comparative Example 1. Completion of binder removal is determined by determining whether the weight of the unsintered laminated section 200 before the start of binder removal processing has reached the weight of the unsintered laminated section 200 expected after binder removal. The rate of defective attachment is calculated from the results of visual inspection to determine whether peeling has occurred in the side margin section 18 or the cover section 17. The rate of short circuits is calculated as the percentage of those with poor conductivity out of 100 multilayer ceramic capacitors.

[0104] In Example 1, the particle size ratio is 0.8, the aspect ratio of the first particles 32 is 0.3, and the frequency of the first particles 32 is 0.25 pieces / μm ２ The angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was 80%. The frequency of the first particles 32 was measured in an SEM image using a 10 μm×10 μm=100 μm ２ The number of first particles 32 present within the range of 1 μm ２ This method was also used in other examples and comparative examples.

[0105] In Example 2, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was 45 degrees, and the proportion of the first particles 32 with an angle α of 45 degrees was 80%.

[0106] In Example 3, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was 100%.

[0107] In Example 4, the particle size ratio was 0.8, the aspect ratio of the first particles 34 was 0.3, and the frequency of the first particles 34 was 0.25 pieces / μm ２The particle size of the first particles 34 was 2 μm / particle, the angle α of the first particles 34 was set to 30 degrees, and the proportion of the first particles 32 having an angle α of 30 degrees was 80%. However, the addition position of the first particles 34 in Example 4 was only the interface of the cover portion 17 as described above.

[0108] In Example 5, the particle size ratio was 2.0, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0109] In Example 6, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.2, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0110] In Example 7, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 1 / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0111] On the other hand, Comparative Example 1 does not use the first particles 32 .

[0112] In Comparative Example 2, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 50 degrees, and the proportion of the first particles 32 with an angle α of 50 degrees was set to 80%.

[0113] In Comparative Example 3, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 75%.

[0114] In Comparative Example 4, the particle size ratio was 0.7, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0115] In Comparative Example 5, the particle size ratio was 2.1, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0116] In Comparative Example 6, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.5, and the frequency of the first particles 32 was 0.25 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of the first particles 32 with an angle α of 30 degrees was set to 80%.

[0117] In Comparative Example 7, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 0.16 pieces / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of first particles 32 with an angle α of 30 degrees was set to 80%. Note that when the frequency is 2.5 μm / particle, one first particle 32 exists within a range of 2.5 μm × 2.5 μm. In other words, the proportion of first particles 32 with an angle α of 6.25 μm is 80%. ２ Therefore, when this state is expressed in terms of the number of first particles 32 per unit area, it becomes 0.16 particles / μm ２ This becomes:

[0118] In Comparative Example 8, the particle size ratio was 0.8, the aspect ratio of the first particles 32 was 0.3, and the frequency of the first particles 32 was 4 particles / μm ２ The set value of the angle α of the first particles 32 was set to 30 degrees, and the proportion of first particles 32 with an angle α of 30 degrees was set to 80%. Note that when the frequency is 0.5 μm / particle, one first particle 32 exists within a range of 0.5 μm × 0.5 μm. In other words, 0.25 μm ２ Therefore, when this state is expressed in terms of the number of first particles 32 per unit area, it is 4 particles / μm ２ This becomes:

[0119] First, Example 1 and Comparative Example 1 are compared. The bonding failure rate of Example 1 and the bonding failure rate of Comparative Example 1 were both 0%. However, the reduction in the time required for binder removal in Example 1 was 50%. In other words, binder removal was completed in Example 1 in half the time required in Comparative Example 1. This is thought to be because Example 1 was able to reduce the amount of organic binder, and furthermore, the first particles 32 formed degassing channels, providing good binder removal properties.

[0120] Next, Example 2 and Comparative Example 2 are compared. The binder removal time was reduced by 55% in Example 2. The binder removal time was reduced by 60% in Comparative Example 2. Comparing Example 2 and Comparative Example 2, the angle α of the first particles 32 in Example 2 is 45 degrees, while the angle α of the first particles 32 in the Comparative Example is 50 degrees. From these results, it can be concluded that if the angle α is too large, that is, if the first particles 32 are too flat, the binder removal performance will be reduced. Furthermore, the adhesion failure rate in Example 2 was 1%. The adhesion failure rate in Comparative Example 2 was 10%. From these results, it can be concluded that if the angle α is too large, peeling will be more likely to occur. From these results, it can be concluded that the upper limit of the angle α is 45 degrees.

[0121] Next, Example 3 and Comparative Example 3 are compared. The binder removal time was reduced by 50% in Example 3. The binder removal time was reduced by 55% in Comparative Example 3. The bonding failure rate in Example 3 was 0%. The bonding failure rate in Comparative Example 3 was 7%. Comparing Example 3 and Comparative Example 3, the proportion of first particles 32 having an angle α of 30 degrees in Example 3 was 100%, while the proportion of first particles 32 having an angle α of 30 degrees in Comparative Example 3 was 75%. From these results, it can be concluded that a decrease in the proportion of first particles 32 having an angle α of 30 degrees increases the binder removal time and makes bonding failures more likely to occur. From these results, it is desirable that the proportion of first particles 32 having an angle α of 30 degrees be 80% or more, as employed in Example 1.

[0122] Next, Example 4 will be described. In Example 4, only the interface of the cover portion 17 was examined, but similar to Example 1, the binder removal time was reduced by 50%. The bonding defect rate was also reduced to 0%. Note that the evaluation of the bonding defect rate in Example 4 is an evaluation of the cover portion 17.

[0123] Next, Example 5 is compared with Comparative Examples 4 and 5. The adhesion failure rate in Example 5 is 0%. The short circuit rate in Example 5 is also 0%. In contrast, the adhesion failure rate in Comparative Example 4 is 10%, and the short circuit rate is 0%. The adhesion failure rate in Comparative Example 5 is 7%, and the short circuit rate is 10%. Comparing Example 5 with Comparative Examples 4 and 5, the particle size ratio in Example 5 is 2.0, and the particle size ratio in Comparative Example 4 is 0.7. The particle size ratio in Comparative Example 5 is 2.1. The particle size ratio in Comparative Example 4 is smaller than the particle size ratio of 0.8 in Example 1. Therefore, it can be concluded that if the particle size of the first particles 32 is too small, the adhesion failure rate will be high. From these results, the particle size ratio can be set at a lower limit of 0.8, as used in Example 1. On the other hand, from the results of Comparative Example 5, it is considered that if the particle size ratio is too large, the short circuit rate will increase. From these results, the particle size ratio can be set at an upper limit of 2.0, as used in Example 5.

[0124] Next, Example 6 is compared with Comparative Example 6. The adhesion failure rate in Example 6 is 0%. Furthermore, the short-circuit rate in Example 6 is 0%. In contrast, the adhesion failure rate in Comparative Example 6 is 50% and the short-circuit rate is 30%. Comparing Example 6 and Comparative Example 6, the aspect ratio in Example 6 is 0.2, while the aspect ratio in Comparative Example 6 is 0.5. Therefore, it can be concluded that when the aspect ratio increases beyond a predetermined level, the adhesion failure rate and the short-circuit rate also increase. This is thought to be because, as the aspect ratio increases, it becomes more difficult for the first particles 32 to be stuck, and the area in which they penetrate into the capacitance forming portion 16 increases. Based on these results, the upper limit of the aspect ratio can be set at 0.3, as adopted in Example 1.

[0125] Next, Example 7 is compared with Comparative Examples 7 and 8. The adhesion failure rate of Example 7 is 0%. Also, the short circuit rate of Example 7 is 0%. In contrast, the adhesion failure rate of Comparative Example 7 is 6% and the short circuit rate is 0%. The adhesion failure rate of Comparative Example 8 is 0% and the short circuit rate is 5%. Comparing Example 7 with Comparative Examples 7 and 8, the frequency of the first particles 32 in Example 7 is 1 / μm ２ (1 μm / particle), and the frequency of the first particles 32 in Comparative Example 7 was 0.16 particles / μm ２ The frequency of the first particles 32 in Comparative Example 8 was 4 particles / μm (2.5 μm / particle). ２ Therefore, it can be evaluated that if the frequency of the first particles 32 becomes too low, the rate of defective attachment increases, and if the frequency of the first particles 32 becomes too high, the rate of short circuits increases. As a result, the frequency of the first particles 32 is set to 0.25 particles / μm as adopted in Example 1. ２ or more (2 μm / piece or less), and the 1 piece / μm employed in Example 7 ２ or less (1 μm / piece or more).

[0126]

[0127] Although the above embodiments have been described with reference to a multilayer ceramic capacitor as an example of a multilayer ceramic electronic component, the present invention is not limited thereto. For example, the configurations of the above embodiments can be applied to other multilayer ceramic electronic components such as varistors and thermistors.

[0128] The above-described embodiments are merely examples for implementing the present invention, and the present invention is not limited to these. Various modifications of these embodiments are within the scope of the present invention. Furthermore, it is obvious from the above description that various other embodiments are possible within the scope of the present invention.

[0129] 10... multilayer ceramic capacitor, 11... ceramic body, 12... first internal electrode, 13... second internal electrode, 14... first external electrode, 15... second external electrode, 16... capacitance forming portion, 17... cover portion, 18... side margin portion, 19... dielectric layer, 20... laminated portion, 31, 33... second particle, 32, 34... first particle, M11... first main surface, M12... second main surface, E11... first end face, E12... second end face, S11... first side surface, S12... second side surface, S20... laminated portion side surface, M16... capacitance forming portion main surface, S16... capacitance forming portion side surface

Claims

1. A multilayer ceramic electronic component comprising: a capacitance forming portion in which dielectric layers and internal electrodes are alternately stacked along a first axial direction, the capacitance forming portion having a pair of opposing main surfaces along the first axial direction, a pair of side surfaces opposing in a second axial direction perpendicular to the first axial direction and to which the internal electrodes are exposed, and a pair of end surfaces opposing in a third axial direction perpendicular to the first and second axial directions; a protective layer covering the capacitance forming portion with the main surfaces and the side surfaces as interfaces; particles present across the capacitance forming portion and the protective layer, the longest part in a cross section including the first axial direction being the long side and the longest part of the part perpendicular to the long side being the short side, and the ratio of the short side to the long side being 1 / 3 or less; and a pair of external electrodes covering at least the end faces, respectively.

2. The multilayer ceramic electronic component according to claim 1, wherein the protective layer includes a side margin portion covering the side surface from a direction along the second axial direction, and the particles are present across the capacitance forming portion and the side margin portion via the side surface which forms the interface between the capacitance forming portion and the side margin portion.

3. A multilayer ceramic electronic component as described in claim 1, wherein the capacitance forming portion is included in the protective layer and forms a laminated portion together with a cover portion laminated along the first axial direction, and the particles are present across the capacitance forming portion and the cover portion via a main surface of the capacitance forming portion which forms the interface between the capacitance forming portion and the cover portion.

4. The multilayer ceramic electronic component according to claim 1, wherein the particles contain any one of Si, Al, Mn, Mg, Zn, and a rare earth element.

5. The multilayer ceramic electronic component according to claim 1, wherein the particles contain either C or Ag.

6. The multilayer ceramic electronic component according to claim 1, wherein, when the first axis direction is a height direction, the second axis direction perpendicular to the direction along the first axis direction is a width direction, and the third axis direction perpendicular to the first axis direction and the second axis direction is a length direction, the height dimension of the multilayer ceramic electronic component is 1.3 times or more the width dimension or length dimension of the multilayer ceramic electronic component.

7. The multilayer ceramic electronic component according to claim 1, wherein the grains are inclined at an angle of 45 degrees or less with respect to the normal to the interface.

8. The multilayer ceramic electronic component according to claim 7, wherein the ratio of said grains having said inclination angle of 45 degrees or less is 80% or more.

9. The monolithic ceramic electronic component according to claim 1, wherein the ratio of the size of said particles to the size of the particles forming said protective layer is 0.8 to 2.0 times.

10. The frequency of the particles is 0.25 particles / μm ２ 1 piece / μm or more ２ The multilayer ceramic electronic component according to claim 1 , wherein:

11. The multilayer ceramic electronic component according to claim 2, wherein the ratio of the dimension of the portion of the grain located within the capacitance forming portion to the dimension of the portion located within the side margin portion is within a range of 1:3 to 3:

1.

12. The multilayer ceramic electronic component according to claim 3, wherein the ratio of the size of the portion of the grain located within the capacitance forming portion to the size of the portion located within the cover portion is within a range of 1:3 to 3:

1.

13. A method for manufacturing a multilayer ceramic electronic component, comprising the steps of: forming an unsintered laminated portion in which dielectric layers and internal electrodes are alternately stacked along a first axial direction, the unsintered laminated portion having a pair of main surfaces opposing each other along the first axial direction, a pair of side surfaces opposing each other in a second axial direction perpendicular to the first axial direction and from which the internal electrodes are exposed, and a pair of end surfaces opposing each other in a third axial direction perpendicular to the first and second axial directions, the unsintered laminated portion having the internal electrodes extended to each of the pair of end surfaces; spraying particles having a short side to long side ratio of 1 / 3 or less onto the side surfaces; and attaching a ceramic sheet forming a side margin portion to the side surfaces onto which the particles have been sprayed.

14. The method for producing a multilayer ceramic electronic component according to claim 13, further comprising the step of vibrating the unsintered laminated portion and removing excess particles on the side surface, which is carried out after the step of blasting the particles.

15. The method for producing a monolithic ceramic electronic component according to claim 13, wherein in the step of blowing the particles, the side surface is inclined with respect to the direction in which the particles are blown.

16. The method for producing a multilayer ceramic electronic component according to claim 13, wherein in the step of spraying the particles, the particles are sprayed onto the side surface while heating the unsintered laminated portion.

17. The method for producing a multilayer ceramic electronic component according to claim 13, wherein in the step of attaching the ceramic sheets that form the side margin portions, the ceramic sheets are pressed against the side surfaces while being heated.

18. The method for producing a multilayer ceramic electronic component according to claim 13, wherein the ceramic sheets forming the side margin portions are pressed and attached.

19. A method for manufacturing a multilayer ceramic electronic component as described in claim 13, comprising the steps of: spraying particles having a ratio of short side to long side of 1 / 3 or less onto a surface facing the first axial direction of a ceramic laminate in which ceramic sheets having unsintered internal electrodes formed thereon are stacked along the first axial direction; and stacking a ceramic sheet forming a cover portion on the surface onto which the particles have been sprayed.