Electronic component

Abstract

The present invention addresses the problem of providing an electronic component which is capable of reducing the vulnerability to an impact from the outside. This electronic component comprises: a main body which contains an insulating material; an internal conductor which is provided inside the main body; and a plurality of outer surface adhesion particles which are formed of a ceramic and adhere to the outer surface of the main body. The outer surface of the main body to which the plurality of outer surface adhesion particles adhere has a recess part. At least some of the plurality of outer surface adhesion particles are positioned in the recess part.

Description

Electronic Components

[0001] The present disclosure relates to an electronic component having an internal conductor disposed inside a body.

[0002] 2. Description of the Related Art Electronic components having an internal conductor inside a body include multilayer capacitors and inductors.

[0003] The corners of the outer surface of the electronic component are polished by a barrel device during the manufacturing process (see Patent Document 1).The electronic component is also placed on a measuring device when measuring its electrical characteristics (see Patent Document 2).

[0004] JP-A-5-96464 JP-A-6-186287

[0005] When polishing electronic components using a barrel device, there is a risk that the electronic components may be subjected to impact from the barrel device. When measuring electronic components using a measuring device, there is a risk that the measuring device may apply impact to the electronic components. The impact applied to the electronic components may cause the electronic components to crack. In particular, if the electronic components have recesses on their outer surfaces, there is a greater risk that the electronic components will crack due to external impact.

[0006] The present disclosure aims to provide an electronic component that can reduce vulnerability to external impacts.

[0007] An electronic component according to one aspect of the present disclosure comprises a body including an insulating material, an internal conductor disposed inside the body, and a plurality of ceramic particles attached to an outer surface of the body, wherein the outer surface of the body has a recess, and at least a portion of the plurality of particles are located in the recess.

[0008] According to the present disclosure, it is possible to provide an electronic component that can reduce vulnerability to external impacts.

[0009] Fig. 1 is a schematic external perspective view of an electronic component according to an embodiment of the present disclosure. Fig. 2 is a schematic exploded perspective view of the electronic component shown in Fig. 1. Fig. 3 is a schematic cross-sectional view showing a cross section taken along line III-III in Fig. 1. Fig. 3 is an enlarged view showing a portion surrounded by a dashed line in Fig. 3. Fig. 4 is an enlarged view showing a modified example of the portion surrounded by a dashed line in Fig. 3. Fig. 4 is an enlarged view showing a modified example of the portion surrounded by a dashed line in Fig. 3. Fig. 5 is a flowchart for explaining a method for manufacturing an electronic component. Fig. 6 is a diagram showing evaluation of crack defects in examples and comparative examples.

[0010] An example of the present disclosure will now be described with reference to the accompanying drawings. Note that the following description is merely illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses. The drawings are schematic, and the ratios of dimensions and the like do not necessarily correspond to reality. Furthermore, in the following description, terms indicating specific directions or positions (e.g., terms including "upper," "lower," "right," "left," "front," and "rear") are used as necessary. However, the use of terms indicating specific directions or positions is intended to facilitate understanding of the present disclosure with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present disclosure.

[0011] Fig. 1 is a perspective view of the appearance of an electronic component according to an embodiment of the present disclosure. Fig. 1 and Figs. 2 to 4, which will be described later, are schematic diagrams. Therefore, the size, shape, number, etc. of the main body 2, coil conductor 12, particles 21 attached to the outer surface, particles 22 inside the recesses, and filler particles 30 depicted in Figs. 1 to 4 may differ from the actual size, shape, number, etc.

[0012] As shown in FIG. 1 , an electronic component 1 according to an embodiment of the present disclosure includes a main body 2. In this embodiment, the main body 2 has a rectangular parallelepiped shape. In this embodiment, the outer surface 2A of the main body 2 includes an upper surface 3 facing upward, a lower surface 4 facing downward, and a front side surface 5, a rear side surface 6, a left side surface 7, and a right side surface 8 connecting the upper surface 3 and the lower surface 4. The front side surface 5 faces forward, and the rear side surface 6 faces backward. The left side surface 7 faces left, and the right side surface 8 faces right. In each figure, the X, Y, and Z directions are indicated by arrows. In this embodiment, the X direction is the front-to-back direction, the Y direction is the left-to-right direction, and the Z direction is the up-down direction. The X, Y, and Z directions are perpendicular to each other. Note that the main body 2 is not limited to a rectangular parallelepiped shape and may have other shapes, such as a cylindrical shape.

[0013] Fig. 2 is an exploded perspective view of the electronic component shown in Fig. 1. Fig. 3 is a schematic cross-sectional view showing a cross section taken along line III-III in Fig. 1. Fig. 4 is an enlarged view showing a portion surrounded by a dashed line in Fig. 3. Note that external electrodes 15 and 16 are omitted from Figs. 3 and 4.

[0014] As shown in FIGS. 2 and 3 , the main body 2 has a layered structure formed by stacking multiple insulator layers 9A to 9F. The main body 2 contains an insulating material. In this embodiment, the insulator layers 9A to 9F are stacked in the X direction. The main body 2 is made of, for example, glass and filler particles 30 (see FIG. 4 ). It is sufficient that the main body 2 contains an insulating material. For example, the main body 2 may contain other materials, such as plastic, instead of glass. Furthermore, for example, the main body 2 may be made of only glass, which is an insulating material, or may be made of glass and a semiconductor, thereby forming a portion of the insulating material.

[0015] The filler particles 30 shown in Fig. 4 are made of ceramic. The filler particles 30 contain aluminum (Al) (e.g., alumina), magnesium (Mg), silicon (Si), barium (Ba), titanium (Ti), zirconium (Zr) (e.g., zirconia), etc. For example, the material of the filler particles 30 is celsian (BaAl ２ Si２ O ８ ), or fresnoite (e.g., Ba ２ TiSi ２ O ８ or Ba ２ TiGe ２ O ８ ) etc.

[0016] 4, in this embodiment, the filler particles 30 contained in the main body 2 have a polyhedral shape. However, the shape of each filler particle 30 is not limited to a polyhedral shape.

[0017] In this embodiment, the filler particles 30 include filler particles 31 located inside the main body 2 and filler particles 32 at least a portion of which is exposed to the outside of the main body 2. Most of the filler particles 30 are filler particles 31, and only a small portion of the filler particles 30 are filler particles 32. The filler particles 30 are part of the main body 2. Therefore, even if some of the filler particles 32 are exposed to the outside of the main body 2, it is unlikely that all of the filler particles 32 are located outside the main body 2 (such as the outer surface-adhered particles 21 and the recessed particle 22 described below). In this embodiment, the number of filler particles 32 whose volume 50% or more is exposed to the outside of the main body 2 is less than 0.00001 per 1 μm2 of the outer surface 2A of the main body 2.

[0018] The filler particles 30 do not have to be exposed to the outside. That is, the filler particles 30 may include the filler particles 31 but not the filler particles 32. Furthermore, the main body 2 may not include the filler particles 30.

[0019] 2 and 3 , the electronic component 1 includes a coil conductor 12 inside the main body 2. The coil conductor 12 is made of a conductive material, such as copper or silver. The coil conductor 12 is an example of an internal conductor. In this embodiment, the electronic component 1 is an inductor component having a coil inside the main body 2. However, the electronic component 1 is not limited to an inductor component, and may be any component that includes an internal conductor made of a conductive material inside the main body 2. For example, the electronic component 1 may be a multilayer capacitor, a chip resistor, or the like.

[0020] The coil conductor 12 includes a plurality of (five in this embodiment) conductor patterns 10A to 10E, one or more (four in this embodiment) via conductors 11A to 11D, and a plurality of connection patterns 14. In this embodiment, the coil conductor 12 includes a connection pattern 14 for each of the conductor patterns 10A and 10E.

[0021] Each of the multiple conductor patterns 10A-10E is provided at one of the interfaces between the insulator layers 9A-9F and extends along the interface to form a portion of a circular track. Here, the interfaces can also be rephrased as multiple imaginary inner surfaces 2B extending in the Y and Z directions and spaced apart in the X direction within the main body 2. The multiple conductor patterns 10A-10E are provided so as to form a portion of a circular track on each of the multiple imaginary inner surfaces 2B. The circular track may have any shape as long as it is circular. For example, in this embodiment, the circular track is rectangular, but it is not limited to a rectangular shape and may be circular, hexagonal, or the like.

[0022] Each of the via conductors 11A to 11D electrically connects two adjacent conductor patterns among the conductor patterns 10A to 10E. In this embodiment, the via conductors 11A to 11D are via hole conductors that penetrate any of the insulator layers 9B to 9E in the X direction.

[0023] The coil conductor 12 is formed by alternately connecting multiple conductor patterns 10A to 10E and one or more via conductors 11A to 11D, and extends in a spiral shape around an axis 101 extending in the X direction. That is, in this embodiment, a coil is formed by the coil conductor 12, and the axial direction of the coil is the X direction. This allows the electronic component 1 to function as an inductor. Note that the axial direction of the coil formed by the coil conductor 12 is not limited to the X direction, and may be, for example, the Y direction or the Z direction.

[0024] Conductive patterns 10A to 10E have pads 13A to 13H at the connection portions with via conductors 11A to 11D.

[0025] The coil conductor 12 is formed by sequentially connecting the conductor pattern 10A, the via conductor 11A, the conductor pattern 10B, the via conductor 11B, the conductor pattern 10C, the via conductor 11C, the conductor pattern 10D, the via conductor 11D, and the conductor pattern 10E.

[0026] Via conductor 11A is connected to conductive pattern 10A through pad 13A, and is connected to conductive pattern 10B through pad 13B.

[0027] Via conductor 11B is connected to conductive pattern 10B through pad 13C, and is connected to conductive pattern 10C through pad 13D.

[0028] Via conductor 11C is connected to conductive pattern 10C through pad 13E and to conductive pattern 10D through pad 13F.

[0029] Via conductor 11D is connected to conductive pattern 10D through pad 13G, and is connected to conductive pattern 10E through pad 13H.

[0030] 2, the conductor pattern 10B is shown separated from the insulator layer 9B. However, in reality, the conductor pattern 10B is in contact with the insulator layer 9B. The same is true for the other conductor patterns. Although the insulator layers 9A and 9F are made up of multiple insulator layers, they are simply referred to as insulator layers for convenience.

[0031] The number of conductor patterns 10A to 10E and via conductors 11A to 11D connected in sequence to form the coil conductor 12, the number of turns of the coil conductor 12, and the number of stacked insulator layers 9A to 9F are not limited to those shown in the figure and can be any number.

[0032] 1, the electronic component 1 has two external electrodes 15 and 16 on the outer surface 2A of the body 2. The external electrodes 15 and 16 are formed by plating an Ag base electrode with Ni and Sn, for example.

[0033] The external electrode 15 is provided on the entire left side surface 7 and on the left portions of the upper surface 3, lower surface 4, front side surface 5, and rear side surface 6. The external electrode 16 is provided on the entire right side surface 8 and on the right portions of the upper surface 3, lower surface 4, front side surface 5, and rear side surface 6. The external electrodes 15, 16 are spaced apart from each other.

[0034] 2 , a connection pattern 14 extending from a conductor pattern 10A provided along the interface between insulator layers 9A and 9B is connected to an external electrode 15. A connection pattern 14 extending from a conductor pattern 10E provided along the interface between insulator layers 9E and 9F is connected to an external electrode 16. In this way, one end of the coil conductor 12 is electrically connected to the external electrode 15 via the connection pattern 14 extending from the conductor pattern 10A. The other end of the coil conductor 12 is electrically connected to the external electrode 16 via the connection pattern 14 extending from the conductor pattern 10E. Note that the coil conductor 12 may be electrically connected to the external electrodes 15, 16 at portions other than the one end and the other end.

[0035] The positions at which the external electrodes 15, 16 are provided are not limited to the positions described above. For example, the external electrode 15 may be laminated on the entire upper surface 3 and on the upper parts of the front side surface 5, rear side surface 6, right side surface 8, and left side surface 7. Furthermore, for example, the external electrode 16 may be provided on the entire lower surface 4 and on the lower parts of the front side surface 5, rear side surface 6, left side surface 7, and right side surface 8.

[0036] The configuration of the external electrodes 15, 16 is not limited to the configuration described above. For example, the external electrode 15 may be provided only on the left side surface 7, or only on the left side surface 7 and the left portion of the lower surface 4. Furthermore, for example, the external electrode 16 may be provided only on the right side surface 8, or only on the right side surface 8 and the right portion of the lower surface 4.

[0037] The external electrodes 15, 16 are not limited to being provided on the outer surface 2A of the main body 2. For example, the external electrodes 15, 16 may be embedded in recesses provided in the main body 2 except for the surface portions exposed to the outside, or only the base electrodes may be embedded in the recesses, with the Ni plating and Sn plating protruding from the surface portions.

[0038] 4, the electronic component 1 has a plurality of outer surface-attached particles 21 attached to the outer surface 2A of the main body 2. Unlike the filler particles 30 described above, the outer surface-attached particles 21 are attached to the outer surface 2A of the main body 2 but are not part of the main body 2.

[0039] In this embodiment, the thickness of the outer surface 2A of the main body 2 is 1 (μm ２ The number of particles 21 adhering to the outer surface per 1 μm ２ ) or more. Preferably, the thickness of the outer surface 2A of the main body 2 is 1 (μm ２ The number of particles 21 adhering to the outer surface per 1 μm ２ ) or more. ２ The number of outer surface-adhering particles 21 per unit area is not limited to the range mentioned above.

[0040] The outer surface adhered particles 21 are made of ceramic, similar to the filler particles 30, and are made of aluminum (Al), magnesium (Mg), silicon (Si), barium (Ba), titanium (Ti), zirconium (Zr), etc. For example, the material of the outer surface adhered particles 21 is Al ２ O ３ (alumina), ZrO ２ (zirconia), SiO ２ (silica), SiC, B ４ C, Si ３ N ４ , Si ３ N ４ -Al ２ O ３ , AlN, ferrite, steatite, forsterite, mullite, cordierite, etc. The material of the outer surface-attached particles 21 is preferably alumina, zirconia, or silica. In this embodiment, the material of the outer surface-attached particles 21 is silica.

[0041] Each of the plurality of outer surface-attached particles 21 is spherical. A spherical shape is, for example, a shape that satisfies the following conditions 1 and 2. Condition 1 is that, in any cross section of one outer surface-attached particle 21, when circularity = (maximum diameter of the cross section - minimum diameter of the cross section) / (maximum diameter of the cross section), the circularity is < 0.1. Condition 2 is that the particle is not a polyhedron, which is characteristic of single crystals. In other words, in this embodiment, the filler particle 30 described above has a polyhedral shape and therefore does not satisfy condition 2. In other words, in this embodiment, the shape of each outer surface-attached particle 21 is different from the shape of each filler particle 30.

[0042] The particle diameter of the plurality of outer surface-attached particles 21 is 0.5 μm or more and 10 μm or less. Preferably, the particle diameter of the plurality of outer surface-attached particles 21 is 0.5 μm or more and 5 μm or less. In this embodiment, the particle diameter of the plurality of outer surface-attached particles 21 is the median diameter (D50). Note that the particle diameter of the plurality of outer surface-attached particles 21 is not limited to the median diameter (D50). For example, the particle diameter of the plurality of outer surface-attached particles 21 may be the average of the plurality of outer surface-attached particles 21. Furthermore, for example, the particle diameter of each of the plurality of outer surface-attached particles 21 may be 0.5 μm or more and 10 μm or less (preferably 0.5 μm or more and 5 μm or less). Note that the particle diameter of each outer surface-attached particle 21 is not limited to the above range. The particle diameter variation is preferably 30% or less in terms of the CV (Coefficient of Variation) value, and particularly preferably 10% or less.

[0043] As described above, in this embodiment, the material of the outer surface-adhering particles 21 is silica. On the other hand, in this embodiment, the material of the filler particles 30 is celsian (BaAl ２ Si ２ O ８ ), or fresnoite (e.g., Ba ２ TiSi ２ O ８ or Ba ２ TiGe ２ O ８ ) In other words, in this embodiment, the outer surface-adhering particles 21 are made of a material different from that of the filler particles 30 .

[0044] The shape of each outer surface-attached particle 21 is not limited to a spherical shape. The shape of each outer surface-attached particle 21 may be the same as the shape of each filler particle 30. Each outer surface-attached particle 21 may be made of the same material as each filler particle 30.

[0045] In this embodiment, the outer surface-attached particles 21 are attached to the entire outer surface 2A of the main body 2 (upper surface 3, lower surface 4, front surface 5, rear surface 6, left side surface 7, and right side surface 8), but may be attached to only a portion of the outer surface 2A of the main body 2. For example, the outer surface-attached particles 21 may be attached to four of the outer surfaces 2A (front surface 5, rear surface 6, left side surface 7, and right side surface 8). Furthermore, for example, the outer surface-attached particles 21 may be attached to five of the outer surfaces 2A (front surface 5, rear surface 6, left side surface 7, right side surface 8, and upper surface 3).

[0046] The outer surface 2A of the main body 2 has at least one recess 2Aa. In this embodiment, the outer surface 2A of the main body 2 has multiple recesses 2Aa. In this embodiment, the recesses 2Aa are formed unintentionally due to pressure acting on the outer surface 2A during the manufacturing process of the electronic component 1, the measurement process of the electronic component 1, etc., but this is not limiting. The recesses 2Aa may also be formed due to a factor other than pressure acting on the outer surface 2A. For example, the main body 2 may be designed to have the recesses 2Aa, in which case the recesses 2Aa are intentionally formed during the manufacturing process of the main body 2.

[0047] The portion of the outer surface 2A of the main body 2 where the recesses 2Aa are provided has lower mechanical strength than the other portion (the portion of the outer surface 2A of the main body 2 where the recesses 2Aa are not provided). For example, when external pressure is applied to the outer surface 2A of the main body 2, the pressure is more likely to cause the existing recesses 2Aa to become larger than the pressure is likely to cause the recesses 2Aa to be formed in the portion where no recesses 2Aa are present.

[0048] At least some of the multiple outer surface-attached particles 21 are located in the recess 2Aa. Specifically, at least some of the multiple outer surface-attached particles 21 are attached to a portion of the outer surface 2A of the main body 2 that defines the recess 2Aa. In Fig. 4, two outer surface-attached particles 21 are attached to the outer surface 2A located outside the recess 2Aa, while the majority of outer surface-attached particles 21, excluding these two outer surface-attached particles 21, are attached to the outer surface 2A that defines the recess 2Aa. In other words, in Fig. 4, two outer surface-attached particles 21 are located outside the recess 2Aa, while the majority of outer surface-attached particles 21 are located inside the recess 2Aa.

[0049] The electronic component 1 has at least one recess particle 22. In this embodiment, the electronic component 1 has a plurality of recess particles 22.

[0050] At least a portion of each of the recessed portion particles 22 is located inside the recessed portion 2Aa. That is, each of the recessed portion particles 22 may be located completely inside the recessed portion 2Aa (for example, the recessed portion particle 22A in FIG. 4), or only a portion of the recessed portion may be located inside the recessed portion 2Aa while the remaining portion protrudes from the recessed portion 2Aa (for example, the recessed portion particle 22B in FIG. 4).

[0051] Each of the recessed portion particles 22 is not in contact with the outer surface 2A of the main body 2. In other words, each of the recessed portion particles 22 is separated from the outer surface 2A of the main body 2. Each of the recessed portion particles 22 is in contact with the outer surface-adhered particles 21 that are attached to the outer surface 2A that defines the recess 2Aa.

[0052] At least a portion of the recess 2Aa is filled with at least one outer surface-adhered particle 21 and at least one inner-recess particle 22. In particular, the edge of the recess 2Aa is filled with the outer surface-adhered particles 21, and the portion of the recess 2Aa other than the edge is filled with the inner-recess particles 22. The edge of the recess 2Aa is the portion of the recess 2Aa that is near the outer surface 2A that defines the recess 2Aa. The center of the recess 2Aa is the portion of the recess 2Aa that is not near the outer surface 2A that defines the recess 2Aa.

[0053] When the recess 2Aa is small, the recess 2Aa can be filled only with the outer surface-adhered particles 21. When the recess 2Aa is filled only with the outer surface-adhered particles 21, no in-recess particles 22 are present in the recess 2Aa.

[0054] In this embodiment, the shape, size, and material of the recessed particle 22 are the same as those of the outer surface-attached particle 21. However, at least one of the shape, size, and material of the recessed particle 22 may be different from those of the outer surface-attached particle 21. Furthermore, each of the shape, size, and material of the recessed particle 22 may be the same as or different from those of the filler particle 30. Furthermore, the recessed particle 22 is not limited to ceramic.

[0055] The shape, size, and number of the recesses 2Aa are not limited to those shown in Fig. 4. Figs. 5, 6, and 7 are enlarged views showing modified examples of the portion surrounded by the dashed line in Fig. 3. For example, as shown in Fig. 5, multiple recesses 2Aa may be periodically arranged on the outer surface 2A of the main body 2. Furthermore, as shown in Fig. 6, the surface defining the recesses 2Aa may be curved. Furthermore, as shown in Fig. 7, the depth of the recesses 2Aa may be smaller than the particle size of the outer surface-adhered particles 21. In this case, some of the outer surface-adhered particles 21 protrude from the recesses 2Aa.

[0056] The electronic component 1 is manufactured, for example, as follows. Hereinafter, a method for manufacturing the electronic component 1 will be described with reference to Fig. 8. Fig. 8 is a flowchart for explaining the method for manufacturing the electronic component.

[0057] First, a conductive paste is prepared as follows (S10). An organic vehicle is prepared by adjusting the blending ratio of an organic binder to a solvent to, for example, 1:9. Next, the organic vehicle is mixed with conductive particles and kneaded using a triple roll mill. This produces a conductive paste. The average particle size of the conductive particles is, for example, 0.5 to 8.0 (μm), and preferably 1.0 to 5.0 (μm).

[0058] In this embodiment, the conductive paste is prepared so that the content of the conductive particles is 30 to 70 (vol %). That is, the conductive paste is composed of the conductive particles and the organic vehicle as described above.

[0059] The conductive particles are not particularly limited as long as they are conductive. For example, Ag, Pd, Pt, Au, Ni, Cu, or an alloy of two or more of these can be used as conductive particles. Ethyl cellulose resin, acrylic resin, butyral resin, etc. can be used as the organic binder contained in the organic vehicle. α-Terpineol, tetralin, butyl carbitol, etc. can be used as the solvent.

[0060] Next, a ceramic green sheet is prepared (S20). ２ O ３ A predetermined amount of ferrite-based material such as ferrite powder is weighed out. The weighed material is placed in a ball mill and wet-mixed and pulverized, followed by drying and calcination. Next, the calcined material is thoroughly wet-pulverized again in a ball mill and dried. This produces a calcined powder. Next, the calcined powder is mixed with a binder, a plasticizer, and a dispersant, and dispersed in a solvent. This produces a ceramic slurry. Next, the ceramic slurry is formed into a sheet by a doctor blade method or the like, to produce a ceramic green sheet. Multiple ceramic green sheets are produced.

[0061] Note that step S20 may be executed before step S10 or may be executed in parallel with step S10.

[0062] Next, via holes are drilled at predetermined positions in the ceramic green sheets, and the conductive paste prepared in step S10 is screen-printed on the surfaces of the ceramic green sheets, thereby forming coil patterns on the surfaces of the ceramic green sheets (S30). Step S30 is performed on some of the ceramic green sheets prepared in step S20.

[0063] Next, a bonded block is produced (S40). A plurality of ceramic green sheets on which coil patterns have been formed in step S30 are stacked so that they can be electrically connected in series through via holes. This forms a laminate. Note that if only one ceramic green sheet is produced in step S30, this single ceramic green sheet corresponds to the laminate. Next, the laminate is sandwiched and bonded by ceramic green sheets on which no coil patterns have been formed. This produces a bonded block.

[0064] Next, cutting and attachment are performed (S50). The bonded block is cut to a predetermined size using a dicer (e.g., DAD3350, manufactured by DISCO). Note that this cutting process is not limited to using a dicer. For example, the bonded block may be cut by selectively dissolving and removing the cut width using techniques such as alkaline development or acid etching. Alternatively, the bonded block may be cut by selectively degreasing and removing the cut width using a laser or a baking furnace. Next, to attach the outer surface-attached particles 21 (silica particles in this embodiment), a slurry is prepared in which silica particles are dispersed in water at a concentration of 20 (wt%), and each cut bonded block is immersed in the slurry. Thereafter, a water drying process is performed at a predetermined temperature (e.g., 60°C) and for a predetermined time (e.g., 120 minutes). This causes the outer surface-attached particles 21 to adhere to the outer surface of the bonded block. Note that the process of attaching the outer surface-attached particles 21 is not limited to this. That is, the means for achieving the state in which the outer surface-attached particles 21 are attached to the outer surface of the compressed block is not limited to this. For example, the outer surface-attached particles 21 may be attached to the outer surface of the compressed block by imprinting the outer surface-attached particles 21 in powder form using a press or the like. Alternatively, the outer surface-attached particles 21 may be arranged on at least one of the outermost layers by arranging a green sheet having inorganic filler as the outer surface-attached particles 21 on at least one of the outermost layers of the ceramic green sheet laminate.

[0065] Next, firing is performed (S60). After the binder is removed at a predetermined temperature (e.g., 500°C or less), firing is performed at a predetermined temperature (e.g., 800 to 900°C, preferably below the melting point of the outer surface-adhered particles 21), and a ceramic chip sintered body is produced. If necessary, ultrasonic cleaning is performed on the ceramic chip sintered body.

[0066] Next, external electrodes are formed (S70). After barrel polishing of the ceramic chip sintered body, a conductive paste is applied to both ends of the ceramic sintered body and baked. This forms the external conductive portion. For barrel polishing, a centrifugal barrel machine, for example, is used. Next, electrolytic plating is applied to sequentially form a nickel film and a tin film on the surface of the external conductive portion. This forms the external electrodes 15, 16. This completes the manufacturing process of the electronic component 1 having outer surface-adhered particles 21 attached thereto.

[0067] The method for manufacturing the electronic component 1 is not limited to the method described above. The method described above is a green sheet lamination method in which multiple ceramic green sheets are laminated, but other methods may be used. For example, a printing multilayer method in which paste is printed to a predetermined thickness using a screen and then dried repeatedly to laminate, a photolithography method in which a conductor or dielectric is patterned by light irradiation and development, or other methods may be used independently or in combination.

[0068] Electronic components (Examples 1 to 9 and Comparative Example) were fabricated using the method described above. A plurality of each of Examples 1 to 9 and Comparative Example was fabricated. Each of Examples 1 to 9 and Comparative Example was judged for crack defects using a sorting device (such as the sorting device disclosed in Japanese Patent Laid-Open No. 2005-725) that measures electrical characteristics and sorts the components into good and bad.

[0069] Examples 1 to 9 are electronic components having particles 21 attached to the outer surface. That is, Examples 1 to 9 are the electronic component 1 described above. As shown in FIG. 9, Examples 1 to 9 differ in at least one of the material of the particles 21 attached to the outer surface, the particle diameter (median diameter (D50) in this evaluation) of the particles 21 attached to the outer surface, and the attachment density of the particles 21 attached to the outer surface. The CV value of the particle diameter used for each is within 30%. The attachment density of the particles 21 attached to the outer surface is determined by dividing the particle diameter by 1 (μm ２ 9 is a diagram showing the evaluation of crack defects in the examples and comparative examples.

[0070] The outer surface-attached particles 21 in Example 1 are spherical zirconia. The outer surface-attached particles 21 in Examples 2 to 4 are spherical alumina. The outer surface-attached particles 21 in Examples 5 to 9 are spherical silica.

[0071] The comparative example does not have particles 21 attached to the outer surface.

[0072] The appearance inspection for determining the presence or absence of crack defects in Examples 1 to 9 and Comparative Example was performed by observation under a microscope (for example, VHX (manufactured by Keyence Corporation)). The magnification was, for example, 100 times. The appearance inspection may also be performed using a scanning electron microscope (SEM) described below.

[0073] The appearance of the outer surface-adhered particles 21 in Examples 1 to 9 was observed using a scanning electron microscope (SEM). The imaging magnification was 4000 / D, where D is the median diameter (D50) of the outer surface-adhered particles 21, and is expressed in μm. For example, when D=0.5 (μm), the imaging magnification was 8000x.

[0074] The material of the outer surface-attached particles in each of Examples 1 to 9 was identified using EDX analysis and WDX analysis. For example, when the material of the outer surface-attached particles 21 is alumina (Examples 2 to 4), Al and O are detected as the main components by the above analysis. Furthermore, when the material of the outer surface-attached particles 21 is silica (Examples 5 to 9), Si and O are detected as the main components by the above analysis. Furthermore, when the material of the outer surface-attached particles 21 is zirconia (Example 1), Zr and O are detected as the main components by the above analysis. Note that the shapes of the outer surface-attached particles 21, the particles in the recesses 22, and the filler particles 30 can be identified by the above analysis.

[0075] The chip size of Examples 1 to 9 and the comparative example is preferably 1005 size or less, more preferably 0603 size or less than the above range, and even more preferably 0402 size or less than the above range. In this evaluation, the chip size of Examples 1 to 9 and the comparative example was 0402 size.

[0076] Inductor components were used in Examples 1 to 9 and Comparative Example, but Examples 1 to 9 and Comparative Example are not limited to inductor components and may be multilayer capacitors, chip resistors, or the like.

[0077] The same number of chips from Examples 1 to 9 and Comparative Example (for example, 200 chips from each example) were evaluated for the presence or absence of cracks. The results are shown in Figure 9. Here, a chip was judged to have a crack if 5% or more of the area of ​​one surface of the chip was missing or if the length of the straight line connecting both ends of a crack on one surface of the chip was 50 μm or more; otherwise, a chip was judged to have no crack.

[0078] As shown in FIG. 9, the crack defect rate of the comparative example was 5.33(%), while the crack defect rates of Examples 1 to 9 were 2.33(%) or less, which was lower than that of the comparative example.

[0079] In Examples 2 to 4 in which the outer surface attached particles 21 were alumina, the cracking defect rate in Examples 2 and 4 in which the particle diameter of the outer surface attached particles 21 was small was lower than that in Example 3 in which the particle diameter of the outer surface attached particles 21 was larger than that in Examples 2 and 4. In Examples 5 to 9 in which the outer surface attached particles 21 were silica, the smaller the particle diameter of the outer surface attached particles 21 was, the lower the cracking defect rate was.

[0080] In Examples 2 to 4, in which the outer surface-attached particles 21 were alumina, the cracking defect rate in Example 4, in which the attachment density of the outer surface-attached particles 21 was high, was lower than that in Example 3, in which the attachment density of the outer surface-attached particles 21 was lower than that in Example 4. In Examples 5 to 9, in which the outer surface-attached particles 21 were silica, the cracking defect rate decreased as the attachment density of the outer surface-attached particles 21 increased. This is thought to be because crack depressions somewhat larger than 0.5 μm occurred in the element body, preventing the cracks from progressing. Therefore, when the size of the crack depressions differs, it is thought that it is preferable for the optimal particle size to also differ. In other words, it is preferable for the particle size to be controlled, and therefore the CV value is preferably within 30%, and particularly preferably within 10%.

[0081] The electronic component 1 described above can achieve the following effects.

[0082] According to this embodiment, the recess 2Aa can be filled with the outer surface-adhered particles 21. The presence of the outer surface-adhered particles 21 filling the recess 2Aa can prevent the recess 2Aa from becoming larger due to an external impact on the main body 2. For example, the presence of the outer surface-adhered particles 21 filling the recess 2Aa can prevent the recess 2Aa from progressing further into the main body due to an external impact on the main body 2. This reduces the possibility of the electronic component 1 cracking. In other words, the vulnerability of the electronic component 1 to external impacts can be reduced.

[0083] If the recess 2Aa is large, there is a risk that the recess 2Aa cannot be completely filled with only the outer surface-adhered particles 21 adhering to the outer surface 2A of the main body 2. According to this embodiment, in addition to the outer surface-adhered particles 21, the particles present in the recess 2Aa also include inner-recess particles 22. This increases the likelihood that the recess 2Aa will be completely filled, even if the recess 2Aa is large.

[0084] According to this embodiment, the outer surface-attached particles 21 are spherical, which makes it easier for the outer surface-attached particles 21 to adhere to the outer surface 2A of the main body 2 compared to a configuration in which the outer surface-attached particles 21 have a shape with corners such as a polygon.

[0085] According to this embodiment, the outer surface-adhering particles 21 and the filler particles 30 can be formed in shapes suited to their respective roles.

[0086] According to this embodiment, the materials of the outer surface-adhering particles 21 and the filler particles 30 can be selected to be suitable for their respective roles.

[0087] According to this embodiment, the possibility of the main body 2 cracking can be reduced compared to a configuration in which the outer surface 2A of the main body 2 does not have the outer surface-adhered particles 21 attached thereto.

[0088] When the particle size of each outer surface adhered particle 21 is 5 μm or less, the possibility of the main body 2 cracking can be reduced compared to a configuration in which the particle size of the outer surface adhered particles 21 is greater than 5 μm. When the particle size of each outer surface adhered particle 21 is less than 0.5 μm, the probability that the outer surface adhered particles 21 will be incorporated into the external electrodes during baking of the external electrodes increases, which may make it difficult to obtain the desired resistivity. According to this embodiment, the particle size of each outer surface adhered particle 21 is 0.5 μm or more, so the probability that the outer surface adhered particles 21 will be incorporated into the external electrodes can be reduced.

[0089] 1 (μm) of the outer surface 2A of the main body 2 ２ The number of particles 21 adhering to the outer surface per 100 μm ２ ) or more, 1 (μm ２ The number of particles 21 adhering to the outer surface per 100 μm ２) This reduces the possibility of the main body 2 cracking compared to a configuration with fewer wires.

[0090] The electronic components described above can also be expressed as follows.

[0091] (1) An electronic component according to one aspect of the present disclosure comprises: a body including an insulating material; an internal conductor disposed inside the body; and a plurality of ceramic particles attached to an outer surface of the body, wherein the outer surface of the body has a recess, and at least a portion of the plurality of particles are located in the recess.

[0092] (2) The electronic component of (1) may further include a particle in the recess, at least a portion of which is located inside the recess, spaced apart from the outer surface of the body, and in contact with at least one of the plurality of outer surface-adhered particles.

[0093] (3) In the electronic component of (1) or (2), each of the plurality of outer surface-attached particles may be spherical.

[0094] (4) In any one of the electronic components (1) to (3), the main body may include a plurality of filler particles made of ceramic, and the shape of each of the plurality of outer surface-attached particles may be different from the shape of each of the plurality of filler particles.

[0095] (5) In the electronic component of any one of (1) to (4), the main body may include a plurality of filler particles made of ceramic, and the plurality of outer surface-attached particles may be made of a material different from the plurality of filler particles.

[0096] (6) In the electronic component according to any one of (1) to (5), the particle diameter of the plurality of particles attached to the outer surface may be 0.5 μm or more and 10 μm or less.

[0097] (7) In the electronic component of (6), the particle diameter of the plurality of particles attached to the outer surface may be 0.5 (μm) or more and 5 (μm) or less.

[0098] (8) In any one of the electronic components (1) to (7), the thickness of the outer surface of the main body is 1 (μm２ The number of the outer surface-adhered particles per 1 μm ２ ) or more.

[0099] (9) In the electronic component of (8), 1 (μm) of the outer surface of the main body ２ The number of the outer surface-adhered particles per ２ ) or more.

[0100] (10) In the electronic component according to any one of (1) to (9), the plurality of particles attached to the outer surface may be silica.

[0101] (11) In the electronic component according to any one of (1) to (9), the plurality of particles attached to the outer surface may be zirconia.

[0102] (12) In the electronic component according to any one of (1) to (9), the plurality of particles attached to the outer surface may be alumina.

[0103] (13) In the electronic component according to any one of (10) to (12), the CV value of the plurality of particles adhering to the outer surface may be 30% or less.

[0104] Any of the various embodiments described above may be combined appropriately to achieve the effects of each of them.

[0105] While the present invention has been fully described in connection with preferred embodiments, with appropriate reference to the drawings, various changes and modifications will become apparent to those skilled in the art, and it is to be understood that such changes and modifications are included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

[0106] REFERENCE SIGNS LIST 1 Electronic component 2 Main body 2A Outer surface 2Aa Recess 12 Coil conductor 21 Particles attached to outer surface 22 Particles in recess 30 Filler particles

Claims

1. An electronic component comprising: a body containing an insulating material; an internal conductor provided inside the body; and a plurality of ceramic particles attached to the outer surface of the body, wherein the outer surface of the body has a recess, and at least a portion of the plurality of particles are located in the recess.

2. The electronic component of claim 1, further comprising a recessed particle at least partially located within said recess, spaced apart from the outer surface of said body and in contact with at least one of said plurality of outer surface-adhered particles.

3. The electronic component according to claim 1 or 2, wherein each of the plurality of outer surface-attached particles is spherical.

4. An electronic component according to any one of claims 1 to 3, wherein the body includes a plurality of filler particles made of ceramic, and the shape of each of the plurality of outer surface-attached particles is different from the shape of each of the plurality of filler particles.

5. An electronic component according to any one of claims 1 to 4, wherein the body includes a plurality of filler particles made of ceramic, and the plurality of outer surface-attached particles are made of a material different from the plurality of filler particles.

6. An electronic component according to any one of claims 1 to 5, wherein the particle diameter of the plurality of particles attached to the outer surface is 0.5 (µm) or more and 10 (µm) or less.

7. The electronic component according to claim 6, wherein the particle diameter of the plurality of particles attached to the outer surface is 0.5 μm or more and 5 μm or less.

8. 1 (μm) of the outer surface of the body ２ The number of the outer surface-adhered particles per 1 μm ２ 8. The electronic component according to claim 1, wherein the thickness of the first insulating film is 100 μm or more.

9. 1 (μm) of the outer surface of the body ２ The number of the outer surface-adhered particles per ２ 9. The electronic component according to claim 8, wherein the thickness is 100 nm or more.

10. The electronic component according to any one of claims 1 to 9, wherein the plurality of particles attached to the outer surface are silica.

11. The electronic component according to any one of claims 1 to 9, wherein the plurality of particles attached to the outer surface are zirconia.

12. The electronic component according to any one of claims 1 to 9, wherein the plurality of particles attached to the outer surface are alumina.

13. An electronic component according to any one of claims 10 to 12, wherein the CV value of the plurality of particles attached to the outer surface is 30% or less.

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