Coil component

Abstract

To provide a coil component capable of securing coil characteristics while suppressing a short circuit in a pair of terminal electrodes.SOLUTION: In a coil component 1, an element body 2 includes: a first portion 20 including a main surface 2d and a region between a pair of terminal electrodes 3, 4 in a second direction D2; a second portion 21 between the first portion 20 and a coil conductor layer located closest to the main surface 2d in a first direction D1; a third portion 22 between a coil conductor layer located closest to a main surface 2c and the coil conductor layer located closest to the main surface 2d in the first direction D1, the third portion 22 excluding a region between the conductor layers facing each other in the first direction D1; and a fourth portion 23 between the main surface 2c and the third portion 22 in the first direction D1, the fourth portion including the main surface 2c. The average particle diameter of metal magnetic particles in the first portion 20 is smaller than that in any of the second portion 21, the third portion 22, and the fourth portion 23.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a coil component. [Background technology]

[0002] The coil component includes an element body, a coil disposed inside the element body, and a pair of terminal electrodes disposed on the mounting surface of the element body and connected to the coil (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-141079 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a coil component that can ensure coil characteristics while suppressing short circuits between a pair of terminal electrodes. [Means for solving the problem]

[0005] (1) A coil component according to one aspect of the present invention is formed containing a plurality of metal magnetic particles of a soft magnetic material. The coil component comprises: an element body having a mounting surface and a main surface that face each other in a first direction; a pair of terminal electrodes that are exposed on the mounting surface and arranged facing each other in a second direction; and a coil that is arranged within the element body and is composed of a plurality of coil conductors. The element body includes: a first portion that includes the mounting surface and includes a region between the pair of terminal electrodes in the second direction; a second portion between the first portion and the coil conductor closest to the mounting surface in the first direction; a third portion between the coil conductor closest to the main surface and the coil conductor closest to the mounting surface in the first direction, the third portion not including a region between the coil conductors facing each other in the first direction; and a fourth portion that includes the main surface and is between the main surface and the third portion in the first direction. The average particle size of the metal magnetic particles in the first portion is smaller than the average particle size of the metal magnetic particles in any of the second, third, and fourth portions.

[0006] In a coil component according to one aspect of the present invention, the average particle size of the metal magnetic particles in the first portion is smaller than the average particle size of the metal magnetic particles in any of the second, third, and fourth portions. This allows the number of metal magnetic particles present between the pair of terminal electrodes to be increased compared to other portions. Therefore, the coil component can ensure a sufficient number of interfaces between the metal magnetic particles present between the pair of terminal electrodes, thereby improving the withstand voltage between the pair of terminal electrodes. Therefore, the coil component can suppress short circuits between the pair of terminal electrodes.

[0007] In the coil component, the average particle size of the metal magnetic particles in any of the second, third, and fourth portions is larger than the average particle size of the metal magnetic particles in the first portion. This allows the coil component to ensure magnetic permeability in the second, third, and fourth portions. Therefore, the coil component can ensure inductance and maintain coil characteristics.

[0008] (2) In the coil component of (1) above, at least a portion of each of the pair of terminal electrodes may be disposed inside the element body.

[0009] (3) In the coil component of (1) or (2), the first dimension of the first portion in the first direction may be larger than the second dimension of the terminal electrode in the first direction. This configuration ensures a sufficient number of interfaces between the metal magnetic particles present between the pair of terminal electrodes arranged inside the element body. Therefore, in the coil component, when the pair of terminal electrodes are arranged inside the element body, the withstand voltage between the pair of terminal electrodes can be improved.

[0010] (4) In the coil component of (3) above, the first dimension may be no more than twice the second dimension. If the first dimension of the first portion is greater than twice the second dimension, the magnetic permeability of the element body may decrease. In the coil component, by making the first dimension of the first portion no more than twice the second dimension, it is possible to ensure coil characteristics while suppressing short circuits between the pair of terminal electrodes.

[0011] (5) In the coil component of any one of (1) to (4), the first portion may be provided between each of the pair of terminal electrodes and the coil in the first direction. With this configuration, it is possible to suppress the generation of stray capacitance between each of the pair of terminal electrodes and the coil.

[0012] (6) In any one of the coil components (1) to (5), the first portion may include a region that, when viewed from the first direction, is equal to or larger than the dimensions of the terminal electrodes in a third direction perpendicular to the second direction. This configuration can further improve the withstand voltage between the pair of terminal electrodes. Therefore, the coil component can further suppress short circuits between the pair of terminal electrodes.

[0013] (7) In any one of the coil components (1) to (6) above, the first portion may include the entire area between the pair of terminal electrodes in the second direction when viewed from the first direction. This configuration can further improve the withstand voltage between the pair of terminal electrodes. Therefore, the coil component can further suppress short circuits between the pair of terminal electrodes.

[0014] (8) In any one of the coil components (1) to (7), the first portion may include a region surrounding the terminal electrodes. This configuration can further improve the withstand voltage between the pair of terminal electrodes. Therefore, the coil component can further suppress short circuits between the pair of terminal electrodes.

[0015] (9) In the coil component of any one of (1) to (8) above, in the first portion, some of the metal magnetic particles located around the terminal electrode may be embedded in the terminal electrode. This configuration ensures adhesion between the element body and the terminal electrode.

[0016] (10) In the coil component of (9), the first portion of the metal magnetic particles may include regular particles having an ellipsoidal shape and flat particles having an ellipsoidal shape that is flatter in the thickness direction than the regular particles, and some of the flat particles may be embedded in the terminal electrode such that the longitudinal direction of the flat particles intersects with the outer surface of the terminal electrode. This configuration ensures close contact between the element body and the terminal electrode. [Effects of the Invention]

[0017] According to one aspect of the present invention, it is possible to ensure coil characteristics while suppressing short circuits between a pair of terminal electrodes. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a coil component according to one embodiment. [Figure 2] FIG. 2 is a see-through perspective view of the coil component shown in FIG. [Figure 3] FIG. 3 is an exploded perspective view of the coil component. [Figure 4] FIG. 4 is a diagram showing a cross-sectional configuration taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a view of the coil component as seen from the main surface side. [Figure 6] FIG. 6(a) is a diagram showing the metal magnetic particles in the first portion, and FIG. 6(b) is a diagram showing the metal magnetic particles in the second portion, the third portion, and the fourth portion. [Figure 7] 7(a), 7(b), 7(c), and 7(d) are views of coil components according to other embodiments as viewed from the main surface side. [Figure 8] 8(a), 8(b), 8(c), and 8(d) are views of coil components according to other embodiments as viewed from the main surface side. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted.

[0020] The coil component will be described with reference to Figures 1 and 2. Figure 1 is a perspective view of a coil component according to one embodiment. Figure 2 is a see-through perspective view of the coil component shown in Figure 1. As shown in Figures 1 and 2, the coil component 1 includes an element body 2, terminal electrodes 3 and 4, a coil 5, a first connecting conductor 6 and a second connecting conductor 7. In Figure 2, the element body 2 is indicated by a dashed line.

[0021] The element body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 has, as its outer surfaces, a pair of end faces 2a and 2b, a pair of main faces 2c and 2d, and a pair of side faces 2e and 2f. The end faces 2a and 2b face each other. The main faces 2c and 2d face each other. The side faces 2e and 2f face each other. Hereinafter, the facing direction of the main faces 2c and 2d is referred to as a first direction D1, the facing direction of the end faces 2a and 2b is referred to as a second direction D2, and the facing direction of the side faces 2e and 2f is referred to as a third direction D3. The first direction D1, the second direction D2, and the third direction D3 are approximately perpendicular to each other.

[0022] The end faces 2a, 2b extend in the first direction D1 to connect the principal faces 2c, 2d. The end faces 2a, 2b also extend in the third direction D3 to connect the side faces 2e, 2f. The principal faces 2c, 2d extend in the second direction D2 to connect the end faces 2a, 2b. The principal faces 2c, 2d also extend in the third direction D3 to connect the side faces 2e, 2f. The side faces 2e, 2f extend in the first direction D1 to connect the principal faces 2c, 2d. The side faces 2e, 2f also extend in the second direction D2 to connect the end faces 2a, 2b.

[0023] The main surface 2d is a mounting surface that faces another electronic device (not shown) when the coil component 1 is mounted on the other electronic device (for example, a circuit board or a laminated electronic component). The end surfaces 2a and 2b are surfaces that are continuous with the mounting surface (i.e., the main surface 2d).

[0024] The length of the element body 2 in the second direction D2 is longer than the length of the element body 2 in the first direction D1 and the length of the element body 2 in the third direction D3. The length of the element body 2 in the third direction D3 is longer than the length of the element body 2 in the first direction D1. That is, in this embodiment, the end faces 2a, 2b, main faces 2c, 2d, and side faces 2e, 2f have a rectangular shape. The length of the element body 2 in the first direction D1 may be equal to or shorter than the length of the element body 2 in the third direction D3.

[0025] In this embodiment, "equivalent" does not only mean equal, but also may mean values ​​that include slight differences or manufacturing errors within a preset range. For example, if multiple values ​​are within a range of ±5% of the average value of the multiple values, the multiple values ​​are defined as equivalent.

[0026] The element body 2 is formed by stacking a plurality of element body layers (insulator layers) 10a-10g (see FIG. 3) in a first direction D1. That is, the stacking direction of the element body 2 is the first direction D1. The specific stacking configuration will be described later. In the actual element body 2, the plurality of element body layers 10a-10g are integrated to the extent that the boundaries between the layers are not visible.

[0027] The base layers 10a-10g contain a plurality of metal magnetic grains P1, P2 (see FIGS. 6(a) and 6(b)). The metal magnetic grains P1, P2 are made of a soft magnetic alloy (soft magnetic material). The soft magnetic alloy is, for example, an Fe-Si alloy. When the soft magnetic alloy is an Fe-Si alloy, it may contain P. The soft magnetic alloy may be, for example, an Fe-Ni-Si-M alloy. "M" includes one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare earth elements.

[0028] In the element body 2, the metal magnetic particles are bonded to each other. The bond between the metal magnetic particles is realized, for example, by bonding between oxide films (not shown) formed on the surfaces of the metal magnetic particles. The thickness of the oxide film is, for example, 5 nm or more and 60 nm or less. The oxide film may be composed of one or more layers.

[0029] The terminal electrodes 3 and 4 are each provided on the element body 2. The terminal electrodes 3 and 4 are each arranged on the main surface 2d of the element body 2. The terminal electrodes 3 and 4 are provided on the element body 2 and spaced apart from each other in the second direction D2. Specifically, the terminal electrode 3 is arranged on the end surface 2a side of the element body 2. The terminal electrode 4 is arranged on the end surface 2b side of the element body 2. The terminal electrodes 3 and 4 are embedded in the element body 2. In this embodiment, the surfaces of the terminal electrodes 3 and 4 are approximately flush with the main surface 2d.

[0030] Each of the terminal electrodes 3 and 4 is made of a conductive material such as Cu, Ni, Sn, or Au. In this embodiment, each of the terminal electrodes 3 and 4 is a plated electrode (plated conductor) formed by plating (electrolytic plating or electroless plating). Each of the terminal electrodes 3 and 4 may have a single-layer structure or a multi-layer structure.

[0031] The coil 5 is disposed within the element body 2. The coil 5 is composed of a plurality of coil conductor layers (coil conductors) 12a to 12e (see FIG. 3). The plurality of coil conductor layers 12a to 12e are electrically connected to each other to form the coil 5 within the element body 2. The coil axis of the coil 5 is provided along the first direction D1. The coil conductor layers 12a to 12e are disposed so as to at least partially overlap each other when viewed from the first direction D1. The plurality of coil conductor layers 12b to 12e are made of a conductive material (for example, Ag or Pd). In this embodiment, the plurality of coil conductor layers 12a, 12c, and 12e are plated conductors. The coil conductor layers 12a to 12e are disposed spaced apart from the end faces 2a and 2b, the main faces 2c and 2d, and the side faces 2e and 2f.

[0032] The first connecting conductor 6 is disposed within the element body 2. The first connecting conductor 6 connects the terminal electrode 3 and the coil 5. The first connecting conductor 6 is a through-hole conductor. The first connecting conductor 6 extends in a first direction D1 and is connected to the terminal electrode 3 and one end of the coil 5. The first connecting conductor 6 is composed of a plurality of first connecting conductor layers 14a (see FIG. 3). In this embodiment, the first connecting conductor 6 has a rectangular cross section (cross section along the second direction D2 and the third direction D3) perpendicular to the extending direction (first direction D1). That is, the first connecting conductor 6 has a prismatic shape.

[0033] The second connecting conductor 7 is disposed within the element body 2. The second connecting conductor 7 connects the terminal electrode 4 and the coil 5. The second connecting conductor 7 is a through-hole conductor. The second connecting conductor 7 extends in the first direction D1 and is connected to the terminal electrode 4 and the other end of the coil 5. The second connecting conductor 7 is composed of a plurality of second connecting conductor layers 16a, 16b, 16c, 16d, and 16e (see FIG. 3). In this embodiment, the second connecting conductor 7 has a rectangular cross section (cross section along the second direction D2 and the third direction D3) perpendicular to the extension direction (first direction D1). That is, the second connecting conductor 7 has a prismatic shape.

[0034] Fig. 3 is an exploded perspective view of the coil component shown in Fig. 1. As shown in Fig. 3, the coil component 1 includes a plurality of layers La, Lb, Lc, Ld, Le, Lf, and Lg. The coil component 1 is configured, for example, by stacking the layers La to Lg in order from the main surface 2c side. The coil component 1 according to this embodiment includes a plurality of layers Lc and a plurality of layers Lg.

[0035] The layer La is composed of the element body layer 10a. The layer La forms the main surface 2c of the element body 2.

[0036] Layer Lb is formed by combining an element layer 10b and a coil conductor layer 12a. The element layer 10b has a shape corresponding to the coil conductor layer 12a and is provided with a recess (not shown) into which the coil conductor layer 12a is fitted. The element layer 10b and the coil conductor layer 12a have a complementary relationship.

[0037] The layer Lc is formed by combining an element layer 10c, a coil conductor layer 12b, and a second connecting conductor layer 16a. The element layer 10c has shapes corresponding to the coil conductor layer 12b and the second connecting conductor layer 16a, and is provided with recesses (not shown) into which the coil conductor layer 12b and the second connecting conductor layer 16a are fitted. The element layer 10c and the entire coil conductor layer 12b and second connecting conductor layer 16a have a complementary relationship.

[0038] The layer Ld is formed by combining an element layer 10d, a coil conductor layer 12c, and a second connecting conductor layer 16b. The element layer 10d has shapes corresponding to the coil conductor layer 12c and the second connecting conductor layer 16b, and is provided with recesses (not shown) into which the coil conductor layer 12c and the second connecting conductor layer 16b are fitted. The element layer 10d and the coil conductor layer 12c and the second connecting conductor layer 16b as a whole have a complementary relationship with each other.

[0039] The layer Le is formed by combining an element layer 10e, a coil conductor layer 12d, and a second connecting conductor layer 16c. The element layer 10e has recesses (not shown) that have shapes corresponding to the coil conductor layer 12d and the second connecting conductor layer 16c and into which the coil conductor layer 12d and the second connecting conductor layer 16c are fitted. The element layer 10e and the coil conductor layer 12d and the second connecting conductor layer 16c as a whole have a complementary relationship with each other.

[0040] The layer Lf is formed by combining an element layer 10f, a coil conductor layer 12e, and a second connecting conductor layer 16d. The element layer 10f has cutouts (not shown) that have shapes corresponding to the coil conductor layer 12e and the second connecting conductor layer 16d and into which the coil conductor layer 12e and the second connecting conductor layer 16d are fitted. The element layer 10f and the entire coil conductor layer 12e and second connecting conductor layer 16d have a complementary relationship.

[0041] The layer Lg is formed by combining an element body layer 10g, a first connecting conductor layer 14a, and a second connecting conductor layer 16e. The element body layer 10g has shapes corresponding to the first connecting conductor layer 14a and the second connecting conductor layer 16e, and is provided with recesses (not shown) into which the first connecting conductor layer 14a and the second connecting conductor layer 16e are fitted. The element body layer 10g and the entire first connecting conductor layer 14a and the second connecting conductor layer 16e have a complementary relationship with each other. The layer Lg forms the main surface 2d of the element body 2.

[0042] Fig. 4 is a diagram showing a cross-sectional configuration taken along line IV-IV in Fig. 1. As shown in Fig. 4, the element body 2 includes a first portion 20, a second portion 21, a third portion 22, and a fourth portion 23. The first portion 20, the second portion 21, the third portion 22, and the fourth portion 23 are located in this order from the main surface 2d toward the main surface 2c.

[0043] The first portion 20 is a portion that includes the main surface 2d and also includes a region A (see FIG. 5) between the terminal electrodes 3 and 4 in the second direction D2. As shown in FIG. 5, the first portion 20 includes a region A that is equal to or larger than the dimension W of the terminal electrodes 3 and 4 in the third direction D3 when viewed from the first direction D1. The first portion 20 includes the entire region A between the pair of terminal electrodes 3 and 4 in the second direction D2 when viewed from the first direction D1. In this embodiment, the first portion 20 includes the entire region A of the main surface 2d.

[0044] 4, the first portion 20 includes the regions surrounding the terminal electrode 3 and the terminal electrode 4. The first portion 20 is provided between the terminal electrode 3 and the coil 5 (coil conductor layer 12e) and each of the terminal electrodes 3 and 4 in the first direction D1. A first dimension T1 of the first portion 20 in the first direction D1 is larger than a second dimension T2 of the terminal electrodes 3 and 4 in the first direction D1 (T1>T2). It is preferable that the first dimension T1 be equal to or smaller than twice the second dimension T2.

[0045] The second portion 21 is a portion between the first portion 20 and the coil conductor layer 12e located closest to the main surface 2d in the first direction D1.

[0046] The third portion 22 is a portion in the first direction D1 between the coil conductor layer 12a located closest to the principal surface 2c and the coil conductor layer 12e located closest to the principal surface 2d. Specifically, the third portion 22 is a portion in the first direction D1 between the surface of the coil conductor layer 12a facing the principal surface 2c and the surface of the coil conductor layer 12e facing the principal surface 2d. The third portion 22 does not include a region between the coil conductor layers facing each other in the first direction D1. Specifically, the third portion 22 does not include a region between the coil conductor layer 12a and the coil conductor layer 12c facing each other in the first direction D1, or a region between the coil conductor layer 12c and the coil conductor layer 12e facing each other in the first direction D1.

[0047] The fourth portion 23 includes the main surface 2c and is a portion between the main surface 2c and the third portion 22 in the first direction D1.

[0048] In the coil device 1, the average particle size of the metal magnetic particles P1 (FIG. 6(a)) in the first portion 20 is smaller than the average particle size of the metal magnetic particles P2 (FIG. 6(b)) in any of the second portion 21, the third portion 22, and the fourth portion 23. In this embodiment, the average particle size of the metal magnetic particles P1 in the first portion 20 is smaller than the average particle size of the metal magnetic particles P2 in the second portion 21, the third portion 22, and the fourth portion 23. In this embodiment, the particle size is defined by the circle-equivalent diameter. The circle-equivalent diameter of the metal magnetic particles P1 and P2 can be obtained, for example, as follows.

[0049] A cross-sectional photograph of the coil component 1 is obtained. The obtained cross-sectional photograph is subjected to image processing using software. The boundaries of the metal magnetic particles P1 and P2 are identified through image processing, and the areas of the metal magnetic particles P1 and P2 are determined. From the determined areas of the metal magnetic particles P1 and P2, the particle diameters converted into circle-equivalent diameters are determined. Here, the particle diameters of 100 or more metal magnetic particles P1 and P2 are calculated, and the particle size distribution of these metal magnetic particles P1 and P2 is determined. The particle diameter (d50) at 50% of the cumulative value in the determined particle size distribution is defined as the "average particle diameter." There are no particular restrictions on the particle shape of the metal magnetic particles P1 and P2.

[0050] As shown in FIG. 6(a), the metal magnetic particles P1 are specifically composed of regular particles P11 each having an ellipsoidal shape and flat particles P12 each having an ellipsoidal (disk-shaped) shape that is flatter in the thickness direction than the regular particles. The thickness direction is a direction defined for convenience. Regular particles P11 have a surface including a major axis direction and a minor axis direction perpendicular to the thickness direction. Similarly, flat particles P12 have a surface including a major axis direction and a minor axis direction perpendicular to the thickness direction. For example, particles whose major axis direction perpendicular to the thickness direction is three times or less than the thickness direction length are considered regular particles P11, and particles whose major axis direction perpendicular to the thickness direction is more than three times the thickness direction length are considered flat particles P12.

[0051] The regular particles P11 and the flat particles P12 each have a major axis and a minor axis when viewed from a direction perpendicular to the thickness direction and when viewed from the thickness direction. Regarding the relationship between the regular particles P11 and the flat particles P12, the major axis of the regular particles P11 is smaller than the major axis of the flat particles P12, and the minor axis of the regular particles P11 is larger than the minor axis of the flat particles P12. The volume of the regular particles P11 is larger than the volume of the flat particles P12. The volume of the regular particles P11 may be more than twice the volume of the flat particles P12.

[0052] A scanning electron microscope (SEM), for example, can be used to measure the minor and major axes and the volume of the regular particles P11 and flat particles P12. In this case, a cross-sectional photograph of the element body 2 is taken using the SEM, and the particle diameter and minor axis are measured by elliptical approximation of the particle cross section. The volume is calculated based on the average particle diameters of the regular particles P11 and flat particles P12 present in each cross section perpendicular to the first direction D1, the second direction D2, and the third direction D3 in a predetermined region of the element body 2.

[0053] Some of the regular particles P11 and flat particles P12 arranged around the terminal electrode 3 (terminal electrode 4) are embedded in the terminal electrode 3 (terminal electrode 4). Being embedded in the terminal electrode 3 (terminal electrode 4) can be said to be sinking in, intruding, pushing in, or biting into. The flat particles P12 are embedded in the terminal electrode 3 (terminal electrode 4) so ​​that their major diameters (longitudinal direction) intersect with the outer surface 3a (outer surface 4a) of the terminal electrode 3 (terminal electrode 4).

[0054] As described above, in the coil component 1 according to this embodiment, the average particle size of the metal magnetic particles P1 in the first portion 20 of the element body 2 is smaller than the average particle size of the metal magnetic particles P2 in the second portion 21, the third portion 22, and the fourth portion 23. This makes it possible to increase the number of metal magnetic particles P1 present between the pair of terminal electrodes 3, 4 in the coil component 1 compared to the second portion 21, the third portion 22, and the fourth portion 23. Therefore, in the coil component 1, it is possible to ensure a sufficient number of interfaces of the metal magnetic particles P1 present between the pair of terminal electrodes 3, 4, and to improve the withstand voltage between the pair of terminal electrodes 3, 4. Therefore, in the coil component 1, it is possible to suppress short circuits between the pair of terminal electrodes 3, 4.

[0055] In coil device 1, the average particle size of metal magnetic particles P2 in second portion 21, third portion 22, and fourth portion 23 of element body 2 is larger than the average particle size of metal magnetic particles P1 in first portion 20. This ensures that coil device 1 has sufficient magnetic permeability in second portion 21, third portion 22, and fourth portion 23 of element body 2. Therefore, coil device 1 can ensure sufficient inductance and maintain coil characteristics.

[0056] In the coil component 1 according to this embodiment, the first dimension T1 of the first portion 20 of the element body 2 in the first direction D1 is larger than the second dimension T2 of the terminal electrodes 3, 4 in the first direction D1. This configuration ensures a sufficient number of interfaces of the metal magnetic particles P1 present between the pair of terminal electrodes 3, 4 arranged inside the element body 2. Therefore, in the coil component 1, in a configuration in which the pair of terminal electrodes 3, 4 are arranged inside the element body 2, the withstand voltage between the pair of terminal electrodes 3, 4 can be improved.

[0057] In the coil component 1 according to this embodiment, the first dimension T1 of the first portion 20 may be equal to or less than twice the second dimension T2 of the terminal electrodes 3 and 4. If the first dimension T1 of the first portion 20 is greater than twice the second dimension T2, the magnetic permeability of the element body 2 may decrease. In the coil component 1, by setting the first dimension T1 of the first portion 20 to be equal to or less than twice the second dimension T2, it is possible to ensure coil characteristics while suppressing short circuits between the pair of terminal electrodes.

[0058] In the coil component 1 according to this embodiment, the first portion 20 of the element body 2 is provided in the first direction D1 between each of the pair of terminal electrodes 3, 4 and the coil 5. With this configuration, it is possible to suppress the generation of stray capacitance between each of the pair of terminal electrodes 3, 4 and the coil 5.

[0059] In the coil component 1 according to this embodiment, the first portion 20 of the element body 2 includes the entire region between the pair of terminal electrodes 3, 4 in the second direction D2 when viewed from the first direction D1. This configuration can further improve the withstand voltage between the pair of terminal electrodes 3, 4. Therefore, in the coil component 1, short circuits between the pair of terminal electrodes 3, 4 can be further suppressed.

[0060] In the coil component 1 according to this embodiment, in the first portion 20 of the element body 2, some of the metal magnetic particles P1 located around the terminal electrodes 3, 4 are embedded in the terminal electrodes 3, 4. With this configuration, adhesion between the element body 2 and the terminal electrodes 3, 4 can be ensured.

[0061] In the coil component 1 according to this embodiment, in the first portion 20 of the element body 2, the metal magnetic particles P1 include regular particles P11 each having an ellipsoidal shape and flat particles P12 each having an ellipsoidal shape that is flatter in the thickness direction than the regular particles P11. Some of the flat particles P12 are embedded in the terminal electrode 3 (terminal electrode 4) so ​​that the major axis of the flat particles P12 intersects with the outer surface 3a (4a) of the terminal electrode 3 (terminal electrode 4). This configuration ensures close contact between the element body 2 and the terminal electrodes 3 and 4.

[0062] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0063] In the above embodiment, an example has been described in which the terminal electrodes 3 and 4 are each embedded in the element body 2. Specifically, in the above embodiment, an example has been described in which the surfaces of the terminal electrodes 3 and 4 are each substantially flush with the main surface 2d. However, the terminal electrodes may be at least partially embedded in the element body 2, or may be disposed on the main surface 2d. It is sufficient that the terminal electrodes 3 and 4 are each located so as to be exposed to the main surface 2d.

[0064] In the above embodiment, the terminal electrodes 3 and 4 each have a rectangular shape when viewed from the first direction D1. However, the shapes of the terminal electrodes 3 and 4 are not limited to these and may be other shapes (circular, elliptical, polygonal, etc.).

[0065] In the above embodiment, the first dimension T1 in the first direction D1 of the first portion 20 is larger than the second dimension T2 in the first direction D1 of the terminal electrodes 3 and 4 (T1>T2). However, the first dimension T1 may be smaller than the second dimension T2.

[0066] In the above embodiment, an example has been described in which the first portion 20 is provided around each of the terminal electrodes 3 and 4. However, the first portion does not have to be provided around each of the terminal electrodes 3 and 4.

[0067] In the above embodiment, the first portion 20 includes the entire region A of the main surface 2d. However, the first portion 20 may include at least a part of the region A between the pair of terminal electrodes 3, 4 in the second direction D2.

[0068] As shown in Fig. 7(a), the first portion 20 may include a portion of the region A between the pair of terminal electrodes 3 and 4, or as shown in Fig. 7(b), the first portion 20 may be U-shaped (channel-shaped) so as to include a portion of the region A between the pair of terminal electrodes 3 and 4. As shown in Fig. 7(c), the first portion 20 may be H-shaped so as to include a portion of the region A between the pair of terminal electrodes 3 and 4, or as shown in Fig. 7(d).

[0069] As shown in Fig. 8(a), the first portion 20 may include only the region A between the pair of terminal electrodes 3, 4, or as shown in Fig. 8(b), the first portion 20 may have a frame shape surrounding the periphery of the terminal electrodes 3, 4 so as to include a portion of the region A between the pair of terminal electrodes 3, 4. As shown in Fig. 8(c), the first portion 20 may have a form that includes the region A between the pair of terminal electrodes 3, 4 but does not include the edge portion of the main surface 2d, or as shown in Fig. 8(d), the first portion 20 may include multiple regions A between the pair of terminal electrodes 3, 4. [Explanation of symbols]

[0070] 1...coil component, 2...element body, 2c, 2d...main surface (mounting surface), 3...terminal electrode, 3a...outer surface, 4...terminal electrode, 4a...outer surface, 5...coil, 12a, 12c, 12e...coil conductor layer (coil conductor), 20...first portion, 21...second portion, 22...third portion, 23...fourth portion, A...region, D1...first direction, D2...second direction, D3...third direction, P1...metal magnetic particle, P2...metal magnetic particle, P11...normal particle, P12...flat particle, T1...first dimension, T2...second dimension, W...dimension.

Claims

1. an element body formed including a plurality of metal magnetic particles of a soft magnetic material, the element body having a mounting surface and a main surface that face each other in a first direction; a pair of terminal electrodes positioned to be exposed on the mounting surface and facing each other in the second direction; a coil disposed within the element body and composed of a plurality of coil conductors; The element body is a first portion including the mounting surface and an area between the pair of terminal electrodes in the second direction; a second portion between the first portion and the coil conductor located closest to the mounting surface in the first direction; a third portion between the coil conductor closest to the main surface and the coil conductor closest to the mounting surface in the first direction, the third portion not including a region between the coil conductors facing each other in the first direction; a fourth portion including the main surface and between the main surface and the third portion in the first direction, A coil component, wherein the average particle size of the metal magnetic particles in the first portion is smaller than the average particle size of the metal magnetic particles in any of the second portion, the third portion, and the fourth portion.

2. The coil component according to claim 1 , wherein at least a portion of each of the pair of terminal electrodes is disposed inside the element body.

3. The coil component according to claim 1 , wherein a first dimension of the portion in the first direction is larger than a second dimension of the terminal electrode in the first direction.

4. The coil component according to claim 3 , wherein the first dimension is equal to or smaller than twice the second dimension.

5. The coil component according to claim 1 , wherein the first portion is provided between each of the pair of terminal electrodes and the coil in the first direction.

6. The coil component according to claim 1 , wherein the first portion includes an area that is equal to or larger than a dimension of the terminal electrode in a third direction orthogonal to the second direction, as viewed from the first direction.

7. The coil component according to claim 1 , wherein the first portion includes, when viewed from the first direction, the entire region between the pair of terminal electrodes in the second direction.

8. The coil component according to claim 1 , wherein the first portion includes a region surrounding the terminal electrode.

9. The coil component according to claim 1 , wherein in the first portion, a part of the metal magnetic particles located around the terminal electrode is embedded in the terminal electrode.

10. In the first portion, the metal magnetic particles include regular particles having an ellipsoidal shape and flat particles having an ellipsoidal shape that is flatter in the thickness direction than the regular particles, The coil component according to claim 9 , wherein some of the flat particles are embedded in the terminal electrode such that the longitudinal direction of the flat particles intersects with the outer surface of the terminal electrode.

Images