Inductor part

Abstract

Provided is an inductor part having improved heat dissipation. The inductor part includes a unit body and a coil provided in the unit body; the unit body contains a resin containing metal magnetic powder, the resin containing metal magnetic powder including a resin and metal magnetic powder contained in the resin; the unit body has a cuboid shape, and has a first main surface and a second main surface that face each other, and a first side surface, a second side surface, a third side surface, and a fourth side surface that connect the first main surface and the second main surface; the first main surface and the second main surface each have an area that is larger than an area of each of the first to fourth side surfaces; one or more recesses are provided in the first side surface and the first main surface, respectively; and a maximum depth of the deepest recess of the one or more recesses of the first side surface is greater than a maximum depth of the deepest recess of the one or more recesses of the first main surface.

Description

Technical Field

[0001] This invention relates to inductor components. Background Technology

[0002] To date, the component described in Japanese Patent No. 6024243 (Patent Document 1) can be cited as an example of an inductor component. This inductor component includes a unit body and a coil disposed within the unit body; the unit body comprises a resin containing metallic magnetic powder, and the resin containing metallic magnetic powder has resin and metallic magnetic powder contained in the resin.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6024243 Summary of the Invention

[0006] However, in existing inductor components, self-heating caused by internal resistive losses, eddy current losses, etc., is released to the outside from the main surface and sides of the component, as well as the exposed conductors used for bonding during component mounting. However, the heat released from the main surface and sides of the component is limited by the surface area of ​​the unit cell; therefore, there is still room for improvement in the heat dissipation of existing inductor components.

[0007] Therefore, the objective of this invention is to provide an inductor component that improves heat dissipation.

[0008] To solve the above-mentioned problems, an inductor component according to one aspect of the present invention comprises:

[0009] unit body, and

[0010] The coil is disposed within the aforementioned unit body;

[0011] The aforementioned unit comprises a resin containing metallic magnetic powder, wherein the resin containing metallic magnetic powder has the resin and the metallic magnetic powder contained in the resin.

[0012] The above-mentioned unit body is in the shape of a cuboid, which has: a first main face and a second main face that are opposite to each other, and a first side face, a second side face, a third side face and a fourth side face that are connected to the first main face and the second main face.

[0013] The areas of the first and second main surfaces are each larger than the areas of the first to fourth side surfaces.

[0014] One or more recesses are provided on the first side surface and the first main surface, respectively.

[0015] The maximum depth of the deepest recess among the one or more recesses on the first side surface is greater than the maximum depth of the deepest recess among the one or more recesses on the first main surface.

[0016] Here, when there is only one recess in the first side surface, "the maximum depth of the deepest recess among the one or more recesses on the first side surface" refers to the maximum depth of the recess in a direction orthogonal to the line segment connecting the two opening ends of the recess on the first side surface, within a cross-section of a plane containing the center of the unit body and orthogonal to the first main surface and the first side surface. When there are multiple recesses on the first side surface, "the maximum depth of the deepest recess among the one or more recesses on the first side surface" refers to the maximum value of the depth of each recess in a direction orthogonal to the line segment connecting the two opening ends of the recess on the first side surface, within a cross-section of a plane containing the center of the unit body and orthogonal to the first main surface and the first side surface. It should be noted that in the following description, "the maximum depth of the deepest recess among the one or more recesses on the first side surface" is sometimes simply referred to as "the maximum depth of the recess on the first side surface".

[0017] Similarly, when there is only one recess in the first main surface, "the maximum depth of the deepest recess among the one or more recesses of the first main surface" refers to the maximum depth of the recess in a direction orthogonal to the line segment connecting the two opening ends of the recess of the first main surface, within a cross-section of a plane containing the center of the unit body and orthogonal to the first main surface and the first side surface. When there are multiple recesses in the first main surface, "the maximum depth of the deepest recess among the one or more recesses of the first main surface" refers to the maximum value on the first main surface among the maximum depths of each recess in a direction orthogonal to the line segment connecting the two opening ends of the recess of the first main surface, within a cross-section of a plane containing the center of the unit body and orthogonal to the first main surface and the first side surface. It should be noted that in the following description, "the maximum depth of the deepest recess among the one or more recesses of the first main surface" is sometimes simply referred to as "the maximum depth of the recess of the first main surface".

[0018] According to the inductor component of the present invention, recesses are provided on the first side surface and the second main surface. Therefore, the surface area of ​​the unit body is increased, which improves the heat dissipation of the inductor component.

[0019] Furthermore, in the inductor component according to the present invention, in thin components, the maximum depth of the recess on the first side surface is greater than the maximum depth of the recess on the first main surface. Therefore, the reduction in unit strength caused by the recess can be suppressed, and the surface area of ​​the side surface of the unit can be increased. As a result, the heat dissipation of the inductor component can be improved without reducing the unit strength.

[0020] Furthermore, in the inductor component according to the present invention, the maximum depth of the recess on the first side surface is greater than the maximum depth of the recess on the first main surface. Therefore, when a directional identification mark is provided on the first main surface, the heat dissipation of the inductor component is improved without reducing the resolution during image recognition.

[0021] In another embodiment of the inductor component,

[0022] The first side is opposite to the third side.

[0023] The second side is opposite to the fourth side.

[0024] The distance between the first main surface and the second main surface is shorter than the distance between the first side surface and the third side surface and the distance between the second side surface and the fourth side surface.

[0025] According to the above embodiments, inductor components can be further thinned.

[0026] In another embodiment of the inductor component,

[0027] One or more recesses are provided on the second main surface mentioned above.

[0028] The maximum depth of the deepest recess among the one or more recesses on the first side surface is greater than the maximum depth of the deepest recess among the one or more recesses on the second main surface.

[0029] According to the above embodiment, the maximum depth of the recess on the first side is greater than the maximum depth of the recess on the second main side. Therefore, heat dissipation can be improved more effectively without reducing the strength of the unit body.

[0030] In another embodiment of the inductor component,

[0031] One or more recesses are provided on each of the second to fourth side surfaces.

[0032] The maximum depth of the deepest recess among the one or more recesses on each of the second to fourth sides is greater than the maximum depth of the deepest recess among the one or more recesses on the first main surface.

[0033] According to the above embodiment, the surface area of ​​the side of the unit body can be further increased, thereby further improving the heat dissipation of the side of the unit body. In addition, since the recesses are provided on all four sides of the first to fourth sides, the maximum depth of the recesses can be controlled on each side of each unit body, thereby controlling the distribution of heat generated from the side of the part.

[0034] In another embodiment of the inductor component,

[0035] The distance between the first principal surface and the second principal surface is less than 300 μm.

[0036] According to the above embodiments, heat dissipation can be improved in thin parts where the distance between the first main surface and the second main surface is less than 300 μm.

[0037] In another embodiment of the inductor component,

[0038] The resin containing the aforementioned metallic magnetic powder is exposed on the first side.

[0039] All of the aforementioned recesses on the first side are provided on the exposed surface of the resin containing the metallic magnetic powder.

[0040] The resin containing metallic magnetic powder has high thermal conductivity. According to the above embodiment, all the recesses on the first side are provided on the exposed surface of the resin containing metallic magnetic powder, thus improving the heat dissipation of the inductor components more effectively.

[0041] In another embodiment of the inductor component,

[0042] The inner surface of at least one of the above-mentioned recesses on the first side is hemispherical.

[0043] According to the above embodiment, the inner surface of at least one recess is hemispherical, so the mechanical stress is dispersed on the inner surface of the recess, which can ensure the strength of the unit body.

[0044] In another embodiment of the inductor component,

[0045] The inner surface of at least one of the one or more recesses on the first side is made of the resin contained in the resin containing the metallic magnetic powder.

[0046] Compared to the area outside the recess, the inner surface of the recess is more prone to mechanical stress concentration, making it more susceptible to defects such as cracks. According to the above embodiment, the inner surface of the recess on the first side is made of resin containing metallic magnetic powder. Therefore, even when mechanical stress is concentrated on the inner surface of the recess, the generation of defects such as cracks can be suppressed, and the degradation of the characteristics and reliability of the inductor component can be prevented.

[0047] In another embodiment of the inductor component,

[0048] The aforementioned metallic magnetic powder contains iron.

[0049] The cut-off metallic magnetic powder is exposed on at least one of the first to fourth sides.

[0050] According to the above embodiment, the cut metal magnetic powder is exposed on at least one of the first to fourth sides, thereby further improving the heat dissipation of the side of the unit body.

[0051] In another embodiment of the inductor component,

[0052] When the maximum diameter of the exposed surface of the cut metal magnetic powder is set as D (μm) and the distance between the first main surface and the second main surface is set as T (μm), D ≥ 0.3T is satisfied.

[0053] Here, "the maximum diameter of the exposed surface of the cut metal magnetic powder" refers to the maximum value among the circular equivalent diameters of the exposed surfaces of the multiple cut metal magnetic powders exposed on at least one of the first to fourth sides.

[0054] According to the above embodiments, the maximum diameter of the exposed surface of the metal magnetic powder can be larger, thus further improving the heat dissipation of the side of the unit.

[0055] In another embodiment of the inductor component,

[0056] Further satisfy D≥10.

[0057] According to the above implementation method, the heat dissipation of the side of the unit can be improved more effectively.

[0058] In another embodiment of the inductor component,

[0059] An oxide film is formed on the exposed surface of the cut-off metallic magnetic powder.

[0060] Metallic magnetic powder is conductive; therefore, when the cut-off piece of metallic magnetic powder comes into contact with the external terminal of an adjacent component, current leakage can occur through the metallic magnetic powder. According to the above embodiment, an oxide film is formed on the exposed surface of the cut-off metallic magnetic powder. The oxide film increases the resistance of the metallic magnetic powder, thus improving the short-circuit withstand capability of the inductor component.

[0061] According to one aspect of the present invention, an inductor component can be realized that improves heat dissipation. Attached Figure Description

[0062] Figure 1 This is a perspective view showing the inductor component according to the first embodiment.

[0063] Figure 2 This is an exploded perspective view showing the inductor component according to the first embodiment.

[0064] Figure 3A for Figure 1 A-A' cross-sectional view.

[0065] Figure 3B for Figure 1 B-B' cross-section.

[0066] Figure 4A for Figure 3B An enlarged view of region A.

[0067] Figure 4B for Figure 3B A magnified view of region B.

[0068] Figure 5 A schematic cross-sectional view illustrating the composition of the region containing the main face and side faces of a unit cell.

[0069] Figure 6 An image representing the shape of the side of a unit cell.

[0070] Figure 7A An explanatory diagram illustrating the manufacturing method of the inductor component according to the first embodiment.

[0071] Figure 7B An explanatory diagram illustrating the manufacturing method of the inductor component according to the first embodiment.

[0072] Figure 7C An explanatory diagram illustrating the manufacturing method of the inductor component according to the first embodiment.

[0073] Figure 7D An explanatory diagram illustrating the manufacturing method of the inductor component according to the first embodiment.

[0074] Figure 7E An explanatory diagram illustrating the manufacturing method of the inductor component according to the first embodiment.

[0075] Figure 8 This is a cross-sectional view showing the inductor component according to the second embodiment.

[0076] Figure 9 This is a cross-sectional view showing the inductor component according to the third embodiment.

[0077] Figure 10 This is a cross-sectional view showing the inductor component according to the fourth embodiment.

[0078] Symbol Explanation

[0079] 10 unit cells

[0080] 11, 12 1st~2nd main surface

[0081] 13-16 Side Views (1st-4th)

[0082] 17. Resins containing metallic magnetic powder

[0083] 171 Resin

[0084] 172 Metal Magnetic Powder

[0085] 172F exposed face

[0086] 18 Insulating Resin

[0087] 20 coils

[0088] 201 Through-hole pad

[0089] 41, 42 external terminals

[0090] 51, 52 Lead-out wiring

[0091] 61 Through-hole wiring

[0092] 11R, 14R recessed parts

[0093] C Tangent

[0094] P is the cut-off metallic magnetic powder

[0095] e1~e4 Opening ends Detailed Implementation

[0096] The following is a detailed description of an inductor component as one embodiment of the present invention, illustrated in the figures. It should be noted that the figures are only partial and schematic, and may not reflect actual dimensions or ratios.

[0097] (First Embodiment)

[0098] (Overall Composition)

[0099] Figure 1 This is a perspective view showing the first embodiment of the inductor component. Figure 2 This is an exploded perspective view of an inductor component. Figure 3A for Figure 1 A-A' cross-sectional view. Figure 3B for Figure 1 The B-B' cross-sectional view. Specifically, Figure 3A It is a cross-section that includes the center of the unit and is parallel to the second and fourth sides of the unit. Figure 3B It is a cross-section that includes the center of the unit and is parallel to the first and third sides of the unit.

[0100] Inductor component 1 is, for example, a component with an overall rectangular shape, which can be mounted on electronic devices such as computers, DVD players, digital cameras, TVs, mobile phones, smartphones, and automotive electronics.

[0101] like Figures 1 to 3B As shown, the inductor component 1 includes: a unit body 10, a coil 20 disposed within the unit body 10, a first lead wire 51 electrically connected to a first end of the coil 20, a second lead wire 52 electrically connected to a second end of the coil 20, a first external terminal 41 disposed on the surface of the unit body 10 and electrically connected to the first lead wire 51, and a second external terminal 42 electrically connected to the second lead wire 52.

[0102] Unit 10 is a component that holds coil 20, first lead wire 51, and second lead wire 52. Unit 10 is a cuboid with opposing first main surfaces 11 and 2 main surfaces 12, and first to fourth side surfaces 13 to 16 connected to the first and second main surfaces 11 and 2 main surfaces 12. First side surface 13 is opposite to third side surface 15, and second side surface 14 is opposite to fourth side surface 16. As shown, the direction orthogonal to the first main surface 11 and 2 main surfaces 12 is defined as the Z direction (vertical direction). Hereinafter, the direction clockwise is defined as the upper side, and the direction counterclockwise is defined as the lower side. The direction orthogonal to the Z direction and to the second side surface 14 and fourth side surface 16 is defined as the X direction. The direction orthogonal to the Z direction and to the first side surface 13 and third side surface 15 is defined as the Y direction. Hereinafter, the X direction is referred to as the "length direction," the Y direction as the "width direction," and the Z direction as the "thickness direction." It should be noted that in this specification, "cuboid" refers not only to the case where the six faces are all orthogonal to each other, but also to the case where the faces intersect at angles that are slightly off-right.

[0103] The areas of the first main surface 11 and the second main surface 12 are each larger than the areas of the first to fourth side surfaces 13 to 16. That is, the inductor part 1 is a thin part with a thin thickness in the Z direction. Preferably, the distance between the first main surface 11 and the second main surface 12 is 300 μm or less. Preferably, the distance between the first main surface 11 and the second main surface 12 is more than twice the diameter of the metallic magnetic powder. For example, the distance between the first main surface 11 and the second main surface 12 is 50 μm or more. Preferably, the distance between the first main surface 11 and the second main surface 12 is shorter than the distance between the first side surface 13 and the third side surface 15 and the distance between the second side surface 14 and the fourth side surface 16.

[0104] Unit 10 comprises a resin 17 containing metallic magnetic powder, wherein the resin 17 contains both resin and the metallic magnetic powder contained in the resin. In this embodiment, unit 10 may consist solely of the resin 17 containing metallic magnetic powder. Examples of resins include epoxy resins, phenolic resins, polyimide resins, acrylic resins, vinyl ether resins, and mixtures thereof. Examples of metallic magnetic powders include powders of metallic magnetic materials such as FeSi alloys (e.g., FeSiCr), FeCo alloys, Fe alloys (e.g., NiFe), or amorphous alloys thereof, or powders of ferrites such as NiZn or MnZn. The content of metallic magnetic powder is preferably 50 vol% to 85 vol% relative to the total resin content. It should be noted that the metallic magnetic powder particles are preferably substantially spherical, and preferably have an average particle size of 5 μm or less.

[0105] The coil 20 is a wiring that extends in a spiral shape along the first main surface 11 and the second main surface 12 of the unit body 10. The coil 20 is preferably a spiral with more than one turn. In this embodiment, the coil 20 has approximately 2.5 turns. For example, viewed from above, the coil 20 is wound in a clockwise spiral shape from the outer peripheral end (second end) towards the inner peripheral end (first end). The coil 20 is made of a conductive material, for example, a low-resistance metal such as Cu, Ag, or Au.

[0106] The first lead wire 51 is preferably formed of the same conductive material as the coil 20, and the coil 20 is electrically connected to the first external terminal 41. The shape of the first lead wire 51 is not particularly limited. In this embodiment, the first lead wire 51 has a portion extending in the X direction and a portion extending in the Y direction. Viewed from above, the first lead wire 51 has a T-shaped shape.

[0107] The first lead-out wiring 51 is electrically connected to the inner peripheral end of the coil 20 via through-hole wiring 61 and through-hole pad 201. Through-hole wiring 61 is the wiring connecting the first lead-out wiring 51 and the coil 20. Through-hole pad 201 is the end of the coil 20 connected to through-hole wiring 61. The first end of the first lead-out wiring 51 is connected to the upper end of through-hole wiring 61. The lower end of through-hole wiring 61 is connected to through-hole pad 201. The second end of the first lead-out wiring 51 is exposed on the first main surface 11 of the unit body 10 and connected to the first external terminal 41. Through this configuration, the coil 20 is electrically connected to the first external terminal 41.

[0108] The second lead-out wiring 52 is preferably formed of the same conductive material as the coil 20, and is a wiring that is electrically connected to the coil 20 and the second external terminal 42. The shape of the second lead-out wiring 52 is not particularly limited. In this embodiment, the second lead-out wiring 52 is a wiring extending in the Y direction. The first end of the second lead-out wiring 52 is connected to the outer peripheral end of the coil 20. The second end of the second lead-out wiring 52 is exposed on the first main surface 11 of the unit body 10 and is connected to the second external terminal 42. With the above configuration, the coil 20 is electrically connected to the second external terminal 42.

[0109] The first external terminal 41 and the second external terminal 42 are formed of conductive materials, such as Cu (low resistance and excellent stress resistance), Ni (excellent corrosion resistance), and Au (excellent solder wettability and reliability), arranged in three layers from the inside to the outside.

[0110] A first external terminal 41 is disposed on the first main surface 11 of the unit body 10, covering the top of the first lead wire 51. Thus, the first external terminal 41 is electrically connected to the inner peripheral end of the coil 20. A second external terminal 42 is disposed on the first main surface 11 of the unit body 10, covering the top of the second lead wire 52 exposed from the first main surface 11. Thus, the second external terminal 42 is electrically connected to the outer peripheral end of the coil 20.

[0111] It is preferable to perform rust prevention treatment on the first external terminal 41 and the second external terminal 42. Here, rust prevention treatment refers to coating with Ni and Au, or Ni and Sn, etc. This can suppress copper leaching and rusting caused by solder, and provide inductor component 1 with high installation reliability.

[0112] (Detailed composition of a unit cell)

[0113] Next, the detailed structure of unit 10 will be explained.

[0114] In unit body 10, at least one of the first to fourth side surfaces 13 to 16, and at least one of the first main surface 11 and the second main surface 12, are provided with one or more recesses. Furthermore, the maximum depth of the deepest recess among the one or more recesses on at least one of the first to fourth side surfaces 13 to 16 is greater than the maximum depth of the deepest recess among the one or more recesses on at least one of the first main surface 11 and the second main surface 12. It should be noted that in this embodiment, one or more recesses are provided on the second side surface 14, and one or more recesses are provided on the first main surface 11.

[0115] Therefore, in this embodiment, the second side 14 corresponds to the "first side" in the scope of the claims, and the first main surface 11 corresponds to the "first main surface".

[0116] Figure 4Afor Figure 3B Enlarged view of region A (second side 14). Figure 4B for Figure 3B An enlarged view of region B (first main face 11). (See attached image.) Figure 4A As shown, a recess 14R is provided on the second side surface 14 of the unit body 10. The shape of the inner surface of the recess 14R is not particularly limited, but it is preferably hemispherical. When the inner surface of the recess 14R is hemispherical, mechanical stress is dispersed on the inner surface of the recess 14R, which can ensure the strength of the unit body 10. Multiple recesses 14R are provided on the second side surface 14, but only one may be provided. The more recesses 14R there are, the higher the heat dissipation is, which is preferred. In addition, if the recesses 14R are evenly distributed, the heat dissipation effect of the second side surface 14 can be obtained over a wider range, which is also preferred. It should be noted that in this embodiment, one or more recesses 14R are provided on the second side surface 14, but the recess may also be provided on any of the first side surface 13, the third side surface 15, and the fourth side surface 16. Alternatively, one or more recesses may be provided on each of the multiple sides 1 to 4 (13 to 16), or one or more recesses may be provided on all sides 1 to 4 (13 to 16). That is, the "first side" in the scope of the claims may be any one of the first side 13, the third side 15, and the fourth side 16.

[0117] In addition, such as Figure 4B As shown, a recess 11R is provided on the first main surface 11 of the unit body 10. The shape of the recess 11R is not particularly limited, but it is preferably hemispherical. Multiple recesses 11R are provided on the first main surface 11, but only one may be provided. In addition, in this embodiment, the recess 11R is provided on the first main surface 11, but the recess may also be provided on the second main surface 12, and one or more recesses may be provided on both the first main surface 11 and the second main surface 12. That is, the "first main surface" in the scope of the claims may also be the second main surface 12.

[0118] The maximum depth of the deepest recess in recess 14R is greater than the maximum depth of the deepest recess in recess 11R. Here, the term "maximum depth of the deepest recess in recess 14R" will be explained. First, in a cross-section containing the center of unit body 10 and orthogonal to the first main surface 11 and the second side surface 14, when multiple recesses 14R exist, D1 is calculated for each. D1 is the maximum value of the depth of the recess 14R in a direction orthogonal to the line segment L1 connecting the first opening end e1 and the second opening end e2 of the recess 14R. Next, the D1 of each of the recesses 14R on the second side surface 14, calculated in this cross-section, is compared, and the maximum value is calculated. This maximum value is the "maximum depth of the deepest recess in recess 14R". It should be noted that when there is only one recess 14R on the second side surface 14 in this cross-section, the D1 of that recess 14R becomes the "maximum depth of the deepest recess in recess 14R".

[0119] Similarly, regarding the "maximum depth of the deepest recess among the recesses 11R", firstly, in the case where there are multiple recesses 11R in a cross-section containing the center of unit body 10 and orthogonal to the first main surface 11 and the second side surface 14, the depth D2 of each recess is calculated. D2 is the maximum value of the depth of the recess 11R in a direction orthogonal to the line segment L2 connecting the first opening end e3 and the second opening end e4 of the recess 11R. Next, the D2 of each of the recesses 11R on the first main surface 11 calculated in this cross-section is compared, and the maximum value among them is calculated. This maximum value is the "maximum depth of the deepest recess among the recesses 11R". It should be noted that when there is only one recess 11R on the first main surface 11 in this cross-section, the D1 of that recess 11R becomes the "maximum depth of the deepest recess among the recesses 11R". The same definition applies to the maximum depth of the recesses in the second main surface 12, the first side surface 13, the third side surface 15, and the fourth side surface 16.

[0120] It should be noted that, in the case of multiple recesses 14R, the maximum depth of all recesses 14R on the second side surface 14 may not be greater than the maximum depth of all recesses 11R on the first main surface 11. That is, there may be recesses 14R with a maximum depth that is smaller than the maximum depth of the recesses 11R on the first main surface 11 among the multiple recesses 14R on the second side surface 14.

[0121] Furthermore, the "recess" in this invention includes a recess that still occurs even after the surface of the unit body 10 is ground flat. For example, the maximum depth in the direction orthogonal to the line segment connecting the first opening end and the second opening end of the recess is 0.5 μm or more.

[0122] Figure 5 A schematic cross-sectional view illustrating the configuration of the region containing the first main face 11 and the second side face 14 of the unit cell. Figure 6This is an image showing the shape of the side surface of a unit cell. Specifically, it is an optical microscope photograph. For example... Figure 5 and Figure 6 As shown, in this embodiment, the unit body 10 is composed of a resin 17 containing metallic magnetic powder. The resin 17 containing metallic magnetic powder has: resin 171, and metallic magnetic powder 172 contained in the resin 171. A recess 14R is provided on the second side surface 14 of the unit body 10. A recess 11R is provided on the first main surface 11 of the unit body 10.

[0123] Here, the first main surface 11 and the second main surface 12 undergo surface grinding in a grinding process. Alternatively, after the grinding process, the first main surface 11 and the second main surface 12 are coated with resin or the like. Therefore, the first main surface 11 and the second main surface 12 have few irregularities and are flat. On the other hand, the first to fourth side surfaces 13 to 16 become monolithically cut surfaces using a dicing blade. In this invention, for example, by controlling the particle size of the dicing blade, the granulation of the metallic magnetic powder 172 in the first to fourth side surfaces 13 to 16 is promoted, and recesses are actively provided on the first to fourth side surfaces 13 to 16, thereby making the maximum depth of the recesses on the side surfaces greater than that on the main surfaces. It should be noted that the recesses of this invention include not only recesses formed by the granulation of the metallic magnetic powder 172, but also recesses formed by other methods.

[0124] According to the inductor component 1 described above, recesses 11R and 14R are provided on at least one of the second side surfaces 14 among the first to fourth side surfaces 13 to 16 of the unit body 10, and on at least one of the first main surfaces 11 among the first main surfaces 11 and the second main surfaces 12. Therefore, the surface area of ​​the unit body 10 is increased, which improves the heat dissipation of the inductor component 1.

[0125] Furthermore, the areas of the first main surface 11 and the second main surface 12 are each larger than the areas of the first to fourth side surfaces 13 to 16. That is, in thin parts where the thickness in the thickness direction is smaller than the width in the length and width directions, the ratio of the maximum depth of the recess on the first main surface 11 and the second main surface 12 to the thickness in the thickness direction is greater than the ratio of the maximum depth of the recess on the first to fourth side surfaces 13 to 16 to the width in the length and width directions. Therefore, the maximum depth of the recess on the first main surface 11 and the second main surface 12 has a greater impact on the impact resistance and bending strength of the part than the maximum depth of the recess on the first to fourth side surfaces 13 to 16. According to the inductor part 1, in thin parts, the maximum depth D1 of the recess 14R in the second side surface 14 is greater than the maximum depth D2 of the recess 11R in the first main surface 11. That is, in thin parts, the maximum depth of the recess 14R on the second side surface 14 is increased compared to the maximum depth of the recess 11R on the first main surface 11. Therefore, the reduction in unit strength caused by the recess can be suppressed, and the surface area of ​​the side surface of the unit 10 can be increased. As a result, heat dissipation can be improved without reducing the strength of the unit 10.

[0126] Furthermore, when mounting inductor component 1, if image recognition of component shape and orientation is required using a surface mount camera, directional identification marks are typically attached to the first main surface 11 or the second main surface 12. When a deep recess is provided on the first main surface 11 or the second main surface 12, it is difficult to distinguish the difference between the recess and the directional identification mark, thus potentially reducing the resolution during image recognition. According to inductor component 1, the maximum depth D1 of the recess 14R in at least one of the second main surface 14 among the first to fourth main surfaces 13 to 16 is greater than the maximum depth D2 of the recess 11R in at least one of the first main surface 11 among the first main surface 11 and the second main surface 12. Therefore, it is easier to distinguish the difference between the recess and the directional identification mark, improving heat dissipation without reducing the resolution during image recognition.

[0127] Preferably, one or more recesses are provided on the second main surface 12, and the maximum depth of the deepest recess in the second side surface 14 is greater than the maximum depth of the deepest recess in the second main surface 12.

[0128] Based on the above configuration, heat dissipation can be improved more effectively without reducing the strength of the unit 10.

[0129] Preferably, one or more recesses are provided on the first side surface 13, the third side surface 15 and the fourth side surface 16 respectively, and the maximum depth of the deepest recess in each of the first side surface 13, the third side surface 15 and the fourth side surface 16 is greater than the maximum depth of the deepest recess in the first main surface 11.

[0130] Based on the above configuration, the heat dissipation of the side surface of the unit 10 can be further improved. Furthermore, since recesses are provided on all sides 13 to 16 (sides 1 to 4), the maximum depth of the recesses can be controlled on each side of each unit, thus controlling the distribution of heat generated from the side surface of the unit. Therefore, after the inductor component 1 is installed, it can be used in conjunction with a cooling fan or similar configuration to flexibly control the heat dissipation of the inductor component 1.

[0131] Preferably, one or more recesses are provided on the first side 13, the third side 15 and the fourth side 16 respectively, and the maximum depth of the deepest recess in each of the first side 13, the third side 15 and the fourth side 16 is greater than the maximum depth of the deepest recess in the first main surface 11 and the maximum depth of the deepest recess in the second main surface 12 respectively.

[0132] Based on the above configuration, the heat dissipation of the side of the unit 10 can be further improved more effectively.

[0133] Preferably, the resin 17 containing metallic magnetic powder is exposed on at least one of the first to fourth sides 13 to 16, and all the recesses on at least one of the first to fourth sides 13 to 16 are provided on the exposed surface of the resin 17 containing metallic magnetic powder.

[0134] The resin 17 containing metallic magnetic powder 172 has high thermal conductivity. According to the above embodiment, all recesses on at least one of the first to fourth sides 13 to 16 are provided on the exposed surface of the resin 17 containing metallic magnetic powder, thus improving the heat dissipation of the inductor component 1 more effectively.

[0135] Preferably, the inner surface of the recess of at least one of the first to fourth sides 13 to 16 is made of resin 171 in resin 17 containing metallic magnetic powder.

[0136] Compared to the portion outside the inner surface of the recess, the inner surface of the recess is more prone to mechanical stress concentration, making it more susceptible to defects such as cracks. According to the above configuration, the inner surface of the recess of at least one of the first to fourth side surfaces 13 to 16 is made of resin 171 from resin 17 containing metallic magnetic powder. Therefore, even when mechanical stress is concentrated on the inner surface of the recess, the generation of defects such as cracks can be suppressed, and the degradation of the characteristics and reliability of the inductor component 1 can be prevented.

[0137] Preferably, the metallic magnetic powder 172 contains iron, and the cut metallic magnetic powder 172 is exposed on at least one of the first to fourth sides 13 to 16. Specifically, for example, as... Figure 5 As indicated by the symbol P, the cut-off metallic magnetic powder 172 is exposed on the second side 14.

[0138] According to the above configuration, the cut-off metallic magnetic powder 172 is exposed on at least one of the first to fourth sides 13 to 16, thereby improving the heat dissipation of the side of the unit body 10.

[0139] Preferably, when the maximum diameter of the exposed surface of the cut metal magnetic powder 172 is set as D (μm) and the distance between the first main surface and the second main surface is set as T (μm), D ≥ 0.3T is satisfied.

[0140] Here, "the maximum diameter of the exposed surface of the cut metal magnetic powder 172" refers to the maximum value among the circular equivalent diameters of the exposed surfaces 172f of the multiple cut metal magnetic powders 172 exposed on at least one of the determined first to fourth side surfaces 13 to 16.

[0141] Based on the above configuration, the maximum diameter of the exposed surface of the metal magnetic powder 172 can be larger, thereby improving the heat dissipation of the side of the unit body 10.

[0142] Ideally, D should be greater than or equal to 10.

[0143] Based on the above configuration, the heat dissipation of the side of the unit 10 can be improved more effectively.

[0144] Preferably, an oxide film is formed on the exposed surface 172f of the cut metal magnetic powder 172.

[0145] The metallic magnetic powder 172 is conductive, and current leakage can occur through it when the cut metallic magnetic powder 172 comes into contact with the external terminal of an adjacent component. According to the above configuration, an oxide film is formed on the exposed surface 172f of the cut metallic magnetic powder 172. The oxide film increases the resistance of the metallic magnetic powder 172, thus improving the short-circuit withstand capability of the inductor component 1. More preferably, the metallic magnetic powder 172 exposed on the first to fourth sides 13 to 16 is not cut, and an oxide film is formed on the exposed surface.

[0146] (Manufacturing method)

[0147] Next, the manufacturing method of inductor component 1 will be described.

[0148] like Figure 7A As shown, a resin 17 containing metallic magnetic powder is prepared as a substrate. At this time, a conductive seed layer (not shown) is formed on the resin 17 containing metallic magnetic powder using a sputtering method or the like. Next, as... Figure 7BAs shown, through-hole pads 201 are formed on a patterned coil 20 and at both ends of the coil 20 using photolithography on a resin 17 containing metallic magnetic powder. The coil 20 and the through-hole pads 201 can be formed as follows: for example, a photoresist patterned using photolithography is disposed on a resin 17 containing metallic magnetic powder and a seed layer; copper is electroplated onto the seed layer within the openings of the photoresist; the photoresist is then removed; and unnecessary portions of the seed layer are removed, thus forming the coil 20. Next, as... Figure 7C As shown, a second layer of resin 17 containing magnetic metal powder is formed on the substrate. Then, the second layer of resin 17 containing magnetic metal powder on the through-hole pad 201 is opened using laser, sandblasting, or the like, and through-hole wiring 61 is formed within the opened hole using electroplating or the like. Next, as... Figure 7D As shown, a first lead wire 51, patterned using photolithography, is provided, with its end connected to the through-hole wire 61 on the inner periphery side of the coil 20. It should be noted that, although not shown, a second lead wire 52 is simultaneously provided on the through-hole wire 61 on the outer periphery side of the coil 20. Then, a third layer of resin 17 containing magnetic metal powder is provided on the first lead wire 51, the second lead wire 52, and the second layer of resin 17 containing magnetic metal powder. Next, holes are created in the third layer of resin 17 containing magnetic metal powder at the ends of the first lead wire 51 and the second lead wire 52 using laser, sandblasting, or the like, and extensions of the first lead wire 51 and the second lead wire 52 extending in the Z direction are provided within these holes. Then, the main surface of the third layer of resin 17 containing magnetic metal powder is planarized by surface grinding or the like. Subsequently, on the first lead wire 51 and the second lead wire 52 exposed from the main surface of the resin 17 containing metallic magnetic powder in the third layer, the first external terminal 41 and the second external terminal 42 are respectively plated or otherwise disposed. Then, they are monolithically formed along tangent C, as shown... Figure 7E As shown, manufacture inductor component 1.

[0149] The recesses on the first to fourth sides 13 to 16 can be formed by the aforementioned single-piece forming process. That is, in the aforementioned single-piece forming process, recesses are formed on the first to fourth sides 13 to 16 by promoting the granulation of the magnetic metal powder. The inventors have conducted various studies, and it has been found that a higher cutting stress applied to each piece of magnetic metal powder promotes granulation. Specifically, for example, adjusting the shearing blade specifications and shearing conditions during single-piece forming with a cutting blade can promote the granulation of the magnetic metal powder.

[0150] The inventors modified the specifications of the shearing blade and observed the state of the cut surface. They discovered that increasing the shearing speed by utilizing the blade increases the cutting resistance due to the moving load of the blade, thereby increasing the stress on the magnetic powder and promoting granulation, thus forming a concave portion on the side of the unit cell. Furthermore, they found that reducing the rotational speed of the shearing blade suppresses blade self-sharpening, thereby increasing the cutting resistance and the stress on the magnetic powder, which also promotes granulation and forms a concave portion on the side of the unit cell. As another method, they discovered that by using a cutting blade with exposed grains on the side, commonly found in electroforming blades, the stress generated when the exposed grains contact the magnetic powder on the side of the unit cell can promote granulation of the magnetic powder.

[0151] It should be noted that the manufacturing method of the inductor component 1 described above is only an example, and the methods and materials used in each process can be replaced with other appropriate known methods and materials. For example, instead of using resin 17 containing metallic magnetic powder as the substrate, a substrate such as ferrite or alumina, and a dry film resist can be used to form the coil 20, through-hole pad 201, through-hole wiring 61, first lead wiring 51, and second lead wiring 52. After removing the substrate and dry film resist, resin 17 containing metallic magnetic powder is pressed from top to bottom to form the unit body 10. Alternatively, instead of the above-described build-up method, a layer-by-layer method or a modeling method can be used.

[0152] (Second Implementation)

[0153] Figure 8 This is a cross-sectional view showing a second embodiment of the inductor component. The unit structure of the second embodiment differs from that of the first embodiment. This difference in structure is explained below. Other components are the same as those in the first embodiment, and the same reference numerals are used, with their descriptions omitted.

[0154] like Figure 8As shown, compared to the inductor component 1 of the first embodiment, the unit body 10 of the inductor component 1A of the second embodiment includes an insulating resin 18 in addition to the resin 17 containing metallic magnetic powder. The insulating resin 18 covers at least the entire surface of the coil 20. The insulating resin 18 is exposed on a portion of the first to fourth side surfaces 13 to 16. Specifically, in the unit body 10, the insulating resin 18 is provided in the area between a plane orthogonal to the Z direction below the coil 20 and a plane orthogonal to the Z direction above the portion extending in the X direction of the first lead wire 51. Thus, the insulating resin 18 exists in the area between each turn of the coil 20. The insulating resin 18 can be, for example, an insulating material mainly composed of epoxy, polyimide, etc., a general printed circuit board or BT resin substrate (i.e., BT resin substrate) impregnated with epoxy resin in glass cloth, FR4 substrate (i.e., glass epoxy substrate), etc. It should be noted that recesses may be provided in the areas where the insulating resin 18 is exposed on the first to fourth sides 13 to 16.

[0155] According to this embodiment, the insulating resin 18 is present in the region between each turn of the coil 20, thereby improving the insulation between the wirings.

[0156] (Third Implementation)

[0157] Figure 9 This is a cross-sectional view showing the third embodiment of the inductor component. The location of the insulating resin differs between the third and second embodiments. This difference is explained below. Other components are the same as in the second embodiment, and the same reference numerals are used; their descriptions are omitted.

[0158] like Figure 9 As shown, in the inductor component 1B of the third embodiment, compared with the inductor component 1A of the second embodiment, the insulating resin 18 is not exposed on the first to fourth sides 13 to 16.

[0159] Specifically, the insulating resin 18 covers at least the entire surface of the coil 20 and is not exposed on the first to fourth sides 13 to 16. Thus, the entire surface of the first to fourth sides 13 to 16 is composed of resin 17 containing metallic magnetic powder.

[0160] According to this embodiment, compared to the second embodiment, the heat dissipation of the inductor components and the insulation between wirings can be improved.

[0161] (Fourth implementation)

[0162] Figure 10This is a cross-sectional view showing the fourth embodiment of the inductor component. The location of the insulating resin in the fourth embodiment differs from that in the second embodiment. This difference is explained below. Other components are the same as in the second embodiment, and the same reference numerals are used; their descriptions are omitted.

[0163] like Figure 10 As shown, compared to the inductor part 1A of the second embodiment, the inductor part 1C of the fourth embodiment has an insulating resin 18 disposed on the first main surface 11. It should be noted that a plurality of recesses 11R are formed on the first main surface 11, but the insulating resin 18 can flatten the unevenness caused by the plurality of recesses 11R, or it can be shaped to reflect the unevenness of the plurality of recesses 11R. Furthermore, the insulating resin 18 can be disposed on the second main surface 12, or on both the first main surface 11 and the second main surface 12.

[0164] According to this embodiment, the heat dissipation of the inductor component 1C can be improved and the insulation between external terminals can be improved.

[0165] It should be noted that the present invention is not limited to the embodiments described above, and the design can be modified within the scope of the present invention. For example, the feature points of the first to fourth embodiments can be combined in various ways.

[0166] In the first embodiment, the coil is a spiral-shaped wiring, but the shape of the coil is not particularly limited. For example, the coil can be spiral, straight, or zigzag. Furthermore, in the first embodiment, the internal wiring is composed of a coil, through-hole pads, through-hole wiring, and lead-out wiring, but the shape and arrangement of the internal wiring are not limited to these. Additionally, the shape and position of the external terminals are not limited.

Claims

1. An inductor part comprising: a unit body, and a coil provided in the unit body; the unit body contains a resin containing a metal magnetic powder, the resin containing a metal magnetic powder having a resin and a metal magnetic powder contained in the resin; the unit body has a shape of a rectangular parallelepiped having a first main surface and a second main surface facing each other, a first side surface, a second side surface, a third side surface, and a fourth side surface connected to the first main surface and the second main surface; each of the first main surface and the second main surface has an area larger than each of the first to fourth side surfaces, one or more recesses are provided on each of the first main surface and the first side surface, a maximum depth of a deepest recess of the one or more recesses of the first side surface is larger than a maximum depth of a deepest recess of the one or more recesses of the first main surface.

2. The inductor part of claim 1, wherein, the first side surface faces the third side surface, the second side surface faces the fourth side surface, a distance between the first main surface and the second main surface is shorter than a distance between the first side surface and the third side surface and a distance between the second side surface and the fourth side surface.

3. The inductor part of claim 1 or 2, wherein, one or more recesses are provided on the second main surface, a maximum depth of a deepest recess of the one or more recesses of the first side surface is larger than a maximum depth of a deepest recess of the one or more recesses of the second main surface.

4. The inductor part of claim 1 or 2, wherein, one or more recesses are provided on each of the second side surface, the third side surface, and the fourth side surface, a maximum depth of a deepest recess of the one or more recesses of each of the second side surface, the third side surface, and the fourth side surface is larger than a maximum depth of a deepest recess of the one or more recesses of the first main surface.

5. The inductor part of claim 1 or 2, wherein, a distance between the first main surface and the second main surface is 300 μm or less.

6. The inductor part of claim 1 or 2, wherein, the resin containing a metal magnetic powder is exposed on the first side surface, all of the recesses of the first side surface are provided on an exposed surface of the resin containing a metal magnetic powder.

7. The inductor part of claim 1 or 2, wherein, an inner surface of at least one of the one or more recesses of the first side surface has a shape of a hemisphere.

8. The inductor part of claim 1 or 2, wherein, the inner surface of at least one of the one or more recesses of the first side surface is composed of the resin in the resin containing a metal magnetic powder.

9. The inductor part of claim 1 or 2, wherein, the metal magnetic powder contains iron, the cut metal magnetic powder is exposed on at least one of the first to fourth side surfaces.

10. The inductor part of claim 9, wherein, when a maximum diameter of an exposed surface of the cut metal magnetic powder is set as D μm and a distance between the first main surface and the second main surface is set as T μm, D ≥ 0.3T is satisfied.

11. The inductor part of claim 10, wherein, D ≥ 10 is further satisfied.

12. The inductor part of claim 9, wherein, an oxidation film is formed on the exposed surface of the cut metal magnetic powder.

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