Inductor and method of manufacturing an inductor

Abstract

Reliability of an inductor is improved. The inductor has a blank (5) having a magnetic molded body (10) and a coil portion (20), a first external electrode formed on a surface of the blank (5), and a second external electrode. The blank (5) has a bottom surface (18), a top surface (19), a first end surface (11) and a second end surface (12), and one side surface (13) and another side surface (14). A first groove (71) is provided on the one side surface (13), the first groove (71) having a depth in a direction from the one side surface (13) toward an inside of the blank (5) and extending in a direction linking the bottom surface (18) and the top surface (19). The coil portion (20) has a winding portion in which a flat wire is wound, and a first lead-out portion which is led out from one end of the winding portion and connected to the first external electrode on the surface of the blank (5). A front end surface (T1e) of the first lead-out portion, which is not covered with an insulating coating, is exposed on a side of the first groove (71) and connected to the first external electrode.

Description

Technical Field

[0001] This disclosure relates to inductors and methods of manufacturing inductors. Background Technology

[0002] Surface mount inductors have traditionally been used where external electrodes are formed on the surface of a chip-shaped blank.

[0003] Patent Document 1 discloses an inductor comprising: a blank having a magnetic body comprising magnetic powder and resin, a coil portion embedded in the magnetic body having a wound wire and a pair of leads extending from the winding portion; and a pair of external electrodes formed on the blank. The magnetic body has a main surface facing each other and multiple side surfaces adjacent to the main surface. A portion of the leads is exposed on one side surface of the magnetic body and connected to the external electrodes. The external electrodes are formed by coating a portion containing one side surface of the magnetic body with a conductive paste. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-167222 Summary of the Invention

[0005] Regarding the inductor described in Patent Document 1, the reliability of the connection between the coil section and the external electrode, which are interconnected via the lead-out section, is sometimes low.

[0006] In view of the above, the purpose of this disclosure is to provide an inductor with higher reliability.

[0007] An inductor according to one aspect of this disclosure comprises: a blank having a magnetic molded body comprising magnetic powder and resin, and a coil portion enclosed within the magnetic molded body; and a first external electrode and a second external electrode formed on the surface of the blank. The blank has: a bottom surface; a top surface opposite to the bottom surface; a first end surface and a second end surface connected to the bottom and top surfaces and opposite to each other; and a side surface and a other side surface connected to the bottom and top surfaces and opposite to each other. A first groove is provided on one side surface, the first groove having a depth in a direction from said side surface toward the interior of the blank, and extending along the direction connecting the bottom and top surfaces. The coil portion is formed of a flat conductor having a metal wire and an insulating coating covering the metal wire, and has: a winding portion formed by winding the flat conductor; a first lead-out portion extending from one end of the winding portion and connected to the first external electrode on the surface of the blank; and a second lead-out portion extending from the other end of the winding portion and connected to the second external electrode on the surface of the blank. The wide surface of the flat conductor of the first lead is arranged along at least a portion of the first end face and at least a portion of one side face, and the front end face not covered by the insulating film is exposed on the side face of the first slot. The first external electrode is connected to the front end face exposed on the side face of the first slot.

[0008] In another aspect of the manufacturing method of an inductor disclosed herein, the inductor comprises: a blank having a magnetic molded body formed of a composite magnetic material comprising magnetic powder and a thermosetting resin, and a coil portion enclosed within the magnetic molded body; and a first external electrode and a second external electrode formed on the surface of the blank. The blank has: a bottom surface; a top surface opposite to the bottom surface; a first end surface and a second end surface connected to the bottom surface and the top surface and opposite to each other; and a side surface and a other side surface connected to the bottom surface and the top surface and opposite to each other. A first groove is provided on one side surface, the first groove having a depth in a direction from the side surface toward the interior of the blank, and extending along a direction connecting the bottom surface and the top surface. The coil portion is formed of a flat conductor having a metal wire and an insulating coating covering the metal wire, and has: a winding portion formed by winding the flat conductor; a first lead-out portion extending from one end of the winding portion and connected to the first external electrode on the surface of the blank; and a second lead-out portion extending from the other end of the winding portion and connected to the second external electrode on the surface of the blank. The manufacturing method of an inductor includes a coil forming process, a preform forming process, a blank forming process, and an external electrode forming process. The coil forming process involves winding a flat conductor parallel to a spool to form a wound portion, a first lead-out portion, and a second lead-out portion. The coil forming process further involves bending the first lead-out portion along at least a portion of a first end face and at least a portion of a side face, with the flat conductor of the first lead-out portion bending along at least a portion of a second end face and at least a portion of a side face, thereby forming the coil portion. The preform forming process involves molding a preform using a composite magnetic material. This preform is part of a blank having a height corresponding to the positional difference between the first and second leads-out portions in the direction connecting the bottom and top surfaces. The blank forming process is as follows: In the cavity of the main forming mold, which has a protrusion corresponding to the first groove, the coil portion, preform, and composite magnetic material are filled in such a manner that the front end face of the first lead, not covered by the insulating film, abuts against the side of the protrusion, and then pressure-formed to form the blank. The external electrode forming process is as follows: A conductive paste is applied to the front end face exposed on the side of the first groove and allowed to cure, thereby forming the first external electrode connected to the front end face.

[0009] According to the inductor and the method for manufacturing the inductor disclosed herein, it is possible to realize an inductor with higher reliability. Attached Figure Description

[0010] Figure 1 This is a perspective view of the inductor in the implementation method. Figure 2 This is a perspective view of the blank of the inductor according to the embodiment. Figure 3 This is a perspective view of the coil section of the inductor according to the embodiment. Figure 4A This is a top view of the coil section of the inductor according to the embodiment. Figure 4B It is a schematic representation Figure 1 A diagram of the cross section at the IVB-IVB line. Figure 5 This is a flowchart illustrating a method for manufacturing an inductor according to an implementation method. Figure 6 This diagram illustrates an example of the coil forming process in the coil forming procedure. Figure 7 This is a perspective view showing an example of an upper preform formed through an upper preform forming process. Figure 8A This is a perspective view showing an example of a lower preform formed through a lower preform forming process. Figure 8B This is a perspective view showing the state in which the coil part is placed on the lower preform. Figure 9A This is a diagram showing the appearance of the main molding die. Figure 9B It is a diagram showing the various blanks after the tumbling grinding process and the metal wire exposure process. Figure 10 This is a perspective view showing another example of a lower preform. Figure 11 This is a perspective view showing another example of a lower preform. Figure 12 This is a perspective view of the inductor blank of a modified embodiment 1. Figure 13 This is a perspective view of the coil portion of the inductor in a modified embodiment 1. Detailed Implementation

[0011] In recent years, with the increasing performance of electronic devices, low power consumption has become a key concern, leading to a demand for low resistance in inductors used as components in electronic devices.

[0012] Conductive pastes generally cure at low temperatures, thus mitigating the thermal impact on the resin and insulating coating of the wires within the magnetic material, and enabling the formation of small external electrodes in a chip-like preform. The conductive paste is formed by dispersing multiple conductive particles, such as silver and copper, in an organic binder resin such as epoxy resin. The external electrode formed from the conductive paste ensures conductivity by utilizing the curing shrinkage during the curing of the organic binder resin to allow the multiple conductive particles to contact other conductive components. On the other hand, when applying the conductive paste, it is necessary to expose at least a portion of the coil portion. For example, if the coil portion is embedded in the magnetic material in a manner that exposes at least a portion of the coil portion, the conductive paste can be applied to that portion, thereby improving the reliability of the connection between the coil portion and the external electrode. In this case, the front end of the coil portion, not covered by the insulating coating, is suitable as the exposed portion. To expose such a front end, it is considered that this front end abuts against the inner surface of the mold cavity of the main molding die used when embedding the coil portion in the magnetic material. Furthermore, by placing the front end of the coil portion against the inner side of the main forming mold, the likelihood of the front end shifting due to the stamping force during the main forming process is reduced. This also provides the advantage of easily maintaining the position of the front end face of the coil portion as constant in the inductor after the magnetic material is formed. In other words, manufacturing the inductor as described above improves the reliability of the connection between the coil portion and the external electrode, and also improves the positioning accuracy of the front end face of the coil portion. Therefore, based on the position of the front end face of the coil portion, it is easier to form other connection points between the coil portion and the external electrode, enabling the realization of an inductor with higher reliability.

[0013] The purpose of this disclosure is to provide an inductor with higher reliability and a method for manufacturing the same, as described above.

[0014] The embodiments are described in detail with reference to the accompanying drawings.

[0015] Furthermore, the embodiments described below are all specific examples of this disclosure. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection methods, steps, and order of steps shown in the following embodiments are examples and are not intended to limit this disclosure. In addition, the constituent elements in the following embodiments that are not described in the independent claims are described as optional constituent elements.

[0016] Furthermore, in this specification, terms such as parallelism indicating the relationship between elements, terms such as cuboid indicating the shape of elements, and numerical ranges are not merely expressions of a strict meaning, but also include expressions of substantially equal ranges, such as differences of a few percent.

[0017] Furthermore, the figures are schematic diagrams that have been appropriately emphasized, omitted, or scaled to illustrate this disclosure, and are not necessarily strictly representational, sometimes differing from actual shapes, positional relationships, and scales. In each figure, structures substantially identical to those in other figures are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified.

[0018] Additionally, the X, Y, and Z axes, representing three mutually orthogonal directions, are shown in the figures. These axes, along with the axial direction along them, are used for illustration as needed. It should be noted that the axes are labeled for illustrative purposes only and do not limit the direction or orientation of the inductor.

[0019] (Implementation Method) [Inductor Structure] Reference Figures 1 to 4B The structure of the inductor in the embodiment will be described. An inductor is a passive element that stores electrical energy flowing through a coil element as magnetic energy.

[0020] Figure 1 This is a perspective view of inductor 1 according to the embodiment. Figure 2 This is a perspective view of the blank 5 of the inductor 1, which includes the coil portion 20 and the magnetic molding body 10. Figure 3 This is a perspective view of the coil section 20 of inductor 1. Figure 4A This is a top view of the coil section 20. Figure 4B It is a schematic representation Figure 1 A diagram of the cross section at the IVB-IVB line.

[0021] exist Figures 1-3 Each of (a) and (b) shows a stereoscopic view viewed from different angles. Figure 2 The diagram shows a blank 5 with the first external electrode 31 and the second external electrode 32 removed from the inductor 1. Additionally, in... Figure 2 In the diagram, the coil section 20 in the blank 5 is represented by a dashed line. Figure 3 Cross-sectional views of the flat conductor w, each with a different cross-section, are shown in (c) and (d). Figure 3 In (c) and (d), the insulating film w2 is shaded, while the shading of the metal wire w1 is omitted. Figure 4B shown Figure 1 The cross section at the IVB-IVB line is included Figure 3 The plane of the axis of the flat conductor w of the first lead-out part 26.

[0022] Figure 1 and Figure 2The inductor 1 shown includes: a blank 5 comprising a magnetically molded body 10 and a coil portion 20 enclosed within the magnetically molded body 10; and a pair of external electrodes formed on the surface of the blank 5. The pair of external electrodes consists of a first external electrode 31 and a second external electrode 32. The inductor 1 of this embodiment is a surface-mount inductor.

[0023] The coil portion 20 is disposed inside the magnetic molded body 10. The coil portion 20 has a winding portion 21 formed by winding a flat wire w and a pair of lead-out portions. The pair of lead-out portions consists of a first lead-out portion 26 and a second lead-out portion 27. The first lead-out portion 26 and the second lead-out portion 27 each have an area where the metal wire w1 of the flat wire w is exposed, i.e., multiple exposed areas (in... Figure 3 (The area enclosed by the dashed line in (a) or (b)). In the inductor 1 of this embodiment, the first external electrode 31 and the second external electrode 32 are respectively connected to a plurality of exposed areas provided in the lead-out portion. According to this structure, the resistance (DC resistance) between the coil portion and the external electrodes can be reduced. Hereinafter, the constituent elements of the inductor 1 will be described.

[0024] The inductor 1 has a general shape determined by, for example, the shape of a cuboid blank 5. The blank 5 can be molded into any shape by a mold. For example, the blank 5 has a length dimension of 2.5 mm in the X-axis direction, a width dimension of 2.0 mm in the Y-axis direction, and a height dimension of 1.1 mm in the Z-axis direction. The blank 5 is composed of a magnetic molding body 10 and a coil portion 20 embedded in the magnetic molding body 10.

[0025] The magnetic molded body 10 is a pressed powder molded body formed from a mixture (composite magnetic material) of magnetic powder as the magnetic material and a binder as the resin material. It should be noted that the magnetic molded body 10 can be formed using any magnetic material. The magnetic material can be ferrite or other magnetic materials. The metallic magnetic powder is a particle-shaped material with a specified elemental composition, such as Fe-Si-Al, Fe-Si, Fe-Si-Cr, or Fe-Si-Cr-B. Furthermore, the binder is a thermosetting resin material such as epoxy resin, selected to insulate the particles of the metallic magnetic powder and maintain a certain shape by bonding the particles of the metallic magnetic powder.

[0026] The magnetic molded body 10 has, for example, a cuboid shape with an outer peripheral surface. The magnetic molded body 10 has a bottom surface 18, a top surface 19, and four surfaces connected to the bottom surface 18 and the top surface 19. These four surfaces are a first end surface 11, a second end surface 12, a side surface 13, and another side surface 14. The bottom surface 18, top surface 19, first end surface 11, second end surface 12, and another side surface 14 are all flat planes. Furthermore, a first groove 71 and a second groove 72 are formed on one side surface 13. Specifically, a first groove 71 and a second groove 72 are provided on one side surface 13, having depth in the direction from that side surface 13 toward the interior of the magnetic molded body 10 and extending along the direction connecting the bottom surface 18 and the top surface 19.

[0027] The first groove 71 is formed closer to the first end face 11 than the second groove 72, such as Figure 1 As shown, after the first external electrode 31 is formed, the first groove 71 is filled with the first external electrode 31 so that its presence is not visible. With this structure, the first external electrode 31 is embedded inside the magnetic molded body 10, making it less likely to detach. That is, the physical connection between the magnetic molded body 10 and the first external electrode 31 is easily maintained, resulting in improved connection reliability between the coil portion 20 and the first external electrode 31. Furthermore, the first groove 71 does not need to be completely filled with the first external electrode 31. The first external electrode 31 only needs to reach the side of the portion of the first groove 71 that participates in the electrical connection between the coil portion 20 and the first external electrode 31. Additionally, the first groove 71 extends to and connects to the bottom surface 18 and the top surface 19. That is, the bottom surface 18 and the top surface 19 have a portion of a flat plane that is recessed corresponding to the first groove 71.

[0028] The second groove 72 is formed closer to the second end face 12 than the first groove 71, such as Figure 1 As shown, after the second external electrode 32 is formed, the second groove 72 is filled with the second external electrode 32 so that its presence is not visible. With this structure, the second external electrode 32 is embedded inside the magnetic molded body 10, making it less likely to detach. That is, the physical connection between the magnetic molded body 10 and the second external electrode 32 is easily maintained, resulting in improved connection reliability between the coil portion 20 and the second external electrode 32. Furthermore, the second groove 72 does not need to be completely filled with the second external electrode 32. The second external electrode 32 only needs to reach the side of the portion of the second groove 72 involved in the electrical connection between the coil portion 20 and the second external electrode 32. Additionally, the second groove 72 extends to and connects to the bottom surface 18 and the top surface 19. That is, the bottom surface 18 and the top surface 19 have a portion of a flat plane that is recessed corresponding to the second groove 72.

[0029] Except for the portion forming the first groove 71 and the second groove 72, the main portion of one side surface 13 has a flat plane. The bottom surface 18 and the top surface 19 are parallel to each other and face away from each other in the Z-axis direction. The first end surface 11 and the second end surface 12 face away from each other in the X-axis direction. One side surface 13 and the other side surface 14 face away from each other in the Y-axis direction.

[0030] The bottom surface 18 and the top surface 19 extend in a direction that intersects with the first end surface 11, the second end surface 12, one side surface 13 and the other side surface 14, specifically in a direction that is orthogonal. In addition, the first end surface 11 and the second end surface 12 extend in a direction that intersects with one side surface 13 and the other side surface 14, specifically in a direction that is orthogonal.

[0031] The first external electrode 31 and the second external electrode 32 are formed on the surface of the blank 5.

[0032] Viewed from a direction perpendicular to the top surface 19, the first external electrode 31 is disposed on the side closer to the first end face 11 than the spool AT of the coil portion 20. Specifically, the first external electrode 31 is formed on the entire surface of the first end face 11 of the blank 5, and is also formed on a portion of each of the bottom surface 18, top surface 19, one side surface 13, and the other side surface 14 in a manner connected to the first external electrode 31 formed on the first end face 11. The first external electrode 31 is, for example, formed to continuously cover each of the bottom surface 18, top surface 19, one side surface 13, and the other side surface 14 from the first end face 11 only in the amount required for filling the first groove 71.

[0033] Viewed from a direction perpendicular to the top surface 19, the second external electrode 32 is disposed further from the second end surface 12 than the spool AT of the coil portion 20. Specifically, the second external electrode 32 is formed on the entire surface of the second end surface 12 of the blank 5, and is also formed on a portion of each of the bottom surface 18, top surface 19, one side surface 13, and the other side surface 14 in a manner connected to the second external electrode 32 formed on the second end surface 12. The second external electrode 32 is, for example, formed to continuously cover each of the bottom surface 18, top surface 19, one side surface 13, and the other side surface 14 from the second end surface 12 only in the amount required for filling the second groove 72.

[0034] like Figure 3 and Figure 4A As shown, the coil portion 20 has a winding portion 21, a first lead-out portion 26, and a second lead-out portion 27. The winding portion 21, the first lead-out portion 26, and the second lead-out portion 27 are formed, for example, by a flat wire w that is a flat wire.

[0035] The flat conductor w consists of a metal wire w1 and an insulating film w2 covering the metal wire w1 (see reference). Figure 3(c) and (d). However, the front end faces of the first lead-out portion 26 side and the second lead-out portion 27 side of the flat conductor w are cut surfaces and are not covered by the insulating film w2. The cross-section of the flat conductor w perpendicular to the axial direction, i.e., the cross-section of the flat conductor w, is rectangular, for example, with a long side of 0.4 mm and a short side of 0.1 mm. The flat conductor w has a wide surface Fw including the long side and a narrow surface including the short side. The metal wire w1 is made of a metal material selected, for example, from metals such as aluminum, copper, silver, and gold, alloys containing one or more of these metals, and materials composed of metals or alloys and other substances. The insulating film w2 is formed of a resin material such as polyimide or polyamide-imide. In this embodiment, the metal wire w1 is formed of copper material, and the insulating film w2 is formed of polyamide-imide. The thickness of the insulating film w2 is, for example, 1 μm or more and 6 μm or less.

[0036] The coil section 20 is composed of a winding section 21, a first lead-out section 26 extending from one end 21a of the winding section 21, and a second lead-out section 27 extending from the other end 21b of the winding section 21.

[0037] The winding section 21 is formed by winding the wide surface Fw of the flat conductor w parallel to the spool AT with the spool AT as the center. The winding section 21 is a rounded rectangular shape and is arranged such that the spool AT intersects with the bottom surface 18 and the top surface 19. Specifically, the winding section 21 is formed by winding the wide surface Fw of the flat conductor w parallel to the spool AT into two layers, upper and lower. In this example, the winding section 21 consists of an upper layer of 4.5 turns, a lower layer of 4.5 turns, and a relay section (not shown) of 0.5 turns that obliquely connects the upper and lower layers at the innermost periphery. A first lead-out portion 26 is connected to one end 21a of the winding section 21, which is the outer periphery of the upper layer, and a second lead-out portion 27 is connected to the other end 21b of the winding section 21, which is the outer periphery of the lower layer.

[0038] The first lead-out portion 26 is led out from one end 21a of the winding portion 21 and connected to the first external electrode 31 on the surface of the blank 5.

[0039] The first lead-out portion 26 has a first end face side lead-out portion 26a disposed along the first end face 11 and a side side lead-out portion 26b disposed along a side surface 13. The first end face side lead-out portion 26a and the side side lead-out portion 26b are disposed substantially parallel to the bottom surface 18. The first end face side lead-out portion 26a is disposed such that it extends from one end 21a of the winding portion 21 along the first end face 11 toward the side surface 13. The side side lead-out portion 26b is bent at a right angle such that it extends toward the second end face 12 with the end of the first end face side lead-out portion 26a as its root, and is disposed along the side surface 13. The side side lead-out portion 26b corresponds to the end of the first lead-out portion 26. For example, the length of the first end face side lead-out portion 26a is less than half the width dimension of the blank 5, and the length of the side side lead-out portion 26b is less than 1 / 3 of the length dimension of the blank 5.

[0040] The wide surface Fw of the flat conductor w of the first lead-out portion 26 extending from the winding portion 21 is arranged along at least a portion of the first end face 11 and at least a portion of a side face 13. The metal wire w1 of the flat conductor w is exposed at the wide surface Fw along the first end face 11 and the side face 13 of the first lead-out portion 26.

[0041] The first lead-out portion 26 has exposed areas T1a and T1b of the metal wire w1 with flat conductor w (see reference). Figure 4B In this example, an exposed area T1a is formed on the wide surface Fw of the first end face side lead-out portion 26a, and an exposed area T1b is formed on the wide surface Fw of one side side lead-out portion 26b. The combined area of ​​the exposed areas T1a and T1b is greater than the cross-sectional area of ​​the metal wire w1. It should be noted that the exposed areas T1a and T1b do not need to be formed on the entire wide surface Fw of the flat conductor w in the first end face side lead-out portion 26a and one side side lead-out portion 26b. For example, the dimension in the height direction (the direction of the long side of the flat conductor w) of each exposed area T1a and T1b can also be shorter than the long side of the flat conductor w.

[0042] The exposed areas T1a and T1b of the first lead-out portion 26 are formed, for example, by removing the insulating coating w2 of the flat wire w using laser processing or sandblasting.

[0043] Specifically, the exposed area T1a is formed by removing both the material of the magnetic molded body 10 located between the first end face side lead-out portion 26a and the first end face 11, and the insulating coating w2 of the flat wire w. Furthermore, when the first end face side lead-out portion 26a and the first end face 11 are disposed on the same surface, the exposed area T1a is formed by removing only the insulating coating w2. This removal process creates a recess in the first end face 11, and the metal wire w1 is exposed on the bottom surface of the recess, which is further inward than the first end face 11. The depth from the first end face 11 to the exposed area T1a (the depth of the recess) is, for example, greater than or equal to the thickness of the insulating coating w2. The exposed area T1a, where the metal wire w1 is exposed, is part of the surface of the blank 5.

[0044] The exposed area T1b is formed by removing both the material of the magnetic molded body 10 located between one side lead-out portion 26b and one side surface 13, and the insulating coating w2 of the flat wire w. Furthermore, when one side lead-out portion 26b and one side surface 13 are disposed on the same surface, the exposed area T1b is formed by removing only the insulating coating w2. This removal process creates a recess in one side surface 13, and the metal wire w1 is exposed on the bottom surface of the recess, which is further inward than one side surface 13. The depth from one side surface 13 to the exposed area T1b (the depth of the recess) is, for example, greater than or equal to the thickness of the insulating coating w2. The exposed area T1b, where the metal wire w1 is exposed, is part of the surface of the blank 5.

[0045] The first lead-out portion 26 is connected to the first external electrode 31 via these exposed areas T1a and T1b. Furthermore, the front end face T1e of the first lead-out portion 26, facing the side of the first groove 71, is not covered by the insulating film w2 and is therefore exposed on the surface of the blank 5. As described above, the first external electrode 31 at least covers this side of the first groove 71, therefore the first lead-out portion 26 is connected to the first external electrode 31 via the front end face T1e.

[0046] Figure 1 The first external electrode 31 shown is formed by coating the surface of the blank 5 with a conductive paste. The conductive paste is a paste material formed by dispersing multiple conductive particles such as silver and copper in an organic binder resin such as epoxy resin. By coating the conductive paste onto the surface of the blank 5, the conductive paste enters the recess and contacts the exposed areas T1a and T1b and the front end face T1e. By curing the conductive paste, the first external electrode 31 is connected to the exposed areas T1a, T1b and the front end face T1e. That is, the first external electrode 31 is connected to the wide surface Fw along the first end face 11 and one side face 13 and the exposed metal wire w1 on the side of the first groove 71, and is connected to the first lead-out portion 26 at the three locations of the first end face 11, one side face 13 and the side of the first groove 71.

[0047] By connecting the first external electrode 31 to the metal wire w1 exposed along the wide surface Fw of the first end face 11 and one side face 13, the first external electrode 31 and the first lead-out portion 26 are connected at multiple locations. Therefore, the contact area between the first external electrode 31 and the first lead-out portion 26 can be increased. This reduces the resistance between the coil portion 20 and the first external electrode 31. Furthermore, by connecting the first external electrode 31 to the metal wire w1 along the first end face 11 and one side face 13, connection areas can be provided in two different directions. This improves the connection strength between the first external electrode 31 and the first lead-out portion 26, and enhances the connection reliability between the coil portion 20 and the first external electrode 31. Moreover, even if poor formation of exposed areas T1a and T1b occurs, the connection reliability between the first external electrode 31 and the coil portion 20 of the inductor 1 is high because the front end face T1e is connected to the first external electrode 31.

[0048] The second lead-out portion 27 and the second external electrode 32 of the inductor 1 in this embodiment also have the same structure as described above.

[0049] The second lead-out portion 27 is led out from the other end 21b of the winding portion 21 and connected to the second external electrode 32 on the surface of the blank 5.

[0050] The second lead-out portion 27 has a second end face side lead-out portion 27a disposed along the second end face 12 and a side side lead-out portion 27b disposed along a side surface 13. The second end face side lead-out portion 27a and the side side lead-out portion 27b are disposed substantially parallel to the bottom surface 18. The second end face side lead-out portion 27a is disposed such that it extends from the other end 21b of the winding portion 21 along the second end face 12 toward the side surface 13. The side side lead-out portion 27b is bent at a right angle with the end of the second end face side lead-out portion 27a as its root and extends toward the first end face 11, and is disposed along the side surface 13. The side side lead-out portion 27b corresponds to the end of the second lead-out portion 27. For example, the length of the second end face side lead-out portion 27a is less than half the width dimension of the blank 5, and the length of the side side lead-out portion 27b is less than 1 / 3 of the length dimension of the blank 5.

[0051] The wide surface Fw of the flat conductor w of the second lead-out portion 27 extending from the winding portion 21 is arranged along at least a portion of the second end face 12 and at least a portion of a side face 13. The metal wire w1 of the flat conductor w is exposed at the wide surface Fw along the second end face 12 and a side face 13 of the second lead-out portion 27.

[0052] The second lead-out portion 27 has exposed areas T2a and T2b of the metal wire w1 of the flat conductor w. In this example, exposed area T2a is formed on the width Fw of the second end face side lead-out portion 27a, and exposed area T2b is formed on the width Fw of one side side lead-out portion 27b. The combined area of ​​exposed areas T2a and T2b is greater than the cross-sectional area of ​​the metal wire w1. It should be noted that exposed areas T2a and T2b do not need to be formed on the entire width Fw of the flat conductor w in the second end face side lead-out portion 27a and one side side lead-out portion 27b. For example, the dimension in the height direction (the direction of the long side of the flat conductor w) of each exposed area T2a and T2b can also be shorter than the long side of the flat conductor w.

[0053] The exposed areas T2a and T2b of the second lead-out section 27 are formed, for example, by removing the insulating coating w2 of the flat wire w using laser processing or sandblasting.

[0054] Specifically, the exposed area T2a is formed by removing both the material of the magnetic molded body 10 located between the second end face side lead-out portion 27a and the second end face 12, and the insulating coating w2 of the flat wire w. Furthermore, when the second end face side lead-out portion 27a and the second end face 12 are disposed on the same surface, the exposed area T2a is formed by removing only the insulating coating w2. This removal process creates a recess in the second end face 12, and the metal wire w1 is exposed on the bottom surface of the recess, which is further inward than the second end face 12. The depth from the second end face 12 to the exposed area T2a (the depth of the recess) is, for example, greater than or equal to the thickness of the insulating coating w2. The exposed area T2a, where the metal wire w1 is exposed, is part of the surface of the blank 5.

[0055] The exposed area T2b is formed by removing both the material of the magnetic molded body 10 located between one side lead-out portion 27b and one side surface 13, and the insulating coating w2 of the flat wire w. Furthermore, when one side lead-out portion 27b and one side surface 13 are disposed on the same surface, the exposed area T2b is formed by removing only the insulating coating w2. This removal process creates a recess in one side surface 13, and the metal wire w1 is exposed on the bottom surface of the recess, which is further inward than one side surface 13. The depth from one side surface 13 to the exposed area T2b (the depth of the recess) is, for example, greater than or equal to the thickness of the insulating coating w2. The exposed area T2b, where the metal wire w1 is exposed, is part of the surface of the blank 5.

[0056] The second lead-out portion 27 is connected to the second external electrode 32 via these exposed areas T2a and T2b. Furthermore, the front end face T2e of the second lead-out portion 27, facing the side of the second groove 72, is not covered by the insulating film w2 and is therefore exposed on the surface of the blank 5. As described above, the second external electrode 32 at least covers this side of the second groove 72, therefore the second lead-out portion 27 is connected to the second external electrode 32 via the front end face T2e.

[0057] The second external electrode 32 is formed by coating the surface of the blank 5 with a conductive paste. The conductive paste is a paste material formed by dispersing multiple conductive particles such as silver and copper in an organic binder resin such as epoxy resin. By coating the conductive paste onto the surface of the blank 5, the conductive paste enters the recess and contacts the exposed areas T2a and T2b and the front end face T2e. By curing the conductive paste, the second external electrode 32 is connected to the exposed areas T2a, T2b and the front end face T2e. That is, the second external electrode 32 is connected to the metal wire w1 exposed along the wide surface Fw of the second end face 12 and one side face 13 and the side face of the second groove 72, and is connected to the second lead-out portion 27 at these three locations: the second end face 12, one side face 13 and the side face of the second groove 72.

[0058] By connecting the second external electrode 32 to the metal wire w1 exposed along the wide surface Fw of the second end face 12 and one side face 13, the second external electrode 32 and the second lead-out portion 27 are connected at multiple locations. Therefore, the contact area between the second external electrode 32 and the second lead-out portion 27 can be increased. This reduces the resistance between the coil portion 20 and the second external electrode 32. Furthermore, by connecting the second external electrode 32 to the metal wire w1 along the second end face 12 and one side face 13, connection areas can be provided in two different directions. This improves the connection strength between the second external electrode 32 and the second lead-out portion 27, and enhances the connection reliability between the coil portion 20 and the second external electrode 32. Moreover, even if poor formation of exposed areas T2a and T2b occurs, the connection reliability between the second external electrode 32 and the coil portion 20 of the inductor 1 is high because the front end face T2e is connected to the second external electrode 32.

[0059] [Inductor Manufacturing Method] The manufacturing method of the inductor 1 according to the embodiment will be described. Here, the manufacturing method of the inductor 1 according to the embodiment will be used as a representative example for description.

[0060] Figure 5 This is a flowchart illustrating the manufacturing method of inductor 1 according to the embodiment.

[0061] like Figure 5As shown, the manufacturing method of inductor 1 includes a coil forming process S110, an upper preform forming process S120, a lower preform forming process S130, a blank forming process S140, a tumbler grinding process S150, a metal wire exposure process S160, and an external electrode forming process S170. Furthermore, the upper preform forming process S120 and the lower preform forming process S130 can also be performed before the coil forming process S110.

[0062] Figure 6 This is a diagram illustrating an example of the formation process of the coil section 20 in the coil section forming process S110.

[0063] In the coil forming process S110, firstly, the wide surface Fw of the flat wire w is wound in a manner parallel to the spool AT to form the winding part 21, the first lead-out part 26, and the second lead-out part 27.

[0064] Specifically, a winding portion 21 is formed by winding the wide surface Fw of a flat conductor w in a manner parallel to the spool AT into two layers, and a first lead-out portion 26 extending from the upper layer side of the winding portion 21 and a second lead-out portion 27 extending from the lower layer side of the winding portion 21 are formed (see reference). Figure 6 ).

[0065] Then, in the subsequent blank forming process S140, the first lead-out portion 26 is pre-bent so that the wide surface Fw of the flat conductor w of the first lead-out portion 26 is arranged along at least a portion of the first end face 11 and at least a portion of one side face 13. Additionally, in the blank forming process S140, the second lead-out portion 27 is pre-bent so that the wide surface Fw of the flat conductor w of the second lead-out portion 27 is arranged along at least a portion of the second end face 12 and at least a portion of one side face 13 (see reference). Figure 3 Through these bending processes, the end of the first lead-out portion 26 (one side lead-out portion 26b) and the end of the second lead-out portion 27 (one side lead-out portion 27b) are formed.

[0066] In the upper preform formation process S120, a composite magnetic material, which is a mixture of magnetic powder and binder, is preformed using an upper preform mold to obtain an upper preform 50 with a plate shape.

[0067] Figure 7 This is a perspective view showing an example of an upper preform 50 formed by the upper preform forming process S120.

[0068] The upper preform 50 has a cuboid shape with an outer diameter smaller than the cavity of the main mold. The upper preform 50 is formed, for example, by pressure molding at room temperature.

[0069] In the lower preform forming process S130, the composite magnetic material is preformed using a lower preform mold to obtain the lower preform 60.

[0070] Figure 8A This is a perspective view showing an example of a lower preform 60 formed by the lower preform forming process S130. Figure 8A This indicates the state before the coil part 20 is placed on the lower preform 60.

[0071] Figure 8B This is a perspective view showing the state in which the coil portion 20 is mounted on the lower preform 60. Furthermore, in Figure 8B The arrangement of the lower preform 60 and the coil part 20 in the blank forming process S140 is shown.

[0072] The lower preform 60 includes: a base plate 61 in the shape of a plate; a frame portion 63 disposed on the base plate 61; and a columnar portion 64. The lower preform 60 is formed, for example, by heating and pressurizing at a temperature higher than room temperature. The formed lower preform 60 can be in a semi-cured state or a fully cured state.

[0073] The base plate 61 has a cuboid shape with an outer diameter smaller than the cavity of the main forming mold. That is, when viewed from the pressure forming direction, the base plate 61 has a rectangular shape. Hereinafter, the shape of the lower preform 60 will sometimes be described based on the outer shape of the blank 5 formed in subsequent processes. A first recess 71a corresponding to the first groove 71 is formed in the base plate 61. In addition, a second recess 72a corresponding to the second groove 72 is formed in the base plate 61.

[0074] The support portion 63 is erected on the outer periphery of one of the two long sides of the base plate 61. The support portion 63 is formed between the first recess 71a and one short side of the base plate 61. The short side of the base plate 61 refers to the side that becomes the first end face 11 of the blank 5 in the blank forming process S140. The height of the support portion 63 is the same as the long side of the flat guide wire w.

[0075] The frame portion 63 is pre-formed in such a way that it is positioned below the end of the first lead-out portion 26, which is drawn out from the upper side of the winding portion 21, before the pressure forming process S140 of the blank forming process.

[0076] The columnar portion 64 is erected at two corners on the outer periphery of the other long side of the base plate 61. The other long side refers to the side that forms the other side 14 of the blank 5 in the blank forming process S140. The columnar portion 64 is formed such that the surface of the central side of the base plate 61 is concave. The columnar portion 64 is pre-formed such that it is arranged along the outer periphery of the winding portion 21 before the pressure forming in the blank forming process S140.

[0077] In the blank forming process S140, the blank 5 is formed by filling the cavity of the main forming mold with the coil part 20 and the composite magnetic material and then pressing it. The composite magnetic material refers to the lower preform 60 and the upper preform 50 mentioned above.

[0078] Figure 9A This diagram shows the appearance of the main forming mold. The main forming mold consists of an upper stamping die 91, a cylindrical die 92 with a mold cavity, and a lower stamping die 93. The upper stamping die 91 and the lower stamping die 93 have punches with the same shape as the mold cavity. The upper stamping die 91 defines the top surface 19, and the lower stamping die 93 defines the bottom surface 18. Furthermore, the cylindrical die 92 defines a first end face 11, a second end face 12, a side face 13, and a side face 14. Two protrusions 92a are formed in the mold cavity of the cylindrical die 92, corresponding to the first groove 71 and the second groove 72, respectively. It should be noted that this example illustrates the use of the cylindrical die 92 as the main forming mold. In a mold cavity such as cylindrical mold 92, since blanks with the same cross-sectional shape in the cylindrical axis direction are required, the first groove 71 and the second groove 72 are connected to the bottom surface 18 and the top surface 19. However, if a parting mold that can divide a part of the mold cavity is used as the main forming mold, for example, the first groove 71 and the second groove 72 can also be made not connected to the bottom surface 18 and the top surface 19.

[0079] In the blank forming process S140, firstly, the lower preform 60 is placed into the mold cavity of the cylindrical mold 92 along the two protrusions 92a, with the first recess 71a and the second recess 72a in contact with the first protrusion 71a and the second protrusion 72a. Then, the coil portion 20 is placed on the lower preform 60 such that the front end face T1e of the first lead-out portion 26 abuts against one side of the two protrusions 92a, and the front end face T2e of the second lead-out portion 27 abuts against the other side of the two protrusions 92a. More precisely, "abutting" here means that a small gap is provided to allow it to be filled into the mold cavity.

[0080] Before pressure molding, the coil portion 20 is arranged such that the end of the first lead-out portion 26 is located above the frame portion 63, and the winding portion 21 and the second lead-out portion 27 are arranged on the base plate 61. The winding portion 21 is arranged closer to the center of the base plate 61 than the columnar portion 64.

[0081] Viewed from the lower preform 60, in other words, the frame portion 63 is positioned below the end of the first lead-out portion 26 extending from the upper side of the winding portion 21. The base plate 61 is positioned below the winding portion 21 and the second lead-out portion 27. The concave curved surface of the columnar portion 64 is positioned along the outer periphery of the winding portion 21.

[0082] In the blank forming process S140, after the upper preform 50 is placed on the coil portion 20, pressure forming is performed. This forms a blank 5 containing the coil portion 20 and an inner coil portion 20 magnetic molded body 10. At this time, the upper stamping die 91 and the lower stamping die 93 are stamped in the direction along the spool AT of the coil portion 20, and the entire blank 5 is expanded in the direction intersecting the spool AT. The coil portion 20 is also expanded, but the amount of expansion of the coil portion 20 is limited because the front end faces T1e and T2e abut against the protrusion 92a. That is, the front end faces T1e and T2e are pressed against the side of the protrusion 92a, thus preventing the coil portion 20 from expanding beyond the necessary extent. As a result, the positions of the front faces T1e and T2e are difficult to move due to the side of the pressed protrusion 92a, and consequently, the positions of the first lead-out portion 26 and the second lead-out portion 27 having the front faces T1e and T2e are also easily restricted. That is, the positioning accuracy of the first lead-out portion 26 and the second lead-out portion 27 is improved. If the positioning accuracy of the first lead-out portion 26 and the second lead-out portion 27 is improved, the forming accuracy of the exposed areas T2a and T2b is also improved, thus enabling an inductor 1 with higher connection reliability.

[0083] In the next step, the blank 5 is removed from the cavity of the main forming mold, and then the blank 5 is subjected to heat treatment or other treatments to substantially completely cure the semi-cured or uncured areas of the binder in the composite magnetic material. At this time, the temperature conditions for treatment are selected to be optimal according to the type of magnetic material used.

[0084] Figure 9B This diagram shows the individual blanks 5 after the tumbling grinding process S150 and the metal wire exposure process S160. Figure 9B (a) shows the blank 5 after performing the tumbling grinding process S150, and (b) shows the blank 5 after performing the metal wire exposure process S160.

[0085] In the tumbling grinding process S150, the burrs formed on the blank 5 in the blank forming process S140 are removed by placing the blank 5 into a drum-shaped container and tumbling it. Additionally, tumbling grinding removes the corners of the blank 5, forming R-shaped rounded corners at the corners of the blank 5. (See also...) Figure 12The first angular surface r1, the other first angular surface r1, the second angular surface r2, and the other second angular surface r2, described later, are formed on the blank 5 by a tumbling grinding process S150. Alternatively, a process of coating the blank 5 with resin may be provided after the tumbling grinding process S150.

[0086] In the metal wire exposure process S160, exposed areas T1a, T1b, T2a, and T2b are formed by removing the insulating film w2 of the flat conductor w formed on the first lead-out portion 26 and the second lead-out portion 27. The exposed areas T1a, T1b, T2a, and T2b are formed by irradiating the insulating film w2, which is made of polyamide-imide resin, with a green laser or a UV laser to remove the insulating film w2. As a result, the metal wire w1 is exposed along the width Fw of the flat conductor w along the first end face 11 and one side face 13 in the first lead-out portion 26. Similarly, the metal wire w1 is exposed along the width Fw of the flat conductor w along the second end face 12 and one side face 13 in the second lead-out portion 27.

[0087] In the external electrode forming process S170, a conductive paste is applied to the surface of the blank 5. More specifically, by applying the conductive paste to the surface of the blank 5, the conductive paste is applied to the metal wire w1 exposed along the wide surface Fw of the first end face 11 and one side face 13 and the side of the first groove 71. Then, the conductive paste is cured to form a first external electrode 31 connected to the metal wire w1. Additionally, by applying the conductive paste to the surface of the blank 5, the conductive paste is applied to the metal wire w1 exposed along the wide surface Fw of the second end face 12 and one side face 13 and the side of the second groove 72. Then, the conductive paste is cured to form a second external electrode 32 connected to the metal wire w1. Furthermore, the external electrode forming process S170 may also include a process of plating the external electrode formed by applying and curing the conductive paste with Ni or Sn.

[0088] Inductor 1 is manufactured by performing these processes S110 to S170.

[0089] In addition, Figure 8A An example of the lower preform 60 is shown, but the shape of the lower preform 60 is not limited to this.

[0090] Figure 10 and Figure 11 This is a perspective view showing another example of the lower preform 60.

[0091] like Figure 10As shown, a wall portion 66 may also be provided on the lower preform 60. The wall portion 66 is vertically provided on a portion of the outer periphery of the base plate 61. The wall portion 66 is formed on the outer periphery of one of the two long sides of the base plate 61. One long side refers to the side that becomes one side 13 of the blank 5 in the blank forming process S140. The length of the wall portion 66 in the long side direction of the base plate 61 is shorter than the length dimension of the blank 5. The wall portion 66 is pre-formed on the side 13 of the blank 5 formed in the blank forming process S140, located between the end of the first lead-out portion 26 and the end of the second lead-out portion 27.

[0092] The height of the wall portion 66 is equal to the long side (long side of the cross-section) of the flat conductor w. Furthermore, the wall portion 66 is flat. Alternatively, the wall portion 66 can be formed with a concave curved surface on the central side of the base plate 61. In this case, the wall portion 66 can be pre-formed such that the concave curved surface is arranged along the outer periphery of the winding portion 21 before the pressure forming process S140.

[0093] like Figure 11 As shown, the base plate 61 can also have a simpler shape. In this example, a portion of the base plate 61 (the dotted line portion in the figure) used to define the first recess 71a and the second recess 72a is cut, so it is not necessary to place the lower preform 60 into the mold cavity of the cylindrical mold 92 along the two protrusions 92a with the first recess 71a and the second recess 72a in this manner. That is, the process of placing the lower preform 60 into the mold cavity can be simplified. In this case, a composite magnetic material with high fluidity can be selected to compensate for the portion of the composite magnetic material that is cut during pressing. In addition, recesses corresponding to the first groove 71 and the second groove 72 can be provided on the upper preform 50, or any other lower preform 60 and upper preform 50 can be used.

[0094] [Modification 1 of the implementation method] The inductor 1A of the modified example 1 of the embodiment will be described. In the modified example 1, an example in which the external electrode is connected to the metal wire w1 exposed at the corner of the blank 5A will be described.

[0095] The inductor 1A of Modified Example 1 includes: a blank 5A comprising a magnetic molded body 10 and a coil portion 20 enclosed within the magnetic molded body 10; and a first external electrode 31 and a second external electrode 32 formed on the surface of the blank 5A. The appearance of the inductor 1A is as follows: Figure 1 As shown.

[0096] Figure 12 This is a perspective view of the blank 5A of the inductor 1A in the modified example 1 of the embodiment. Figure 13 This is a 3D view of the coil section 20A of inductor 1A.

[0097] The inductor 1A of Modified Example 1 is based on the inductor 1 of Embodiment 1, and also has the structure shown below.

[0098] The blank 5A of Modified Example 1 has a first angular curved surface r1 connected to a first end face 11 and a side face 13. The wide surface Fw of the flat conductor w of the first lead-out portion 26A is arranged along the first angular curved surface r1, and the metal wire w1 is exposed on the wide surface Fw along the first angular curved surface r1. The first external electrode 31 is connected to the metal wire w1 exposed on the wide surface Fw along the first angular curved surface.

[0099] Furthermore, the blank 5A of Modified Example 1 has a second curved surface r2 connected to the second end face 12 and a side face 13. The wide surface Fw of the flat conductor w of the second lead-out portion 27A is arranged along the second curved surface r2, and the metal wire w1 is exposed along the wide surface Fw of the second curved surface r2. The second external electrode 32 is connected to the metal wire w1 exposed along the wide surface Fw of the second curved surface r2.

[0100] By connecting the first external electrode 31 to the metal wire w1 exposed along the wide surface Fw of a first curved surface r1, the contact area between the first external electrode 31 and the first lead-out portion 26A can be further increased. This reduces the resistance between the coil portion 20A and the first external electrode 31. Furthermore, by connecting the second external electrode 32 to the metal wire w1 exposed along the wide surface Fw of a second curved surface r2, the contact area between the second external electrode 32 and the second lead-out portion 27A can be further increased. This reduces the resistance between the coil portion 20A and the second external electrode 32.

[0101] Furthermore, when the distance between the first curved surface r1 and the first lead-out portion 26A is greater than a predetermined value (e.g., greater than the short side dimension of the flat wire w), the indentation of the first external electrode 31 relative to the blank 5A increases, thereby increasing the peel strength of the first external electrode 31 relative to the blank 5A. Similarly, when the distance between the second curved surface r2 and the second lead-out portion 27A is greater than a predetermined value (e.g., greater than the short side dimension of the flat wire w), the indentation of the second external electrode 32 relative to the blank 5A increases, thereby increasing the peel strength of the second external electrode 32 relative to the blank 5A.

[0102] Furthermore, the inductor 1A of Modified Example 1 is manufactured using the same manufacturing method as the inductor 1 of the embodiment. When the metal wire w1 is exposed to one of the first angular curved surface r1 and the second angular curved surface r2, the following method can be employed. First, in the coil forming process, the coil portion 20A is pre-formed such that the wide surface Fw of the first lead 26A is positioned along a first angular curved surface r1 connecting the first end face 11 and a side face 13 of the blank 5A to be formed in the blank forming process, and the wide surface Fw of the second lead 27A is positioned along a second angular curved surface r2 connecting the second end face 12 and a side face 13 of the blank 5A. Then, in the metal wire exposure process, the metal wire w1 is exposed along the wide surface Fw of the first angular curved surface r1 and along the wide surface Fw of the second angular curved surface r2.

[0103] (Summarize) The following examples illustrate the structures of inductors and the like in the embodiments.

[0104] [Example 1] The inductor 1 of this embodiment includes: a blank 5 having a magnetic molded body 10 comprising magnetic powder and resin, and a coil portion 20 enclosed within the magnetic molded body 10; and a first external electrode 31 and a second external electrode 32 formed on the surface of the blank 5. The blank 5 has a bottom surface 18, a top surface 19 opposite to the bottom surface 18, a first end surface 11 and a second end surface 12 connected to the bottom surface 18 and the top surface 19 and opposite to each other, a side surface 13 connected to the bottom surface 18 and the top surface 19 and opposite to each other, and another side surface 14. A first groove 71 is provided on one side surface 13, the first groove 71 having a depth in the direction from the side surface 13 toward the interior of the blank 5, and extending along the direction connecting the bottom surface 18 and the top surface 19. The coil portion 20 is formed of a flat conductor having a metal wire w1 and an insulating film w2 covering the metal wire w1, and has: a winding portion 21 formed by winding the flat conductor; a first lead-out portion 26 extending from one end of the winding portion 21 and connected to a first external electrode 31 on the surface of the blank 5; and a second lead-out portion 27 extending from the other end of the winding portion 21 and connected to a second external electrode 32 on the surface of the blank 5. The wide surface of the flat conductor of the first lead-out portion 26 is arranged along at least a portion of the first end face 11 and at least a portion of one side face 13, and the front end face T1e not covered by the insulating film w2 is exposed on the side of the first groove 71. The first external electrode 31 is connected to the front end face T1e exposed on the side of the first groove 71.

[0105] By performing this operation, the first external electrode 31 enters the interior of the magnetic molded body 10 at the first groove 71, thus reducing the possibility of the first external electrode 31 detaching from the magnetic molded body 10. Furthermore, by forming an electrical connection between the first external electrode 31 and the coil portion 20 via the exposed front end surface T1e on the side of the first groove 71, an inductor 1 with higher reliability from the viewpoint of connection stability can be achieved. Additionally, when forming other connection points between the coil portion 20 and the first external electrode 31, positioning can be based on the position of the front end surface T1e, thus ensuring proper connection positioning and providing the advantage of easily achieving a more reliable inductor 1.

[0106] [Example 2] In the inductor 1 of Example 1, the first lead 26 further exposes a metal wire w1 on a wide surface along the first end face 11 and a side face 13, and the first external electrode 31 is further connected to the metal wire w1 exposed on the wide surface along the first end face 11 and a side face 13.

[0107] By performing this operation, an electrical connection between the first external electrode 31 and the coil portion 20 can also be formed on the first end face 11 and one side face 13. Moreover, when forming other connection points between the coil portion 20 and the first external electrode 31, positioning can be based on the position of the front end face T1e, thus ensuring proper connection positions and making it easier to achieve a more reliable inductor 1.

[0108] [Example 3] In the inductor 1 of Example 1 or Example 2, the length of the portion of the first lead 26 disposed along at least a portion of a side surface 13 is shorter than the length of the portion disposed along at least a portion of the first end face 11.

[0109] In this way, an inductor 1 can be realized having a first lead-out portion 26 whose length along at least a portion of one side surface 13 is shorter than the length along at least a portion of the first end surface 11. When manufacturing the inductor 1, if the blank 5 is formed by applying pressure in the direction of applying a force to unwind the winding portion 21 of the coil portion 20, the force of unwinding the winding portion 21 can be used as a force to expose the front end face T1e on the side of the first groove 71. For example, in the main forming mold, if a mold cavity is provided with a protrusion 92a corresponding to the first groove 71, the front end face T1e can be pressed against the protrusion 92a, thus making it easy for the front end face T1e to be exposed.

[0110] [Example 4] In the inductor 1 of any of Examples 1 to 3, the first slot 71 extends to the bottom surface 18 and the top surface 19.

[0111] By operating in this way, an inductor 1 with a first slot 71 extending to the bottom surface 18 and the top surface 19 can be realized.

[0112] [Example 5] In the inductor 1 of any of Examples 1 to 4, on one side 13, a second groove 72 is provided closer to the second end face 12 than the first groove 71. The second groove 72 has depth in the direction from the side 13 toward the interior of the blank 5 and extends along the direction connecting the bottom surface 18 and the top surface 19. The wide surface of the flat conductor of the second lead 27 is arranged along at least a portion of the second end face 12 and at least a portion of the side 13, and the front end face T2e, which is not covered by the insulating film w2, is exposed on the side of the second groove 72. The second external electrode 32 is connected to the front end face T2e exposed on the side of the second groove 72.

[0113] By operating in this way, the same effect as the first groove 71 can be achieved near the second end face 12. Specifically, the second external electrode 32 enters the interior of the magnetic molded body 10 at the second groove 72, thus reducing the possibility of the second external electrode 32 detaching from the magnetic molded body 10. In addition, the electrical connection between the second external electrode 32 and the coil portion 20 is formed via the front end face T2e exposed on the side of the second groove 72, enabling an inductor 1 with higher reliability from the viewpoint of connection stability. Furthermore, when forming other connection points between the coil portion 20 and the second external electrode 32, positioning can be based on the position of the front end face T2e, thus ensuring proper connection positioning, and therefore also providing the advantage of easily achieving an inductor 1 with higher reliability.

[0114] [Example 6] In the manufacturing method of the inductor 1 according to this embodiment, the inductor 1 includes: a blank 5 having a magnetic molded body 10 formed of a composite magnetic material including magnetic powder and thermosetting resin, and a coil portion 20 enclosed in the magnetic molded body 10; and a first external electrode 31 and a second external electrode 32 formed on the surface of the blank 5. The blank 5 has: a bottom surface 18; a top surface 19 opposite to the bottom surface 18; a first end surface 11 and a second end surface 12 connected to the bottom surface 18 and the top surface 19 and opposite to each other; and a side surface 13 connected to the bottom surface 18 and the top surface 19 and opposite to each other and another side surface 14. A first groove 71 is provided on one side surface 13, the first groove 71 having a depth in the direction from the side surface 13 toward the interior of the blank 5, and extending along the direction connecting the bottom surface 18 and the top surface 19. The coil portion 20 is formed of a flat conductor having a metal wire w1 and an insulating film w2 covering the metal wire w1, and includes: a winding portion 21 formed by winding the flat conductor; a first lead-out portion 26, which extends from one end of the winding portion 21 and is connected to a first external electrode 31 on the surface of the blank 5; and a second lead-out portion 27, which extends from the other end of the winding portion 21 and is connected to a second external electrode 32 on the surface of the blank 5. The manufacturing method of the inductor 1 includes a coil portion forming step S110, a preform forming step, a blank forming step S140, and an external electrode forming step S170. The coil portion forming step S110 involves winding the wide surface of the flat conductor in a manner parallel to the spool AT to form the winding portion 21, the first lead-out portion 26, and the second lead-out portion 27. The coil forming process S110 is as follows: the first lead 26 is bent along at least a portion of the first end face 11 and at least a portion of one side face 13 with the wide surface of the flat wire of the first lead 26, and the second lead 27 is bent along at least a portion of the second end face 12 and at least a portion of one side face 13 with the wide surface of the flat wire of the second lead 27, thereby forming the coil 20. The preform forming process (upper preform forming process S120 and lower preform forming process S130) is as follows: a preform is formed using a composite magnetic material. This preform is a part of the blank 5 of the frame 63 having a height corresponding to the difference in position between the first lead 26 and the second lead 27 in the direction connecting the bottom surface 18 and the top surface 19. The blank forming process S140 is as follows: In the mold cavity of the main forming mold having a protrusion 92a corresponding to the first groove 71, the coil part 20, the preform and the composite magnetic material are filled in such a way that the front end face T1e of the first lead-out part 26, which is not covered by the insulating film w2, abuts against the side of the protrusion 92a, and then pressure forming is performed to form the blank 5.The external electrode forming process S170 is as follows: by applying a conductive paste to the exposed front end surface T1e on the side of the first groove 71 and curing it, a first external electrode 31 connected to the front end surface T1e is formed.

[0115] The inductor 1 described above can be provided by the manufacturing method described above.

[0116] (Other implementation methods, etc.) The inductors and other components of the embodiments and modifications of this disclosure have been described above, but this disclosure is not limited to the above-described embodiments and modifications. Various modifications conceived by those skilled in the art to the embodiments and modifications, as well as other methods of constructing embodiments and modifications by combining some of the constituent elements of the embodiments and modifications, are also included within the scope of this disclosure, provided they do not depart from the spirit of the disclosure.

[0117] For example, electrical products or circuits using the aforementioned inductor are also included in this disclosure. Examples of electrical products include power supply devices equipped with the aforementioned inductor and various devices equipped with such power supply devices. Industrial applicability

[0118] The inductor disclosed herein is useful as an inductor for various devices and equipment, etc. Explanation of reference numerals in the attached figures

[0119] 1. 1A Inductor 5. 5A billet 10 Magnetic Molded Body 11 First end face 12 Second end face 13 One side 14. Another aspect 18 Bottom 19 Top surface 20, 20A Coil Section 21. Winding section 21a One end 21b The other end 26, 26A First Lead-Out Section 26a First end face side lead-out portion 26b Side lead-out section 27, 27A Second lead-out section 27a Second end face side lead-out portion 27b Side lead-out section 31 First external electrode 32 Second external electrode 50 Upper preform 60 Lower preform 61 Base Plate 63 units 64. Columnar portion 66 Wall section 71 First trench 71a first recess 72 Second slot 72a Second recess 91 Upper stamping die 92 cylindrical mold 92a protrusion 93 Lower stamping die AT reel w flat wire w1 metal wire w2 Insulation film Fw wide format r1 First Angle Surface r2 Second Angle Surface Exposed areas of T1a, T1b, T2a, and T2b T1e and T2e front faces.

Claims

1. An inductor comprising: a blank having a magnetic molded body comprising magnetic powder and resin, and a coil portion enclosed within the magnetic molded body; and a first external electrode and a second external electrode formed on the surface of the blank, wherein, The blank body comprises: a bottom surface; a top surface opposite to the bottom surface; a first end surface and a second end surface connected to the bottom surface and the top surface and opposite to each other; and a side surface and a other side surface connected to the bottom surface and the top surface and opposite to each other. A first groove is provided on one side, the first groove having a depth in the direction from the one side toward the interior of the blank, and extending along the direction connecting the bottom surface and the top surface. The coil portion is formed of a flat conductor having a metal wire and an insulating film covering the metal wire, and has: a winding portion formed by winding the flat conductor; and a first lead-out portion that leads out from one end of the winding portion and is connected to the first external electrode on the surface of the blank. The second lead-out portion extends from the other end of the winding portion and connects to the second external electrode on the surface of the blank. The wide surface of the flat conductor of the first lead-out portion is arranged along at least a portion of the first end face and at least a portion of one side face, and the front end face not covered by the insulating film is exposed on the side of the first groove. The first external electrode is connected to the front end face exposed on the side of the first groove.

2. The inductor according to claim 1, wherein, The first lead-out portion further exposes the metal wire along the wide surface of the first end face and the side face. The first external electrode is further connected to the metal wire exposed along the wide surface of the first end face and the side face.

3. The inductor according to claim 1, wherein, The length of the portion of the first lead-out that is configured along at least a portion of one side is shorter than the length of the portion configured along at least a portion of the first end face.

4. The inductor according to claim 1, wherein, The first groove extends to the bottom surface and the top surface.

5. The inductor according to any one of claims 1 to 4, wherein, On one side, a second groove is positioned closer to the second end face than the first groove. The second groove has depth on the side facing the interior of the blank and extends along the direction connecting the bottom surface and the top surface. The wide surface of the flat conductor of the second lead-out portion is arranged along at least a portion of the second end face and at least a portion of one side face, and the front end face not covered by the insulating film is exposed on the side of the second groove. The second external electrode is connected to the front end face exposed on the side of the second groove.

6. A method for manufacturing an inductor, the inductor comprising: a blank having a magnetic molded body formed of a composite magnetic material comprising magnetic powder and a thermosetting resin, and a coil portion enclosed within the magnetic molded body; and a first external electrode and a second external electrode formed on the surface of the blank. The blank has: a bottom surface; a top surface opposite to the bottom surface; a first end surface and a second end surface connected to the bottom surface and the top surface and opposite to each other; and a side surface and another side surface connected to the bottom surface and the top surface and opposite to each other. A first groove is provided on one side, the first groove having a depth in the direction from the one side toward the interior of the blank, and extending along the direction connecting the bottom surface and the top surface. The coil portion is formed of a flat conductor having a metal wire and an insulating film covering the metal wire, and has a winding portion formed by winding the flat conductor. The first lead-out portion extends from one end of the winding portion and is connected to the first external electrode on the surface of the blank; And a second lead-out portion, which extends from the other end of the winding portion and connects to the second external electrode on the surface of the blank. The method for manufacturing the inductor includes: The coil forming process involves winding the flat conductor parallel to the spool to form the winding portion, the first lead-out portion, and the second lead-out portion. Then, the first lead-out portion is bent along at least a portion of the first end face and at least a portion of one side face, and the second lead-out portion is bent along at least a portion of the second end face and at least a portion of one side face, thereby forming the coil portion. The preform forming process uses the composite magnetic material to form a preform, which is a part of the blank having a frame portion having a height corresponding to the difference in position between the first lead-out portion and the second lead-out portion in the direction connecting the bottom surface and the top surface; The blank forming process involves filling the coil portion, the preform, and the composite magnetic material into a mold cavity of a main forming mold having protrusions corresponding to the first groove, such that the front end face of the first lead-out portion not covered by the insulating film abuts against the side of the protrusions, and then pressing and forming the blank; and The external electrode forming process involves applying a conductive paste to the exposed front end face on the side of the first groove and allowing it to cure, thereby forming the first external electrode connected to the front end face.

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