JP7507337B2 - Inductor and manufacturing method thereof - Google Patents

Description

This disclosure relates to an inductor and a method for manufacturing the same.

Conventionally, inductors have been introduced into a wide range of electronic devices, such as DC-DC converter devices, for the purpose of stepping up and down the power supply voltage and smoothing the direct current. In recent years, high-frequency drive DC-DC converter devices, in which the switching frequency in the drive circuit of the DC-DC converter device is increased, have also become known. In addition, inductors that exhibit low inductance values have been developed in conjunction with the increase in switching frequency. As a specific inductor structure, for example, a magnetic element having a flat plate-shaped current-carrying member has been disclosed.

Note that, for example, Patent Document 1 is known as prior art document information related to the invention of this application.

International Publication No. 2006/070544

The above-mentioned conventional magnetic elements may not be sufficiently reliable as inductors. In view of the above, the present disclosure aims to provide inductors and the like with higher reliability.

The inductor according to one aspect of the present disclosure includes a current-carrying member made of a metal material, having a main body extending in a current-carrying direction and lead-out portions connected to both ends of the main body in the current-carrying direction, an exterior member formed of a magnetic material, covering the current-carrying member, and including opposing surfaces that face both ends of the current-carrying member and a bottom surface connecting the opposing surfaces, and a pair of electrode members connected to the lead-out portions, at least a portion of which is exposed from the exterior member, and bent from the opposing surfaces along the bottom surface, the electrode members having protrusions that protrude toward the exterior member, and the exterior member having recesses into which the protrusions are fitted.

In addition, a method for manufacturing an inductor according to one aspect of the present disclosure includes a current-carrying member made of a metal material and having a main body portion extending along the current-carrying direction and lead-out portions connected to both ends of the main body portion in the current-carrying direction, an exterior member formed of a magnetic material, covering the current-carrying member, and including opposing surfaces that face both ends of the current-carrying member and a bottom surface connecting the opposing surfaces, and a pair of electrode members that are connected to the lead-out portions and at least partially exposed from the exterior member and bent from the opposing surfaces along the bottom surface, the electrode members having protrusions that protrude toward the exterior member, and the exterior member having recesses into which the protrusions are fitted, and includes a punching process in which the current-carrying member and the pair of electrode members are integrally formed by punching a long, plate-like irregular cross-section strip with a protrusion formed along the longitudinal direction using a mold, and the protrusions of the irregular cross-section strip are formed to form the main body portion and the protrusions of the electrode members.

This disclosure provides a more reliable inductor.

FIG. 1 is a schematic perspective view showing a configuration of an inductor according to an embodiment of the present disclosure. FIG. 1 is a top view of an inductor according to an embodiment of the present disclosure. 1 is a side view of an inductor according to an embodiment of the present disclosure; 1 is a bottom view of an inductor according to an embodiment of the present disclosure; 1 is a side view of an opposing surface of an inductor according to an embodiment of the present disclosure; 3. A cross-sectional view taken along line iii-iii in FIG. FIG. 11 is a cross-sectional view illustrating another example of an inductor according to an embodiment of the present disclosure. A flowchart showing a method for manufacturing an inductor according to an embodiment of the present disclosure. FIG. 1 is a diagram illustrating a preparation process in a method for manufacturing an inductor according to an embodiment of the present disclosure. 10 is a cross-sectional view taken along line iv-iv in FIG. FIG. 1 is a diagram illustrating a punching process in a method for manufacturing an inductor according to an embodiment of the present disclosure. 4A to 4C are diagrams illustrating a punching process in a method for manufacturing an inductor according to an embodiment of the present disclosure. FIG. 1 is a diagram illustrating an exterior mounting process in a method for manufacturing an inductor according to an embodiment of the present disclosure. FIG. 1 is a diagram illustrating a finishing process in a method for manufacturing an inductor according to an embodiment of the present disclosure. FIG. 13 is a diagram illustrating a pressing process in another example of a method for manufacturing an inductor according to an embodiment of the present disclosure.

(Knowledge that led to disclosure)
The magnetic element disclosed in the above-mentioned Patent Document 1 includes a flat-plate-shaped current-carrying member and an exterior member covering a part of the current-carrying member, and the current-carrying member protruding from the exterior member is bent from the side to the bottom of the exterior member. The current-carrying member exposed from the exterior member functions as an electrode member. It is known that the stress of vibration is concentrated on the part of the electrode member protruding from the exterior member and bent toward the bottom when the magnetic element is mounted on a printed circuit board and subjected to vibration. It is also known that metal fatigue may occur if the stress of vibration is repeated for a long period of time. In other words, if the electrode member is simply along the side to the bottom of the exterior member as in the magnetic element disclosed in the above-mentioned Patent Document 1, sufficient vibration resistance may not be obtained. In other words, the magnetic element disclosed in Patent Document 1 may not have sufficient reliability as an inductor.

In this disclosure, therefore, a protrusion protruding toward the exterior member is provided on the electrode member, and a recess in the exterior member into which the protrusion fits, allowing the protrusion and the recess to interfere with each other and disperse the stress of vibration, thereby preventing the concentration of the stress of vibration on the part of the electrode member that protrudes from the exterior member and is bent toward the bottom surface, thereby providing a more reliable inductor.

One embodiment of the present disclosure will be described in detail below with reference to the drawings.

Note that each of the embodiments described below shows a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement positions, connection forms, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim are described as optional components.

In addition, in each drawing, an X-axis, a Y-axis, and a Z-axis, which indicate three mutually perpendicular directions, are shown, and these axes are used for explanation as necessary. Each axis is added for the purpose of explanation,
There is no limitation on the direction and attitude in which the inductor is used.

(Embodiment)
[composition]
First, an inductor according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 5. FIG.

Figure 1 is a schematic perspective view showing the configuration of an inductor according to an embodiment. Figure 1 shows the general shape of an exterior member 10 (e.g., a powder magnetic core) described below, and further shows the interior of the exterior member 10 in a see-through manner. For example, components such as the main body 40 and the lead-out portions 20 and 30 that are hidden by being embedded in the exterior member 10 are shown with dashed lines. In addition, the hidden outline of the exterior member 10 is shown with a two-dot chain line, indicating that it is visible through the exterior member 10.

2 to 5 are top, side, and bottom views of an inductor according to an embodiment, as well as a side view of the opposing surface 11, which will be described later. More specifically, FIG. 2 shows a top view of the inductor 100 when the top surface 14 is viewed from the positive side of the Z axis in FIG. 1, FIG. 3 shows a side view of the inductor 100 when the side surface 15 is viewed from the negative side of the Y axis in FIG. 1, FIG. 4 shows a bottom view of the inductor 100 when the bottom surface 13 is viewed from the negative side of the Z axis in FIG. 1, and FIG. 5 shows a side view of the inductor 100 when the opposing surface 11 is viewed from the negative side of the X axis in FIG. 1. In FIG. 2, FIG. 3, and FIG. 5, the interior of the exterior member 10 is shown in a see-through manner, as in FIG. 1.

As shown in Figures 1 to 5, the inductor 100 includes an exterior member 10, a main body 40, a first electrode member 25, and a second electrode member 35.

In this specification, the "first electrode member 25" and the "second electrode member 35" may be collectively referred to as the "electrode member."

As an example, the inductor 100 has a main body 40 disposed inside a rectangular exterior member 10 made of a metallic magnetic material and a resin material, and the approximate outer shape is determined by the shape of the exterior member 10. The exterior member 10 can be formed into any shape by molding. In other words, an inductor 100 of any shape can be realized depending on the shape of the exterior member 10 during molding. The inductor 100 is a passive element that stores the electrical energy flowing between the first electrode member 25 and the second electrode member 35 as magnetic energy by the main body 40.

The exterior member 10 is the outer shell of the inductor 100 that covers the main body 40 and the lead-out portions 20 and 30 described below, and is, for example, a powder magnetic core made of a metal magnetic powder and a resin material. The exterior member 10 may be made of any magnetic material, such as ferrite, or other materials.

For the metal magnetic powder, particulate materials having a predetermined elemental composition, such as Fe-Si-Al, Fe-Si, Fe-Si-Cr, or Fe-Si-Cr-B, are used. For the resin material, a material that can maintain a certain shape by binding the metal magnetic powder particles while insulating them, such as silicone, is selected. The exterior member 10 has substantially rectangular opposing surfaces 11, 12 (surfaces on both sides of the X-axis) on which the first electrode member 25 and the second electrode member 35 are respectively formed, and has a substantially rectangular prism shape with the four sides of each opposing surface 11, 12 connected to the top surface 14 (surface on the positive side of the Z-axis), the bottom surface 13 (surface on the negative side of the Z-axis), and two side surfaces 15, 16 (surfaces on both sides of the Y-axis).

In this embodiment, the inductor 100 has an exterior member 10 with, for example, a dimension of 5.0 mm in the X-axis direction, a dimension of 5.0 mm in the Y-axis direction, and a dimension of 3.0 mm in the Z-axis direction, but is not limited to this. As with the above shape, the inductor 100 can be realized in any size depending on the dimensions of the exterior member 10. Furthermore, the dimensions of the main body 40 and the electrode members 25, 35 may be determined according to the shape of the inductor 100.

The main body 40 is realized by a plate-shaped metal material 63 made of metals such as aluminum, copper, silver, and gold, as well as alloys of metals and other substances. The main body 40 extends along the current-carrying direction (the X-axis direction in the figure), and the lead-out portions 20 and 30 are connected to both ends. The main body 40 and the lead-out portions 20 and 30 are collectively referred to as the current-carrying member.

The lead-out portion 20 is connected to the first electrode member 25. The lead-out portion 30 is connected to the second electrode member 35. Details will be described later, but in this embodiment, the main body portion 40, the lead-out portions 20, 30, and the electrode members 25, 35 are integrally formed without any connecting portions. In other words, the main body portion 40, the lead-out portions 20, 30, and the electrode members 25, 35 are names given to each part formed by processing a single member made of the same material.

The first electrode member 25 and the second electrode member 35 are plate-shaped parts formed using the same material as the main body 40, and at least a portion of them is exposed from the exterior member 10. External electrical components, etc. are connected to these exposed portions to form an electrical product including the inductor 100.

The first electrode member 25 and the second electrode member 35 extend downward from the connection points with the lead-out portions 20 and 30 along the opposing surfaces 11 and 12 described above. The first electrode member 25 and the second electrode member 35 are bent in accordance with the bending of the opposing surfaces 11 and 12 and the bottom surface 13, and thus have a first contact 27 and a second contact 37 that further extend along the bottom surface 13. By arranging the contacts of the electrode members on the bottom surface 13 side in this manner, they can be directly connected to a land (not shown) of a mounting board or the like on which the inductor 100 is mounted.

In addition, in order to make it easier to fold the electrode members 25, 35, fold-facilitating portions 22, 23, 32, 33 may be provided that are formed of holes that penetrate the folded portions of the electrode members 25, 35.

In addition, to improve the fixing strength between the current-carrying member and the exterior member 10, anchor holes 24, 34 consisting of holes penetrating the lead-out portions 20, 30 may be provided.

Here, the first electrode member 25 has a protruding portion 28 that protrudes toward the opposing surface 11 of the exterior member 10, and a protruding portion 29 that protrudes toward the bottom surface 13 of the exterior member 10. The exterior member 10 has a recess 18 into which the protruding portion 28 and the protruding portion 29 are fitted.

The second electrode member 35 also has a protruding portion 38 that protrudes toward the opposing surface 12 of the exterior member 10, and a protruding portion 39 that protrudes toward the bottom surface 13 of the exterior member 10. The exterior member 10 has a recess 19 into which the protruding portion 38 and the protruding portion 39 fit.

In other words, the electrode members 25, 35 have protrusions 28, 29, 38, 39 that protrude toward the exterior member 10, and the exterior member 10 has recesses 18, 19 into which the protrusions 28, 29, 38, 39 fit.

The recesses 18, 19 may be provided in a state where they are connected to the opposing surfaces 11, 12 and the bottom surface 13 of the exterior member 10, or they may be provided separately so that the opposing surfaces 11, 12 and the bottom surface 13 are not connected.

As a result, when the inductor 100 is mounted on a printed circuit board and subjected to vibration, the protrusions 28, 29, 38, 39 interfere with the recesses 18, 19, dispersing the stress of the vibration and preventing the stress of the vibration from concentrating on the portions of the electrode members 25, 35 that protrude from the exterior member 10 and are bent toward the bottom surface 13.

The conductive member consisting of the main body 40 and the lead-out portions 20, 30, and the pair of electrode members 25, 35 may be an integral part formed by processing a long plate-like irregular cross-section strip 64 (see FIG. 9 described later) having one protrusion 66 along the longitudinal direction on one side. In this case, the main body 40, the protrusions 28, 29 of the first electrode member 25, and the protrusions 38, 39 of the second electrode member 35 are formed by the protrusion 66 on the irregular cross-section strip 64.

This allows the protrusions 28, 29, 38, and 39 to be easily configured and made smaller and stronger than when, for example, the protrusions are manufactured by pressing from the side opposite the exterior member of the electrode member.

The protrusions 28, 29, 38, 39 and main body 40, which are composed of such irregular cross-section strips 64, will be described with reference to Figure 6. Figure 6 is a cross-sectional view taken along line iii-iii in Figure 3. Figure 6 shows a cross-section of the inductor 100 cut in a plane that intersects with the current flow direction (for example, perpendicular to the current flow direction). In Figure 6, an overall cross-sectional view of the inductor 100 is shown on the left, and an enlarged cross-sectional view of the main body 40 and its vicinity is shown on the upper right. Also, an enlarged cross-sectional view of the second electrode member 35 and the protrusion 39 and its vicinity is shown on the lower right.

In FIG. 6, corresponding parts between the overall cross-sectional view and the enlarged cross-sectional view are connected by dashed lines to show the mutual relationship. Also, in FIG. 6, like FIG. 1, the components embedded in the exterior member 10 are shown in a see-through manner.

First, we will explain the second electrode member 35.

When viewed in cross section cut in a plane that intersects with the longitudinal direction of the irregular cross-section strip 64 (for example, perpendicular to the longitudinal direction), the second electrode member 35 is composed of the convex portion 66 of the irregular cross-section strip 64 and the plate portion 65.

At both corners of the protruding side of the protruding portion 39 (the positive side of the Z axis in FIG. 6), there may be a rounded R (radius) formed, which is a processing mark when the irregular cross-section strip 64 is manufactured by rolling processing or the like. Similarly, at the base side of the protruding portion 39 (the negative side of the Z axis in FIG. 6), there may be a R (radius) formed in the opposite direction to the both corners of the protruding side. In other words, the width of the protruding portion 39 (the Y axis direction in FIG. 6) may be narrower at the protruding tip side than at the center of the protruding height (the Z axis direction in FIG. 6), and wider at the base side than at the center of the protruding height.

The maximum thickness ET of the second electrode member 35 (Z-axis direction in FIG. 6) is the sum of the thickness of the plate portion 65 of the irregular cross-section strip 64 and the height of the protrusion 66 of the irregular cross-section strip 64. In the inductor 100 of this embodiment, for example, the protrusion height PH of the protrusion 39 is 0.4 mm, the width PW of the central portion of the protrusion height of the protrusion 39 is 0.6 mm, R is 0.2 mm, the thickness EB of the plate portion of the second electrode member 35 is 0.2 mm, and the maximum thickness ET of the second electrode member 35 is 0.6 mm, but is not limited to this. Any dimensions can be determined depending on the size of the inductor 100 and the strength of the vibration stress.

Note that we have described one example of the shape and dimensions of the protrusion 39 of the second electrode member 35, but the other protrusions 38, 28, and 29 are similar.

Next, we will explain the recess 19.

The recess 19 has a shape that allows the protrusions 38 and 39 to be fitted into it.

The width RW of the recess 19 (Y direction in FIG. 6) should be 1.2 times or more and 2.0 times or less the width PW of the center of the protrusion height of the protrusions 38, 39.

This makes it easier for the protrusions 38, 39 to interfere with the recess 19 when the inductor 100 is mounted on a printed circuit board and subjected to vibration.

If the width RW of the recess 19 is less than 1.2 times the width PW of the central portion of the protrusion height of the protrusions 38, 39, it is not preferable because it makes it difficult to fit the protrusions 38, 39 into the recess 19. Also, if it is more than 2.0 times, it is not preferable because it makes it difficult for the recess 19 and the protrusions 38, 39 to interfere with each other. More preferably, it is desirable to set the width RW to 1.2 times or more and 1.5 times or less.

Note that while an example of recess 19 has been described, the same applies to recess 18.

Furthermore, it is sufficient that either or both of the relationship between the recesses 18, 19 formed on the opposing surfaces 11, 12 and the protrusions 28, 38, and the relationship between the recesses 18, 19 formed on the bottom surface 13 and the protrusions 29, 39 have the width ratio relationship described above.

Next, we will explain the main body unit 40.

When viewed in cross section cut in a plane intersecting (for example, perpendicular to) the longitudinal direction of the irregular cross-section strip 64, the main body 40 is composed of at least the protruding portion 66 of the irregular cross-section strip 64. In the main body 40 shown in Figure 6, the protruding portion 66 of the irregular cross-section strip 64 protrudes in the opposite direction to the protruding portion 39 (the negative direction of the Z axis in Figure 6).

In the main body 40, a portion including the R (radius) on the base side of the convex portion 66 of the irregular cross-section strip 64 and the plate portion 65 of the irregular cross-section strip 64 are cut out using a formwork across the width of the main body 40 (the X-axis direction in FIG. 6). In other words, the cross-sectional shape of the main body 40 is machined so that its outer periphery has a quadrilateral cross section.

The maximum thickness BT of the main body 40 (Z-axis direction in FIG. 6) is the sum of the thickness of the plate portion 65 of the irregular cross-section strip 64 and the protruding height of the convex portion 66 of the irregular cross-section strip 64. In the inductor 100 of this embodiment, for example, the width BW of the main body 40 is 0.6 mm, and the maximum thickness BT of the main body 40 is 0.6 mm, but is not limited to this. Any dimensions can be determined depending on the magnitude of the current flowing through the inductor 100, etc.

Here, in the inductor 100, the maximum thickness BT of the body 40 can be 0.8 times or more and 1.2 times or less than the maximum thickness ET of the electrode members 25, 35 including the protrusions 28, 29, 38, 39. This means that the maximum thickness ET of the body 40 formed by the protrusion 66 of the irregular cross-section strip 64 is the same as that of the electrode members 25, 35 including the protrusions 28, 29, 38, 39. The above-mentioned relationship of 0.8 times or more and 1.2 times or less refers to the relationship when the body 40 and the electrode members 25, 35 are deformed during the manufacturing process of the inductor 100, and is more preferably 0.9 times or more and 1.1 times or less.

This allows the cross-sectional area of the main body 40 to be increased, suppressing the DC resistance loss of the inductor 100.

In addition, in a cross section intersecting the current flow direction, the main body 40 has a rectangular cross section, and the long side of the smallest rectangle 46 (shown by a dotted line in FIG. 6) into which the rectangular cross section fits can be greater than or equal to 1.0 times and less than or equal to 1.2 times the short side of the smallest rectangle 46.

As a result, when current is applied to the inductor 100, the magnetic path length of the magnetic flux that is formed to circulate around the main body 40 becomes shorter than when the cross section of the main body 40 has a flat rectangular cross section, improving the magnetic efficiency of the inductor 100, and more preferably, the relationship should be 1.0 times or more and 1.1 times or less.

Next, another example of an inductor 200 according to this embodiment will be described with reference to FIG. 7.

Figure 7 is a cross-sectional view showing another example of an inductor 100 according to an embodiment of the present disclosure.

The main difference between the inductor 100 and the inductor 200 of this embodiment is that the cross section of the body 40 of the inductor 100 is rectangular, whereas the cross section of the body 40 of the inductor 200 is circular.

In the following description of inductor 200, duplicate descriptions of configurations that are substantially identical to those of inductor 100 may be omitted.

Figure 7 shows a cross section of the inductor 200 from the same perspective as Figure 6. Also, in Figure 7, an overall cross section of the inductor 200 is shown on the left, and an enlarged cross section of the main body 40 area is shown on the right, with corresponding parts between the overall cross section and the enlarged cross section being connected by dashed lines to show their relationship to each other.

Inductor 200, another example of this embodiment, has a circular cross section that has been machined using press dies 55 and 57 (see FIG. 15, described later) so that the cross section approaches a circular shape when viewed in a cross section cut in a plane that intersects (for example, is perpendicular to) the current flow direction.

Here, the area S1 of the circular cross section of the main body 40 is 0.8 times or more and 1.0 times or less than the area S2 of the smallest perfect circle 47 (shown by a dotted line in Figure 7) into which the circular cross section can be accommodated.

As a result, compared to a rectangular cross section having the same cross-sectional area of the main body 40, a circular cross section shortens the magnetic path length of the magnetic flux circulating around the main body 40, thereby improving the magnetic efficiency of the inductor 200.

Next, we will explain the derivation sections 20 and 30.

As shown in Figures 1 to 6, the lead-out sections 20 and 30 are composed of the protruding portion 66 (thick portion) of the irregular cross-section strip 64 that is connected to the main body 40, and the plate portion 65 (thin portion) of the irregular cross-section strip 64 that is connected to the protruding portion 66. The plate portion 65 of the irregular cross-section strip 64 is connected to the electrode members 25 and 35.

Furthermore, a bending-facilitating portion 22 is formed in a region that spans the lead-out portion 20 and the first electrode member 25 and includes the convex portion 66 of the irregular cross-section strip 64. A bending-facilitating portion 32 is formed in a region that spans the lead-out portion 30 and the second electrode member 35 and includes the convex portion 66 of the irregular cross-section strip 64.

The easily bending portions 22, 32 are not limited to holes, as long as they make it easier to bend the first electrode member 25 and the second electrode member 35. For example, they may be notches that thin the protruding portion 66 of the irregular cross-section strip 64 (thick portion). Similarly, the easily bending portions 23, 33 may be notches.

[Production method]
Next, a method for manufacturing the above-mentioned inductor 100 will be described with reference to FIG. 8 and also with reference to FIGS.

Figure 8 is a flowchart showing a method for manufacturing the inductor 100 according to this embodiment.

In the manufacturing of the inductor 100 in this embodiment, first, the metal material 63 is prepared (preparation step S101).

Here, FIG. 9 is a diagram for explaining the preparation process of the manufacturing method of the inductor 100 according to the embodiment, and shows a perspective view of the metal material 63. Also, FIG. 10 is a cross-sectional view taken along line iv-iv in FIG. 9. Note that FIG. 9 is shown from a perspective where the Y-axis and Z-axis directions are reversed from those in FIG. 1.

As shown in Figures 9 and 10, in the preparation step S101, a modified cross-section strip 64 made of copper material is prepared as the metal material 63. The modified cross-section strip 64 has a long plate-shaped plate portion 65 and one protrusion portion 66 extending along the longitudinal direction on one surface of the plate portion 65. The modified cross-section strip 64 is, for example, a copper plate that is rolled to integrally process the plate portion 65 and the protrusion portion 66.

As an example of the dimensions of the metal material 63, the thickness Eb of the plate portion 65 is 0.2 mm, the height Ph of the protrusion 66 is 0.4 mm, and the width Pw of the center of the height of the protrusion 66 is 0.6 mm, but this is not limited to these.

Referring again to FIG. 8, following the preparation step S101, a form 62 is used to punch out the metal material 63 to integrally form the conductive members (main body 40, lead-out portions 20, 30) and electrode members 25, 35 (punching step S102).

Here, Figs. 11 and 12 are diagrams illustrating the punching process in the manufacturing method of an inductor according to one embodiment of the present disclosure, with Fig. 11 showing the state before punching and Fig. 12 showing the state after punching. Note that Figs. 11 and 12 are shown from the same perspective as Fig. 9.

As shown in Figures 11 and 12, in the punching process S102, a formwork 62 is used to punch out a metal material 63 consisting of an irregular cross-section strip 64 with a protrusion 66 formed along the longitudinal direction of a long plate-like plate portion 65, thereby integrally forming a conductive member and a pair of electrode members 25, 35, and the protrusion 66 of the irregular cross-section strip 64 forms the main body portion 40 and the protrusions 28, 29, 38, 39 of the electrode members 25, 35.

As shown in FIG. 12, the main body 40 is formed by punching out, leaving only the protruding portion 66. The electrode members 25 and 35 are formed by punching out, including the plate portion 65 and the protruding portion 66, and the protruding portion 66 constitutes the protruding portions 28, 29, 38, and 39.

In addition, in the case of forming the bending easy portions 22, 23, 32, and 33, the punching step S10
2.

Referring again to FIG. 9, following the punching step S102, the conductive members (main body 40, lead-out portions 20, 30) are covered with the exterior member 10 (exterior step S103).

Here, FIG. 13 is a diagram illustrating the exterior mounting process of the inductor manufacturing method according to the embodiment.

Figure 13 shows the inductor 100 during the packaging process S103, and is shown from the same perspective as Figure 9. That is, the bottom surface 13 of the packaging member 10 is shown at the top of the page, and the top surface 14 is shown at the bottom of the page.

As shown in FIG. 13, in the exterior packaging process S103, the processed conductive members (main body 40, lead-out portions 20, 30) are coated with a powder magnetic core from the metal material 63 to determine the outer shape of the inductor 100.

In this exterior application step S103, recesses 18, 19 are formed on the opposing surfaces 11, 12 and bottom surface 13 of the exterior member 10, into which the protrusions 28, 29, 38, 39 fit when the electrode members 25, 35 are folded in the finishing step S104 described below.

After the exterior member 10 is formed, the electrode members 25, 35 are cut to a predetermined length, and the surfaces are solder-plated, etc., as necessary.

Referring again to FIG. 8, following the exterior packaging process S103, the first electrode member 25 and the second electrode member 35 are folded (finishing process S104).

Here, FIG. 13 is a diagram for explaining the finishing step in the manufacturing method of the inductor according to the embodiment. FIG. 13 shows the inductor 100 in the finishing step S104 from the same perspective as FIG. 3. Also, like FIG. 3, the components embedded in the exterior member 10 are shown in a see-through manner.

As shown in FIG. 13, the first electrode member 25 and the second electrode member 35 shown by the dotted lines in the figure are folded so as to align with the exterior member 10.

By bending in this finishing process S104, the protrusions 28, 29, 38, and 39 are fitted into the recesses 18 and 19. The first contact 27 and the second contact 37 are also formed. In this manner, the inductor 100 according to the embodiment is manufactured.

Next, a method for manufacturing the inductor 200 shown as another example of this embodiment will be described with reference to FIG.

The main difference between the manufacturing method of inductor 100 and the manufacturing method of inductor 200 in this embodiment is that, in addition to the manufacturing method of inductor 100, a pressing process is included after the punching process S102 and before the exterior mounting process S103, in which press dies 55 and 57 are used to mold the cross section of main body 40 that intersects with the current flow direction into a circular cross section.

In the following description of the manufacturing method for inductor 200, the description of the configuration and manufacturing method that are substantially the same as those of inductor 100 may be omitted.

FIG. 15 is a diagram illustrating a pressing step in another example of a method for manufacturing an inductor according to an embodiment.

Figure 15 shows cross sections of the main body 40 being press-processed in the order of (a) to (c). Note that the main body 40 shown in Figure 15 corresponds to the cross section of the main body 40 shown in Figure 7, and shows how the cross section is deformed by processing.

First, FIG. 15(a) shows the main body 40 having a rectangular cross section punched out in the punching process S102, and the press dies 55 and 57.

In the pressing process, the main body 40 is pressed in a direction intersecting the current flow direction using press dies 55 and 57. Press dies 55 and 57 are prepared with dies 56 and 58 having semicircular cross sections, respectively.

Molds 56 and 58 are prepared so that when they are brought together in the direction of the white arrow, the area of the circular space is 1.0 to 1.1 times the area of the rectangular cross section of main body 40.

This allows the cross section of the main body 40 formed by pressing to become closer to a circle.

Next, as shown in FIG. 15(b), pressing dies 55 and 57 are brought together in the direction of the white arrows to form a space with a circular cross section using dies 56 and 58. The main body 40 is placed in this space and pressed. In this way, the cross section of the main body 40 is shaped from a square shape to something closer to a circular shape using dies 56 and 58.

Next, as shown in FIG. 15(c), the press dies 55 and 57 are opened in the direction of the white arrows to remove the pressed main body 40.

After the pressing process, similar to the manufacturing method of the inductor 100, the exterior packaging process S103 and the finishing process S104 are carried out in order to manufacture the inductor 200, which is another example of the present embodiment.

[Effects, etc.]
As described above, the inductor 100 according to this embodiment comprises: a current-carrying member made of metal material 63, having a main body portion 40 extending in the current-carrying direction, and lead-out portions 20, 30 connected to both ends of the main body portion 40 in the current-carrying direction; an exterior member 10 formed using a magnetic material, covering the current-carrying member, and including opposing surfaces 11, 12 facing each other at both ends of the current-carrying member, and a bottom surface 13 connecting the opposing surfaces 11, 12; and a pair of electrode members 25, 35 connected to the lead-out portions 20, 30, at least a portion of which is exposed from the exterior member 10, and bent from the opposing surfaces 11, 12 along the bottom surface 13, with the electrode members 25, 35 having protrusions 28, 29, 38, 39 protruding toward the exterior member 10, and the exterior member 10 having recesses 18, 19 into which the protrusions 28, 29, 38, 39 are fitted.

When the inductor 100 is mounted on a printed circuit board and subjected to vibration, the protrusions 28, 29, 38, 39 interfere with the recesses 18, 19, dispersing the stress of the vibration and preventing the stress of the vibration from concentrating on the portions of the electrode members 25, 35 that protrude from the exterior member 10 and are bent toward the bottom surface 13. This makes it possible to realize a more reliable inductor 100.

Also, for example, the conductive member and the pair of electrode members 25, 35 are an integral body consisting of a long, plate-shaped irregular cross-section strip 64 having a convex portion 66 along the longitudinal direction, and the main body 40 and the protrusions 28, 29, 38, 39 of the electrode members 25, 35 may be part of the convex portion 66 in the irregular cross-section strip 64.

This makes it easier to configure the protrusions 28, 29, 38, and 39, and also makes them smaller and stronger, compared to when the protrusions are manufactured by pressing the electrode member from the side opposite the exterior member. As a result, a more reliable inductor 100 can be more easily realized.

Also, for example, the maximum thickness BT of the main body 40 may be 0.8 times or more and 1.2 times or less than the maximum thickness ET of the electrode members 25, 35 including the protrusions 28, 29, 38, and 39.

This increases the cross-sectional area of the main body 40, suppressing the DC resistance loss of the inductor 100. This makes it possible to realize an inductor 100 with even smaller losses.

For example, in a cross section intersecting the current flow direction, the main body has a rectangular cross section, and the long side of the smallest rectangle 46 into which the rectangular cross section fits may be 1.0 times or more and 1.2 times or less than the short side of the smallest rectangle.

As a result, when current is applied to the inductor 100, the magnetic path length of the magnetic flux that is formed to circulate around the main body 40 is shorter than when the cross section of the main body 40 has a flat rectangular cross section, improving the magnetic efficiency of the inductor 100. This allows for a higher performance inductor 100 to be realized.

For example, in a cross section intersecting the current flow direction, the main body 40 may have a circular cross section, and the area of the circular cross section may be 0.9 times or more and 1.0 times or less than the area of the smallest perfect circle 47 into which the circular cross section can be contained.

As a result, compared to a rectangular cross section having the same cross-sectional area of the main body 40, a circular cross section can shorten the magnetic path length of the magnetic flux circulating around the main body 40, thereby improving the magnetic efficiency of the inductor 200. As a result, a high-performance inductor 200 can be realized.

In addition, the manufacturing method of the inductor 100 in this embodiment includes a current-carrying member made of a metal material 63, having a main body portion 40 extending along the current-carrying direction and lead-out portions 20, 30 connected to both ends of the main body portion 40 in the current-carrying direction, an exterior member 10 formed using a magnetic material, covering the current-carrying member and including opposing surfaces 11, 12 facing each other at both ends of the current-carrying member and a bottom surface 13 connecting the opposing surfaces 11, 12, and a pair of electrode members 25, 35 connected to the lead-out portions 20, 30, at least a portion of which is exposed from the exterior member 10, and which bend from the opposing surfaces 11, 12 along the bottom surface 13, The electrode members 25, 35 have protrusions 28, 29, 38, 39 that protrude toward the exterior member 10, and the exterior member 10 has recesses 18, 19 into which the protrusions 28, 29, 38, 39 are fitted. This method for manufacturing an inductor 100 includes a punching process in which a long plate-like irregular cross-section strip 64 having a protrusion 66 formed along the longitudinal direction is punched out using a mold 62 to integrally form a conductive member and a pair of electrode members 25, 35, and the protrusions 28, 29, 38, 39 of the electrode members 25, 35 are formed by the protrusions 66 of the irregular cross-section strip 64.

According to this, the conductive members (main body 40, electrode members 25, 35) and protrusions 28, 29, 38, 39 can be integrally formed at one time simply by punching out the metal material 63 consisting of the irregular cross-section strip 64 with the form 62. Therefore, the inductor 100 with higher reliability can be manufactured by a simple process.

It may also include a pressing process in which, for example, press dies 55 and 57 are used to mold the cross section of the main body 40 that intersects with the current flow direction into a circular shape.

As a result, the magnetic path length of the inductor 100 can be improved and the magnetic efficiency can be increased simply by pressing the main body 40. Therefore, a higher performance inductor 200 can be manufactured with simple processing.

(Other embodiments, etc.)
Although the inductors and the like according to the embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments.

For example, the present invention also includes electrical products or electrical circuits that use the inductor described above. Examples of electrical products include power supply devices equipped with the inductor described above.

Furthermore, the present disclosure is not limited to this embodiment. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to this embodiment and forms constructed by combining components of different embodiments may also be included within the scope of one or more aspects.

The inductor disclosed herein is useful as a high-frequency inductor.

10 Exterior member 11 Opposing surface 12 Opposing surface 13 Bottom surface 14 Top surface 15 Side surface 16 Side surface 18 Recess 19 Recess 20 Lead-out portion 22 Easily bendable portion 23 Easily bendable portion 24 Anchor hole 25 First electrode member 27 First contact 28 Protruding portion 29 Protruding portion 30 Lead-out portion 32 Easily bendable portion 33 Easily bendable portion 34 Anchor hole 35 Second electrode member 37 Second contact 38 Protruding portion 39 Protruding portion 40 Main body portion 46 Minimum rectangle 47 Minimum perfect circle 55 Press die 57 Press die 56 Die 58 Die 62 Formwork 63 Metal material 64 Deformed cross-section strip 65 Plate portion 66 Convex portion 100 Inductor 200 Inductor

Claims (6)

a current-carrying member made of a metal material, the current-carrying member having a main body portion extending along a current-carrying direction and lead-out portions connected to both ends of the main body portion in the current-carrying direction;
an exterior member formed of a magnetic material, covering the current-carrying member, the exterior member including opposing surfaces that face each other at both ends of the current-carrying member, and a bottom surface that connects the opposing surfaces;
a pair of electrode members connected to the lead-out portion, at least a portion of which is exposed from the exterior member, and which are bent from the opposing surface along the bottom surface;
The electrode member has a protruding portion protruding toward the exterior member,
The exterior member has a recess into which the protrusion is fitted,
The current-carrying member and the pair of electrode members are integral members each having a long plate-like irregular cross-section having a protrusion along the longitudinal direction,
The main body and the protrusion of the electrode member are convex portions of the irregular cross section strip .
Inductor. The maximum value of the thickness of the main body portion is, relative to the maximum value of the thickness of the electrode member including the protruding portion,
The relationship is 0.8 times or more and 1.2 times or less.
2. The inductor of claim 1 . In a cross section intersecting the current flow direction, the main body has a rectangular cross section,
The long side of the smallest rectangle into which the rectangular cross section can be accommodated is 1.0 times or more and 1.2 times or less than the short side of the smallest rectangle.
The inductor according to claim 1 or 2 . In a cross section intersecting the current flow direction, the main body has a circular cross section,
The area of the circular cross section is 0.9 times or more and 1.0 times or less than the area of the smallest perfect circle into which the circular cross section can be accommodated.
The inductor according to any one of claims 1 to 3 . a current-carrying member made of a metal material, the current-carrying member having a main body portion extending along a current-carrying direction and lead-out portions connected to both ends of the main body portion in the current-carrying direction;
an exterior member formed of a magnetic material, covering the current-carrying member, the exterior member including opposing surfaces that face each other at both ends of the current-carrying member, and a bottom surface that connects the opposing surfaces;
a pair of electrode members connected to the lead-out portion, at least a portion of which is exposed from the exterior member, and which are bent from the opposing surface along a bottom surface;
The electrode member has a protruding portion protruding toward the exterior member,
The exterior member has a recess into which the protrusion is fitted,
The method includes a punching process in which a mold is used to punch out a long plate-like irregular cross-section strip having a protrusion formed along the longitudinal direction thereof, thereby integrally forming the current-carrying member and the pair of electrode members, and the protrusions of the irregular cross-section strip are used to form the main body and the protrusions of the electrode members.
A method for manufacturing an inductor. A pressing process is included in which a cross section of the main body portion intersecting the current flow direction is formed into a circular shape using a press die.
The method for manufacturing the inductor according to claim 5 .