JP2022070058A - Inductor - Google Patents

Abstract

To provide an inductor having higher connection reliability.SOLUTION: An inductor 100 comprises: a three-dimensional magnetic core 10 having a lateral face 12; a coil element 20 which has an end portion 22 exposed from the magnetic core 10; an electrode member 30 arranged at an opposite side to the magnetic core 10 across the end portion 22; and a conductive bonding material 40 bonding the end portion 22 and the electrode member 30 with each other. The electrode member 30 has a lateral plate 36 which is arranged along the lateral face 12 of the magnetic core 10 and comprises a first-direction slit 31 comprised of a long hole which makes principal surfaces of the lateral plate 36 communicate each other while being lengthwise in a first direction along the lateral face 12. The end portion 22 extends in the first direction on the lateral face 12 and is overlapped with the first-direction slit 31 in the communication direction of both principal surfaces. The bonding material 40 is arranged inside the first-direction slit 31.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to inductors.

An inductor, which is a passive element that stores electrical energy as magnetic energy, is used in, for example, a DC-DC converter device for the purpose of raising and lowering a power supply voltage and smoothing a direct current. For example, a surface mount inductor that can be bonded on a circuit board by a reflow method has also been developed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-249770

Conventional inductors may lack connection reliability with external elements. In view of the above, it is an object of the present disclosure to provide an inductor with higher connection reliability.

The inductor according to one aspect of the present disclosure includes a magnetic material, a three-dimensional magnetic core having side surfaces, a metal material, and a coil having an embedded portion embedded in the magnetic core and an end exposed from the magnetic core. Conductive joining that joins an element, an electrode member containing a metal material and arranged on the opposite side of the magnetic core with the end of the coil element, and the end of the coil element and the electrode member. The electrode member is a side plate arranged along the side surface of the magnetic core, and has a length that communicates both main surfaces of the side plate in a long shape in a first direction along the side surface. It has a side plate provided with a first-direction slit formed of a hole, the end portion of the coil element extends on the side surface along the first direction, and the end portion extends in the communication direction of both main surfaces. It overlaps the first-way slit and the bonding material is arranged inside the first-way slit.

According to the present disclosure, it is possible to provide an inductor having higher connection reliability.

FIG. 1 is a cross-sectional view of an inductor according to a comparative example. FIG. 2 is a perspective view of the inductor according to the embodiment. FIG. 3 is a perspective view showing a first alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 4 is a first perspective view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 5 is a second perspective view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 6 is a plan view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 7 is a perspective view showing a third alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 8 is a flowchart showing a method of manufacturing an inductor according to an embodiment.

(Background to this disclosure)
As mentioned above, inductors have been used in many electronic devices in recent years. In particular, inductors are sometimes mounted on circuit boards and used, and surface mount inductors and the like that are premised on mounting on lands on circuit boards have also been developed.

For example, FIG. 1 is a cross-sectional view of a surface mount type inductor 100x according to a comparative example. The inductor 100x shown in FIG. 1 is similar to the inductor of Patent Document 1, and includes a coil element 20x, a magnetic core 10x surrounding the coil element 20x, and an electrode member 30x connected to the coil element 20x. The coil element 20x has an embedded portion 21x embedded in the magnetic core 10x, and an end portion 22x that protrudes outward from the side surface of the magnetic core 10x and is exposed. The end portion 22x of the coil element 20x is bent along the side surface of the magnetic core 10x and extends toward the bottom surface (the surface along the lower side of the paper surface).

The electrode member 30x is arranged on the side surface of the magnetic core 10x so as to overlap the outside of the end portion 22x of the coil element 20x, and is further bent along the bottom surface of the magnetic core 10x. The electrode member 30x and the end portion 22x are joined by a joining material (not shown). Here, the end portion 22x and the electrode member 30x are joined by a joining material before being bent along the bottom surface of the magnetic core 10x, and are bent along the bottom surface of the magnetic core 10x after joining. Therefore, after the end portion 22x and the electrode member 30x are bent, the bonding state cannot be visually confirmed by the outer electrode member 30x. Therefore, for example, it may not be possible to detect an abnormality in the joining state such as a shortage of the joining material or, due to this, a crack may occur in the joining portion or the joining portion may come off during the bending process.

When the inductor 100x is used, if there is an abnormality in the connection between the coil element 20x and the electrode member 30x as described above, the power is not sufficiently supplied to the coil element 20x and the expected performance cannot be obtained. In addition, it is expected that the electrical resistance of the joint will increase, causing problems such as abnormal heat generation.

Therefore, in the present disclosure, in view of the above, an inductor having higher connection reliability will be described. Specifically, the inductor according to the present disclosure includes a magnetic material, a three-dimensional magnetic core having side surfaces, a metal material, an embedded portion embedded in the magnetic core, and a coil having an end exposed from the magnetic core. It includes an element, an electrode member containing a metal material and arranged on the side opposite to the magnetic core with the end of the coil element interposed therebetween, and a conductive bonding material for joining the end of the coil element and the electrode member. The electrode member is a side plate arranged along the side surface of the magnetic core, and is provided with a first-direction slit formed of an elongated hole that communicates both main surfaces of the side plate in a long shape in the first direction along the side surface. It has a side plate, the end of the coil element extends on the side surface along the first direction, and overlaps the first direction slit in the communication direction of both main surfaces, and the bonding material is the first direction slit. It is located inside the.

The presence of the first-direction slit makes it possible to visually recognize the alignment between the end portion of the coil element and the electrode member and the bonding state between the end portion of the coil element and the electrode member. As a result, the occurrence of abnormalities in the joining between the end of the coil element and the electrode member is suppressed, and higher connection reliability is ensured.

Hereinafter, embodiments will be described more specifically with reference to the drawings.

It should be noted that all of the embodiments described below show a specific example of the present disclosure. The numerical values, shapes, materials, components, arrangement positions of the components, connection modes, steps, the order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. Further, among the components in the following embodiments, the components not described in the independent claims are described as arbitrary components.

In addition, each figure shows an X-axis, a Y-axis, and a Z-axis which mean three directions orthogonal to each other, and these axes and the axial directions along the axes are used for explanation as needed. In the following description, the Z-axis direction may be expressed as the first direction, and the X-axis direction may be expressed as the second direction. It should be noted that each axis is attached for the purpose of explanation, and does not limit the direction and orientation in which the inductor is used.

(Embodiment)
[Constitution]
The inductor in the embodiment will be described with reference to FIG.

FIG. 2 is a perspective view of the inductor according to the embodiment. In FIG. 2, the configuration seen from the outside of the inductor 100 according to the embodiment is shown by a solid line. Further, in FIG. 2, a broken line shows a configuration that can be seen when the magnetic core 10 of the inductor 100 is transmitted. Note that FIG. 2A shows the entire inductor 100, and FIG. 2B shows an enlarged view of the periphery of the first-direction slit 31. Further, in FIG. 2A, the illustration of the bonding material 40 as shown by dot hatching is omitted in FIG. 2B for the sake of explanation, but FIG. 2A is shown in FIG. It will be described assuming that the same bonding material 40 is located at the same position as in (b).

As shown in FIG. 2, the inductor 100 according to the embodiment includes a magnetic core 10, a coil element 20, an electrode member 30, and a bonding material 40.

As an example, the inductor 100 is a rectangular parallelepiped dust core, and the approximate outer shape is determined by the shape of the magnetic core 10. The magnetic core 10 can be formed into an arbitrary shape by molding. That is, the inductor 100 having an arbitrary shape can be realized depending on the shape of the magnetic core 10 at the time of molding. The inductor 100 of the present embodiment is composed of a magnetic core 10 having a dimension in the X-axis direction of 4 mm or more and 12 mm or less, a dimension in the Y-axis direction of 4 mm or more and 12 mm or less, and a dimension in the Z-axis direction of 2 mm or more and 8 mm or less.

The magnetic core 10 is an outer shell portion of the inductor 100 and covers a part of the coil element 20. The magnetic core 10 is, for example, a dust core made of a metal magnetic material powder, a resin material, or the like. The magnetic core 10 may be formed by using a magnetic material, ferrite or the like may be used, or may be other than that. As the metal magnetic powder, a particulate material having a predetermined elemental composition such as Fe—Si—Al system, Fe—Si system, Fe—Si—Cr system, or Fe—Si—Cr—B system is used. Further, as the resin material, a material that can maintain a certain shape by binding the particles of the metallic magnetic material powder such as silicone while insulating the particles is selected.

The magnetic core 10 has, for example, a rectangular parallelepiped shape, and has a bottom surface 13, four side surfaces connected to the bottom surface 13, and a top surface 14 connected to the four side surfaces and facing the bottom surface 13. The four side surfaces are composed of two side surfaces 11 facing each other in the X-axis direction and two side surfaces 12 facing each other in the Y-axis direction. Each of the four side surfaces 11 and 12 has a flat surface orthogonal to the bottom surface 13. It should be noted that the side surface 11 and the side surface 12 intersect, and the magnetic core 10 is located at the corner of the top surface 14 side (plus side in the Z-axis direction) from any of the side surface 11, the side surface 12, and the top surface 14. A notch portion 15 that is concave toward the inside is provided. Four notches 15 are formed corresponding to each of the combinations of the two side surfaces 11 and the two side surfaces 12. The function of the notch portion 15 will be described later together with the description of the electrode member 30.

The coil element 20 has a buried portion 21 and a plurality of end portions 22 connected to the buried portion. The coil element 20 of the present embodiment is composed of one embedded portion 21 and two end portions 22. The coil element 20 is realized by a material selected from a metal material such as aluminum, copper, silver, and gold, and an alloy composed of a metal and another substance. The buried portion 21 and the end portion 22 are names given to each part formed by processing one member made of the same material.

The end portion 22 is a portion that is not covered by the magnetic core 10 and is exposed from the side surface 12 of the magnetic core 10. The end portion 22 is extended in a flat plate shape having a thickness of, for example, about 0.1 to 0.2 mm, and extends along the side surface 12 toward the bottom surface 13 (that is, along the Z-axis direction). It is interrupted before reaching the bottom surface 13. That is, the end portion 22 is a portion arranged on the side surface 12 of the coil element 20.

The buried portion 21 is a portion covered by the magnetic core 10. The buried portion 21 is wound with a long material and functions as a coil. The number of turns of the buried portion 21 is not particularly limited, and is appropriately adjusted to the performance required for the inductor 100 such as 0.5 turn, 10 turns, or 100 turns, and the size of the magnetic core 10. Be selected. The buried portion 21 is formed, for example, by bending a copper wire. The cross section of the copper wire constituting the buried portion 21 is circular with a diameter of 0.16 to 1.40 mm, and the aspect ratio of the cross section (cross section) of the copper wire is 1: 1.

The buried portion 21 is arranged so that the wound winding shaft is along the Z-axis direction. The buried portion 21 has a curved portion formed by winding, and a straight portion connecting the curved portion and the end portion 22. The straight portion of the buried portion 21 extends in the Y-axis direction toward the side surface 12 of the magnetic core 10 in which the end portion 22 is arranged, and is connected to the end portion 22.

The electrode member 30 has a side plate 36, a bottom plate 34, and a locking portion 33. The electrode member 30 is realized by a material selected from a metal material such as aluminum, copper, silver, and gold, and an alloy composed of a metal and another substance. One electrode member 30 is provided on each side of the inductor 100 in the Y-axis direction, corresponding to each of the two end portions 22. Here, one of the two electrode members 30 will be described, but the two electrode members 30 have the same configuration to which the same description applies to the other. The side plate 36, the bottom plate 34, and the locking portion 33 are names given to each portion formed by processing one member made of the same material.

The side plate 36 is a portion provided along the side surface 12 corresponding to the side surface 12 of the magnetic core 10. The side plate 36 is arranged so as to overlap the end portion 22 of the coil element 20, and is fixed to the end portion 22 by a joint described later. The side plate 36 is configured to absorb the thickness of the end portion 22 at the portion overlapping the end portion 22 so that the portion not overlapping with the end portion 22 faces the side surface 12 of the magnetic core 10.

More specifically, the side plate 36 has a first region 32a in which the side plate 36 and the side surface 12 face each other so that the end portion 22 of the coil element 20 does not intervene between the side plate 36 and the side surface 12. Further, the side plate 36 is a second region 32b different from the first region 32a described above, and the second region 32b where the side plate 36 and the side surface 12 face each other via the end portion 22 of the coil element 20. Has. That is, the second region 32b of the side plate 36 faces the end portion 22 of the coil element 20. The second region 32b is arranged so as to be offset from the side surface 12 with respect to the first region 32a, and is concave in the direction away from the side surface 12 by the first region 32a and the second region 32b. A recess 32 is formed.

As shown in the figure, the recess 32 in the present embodiment is formed by a second region 32b sandwiched in the X-axis direction in two first regions 32a. Further, the concave portion 32 has a pocket shape in which the negative side in the Z-axis direction of the end portion 22 is closed and the positive side in the Z-axis direction is open. Further, by accommodating the end portion 22 in the recess 32, the electrode member 30 is suppressed from moving in the XZ plane via the recess 32. Specifically, when a force in the Z-axis positive direction is applied to the electrode member 30, the end portion 22 is caught on the Z-axis negative side surface in the internal space of the recess 32, so that the movement of the electrode member 30 is suppressed. Will be done. Further, when a force in the X-axis direction is applied to the electrode member 30, the end portion 22 is caught on both surfaces in the Z-axis direction in the internal space of the recess 32, so that the movement of the electrode member 30 is suppressed and the magnetic core. The alignment of the electrode member 30 with respect to 10 becomes easy.

By arranging the electrode member 30 so that the end portion 22 is in contact with or close to the surface of the second region 32b on the magnetic core 10 side (hereinafter, also referred to as the bottom of the recess 32), the end portion is arranged in the internal space of the recess 32. 22 is housed. The depth of the recess 32 (the size of the internal space in the Y-axis direction) is, for example, 0.1 to 0.6 mm, and most of the end 22 can be accommodated according to the thickness of the end 22. The appropriate depth is selected. As an example, the side plate 36 according to the present embodiment has a recess 32 having a depth of 0.2 mm. By accommodating the end portion 22 in the recess 32, the dead space between the side plate 36 and the side surface 12 is reduced, and a compact inductor 100 can be realized. Further, when the side plate 36 of the electrode member 30 comes into contact with the end portion 22 and the side surface 12 of the coil element 20, the physical connection between the electrode member 30 and the magnetic core 10 is stabilized.

The side plate 36 is formed with a first-direction slit 31. The first-direction slit 31 is formed of an elongated hole in the Z-axis direction (first direction), and communicates both the plus side and minus side main surfaces of the side plate 36 in the Y-axis direction. The first-direction slit 31 reaches the bottom of the recess 32 by communicating both main surfaces of the side plate 36. That is, the first-direction slit 31 is provided at the bottom of the recess 32.

Further, in the drawing, the end portion 22 overlaps the first direction slit 31 in the communication direction of both main surfaces of the side plates 36, which is a direction parallel to the Y-axis direction. More specifically, when the end portion 22 comes into contact with the main surface of the side plate 36 on the positive side in the Y-axis direction, the end portion 22 closes the first-direction slit 31. Further, when the end portion 22 is close to the main surface of the side plate 36 on the plus side in the Y-axis direction, the end portion 22 eliminates the large hole of the first-direction slit 31 in the communication direction and runs along the XZ plane from the end portion 22. A slight gap remains in the direction. The first-direction slit 31 will be described in more detail later.

The bottom plate 34 is a portion provided corresponding to the bottom surface 13 of the magnetic core 10. The bottom plate 34 is integrated with the side plate 36 at a position corresponding to the boundary between the side surface 12 of the magnetic core 10 and the bottom surface 13, and is provided along the bottom surface 13 so as to extend toward the center of the magnetic core 10. For example, when the inductor 100 is mounted on a circuit board, the bottom plate 34 is connected to a land on the circuit board via a joining material different from the joining material 40. At this time, a fillet made of the joining material used for connecting to the land is formed on the side plate 36.

The locking portion 33 is a protrusion portion that intersects the XZ plane on which the side plate 36 extends and projects in a direction parallel to the bottom plate 34. The locking portion 33 has a function of suppressing the movement of the electrode member 30 in the XZ plane. The locking portion 33 projects from the side plate 36 toward the magnetic core 10 side, and is locked to the notch portion 15 of the magnetic core 10 described above. Two locking portions 33 are provided for the electrode member 30, and each is locked in one notch portion 15. The four notch portions 15 provided in the magnetic core 10 described above are used for locking the two locking portions 33 provided in the two electrode members 30, respectively.

Hereinafter, two locking portions 33 provided on one electrode member 30 will be described with reference to the two locking portions 33. One of the two locking portions 33 is locked to the two notched portions 15 corresponding to the side surface 12 to which the electrode member 30 is attached. At this time, the width of the magnetic core 10 recessed in the X-axis direction from each of the two side surfaces 11 by forming the two notched portions 15 corresponds to the distance between the two locking portions 33.

Therefore, when a force in the X-axis plus direction is applied to the electrode member 30, one of the two locking portions 33 is caught on the surface on the X-axis plus side of one of the two notch portions 15, so that the electrode member 30 Movement is suppressed. Further, when a force in the minus direction of the X axis is applied to the electrode member 30, the other of the two locking portions 33 is caught on the surface of the other of the two notches 15 on the minus side of the X axis, so that the electrode member 30 Movement is suppressed. By locking the locking portion 33 to the notch portion 15 in this way, the movement of the electrode member 30 in the X-axis direction is suppressed.

Further, the height of the magnetic core 10 recessed in the Z-axis direction from the top surface 14 by forming the notch portion 15 corresponds to the distance between the locking portion 33 and the bottom plate 34. Therefore, when a force in the negative direction of the Z axis is applied to the electrode member 30, the two locking portions 33 are caught on the surface on the negative side of the Z axis in the two notch portions 15, so that the movement of the electrode member 30 is suppressed. Will be done. When a force in the plus direction of the Z axis is applied to the electrode member 30, the bottom plate 34 is caught on the bottom surface 13, so that the movement of the electrode member 30 is suppressed. In this way, the presence of the locking portion 33 suppresses the movement of the electrode member 30 in the XZ plane, so that the magnetic core 10 is restricted by the contact between the recess 32 and the end portion 22. The alignment of the electrode member 30 with respect to the electrode member 30 becomes easy.

Due to the relationship between the notch portion 15 and the locking portion 33, for example, the movement of the electrode member 30 is partially suppressed even in the absence of the joining member 40. The notch portion 15 and the locking portion 33 may be configured to suppress the movement of the electrode member 30 with respect to the magnetic core 10 in the negative side in the Y-axis direction. Specifically, the Z-axis minus side surface of the notch portion 15 is configured so that the plus side is closer to the bottom surface 13 side than the Y-axis direction minus side, and the locking portion 33 corresponds to this. It suffices if it is bent to the minus side in the Z-axis direction.

It is also possible to limit the movement of the electrode member 30 by inserting a protrusion into the recessed portion provided in the middle of the magnetic core 10 in the Z-axis direction without providing the notch portion 15. However, in this case, the conductive member is present in the middle of the magnetic core 10. Therefore, when the inductor 100 is used, the magnetic flux may be partially blocked and the magnetic characteristics of the inductor 100 may deteriorate. Therefore, it is effective to provide the notch portion 15 to lock the locking portion 33.

The bonding material 40 is a conductive material such as solder or silver brazing that can be melted and has high wettability to the coil element 20 and the electrode member 30. The joining material 40 is arranged in the first direction slit 31. The joining material 40 is solidified by cooling, and the wet surfaces of the side plate 36 and the end portion 22 are joined to each other to make them electrically conductive. Here, when the joining material 40 is sufficiently supplied, the first-way slit 31 is filled with the joining material 40 as shown in the figure.

For example, when manufacturing the inductor 100, before joining the electrode member 30 to the end portion 22, after observing the overlapping state of the first-direction slit 31 and the electrode member 30, joining them in an appropriate positional relationship. The material 40 can be used for joining. In addition, even after joining, it is possible to visually confirm the presence or absence of abnormalities in joining. As a result, poor bonding between the end portion 22 and the electrode member 30 as described above is suppressed.

Further, even when the supply amount of the joining material 40 is small, the liquid joining material 40 first provides a fillet between the end portion 22 and the inner surface surface (the surface along the Y-axis direction) of the first direction slit 31. Since it is formed, it can be visually determined whether or not it is normally joined after joining. By providing the first-direction slit 31 in this way, it is possible to perform the joining after visually confirming the alignment between the end portion 22 and the electrode member 30, and the end portion 22 involved in the joining can be performed. The wet surface between the electrode member 30 and the electrode member 30 can be enlarged, and the bonding state after bonding can be visually confirmed. Further, the longitudinal direction of the first-direction slit 31 and the direction in which the end portion 22 extends coincide with each other. Thereby, the overlap between the end portion 22 and the first-direction slit 31 can be confirmed more widely. Therefore, it is possible to realize the inductor 100 having higher connection reliability.

Hereinafter, another example of the peripheral configuration of the first-direction slit 31 will be described with reference to FIGS. 3 to 7. FIG. 3 is a perspective view showing a first alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 3 shows an inductor 100 having a first-way slit 31a in the same viewpoint as in FIG. 2B.

As shown in FIG. 3, the first-direction slit 31a is open on the plus side in the Z-axis direction. In other words, the elongated hole forming the first-direction slit 31a has an opening 31b that opens at the boundary between the side plate 36 and the outside in the Z-axis direction in a plan view seen from the Y-axis direction. It is integrated.

For example, if the bottom plate 34 side of the inductor 100 is arranged toward the lower side in the gravity direction and then the joining material 40 is supplied from the opening 31b, the joining material 40 flows toward the lower side in the gravity direction and naturally flows in the first direction. The slit 31a is filled. Further, the first-direction slit 31a is ring-opened. Therefore, it is possible to reduce the possibility that the joining material 40 does not flow into the positive side in the Y-axis direction by forming a film on the ring of the electrode member 30 due to surface tension and does not come into contact with the end portion 22. Therefore, the bonding material 40 can be supplied more easily, and the bonding between the end portion 22 and the electrode member 30 can be realized with higher reliability.

Further, FIG. 4 is a first perspective view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 4 shows an inductor 100 having a first-way slit 31 and a second-way slit 35 from the same viewpoint as in FIG. 2B.

As shown in FIG. 4, the second-direction slit 35 is composed of an elongated hole in the X-axis direction (second direction) that intersects the Z-axis direction, and the side plate 36 has a positive side and a negative side in the Y-axis direction. It communicates both main sides of. Further, the second direction slit 35 is integrated with the first direction slit 31, and the first direction slit 31 is arranged substantially at the center in the longitudinal direction of the second direction slit 35. By forming the second-direction slit 35, the opening on the negative side in the Y-axis direction becomes large, so that the bonding material 40 can be easily supplied.

For example, when the bottom plate 34 side of the inductor 100 is arranged toward the lower side in the gravity direction and then the joining material 40 is supplied, the joining material 40 flows toward the lower side in the gravity direction along the first direction slit 31. Here, when the supply amount of the joining material 40 is too large, the joining material 40 overflows to the main surface on the minus side in the Y-axis direction of the side plate 36 and flows out only by the first direction slit 31. When there is a second-direction slit 35, the joining material 40 that has reached the end on the negative side in the Z-axis direction of the first-direction slit 31 sequentially flows along the second-direction slit 35 to both sides in the X-axis direction. It is possible to prevent the joining material 40 from overflowing as described above. In the figure, an example of the inductor 100 provided with the two second-direction slits 35 is shown, but the number of the second-direction slits 35 is not particularly limited and may be one. It may be 3 or more. Further, the size of the second-direction slit 35 is not particularly limited, and the second-direction slit 35 having a shorter or longer length in the longitudinal direction or the lateral direction may be provided.

On the other hand, the case where the supply amount of the joining material 40 is too small will be described with reference to FIGS. 5 and 6. FIG. 5 is a second perspective view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. Further, FIG. 6 is a plan view showing a second alternative example of the peripheral configuration of the first-direction slit according to the embodiment. Note that FIG. 6A is a plan view of the inductor 100 viewed from the positive side in the Z-axis direction, and FIG. 6B is a plan view of the inductor 100 viewed from the negative side in the Y-axis direction. It is shown by connecting with.

As shown in FIG. 5, even when the supply amount of the joining material 40 is too small, between the inner side surface (the surface along the Y-axis direction) of the first-direction slit 31 and the second-direction slit 35 and the end portion 22. Since the wet surface is efficiently formed and the joining material 40 is distributed, a large area related to electrical contact between the electrode member 30 and the end portion 22 is maintained.

Further, as shown in FIGS. 5 and 6, the second-direction slit 35 is provided with a non-blocking region 35a that does not overlap with the end portion 22 in a plan view seen from the Y-axis direction. In the non-blocking region 35a, the internal space of the recess 32 can be accessed from the second-direction slit 35 regardless of the contact between the end portion 22 and the electrode member 30. Therefore, the joining material 40 that has reached the non-blocking region 35a also flows into the internal space of the recess 32. For example, as in the joining material 40 shown by the broken line in FIG. 6B, the joining material 40 that has flowed into the internal space joins the end portion 22 and the electrode member 30 even in the internal space of the recess 32. As a result, the connection reliability between the end portion 22 and the electrode member 30 is further improved.

FIG. 7 is a perspective view showing a third alternative example of the peripheral configuration of the first-direction slit according to the embodiment. FIG. 7 shows an inductor 100 having a first-direction slit 31a and a second-direction slit 35 from the same viewpoint as in FIG. 2B. As shown in FIG. 7, the features of the first and second examples described above can be combined without conflict. That is, the joining material 40 having the first-way slit 31a capable of supplying the joining material 40 from the opening 31b and satisfying the first-way slit 31a flows into the second-way slit 35, and also covers the non-blocking region 35a. An inductor 100 that flows into the internal space of the recess 32 via the recess 32 is realized.

In this case, the inductor 100 has a feature related to connection reliability between the end portion 22 and the electrode member 30 having a configuration that can be visually confirmed via the first-direction slit 31 described with reference to FIG. 2 above. Since the bonding material 40 can be easily supplied and the bonding material 40 is naturally expanded in a wide range and three-dimensionally in the XZ plane and in the Y-axis direction, it has high connection reliability.

The inductor 100 of the present embodiment may have a resin having adhesiveness interposed between the magnetic core 10 and the electrode member 30. Specifically, an adhesive resin is interposed between the side surface 12 of the magnetic core 10 and the first region 32a of the electrode member 30, and between the bottom surface 13 of the magnetic core 10 and the bottom plate 34 of the electrode member 30. You may. Preferable examples of the adhesive resin include thermosetting epoxy resin-based and silicone resin-based resins. According to this, in addition to the same effect as the above-mentioned effect, the physical connectivity between the magnetic core 10 and the electrode member 30 can be improved, so that the electrical and physical stability is higher and the connection reliability is higher. The inductor 100 can be realized.

[Production method]
Next, the manufacturing method of the above-mentioned inductor 100 will be described with reference to FIG. FIG. 8 is a flowchart showing a method of manufacturing an inductor according to an embodiment.

In the method for manufacturing the inductor 100, first, the magnetic core 10 is molded by pressure molding (step S101). The molding of the magnetic core 10 is carried out by pressure-molding the dust core 10 so as to include the coil element 20 in which the coil element 20 in which the embedded portion 21 is wound and the end portion 22 is extended by processing in advance. Will be done. After step S101, a step (step S102) of bending the end portion 22 exposed from the magnetic core 10 along the side surface 12 is performed. After that, the electrode member 30 is arranged so as to correspond to each of the two side surfaces 12 (step S103), and the alignment is performed.

At this time, the positions of the end portion 22 and the electrode member 30 are confirmed via the first-direction slit 31, and it is determined whether or not the positions of the electrode member 30 and the end portion 22 are normal (step S104). .. When it is determined that the positions of the electrode member 30 and the end portion 22 are not normal (No in step S104), the process returns to step S103, and the electrode member 30 is arranged again.

When it is determined that the positions of the electrode member 30 and the end portion 22 are normal (Yes in step S104), the joining material 40 is supplied into the first-way slit 31 to join the end portion 22 and the electrode member 30. (Step S105). As described above, since these joinings are performed in a state where the positions of the end portion 22 and the electrode member 30 are ensured to be normal, a more reliable inductor 100 is manufactured.

In the method for manufacturing the inductor 100 of the present embodiment, a step of interposing a resin having an uncured adhesive state between the magnetic core 10 and the electrode member 30 and a step of curing the adhesive resin are performed. It may be included. Specifically, the step of interposing the uncured adhesive resin between the magnetic core 10 and the electrode member 30 can be performed at the same time as the step of arranging the electrode member (step 103). Further, in the step of curing the adhesive resin, after the positions of the electrode member 30 and the end portion 22 are determined to be normal (Yes in step S104), the electrode member and the end portion are joined (step 105). ) Can be done before. According to this, in addition to the same effect as the above-mentioned effect, the physical connectivity between the magnetic core 10 and the electrode member 30 can be improved, so that the electrical and physical stability is higher and the connection reliability is higher. The inductor 100 can be realized.

[Effects, etc.]
As described above, the inductor 100 according to the present embodiment includes a three-dimensional magnetic core 10 containing a magnetic material and having a side surface 12, a buried portion 21 containing a metal material and embedded in the magnetic core 10, and a magnetic core. A coil element 20 having an end portion 22 exposed from 10 and an electrode member 30 containing a metal material and arranged on the opposite side of the magnetic core 10 with the end portion 22 of the coil element 20 interposed therebetween, and an end portion of the coil element 20. 22 and a conductive bonding material 40 for joining the electrode member 30 are provided, and the electrode member 30 is a side plate 36 arranged along the side surface 12 of the magnetic core 10 in a first direction along the side surface 12. The side plate 36 is provided with a first-direction slit 31 formed of an elongated hole that communicates both main surfaces of the side plate 36 in an elongated shape, and the end portion 22 of the coil element 20 has a side surface 12 along the first direction. It extends upward and overlaps the first-direction slit 31 in the communication direction of both main surfaces, and the bonding material 40 is arranged inside the first-direction slit 31.

In such an inductor 100, it can be determined whether or not the positions of the electrode member 30 and the end portion 22 of the coil element 20 are normal via the first-direction slit 31. The position of the electrode member 30 and the end portion 22 can be determined both before and after the supply of the joining material 40. For example, by determining the position of the electrode member 30 and the end portion 22 before supplying the joining material 40, it is possible to improve the accuracy of joining the electrode member 30 and the end portion 22 by the joining material 40. Further, for example, by being able to determine the position of the electrode member 30 and the end portion 22 after supplying the joining material 40, it can be confirmed that the joining of the electrode member 30 and the end portion 22 by the joining material 40 is normally completed. You can check it. In this way, the first-direction slit 31 makes it possible to confirm that the accuracy of the joining is improved before and after the joining.

Further, a wet surface of the joining material 40 is formed at a boundary portion between the inner surface of the first-direction slit 31 and the main surface of the end portion 22 on the electrode member 30 side. For example, the electrode member 30 and the end portion 22 are joined on the wet surface even if a sufficient amount of the joining material 40 is not supplied to fill the first-direction slit 31. As described above, even a small amount of the joining material 40 can sufficiently join the electrode member 30 and the end portion 22. That is, the electrode member 30 and the end portion 22 are stably joined regardless of the variation in the supply amount of the joining material 40. Due to these effects, the electrode member 30 and the end portion 22 are accurately and stably joined and electrically connected, so that the inductor 100 having higher connection reliability is realized.

Further, for example, the three-dimensional shape of the magnetic core 10 has a bottom surface 13 that intersects the side surface 12, and the electrode member 30 is a bottom plate 34 arranged along the bottom surface 13, and the bottom plate 34 connected to the side plate 36. You may have.

According to this, the magnetic core 10 and the electrode member 30 come into contact with each other at the bottom surface 13 intersecting the side surface 12 and the side surface 12. Since the magnetic core 10 and the electrode member 30 are in three-dimensional contact with each other, changes in the positional relationship such as wobbling are less likely to occur. Therefore, since the positional relationship between the coil element 20 and the electrode member 30 fixed by being partially embedded in the magnetic core 10 is less likely to change, the connection stability between the coil element 20 and the electrode member 30 is improved. To. Further, the contact area in contact with the land on the circuit board on which the inductor 100 is mounted can be expanded. Therefore, the inductor 100 having higher connection reliability is realized.

Further, for example, the side plate 36 has a first region 32a facing the side surface 12 of the magnetic core 10 and a second region 32b facing the end portion 22 of the coil element 20 in the plan view of the side plate 36. The first region 32a and the second region 32b are recesses 32 in which the second region 32b is concave in the direction away from the side surface 12 of the magnetic core 10 with respect to the first region 32a, and the coil is formed in the recess 32. A recess 32 for accommodating the end 22 of the element 20 is formed, and the first-way slit 31 may be formed at the bottom of the recess 32.

According to this, even if the end portion 22 is housed in the internal space formed by the recess 32 and the electrode member 30 overlaps the end portion 22 protruding outward from the magnetic core 10, the first region 32a In, the magnetic core 10 and the electrode member 30 can come into contact with each other without passing through the end portion 22 of the coil element 20. Therefore, a dead spaceless and compact inductor 100 can be realized. Further, since the magnetic core 10 and the electrode member 30 can come into contact with each other without passing through the end portion 22 of the coil element 20, changes in the positional relationship such as wobbling of the electrode member 30 with respect to the magnetic core 10 are less likely to occur. Therefore, since the positional relationship between the coil element 20 and the electrode member 30 fixed by being partially embedded in the magnetic core 10 is less likely to change, the connection stability between the coil element 20 and the electrode member 30 is improved. To. It should be noted that the same effect as described above can be obtained by forming the recess 32 for accommodating the end portion 22 on the side surface 12 of the magnetic core 10.

Further, for example, the elongated hole forming the first-direction slit 31 may be opened at the boundary portion of the side plate 36 in the plan view of the side plate 36.

According to this, the joining material 40 can be supplied into the first-direction slit 31a from the opening 31b formed by the opening. By facilitating the supply of the joining material 40, it is possible to reduce the supply error of the joining material 40. That is, since it is possible to reduce the inductors having poor connection caused by the supply error of the joining material 40, it is possible to realize the inductor 100 having higher connection reliability.

Further, for example, the side plate 36 has a long hole that communicates both main surfaces of the side plate 36 in a long shape in the second direction intersecting the first direction, and is integrated with the first direction 31 slit. At least one bidirectional slit 35 may be provided, and the joining material 40 may be arranged inside the first direction slit 31 and the second direction slit 35.

According to this, a wet surface of the joining material 40 is formed at the boundary portion between the inner side surface of the first direction slit 31 and the second direction slit 35 and the main surface of the end portion 22 on the electrode member 30 side. For example, the electrode member 30 and the end portion 22 are joined on the above-mentioned wet surface even if a sufficient amount of the joining material 40 is not supplied to satisfy the first-way slit 31 and the second-way slit 35. As described above, even a small amount of the joining material 40 can sufficiently join the electrode member 30 and the end portion 22. Further, even when a larger amount of the joining material 40 is supplied than filling the first direction slit 31, the joining material 40 flows into the second direction slit 35, so that the joining material 40 is sent from the first direction slit 31 and the second direction slit 35. It is possible to suppress a connection failure due to the overflow of 40. In this way, the electrode member 30 and the end portion 22 are stably joined regardless of the variation in the supply amount of the joining material 40. Therefore, the inductor 100 having higher connection reliability is realized.

Further, for example, at least a part of the second-direction slit 35 may have a non-occluded region 35a that does not overlap with the end portion 22 of the coil element 20.

According to this, since the second-direction slit 35 and the internal space of the recess 32 are connected to each other via the non-occluded region 35a, the joining material 40 also flows into the internal space side. Therefore, in the portion of the end portion 22 that intersects the surface facing the side plate 36, a wet surface of the bonding material 40 is formed at the boundary portion of the side plate 36 with the main surface on the internal space side, and the electrode is formed on this wet surface. The member 30 and the end portion 22 are joined. Therefore, since the electrode member 30 and the end portion 22 are joined over a wider area only by supplying the joining material 40 from the first-way slit 31, the inductor 100 having higher connection reliability is easily realized.

Further, for example, the three-dimensional shape of the magnetic core 10 has a top surface 14 that intersects the side surface 12, and on the intersection line where the top surface 14 and the side surface 12 intersect, the top surface 14 and the side surface 12 are inside the magnetic core 10. Even if the electrode member 30 has a locking portion 33 that protrudes from the side plate 36 in the direction along the top surface 14 and is locked to the notch portion 15 by providing a notch portion 15 that is concave toward the surface. good.

According to this, the locking portion 33 is locked to the notch portion 15, so that the relative movement of the electrode member 30 with respect to the magnetic core 10 is suppressed. Since the relative position between the magnetic core 10 and the electrode member 30 is stabilized before the joining material 40 is supplied, the joining material 40 can be joined in a more appropriate positional relationship. Further, even after the joining material 40 is supplied, changes in the positional relationship such as wobbling of the electrode member 30 are less likely to occur with respect to the magnetic core 10. That is, since the positional relationship between the coil element 20 fixed to the electrode member 30 and the electrode member 30 is less likely to change by being partially embedded in the magnetic core 10, the connection stability between the coil element 20 and the electrode member 30 is improved. To.

Further, as compared with the configuration in which the protrusion protruding from the electrode member 30 is inserted into the recessed portion provided in the middle of the magnetic core 10 to obtain the same effect, the region for blocking the magnetic flux in the magnetic core 10 is reduced, so that the magnetic characteristics are reduced. It is excellent in that it can suppress the deterioration of the magnetic flux. Further, since the locking portion 33 suppresses the magnetic core 10 from falling off from the circuit board on which the inductor 100 is mounted toward the plus side in the Z-axis direction, the seismic performance of the inductor 100 during use after mounting is improved. Also contributes to.

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

For example, an electric product or an electric circuit using the above-mentioned inductor is also included in the present disclosure. Examples of the electric product include a power supply device provided with the above-mentioned inductor, various devices provided with the power supply device, and the like.

Further, the present disclosure is not limited to this embodiment. As long as it does not deviate from the gist of the present disclosure, various modifications that can be conceived by those skilled in the art are applied to this embodiment, and a form constructed by combining components in different embodiments is also within the scope of one or more embodiments. May be included within.

The inductor according to the present disclosure is useful as an inductor used in various devices and devices.

10, 10x magnetic core 11, 12 side surface 13 bottom surface 14 top surface 15 notch part 20, 20x coil element 21, 21x embedded part 22, 22x end part 30, 30x electrode member 31, 31a first direction slit 31b opening 32 recess 32a First area 32b Second area 33 Locking part 34 Bottom plate 35 Second direction slit 35a Non-blocking area 36 Side plate 40 Joining material 100, 100x Inductor

Claims (7)

A three-dimensional magnetic core that contains magnetic materials and has sides,
A coil element containing a metal material and having an embedded portion embedded in the magnetic core and an end exposed from the magnetic core.
An electrode member containing a metal material and arranged on the side opposite to the magnetic core with the end of the coil element interposed therebetween.
A conductive joining material for joining the end portion of the coil element and the electrode member is provided.
The electrode member is a side plate arranged along the side surface of the magnetic core, and is a first direction composed of elongated holes communicating with both main surfaces of the side plate in a long shape in the first direction along the side surface. It has a side plate with a slit and
The end portion of the coil element extends on the side surface along the first direction and overlaps the first direction slit in the communication direction of both main surfaces.
The joining material is arranged inside the first direction slit.
Inductor. The three-dimensional shape of the magnetic core has a bottom surface that intersects the side surface and has a bottom surface.
The electrode member is a bottom plate arranged along the bottom surface and has a bottom plate connected to the side plate.
The inductor according to claim 1. The side plate has a first region facing the side surface of the magnetic core and a second region facing the end portion of the coil element in a plan view of the side plate.
The first region and the second region are recesses in which the second region is concave in a direction away from the side surface of the magnetic core with respect to the first region, and the coil element is formed in the recess. It forms a recess to accommodate the end of the
The first-way slit is formed in the bottom of the recess.
The inductor according to claim 1 or 2. The elongated hole forming the first-direction slit opens at the boundary portion of the side plate in a plan view of the side plate.
The inductor according to any one of claims 1 to 3. The side plate is composed of an elongated hole that communicates both main surfaces of the side plate in a long shape in a second direction intersecting the first direction, and is integrated with the first direction slit. Is provided at least one
The joining material is arranged inside the first-way slit and the second-way slit.
The inductor according to any one of claims 1 to 4. At least a portion of the second direction slit has a non-occluded region that does not overlap with the end of the coil element.
The inductor according to claim 5. The three-dimensional shape of the magnetic core has a top surface that intersects the side surface, and has a top surface.
On the intersection line where the top surface and the side surface intersect, a notch portion that is concave from the top surface and the side surface toward the inside of the magnetic core is provided.
The electrode member has a locking portion that protrudes from the side plate toward the top surface and is locked to the notch portion.
The inductor according to any one of claims 1 to 6.

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