JP4547889B2 - Magnetic coupling element - Google Patents

Description

  The present invention relates to a magnetic coupling element.

In recent years, the driving frequency of switching power supplies has been increased more and more due to advances in semiconductor switching elements such as FETs and advances in circuit technology such as soft switching. When the drive frequency is increased in this way, the inductance value required for the transformer, choke coil, etc. can be reduced. For this reason, an inductor having a structure in which a linear conductor (metal conductor) is sandwiched between upper and lower magnetic bodies can be used (for example, see Patent Document 1).
JP 2000-323336 A

  An object of the present invention is to provide a magnetic coupling element having a high coupling coefficient of a conductor and a small leakage inductance.

  The present inventors paid attention to a configuration in which a plurality of conductors are overlapped and surrounded by a magnetic body as a magnetic coupling element having a configuration in which the coupling coefficient of the conductor is high and the leakage inductance can be reduced. As a result of extensive research, the following facts were newly found.

When the magnetic coupling element has a configuration in which a plurality of conductors are overlapped and surrounded by a magnetic material, that is, a configuration in which a plurality of metal conductors are magnetically coupled, the effect of leakage inductance becomes relatively large as the inductance value decreases. For this reason, there is a problem that the coupling coefficient K shown in the following equation (1) is reduced, and the transmission efficiency is lowered.
K = M / (L ₁ · L ₂ ) ^1/2 (1)
Here, M is a mutual inductance value, and L ₁ and L ₂ are self-inductance values of the corresponding conductors (coils).

  Further, when the magnetic coupling element is used in combination with a switching element such as a converter for a switching power supply, the following problems occur. When the leakage inductance of the magnetic coupling element is large, the surge voltage generated in the switching element due to the energy due to the leakage inductance increases. For this reason, it becomes necessary to use a high withstand voltage switching element or to provide a circuit for absorbing the surge voltage separately.

  In view of such research results, the magnetic coupling element according to the present invention has a plate-like shape, and the first conductor and the second conductor, and the first conductor and the second conductor, which are stacked in an electrically insulated state. And a magnetic body disposed so as to surround the two conductors, wherein the first conductor has terminals that lead out at least one each from two different surfaces of the magnetic body, and the second conductor The conductor has terminals that are led out to at least one each from two different surfaces of the magnetic material from which the terminal of the first conductor is derived, and at least a part of the surface of the magnetic material from which the terminal is derived Is separated from the gap region between the terminals of the first conductor and the second conductor.

  In the magnetic coupling element according to the present invention, since the first conductor and the second conductor are stacked in an electrically insulated state, the magnetism between the first conductor and the second conductor. The bond is good.

  By the way, when a current flows through each terminal of each conductor, a strong magnetic field is generated between the terminals of the first conductor and the second conductor derived from the same surface of the magnetic body. If a medium having a large relative permeability such as a magnetic material is present in the vicinity of a gap region between terminals where a strong magnetic field is generated, the magnetic flux density in the region where the medium is present increases. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals increases, and the leakage inductance increases.

  However, in the present invention, since at least a part of the surface of the magnetic body from which the terminal is derived is separated from the gap region between the terminals of the first conductor and the second conductor, a strong magnetic field is generated between the terminals. Even if it occurs, the magnetic flux density near the gap region between the terminals does not increase. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals is reduced, and the leakage inductance is reduced.

  From the above, it is possible to increase the coupling coefficient between the first conductor and the second conductor and reduce the leakage inductance.

  Further, it is preferable that a portion corresponding to the gap region between the terminals on the surface of the magnetic body from which the terminal is derived is cut away so as to be separated from the gap region between the terminals. When configured in this manner, the portion corresponding to the gap region between the terminals on the surface of the magnetic body from which the terminals are derived can be reliably separated from the gap region between the terminals with an extremely simple configuration. In addition, the decrease in the effective cross-sectional area of the magnetic material can be suppressed to a low level, and it is possible to suppress the inductance value from decreasing and to suppress the magnetic flux density from increasing.

  Further, it is preferable that a step is formed on the surface of the magnetic body from which the terminal is derived, and the side lowered by the step is separated from the gap region between the terminals. When configured in this manner, the portion corresponding to the gap region between the terminals on the surface of the magnetic body from which the terminals are derived can be reliably separated from the gap region between the terminals with an extremely simple configuration.

  The terminals of the first conductor and the second conductor are preferably bent in the same direction. When configured in this manner, surface mounting on an external substrate can be easily performed.

  Further, it is preferable that a portion corresponding to the gap region between the terminals on the side where the terminals are bent on the surface of the magnetic body from which the terminals are led out is cut away from the gap region between the terminals. When configured in this way, the portion corresponding to the gap region between the terminals on the side where the terminals are bent on the surface of the magnetic body from which the terminals are derived can be reliably secured from the gap region between the terminals with an extremely simple configuration. Can be released. In addition, the decrease in the effective cross-sectional area of the magnetic material can be suppressed to a low level, and it is possible to suppress the inductance value from decreasing and to suppress the magnetic flux density from increasing.

  Further, a step is formed on the surface of the magnetic body from which the terminal is led out so that the side on which the terminal of the surface is bent is lowered, and the side on which the terminal is bent on the surface of the magnetic body from which the terminal is led by the step. It is preferable to be away from the gap region between the terminals. When configured in this way, the portion corresponding to the gap region between the terminals on the side where the terminals are bent on the surface of the magnetic body from which the terminals are derived can be reliably secured from the gap region between the terminals with an extremely simple configuration. Can be released.

  Moreover, it is preferable that the surface of the magnetic body from which the terminal is led out is separated from the gap region between the terminals by protruding from the magnetic body in a state where the first conductor and the second conductor are overlapped. When configured in this manner, the portion corresponding to the gap region between the terminals on the surface of the magnetic body from which the terminals are derived can be reliably separated from the gap region between the terminals with an extremely simple configuration.

  In addition, the number of terminals of the first conductor and the second conductor derived from the same surface of the magnetic body is plural for at least one of the conductors, and the first conductor derived from the same surface of the magnetic body. It is preferable that the terminals of the second conductor and the terminals of the second conductor are alternately arranged adjacent to each other. In such a configuration, there are a plurality of gap regions between the terminals of the first conductor and the second conductor, and the sum of the energy concentrated in each gap region is the energy of the case where there is one gap region. It decreases to the reciprocal times the number of gap regions. As a result, the leakage inductance can be further reduced.

  According to the present invention, a magnetic coupling element having a high coupling coefficient and a small leakage inductance can be provided.

  A magnetic coupling element according to an embodiment of the present invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

(First embodiment)
1 is an overall perspective view showing the magnetic coupling element according to the first embodiment, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a magnetic coupling element according to the first embodiment. FIG. In the description, the terms “upper” and “lower” may be used, which correspond to the vertical direction in FIG.

  As shown in FIGS. 1 to 3, the magnetic coupling element MC <b> 1 includes a first conductor 1, a second conductor 11, and a magnetic body 21.

  The first conductor 1 has a plate-like base portion 3 that has a rectangular shape, and terminals 5 that extend from two opposing sides of the base portion 3. The width of the terminal 5 (length in the left-right direction in FIG. 1) is set to a value (less than half the width of the base 3) that is narrower than the width of the base 3 (length in the left-right direction in FIG. 1). ing. The first conductor 1 is made of a highly conductive metal (for example, copper, aluminum, etc.).

  The second conductor 11 has a plate-like base 13 having a rectangular shape and terminals 15 extending from two opposing sides of the base 13. The width of the terminal 15 (length in the left-right direction in FIG. 1) is set to a value (less than half the width of the base 13) that is narrower than the width of the base 13 (length in the left-right direction in FIG. 1). ing. Similar to the first conductor 1, the second conductor 11 is made of a highly conductive metal (eg, copper, aluminum, etc.).

  The first conductor 1 and the second conductor 11 are overlapped in an electrically insulated state by the base 3 and the base 13 being overlapped with each other via the electrical insulating material 31.

  Instead of using the electrical insulating material 31, an electrical insulating material may be applied in layers to at least one of the base 3 and the base 13. In this case, you may apply | coat to the whole bases 3 and 13, and you may make it apply | coat only to the opposing surface of the bases 3 and 13. FIG.

  The magnetic body 21 has a substantially rectangular parallelepiped shape, and has a cylindrical shape by forming a hollow portion. The magnetic body 21 includes an upper magnetic body 23 having a U-shaped core shape and a lower magnetic body 25 having a I-shaped core shape. The upper magnetic body 23 and the lower magnetic body 25 are integrated by bonding or the like. The hollow portion is defined by the upper magnetic body 23 and the lower magnetic body 25. For the upper magnetic body 23 and the lower magnetic body 25, a compacted body of metal magnetic powder, a metal magnetic body whose surface is insulated, ferrite, or the like can be used. For bonding the upper magnetic body 23 and the lower magnetic body 25, paste-like composite ferrite prepared by mixing ferrite powder into a resin material such as epoxy resin can be used. Further, the inductance may be adjusted by inserting a gap material such as a plastic film between the bonding surfaces of the upper magnetic body 23 and the lower magnetic body 25.

  The magnetic body 21 is disposed so as to surround the first conductor 1 and the second conductor 11, and the first conductor 1 and the second conductor 11 pass through the hollow portion of the magnetic body 21. Yes. The base portions 3 and 13 of the first conductor 1 and the second conductor 11 stacked in an electrically insulated state are located in the hollow portion of the magnetic body 21. The terminals 5 and 15 of the first conductor 1 and the second conductor 11 are located outside the magnetic body 21.

  The terminals 5 of the first conductor 1 are led out from two different surfaces of the magnetic material 21 (in the present embodiment, two surfaces facing each other). The terminals 15 of the second conductor 11 are also led out from the two different surfaces of the magnetic body 21 from which the terminal 5 of the first conductor 1 is led. The terminal 5 of the first conductor 1 and the terminal 15 of the second conductor 11 are led out from the same surface of the magnetic body 21 in an adjacent state.

  The terminals 5 and 15 of the first conductor 1 and the second conductor 11 are bent in the same direction (downward in the present embodiment) so as to be along the derived surface. Further, the tip portions of the terminals 5 and 15 are bent along the lower surface of the lower magnetic body 25. The tip portions of the terminals 5 and 15 are respectively placed on land portions of an external substrate (not shown) and soldered to the land portions.

  A portion of the surface of the magnetic body 21 (lower magnetic body 25) corresponding to the gap region between the terminals 5 and 15 on the surface from which the terminals 5 and 15 are led is notched away from the gap region between the terminals 5 and 15. As a result, a recess 25a is formed. As a result, a part of the surface of the lower magnetic body 25 from which the terminals 5 and 15 are led out from the gap region between the terminals 5 and 15. The depth of the recess 25a is preferably equal to or greater than the width of the gap between the terminals 5 and 15. The width of the recess 25 a is preferably larger than the width of the gap between the terminals 5 and 15.

  As described above, in the first embodiment, the base portion 3 of the first conductor 1 and the base portion 13 of the second conductor 11 are overlapped in an electrically insulated state. The magnetic coupling between the conductor 1 and the second conductor 11 becomes good.

  By the way, when a current flows through the respective terminals 5 and 15 of the respective conductors 1 and 11, the first conductor 1 and the terminals 5 and 15 of the second conductor 11 derived from the same surface of the magnetic body 21 are used. A strong magnetic field is generated between them. If a medium having a large relative permeability such as a magnetic material is present in the vicinity of the gap region between the terminals 5 and 15 where a strong magnetic field is generated, the magnetic flux density in the region where the medium is present increases. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 5 and 15 increases, and the leakage inductance increases.

  However, in the first embodiment, a part of the surface from which the terminals 5 and 15 are derived in the magnetic body 21 (lower magnetic body 25) from which the terminals 5 and 15 are derived is the first conductor 1 and the second conductor 21. Since the conductor 11 is separated from the gap region between the terminals 5 and 15, even if a strong magnetic field is generated between the terminals 5 and 15, the magnetic flux density in the vicinity of the gap region between the terminals 5 and 15 is increased. There is nothing wrong. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 5 and 15 is reduced, and the leakage inductance is reduced.

  From the above, it is possible to increase the coupling coefficient between the first conductor 1 and the second conductor 11 and reduce the leakage inductance.

  In the first embodiment, the terminals 5 and 15 of the first conductor 1 and the second conductor 11 are bent in the same direction. Thereby, the surface mounting to an external board | substrate can be performed easily.

  Further, in the first embodiment, in the gap region between the terminals 5 and 15 on the side where the terminals 5 and 15 are bent on the surface from which the terminals 5 and 15 of the magnetic body 21 (lower magnetic body 25) are led out. Corresponding portions are cut away from the gap region between the terminals 5 and 15. Thus, the portion corresponding to the gap region between the terminals 5 and 15 on the surface of the magnetic body 21 from which the terminals 5 and 15 are derived is reliably separated from the gap region between the terminals 5 and 15 with an extremely simple configuration. be able to. In addition, the decrease in the effective cross-sectional area of the magnetic body 21 can be suppressed low, the inductance value can be suppressed from decreasing, and the magnetic flux density can be suppressed from increasing.

  In the first embodiment, since the first conductor 1 and the second conductor 11 (base portions 3 and 13) are wide and extend in a flat plate shape, the electrical resistance value is extremely low. A large current can flow. Thereby, the magnetic coupling element MC1 can meet the demand for a low voltage and large current.

(Second Embodiment)
4 is an overall perspective view showing the magnetic coupling element according to the second embodiment, FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4, and FIG. 6 is a magnetic coupling element according to the second embodiment. FIG. In the description, the terms “upper” and “lower” may be used, which correspond to the vertical direction in FIG.

  The magnetic coupling element MC2 includes the first conductor 1, the second conductor 11, and the magnetic body 41, as shown in FIGS.

  The magnetic body 41 has a substantially rectangular parallelepiped shape, and has a cylindrical shape by forming a hollow portion. The magnetic body 41 includes an upper magnetic body 43 having a U-shaped core shape and a lower magnetic body 45 having a I-shaped core shape. The upper magnetic body 43 and the lower magnetic body 45 are integrated by bonding or the like. The hollow portion is defined by the upper magnetic body 43 and the lower magnetic body 45. For the upper magnetic body 43 and the lower magnetic body 45, a compacted body of metal magnetic powder, a metal magnetic body whose surface is insulated, ferrite, or the like can be used. For bonding the upper magnetic body 43 and the lower magnetic body 45, a paste-like composite ferrite prepared by mixing a ferrite powder with a resin material such as an epoxy resin can be used. Further, the inductance may be adjusted by inserting a gap material such as a plastic film between the bonding surfaces of the upper magnetic body 43 and the lower magnetic body 45.

  The magnetic body 41 is disposed so as to surround the first conductor 1 and the second conductor 11, and the first conductor 1 and the second conductor 11 pass through the hollow portion of the magnetic body 41. Yes. Both ends of the base portions 3 and 13 of the first conductor 1 and the second conductor 11 stacked in an electrically insulated state protrude from the magnetic body 41. As a result, the surfaces of the magnetic body 41 (the upper magnetic body 43 and the lower magnetic body 45) from which the terminals 5 and 15 are led away from the gap region between the terminals 5 and 15. In addition, it is preferable that the protrusion amount of the bases 3 and 13 of the first conductor 1 and the second conductor 11 is equal to or greater than the value of the width of the gap between the terminals 5 and 15.

  Each of the terminals 5 of the first conductor 1 is led out from two different surfaces of the magnetic body 41. The terminals 15 of the second conductor 11 are also led out from the two different surfaces of the magnetic body 41 from which the terminal 5 of the first conductor 1 is derived. The terminal 5 of the first conductor 1 and the terminal 15 of the second conductor 11 are led out from the same surface of the magnetic body 41 in an adjacent state. The terminals 5 and 15 of the first conductor 1 and the second conductor 11 are bent in the same direction (in the present embodiment, downward) substantially parallel to the derived surface of the lower magnetic body 45. Yes. Further, the tip portions of the terminals 5 and 15 are bent along the lower surface of the lower magnetic body 45.

  As described above, in the second embodiment, the surface of the magnetic body 41 from which the terminals 5 and 15 are derived is the surface from which the terminals 5 and 15 are derived is the terminal 5 of the first conductor 1 and the second conductor 11. , 15 is separated from the gap region between the terminals 5 and 15, even if a strong magnetic field is generated between the terminals 5 and 15, the magnetic flux density in the vicinity of the gap region between the terminals 5 and 15 does not increase. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 5 and 15 is reduced, and the leakage inductance is reduced.

  Therefore, also in the second embodiment, it is possible to increase the coupling coefficient between the first conductor 1 and the second conductor 11 and reduce the leakage inductance.

  In the second embodiment, the first conductor 1 and the second conductor 11 protrude from the magnetic body 41 in a state where the first conductor 1 and the second conductor 11 are overlapped with each other, so that the terminals 5 and 15 are led out. 41 faces away from the gap region between the terminals 5 and 15. Thus, with a very simple configuration, the portion corresponding to the gap region between the terminals 5 and 15 on the surface of the magnetic body 41 from which the terminals 5 and 15 are derived is reliably separated from the gap region between the terminals 5 and 15. be able to.

  In the second embodiment, the magnetic coupling element MC2 can meet the demand for a low voltage and a large current, like the magnetic coupling element MC1 of the first embodiment.

(Third embodiment)
7 is an overall perspective view showing the magnetic coupling element according to the third embodiment, FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7, and FIG. 9 is a magnetic coupling element according to the third embodiment. FIG. In the description, the terms “upper” and “lower” may be used, which correspond to the vertical direction in FIG.

  The magnetic coupling element MC3 includes the first conductor 1, the second conductor 11, and the magnetic body 51, as shown in FIGS.

  The magnetic body 51 has a cylindrical shape by forming a hollow portion. The magnetic body 51 includes an upper magnetic body 53 having a U-shaped core shape and a lower magnetic body 55 having a I-shaped core shape. The upper magnetic body 53 and the lower magnetic body 55 are integrated by bonding or the like. The hollow portion is defined by the upper magnetic body 53 and the lower magnetic body 55. As the upper magnetic body 53 and the lower magnetic body 55, a compacted body of metal magnetic powder, a metal magnetic body whose surface is insulated, ferrite, or the like can be used. For bonding the upper magnetic body 53 and the lower magnetic body 55, a paste-like composite ferrite prepared by mixing a ferrite powder with a resin material such as an epoxy resin can be used. Further, the inductance may be adjusted by inserting a gap material such as a plastic film between the bonding surfaces of the upper magnetic body 53 and the lower magnetic body 55.

  The length of the lower magnetic body 55 in the direction in which the hollow portion of the magnetic body 51 extends (depth direction: right and left direction in FIG. 8) is larger than the length of the upper magnetic body 53 in the direction in which the hollow portion of the magnetic body 51 extends. Steps are formed on two surfaces that are set short and are orthogonal to the direction in which the hollow portion of the magnetic body 51 extends.

  The magnetic body 51 is disposed so as to surround the first conductor 1 and the second conductor 11, and the first conductor 1 and the second conductor 11 pass through the hollow portion of the magnetic body 21. Yes. The base portions 3 and 13 of the first conductor 1 and the second conductor 11 stacked in an electrically insulated state are located in the hollow portion. The terminals 5 and 15 of the first conductor 1 and the second conductor 11 are located outside the magnetic body 51. Since the step is formed in the magnetic body 51, a part of the base portion 13 of the second conductor 11 located on the lower side is exposed.

  Each of the terminals 5 of the first conductor 1 is led out from two surfaces orthogonal to the direction in which the hollow portion of the magnetic body 51 extends. The terminals 15 of the second conductor 11 are also led out from the two surfaces perpendicular to the direction in which the hollow portion extends in the magnetic body 51 from which the terminal 5 of the first conductor 1 is led out. The terminal 5 of the first conductor 1 and the terminal 15 of the second conductor 11 are led out from the same surface of the magnetic body 51 in an adjacent state.

  The terminals 5 and 15 of the first conductor 1 and the second conductor 11 are bent substantially in parallel to the side surface of the lower magnetic body 55 and in the same direction (downward in this embodiment). The tip portions of the terminals 5 and 15 are bent along the lower surface of the lower magnetic body 55.

  In the magnetic coupling element MC3, due to the above-described configuration, a step is formed on the surface of the magnetic body 51 from which the terminals 5 and 15 are led out such that the side on which the terminals 5 and 15 are bent is lowered. The side where the terminals 5 and 15 are bent on the surface of the magnetic body 51 from which the terminals 5 and 15 are derived is separated from the gap region between the terminals 5 and 15. The height of the step is preferably equal to or greater than the width of the gap between the terminals 5 and 15.

  As described above, in the third embodiment, a part of the surface from which the terminals 5 and 15 are derived in the magnetic body 51 from which the terminals 5 and 15 are derived is part of the first conductor 1 and the second conductor 11. Since it is separated from the gap region between the terminals 5 and 15, even if a strong magnetic field is generated between the terminals 5 and 15, the magnetic flux density in the vicinity of the gap region between the terminals 5 and 15 does not increase. . As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 5 and 15 is reduced, and the leakage inductance is reduced.

  Therefore, also in the third embodiment, the coupling coefficient between the first conductor 1 and the second conductor 11 can be increased to reduce the leakage inductance.

  Further, in the third embodiment, a step is formed on the surface of the magnetic body 51 from which the terminals 5 and 15 are led out so that the side on which the terminals 5 and 15 are bent is lowered. The side where the terminals 5, 15 are bent on the surface of the magnetic body 51 from which 5, 15 is led (the side surface perpendicular to the direction in which the hollow portion of the lower magnetic body 55 extends) is separated from the gap region between the terminals 5, 15. ing. Thereby, with a very simple configuration, a portion corresponding to the gap region between the terminals 5 and 15 on the side where the terminals 5 and 15 are bent on the surface of the magnetic body 51 from which the terminals 5 and 15 are led out is represented by the terminal 5. , 15 can be reliably separated from the gap region.

  In the third embodiment, the magnetic coupling element MC3 can meet the demand for a low voltage and a large current, like the magnetic coupling element MC1 of the first embodiment.

(Fourth embodiment)
FIG. 10 is an overall perspective view showing the magnetic coupling element according to the fourth embodiment, and FIG. 11 is an exploded perspective view showing the magnetic coupling element according to the fourth embodiment. In the description, the terms “upper” and “lower” are sometimes used, which correspond to the vertical direction of FIG.

  As shown in FIGS. 10 and 11, the magnetic coupling element MC <b> 4 includes a first conductor 61, a second conductor 71, and a magnetic body 21.

  The first electric conductor 61 has a plate-like base portion 3 having a rectangular shape, and a terminal 65 that extends one by one from the central portions of the two opposite sides of the base portion 3. The first conductor 61 is made of a highly conductive metal (for example, copper, aluminum, etc.).

  The second conductor 71 has a plate-like and rectangular base 13 and a plurality of terminals 75 (two in the present embodiment) extending from end portions of the two opposite sides of the base 13. have. Similar to the first conductor 61, the second conductor 71 is made of a highly conductive metal (eg, copper, aluminum, etc.).

  The first conductor 61 and the second conductor 71 are overlapped in an electrically insulated state by the base 3 and the base 13 being overlapped with each other via the electrical insulating material 31.

  Each of the terminals 65 of the first conductor 61 is led out from two different surfaces of the magnetic body 21. The terminals 75 of the second conductor 71 are also led out from the two different surfaces of the magnetic body 21 from which the terminal 65 of the first conductor 61 is led. The terminal 65 of the first conductor 61 and the terminal 75 of the second conductor 71 are led out from the same surface of the magnetic body 21 in a state of being alternately adjacent to each other.

  The terminals 65 and 75 of the first conductor 61 and the second conductor 71 are bent in the same direction (downward in the present embodiment) so as to be along the derived surface. Further, the tip portions of the terminals 65 and 75 are bent along the lower surface of the lower magnetic body 25. The tip portions of the terminals 65 and 75 are respectively placed on land portions of an external substrate (not shown) and soldered to the land portions.

  A portion of the surface of the magnetic body 21 (lower magnetic body 25) corresponding to the gap region between the terminals 65 and 75 on the surface from which the terminals 65 and 75 are led is notched away from the gap region between the terminals 65 and 75. As a result, a recess 25a is formed. Accordingly, a part of the surface of the lower magnetic body 25 from which the terminals 65 and 75 are led out from the gap region between the terminals 65 and 75. Note that the depth of the recess 25a is preferably equal to or greater than the value of the width of the gap between the terminals 65 and 75.

  As described above, in the fourth embodiment, the base 63 of the first conductor 61 and the base 73 of the second conductor 71 are overlapped in an electrically insulated state. The magnetic coupling between the conductor 61 and the second conductor 71 is improved.

  In the fourth embodiment, a part of the surface of the magnetic body 21 (lower magnetic body 25) from which the terminals 65 and 75 are led out from which the terminals 65 and 75 are led out is the first conductor 61 and the second conductor 61. Since the conductor 71 is separated from the gap region between the terminals 65 and 75, even if a strong magnetic field is generated between the terminals 65 and 75, the magnetic flux density in the vicinity of the gap region between the terminals 65 and 75 is increased. There is nothing wrong. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 65 and 75 is reduced, and the leakage inductance is reduced.

  From the above, it is possible to increase the coupling coefficient between the first conductor 61 and the second conductor 71 and reduce the leakage inductance.

  In the fourth embodiment, the terminals 65 and 75 of the first conductor 61 and the second conductor 71 are bent in the same direction. Thereby, the surface mounting to an external board | substrate can be performed easily.

  In the fourth embodiment, in the gap region between the terminals 65 and 75 on the side where the terminals 65 and 75 are bent on the surface from which the terminals 65 and 75 of the magnetic body 21 (lower magnetic body 25) are led out. Corresponding portions are cut away from the gap region between the terminals 65 and 75. Accordingly, the portion corresponding to the gap region between the terminals 65 and 75 on the surface of the magnetic body 21 from which the terminals 65 and 75 are derived is reliably separated from the gap region between the terminals 65 and 75 with an extremely simple configuration. be able to. In addition, the decrease in the effective cross-sectional area of the magnetic body 21 can be suppressed low, the inductance value can be suppressed from decreasing, and the magnetic flux density can be suppressed from increasing.

  In the fourth embodiment, the number of the terminals 75 of the second conductor 71 derived from the same surface of the magnetic body 21 is plural, and the first conductivity derived from the same surface of the magnetic body 21 is made. The terminals 65 of the body 61 and the terminals 75 of the second conductor 71 are alternately arranged adjacent to each other. As a result, there are a plurality of gap regions between the terminals 65 and 75 of the first conductor 61 and the second conductor 71, and the sum of the energy concentrated in each gap region is the energy when there is one gap region. It is reduced to about the inverse of the number of gap regions. As a result, the leakage inductance can be further reduced.

  In the fourth embodiment, since the first conductor 61 and the second conductor 71 (base portions 3 and 13) are wide and extend in a flat plate shape, the electrical resistance value is extremely low. A large current can flow. As a result, the magnetic coupling element MC4 can meet the demand for low voltage and large current.

(Fifth embodiment)
FIG. 12 is an overall perspective view showing the magnetic coupling element according to the fifth embodiment, and FIG. 13 is an exploded perspective view showing the magnetic coupling element according to the fifth embodiment. In the description, the terms “upper” and “lower” may be used, which correspond to the vertical direction in FIG.

  As shown in FIGS. 12 and 13, the magnetic coupling element MC5 includes a first conductor 61, a second conductor 71, and a magnetic body 41.

  The magnetic body 41 is disposed so as to surround the first conductor 61 and the second conductor 71, and the first conductor 61 and the second conductor 71 pass through the hollow portion of the magnetic body 41. Yes. Both ends of the base portions 3 and 13 of the first conductor 61 and the second conductor 71 stacked in an electrically insulated state protrude from the magnetic body 41. As a result, the surface of the magnetic body 41 (lower magnetic body 45) from which the terminals 65 and 75 are led out from the gap region between the terminals 65 and 75. In addition, it is preferable that the protrusion amount of the bases 3 and 13 of the first conductor 61 and the second conductor 71 is equal to or greater than the gap between the terminals 65 and 75.

  The terminals 65 of the first conductor 61 are led out from two different surfaces of the magnetic body 41, respectively. Two terminals 75 of the second conductor 71 are also led out from the two different surfaces of the magnetic body 41 from which the terminal 65 of the first conductor 61 is led out. The terminal 65 of the first conductor 61 and the terminal 75 of the second conductor 71 are led out from the same surface of the magnetic body 41 in an adjacent state. The terminals 65 and 75 of the first conductor 61 and the second conductor 71 are bent in the same direction (downward in the present embodiment) substantially parallel to the derived surface of the lower magnetic body 45. Yes. Further, the tip portions of the terminals 65 and 75 are bent along the lower surface of the lower magnetic body 45.

  As described above, in the fifth embodiment, the surface of the magnetic body 41 from which the terminals 65 and 75 are derived is the surface from which the terminals 65 and 75 are derived is the terminal 65 of the first conductor 61 and the second conductor 71. , 75, the magnetic flux density in the vicinity of the gap region between the terminals 65, 75 does not increase even if a strong magnetic field is generated between the terminals 65, 75. As a result, the leakage magnetic flux in the vicinity of the gap region between the terminals 65 and 75 is reduced, and the leakage inductance is reduced.

  Therefore, also in the fifth embodiment, it is possible to increase the coupling coefficient between the first conductor 61 and the second conductor 71 and reduce the leakage inductance.

  In the fifth embodiment, the first conductor 61 and the second conductor 71 protrude from the magnetic body 41 in a state where the first conductor 61 and the second conductor 71 are overlapped with each other, whereby the terminals 65 and 75 are led out. 41 faces away from the gap region between the terminals 65 and 75. Accordingly, the portion corresponding to the gap region between the terminals 65 and 75 on the surface of the magnetic body 41 from which the terminals 65 and 75 are derived is reliably separated from the gap region between the terminals 65 and 75 with an extremely simple configuration. be able to.

  In the fifth embodiment, the magnetic coupling element MC5 can meet the demand for a low voltage and a large current, like the magnetic coupling element MC4 of the fourth embodiment.

  Subsequently, a further modification of the magnetic coupling element according to the present embodiment will be described with reference to FIGS. 14 to 16 are overall perspective views showing modifications of the magnetic coupling element according to the present embodiment.

  The magnetic coupling element MC6 shown in FIG. 14 is different from the magnetic coupling element MC1 according to the first embodiment in the shape of the terminals 5 and 15 of the first conductor 1 and the second conductor 11. In the magnetic coupling element MC6, the terminals 5 and 15 extend on the same plane as the bases 3 and 13 without being bent.

  The magnetic coupling element MC7 shown in FIG. 15 is different from the magnetic coupling element MC2 according to the second embodiment in the shape of the terminals 5 and 15 of the first conductor 1 and the second conductor 11. In the magnetic coupling element MC6, the terminals 5 and 15 extend on the same plane as the bases 3 and 13 without being bent.

  The magnetic coupling element MC8 shown in FIG. 16 is different from the magnetic coupling element MC3 according to the third embodiment in the shape of the terminals 5 and 15 of the first conductor 1 and the second conductor 11. In the magnetic coupling element MC6, the terminals 5 and 15 extend on the same plane as the bases 3 and 13 without being bent.

  In the magnetic coupling elements MC6 to MC8, as in the above-described embodiment, the coupling coefficient between the first conductor 1 and the second conductor 11 can be increased to reduce the leakage inductance. In the magnetic coupling element MC6, a portion corresponding to the gap region between the terminals 5 and 15 on the surface from which the terminals 5 and 15 of the upper magnetic body 23 are led is cut away from the gap region between the terminals 5 and 15. You may form a notch and a hollow part.

  Further, the magnetic coupling elements MC6 to MC8 can meet the demand for a low voltage and large current, like the magnetic coupling element MC1 of the first embodiment.

  Here, according to this embodiment, it is possible to increase the coupling coefficient between the first conductor and the second conductor and reduce the leakage inductance, with reference to examples and comparative examples. Shown in In the following examples and comparative examples, an inductance value, a coupling coefficient, and a leakage inductance were obtained by a simulation calculation (magnetic field analysis by a finite element method) at 1 MHz.

Example 1
As the magnetic coupling element according to Example 1, the magnetic coupling element MC1 of the first embodiment was adopted.

  The first conductor 1 and the second conductor 11 were copper plates having a thickness of 0.3 mm. The width (the length in the left-right direction in FIG. 1) of the bases 3 and 13 of the respective conductors 1 and 11 was 7.6 mm. The width of the gap region between the terminal 5 of the first conductor 1 and the terminal 15 of the second conductor 11 (length in the left-right direction in FIG. 1) was 1 mm.

  The width of the magnetic body 21 (the length in the left-right direction in FIG. 1) is 12 mm, the depth of the magnetic body 21 (the length in the left-right direction in FIG. 2) is 11 mm, and the thickness of the magnetic body 21 (in FIGS. 1 and 2). The length in the vertical direction) was 5 mm. The vertical width of the hollow portion of the magnetic body 21 was 1 mm. The thickness of the lower magnetic body 25 and the thickness of the portion of the upper magnetic body 23 parallel to the bases 3 and 13 of the conductors 1 and 11 were 2 mm. The magnetic body 21 has a magnetic permeability of 30. The depth of the recess 25a was 1 mm.

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 38.7 nH, the coupling coefficient was 0.936, and the leakage inductance was 4.80 nH.

( Reference Example 1 )
As the magnetic coupling element according to Reference Example 1 , the magnetic coupling element MC2 of the second embodiment was adopted. About the 1st conductor 1 and the 2nd conductor 11, it was set as the same conditions as Example 1. FIG.

  The width of the magnetic body 41 (length in the left-right direction in FIG. 4) is 12 mm, the depth of the magnetic body 41 (length in the left-right direction in FIG. 5) is 9 mm, and the thickness of the magnetic body 41 (in FIGS. 4 and 5). The length in the vertical direction) was 5 mm. The vertical width of the hollow portion of the magnetic body 41 was 1 mm. The thickness of the lower magnetic body 45 and the thickness of the portion of the upper magnetic body 43 parallel to the bases 3 and 13 of the conductors 1 and 11 were 2 mm. The magnetic body 41 has a magnetic permeability of 30. The amount of protrusion of the bases 3 and 13 of the first conductor 1 and the second conductor 11 from the side surface of the magnetic body 41 (the surface from which the terminals 5 and 15 of the magnetic body 41 are led out) is about 1 mm.

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 34.5 nH, the coupling coefficient was 0.931, and the leakage inductance was 4.60 nH.

(Example 3)
As the magnetic coupling element according to Example 3, the magnetic coupling element MC4 of the fourth embodiment was adopted. About the magnetic body 21, it was set as the same conditions as Example 1. FIG.

  The first conductor 61 and the second conductor 71 were copper plates having a thickness of 0.3 mm. The width (length in the left-right direction in FIG. 10) of the bases 3 and 13 of the respective conductors 61 and 71 was 7.6 mm. The width of the gap region between the terminal 65 of the first conductor 61 and the terminal 75 of the second conductor 71 (the length in the left-right direction in FIG. 10) was 1 mm.

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 38.9 nH, the coupling coefficient was 0.962, and the leakage inductance was 2.91 nH.

( Reference Example 2 )
As the magnetic coupling element according to Reference Example 2 , the magnetic coupling element MC5 of the fifth embodiment was adopted.
About the 1st conductor 61 and the 2nd conductor 71, it was set as the same conditions as Example 3. FIG. Magnetic body 4
1 was the same as in Reference Example 1 .

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 34.9 nH, the coupling coefficient was 0.958, and the leakage inductance was 2.85 nH.

(Comparative Example 1)
As Comparative Example 1, the magnetic coupling element MC101 shown in FIG. FIG. 17 is an exploded perspective view showing the magnetic coupling element of Comparative Example 1. FIG.

  The magnetic coupling element MC101 includes a first conductor 1, a second conductor 11, and a magnetic body 121. The magnetic body 121 includes an upper magnetic body 123 having a U-shaped core shape and a lower magnetic body 125 having an I-shaped core shape, and surrounds the first conductor 1 and the second conductor 11. Is arranged. A recess portion is not formed in a portion corresponding to the gap region between the terminals 5 and 15 on the surface from which the terminals 5 and 15 of the magnetic body 121 are derived, and the surface of the upper magnetic body 123 and the lower magnetic body 125 The plane is located on the same plane.

  About the 1st conductor 1 and the 2nd conductor 11, it was set as the same conditions as Example 1. FIG.

  The width of the magnetic body 121 (length in the left-right direction in FIG. 17) was 12 mm, the depth of the magnetic body 21 was 11 mm, and the thickness of the magnetic body 121 (length in the vertical direction in FIG. 17) was 5 mm. The vertical width of the hollow portion of the magnetic body 121 was 1 mm. The thickness of the lower magnetic body 125 and the thickness of the portion of the upper magnetic body 123 parallel to the bases 3 and 13 of the conductors 1 and 11 were 2 mm. The magnetic body 121 has a magnetic permeability of 30.

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 41.8 nH, the coupling coefficient was 0.920, and the leakage inductance was 6.43 nH.

(Comparative Example 2)
As Comparative Example 2, the magnetic coupling element MC102 shown in FIG. 18 is an exploded perspective view showing the magnetic coupling element of Comparative Example 2. FIG.

  The magnetic coupling element MC102 includes a first conductor 61, a second conductor 71, and a magnetic body 121. Also in Comparative Example 2, as in Comparative Example 1, no recess is formed in the portion corresponding to the gap region between the terminals 5 and 15 on the surface from which the terminals 5 and 15 of the magnetic body 121 are derived, and the upper side The surface of the magnetic body 123 and the surface of the lower magnetic body 125 are located on the same plane.

  About the 1st conductor 61 and the 2nd conductor 71, it was set as the same conditions as Example 3. FIG. About the magnetic body 121, it was set as the same conditions as the comparative example 1. FIG.

  As a result of the simulation calculation, as shown in FIG. 19, the inductance value was 42.2 nH, the coupling coefficient was 0.953, and the leakage inductance was 3.86 nH.

As can be seen from FIG. 19, in Example 1 and Reference Example 1 , the coupling coefficient is higher than that of Comparative Example 1, and the leakage inductance is reduced. In Example 3 and Reference Example 2 , the coupling coefficient is higher than that of Comparative Example 2, and the leakage inductance is reduced. From the above, the effectiveness of the present embodiment was confirmed. Moreover, in Example 3 and Reference Example 2 , the coupling coefficient is higher and the leakage inductance is smaller than in Example 1 and Reference Example 2 , and the effectiveness of the configuration in which the terminals are alternately arranged adjacent to each other has been confirmed. It was.

  Next, a circuit to which the magnetic coupling element according to the present embodiment is applied will be described with reference to FIGS. FIG. 20 is a circuit diagram showing an example of a circuit to which the magnetic coupling element according to this embodiment is applied. FIG. 21 is an operation waveform diagram of the circuit shown in FIG.

  The circuit shown in FIG. 20 constitutes a tapped inductor type step-down DC-DC converter (Tapped-Inductor Buck Converter) 81 used for a switching power supply. The DC-DC converter 81 obtains an output voltage of about DC1V from DC12V, for example, and is connected to a DC power supply E and a load R.

  The DC-DC converter 81 includes switching elements S1 and S2 configured by MOSFETs, a tapped inductor TI, and a capacitor C. The tapped inductor TI includes coils L1 and L2 that are electromagnetically coupled to each other. The magnetic coupling elements MC1 to MC8 of the above embodiment are applied to the tapped inductor TI, and any one of the first conductors 1 and 61 and the second conductors 11 and 71 constitutes the coil L1, and the other is the coil. L2 is constituted.

  As shown in FIG. 21, the switching elements S1 and S2 are alternately turned on. When the switching element S1 is turned on, a current i1 flows to the capacitor C and the load R through the tapped inductor TI. When the switching element S1 is turned off and the switching element S2 is turned on, a current i2 flows from the coil L2 to the capacitor C and the load R by the energy stored in the tapped inductor TI.

  In the DC-DC converter 81 using the tapped inductor TI, since the current i1 flows through the coils L1 and L2 when the switching element S1 is in an on state, the DC-DC converter 81 is compared with the conventional DC-DC converter including only the coil L2. The current i1 becomes small. Further, by adjusting the turns ratio of the coils L1 and L2, it is possible to obtain a low voltage output at a larger time ratio than in the conventional step-down converter.

  Thus, in the DC-DC converter 81, the tapped inductor TI has one function, and has two functions of an output filter and a voltage conversion. Further, in the DC-DC converter 81, since the current i1 flowing through the switching element S1 is small, the switching loss and the conduction loss of the switching element S1 are reduced, and the efficiency is improved.

  Further, in the above conventional DC-DC converter, since the input voltage is applied as it is to the switching element S2, it is necessary to use one having a relatively high withstand voltage. However, in the DC-DC converter 81, a voltage close to the output voltage is applied to the switching element S2, and a low breakdown voltage, low on-resistance MOSFET can be used.

  In order to increase the transmission efficiency in the DC-DC converter 81, it is necessary to increase the coupling coefficient between the coils L1 and L2, and the magnetic coupling elements MC1 to MC8 of this embodiment are suitable as the tapped inductor TI. When the magnetic coupling elements MC1 to MC8 of the present embodiment are used as the tapped inductor TI, since the leakage inductance is small, the surge voltage generated in the switching element due to the energy due to the leakage inductance is reduced, and the withstand voltage is further increased. A low switching element can be used. Of course, it is not necessary to separately provide a circuit for absorbing the surge voltage.

  The present invention is not limited to the embodiment described above. For example, instead of making the upper magnetic bodies 23, 43, 53 U-shaped and the lower magnetic bodies 25, 45, 55 I-shaped, both magnetic bodies 23, 25, 43, 45, 53, 55 may have a U-shaped core shape. Further, the magnetic bodies 21, 41, 51 may be formed by a method such that both the magnetic bodies 23, 25, 43, 45, 53, 55 have an I-shaped core shape and both sides of the core are bonded. Further, the magnetic bodies 21, 41, 51 may be integrally formed in a cylindrical shape. Further, the stacked conductors 1, 11, 61, 71 may be insert-molded using a metal dust material or the like.

  The tip portions of the terminals 5 and 65 of the first conductors 1 and 61 and the tip portions of the terminals 15 and 75 of the second conductors 11 and 71 are along the lower surfaces of the lower magnetic bodies 25, 45, and 55. However, the present invention is not limited to this. For example, the tip portions of the terminals 5 and 65 of the first conductors 1 and 61 and the tip portions of the terminals 15 and 75 of the second conductors 11 and 71 are moved away from the lower surfaces of the lower magnetic bodies 25, 45, and 55. It may be bent into The tip portions of the terminals 5 and 65 of the first conductors 1 and 61 and the tip portions of the terminals 15 and 75 of the second conductors 11 and 71 may be bent in different directions.

  Further, in the magnetic coupling elements MC4 and MC5 of the fourth and fifth embodiments, the number of the terminals 65 of the first conductor 61 is plural, and they are alternately arranged adjacent to the terminals 75 of the second conductor 71. It may be.

  Further, in the fourth magnetic coupling element MC4, instead of forming the recess 25a, the side where the terminals 65, 75 of the surface are bent is lowered to the surface of the magnetic body 51 from which the terminals 65, 75 are derived. You may comprise so that a level | step difference may be formed.

  The present invention can be applied not only to a tapped inductor used in a tapped inductor type DC-DC converter but also to a transformer used in an insulated DC / DC converter or the like.

1 is an overall perspective view showing a magnetic coupling element according to a first embodiment. It is sectional drawing along the II-II line in FIG. It is a disassembled perspective view which shows the magnetic coupling element which concerns on 1st Embodiment. It is a whole perspective view which shows the magnetic coupling element which concerns on 2nd Embodiment. It is sectional drawing along the VV line in FIG. It is a disassembled perspective view which shows the magnetic coupling element which concerns on 2nd Embodiment. It is a whole perspective view which shows the magnetic coupling element which concerns on 3rd Embodiment. It is sectional drawing along the VIII-VIII line in FIG. It is a disassembled perspective view which shows the magnetic coupling element which concerns on 3rd Embodiment. It is a whole perspective view which shows the magnetic coupling element which concerns on 4th Embodiment. It is a disassembled perspective view which shows the magnetic coupling element which concerns on 4th Embodiment. It is a whole perspective view which shows the magnetic coupling element which concerns on 5th Embodiment. It is a disassembled perspective view which shows the magnetic coupling element which concerns on 5th Embodiment. It is a whole perspective view which shows the modification of the magnetic coupling element which concerns on 1st Embodiment. It is a whole perspective view which shows the modification of the magnetic coupling element which concerns on 2nd Embodiment. It is a whole perspective view which shows the modification of the magnetic coupling element which concerns on 3rd Embodiment. 6 is an exploded perspective view showing a magnetic coupling element of Comparative Example 1. FIG. 10 is an exploded perspective view showing a magnetic coupling element of Comparative Example 2. FIG. It is a graph which shows the result of the simulation calculation in Examples 1-4 and Comparative Examples 1 and 2. It is a circuit diagram which shows an example of the circuit to which the magnetic coupling element which concerns on this embodiment is applied. FIG. 21 is an operation waveform diagram of the circuit shown in FIG. 20.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,61 ... 1st conductor, 3, 13, 63, 73 ... Base, 5, 15, 65, 75 ... Terminal, 11, 71 ... 2nd conductor, 21, 41, 51 ... Magnetic body, 23 , 43, 53... Upper magnetic body, 25, 45, 55... Lower magnetic body, 25a... Depressed portion, 31.

Claims (5)

A first conductor and a second conductor formed in a plate shape and stacked in an electrically insulated state;
A magnetic body disposed so as to surround the first conductor and the second conductor;
It said first conductor includes a base, a terminal for deriving outwardly from two sides extending and having the different magnetic from the base by at least one of each, and
The second conductor includes a base portion that is overlapped with the base portion of the first conductor , a base portion that extends from the base portion, and the terminal of the first conductor is led out. a terminal for deriving outwardly from two different sides by at least one of each has a
The terminals of the first conductor and the second conductor are bent in the same direction;
A portion of the surface of the magnetic body from which the terminal is derived corresponding to a gap region between the terminals on the bent side of the first and second conductors is the first and second conductors. by the one base one of said base body is cut to expose the magnetic coupling elements, characterized in that apart from the gap region between the terminals. The magnetic body is composed of two magnetic bodies,
The magnetic coupling element according to claim 1, wherein a magnetic body located on a side where the terminal is bent is cut out of the two magnetic bodies . A first conductor and a second conductor formed in a plate shape and stacked in an electrically insulated state;
A magnetic body disposed so as to surround the first conductor and the second conductor;
The first conductor has a base, and a terminal extending from the base and led out to at least one each from two different surfaces of the magnetic body,
The second conductor includes a base portion that is overlapped with the base portion of the first conductor, a base portion that extends from the base portion, and the terminal of the first conductor is led out. And at least one terminal led out from two different surfaces, respectively,
The terminals of the first conductor and the second conductor are bent in the same direction;
A step is formed on the surface of the magnetic body from which the terminal is led out so that the bent side of the terminal is lowered and one of the base portions of the first and second conductors is exposed. The magnetic coupling element according to claim 1 , wherein a side of the surface of the magnetic body formed and lowered by the step is bent away from a gap region between the terminals. The magnetic body is composed of two magnetic bodies,
The step is formed by setting the length of the magnetic body located on the bent side of the two magnetic bodies to be shorter than the length of the other magnetic body. The magnetic coupling element according to claim 3. The number of the terminals of the first conductor and the second conductor derived from the same surface of the magnetic body is plural for at least one of the conductors,
To claim 1 or 3, characterized in that said terminal of said terminal and said second conductor of said first conductor derived from the same surface of the magnetic body are arranged side by side alternately The magnetic coupling element as described.

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