Patent Application
20250233515
The present disclosure relates to a switching power supply system device including multiple inductors and multiple power conversion circuits each including respective one of the multiple inductors.
U.S. Pat. No. 8,294,544 describes an M-phase coupled inductor. The M-phase coupled inductor of U.S. Pat. No. 8,294,544 includes a ladder-type magnetic core having multiple inner legs each with a rectangular parallelepiped shape, and multiple windings each wound around the inner leg. A gap is provided between the multiple inner legs.
International Publication No. 2020/035967 describes a switching power supply system device. The switching power supply system device of International Publication No. 2020/035967 includes multiple switching circuit units and a controller. Each of the multiple switching circuit units includes an inductor.
Each of the multiple inductors constituting the switching circuit units includes multiple windings formed on a multilayer printed substrate and magnetic sheets disposed to sandwich the multilayer printed substrate.
In a case of the ladder-type core as disclosed in U.S. Pat. No. 8,294,544, when the number of inductors to be coupled is increased, the inductors are disposed side by side in a lateral or longitudinal direction, and the shape becomes complicated. Further, in the case of the ladder-type core, the winding structure becomes more complicated as the number of inductors to be coupled is increased.
In the case of the ladder-type core as in U.S. Pat. No. 8,294,544 or in a case of sandwiching multiple windings between magnetic sheets as in International Publication No. 2020/035967, small spaces are formed between the multiple windings and a magnetic material (a magnetic body or a magnetic sheet). The spaces above have small relative permeability and large thermal resistance. Accordingly, in the structures above, when magnetic flux density is made high, the volume of the inductor increases.
Accordingly, the present disclosure provides a switching power supply system device including a thin planar array inductor capable of mitigating local heat generation and local increase in magnetic flux density.
The switching power supply system device including a planar array inductor according to the present disclosure includes a power conversion unit configured to couple multiple power conversion circuits in parallel and to obtain an output voltage by combining currents output by respective switching operations, a switching control circuit configured to control the switching operations, and a planar array inductor including multiple power inductors constituting the multiple power conversion circuits.
The planar array inductor includes a planar core, and multiple windings formed in an array relative to the planar core. Each of the multiple windings uses multiple layers of copper foil wiring lines laminated with a nonmagnetic and non-conductive adhesive layer interposed therebetween, and adjacent copper foil wiring lines in the multiple copper foil wiring lines are electrically coupled to each other using an interlayer via conductor. The planar core has a shape covering the multiple windings, and sheet-shaped magnetic materials are pressure-bonded and thermally cured on an inner side portion and an outer side portion of each of the multiple windings. The switching control circuit performs control such that, in an entire switching period for a series of switching operations based on the respective switching operations, a peak value of a current flowing through each of the multiple windings periodically changes, a winding in the multiple windings with the peak value of the current is consecutively moved with elapse of time to control periodic entire switching operations, and, in the planar core, a position and time at which density of magnetic flux becomes maximum are periodically moved, the magnetic flux being generated by the current of each of the multiple windings.
In this configuration, heat generated in the planar core and heat generated in the multiple windings are integrated using thermal conduction and are uniformly distributed in a planar manner, and a local increase in magnetic flux density in the planar core and local heat generation are mitigated.
According to the present disclosure, a switching power supply system device including a planar array inductor may mitigate local heat generation and a local increase in magnetic flux density while achieving a reduction in thickness.
A switching power supply system device including a planar array inductor according to a first embodiment of the present disclosure will be described with reference to the drawings.
As illustrated in
The planar array inductor 10 includes a magnetic body 100. The planar array inductor 10 includes multiple winding conductors 111 and 112 and an interlayer via conductor 119 constituting the inductor 11, multiple winding conductors 121 and 122 and an interlayer via conductor 129 constituting the inductor 12, multiple winding conductors 131 and 132 and an interlayer via conductor 139 constituting the inductor 13, and multiple winding conductors 141 and 142 and an interlayer via conductor 149 constituting the inductor 14.
The planar array inductor 10 includes multiple external terminals P101 and P102 for the inductor 11, multiple external terminals P201 and P202 for the inductor 12, multiple external terminals P301 and P302 for the inductor 13, and multiple external terminals P401 and P402 for the inductor 14. The planar array inductor 10 includes outer coupling-use via conductors Via101 and Via102 for the inductor 11, outer coupling-use via conductors Via201 and Via202 for the inductor 12, outer coupling-use via conductors Via301 and Via302 for the inductor 13, and outer coupling-use via conductors Via401 and Via402 for the inductor 14.
As illustrated in
The winding conductors 111 and 112 are laminated such that the respective planes are parallel to each other. At this time, the winding conductors 111 and 112 are disposed to face each other over substantially the entire circumference.
The winding conductors 111 and 112 are disposed with an adhesive layer ADH (see
A pad conductor 113 for outer coupling is coupled to one end portion of the winding conductor 111. The other end portion of the winding conductor 111 is coupled to one end portion of the winding conductor 112 through the interlayer via conductor 119. Thus, the winding conductors 111 and 112 are electrically coupled to each other with the interlayer via conductor 119. A pad conductor 114 for outer coupling is coupled to the other end portion of the winding conductor 112. With the configuration above, the inductor 11 realizes a thin helical winding having the pad conductor 113 at one end and the pad conductor 114 at the other end.
The helical winding of the inductor 11 is covered with the magnetic body 100. More specifically, the magnetic body 100 is filled in an inner side portion and an outer side portion of the helical winding of the inductor 11 and has a shape without a gap.
The magnetic body 100 is formed using, for example, a metal composite type magnetic material (a metal composite material). More specifically, the magnetic material of the magnetic body 100 is a material in which multiple metal magnetic particles, covered with an insulating resin film such as an epoxy film, are contained in a thermosetting resin.
The magnetic body 100 has a main surface F101 and a main surface F102. The multiple external terminals P101 and P102 are formed on the main surface F101 of the magnetic body 100. The external terminals P101 and P102 each have, for example, a rectangular shape when viewed in plan (the Z-axis direction). The external terminals P101 and P102 each correspond to an “outer electrode” of the present disclosure. The external terminals P101 and P102 are each formed by metal plating using gold (Au) or nickel (Ni).
The pad conductor 113 is coupled to the external terminal P101 through the outer coupling-use via conductor Via101 formed in the magnetic body 100. The pad conductor 114 is coupled to the external terminal P102 through the outer coupling-use via conductor Via102 formed in the magnetic body 100. The outer coupling-use via conductor Via101 is integrally formed with the external terminal P101 and the outer coupling-use via conductor Via102 is integrally formed with the external terminal P102, for example.
With the configuration above, the inductor 11 realizes a planar inductor having a planar core whose thickness (a dimension in the Z-axis direction in the drawings) is smaller than dimensions in other directions (dimensions in the X-axis direction and the Y-axis direction in the drawings) constituting the plane along which the winding conductor is formed.
The basic configuration of each of the multiple inductors 12, 13, and 14 is the same as that of the inductor 11. The configuration of each of the multiple inductors 12, 13, and 14, therefore, will schematically be described.
The winding conductors 121 and 122 are laminated and coupled to each other via the interlayer via conductor 129. Thus, the inductor 12 realizes a helical winding. The helical winding of the inductor 12 is covered with the magnetic body 100.
One end portion of the winding conductor 121 is coupled to the external terminal P201 through a pad conductor 123 and the outer coupling-use via conductor Via201. The other end portion of the winding conductor 122 is coupled to the external terminal P202 through a pad conductor 124 and the outer coupling-use via conductor Via202.
The winding conductors 131 and 132 are laminated and coupled to each other via the interlayer via conductor 139. Thus, the inductor 13 realizes a helical winding. The helical winding of the inductor 13 is covered with the magnetic body 100.
One end portion of the winding conductor 131 is coupled to the external terminal P301 through a pad conductor 133 and the outer coupling-use via conductor Via301. The other end portion of the winding conductor 132 is coupled to the external terminal P302 through a pad conductor 134 and the outer coupling-use via conductor Via302.
The winding conductors 141 and 142 are laminated and coupled to each other via the interlayer via conductor 149. Thus, the inductor 14 realizes a helical winding. The helical winding of the inductor 14 is covered with the magnetic body 100.
One end portion of the winding conductor 141 is coupled to the external terminal P401 through a pad conductor 143 and the outer coupling-use via conductor Via401. The other end portion of the winding conductor 142 is coupled to the external terminal P402 through a pad conductor 144 and the outer coupling-use via conductor Via402.
The helical winding of the inductor 11, the helical winding of the inductor 12, the helical winding of the inductor 13, and the helical winding of the inductor 14 described above are disposed in an array at intervals in a direction (the X-axis direction in the drawings) orthogonal to a direction in which the multiple windings thereof are laminated (the Z-axis direction in the drawings).
The helical winding of the inductor 11, the helical winding of the inductor 12, the helical winding of the inductor 13, and the helical winding of the inductor 14 disposed in an array in the manner described above are covered with the magnetic body 100. Thus, the multiple inductors 11, 12, 13, and 14 are disposed side by side in a planar manner in a direction orthogonal to a thickness direction of the magnetic body 100 being a planar core. As a result, the planar array inductor 10 has a thin outer shape.
In other words, as illustrated in
In the configuration above, the helical winding of the inductor 11, the helical winding of the inductor 12, the helical winding of the inductor 13, and the helical winding of the inductor 14 are covered with the magnetic body 100 having no local gap. In other words, there is no gap in the magnetic body 100, and further, there is no gap between the magnetic body 100 and the winding conductor of each of the multiple inductors 11, 12, 13, and 14 as well. More specifically, no gap is present between the magnetic body 100 and the inductors 11, 12, 13, and 14 on both the inner side portion and the outer side portion of the winding conductor of each of the multiple inductors 11, 12, 13, and 14, and the magnetic body 100 is in close contact with the inductors 11, 12, 13, and 14.
Thus, the planar array inductor 10 can mitigate a local lowering in relative permeability. As a result, even when the planar array inductor 10 is small and thin, inductance of each of the multiple inductors 11, 12, 13, and 14 can be increased.
The planar array inductor 10 has no portion where thermal resistance is locally high. Further, since the magnetic body 100 is made of a metal composite type magnetic material, the planar array inductor 10 has high thermal conductivity and can make thermal resistance low. Thus, heat generated by the flow of current through the multiple inductors 11, 12, 13, and 14 of the planar array inductor 10 does not remain in a local portion but is diffused over the entire magnetic body 100. Thus, the planar array inductor 10 can mitigate local heat generation.
In the configuration above, for example, when the number of inductors is increased, the number of inductors disposed side by side in a planar manner only need be increased, and the area of the magnetic body 100 need be increased accordingly. On the other hand, when the number of inductors is decreased, the number of inductors disposed side by side in a planar manner only need be decreased, and the area of the magnetic body 100 need be reduced accordingly. As a result, the shape of the planar array inductor 10 does not become complicated when the number of inductors is changed.
Note that the helical winding of the inductor 11, the helical winding of the inductor 12, the helical winding of the inductor 13, and the helical winding of the inductor 14 are disposed such that end portions coupled to the respective external terminals are on the same side of the respective helical windings.
As illustrated in
The adhesive layer ADH is made thinner than the copper foils M101 and M102, so that the copper foils M101 and M102 are bonded with a small gap GAP therebetween. Thus, the winding conductors 111 and 112 of the inductor 11 are disposed while being fixed with the small gap GAP therebetween.
As illustrated in
As illustrated in
As illustrated in
As illustrated in
Thereafter, although not illustrated, the magnetic body 100 is subjected to laser processing to form a hole for an outer coupling-use via conductor, and the hole is filled with copper-plating, nickel-plating, and Au-plating, thereby forming the outer coupling-use via conductors Via101 and Via102 and the external terminals P101 and P102.
A DC power supply is coupled between a Hi-side power supply input terminal and a Low-side power supply input terminal of the switching power supply system device 80. The Hi-side power supply input terminal is coupled to a positive electrode of the DC power supply, and the Low-side power supply input terminal is coupled to a negative electrode of the DC power supply.
Schematically, the switching power supply system device 80 constitutes a power conversion unit by coupling the multiple power conversion circuits 81 to 84 in parallel, and obtains an output voltage by combining outputs of switching operations of the respective multiple power conversion circuits 81 to 84.
The power conversion circuit 81 includes a driver circuit 810, switching elements Q81H and Q81L, and the inductor 11 of the planar array inductor 10. The driver circuit 810 is realized by an analog IC. The switching elements Q81H and Q81L are each a power semiconductor element, and for example, a power MOSFET.
The driver circuit 810 is coupled to gate terminals of the switching elements Q81H and Q81L. The driver circuit 810 performs switching control of the switching elements Q81H and Q81L based on a control signal for the power conversion circuit 81 (for the driver circuit 810) from the switching control circuit 800.
A drain terminal of the switching element Q81H is coupled to the Hi-side power supply input terminal of the switching power supply system device 80. A source terminal of the switching element Q81H is coupled to a drain terminal of the switching element Q81L. A source terminal of the switching element Q81L is coupled to the Low-side power supply input terminal of the switching power supply system device 80 (a terminal coupled to a reference electric potential line). The reference electric potential line couples the Low-side power supply input terminal (a terminal coupled to the negative electrode of the DC power supply) of the switching power supply system device 80 and a Low-side output terminal (a terminal coupled to a negative electrode of a load 89) of the switching power supply system device 80.
A node between the source terminal of the switching element Q81H and the drain terminal of the switching element Q81L are coupled to the external terminal P101 of the planar array inductor 10. The external terminal P101 is coupled to one side terminal of the inductor 11. The other side terminal of the inductor 11 is coupled to the external terminal P102.
The power conversion circuit 82 includes a driver circuit 820, switching elements Q82H and Q82L, and the inductor 12 of the planar array inductor 10. The driver circuit 820 is realized by an analog IC. The switching elements Q82H and Q82L are each a power semiconductor element, and for example, a power MOSFET.
The driver circuit 820 is coupled to gate terminals of the switching elements Q82H and Q82L. The driver circuit 820 performs switching control of the switching elements Q82H and Q82L based on a control signal for the power conversion circuit 82 (for the driver circuit 820) from the switching control circuit 800.
A drain terminal of the switching element Q82H is coupled to the Hi-side power supply input terminal of the switching power supply system device 80. A source terminal of the switching element Q82H is coupled to a drain terminal of the switching element Q82L.
A source terminal of the switching element Q82L is coupled to the Low-side power supply input terminal of the switching power supply system device 80 (a terminal coupled to the reference electric potential line).
A node between the source terminal of the switching element Q82H and the drain terminal of the switching element Q82L are coupled to the external terminal P201 of the planar array inductor 10. The external terminal P201 is coupled to one side terminal of the inductor 12. The other side terminal of the inductor 12 is coupled to the external terminal P202.
The power conversion circuit 83 includes a driver circuit 830, switching elements Q83H and Q83L, and the inductor 13 of the planar array inductor 10. The driver circuit 830 is realized by an analog IC. The switching elements Q83H and Q83L are each a power semiconductor element, and for example, a power MOSFET.
The driver circuit 830 is coupled to gate terminals of the switching elements Q83H and Q83L. The driver circuit 830 performs switching control of the switching elements Q83H and Q83L based on a control signal for the power conversion circuit 83 (for the driver circuit 830) from the switching control circuit 800.
A drain terminal of the switching element Q83H is coupled to the Hi-side power supply input terminal of the switching power supply system device 80. A source terminal of the switching element Q83H is coupled to a drain terminal of the switching element Q83L. A source terminal of the switching element Q83L is coupled to the Low-side power supply input terminal of the switching power supply system device 80 (a terminal coupled to the reference electric potential line).
A node between the source terminal of the switching element Q83H and the drain terminal of the switching element Q83L are coupled to the external terminal P301 of the planar array inductor 10. The external terminal P301 is coupled to one side terminal of the inductor 13. The other side terminal of the inductor 13 is coupled to the external terminal P302.
The power conversion circuit 84 includes a driver circuit 840, switching elements Q84H and Q84L, and the inductor 14 of the planar array inductor 10. The driver circuit 840 is realized by an analog IC. The switching elements Q84H and Q84L are each a power semiconductor element, and for example, a power MOSFET.
The driver circuit 840 is coupled to gate terminals of the switching elements Q84H and Q84L. The driver circuit 840 performs switching control of the switching elements Q84H and Q84L based on a control signal for the power conversion circuit 84 (for the driver circuit 840) from the switching control circuit 800.
A drain terminal of the switching element Q84H is coupled to the Hi-side power supply input terminal of the switching power supply system device 80. A source terminal of the switching element Q84H is coupled to a drain terminal of the switching element Q84L. A source terminal of the switching element Q84L is coupled to the Low-side power supply input terminal of the switching power supply system device 80 (a terminal coupled to the reference electric potential line).
A node between the source terminal of the switching element Q84H and the drain terminal of the switching element Q84L are coupled to the external terminal P401 of the planar array inductor 10. The external terminal P401 is coupled to one side terminal of the inductor 14. The other side terminal of the inductor 14 is coupled to the external terminal P402.
The external terminals P102, P202, P302, and P402 are coupled to one another, and the node between them is coupled to a Hi-side output terminal of the switching power supply system device 80.
The capacitor 88 is a smoothing capacitor, and is coupled between the Hi-side output terminal and the Low-side output terminal coupled to the reference electric potential line.
In the configuration above, the switching control circuit 800 performs multi-phase control depending on an output voltage and an output current to the load 89. More specifically, the switching control circuit 800 selects the power conversion circuit to be driven depending on the output voltage and the output current. The switching control circuit 800 generates a control signal so as to sequentially drive the power conversion circuit to be driven depending on a period of the switching operation of the switching element of the power conversion circuit to be driven.
By performing such multi-phase control, the switching power supply system device 80 can periodically change a peak value of the current, flowing through each of the multiple windings constituting the multiple inductors 11, 12, 13, and 14, in the period of the switching operation. Further, the switching power supply system device 80 can periodically move, in the magnetic body 100, a position and time at which density of magnetic flux becomes the maximum, the magnetic flux being generated by the current of each of the multiple windings constituting the multiple inductors 11, 12, 13, and 14 in the magnetic body 100.
Thus, the switching power supply system device 80 including the planar array inductor 10 can integrate heat using thermal conduction and uniformly distribute the heat in a planar manner, the heat being generated in the magnetic body 100 and in the multiple windings constituting the multiple inductors 11, 12, 13, and 14. As a result, the switching power supply system device 80 including the planar array inductor 10 can mitigate a local increase in magnetic flux density of the magnetic body 100 while being thin.
In particular, with not including a gap inside, the planar array inductor 10 can more effectively mitigate local heat generation, and can more effectively mitigate a local increase in magnetic flux density of the magnetic body 100.
With the above-described configuration, the switching power supply system device 80 including the planar array inductor 10 can mitigate heat generation, reduce an output voltage ripple in the switching power supply system device 80, and mitigate generation of electromagnetic noise by changing a peak value of a current. As a result, the switching power supply system device 80 including the planar array inductor 10 can realize a high-efficiency and high-performance switching power supply system device in which heat generation is mitigated.
Further, by performing the multi-phase control, the switching power supply system device 80 can also obtain the following operational effect.
As illustrated in
As illustrated in
As described above, the switching power supply system device 80 is realized in a shape in which multiple functional layers are laminated. At this time, since the multiple inductors 11, 12, 13, and 14 are formed by the planar array inductor 10, the switching power supply system device 80 can realize a structure in which the above-described multiple functional layers are laminated.
With the structure above, the switching power supply system device 80 can be reduced in planar area.
Although an aspect in which the above-described planar array inductor 10 uses the winding conductor being substantially rectangular in plan view, the planar shape of the winding conductor is not limited thereto. For example, the planar shape of the winding conductor may be a circular shape or the like.
A switching power supply system device including a planar array inductor according to a second embodiment of the present disclosure will be described with reference to the drawings.
As illustrated in
The planar array inductor 10A includes multiple inductors 11A, 12A, 13A, and 14A. The multiple inductors 11A, 12A, 13A, and 14A are each a so-called center-tapped winding.
A winding portion of the inductor 11A includes winding conductors 111A and 112A. The winding conductors 111A and 112A are formed by a center conductor and two winding conductors disposed on both sides of the center conductor. The winding conductors 111A and 112A are coupled to each other via an interlayer via conductor 119A. The winding conductors 111A and 112A are laminated and bonded with a small gap therebetween with an adhesive, which is not illustrated. A pad conductor 113A is coupled to the winding conductor 111A, and a pad conductor 114A is coupled to the winding conductor 112A.
The winding portion of the inductor 12A includes winding conductors 121A and 122A, an interlayer via conductor 129A, and pad conductors 123A and 124A, and has the same configuration as the winding portion of the inductor 11A.
The winding portion of the inductor 13A includes winding conductors 131A and 132A, an interlayer via conductor 139A, and pad conductors 133A and 134A, and has the same configuration as the winding portion of the inductor 11A.
The winding portion of the inductor 14A includes winding conductors 141A and 142A, an interlayer via conductor 149A, and pad conductors 143A and 144A, and has the same configuration as the winding portion of the inductor 11A.
The respective winding portions of the inductors 11A, 12A, 13A, and 14A are disposed in an array in a planar manner as illustrated in
With the configuration above, the planar array inductor 10A can achieve the same operational effects as those of the planar array inductor 10. Further, since the planar array inductor 10A has the center-tapped winding, magnetic coupling between adjacent windings can be mitigated. As a result, the planar array inductor 10A can shorten a distance between adjacent windings and can make the planar shape small.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-172341 | Oct 2022 | JP | national |
This application claims benefit of priority to International Patent Application No. PCT/JP2023/038301, filed Oct. 24, 2023, and to Japanese Patent Application No. 2022-172341, filed Oct. 27, 2022, the entire contents of each are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/038301 | Oct 2023 | WO |
| Child | 19096186 | US |
