Coil component and switching power supply device equipped with the same

Abstract

To provide a coil component comprising a heat dissipation structure in which a heat dissipation property is improved by suppressing a temperature rise of a core in simple configuration, and a switching power supply device with the same packaged therein.SOLUTION: A coil component comprises: a first magnetic core 11 including a first tabular part 111; a second magnetic core 12 including a second tabular part 121; a winding wire 13 including an air-core part 131; a first heat dissipation plate 14 including a first heat dissipation planar part 141 and a first heat conduction part 142; and a second heat dissipation plate 15 including a second heat dissipation planar part 151 and a second heat conduction part 152. At least any one of the first tabular part 111 and the second tabular part 121 includes a middle leg 112, the middle leg is inserted through the air-core part of the winding wire, and the first magnetic core 11 and the second magnetic core 12 are combined in such a manner that the first tabular part 111 and the second tabular part 121 are opposed. The first heat dissipation planar part 141 and the first tabular part 111 are adhered and the second heat dissipation planar part 151 and the second tabular part 121 are adhered, respectively. The first heat conduction part 142 and the second heat conduction part 152 are connected.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a coil component and a switching power supply device equipped with the same, and more particularly to a coil component equipped with a heat dissipation structure and a switching power supply device equipped with the same. [Background technology]

[0002] For example, magnetic elements such as coil components with cores are inevitably used in power supplies, such as switching power supplies. Temperature rise in magnetic elements is a major focus when designing switching power supplies and is a bottleneck in improving product performance. When using coil components, the core temperature rises due to the effects of heat generated from the coil (copper loss) and heat generated from the core (iron loss). Thus, magnetic elements such as coil components installed in switching power supplies are required to efficiently dissipate heat generated from the coil or core and effectively suppress temperature rise in the magnetic elements.

[0003] For this reason, as a magnetic component, for example, Patent Document 1 discloses an inductor element in which heat generated from the edgewise coil 3 is dissipated through the upper core 5 and the lower core 7. In such an inductor element, the heat generated from the edgewise winding 3 accumulates in the cores (upper core 5 and lower core 7), and when the cores rise to a certain temperature and become excessively high, the core characteristics deteriorate and eventually saturate, resulting in a loss of inductance characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-146530 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above problems, and aims to provide a coil component having a heat dissipation structure with high heat dissipation properties that can suppress a rise in core temperature with a simple configuration, and a switching power supply device equipped with the same. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a coil component according to one embodiment of the present invention comprises a first magnetic core having a first flat plate portion, a second magnetic core having a second flat plate portion, a winding having an air-core portion, a first heat dissipation plate having a first heat dissipation plane portion and a first heat conduction portion, and a second heat dissipation plate having a second heat dissipation plane portion and a second heat conduction portion, wherein at least one of the first flat plate portion and the second flat plate portion has a center leg, the center leg is inserted into the air-core portion, the first magnetic core and the second magnetic core are combined so that the first flat plate portion and the second flat plate portion face each other, the first heat dissipation plane portion and the first flat plate portion and the second heat dissipation plane portion and the second flat plate portion are in close contact with each other, and the first heat conduction portion and the second heat conduction portion are connected.

[0007] In this way, a first heat dissipation plate having a first heat dissipation flat portion and a first heat conduction portion and a second heat dissipation plate having a second heat dissipation flat portion and a second heat conduction portion are attached to the first magnetic core and the second magnetic core, respectively, and the first heat conduction portion, which is an end of the first heat dissipation plate, is connected to the second heat conduction portion, which is an end of the second heat dissipation plate. By closely adhering the first heat dissipation plate and the second heat dissipation plate to the first magnetic core and the second magnetic core, respectively, the heat from the first magnetic core and the second magnetic core is dissipated to the first heat dissipation plate and the second heat dissipation plate. Furthermore, the heat dissipated to the first heat dissipation plate and the second heat dissipation plate passes through the connection between the first heat conduction portion formed on the first heat dissipation plate and the second heat conduction portion formed on the second heat dissipation plate, thereby reducing the temperature difference between the first magnetic core and the second magnetic core. This type of heat dissipation structure completely eliminates the gap between the heat dissipation metal plate and the magnetic core plane caused by the tolerance of the magnetic core thickness, and has a simple configuration and high heat dissipation performance, so it can efficiently suppress the temperature rise of the core.

[0008] In the coil component according to one aspect of the present invention, at least one of the first and second thermally conductive portions preferably has a notch, and the other thermally conductive portion is solder-connected to the notch, thereby facilitating the solder connection between the first and second thermally conductive portions.

[0009] Furthermore, in a coil component according to one embodiment of the present invention, preferably, the first heat dissipation flat portion and the second heat dissipation flat portion are each an axisymmetric polygon formed with four or more sides when viewed in a plane, and in the first heat dissipation flat portion, the first heat conduction portion is formed from two sides extending from both ends of one side of a gap formed by combining the first magnetic core and the second magnetic core, on the gap side from which the lead-out portion of the winding is drawn out, and in the second heat dissipation flat portion, the second heat conduction portion is formed from two sides extending from both ends of one side of the gap side.

[0010] Furthermore, in a coil component according to one embodiment of the present invention, preferably, the first heat dissipation flat portion and the second heat dissipation flat portion are each polygons formed with ten or more sides when viewed in a plane, and in the first heat dissipation flat portion, the first heat conduction portion is formed from at least two sides of the gap formed by combining the first magnetic core and the second magnetic core, excluding the two sides on the gap side from which the lead-out portion of the winding is led out, and in the second heat dissipation flat portion, the second heat conduction portion is formed from at least two sides excluding the two sides on the gap side.

[0011] In the coil component according to one aspect of the present invention, the first heat dissipation metal plate and the second heat dissipation metal plate preferably have the same shape, thereby enabling a heat dissipation structure with high heat dissipation performance to be achieved with a single type of heat dissipation metal plate.

[0012] A switching power supply according to one aspect of the present invention is a switching power supply having a heat dissipation member, wherein the heat dissipation member is equipped with a coil component thermally connected to the first heat dissipation flat portion or the second heat dissipation flat portion. In this way, the first heat dissipation plate or the second heat dissipation plate is thermally connected to the heat dissipation member to dissipate heat, thereby more efficiently suppressing the temperature rise of the core.

[0013] In the switching power supply device according to the aspect of the present invention, the heat dissipation member is preferably a metal substrate such as an aluminum substrate.

[0014] According to the present invention, it is possible to provide a coil component having a heat dissipation structure with high heat dissipation properties that can suppress a rise in core temperature with a simple configuration, and a switching power supply device equipped with the coil component. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a schematic configuration of a coil component according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view showing the schematic configuration of the coil component and the heat dissipation metal plate according to the embodiment. [Figure 3] 1 is an exploded perspective view showing a schematic configuration of a core, a coil, a spacer, and a heat dissipation metal plate of a coil component according to an embodiment of the present invention. FIG. [Figure 4] FIG. 10 is a perspective view showing a schematic configuration of a first heat dissipation metal plate and a second heat dissipation metal plate of a first modified example of the coil component according to the present embodiment. [Figure 5] FIG. 10 is a perspective view showing a schematic configuration of a first heat dissipation metal plate and a second heat dissipation metal plate of a second modified example of the coil component according to the present embodiment. [Figure 6] FIG. 10 is a perspective view showing a schematic configuration of a first heat dissipation metal plate and a second heat dissipation metal plate of a third modified example of the coil component according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are designated by the same reference numerals, and redundant explanations will be omitted.

[0017] The switching power supply device according to this embodiment includes a heat dissipation member and a coil component 1, and the coil component 1 is mounted on the heat dissipation member.

[0018] In this embodiment, the heat dissipation member is a metal substrate such as an aluminum substrate. This makes it easy to configure the heat dissipation member. However, the heat dissipation member is not limited to a metal substrate such as an aluminum substrate, and any material having good heat dissipation properties may be used as the substrate.

[0019] Fig. 1 is a perspective view showing a schematic configuration of a coil component according to this embodiment. Fig. 2 is an exploded perspective view showing a schematic configuration of the coil component and a heat dissipation metal plate according to this embodiment. Fig. 3 is an exploded perspective view showing a schematic configuration of a core, coil, spacer, and heat dissipation metal plate of the coil component according to this embodiment.

[0020] As shown in Figures 1 to 3, the coil device 1 comprises a first magnetic core 11 having a first flat plate portion 111 with a center leg 112, a second magnetic core 12 having a second flat plate portion 121, a winding 13 having an air core portion 131, a first heat dissipation plate 14 having a first heat dissipation flat portion 141 and a first heat conduction portion 142, and a second heat dissipation plate 15 having a second heat dissipation flat portion 151 and a second heat conduction portion 152, and is suitable for use as one of the magnetic components.

[0021] Although not shown in FIGS. 1 to 3, the center leg is formed not only on the first flat plate portion 111 but also on the second flat plate portion 121.

[0022] The center leg may be formed only on the first flat plate portion or only on the second flat plate portion.

[0023] Furthermore, at least one of the first flat plate portion and the second flat plate portion that are the core of the coil device 1 may have a center leg.

[0024] As shown in FIGS. 1 to 3, outer legs are formed at both ends of the first flat plate portion 111 and the second flat plate portion 121, respectively.

[0025] Alternatively, outer legs may be formed on both ends of only one of the first flat plate portion 111 and the second flat plate portion 121.

[0026] The first magnetic core 11 and the second magnetic core 12 are made of a magnetic material such as ferrite.

[0027] The first magnetic core 11 and the second magnetic core 12 are assembled together so that the center leg 112 of the first magnetic core 11 passes through the air-core portion 131 located approximately in the center of the winding 13, and the first flat plate portion 111 and the second flat plate portion 121 face each other (although not shown, the center leg of the second magnetic core 12 also passes through the air-core portion 131). This results in a structure in which the winding 13 is sandwiched between the first magnetic core 11 and the second magnetic core 12 via the spacers 16 and 17, respectively. Here, the spacers 16 and 17 function for insulation and / or to accommodate dimensional tolerances of the cores and windings.

[0028] The winding 13 has two lead-out portions 132. These two lead-out portions 132 are drawn from the end of the winding 13 to the outside through a gap formed by the first flat plate portion 111, the second flat plate portion, and the outer leg, by combining the first magnetic core 11 and the second magnetic core 12.

[0029] The first heat dissipation flat portion 141 and the first flat plate portion 111 are in close contact with each other, and the second heat dissipation flat portion 151 and the second flat plate portion 121 are in close contact with each other, thereby thermally connecting the first heat dissipation flat portion 141 and the first flat plate portion 111, and thermally connecting the second heat dissipation flat portion 151 and the second flat plate portion 121. This makes it easy to conduct heat generated in the first magnetic core 11 to the first heat dissipation plate 14, and heat generated in the second magnetic core 12 to the second heat dissipation plate 15. In order to efficiently conduct heat generated in the magnetic cores to the heat dissipation plate members, it is preferable that the first heat dissipation plate 14 and the second heat dissipation plate 15 are each made of a material with good heat dissipation properties, such as metal.

[0030] In addition, the first heat dissipation flat portion 141 and the first flat plate portion 111 may be configured to be in close contact with each other so that a highly thermally conductive silicone resin or other highly thermally conductive material is filled between the first heat dissipation flat portion 141 and the first flat plate portion 111, and the second heat dissipation flat portion 151 and the second flat plate portion 121 may be configured to be in close contact with each other so that a highly thermally conductive silicone resin or other highly thermally conductive material is filled between the second heat dissipation flat portion 151 and the second flat plate portion 121.

[0031] The first thermally conductive member 142 and the second thermally conductive member 152 are connected to each other. Specifically, the inner surface of the first thermally conductive member 142 and the outer surface of the second thermally conductive member 152 are in contact with each other.

[0032] In this embodiment, the first thermally conductive portion 142 and the second thermally conductive portion 152 are in contact with each other over the entire width direction, but they may be configured to be in contact with each other only partially in the width direction.

[0033] Alternatively, the outer surface of the first heat conductive portion 142 and the inner surface of the second heat conductive portion 152 may be in contact with each other.

[0034] In addition, the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 may each have multiple heat conductive portions, and the inner surface of at least one first heat conductive portion 142 and the outer surface of one second heat conductive portion 152 may be in contact with each other, and the outer surface of at least another first heat conductive portion 142 and the inner surface of another second heat conductive portion 152 may be in contact with each other.

[0035] In this way, a first heat dissipation plate having a first heat dissipation plane portion and a first heat conduction portion is attached to the first magnetic core, and a second heat dissipation plate having a second heat dissipation plane portion and a second heat conduction portion is attached to the second magnetic core, respectively. By connecting the first heat conduction portion, which is an end of the first heat dissipation plate, to the second heat conduction portion, which is an end of the second heat dissipation plate, the first heat dissipation plate and the second heat dissipation plate are closely attached to the first magnetic core and the second magnetic core, respectively. Furthermore, the heat dissipated to the first heat dissipation plate and the second heat dissipation plate passes through the connection portion between the first heat conduction portion formed on the first heat dissipation plate and the second heat conduction portion formed on the second heat dissipation plate, thereby reducing the temperature difference between the first and second heat dissipation plate, and as a result, the temperature difference between the first magnetic core and the second magnetic core is also reduced. This type of heat dissipation structure completely eliminates the gap between the heat dissipation metal plate and the magnetic core plane due to the tolerance of the magnetic core thickness, and has a simple configuration and high heat dissipation properties, so it can efficiently suppress the temperature rise of the magnetic core.

[0036] Furthermore, in this embodiment, the first thermally conductive portion 142 has a substantially U-shaped notch 143, and the second thermally conductive portion 152 has a substantially U-shaped notch 153, so that the inner surface of the first thermally conductive portion 142 and the outer surface of the second thermally conductive portion 152 are in contact with each other, and the second thermally conductive portion 152 and the notch 143 are solder-connected. This facilitates the solder connection between the first thermally conductive portion and the second thermally conductive portion.

[0037] In addition, in a configuration in which the outer surface of first thermally conductive portion 142 and the inner surface of second thermally conductive portion 152 are in contact with each other, first thermally conductive portion 142 and notch portion 153 are connected by soldering.

[0038] In the present embodiment, the notch is provided in both the first and second thermally conductive portions, but either one of the first and second thermally conductive portions may have the notch, and the notch may be soldered to the other thermally conductive portion. Furthermore, the shape of the notch is not limited to a substantially U-shape, and may be various shapes, such as a substantially semicircular shape, a rectangular shape with one side open, or a substantially V-shape.

[0039] In this embodiment, the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 are each configured as a decagon with 10 sides in a plan view. That is, the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 each have 10 sides. However, the shapes of the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 are not limited to this, and the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 may each be a polygon with 11 or more sides in a plan view.

[0040] Among the gaps formed by combining the first magnetic core and the second magnetic core on the ten sides of the first heat dissipation flat portion 141, two first heat conductive portions 142 are formed on sides L3 and L4 that extend from ends L1a and L2a, respectively, opposite the junction of the two sides L1 and L2 of two sides L1 and L2 on the gap side from which the lead-out portion 132 of the winding 13 is drawn out. Similarly, among the gaps formed by combining the first magnetic core and the second magnetic core on the ten sides of the second heat dissipation flat portion 151, two second heat conductive portions 152 are formed on sides L7 and L8 that extend from ends L5a and L6a, respectively, opposite the junction of the two sides L5 and L6 of two sides L5 and L6 on the gap side from which the lead-out portion 132 of the winding 13 is drawn out. That is, the first thermally conductive portion 142 extends from sides L3 and L4 of the ten sides of the first heat dissipation flat portion 141 in a direction approximately perpendicular to the first heat dissipation flat portion 141 (illustrated as extending upward in FIG. 1). The second thermally conductive portion 152 extends from sides L7 and L8 of the ten sides of the second heat dissipation flat portion 151 in a direction approximately perpendicular to the second heat dissipation flat portion 151 (illustrated as extending downward in FIG. 1). Thus, in the coil device 1, the first thermally conductive portion 142 and the second thermally conductive portion 152 are closely attached to each other and overlap each other. Furthermore, the first heat conducting portion 142 is formed from the side of the gap formed by combining the first magnetic core and the second magnetic core in the first heat dissipation flat portion 141 that is adjacent to the side of the gap from which the pull-out portion 132 of the winding 13 is pulled out, and the second heat conducting portion 152 is formed from the side of the gap formed by combining the first magnetic core and the second magnetic core in the second heat dissipation flat portion 151 that is adjacent to the side of the gap from which the pull-out portion 132 of the winding 13 is pulled out, so that the pull-out portion 132 of the winding 13 is pulled out without being obstructed by the first heat conducting portion 142 and the second heat conducting portion 152.

[0041] Note that, as long as the first heat conductive portion 142 and the second heat conductive portion 152 can be configured to be in close contact with each other so as to overlap, the first heat conductive portion 142 may be formed from any two or more of eight sides of the ten sides of the first heat dissipation flat portion 141, among the gaps formed by combining the first magnetic core and the second magnetic core, excluding two sides L1 and L2 on the gap side from which the lead-out portion 132 of the winding 13 is drawn. Similarly, the second heat conductive portion 152 may be formed from any two or more of eight sides of the ten sides of the second heat dissipation flat portion 151, among the gaps formed by combining the first magnetic core and the second magnetic core, excluding two sides L5 and L6 on the gap side from which the lead-out portion 132 of the winding 13 is drawn.

[0042] In this embodiment, the first heat dissipation metal plate 14 and the second heat dissipation metal plate 15 have the same shape. However, this is not limited to this, and the first heat dissipation metal plate 14 and the second heat dissipation metal plate 15 may have different shapes as long as the first heat conduction portion 142 extending from the side of the first heat dissipation flat portion 141 and the second heat conduction portion 152 extending from the side of the second heat dissipation flat portion 151 can be in surface contact with each other in the coil device 1.

[0043] In this embodiment, the first heat dissipation flat portion 141 is thermally connected to the heat dissipation member. However, this is not limited to this, and the second heat dissipation flat portion 151 may also be thermally connected to the heat dissipation member. In this way, the first heat dissipation flat portion 141 or the second heat dissipation flat portion 151 is thermally connected to the heat dissipation member to dissipate heat, which further suppresses the temperature rise of the magnetic core.

[0044] In addition, the first heat dissipation flat portion 141 or the second heat dissipation flat portion 151 may be configured to be connected to a heat dissipation member such as a metal substrate using a material with high thermal conductivity, or the first heat dissipation flat portion 141 or the second heat dissipation flat portion 151 may be configured to be directly soldered to a heat dissipation member such as a metal substrate.

[0045] 4 is a perspective view showing a schematic configuration of a first heat dissipation plate 14A and a second heat dissipation plate 15A of a first modified example of a coil component according to the present embodiment. As shown in FIG. 4, the first heat dissipation plate 14A of this modified example includes a first heat conduction portion 142A, and the second heat dissipation plate 15A includes a second heat conduction portion 152A.

[0046] 5 is a perspective view showing a schematic configuration of a first heat dissipation plate 14B and a second heat dissipation plate 15B of a second modified example of the coil component according to the present embodiment. As shown in FIG. 5, the first heat dissipation plate 14B of this modified example includes a first heat conduction portion 142B, and the second heat dissipation plate 15B includes a second heat conduction portion 152B.

[0047] 6 is a perspective view showing a schematic configuration of a first heat dissipation plate and a second heat dissipation plate of a third modified example of a coil component according to the present embodiment. As shown in FIG. 6, the first heat dissipation plate 14C according to this modified example includes a first heat conduction portion 142C, and the second heat dissipation plate 15C includes a second heat conduction portion 152C.

[0048] Although preferred embodiments of the present invention have been described in detail above, various changes and modifications are possible without departing from the spirit and scope of the present invention. For example, in the above embodiment, the first heat dissipation flat portion 141 and the second heat dissipation flat portion 151 are each a decagon with ten sides in a plan view. However, the first heat dissipation flat portion and the second heat dissipation flat portion may each be an axisymmetric polygon with four or more sides in a plan view. In this case, first thermally conductive portions are formed on two sides extending from both ends of at least one side of a gap formed by combining the first magnetic core and the second magnetic core, the side from which the lead-out portion of the winding is led out, on four or more sides of the first heat dissipation flat portion. Second thermally conductive portions are formed on two sides extending from both ends of at least one side of a gap formed by combining the first magnetic core and the second magnetic core, the side from which the lead-out portion of the winding is led out, on four or more sides of the second heat dissipation flat portion.

[0049] Furthermore, the present invention is suitably used as a coil component and a switching power supply device equipped with the same, but may also be used as a magnetic component other than a coil component and a device equipped with the magnetic component.

Claims

1. a first magnetic core having a first plate portion; a second magnetic core having a second plate portion; a winding having an air core; a first heat dissipation metal plate having a first heat dissipation plane portion and a first heat conduction portion; a second heat dissipation metal plate having a second heat dissipation plane portion and a second heat conduction portion; Equipped with At least one of the first flat plate portion and the second flat plate portion has a center leg, the center leg is inserted into the hollow core portion, the first magnetic core and the second magnetic core are combined so that the first flat plate portion and the second flat plate portion face each other, the first heat dissipation flat portion and the first flat plate portion and the second heat dissipation flat portion and the second flat plate portion are in close contact with each other, and the first heat conduction portion and the second heat conduction portion are connected, A coil component characterized in that at least one of the first heat conductive portion and the second heat conductive portion has a notch portion, and the other heat conductive portion and the notch portion are solder-connected.

2. The coil component according to claim 1, characterized in that the first heat dissipation flat portion and the second heat dissipation flat portion are each an axisymmetric polygon formed with four or more sides in a planar view, and in the first heat dissipation flat portion, the first heat conduction portion is formed from two sides extending from both ends of one side of a gap formed by combining the first magnetic core and the second magnetic core, on the gap side from which the lead-out portion of the winding is pulled out, and in the second heat dissipation flat portion, the second heat conduction portion is formed from two sides extending from both ends of one side of the gap side.

3. The coil component according to claim 1, characterized in that the first heat dissipation flat portion and the second heat dissipation flat portion are each polygons formed with 10 or more sides in a planar view, and in the first heat dissipation flat portion, the first heat conduction portion is formed from at least two sides of the gap formed by combining the first magnetic core and the second magnetic core, excluding two sides on the gap side from which the lead-out portion of the winding is drawn out, and in the second heat dissipation flat portion, the second heat conduction portion is formed from at least two sides excluding the two sides on the gap side.

4. The coil component according to claim 1 , wherein the first heat dissipation metal plate and the second heat dissipation metal plate have the same shape.

5. In a switching power supply device having a heat dissipation member, A switching power supply device comprising the coil component according to claim 1 , wherein the first heat dissipation flat portion or the second heat dissipation flat portion is thermally connected to the heat dissipation member.

6. 6. A switching power supply device according to claim 5, wherein the heat dissipation member is an aluminum substrate.

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