Magnetic coupling device and flat panel display device including the same

Abstract

A magnetic coupling device is disclosed. The magnetic coupling device includes a core including an upper core and a lower core spaced apart from each other in a first direction, a primary coil and a secondary coil disposed between the upper core and the lower core in a state of being spaced apart from each other in the first direction, and a core connector electrically connected to the upper core and the lower core. By providing the core connector, a discharge phenomenon of a thin magnetic coupling device is prevented.

Description

Technical Field

[0001] The embodiments relate to a magnetic coupling device and a flat panel display device including the magnetic coupling device. Background Technology

[0002] Typically, in order to drive electronic devices, power is required, and in order to supply power to electronic devices, a power supply device, such as a power supply unit (PSU), is used.

[0003] In particular, there is a need for thinner display devices, such as flat-panel TVs, and for larger display devices. Therefore, it is necessary to reduce the thickness of large display devices while increasing their power consumption.

[0004] A transformer is a magnetically coupled device that occupies a larger volume in a power supply unit (PSU) compared to other components. Therefore, to achieve a slimmer profile, methods are often considered to omit thick components from the transformer or to adjust their number. For example, in recent years, the bobbin, in which the primary and secondary coils are wound around the bobbin while fixed to it, has been omitted from the transformer that constitutes the power supply unit of a flat panel display device; or multiple low-capacity, thin transformers have been used.

[0005] However, with the increase in the number of transformers, the transformer area in the power supply unit increases excessively. Furthermore, without the coil, it is difficult to ensure the insulation distance between the primary and secondary coils, thus generating parasitic capacitance between the coils. This parasitic capacitance between the coils can cause undesirable fluctuations in the operating frequency of devices coupled to the transformer. Therefore, it is necessary to suppress parasitic capacitance as much as possible. Additionally, due to the potential difference between the primary and secondary coils, or the potential difference caused by the spacing between the cores, discharge (arc) phenomena may occur, and these discharge phenomena can cause damage to components.

[0006] Therefore, there is a need for a magnetic coupling device that can prevent discharge and reduce parasitic capacitance when it is difficult to ensure the insulation distance between the primary and secondary coils due to the reduction in core thickness, as well as a flat panel display device including such a magnetic coupling device. Summary of the Invention

[0007] The embodiments provide a thin magnetic coupling device capable of preventing discharge phenomena and a flat panel display device including the thin magnetic coupling device.

[0008] The purposes of the embodiments are not limited to those described above, and those skilled in the art will clearly understand other unmentioned purposes based on the following description.

[0009] In one embodiment, the magnetic coupling device includes: a core comprising an upper core and a lower core spaced apart from each other in a first direction; a primary coil and a secondary coil disposed between the upper core and the lower core, spaced apart from each other in the first direction; and a core connector electrically connected to the upper core and the lower core, wherein the spacing distance between the primary coil and the secondary coil in the first direction is less than 0.025 times the sum of the thickness of the upper core in the first direction and the thickness of the lower core in the first direction, and the core connector contacts the outer side surface of the upper core and the outer side surface of the lower core.

[0010] The upper core may include a plurality of first protrusions protruding in a first direction, and the lower core may include a plurality of second protrusions protruding in a first direction.

[0011] Multiple first protrusions and multiple second protrusions can be opposite each other.

[0012] Each of the plurality of first protrusions may extend in a second direction perpendicular to the first direction, and each of the plurality of second protrusions may extend in the second direction.

[0013] The plurality of first protrusions may include two first outer legs spaced apart from each other in a third direction and a first central leg disposed between the two first outer legs, and the plurality of second protrusions may include two second outer legs spaced apart from each other in a third direction and a second central leg disposed between the two second outer legs, wherein the third direction is perpendicular to the first direction and the second direction.

[0014] The third-direction width of each of the first outer legs can be smaller than the third-direction width of the first central leg.

[0015] The spacing between the primary coil and the secondary coil in the first direction can be more than 0.004 times the sum of the thickness of the upper core in the first direction and the thickness of the lower core in the first direction.

[0016] The core may include a first side surface, a second side surface, a third side surface, and a fourth side surface, the first side surface and the second side surface being opposite to each other, the third side surface and the fourth side surface being perpendicular to the first side surface, the third side surface and the fourth side surface being opposite to each other, and each of the primary coil and the secondary coil may be disposed between the third side surface and the fourth side surface and extend to the outside of the core.

[0017] The core connector can extend from the upper core to the lower core on the third side surface.

[0018] The area of ​​the core connector can be 1 / 4 to 1 / 2 of the area of ​​the third side surface.

[0019] The magnetic coupling device may further include an insulating film configured to wrap around the core connector, wherein the insulating film can couple the core connector, the upper core, and the lower core to each other.

[0020] The core connector may not extend to the upper surface of the upper core and the lower surface of the lower core.

[0021] The core connector may contain copper (Cu), the primary coil may include wires wound multiple times in the circumferential direction, and the secondary coil may include a printed circuit board.

[0022] In another embodiment, the magnetic coupling device includes: a core comprising an upper core and a lower core spaced apart from each other in a first direction; a primary coil and a secondary coil disposed between the upper core and the lower core, spaced apart from each other in the first direction; an insulating member disposed between the primary coil and the secondary coil; and a core connector electrically connected to the upper core and the lower core, wherein the distance of the insulating member in the first direction is 0.004 to 0.025 times the sum of the thicknesses of the upper core and the lower core in the first direction.

[0023] The insulating component may include a lower primary insulating layer disposed on the lower surface of the primary coil and an upper secondary insulating layer disposed on the upper surface of the secondary coil.

[0024] The upper core may include: a first upper surface and a first lower surface; a 1-1 side surface and a 1-2 side surface disposed between the first upper surface and the first lower surface, the 1-1 side surface and the 1-2 side surface being opposite to each other; and a plurality of first grooves formed in the first lower surface to be recessed toward the first upper surface, the plurality of first grooves extending from the 1-1 side surface to the 1-2 side surface.

[0025] The lower core may include: a second upper surface and a second lower surface; a 2-1 side surface and a 2-2 side surface disposed between the second upper surface and the second lower surface, the 2-1 side surface and the 2-2 side surface being opposite to each other; and a plurality of second grooves formed in the second upper surface to be recessed toward the second lower surface, the plurality of second grooves extending from the 2-1 side surface to the 2-2 side surface.

[0026] The upper core may include side surfaces 1-3 and 1-4, which are perpendicular to side surfaces 1-1 and 1-2, and are opposite to each other. The lower core may include side surfaces 2-3 and 2-4, which are perpendicular to side surfaces 2-1 and 2-2, and are opposite to each other. Side surfaces 1-3 and 2-3 may be aligned in the same direction, and the core connector may extend from side surface 1-3 to side surface 2-3.

[0027] The area of ​​the core connector can be 1 / 4 to 1 / 2 of the sum of the areas of the 1-3 side surfaces and the 2-3 side surfaces.

[0028] The first lower surface may include a lower surface 1-1, a lower surface 1-2, and a lower surface 1-3 divided by a plurality of first grooves. The lower surface 1-3 is located between the lower surface 1-1 and the lower surface 1-2. The lengths of the lower surfaces 1-1, 1-2, and 1-3 in a second direction from the lower surface 1-1 to the lower surface 1-2 may be equal to each other, and the width of the lower surface 1-3 in a third direction from the lower surface 1-1 to the lower surface 1-2 may be greater than the width of the lower surface 1-1 in a third direction. Attached Figure Description

[0029] The arrangement and embodiments can be described in detail with reference to the following figures, wherein the same reference numerals refer to the same elements, in the figures:

[0030] Figure 1 This is a perspective view of the transformer according to an embodiment;

[0031] Figure 2A and Figure 2B This is an exploded perspective view of the transformer according to an embodiment;

[0032] Figure 3A and Figure 3B This is a diagram illustrating the discharge phenomenon of the transformer according to the comparative example;

[0033] Figure 4 This is a diagram illustrating the effect of the transformer according to an embodiment; and

[0034] Figure 5 This is a side view of an example of the structure of a transformer according to another embodiment. Detailed Implementation

[0035] This disclosure can be modified in various ways and can have various embodiments, wherein specific embodiments will be described with reference to the accompanying drawings. However, this disclosure is not limited to the specific embodiments, and it should be understood that this disclosure includes all modifications, equivalents, or substitutions included within the spirit and scope of this disclosure.

[0036] Although ordinal terms (e.g., "first" and "second") may be used herein to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first element may be referred to as a second element without departing from the scope of this disclosure, and similarly, a second element may be referred to as a first element. The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should be understood that when a component is described as "connected to" or "coupled to" another component, it can be directly connected to or coupled to the other component, or there can be intermediate components. Conversely, it should be understood that when a component is described as "directly connected to" or "directly coupled to" another component, there are no intermediate components.

[0038] In the following description of the embodiments, it will be understood that when an element such as a layer (film), region, pattern, or structure is described as being "on" or "under" another element such as a substrate, layer (film), region, pad, or pattern, it may be formed "directly" on or under the other element, or it may be formed "indirectly" such that intermediate elements are also present. Terms such as "on" or "under" will be described based on the accompanying drawings. Additionally, in the drawings, for ease of description and clarity, the thickness or size of the layer (film), region, pattern, or structure may be varied, and therefore its dimensions may not perfectly reflect its actual size.

[0039] The terminology used in this application is provided only to describe particular embodiments and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form. It should be understood throughout this application that the terms “comprising,” “having,” etc., specify the presence of the stated features, quantities, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, or combinations thereof.

[0040] Unless otherwise defined, all terms (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Common terms, such as those defined in typical dictionaries, shall be interpreted as consistent with the meaning in the context of the relevant art and shall not be interpreted in an ideal or overly formal sense unless explicitly defined to the contrary.

[0041] In the following description, a magnetic coupling device according to an embodiment will be described with reference to the accompanying drawings. For ease of description, the magnetic coupling device is assumed to be a transformer; however, this is illustrative and the embodiments are not limited thereto. For example, in addition to a transformer, the magnetic coupling device according to the embodiment may also include magnetic elements such as inductors.

[0042] Figure 1 This is a perspective view of a transformer according to an embodiment. Figure 2A and Figure 2B This is an exploded perspective view of the transformer according to an embodiment.

[0043] Comprehensive reference Figures 1 to 2BThe transformer 100 according to the embodiment may include a core 110, a primary-side coil 120, a secondary-side coil 130, core connectors 141 and 142, and terminal units TM1 and TM2. These components will be described in detail below.

[0044] The core 110 can have the properties of a magnetic circuit and thus can be used as a magnetic flux path. The core may include an upper core 111 located on the upper side and a lower core 112 located on the lower side. Cores 111 and 112 may have a vertically symmetrical or asymmetrical shape. Core 110 may include a magnetic material, such as iron or ferrite. However, the embodiments are not limited thereto. It is well known that each of the upper core 111 and the lower core 112 is an "E"-shaped core having a plurality of protrusions projecting from a flat body along a first direction (i.e., a first axial direction). For example, the upper core 111 may include a plurality of first protrusions OL1 and CL1 projecting in the first direction, and the lower core 112 may include a plurality of second protrusions OL2 and CL2 projecting in the first direction. Here, the plurality of first protrusions OL1 and CL1 and the plurality of second protrusions OL2 and CL2 may be opposite each other. Each of the plurality of first protrusions OL1 and CL1 and the plurality of second protrusions OL2 and CL2 may extend in a second direction (i.e., a second axial direction) intersecting (e.g., perpendicular to) the first direction.

[0045] The plurality of first protrusions OL1 and CL1 may include two first outer legs OL1 spaced apart from each other in a third direction (i.e., the third axis direction) intersecting (e.g., perpendicular to) the first and second directions, and a first central leg CL1 disposed between the two first outer legs OL1. Additionally, the plurality of second protrusions OL2 and CL2 may include two second outer legs OL2 spaced apart from each other in a third direction, and a second central leg CL2 disposed between the two second outer legs OL2. Here, the width of each of the two first outer legs OL1 in the third direction may be smaller than the width of the first central leg CL1 in the third direction.

[0046] The upper core 111 may include: a first upper surface corresponding to the upper surface of the core 110; a first lower surface corresponding to the lower surface of the core 110; a 1-1 side surface S1-1; a 1-2 side surface opposite to the 1-1 side surface S1-1; a 1-3 side surface S1-3 perpendicular to the 1-1 side surface S1-1 and the 1-2 side surface; and a 1-4 side surface opposite to the 1-3 side surface S1-3.

[0047] Additionally, the lower core 112 may include: a second upper surface corresponding to the upper surface of the core 110; a second lower surface corresponding to the lower surface of the core 110; a 2-1 side surface S2-1; a 2-2 side surface opposite to the 2-1 side surface S2-1; a 2-3 side surface S2-3 perpendicular to the 2-1 side surface S2-1 and the 2-2 side surface; and a 2-4 side surface opposite to the 2-3 side surface S2-3.

[0048] The 1-1 side surface S1-1 and the 2-1 side surface S2-1, which are aligned in the same direction, correspond to the first side surface of the core 110, and the 1-2 side surface and the 2-2 side surface correspond to the second side surface of the core 110. Furthermore, the 1-3 side surface S1-3 and the 2-3 side surface S2-3, which are aligned in the same direction, correspond to the third side surface of the core 110, and the 1-4 side surface and the 2-4 side surface correspond to the fourth side surface of the core 110.

[0049] The upper core 111 may include a plurality of first grooves RC1 formed in the first lower surface to be recessed toward the first upper surface, the plurality of first grooves RC1 extending from the 1-1 side surface S1-1 to the 1-2 side surface.

[0050] Additionally, the lower core 112 may include a plurality of second grooves RC2 formed in the second upper surface to recess toward the second lower surface, the plurality of second grooves RC2 extending from the 2-1 side surface S2-1 to the 2-2 side surface.

[0051] Each of the plurality of first grooves RC1 and the plurality of second grooves RC2 defines two through holes, and these two through holes can be used as receiving holes configured to receive a portion of the primary side coil portion 120 and a portion of the secondary side coil portion 130.

[0052] On the other hand, the plurality of first grooves RC1 divide the first lower surface of the upper core 111 into a lower surface 1-1, a lower surface 1-2, and a lower surface 1-3 located between the lower surfaces 1-1 and 1-2. Here, each of the lower surfaces 1-1, 1-2, and 1-3 can correspond to the lower surface of each of the plurality of first grooves RC1. The lengths of the lower surfaces 1-1, 1-2, and 1-3 in the second direction can be equal to each other, and the width of the lower surface 1-3 in the third direction can be greater than the width of the lower surface 1-1 in the third direction.

[0053] The upper core 111 and the lower core 112 are coupled to each other in the form that the outer legs OL1 and OL2 are opposite each other and the central legs CL1 and CL2 are opposite each other, with the middle spacer SP located between the opposing outer legs and between the opposing central legs, i.e., in the gap between them. Each spacer SP may include an insulating material with a specified thickness or a thermally conductive material that can easily perform heat transfer and thus transfer heat from the core to the outside.

[0054] The gap, i.e., the distance in the first direction between the upper core 111 and the lower core 112, can be from 100 μm to 200 μm. When the gap is less than 100 μm, it is difficult to effectively dissipate the heat generated in the core 110 to the outside. When the gap is greater than 200 μm, the coupling force between the upper core 111 and the lower core 112 and / or the coupling force between the primary side coil portion 120 and the secondary side coil portion 130 may be reduced.

[0055] As the gaps between the opposing central legs and the opposing outer legs are adjusted, the inductance of the core 110 can be controlled, and the total heat generated from the transformer 100 can be reduced as heat within the core is dissipated to the outside. The first-direction thickness T1+T2 of each of the upper core 111 and the lower core 112 can be 4 mm to 5 mm, preferably 4.6 mm to 4.8 mm. The first-direction thickness T1+T2 of each of the upper core 111 and the lower core 112 can define the total thickness of the transformer, and a thinner transformer can be achieved that satisfies the magnetic coupling characteristics only within the aforementioned thickness range. However, since this thickness range is based on current technological limitations of magnetic coupling devices for thinner designs, the aforementioned thickness can be reduced or increased to satisfy greater magnetic coupling characteristics.

[0056] The ratio of the distance in the first direction between the upper core 111 and the lower core 112 to the sum of the thicknesses of the upper core 111 and the lower core 112 in the first direction (i.e., 2*(T1+T2)) can be 0.01 to 0.025 or less. When this ratio is satisfied, a structure can be provided that can ensure the coupling force between the primary side coil portion 120 and the secondary side coil portion 130 while easily dissipating the heat generated in the core portion 110 to the outside of the core portion, and the magnetic coupling device can be made thinner.

[0057] The primary coil portion 120 may include a primary coil 122 and an upper primary insulating layer 121 and a lower primary insulating layer 123 respectively disposed on the upper and lower portions of the primary coil 122. Specifically, the upper primary insulating layer 121 may contribute to the insulation between the upper core 111 and the primary coil 122, and the lower primary insulating layer 123 may contribute to the insulation between the upper core 111 and the secondary coil portion 130. The upper primary insulating layer 121 and the lower primary insulating layer 123 may be made of the same material or may be made of different materials. The upper primary insulating layer 121 and the lower primary insulating layer 123 can be integrally formed so as to not only wrap the upper and lower surfaces of the primary coil 122, but also the side surfaces of the primary coil 122, thereby shielding the primary coil 122. Alternatively, the planar area of ​​each of the upper primary insulating layer 121 and the lower primary insulating layer 123 can be formed to be larger than the planar area of ​​the primary coil 122, such that the upper primary insulating layer 121 and the lower primary insulating layer 123 are coupled to each other outside the primary coil 122. Therefore, the insulation characteristics between the primary coil 122 and the core 110, as well as the insulation characteristics between the primary coil 122 and the secondary side coil portion 130, can be ensured.

[0058] The thickness of each of the upper primary insulation layer 121 and the lower primary insulation layer 123 can be from 50 μm to 75 μm. When the thickness is less than 50 μm, it is difficult to ensure insulation properties. When the thickness is greater than 75 μm, the effect of heat dissipation through the gap between the upper core 111 and the lower core 112 may be reduced. Here, the sum of the thickness of the primary-side coil portion 120 and the secondary-side coil portion 130 must be less than the thickness in the first direction of each receiving hole (i.e., two through holes extending in the second direction) configured to accommodate the coil portions 120 and 130, such that the primary-side coil portion 120 and the secondary-side coil portion 130 are accommodated in the receiving holes when the upper core 111 and the lower core 112 are coupled to each other. Here, assuming that the upper core 111 and the lower core 112 are symmetrical in shape and that the height T2 of the central support leg and the outer support leg of each core are equal to each other, the height of each receiving hole can correspond to the sum of the first direction thickness T2 of each of the central support leg and the outer support leg of the upper core 111, the first direction thickness T2 of each of the central support leg and the outer support leg of the lower core 112, and the first direction thickness of each spacer SP (i.e., the thickness of 2*T2+SP).

[0059] However, as long as the heat dissipation effect is achieved while the coil is housed in the receiving hole, the thickness of the upper primary insulation layer 121 and the lower primary insulation layer 123 can be less than 50 μm or greater than 75 μm.

[0060] The primary coil 122 can be a multi-winding formed by winding a rigid metal conductor, such as copper wire, multiple times in a planar helical manner in the circumferential direction. However, the embodiments are not limited to this. For example, the primary coil 122 can be a metal plate etched to form multiple turns, or it can be formed into the shape of a plate on which such a metal plate is printed.

[0061] Each of the upper primary insulating layer 121 and the lower primary insulating layer 123 may be in the shape of a thin film having a specified thickness and may include a highly insulating component such as ketone or polyimide. However, the embodiments are not limited thereto. For example, each of the upper primary insulating layer 121 and the lower primary insulating layer 123 may be formed in the shape of an insulating coating.

[0062] The secondary coil portion 130 may include a secondary coil 132 and an upper secondary insulation layer 131 and a lower secondary insulation layer 133 respectively disposed on the upper and lower portions of the secondary coil 132. Specifically, the upper secondary insulation layer 131 may contribute to the insulation between the primary coil portion 120 and the secondary coil 132, and the lower secondary insulation layer 133 may contribute to the insulation between the secondary coil 132 and the lower core 112.

[0063] The secondary coil 132 may include a conductive plate forming a single turn, and multiple conductive plates, such as two or more, may be provided. For example, the secondary coil 132 may be formed in the shape of a printed circuit board (PCB) with conductive plates provided on opposite surfaces of the PCB, or in the shape of PCBs stacked in a first direction (i.e., the first axial direction) with conductive plates provided on one surface of each PCB. However, the embodiments are not limited thereto. When using a PCB with conductive plates provided on its opposite surfaces, the conductive plates provided on each surface may have a planar shape that is horizontally symmetrical to each other in a third direction (i.e., the third axial direction). However, the embodiments are not limited thereto.

[0064] The upper secondary insulating layer 131 and the lower secondary insulating layer 133 can be made of the same material as the upper primary insulating layer 121 and the lower primary insulating layer 123. However, the embodiments are not limited to this. Additionally, similar to the upper primary insulating layer 121 and the lower primary insulating layer 123, the thickness of the upper secondary insulating layer 131 and the lower secondary insulating layer 133 can be 50 μm to 60 μm. However, the embodiments are not limited to this.

[0065] On the other hand, the insulation distance in the first direction between the primary coil 122 and the secondary coil 132 can be the spacing distance between the primary coil 122 and the secondary coil 132, and the insulating member can be disposed within this spacing distance. Furthermore, when the thickness of the insulating member is equal to the spacing distance, the spacing distance can correspond to the thickness of the insulating member in the first direction. Here, the insulating member between the primary coil 122 and the secondary coil 132 can be a lower primary insulating layer 123 and an upper secondary insulating layer 131. The insulation distance affects the parasitic capacitance between the primary coil 122 and the secondary coil 132.

[0066] Preferably, the ratio of the sum of the lower primary insulation layer 123 and the upper secondary insulation layer 131 to the sum of the thicknesses of the upper core 111 and the lower core 112 (e.g., 2*(T1+T2)) can be from 0.004 to 0.025. More preferably, this ratio can be from 0.01 to 0.015. Within the above ratios, a thin magnetic coupling device can be manufactured while preventing electrical short circuits or current leakage between the primary coil 122 and the secondary coil 132.

[0067] The primary coil portion 120 and the secondary coil portion 130 can be aligned with each other based on the central support leg in the first direction (i.e., the first axial direction) of the core portion 110. For this purpose, each of the primary coil portion 120 and the secondary coil portion 130 can have a hollow hole corresponding to the planar shape of the central support leg of the core portion 110, such that the central support leg is disposed in the hollow hole.

[0068] Each of the primary coil 122 and the secondary coil 132 may be disposed between the third and fourth side surfaces of the core 110 and extend to the outside of the core 110.

[0069] Core connectors 141 and 142 may be disposed on the outer side surface of the upper core 111 and the outer side surface of the lower core 112 to physically couple or electrically connect the upper core 111 and the lower core 112 to each other. For example, the upper core 111 and the lower core 112 may be electrically short-circuited to each other via core connectors 141 and 142. For short-circuiting, at least a portion of each of core connectors 141 and 142 may be in contact with the upper core 111 (i.e., electrically connected), and at least a portion of the remaining portion of each of core connectors 141 and 142 may be in contact with the lower core 112.

[0070] That is, each of the core connectors 141 and 142 can be configured to extend from the side surface of the upper core 111 to the side surface of the lower core 112. For example, each of the core connectors 141 and 142 can be configured such that at least one of the first to fourth side surfaces of the upper core 111 and at least one of the first to fourth side surfaces of the lower core 112 are electrically connected to each other. More specifically, the core connector 141 can extend from the 1-3 side surface S1-3 to the 2-3 side surface S2-3. That is, the core connector 141 can extend from the upper core 111 to the lower core 112 on the third side surface.

[0071] To prevent an increase in the overall thickness of the magnetic coupling device, each of the core connectors 141 and 142 may not extend to the upper surface of the upper core 111 and / or the lower surface of the lower core 112. Therefore, the area of ​​each of the core connectors 141 and 142 may be 1 / 4 to 1 / 2 of the sum of the areas of the 1-3 side surfaces S1-3 of the upper core 111 and the 2-3 side surfaces S2-3 of the lower core 112 (i.e., the area of ​​the third side surface). However, the above area ratio is illustrative. Embodiments are not limited to this, as long as the coupling force between the upper core 111 and the lower core 112 can be ensured, parasitic capacitance reduced, and discharge phenomena prevented.

[0072] Preferably, the height of the core connectors 141 and 142 in the first direction can be less than the sum of the thicknesses of the upper core 111 and the lower core 112.

[0073] Additionally, each of core connectors 141 and 142 may include conductive material for short-circuiting between the upper core 111 and the lower core 112, and may have a thin-film shape for thinning the overall transformer. However, the embodiments are not limited thereto. As an example, each of core connectors 141 and 142 may be copper foil or wire having a circular or polygonal cross-sectional shape. As another example, each of core connectors 141 and 142 may be copper foil having a polygonal or circular planar shape instead of a quadrilateral planar shape.

[0074] Figures 1 to 2BThe diagram shows core connectors 141 and 142 having quadrilateral planar shapes disposed on opposite side surfaces of core 110; however, this is illustrative. The shape and position of core connectors 141 and 142 are not particularly limited, as long as the core connectors can electrically connect upper core 111 and lower core 112 to each other. As an example, one of core connectors 141 and 142 may be omitted. As another example, at least one of spacers SP disposed between opposite central legs and opposite outer legs of core 110 may be used instead of core connectors 141 and 142. In this case, each of the core connectors replaced by the spacer SP for short-circuiting between upper core 111 and lower core 112 may be made of anisotropic conductive film (ACF) or copper (Cu) foil.

[0075] Terminal units TM1 and TM2 can be coupled to the board of secondary coil 132 constituting secondary side coil section 130, and can perform the function of fixing transformer 100 to the board of power supply unit (PSU) (not shown), and serve as an electrical connection path between each of coil sections 120 and 130 and the board of power supply unit (PSU) (not shown).

[0076] More specifically, terminal units TM1 and TM2 may include primary coil side terminals TM1_1 and TM1_2 and secondary coil side terminals TM2_1, TM2_2, and TM2_3. Primary coil side terminals TM1_1 and TM1_2 may be electrically connected to the opposite ends of the wires constituting the primary coil 122. Additionally, secondary coil side terminals TM2_1, TM2_2, and TM2_3 may be connected to the conductive plates constituting the secondary coil 132. For example, secondary coil side terminals TM2_1 and TM2_3 located at the opposite edges may correspond to signal terminals, while secondary coil side terminal TM2_2 located at the center may correspond to a ground terminal. Furthermore, the secondary coil side terminal TM2_2 located at the center can electrically connect multiple metal plates connected to any one of the secondary coil side terminals TM2_1 and TM2_3 located at the opposite edges, thereby realizing a so-called center tap structure.

[0077] On the other hand, although Figures 1 to 2B Not shown, but the transformer according to the embodiment may further include an insulating film configured to wrap the core connectors 141 and 142 while coupling the core connectors 141 and 142, the upper core 111 and the lower core 112 to each other.

[0078] In the following text, reference will be made to Figure 3A and Figure 3B The principle of the discharge phenomenon occurring in the transformer 100' according to the comparative example will be described with reference to... Figure 4The effect of preventing discharge phenomena in the transformer according to the embodiment is described.

[0079] Figure 3A and Figure 3B This is a diagram illustrating the discharge phenomenon of a transformer according to a comparative example. Figure 4 This is a diagram illustrating the effect of a transformer according to an embodiment.

[0080] According to Figures 1 to 2B Compared to the transformer 100 of the illustrated embodiment, in accordance with Figure 3A The transformer 100' in the comparative example shown does not have core connectors 141 and 142. Additionally, Figure 3B It is based on Figure 3A The circuit diagram of transformer 100' in the comparative example is shown.

[0081] Let's refer to each other. Figure 3A and 3B When a thin structure is adopted, the physical insulation distance in the first direction between the primary side coil portion 120' and the secondary side coil portion 130' may be insufficient. Therefore, even when multiple insulation layers are provided, discharge may occur due to the potential difference between parasitic capacitance components C1, C2, and C12. Specifically, in the transformer 100' according to the comparative example, parasitic capacitance component C1 exists between the upper core 111' and the primary side coil portion 120', parasitic capacitance component C12 exists between the primary side coil portion 120' and the secondary side coil portion 130', and parasitic capacitance component C2 exists between the secondary side coil portion 130' and the lower core 112'. At this time, it is assumed that the voltage of parasitic capacitance component C1 applied between the upper core 111' and the primary side coil portion 120' is V_C1, and the voltage of parasitic capacitance component C2 applied between the secondary side coil portion 130' and the lower core 112' is V_C2. When transformer 100' is operating, the difference between the voltage induced in the secondary winding section 130' and the voltage applied to the primary winding section 120', i.e., the potential difference corresponding to the value obtained by multiplying the voltage induced in the secondary winding section 130' by (the winding ratio of each winding section - 1), is generated between V_C1 and V_C2. As a result, a discharge phenomenon occurs due to the large potential difference between V_C1 and V_C2.

[0082] In contrast, in the transformer 100 according to the embodiment, such as Figure 4 As shown, since the upper core 111 and the lower core 112 are short-circuited to each other due to the core connectors 141 and 142, no voltage difference is generated between V_C1 and V_C2, thus preventing discharge.

[0083] As described above, in the transformer 100 according to the embodiment, the discharge phenomenon caused by the inherent insufficiency of the insulation distance due to the adaptation to the thin structure is solved by short-circuiting between the upper core 111 and the lower core 112. Another embodiment proposes a method that, in addition to preventing the discharge phenomenon, also reduces the parasitic capacitance itself by grounding the core connectors 141 and 142 that short-circuit the upper core 111 and the lower core 112 to each other.

[0084] As mentioned earlier, parasitic capacitance components C1, C2, and C12 are generated in the coil sections adjacent to each core. However, when the parasitic capacitance present in the transformer increases, the following abnormal phenomena may occur.

[0085] When outputting under light load conditions (e.g., a low-power image on a flat panel display screen, specifically an image with predominantly black), the feedback circuit configured to control the output voltage of the power supply unit (PSU) may malfunction, potentially causing an abnormal increase in the output voltage. In other words, under normal operation, the primary current of the transformer has a sinusoidal waveform; however, when the feedback circuit malfunctions, current distortion occurs, leading to increased harmonics, which adversely affects EMI performance. Therefore, methods to reduce parasitic capacitance components are needed.

[0086] In the event that the upper core 111 and the lower core 112 are short-circuited to each other, such as Figure 4 As shown, the total parasitic capacitance component Ctotal of transformer 100 is as follows.

[0087] Ctotal = C1² + (C1 * C2) / (C1 + C2)

[0088] Here, C12 is a component belonging to the transformer design, and the values ​​of C1 and C2 can be controlled by grounding core connectors 141 and 142. The experimentally verified changes in the parasitic capacitance components are shown in Table 1 below.

[0089] [Table 1]

[0090] Before grounding 100 110 145 162.5 After grounding 100 10 30 107.5

[0091] A grounding method can be used by electrically connecting a wire to at least one of the core connectors 141 and 142 to connect to the grounding circuit of the power supply unit (PSU). However, the embodiments are not limited to this. For example, the wire connected to at least one of the core connectors 141 and 142 can first be connected to a separate terminal (not shown) provided on the plate constituting the secondary side coil section 130, and then can be connected to the grounding circuit of the power supply unit (PSU) via the terminal.

[0092] On the other hand, in another embodiment, the core connector may be spaced apart from the side surface of the core 110, which will refer to Figure 5 Describe it.

[0093] Figure 5 This is a side view of an example of the structure of a transformer according to another embodiment. For clarity, from... Figure 5 The primary side coil section 120 and the secondary side coil section 130 are omitted.

[0094] refer to Figure 5 In a transformer according to another embodiment, the upper core 111 and the lower core 112 are arranged to be spaced apart from each other in a first direction with the spacer SP inserted between them. Insulating units 151 and 152 may be respectively disposed on the third and fourth side surfaces of the cores 111 and 112 facing each other in a third direction (i.e., along a third axis), and core connectors 141' and 142' may each extend from the upper surface of the upper core 111 to the lower surface of the lower core 112 to wrap around the outer edges of the insulating units 151 and 152. For example, each of the core connectors 141' and 142' may extend outward from the upper surface of the upper core 111 in a third direction, may be bent at the outer edge of the upper surface of a corresponding insulating unit in the insulating units 151 and 152, may extend along the outer surface of a corresponding insulating unit in the insulating units 151 and 152, may be bent at the outer edge of the lower surface of a corresponding insulating unit in the insulating units 151 and 152, and may extend in a third direction to the lower surface of the lower core 112.

[0095] Each of the insulating units 151 and 152 may include a polymer resin film, paper, or an air gap; however, this is illustrative and the embodiments are not limited thereto.

[0096] In the above structure, each of the core connectors 141' and 142' can be spaced apart from the side surface of the core by the thickness D of a corresponding insulating unit in the insulating units 151 and 152 in a third-party upward direction.

[0097] When the conductor is positioned on the side surface of the core, the magnetic flux generated in the core can contact the conductor, potentially inducing eddy currents. Eddy currents can increase the AC resistance and decrease the Q value of the magnetic coupling device, and may also increase the heat generated within the magnetic coupling device. However, since the core connectors 141' and 142' are spaced apart from the core, the effects of eddy currents can be reduced. As the effects of eddy currents decrease, the Q value increases, the heat generated in the magnetic coupling device decreases, and the power consumption required to drive another coupling device, such as a PSU, decreases.

[0098] In addition to the effects of eddy currents, the parasitic capacitance generated between the core and the core connectors 141' and 142' can also be reduced because the core connectors 141' and 142' are spaced apart from the core.

[0099] Table 2 below shows the effect of the spacing distance D between each of the core connectors 141' and 142' and the side surface of the core.

[0100] [Table 2]

[0101]

[0102] Referring to Table 2, it can be seen that as the interval distance D increases, the Q value increases while the resistance Rs and capacitance Cs decrease.

[0103] The aforementioned magnetic coupling device may include a filter or transformer and may have signal coupling, filtering, and voltage and / or power conversion functions. Because magnetic coupling devices can be made thinner while reducing parasitic capacitance and preventing discharge, they can meet the demand for thin electronic products. For example, when magnetic coupling devices are applied to mobile devices, household appliances such as televisions, or vehicle components, the thickness of the components can be reduced, thereby ensuring the characteristics of a lightweight and thin product.

[0104] It is evident from the above description that, in the magnetic coupling device according to the embodiments and the flat panel display device including the magnetic coupling device, by providing a core connector configured to short-circuit one core and another core constituting the core with each other, the difference between the parasitic voltage between one core and the primary coil and the parasitic capacitance between the other core and the secondary coil can be resolved. Therefore, fluctuations in the operating frequency of the circuit using the magnetic coupling device can be resolved.

[0105] In addition, it can prevent discharge phenomena caused by voltage differences between cores that may occur when it is necessary to ensure the spacing between cores to reduce inductance or to perform heat dissipation, or prevent discharge phenomena caused by placing the primary coil and secondary coil adjacent to each other for the purpose of thinning.

[0106] It should be noted that the effects of the embodiments are not limited to those described above, and those skilled in the art will clearly understand from the above description other effects not mentioned.

[0107] Although embodiments have been described with reference to several illustrative examples, it should be understood that those skilled in the art can devise many other variations and embodiments falling within the spirit and scope of the principles of this disclosure. More specifically, various changes and variations in the components and / or arrangements of the subject matter arrangement are possible within the scope of this disclosure, the drawings, and the appended claims. In addition to changes and variations in the components and / or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

1. A magnetic coupling device, comprising: A first core and a second core, the first core and the second core being spaced apart from each other in a first direction, with a gap formed between the first core and the second core; A spacer disposed in the gap and comprising an insulating material; A first coil and a second coil, the first coil and the second coil being disposed between the first core and the second core and spaced apart from each other in the first direction; as well as A core connector, wherein the core connector is disposed on the outside of the first core and the second core. Wherein, the interval distance in the first direction between the first coil and the second coil is equal to or less than a predetermined value, and the predetermined value is the distance at which discharge occurs due to the parasitic capacitance between two adjacent elements of the first core, the second core, the first coil, and the second coil. The core connector contacts the outer surface of the first core and the outer surface of the second core and is electrically connected to the first core and the second core. The core connector does not extend to at least one of the upper surface of the first core and the lower surface of the second core.

2. The magnetic coupling device according to claim 1, in, The first core includes a plurality of first protrusions projecting in the first direction, and The second core includes a plurality of second protrusions projecting in the first direction.

3. The magnetic coupling device according to claim 2, wherein, The plurality of first protrusions and the plurality of second protrusions are opposite to each other.

4. The magnetic coupling device according to claim 3, in, Each of the plurality of first protrusions extends in a second direction, the second direction being perpendicular to the first direction, and Each of the plurality of second protrusions extends in the second direction.

5. The magnetic coupling device according to claim 4, wherein, The plurality of first protrusions include two first outer legs spaced apart from each other in a third direction, and a first central leg disposed between the two first outer legs. The plurality of second protrusions include two second outer legs spaced apart from each other in the third direction, and a second central leg disposed between the two second outer legs. The third direction is perpendicular to both the first direction and the second direction.

6. The magnetic coupling device according to claim 5, wherein, The third-direction width of each of the first outer legs is smaller than the third-direction width of the first central leg.

7. The magnetic coupling device according to claim 1, wherein, The spacing between the first coil and the second coil in the first direction satisfies at least one of the first condition and the second condition. The first condition is that the spacing distance is less than 0.025 times the sum of the thickness of the first core in the first direction and the thickness of the second core in the first direction, and the second condition is that the spacing distance is more than 0.004 times the sum of the thickness of the first core in the first direction and the thickness of the second core in the first direction.

8. The magnetic coupling device according to claim 7, wherein, Each of the first core and the second core includes a first side surface, a second side surface, a third side surface, and a fourth side surface. The first side surface and the second side surface are opposite to each other, and the third side surface and the fourth side surface are perpendicular to the first side surface. The first coil and the second coil extend from the inside of the third side surface and the fourth side surface of the first core outward.

9. The magnetic coupling device according to claim 8, wherein, The core connector extends from the third side surface of the first core to the third side surface of the second core.

10. The magnetic coupling device according to claim 9, wherein, The area of ​​the core connector is 1 / 4 to 1 / 2 times the area of ​​the third side surface.

11. The magnetic coupling device according to claim 1, further comprising: An insulating film covering the outer surface of the core connector. The insulating film couples the core connector, the first core, and the second core to each other.

12. The magnetic coupling device according to claim 11, wherein, The core connector does not extend to the upper surface of the first core and the lower surface of the second core.

13. The magnetic coupling device according to claim 12, in, The core connector contains copper (Cu). The first coil comprises a wire wound multiple times in the circumferential direction, and The second coil includes a printed circuit board.

14. A magnetic coupling device, comprising: A first core and a second core, the first core and the second core being spaced apart from each other in a first direction, with a gap formed between the first core and the second core; A spacer disposed in the gap and comprising an insulating material; A first coil and a second coil, the first coil and the second coil being disposed between the first core and the second core and spaced apart from each other in the first direction; An insulating component is disposed between the first coil and the second coil; as well as A core connector, wherein the core connector is disposed on the outside of the first core and the second core. Wherein, the interval distance in the first direction between the first coil and the second coil is equal to or less than a predetermined value, and the predetermined value is the distance at which discharge occurs due to the parasitic capacitance between two adjacent elements of the first core, the second core, the first coil, and the second coil. The core connector is electrically connected to the first core and the second core, and does not extend to at least one of the first upper surface of the first core and the second lower surface of the second core.

15. The magnetic coupling device according to claim 14, in, The insulating component includes a first insulating layer and a second insulating layer. The first insulating layer is disposed on the lower surface of the first coil. The second insulating layer is disposed on the upper surface of the second coil. The thickness of the insulating member in the first direction is 0.004 to 0.025 times the sum of the thickness of the first core in the first direction and the thickness of the second core in the first direction.

16. The magnetic coupling device according to claim 14, in, The first core includes a first upper surface, a first lower surface opposite to the first upper surface, and a first side surface disposed between the first upper surface and the first lower surface. Among them, a plurality of first grooves are recessed from the first lower surface of the first core toward the first upper surface of the first core. The first side surface includes a 1-1 side surface and a 1-2 side surface opposite to the 1-1 side surface. The plurality of first grooves extend from the 1-1 side surface to the 1-2 side surface.

17. The magnetic coupling device according to claim 16, in, The second core includes a second upper surface, a second lower surface opposite to the second upper surface, and a second side surface disposed between the second upper surface and the second lower surface. Among them, a plurality of second grooves are recessed from the second upper surface of the second core toward the second lower surface of the second core. The second side surface includes a 2-1 side surface and a 2-2 side surface opposite to the 2-1 side surface. The plurality of second grooves extend from the 2-1 side surface to the 2-2 side surface.

18. The magnetic coupling device according to claim 17, in, The first core includes side surfaces 1-3 and 1-4, which are perpendicular to side surfaces 1-1 and 1-2, and are opposite to each other. The second core includes a 2-3 side surface and a 2-4 side surface, wherein the 2-3 side surface and the 2-4 side surface are perpendicular to the 2-1 side surface and the 2-2 side surface, and the 2-3 side surface and the 2-4 side surface are opposite to each other. Wherein, the 1-3 side surfaces and the 2-3 side surfaces are aligned in the same direction, and The core connector extends from the 1-3 side surface to the 2-3 side surface.

19. The magnetic coupling device according to claim 18, wherein, The area of ​​the core connector is 1 / 4 to 1 / 2 times the sum of the areas of the 1-3 side surfaces and the 2-3 side surfaces.

20. The magnetic coupling device according to claim 17, in, The first lower surface includes a lower surface 1-1, a lower surface 1-2, and a lower surface 1-3, which are divided by the plurality of first grooves. The lower surface 1-3 is located between the lower surface 1-1 and the lower surface 1-2. Wherein, the lengths of the lower surfaces 1-1, 1-2, and 1-3 in the second direction from the side surface 1-1 to the side surface 1-2 are equal to each other, and Wherein, the width of the lower surface of 1-3 in the third direction from the lower surface of 1-1 to the lower surface of 1-2 is greater than the width of the lower surface of 1-1 in the third direction.

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