Transformer

Abstract

A transformer according to an embodiment comprises: a core part including upper cores and lower cores disposed in a first direction facing the upper cores; and a coil part at least partially disposed between the upper cores and the lower cores, wherein the upper cores include protruding portions protruding in the first direction, and the lower cores include recessed portions coupled to the protruding portions.

Description

Transformers

[0001] The embodiment relates to a transformer.

[0002] The power supply of electronic devices is equipped with various coil components such as transformers and line filters.

[0003] Transformers can be incorporated into electronic devices for a variety of purposes. For example, they can be used to transfer energy from one circuit to another. They can also be used to change the voltage level, either by stepping up or stepping down. Furthermore, transformers, which only have inductive coupling between their primary and secondary windings and thus no direct DC path, can be used to block DC and pass AC, or to provide insulation between two circuits.

[0004] These transformers include a lower core and an upper core, and the desired inductance can be achieved by adjusting the thickness of the gap paper placed in the gap between the cores. However, various problems arise, such as the need to secure the gap paper with adhesive, and research is currently underway to address these issues.

[0005] The embodiment provides a transformer having excellent heat dissipation characteristics and efficiency.

[0006] A transformer according to one embodiment includes a core portion including an upper core and a lower core arranged in a first direction opposite to the upper core; a coil portion at least partially arranged between the upper core and the lower core; the upper core may include a ferrous portion protruding in the first direction, and the lower core may include a ridge portion coupled to the ferrous portion.

[0007] For example, the bottom surface of the above-mentioned portion may face the surface of the iron portion that faces the bottom surface in the first direction with a gap therebetween.

[0008] For example, a step portion may be arranged on the inner edge of the above-mentioned portion, and the iron portion may include a catch supported by the step portion.

[0009] For example, the step portion and the catch can be arranged in direct contact.

[0010] For example, the lower core may communicate the inner space of the yoke with the outer space, and may include a side groove formed on an outer edge of the edge defining the yoke.

[0011] For example, the size of the side groove may be less than or equal to 41% of the total length of the outer edge.

[0012] For example, the upper core may include first and second upper cores that are adjacent to each other in a second direction intersecting the first direction, and the lower core may include first and second lower cores that are adjacent to each other in the second direction and opposite the first and second upper cores, respectively.

[0013] For example, the first upper core may include a first outer portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and including a first ferrule protruding in the first direction; and a first inner portion disposed on the other side of the second direction, extending in the third direction, and including a second ferrule protruding in the first direction; and the first lower core may include a first concave portion facing the first outer portion in the first direction, extending in the third direction to accommodate the first ferrule; and a second concave portion facing the first inner portion in the first direction, extending in the third direction to accommodate the second ferrule; the concave portion may include the first and second ferrules, and the concave portion may include the first and second concave portions.

[0014] For example, the second upper core may include a second outer portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and including a third protrusion protruding in the first direction; and a second inner portion disposed on the other side of the second direction, extending in the third direction, and including a fourth protrusion protruding in the first direction; and the second lower core may include a third portion facing the second outer portion in the first direction, extending in the third direction to accommodate the third protrusion; and a fourth portion facing the second inner portion in the first direction, extending in the third direction to accommodate the fourth protrusion; the protrusion may include the third and fourth protrusions, and the portion may include the third and fourth protrusions.

[0015] For example, the first upper core may include a first outer portion disposed on one side of the second direction and extending in a third direction intersecting each of the first and second directions and including a first protrusion protruding in the first direction; and a first inner portion disposed on the other side of the second direction and extending in the third direction, and the first lower core may include a first recessed portion facing the first outer portion in the first direction and extending in the third direction to accommodate the first recessed portion; and a second recessed portion facing the first inner portion in the first direction and extending in the third direction, wherein the recessed portion includes the first protrusion, the recessed portion includes the first and second recessed portions, and a bottom surface of the first inner portion may be disposed to be in contact with an edge surface defining the second recessed portion.

[0016] For example, the second upper core may include a second outer portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and including a third protrusion protruding in the first direction; and a second inner portion disposed on the other side of the second direction and extending in the third direction, and the second lower core may include a third recessed portion facing the second outer portion in the first direction, extending in the third direction to accommodate the third recessed portion; and a fourth recessed portion facing the second inner portion in the first direction and extending in the third direction, wherein the recessed portion includes the third protrusion, the recessed portion includes the third and fourth recessed portions, and a bottom surface of the second inner portion may be disposed to be in contact with an edge surface defining the fourth recessed portion.

[0017] For example, the first inductance of the first transformer formed by the first upper core and the first lower core may be different from the second inductance of the second transformer formed by the second upper core and the second lower core.

[0018] For example, the first transformer may correspond to a forward transformer, and the second transformer may correspond to a flyback transformer.

[0019] For example, the coil section may include at least one primary coil disposed between the upper core and the lower core; and a secondary coil disposed between each of the upper core and the lower core and the primary coil.

[0020] The transformer according to the embodiment has excellent heat dissipation performance and excellent efficiency, and the manufacturing cost can be reduced and the assembly process can be simplified and reduced.

[0021] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0022] Figure 1 shows an exploded perspective view of a transformer according to one embodiment.

[0023] Figure 2 shows a partially exploded front view of the transformer illustrated in Figure 1.

[0024] Figure 3 shows a perspective view of the combination of the first or second transformer according to an embodiment.

[0025] FIG. 4a shows an exploded perspective view of an embodiment of the first or second transformer illustrated in FIG. 3.

[0026] FIG. 4b shows a perspective view of an embodiment of the upper core in the first or second transformer illustrated in FIG. 3.

[0027] Figure 4c shows a perspective view of the lower core in the first or second transformer illustrated in Figure 4a.

[0028] Fig. 5 shows a cross-sectional view according to one embodiment taken along the line I-I' shown in Fig. 3.

[0029] Fig. 6 shows a cross-sectional view according to another embodiment cut along the line I-I' shown in Fig. 3.

[0030] Figure 7a shows an exploded perspective view of a first or second transformer according to another embodiment.

[0031] Figure 7b shows a perspective view of the upper core in the first or second transformer illustrated in Figure 7a.

[0032] Figure 7c shows a perspective view of the lower core in the first or second transformer illustrated in Figure 7a.

[0033] Figure 8 shows a perspective view of a lower core according to another embodiment.

[0034] Fig. 9 is a graph showing the change in inductance according to the size of the side groove in the first transformer according to the embodiment.

[0035] Fig. 10 is a graph showing the change in inductance according to the size of the side groove in the second transformer according to the embodiment.

[0036] Fig. 11 is a graph showing the change in inductance according to the size of the side groove formed in the lower core in a transformer according to an embodiment.

[0037] Fig. 12a shows an exploded perspective view of a transformer according to another embodiment, and Fig. 12b shows a combined cross-sectional view taken along line Ⅱ-Ⅱ' of the transformer illustrated in Fig. 12a.

[0038] Figure 13 shows a perspective view of a transformer according to a comparative example.

[0039] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0040] Terms including ordinal numbers, such as "second," "first," etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a second component may be referred to as a "first component," and similarly, a first component may also be referred to as a "second component." The term "and / or" includes a combination of multiple related items described herein or any of multiple related items described herein.

[0041] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0042] In the description of the embodiments, the description that each layer (film), region, pattern or structure is formed "on" or "under" the substrate, each layer (film), region, pad or pattern includes both being formed directly or through the interposition of another layer. The reference to "on" or "under" each layer is explained based on the drawings. In addition, the thickness or size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and therefore does not entirely reflect the actual size.

[0043] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0044] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0045] Hereinafter, a transformer according to an embodiment will be described in detail with reference to the attached drawings. Regardless of the drawing reference numerals, identical or corresponding components will be given the same reference numerals, and redundant descriptions thereof will be omitted. In addition, although the transformer according to the embodiment will be described using the Cartesian coordinate system, it will be understood that the transformer may be described using another coordinate system. In the Cartesian coordinate system, the x-axis, the y-axis, and the z-axis illustrated in each drawing are orthogonal to each other, but the embodiment is not limited thereto. The x-axis, the y-axis, and the z-axis may also intersect each other. Hereinafter, for convenience of description, the z-axis direction will be referred to as the 'first direction', the y-axis direction will be referred to as the 'second direction', and the x-axis direction will be referred to as the 'third direction'.

[0046] Fig. 1 shows an exploded perspective view of a transformer (100) according to one embodiment, and Fig. 2 shows a partially exploded front view of the transformer illustrated in Fig. 1. To aid understanding, the coil portions (130, 140) illustrated in Fig. 1 are omitted in Fig. 2.

[0047] The core portion may include an upper core (110) and a lower core (120) positioned opposite to the upper core (110) in a first direction. In an embodiment, the upper core (110) may include a protruding portion protruding in the first direction, and the lower core (120) may include a concave portion coupled to the protruding portion. In this way, the upper core (110) and the lower core (120) may be coupled to each other in a protruding manner.

[0048] According to an embodiment, the upper core (110) may include first and second upper cores (112, 114) adjacent to each other in a second direction intersecting the first direction, and the lower core (120) may include first and second lower cores (122, 124) adjacent to each other in the second direction and facing the first and second upper cores (112, 114) in the first direction, respectively.

[0049] The first upper core (112) may include a first outer portion (OL1) and a first inner portion (IL1). The first outer portion (OL1) may be disposed on one side of the second direction, extend in a third direction intersecting each of the first and second directions, and include a first iron portion (PT1) protruding in the first direction.

[0050] The first inner leg (IL1) is disposed on the other side in the second direction and includes a second iron part (PT2) extending in the third direction and protruding in the first direction.

[0051] The first lower core (122) may include first and second sections (RE1, RE2).

[0052] The first yoke (RE1) faces the first outer leg (OL1) in the first direction and extends in the third direction to accommodate the first iron part (PT1).

[0053] The second yoke (RE2) faces the first inner leg (IL1) in the first direction and extends in the third direction to accommodate the second iron part (PT2).

[0054] In this way, the iron part may include first and second iron parts (PT1, PT2), and the main part may include first and second main parts (RE1, RE2).

[0055] The second upper core (114) may include a second outer portion (OL2) and a second inner portion (IL2). The second outer portion (OL2) may be disposed on one side in the second direction and may include a third protrusion (PT3) extending in a third direction intersecting each of the first and second directions and protruding in the first direction.

[0056] The second inner leg (IL2) may include a fourth iron part (PT4) disposed on the other side in the second direction, extending in the third direction, and protruding in the first direction.

[0057] The second lower core (124) may include third and fourth sections (RE3, RE4).

[0058] The third yoke (RE3) faces the second outer leg (OL2) in the first direction and extends in the third direction to accommodate the third iron part (PT3).

[0059] The fourth yoke (RE4) faces the second inner leg (IL2) in the first direction and extends in the third direction to accommodate the fourth iron part (PT4).

[0060] The iron part may further include third and fourth iron parts (PT3, PT), and the main part may further include third and fourth main parts (RE3, RE4).

[0061] According to an embodiment, a transformer formed by a first upper core (112) and a first lower core (122) is called a 'first transformer', and a transformer formed by a second upper core (114) and a second lower core (124) is called a 'second transformer'.

[0062] At this time, when the first transformer has a first inductance and the second transformer has a second inductance, the first and second inductances may be different from each other.

[0063] Meanwhile, referring again to FIG. 1, the coil portion may be at least partially positioned between the upper core (110) and the lower core (120).

[0064] The coil section may include a primary coil (130) and a secondary coil (140).

[0065] The primary coil includes at least one primary coil (130) disposed between an upper core (110) and a lower core (120). Additionally, a secondary coil (140) may be disposed between at least one of the upper core (110) or the lower core (120) and the primary coil (130).

[0066] In one embodiment, as illustrated, the primary coil (130) may include two primary coils (132, 134), and the secondary coil (140) may include two secondary coils (142, 144). One of the primary coils (132) may be disposed between the upper core (110) and the lower core (120), and the other of the primary coils (134) may be disposed between the primary coil (132) and the lower core (120).

[0067] One of the secondary coils (142) may be placed between the primary coil (132) and the upper core (110), and the other of the secondary coils (144) may be placed between the primary coil (134) and the lower core (120).

[0068] In another embodiment, unlike that shown in FIG. 1, it may include only one primary coil (132 or 134) and one secondary coil (142 or 144).

[0069] If the primary side is a Litz wire and the secondary side is a busbar structure, the structure of the transformer can be further simplified by adopting a printed circuit board (PCB) form as the driving frequency increases.

[0070] The transformer according to the embodiment can be applied to a printed circuit board (PCB) type transformer. Here, a PCB type transformer may refer to a transformer including a coil section (130, 140) in the form of a PCB.

[0071] Hereinafter, the combined appearance of the upper core (110) and the lower core (120) in the transformer (100) according to the above-described embodiment will be described with reference to the attached drawing.

[0072] FIG. 3 shows a perspective view of a combined first or second transformer according to an embodiment, FIG. 4a shows an exploded perspective view of an embodiment of the first or second transformer shown in FIG. 3, FIG. 4b shows a perspective view of an embodiment of an upper core in the first or second transformer shown in FIG. 3, and FIG. 4c shows a perspective view of a lower core in the first or second transformer shown in FIG. 4a.

[0073] The transformers illustrated in FIGS. 3 to 4c may be either the first or second transformers. Accordingly, the upper core (302) may correspond to the first or second upper core (112, 114), and the lower core (304) may correspond to the first or second lower core (122, 124).

[0074] In addition, the Y-th protrusion (PTY) illustrated in FIGS. 4a and 4b may correspond to the second or third protrusion (PT2, PT3) illustrated in FIG. 2, and the X-th protrusion (PTX) may correspond to the first or fourth protrusion (PT1, PT4). In addition, the Y-th recess (REY) may correspond to the second or third recess (RE2, RE3) illustrated in FIG. 2, and the X-th recess (REX) may correspond to the first or fourth recess (RE1, RE4), so that redundant descriptions of overlapping parts are omitted.

[0075] FIG. 5 shows a cross-sectional view according to one embodiment cut along the line I-I' shown in FIG. 3, and FIG. 6 shows a cross-sectional view according to another embodiment cut along the line I-I' shown in FIG. 3.

[0076] In one embodiment, the bottom surfaces of the yoke (REX, REY) may face a surface of the ferrule (PTX, PTY) that faces the bottom surface in the first direction with a gap therebetween. For example, referring to FIGS. 5 and 6, the bottom surfaces (B1, B2) of the yoke (REX) may face a surface (T1, T2) of the ferrule (PT1) that faces the bottom surface (B1, B2) in the first direction with a gap (G1, G2) therebetween.

[0077] Additionally, a step portion may be arranged on the inner side of the edge (ED1, ED2) of the yoke (REX, REY). For example, referring to Fig. 6, a step portion (ST) may be arranged on the inner side of the edge (ED1) of the yoke (REX).

[0078] The steel member (PTX, PTY) may include a catch supported by a step. For example, the steel member (PTX) may include a catch (DT) supported by a step (ST).

[0079] At this time, the step portion (e.g., ST) and the catch portion (e.g., DT) can be arranged in direct contact. That is, the step portion and the catch portion can be arranged in direct contact without the interposition of adhesives, etc., and the ridge portion (REX, REY) and the steel portion (PTX, PTY) can be combined in a fitting manner.

[0080] In addition, according to an embodiment, when the step portion and the catch are arranged in direct contact, heat can be easily transferred from the lower core (304) to the upper core (302), and heat can be easily transferred from the upper core (302) to the lower core (304).

[0081] FIG. 7a shows an exploded perspective view of a first or second transformer according to another embodiment, FIG. 7b shows a perspective view of an upper core (302) in the first or second transformer illustrated in FIG. 7a, and FIG. 7c shows a perspective view of a lower core (304) in the first or second transformer illustrated in FIG. 7a.

[0082] Unlike the first or second transformer illustrated in FIGS. 4A to 4C, the first or second transformer illustrated in FIGS. 7A to 7C further includes side grooves (HS1, HS2). Except for this, the descriptions of FIGS. 4A to 4C, 5, and 6 can also be applied to FIGS. 7A to 7C, and therefore, redundant descriptions thereof are omitted herein.

[0083] The lower core (304) may further include side grooves (HS1, HS2). The side grooves (HS1, HS2) communicate the internal space of the yoke with the external space, and may be formed on the outer edge side among the edges defining the yoke. Referring to FIGS. 7A to 7C, the first side groove (HS1) communicates the internal space of the yoke (REX) with the external space, and may be formed on the outer edge (EGO) side among the edges (ED1) defining the yoke (REX), and the second side groove (HS2) communicates the internal space of the yoke (REY) with the external space, and may be formed on the outer edge (EG1) side among the edges (ED2) defining the yoke (REY).

[0084] Figure 8 shows a perspective view of a lower core according to another embodiment.

[0085] The lower core (304) illustrated in FIG. 8 may include a combination of a step portion (ST) and side grooves (HS1, HS2).

[0086] The step portion (ST) illustrated in Fig. 8 corresponds to the step portion (ST) illustrated in Fig. 6, and the side grooves (HS1, HS2) correspond to the side grooves (HS1, HS2) illustrated in Fig. 7c, respectively. Except for this, Fig. 8 is identical to the lower core (304) illustrated in Figs. 4c and 6, and therefore, redundant descriptions are omitted.

[0087] Meanwhile, phase-shifted full-bridge (PSFB) converters have been widely applied in low-voltage DC-DC converters (LDCs) due to their zero-voltage switching (ZVS) characteristics and small output filter size. However, due to their wide input and output voltage specifications, the low nominal operating duty ratio of PSFB converters leads to an extended freewheeling period and large circulating current. Consequently, PSFB converters must address high conduction losses.

[0088] To solve this problem, a forward converter (forward-flyback) transformer with an insulated structure and high-efficiency power conversion characteristics is being proposed, which reduces the size of the transformer by increasing the utilization rate of the transformer.

[0089] For example, the transformer according to the embodiment may be applied to a forward flyback transformer. In this case, the first transformer described above may correspond to a forward transformer, and the second transformer may correspond to a flyback transformer.

[0090] Fig. 9 is a graph showing the change in inductance according to the size of the side grooves (HS1, HS2) in the first transformer according to the embodiment, where the horizontal axis represents the length of the side grooves (HS1, HS2) and the vertical axis represents the inductance.

[0091] When the first transformer according to the embodiment is applied to a forward transformer, the required inductance is 90 μH to 110 μH, and when the size of the side grooves (HS1, HS2) is increased to increase the heat dissipation effect, the minimum required inductance value can be maintained when the size (e.g., length) of the side grooves (HS1, HS2) is 17 mm. At this time, the inductance can be expressed as in the following mathematical expression 1.

[0092]

[0093] Here, L represents inductance, μo represents the permeability in a vacuum, Ae represents the effective cross-sectional area through which the magnetic flux passes, N represents the number of turns, lg represents the sum of all gaps in the first direction between the upper core (110) and the lower core (120), le represents the length of the magnetic path through which the magnetic flux passes, and μr represents the relative permeability.

[0094] When the size of the side grooves (HS1, HS2) increases, the effective cross-sectional area (Ae) of Equation 1 may decrease, resulting in a decrease in the inductance (L) value.

[0095] Fig. 10 is a graph showing the change in inductance according to the size of the side grooves (HS1, HS2) in the second transformer according to the embodiment, where the horizontal axis represents the length of the side grooves (HS1, HS2) and the vertical axis represents the inductance.

[0096] When the second transformer according to the embodiment is applied to a flyback transformer, the required inductance is 27 μH to 33 μH, and when the size of the side grooves (HS1, HS2) is increased to increase the heat dissipation effect, the minimum required inductance value, such as the above-described mathematical expression 1, can be maintained when the size (e.g., length) of the side grooves (HS1, HS2) is 17 mm. It can be seen that this exhibits the same effect as a forward transformer.

[0097] Fig. 11 is a graph showing the change in inductance according to the size of the side grooves (HS1, HS2) formed in the lower core (120) in the transformer (100) according to the embodiment, where the horizontal axis represents the rate of decrease in the size of the side grooves (HS1, HS2), and the vertical axis represents the percentage of inductance, respectively.

[0098] In the transformer, the size of the side grooves (HS1, HS2) is set to be approximately 41% or less of the total length of the outer edge (EG1) (X1 in Fig. 8). The reason for setting this is that, as shown in Fig. 11, if the size of the side grooves (HS1, HS2) is greater than 41% of the total length of the outer edge (EG1) (X1 in Fig. 8), the inductance may decrease more than the inductance that must be maintained at a minimum.

[0099] Fig. 12a shows an exploded perspective view of a transformer (200) according to another embodiment, and Fig. 12b shows a combined cross-sectional view taken along line Ⅱ-Ⅱ' of the transformer (200) shown in Fig. 12a.

[0100] Hereinafter, only the parts that are different from the transformer (100) according to the above-described embodiment in the transformer (200) according to another embodiment illustrated in FIGS. 12a and 12b will be described, and overlapping descriptions for the same parts will be omitted. That is, the parts whose descriptions are omitted in FIGS. 12a and 12b can be applied to the description of the transformer (100) according to the embodiment.

[0101] A transformer (200) according to another embodiment includes an upper core (312) and a lower core (314). The upper core (312) and the lower core (314) correspond to the upper core (302) and the lower core (304) according to one embodiment, respectively, and perform the same function. However, unlike the upper core (302), the upper core (312) does not include a second ferrous portion (PT2) but only includes a first ferrous portion (PT1).

[0102] In addition, unlike as shown in FIG. 5, as shown in FIG. 12b, the bottom surface (T3) of the first iron part (PT1) is placed in contact with the bottom surface (B1) of the first main part (RE1) without being spaced apart from it.

[0103] Additionally, the bottom surface (T4) of the first inner leg portion (IL1) is arranged in contact with the edge surface (ES) defining the second yoke portion (RE2). Although not shown, the second inner leg portion (IL2) and the second outer leg portion (OL2) may have shapes symmetrical in the second direction with respect to the first inner leg portion (IL1) and the first outer leg portion (OL1), respectively.

[0104] That is, the first upper core (312) includes a first outer portion (OL1) disposed on one side in the second direction and extending in a third direction intersecting each of the first and second directions and including a first protruding portion (PT1) protruding in the first direction, and a first inner portion (IL1) disposed on the other side in the second direction and extending in the third direction, and the first lower core (314) includes a first recess (RE1) facing the first outer portion (OL1) in the first direction and extending in the third direction to accommodate the first protruding portion (PT1), and a second recess (RE2) facing the first inner portion (IL1) in the first direction and extending in the third direction. At this time, the bottom surface (T4) of the first inner portion (IL1) may be disposed in contact with an edge surface (ES) defining the second recess (RE2).

[0105] Although not shown, the second upper core may include a second outer portion disposed on one side in the second direction and including a third ferrule extending in a third direction intersecting each of the first and second directions and protruding in the first direction, and a second inner portion disposed on the other side in the second direction and extending in the third direction, and the second lower core may include a third portion facing the second outer portion in the first direction and extending in the third direction to accommodate the third ferrule, and a fourth portion facing the second inner portion in the first direction and extending in the third direction.

[0106] The bottom surface of the second inner portion can be arranged in contact with the edge surface defining the fourth inner portion.

[0107] Hereinafter, transformers of comparative examples and embodiments are described with reference to the attached drawings.

[0108] Figure 13 shows a perspective view of a transformer according to a comparative example.

[0109] The transformer according to the comparative example illustrated in Fig. 13 may include an upper core (10), a lower core (20), and gap paper (GP1, GP2). The upper core (10) has an outer leg (OL) and an inner leg (IL). The outer leg (OL) may protrude from one side in the second direction toward the lower core (20) in the first direction and extend in the third direction, and the inner leg (IL) may protrude from the other side in the second direction toward the lower core (20) in the first direction and extend in the third direction.

[0110] At this time, the first gap paper (GP1) is placed between the outer leg (OL) and the lower core (20), and the second gap paper (GP2) is placed between the inner leg (IL) and the lower core (20). Here, 'gap paper' means paper placed in the gap.

[0111] The inductance of the transformer by a comparative example that does not consider the gap is expressed as in the following mathematical expression 2.

[0112]

[0113] If the transformer according to the comparative example is applied to a forward flyback transformer, gap paper (GP1, GP2) of appropriate thickness must be placed between the upper core (10) and the lower core (20) to control the inductance of the forward transformer and the inductance of the flyback transformer, respectively.

[0114] In order to assemble the upper core (10), lower core (20), and gap paper (GP1, GP2) in the transformer by comparative example, adhesive layers are required on the upper and lower parts of the gap paper (GP1, GP2), and the adhesive is deformed at high temperatures, has deviations in characteristics, and has a high frequency of defects occurring during assembly.

[0115] On the other hand, according to the embodiment, since the gap paper is not used to control the inductance, the upper cores (110, 302, 312) and the lower cores (120, 304, 314) can be assembled without requiring a separate adhesive, and the inductance can be controlled relatively easily by cutting the protrusions (PTY, PTX) in the upper core (110) or forming the recesses (REY, REX) deeper. That is, according to the embodiment, when the height of the gaps (G1, G2) within the recesses (RE1, RE2, RE3, RE4), i.e., the gaps (G1, G2), are to be increased, the inductance value can be easily controlled by adjusting the protruding height of the protrusions (PTX, PTY) of the upper core (302). At this time, when using equipment capable of processing the upper core (110, 302) with a precision of several micrometers, the size of the gap (G1, G2) can be precisely processed to precisely and easily control the inductance. As a result, the manufacturing cost of the transformer of the embodiment can be reduced, and the assembly process can be simplified and shortened.

[0116] Also, referring to Fig. 2, let us assume that the lower core (120) is cooled using coolant (300). At this time, in the case of the transformer according to the comparative example, heat transfer from the lower core (20) to the upper core (110) is blocked by the gaps (GP1, GP2), so the coolant (300) can cool only the lower core (20).

[0117] On the other hand, in the case of the embodiment, since the upper core (110, 312) and the lower core (120, 314) are in direct contact without a gap, the heat of the upper core (110, 312) is transferred to the cooling water (300) via the lower core (120, 314), so that the overall temperature of the core portion (110, 120) can be reduced, and the efficiency of the transformer can be increased more than in the comparative example.

[0118] In particular, in the case of another embodiment (200), the bottom surface (T3) of the first protrusion (PT1) in the upper core (312) is arranged in direct contact with the bottom surface (B1) of the first ridge (RE1), and the bottom surface (T4) of the first inner leg (IL1) is arranged in direct contact with the edge surface (ES) defining the second ridge (RE2), so that the heat of the upper core (312) can be better transferred to the lower core (314). As a result, the heat generation temperature is reduced, which reduces the loss of the core, and thus the efficiency can be further improved.

[0119] In addition, in the comparative example, the coolant (300) is placed only below the lower core (120), whereas in the embodiment, since heat transfer is smoothly achieved between the upper core (110) and the lower core (120), the location of the coolant (300) is not limited. That is, according to the embodiment, the coolant (300) may be placed in contact with the upper core (110).

[0120] In addition, according to an embodiment, by providing side grooves (HS1, HS2) in the lower core (120), the heat of the lower core (120) can be further reduced by allowing the heat of the lower core (120) to be discharged to the outside through the side grooves (HS1, HS2).

[0121] Table 1 below shows the heating temperature and efficiency of the comparative examples and the examples, respectively.

[0122] Comparison Example 1 Implementation Example 2 Implementation Example 3 Implementation Example Heating Temperature Upper Core 52.7℃ 46.5℃ 45.3℃ 44.8℃ Lower Core 36.0℃ 42.2℃ 41.0℃ 40.3℃ Efficiency 93.5% 94% 94.2% 94.3%

[0123] Here, the first embodiment corresponds to a transformer without side grooves (HS1, HS2), the second embodiment represents a transformer with side grooves (HS1, HS2), and the third embodiment represents the embodiment illustrated in FIGS. 12a and 12b.

[0124] Although the above has been described focusing on embodiments, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present embodiment. For example, each component specifically shown in the embodiments can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

[0125] The mode for carrying out the invention has been sufficiently described in the above-mentioned “Best mode for carrying out the invention.”

[0126] The transformer according to the embodiment can be used in a power supply device of an electronic device, etc.

Claims

1. A core section including an upper core and a lower core arranged in a first direction opposite to the upper core; A coil portion at least partially disposed between the upper core and the lower core; The upper core includes an iron portion protruding in the first direction, A transformer wherein the lower core includes a main body that is coupled to the iron body.

2. In paragraph 1, A transformer in which the bottom surface of the above-mentioned portion faces the surface of the above-mentioned iron portion facing the first direction with a gap therebetween.

3. In paragraph 1, A step is placed on the inner edge of the above-mentioned part, A transformer in which the above iron part includes a catch supported by the above step part.

4. In paragraph 3, A transformer in which the above-mentioned step portion and the above-mentioned catch are placed in direct contact.

5. In paragraph 1, The above lower core A transformer that communicates the inner space of the above-mentioned portion with the outer space and includes a side groove formed on the outer edge of the edge defining the above-mentioned portion.

6. In paragraph 5, A transformer in which the size of the above side groove is 41% or less of the total length of the above outer edge.

7. In paragraph 1, The upper core includes first and second upper cores adjacent to each other in a second direction intersecting the first direction, A transformer comprising first and second lower cores which are adjacent to each other in the second direction and which face the first and second upper cores, respectively.

8. In paragraph 7, The above first upper core A first outer portion including a first iron portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and protruding in the first direction; and A first inner portion is disposed on the other side of the second direction, and includes a second iron portion extending in the third direction and protruding in the first direction, The above first lower core A first portion facing the first outer portion and extending in the third direction to accommodate the first iron portion; and It includes a second portion facing the first inner portion and extending in the third direction to accommodate the second iron portion, The above iron part includes the first and second iron parts, The above-mentioned part is a transformer including the first and second parts.

9. In paragraph 7, The above second upper core A second outer portion including a third iron portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and protruding in the first direction; and A second inner portion is disposed on the other side of the second direction, and includes a fourth iron portion extending in the third direction and protruding in the first direction, The above second lower core A third portion facing the second outer portion and the first direction and extending in the third direction to accommodate the third iron portion; and A fourth portion is included, which faces the second inner portion and the first direction and extends in the third direction to accommodate the fourth iron portion, The above iron part includes the third and fourth iron parts, The above-mentioned part is a transformer including the third and fourth parts.

10. In paragraph 7, The above first upper core A first outer portion including a first iron portion disposed on one side of the second direction, extending in a third direction intersecting each of the first and second directions, and protruding in the first direction; and It includes a first inner portion disposed on the other side of the second direction and extending in the third direction, The above first lower core A first portion facing the first outer portion and extending in the third direction to accommodate the first iron portion; and Including the first inner portion and the second portion facing the first direction and extending in the third direction, The above iron part includes the first iron part, The above-mentioned portion includes the first and second portions, A transformer in which the bottom surface of the first inner portion is placed in contact with the edge surface defining the second portion.

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