Transformers

Abstract

The transformer according to this embodiment includes a core portion, and a first coil portion and a second coil portion at least a portion of which is housed within the core portion, the second coil portion having a plurality of conductive wires crossing each other in a specific region to reduce an inductance deviation between the conductive wires, and the first coil of the first coil portion can receive a terminal terminal via a terminal bobbin.

Description

【Technical Field】 【0001】 The present invention relates to a transformer. 【Background Art】 【0002】 A variety of coil components such as a transformer or a line filter are mounted in a power supply device of an electronic device. 【0003】 A transformer can be included in an electronic device for various purposes. For example, a transformer can be used to perform an energy transfer function of transferring energy from one circuit to another circuit. Also, a transformer can be used to perform a boosting or bucking function of changing the magnitude of a voltage. Further, since only an inductive coupling (coupling) is provided between the primary side and secondary side windings, a transformer having a feature that no DC path is directly formed can also be used for the purpose of DC blocking and AC passing, or for insulation separation between both circuits. 【0004】 FIG. 1 is an exploded perspective view showing an example of the configuration of a general transformer. 【0005】 Referring to FIG. 1, a general slim-type transformer 10 includes a core part including an upper core 11 and a lower core 12, and a secondary side coil 13 and a primary side coil 14 provided between the upper and lower cores 11 and 12. The secondary side coil 13 is composed of a plurality of conductive metal plates, and the primary side coil 14 usually has a form in which a conductive wire is wound. Depending on the configuration, a bobbin (not shown) may be arranged between the upper core 11 and the lower core 12. 【0006】 In the transformer shown in FIG. 1, the primary side coil and the secondary side coil overlap in the vertical direction. However, when a conductive wire is applied instead of the conductive metal plate to the secondary side coil, the primary side coil and the secondary side coil can be arranged to overlap each other in the horizontal direction. 【0007】 However, when conductive wires are used in the secondary coil, they must be arranged side by side on a plane for slimming purposes. As a result, when forming a turn around the center pin of the core, the inner conductive wire closest to the center pin becomes the shortest, and the outer conductive wire furthest from it becomes the longest, causing an inductance deviation. Such an inductance deviation causes a current imbalance, which in turn causes excessive heat generation. [Overview of the project] [Problems that the invention aims to solve] 【0008】 The technical problem that this invention aims to solve is to provide a transformer that is slim, yet can reduce heat generation, and can prevent heat generation caused by inductance deviations due to differences in the length of coils made of conductive wires. 【0009】 Another technical problem that the present invention aims to solve is to provide a slim transformer that can be further miniaturized and that can ensure leakage inductance. 【0010】 The technical problems that this invention aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understandable to a person with ordinary skill in the art to which this invention belongs from the following description. [Means for solving the problem] 【0011】 A transformer according to one embodiment includes a core portion including an upper core and a lower core, a coil portion partially disposed within the core portion, and a bobbin portion disposed between the core portion and the coil portion, wherein the coil portion includes a first coil and a second coil at least partially disposed on the side surface of the first coil, and the bobbin portion includes a first bobbin having a first housing portion for housing the first coil and a second bobbin having a second housing portion for housing the second coil, wherein the first bobbin includes a first extension portion extending from the first housing portion toward the second bobbin, and the second housing portion is disposed on the first extension portion. 【0012】 The first bobbin comprises a first top portion, a first bottom portion positioned below the first top portion, and the first top portion and the 1 The first extension includes a first intermediate portion positioned between the bottom portion and the first extension portion, the intermediate portion having an inner surface that defines a first through hole, and the first extension portion can be positioned on the first bottom portion. 【0013】 The second bobbin includes a second top portion having a second through-hole in its center, a second bottom portion located below the second top portion, and a second intermediate portion located between the second top portion and the second bottom portion, and at least a portion of the first bobbin can be accommodated in recesses defined on the lower surface of the second top portion and the inner surface of the second intermediate portion. 【0014】 The first extension can face the lower surface of the second bottom portion. 【0015】 The second top portion includes a first guide and a second guide that face each other in the longitudinal direction of the second bobbin with the second through hole in between, and each of the first guide and the second guide can project upward from the upper surface of the second top portion and extend in the longitudinal direction of the second bobbin. 【0016】 The upper core can be positioned between the first guide and the second guide. 【0017】 The second top portion may further include a third through hole that faces the second through hole in the longitudinal direction, with the second guide in between. 【0018】 The first top portion further includes a coil lead-out portion located on its upper surface, the coil lead-out portion being exposed by passing through the third through-hole. 【0019】 The second top portion further includes a blind hole formed on its bottom surface toward the interior of the second guide, and the first top portion may further include a protruding pin positioned between the coil lead portion and the first through hole, protruding upward from the top surface and inserted into the blind hole. 【0020】 The shortest distance from the lower surface of the lower core to the first coil and the shortest distance from the lower surface of the lower core to the second coil may be different. 【0021】 The shortest distance from the lower surface of the lower core to the first coil may be smaller than the shortest distance from the lower surface of the lower core to the second coil. 【0022】 The second bobbin includes a second extension extending from the second housing in the direction of the first bobbin, and the first housing can be positioned below the second extension. 【0023】 A portion of the second housing can be positioned between the first coil and the second coil. 【0024】 The core portion includes a first outer foot portion, a second outer foot portion, and a midfoot portion disposed between the first outer foot portion and the second outer foot portion, and the shortest distance between the first coil and the second coil may be 0.1 to 0.3 times the shortest distance between the outermost edge of the first coil and one adjacent outer foot portion of the first and second outer foot portions. 【0025】 The core part can further include a first space formed between the first outer foot part and the middle foot part to accommodate a part of the bobbin part, and a second space formed between the second outer foot part and the middle foot part to accommodate a tab of the bobbin part. 【0026】 The ratio of a second distance, which is the shortest distance between the first coil and the second coil in the first space or the second space, to a first distance, which is the shortest distance between the first coil and the second coil outside the first space and the second space, can be 1 to 1.3. 【0027】 The shortest distance from the lower surface of the lower core to the first coil can be 0.3 to 0.7 times the shortest distance from the lower surface of the lower core to the second coil. 【0028】 A flat panel display device according to another embodiment includes a power supply unit in which a transformer is disposed. The transformer includes a core part including an upper core and a lower core, a coil part partially disposed in the core part, and a bobbin part disposed between the core part and the coil part. The coil part includes a first coil and a second coil at least partially disposed on a side surface of the first coil. The bobbin part includes a first bobbin in which a first accommodating part for accommodating the first coil is formed, and a second bobbin in which a second accommodating part for accommodating the second coil is formed. The first bobbin includes a first extension part extending in a direction from the first accommodating part toward the second bobbin, and the second accommodating part is disposed on the first extension part. 【0029】 Further embodiments of the transformer include a core section including an upper core and a lower core, a first coil section and a second coil section, at least a portion of which are disposed between the upper core and the lower core, and a terminal bobbin coupled to one side of the second coil section in the first direction, wherein the first coil section includes a first coil and a first bobbin having a first through hole through which the middle leg of the core section passes and housing the first coil, and the second coil section includes a second coil and a second bobbin having a second through hole housing at least a portion of the first coil section and housing the second coil, wherein the terminal bobbin includes a plurality of first terminals spaced apart from each other in a second direction intersecting the first direction on one side in the first direction, and an opening formed on the other side facing the one side in the first direction into which the one side of the second coil section is inserted, and both ends of the first coil are pulled out from the first bobbin and connected to different first terminals among the plurality of first terminals of the terminal bobbin, respectively. 【0030】 The first bobbin comprises a first upper plate and a third bobbin separated from the upper plate in a direction intersecting the first and second directions. 1 The lower plate and the above 1 Upper plate and the above 1 The first upper plate includes a first side wall portion positioned between it and a lower plate, and the first upper plate may include pull-out grooves on the first upper plate that allow the ends to be pulled out. 【0031】 The terminal bobbin includes a recess on the other side in the first direction, and the recess can overlap the lead groove in the third direction. 【0032】 The terminal bobbin has the recess mosquito The device includes a plurality of first wire guides extending toward each of the plurality of first terminals, and both ends of the first coil drawn out through the lead groove can extend toward the corresponding first terminal along different first wire guides from the plurality of first wire guides. 【0033】 The second bobbin may include a second upper plate, a second lower plate spaced apart from the second upper plate in a third direction intersecting the first and second directions, and a second side wall portion positioned between the second upper plate and the second lower plate. 【0034】 The second coil includes a first portion located on one side of the second bobbin in a first direction from the second through-hole, and a second portion located on the other side of the second through-hole opposite to the first portion, wherein the second coil includes a plurality of conductive wires arranged around the second through-hole, one side of the plurality of conductive wires extending so as to be located on the second portion, and the other side of the plurality of conductive wires extending so as to be located at both ends on the first portion, and at least a portion of the first and second conductive wires of the plurality of conductive wires overlapping on the second portion, and the second bobbin may have a region in the second portion where the overlap occurs and a recess in which at least a portion overlaps in the third direction. 【0035】 The recess can be formed in the second lower plate. 【0036】 The second bobbin may further include a plurality of second terminals arranged on the second lower plate in the first part. 【0037】 The first conductive wire and the second conductive wire may have a symmetrical shape in the first direction with respect to the second through-hole. 【0038】 The plurality of conductive wires may further include a third conductive wire that forms a turn on the outside of the first conductive wire on a plane, and a fourth conductive wire that forms a turn on the outside of the second conductive wire on a plane. 【0039】 The third and first conductive wires can be arranged in parallel to form a turn, and the fourth and second conductive wires can be arranged in parallel to form a turn. 【0040】 The second upper plate may include a first partition wall portion that protrudes upward in the third direction from the edge on the first portion side in the first direction and extends in the second direction. 【0041】 The second bobbin comprises the second side wall portion and the plurality The A second wire guide extending in the first direction between the two terminals may be further included. 【0042】 The second bobbin may further include a second partition wall portion that protrudes downward from the second lower plate in the third direction and extends in the second direction between the second through hole and the recess. 【0043】 The second bobbin further includes a first support portion projecting in the first direction from the second partition wall toward the second through hole, and a second support portion facing the first support portion with the second through hole in between, wherein the first support portion and the second support portion can support the first coil portion. 【0044】 A circuit board according to yet another embodiment includes a substrate and a transformer disposed on the substrate, the transformer including a core portion including an upper core and a lower core, a first coil portion and a second coil portion which are at least partially disposed between the upper core and the lower core, and a terminal bobbin coupled to one side of the second coil portion in a first direction, the first coil portion including a first coil and a first bobbin which houses the first coil and which has a first through hole through which the middle leg of the core portion passes, the second coil portion including a second coil and the first coil The terminal bobbin includes a second bobbin for housing the second coil, having a second through-hole for housing at least a portion of the coil portion, the terminal bobbin includes a plurality of first terminals spaced apart from each other in a second direction intersecting the first direction on one side in the first direction, and an opening formed on the other side facing the one side in the first direction into which the one side of the second coil portion is inserted, the ends of the first coil can be pulled out from the first bobbin and connected to different first terminals among the plurality of first terminals of the terminal bobbin, respectively. [Effects of the Invention] 【0045】 The transformer according to the embodiment minimizes the difference in length between conductive wires by arranging the multiple conductive wires constituting the coil to intersect each other in one region. 【0046】 Furthermore, short-circuiting the terminal pins improves the inductance deviation between conductive wires that form the same turn in parallel, thereby reducing heat generation. 【0047】 Furthermore, the bobbin can be made slimmer by having an opening in the region where conductive wires cross. 【0048】 In other embodiments, the transformer ensures leakage inductance by controlling the separation distance between the first coil section and the second coil section. 【0049】 Furthermore, the coupling structure between the first bobbin and the second bobbin ensures an insulating distance between the primary coil and the core, thereby ensuring leakage inductance. 【0050】 The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understandable to a person with ordinary skill in the art to which the present invention belongs from the following description. [Brief explanation of the drawing] 【0051】 [Figure 1] This is an exploded perspective view showing an example of a typical slim-type transformer configuration. 【0052】 [Figure 2a] This is a plan view of a transformer according to one embodiment. 【0053】 [Figure 2b] This is a bottom view of a transformer according to one embodiment. 【0054】 [Figure 2c] This is a cross-sectional view showing a transformer according to one embodiment, cut along the line A-A' in Figure 2a. 【0055】 [Figure 3a] This is a perspective view of the first bobbin according to one embodiment. 【0056】 [Figure 3b] This is a plan view of the first bobbin according to one embodiment. 【0057】 [Figure 4a] This is a plan view of the second bobbin according to one embodiment. 【0058】 [Figure 4b] This is a perspective view of the second bobbin according to one embodiment. 【0059】 [Figure 4c] This is a rear perspective view of the second bobbin according to one embodiment. 【0060】 [Figure 5a] This is a plan view of a terminal bobbin according to one embodiment. 【0061】 [Figure 5b] This is a perspective view of a terminal bobbin according to one embodiment. 【0062】 [Figure 6] This figure shows an example of the arrangement of adhesive parts in a transformer according to one embodiment. 【0063】 [Figure 7a] This figure shows an example of the coil arrangement configuration of the second coil section according to one embodiment. 【0064】 [Figure 7b] This figure shows the pin map of the second coil section according to one embodiment. [Figure 7c]This is a circuit diagram of a transformer according to one embodiment. 【0065】 [Figure 7d] This figure illustrates a configuration in which superposition occurs between conductive wires in the second part of the second coil section according to one embodiment. 【0066】 [Figure 7e] This is a rear view of the second coil section according to one embodiment. [Figure 7f] This is a side view of the second coil section according to one embodiment. 【0067】 [Figure 7g] This is a plan view showing an example of a second bobbin configuration according to another embodiment. 【0068】 [Figure 8a] This is a perspective view of a transformer according to yet another embodiment. 【0069】 [Figure 8b] Here is a plan view of a transformer according to another embodiment. 【0070】 [Figure 9] Furthermore, here is an exploded perspective view of a Transformer according to another embodiment. 【0071】 [Figure 10] This is a perspective view of the first bobbin according to another embodiment. 【0072】 [Figure 11] This is an exploded perspective view of the bobbin section in yet another embodiment. 【0073】 [Figure 12] Furthermore, Figure 8b shows a cross-sectional view of a transformer according to another embodiment, obtained by cutting along the line B-B'. 【0074】 [Figure 13a]Furthermore, Figure 8b shows a cross-sectional view of a transformer according to another embodiment, obtained by cutting along the line A-A'. 【0075】 [Figure 13b] This is an enlarged view of the "C" portion of Figure 13a. 【0076】 [Figure 14] This figure shows an example of a power supply circuit configuration for an electronic product. [Modes for carrying out the invention] 【0077】 The present invention can be modified in various ways and may have many different embodiments, but we will attempt to describe specific embodiments with illustrations in the drawings. However, this should not be understood as limiting the present invention to specific embodiments, but rather as including all modifications, equivalents, or substitutes that fall within the spirit and technical scope of the present invention. 【0078】 Terms including ordinal numbers, such as "second" and "first," can be used to describe a variety of components, but the components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from another. For example, within the scope of the present invention, the second component may be named the first component, and similarly, the first component may be named the second component. The terms "and / or" include combinations of multiple related description items or any one of multiple related description items. 【0079】 When it is mentioned that one component is “linked” or “connected” to another component, it should be understood that it may be directly linked or connected to the other component, but there may also be other components in between. On the other hand, when it is mentioned that one component is “directly linked” or “directly connected” to another component, it should be understood that there are no other components in between. 【0080】 In the description of the embodiments, the statement that each layer (film), region, pattern, or structure is formed "on" or "under" the substrate, each layer (film), region, pad, or pattern includes all those formed directly or interposed by other layers. The criteria for on or under each layer are explained based on the drawings. Furthermore, the thickness and size of each layer (film), region, pattern, or structure in the drawings are modifiable for clarity and convenience of explanation and do not directly reflect the actual size. 【0081】 The terms used in this application are used solely to describe specific embodiments and are not intended to limit the invention. A singular expression includes plural expressions unless the context explicitly indicates otherwise. In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, stages, operations, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof. 【0082】 Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideally or excessively formal unless expressly defined herein. 【0083】 The transformer according to this embodiment will be described in detail below with reference to the attached drawings. 【0084】 Figure 2a is a plan view of a transformer according to one embodiment, Figure 2b is a rear view of a transformer according to one embodiment, and Figure 2c is a cross-sectional view showing a section of a transformer according to one embodiment cut along the line A-A' in Figure 2a. 【0085】 Referring together to Figures 2a and 2c, the transformer 100 according to one embodiment can include core sections 111 and 112, a first coil section 120, a second coil section 130, a terminal bobbin 140, and a core fixing section 150. Each component will be described in detail below. 【0086】 The core portions 111 and 112 have the characteristics of a magnetic circuit and can act as a path for magnetic flux. The core portions 111 and 112 may include an upper core 111 that is coupled on the upper side and a lower core 112 that is coupled on the lower side. The two cores 111 and 112 may have a vertically symmetrical shape or an asymmetrical shape. However, for the sake of explanation, the following description will assume that they have a vertically symmetrical shape. 【0087】 Each of the upper core 111 and the lower core 112 may include a flat body portion and a plurality of leg portions projecting from the body portion in the thickness direction (i.e., in the three axis directions) and extending in a predetermined direction. The plurality of leg portions may include two outer feet extending in a uniaxial direction (here, 1 axis) on a plane and spaced apart from each other in the other axis direction (here, 2 axes), and a single metafoot CL positioned between the two outer feet. 【0088】 When the upper core 111 and the lower core 112 are joined vertically, the outer and midfoot portions of the upper core 111 face the corresponding outer and midfoot portions of the lower core 112. Here, a gap of a predetermined distance (e.g., 10-200 μm, but not necessarily limited to this) can be formed between at least some of the opposing pairs of outer and midfoot portions. teeth This is the space formed by the separation between the upper core 111 and the lower core 112, and the gap can be filled with air (i.e., an air gap) or with adhesive components. 【0089】 Furthermore, the core portions 111 and 112 may, but are not necessarily limited to, magnetic materials such as iron or ferrite. 【0090】 The first coil section 120 may include a first bobbin B1 having a first through-hole (or first hollow) CH1 in the center, and a first coil C1 wound within the housing space of the first bobbin so as to form multiple turns around the first through-hole CH1. 【0091】 The second coil section 130 may include a second bobbin B2 having a second through-hole (or second hollow, see Figure 4a) CH2 in the center, and a second coil C2 arranged within the housing space of the second bobbin B2 so as to form a turn around the second through-hole CH2. Here, at least a portion of the first coil section 120 can be placed in the second through-hole CH2. Thus, at least a portion of the first coil section 120 and the second coil section 130 can overlap in the first axial direction and the second axial direction. The first coil C1 and the second coil C2 may, but are not limited to, a multi-winding of a rigid metal, such as copper conductive wire, wound several times in a helical or planar helical shape. For example, the first coil C1 may be an enameled wire (USTC wire) wrapped in fiber filament, a Litz wire, or a triple-insulated wire (TIW). 【0092】 In this embodiment, the first coil section 120 can correspond to the primary coil of the transformer 100, and the second coil section 130 can correspond to the secondary coil of the transformer 100, but it is not necessarily limited to this. 【0093】 Furthermore, the diameter of the second coil C2 may be 0.7 to 0.9 times the height of the second bobbin B2 in the three axial directions, but is not necessarily limited to this. 【0094】 The first coil section 120 will be described in more detail later, based on Figures 3a and 3b, and the second coil section 130 will be described in more detail later, based on Figures 4a to 4c. 【0095】 The terminal bobbin 140 is coupled to one side in a single axial direction with the first coil section 120 and the second coil section 130 joined together, and provides a terminal for electrically connecting the first coil C1 to an external circuit (not shown). The specific form of the terminal bobbin 140 will be described in more detail later with reference to Figures 5a and 5b. 【0096】 The core fixing portion 150 is for a more stable bond between the upper core 111 and the lower core 112, and may, but is not limited to, a polymer resin tape wrapped around the outer surface of the core portion 110 once or more times in two-axis and three-axis directions. 【0097】 Figure 3a is a perspective view of the first bobbin according to one embodiment, and Figure 3b is a plan view of the first bobbin according to one embodiment. 【0098】 Referring to Figures 3a and 3b, a first bobbin B1 according to one embodiment may include a first upper plate TP1, a first lower plate BP1, and a first side wall SW1 positioned between the first upper plate TP1 and the first lower plate BP1. The first side wall SW1 defines a first hollow CH1 and, together with the bottom surface of the first upper plate TP1 and the top surface of the first lower plate BP1, can form a housing space in which a first coil C1 is housed. 【0099】 A first lead groove DH1 and a second lead groove DH2 can be arranged on one side edge of the first upper plate TP1 where the terminal bobbin 140 is connected in the uniaxial direction. One end of the conductive wire constituting the first coil C1 can be pulled upward through the first lead groove DH1, and the other end of the first coil C1 can be pulled upward through the second lead groove DH2. Both ends of the first coil C1 pulled out through the first lead groove DH1 and the second lead groove DH2 can extend onto the terminal bobbin 140. Furthermore, the first lead groove DH1 and the second lead groove DH2 can be superimposed in the triaxial direction with the second recess RC2 of the terminal bobbin 140, which will be described later. 【0100】 Figure 4a is a plan view of the second bobbin according to one embodiment, Figure 4b is a perspective view of the second bobbin according to one embodiment, and Figure 4c is a rear perspective view of the second bobbin according to one embodiment. 【0101】 Referring to Figures 4a to 4c, the second bobbin B2 according to one embodiment may include a second upper plate TP2, a second lower plate BP2, and a second side wall SW2 positioned between the second upper plate TP2 and the second lower plate BP2. The second side wall SW2 defines a second hollow CH2 and, together with the bottom surface of the second upper plate TP2 and the top surface of the second lower plate BP2, can form a housing space in which the second coil C2 is housed. 【0102】 On the second upper plate TP2, a first projection PT1 and a second projection PT2 are arranged on one side to which the terminal bobbin 140 is connected in the uniaxial direction, projecting upward in the 3axial direction, and a first partition wall PA1 can be arranged on the other end facing the one side in the uniaxial direction, which is bent upward and extends in the 3axial direction. 【0103】 Second lower plate BP 2 In this configuration, a third projection PT3, a fourth projection PT4, a second partition wall PA2, a first support SP1, and a first recess RC1 can be arranged on one side in the 1-axis direction, projecting downward in the 3-axis direction. 2 In this configuration, multiple second terminals TM2 and second support parts SP2 can be arranged on the other side facing one side in the axial direction. Multiple second terminals TM2 can be arranged side by side, spaced apart from each other in the axial direction. 【0104】 The first recess RC1 is the second lower plate BP 2It can have a planar shape that is recessed from one end toward the other. The width of the first recess RC1 in the two axes can gradually decrease from one end toward the other. For example, the first recess RC1 can have a semicircular or semi-elliptical planar shape, but is not necessarily limited to these. A part of the second coil C2 can be exposed through the first recess RC1. This will be described in more detail later with reference to Figures 7d to 7f. 【0105】 The second partition wall PA2 can extend in two axial directions, and the first support part SP1 can project from the second partition wall PA2 in one axial direction to the other side, that is, towards the center of the second hollow CH2. The second support part SP2 can project to one side in one axial direction, and together with the first support part SP1, it can support the first coil part 120 when the first coil part 120 is inserted into the second hollow CH2 from top to bottom in three axial directions. 【0106】 On the other hand, a second wire guide WG2 can be positioned between the first bulkhead PA1 and the multiple terminal terminals TM2 on a plane. The second wire guide WG2 may include a central part WG2_C and side parts WG2_S1 and WG2_S2. The central part WG2_C may project from the second side wall SW2 toward the second terminal terminal TM2, and its width in the two axes may decrease toward the second terminal terminal TM2. The side parts WG2_S1 and WG2_S2 have a plate-like shape and can be positioned to connect the lower end of the first bulkhead PA1 and the central part WG2_C. For example, each of the side parts WG2_S1 and WG2_S2 may have an arc-shaped planar shape that connects the lower end of the first bulkhead PA1 and the central part WG2_C, and the second wire guide WG2 may have a "T"-shaped planar shape. 【0107】 The second wire guide WG2 can act as a guide for the innermost conductive wire among the multiple conductive wires constituting the second coil C2. Furthermore, the multiple conductive wires (not shown) constituting the second coil C2 are exposed upward in the portion where the second upper plate TP2 and the second lower plate BP2 do not overlap each other in the three axial directions, that is, between the first partition PA1 and the second terminal TM2 on a plane. Thus, the side portions WG2_S1 and WG2_S2 of the second wire guide WG2, together with the first partition PA1, support the second coil C2 and the first coil C2. 1 This can contribute to ensuring sufficient insulation distance between the two components and between the second coil and the core portion 110. 【0108】 The protruding parts PT1, PT2, PT3, and PT4 are inserted into the grooves H1, H2, H3, and H4 of the terminal bobbin 140, which will be described later, thereby connecting and fixing the second bobbin B2 and the terminal bobbin 140 to each other. 【0109】 Figure 5a is a plan view of a terminal bobbin according to one embodiment, and Figure 5b is a perspective view of a terminal bobbin according to one embodiment. 【0110】 Referring together to Figures 5a and 5b, the terminal bobbin 140 may include a third upper plate TP3, a third lower plate BP3, and a third side wall SW3 positioned between the third upper plate TP3 and the third lower plate BP3. 【0111】 The third upper plate TP3 is equipped with the first hole H1, the second hole H2, and the first wire guide WG1, while the third lower plate BP3 can be equipped with the third hole H3 and the fourth hole H4. 【0112】 On the terminal bobbin 140, an opening OP is formed on one side where the third side wall SW3 is not located in one axial direction, so that the second coil portion 130 can be inserted, and a plurality of first terminal terminals TM1 are arranged on the other side facing the one side in one axial direction. Second recesses RC2 can be formed above and below the opening OP in the three axial directions in the third upper plate TP3 and the third lower plate BP3, respectively, so as to be recessed to the other side in one axial direction. Here, the second recess formed in the third upper plate TP3 and the second recess formed in the third lower plate BP3 may have different planar shapes, but are not necessarily limited to this. The planar shape of the second recess RC2 is preferably such that it does not obstruct the first coil portion 120 (i.e., does not overlap it in the three axial directions) or obstructs it to the minimum extent when the terminal bobbin 140 is connected with the first coil portion 120 and the second coil portion 130 connected. This is to prevent the heat generated in the first coil C1 located in the first coil section 120 from being trapped by the terminal bobbin 140. 【0113】 Multiple first wire guide WGs 1 Each of these can extend from the second recess RC2 toward a different first terminal terminal TM1. The number of first terminal terminals TM1 and the number of first wire guides WG1 can, but are not necessarily limited to, correspond to each other. One end of the first coil C1, drawn out through one of the lead grooves DH1, DH2 of the first bobbin B1, can be exposed upward through the second recess RC2 formed in the third upper plate TP3. The exposed end of the first coil C1 extends toward the first terminal terminal TM1 along the first wire guide WG1 and can then be electrically connected to the first terminal terminal TM1. 【0114】 Each of the multiple first terminal terminals TM1 can be composed of a terminal pin TP that extends in one axis direction and is then bent in three axes. The portion of the terminal pin TP that extends in one axis direction can be electrically connected and fixed to one end of the first coil C1 by soldering or the like, and the portion that extends in three axes can penetrate the terminal bobbin 140 downwards in three axes and be exposed below the terminal bobbin 140. The portion exposed below the terminal bobbin 140 can be electrically connected and fixed to the circuit board. This configuration using terminal pin TP can also be applied to the second terminal terminal TM2, similar to the first terminal terminal TM1. 【0115】 The transformer 100 according to this embodiment may include multiple adhesive parts in addition to the core fixing part 150 described above in order to maintain higher reliability. This will be explained with reference to Figure 6. 【0116】 Figure 6 shows an example of the arrangement of the adhesive parts of a transformer according to one embodiment. 【0117】 Referring to Figure 6, the first to third adhesive portions AD1, AD2, and AD3 are positioned between the first upper plate TP1 of the first bobbin B1 of the first coil portion 120 and the surface having an opening in the core portion 110, thereby enabling a stronger bond between the core portion 110 and the first coil portion 120. 【0118】 Furthermore, a fourth adhesive portion AD4 can be positioned between the second recess RC2 of the terminal bobbin 140 and the first upper plate TP1. 【0119】 Furthermore, the fifth adhesive portion AD5 and the sixth adhesive portion AD6 can be positioned along the line in which the first coil portion 120 and the second coil portion 130 are in contact in one axial direction. It goes without saying that the fifth adhesive portion AD5 and the sixth adhesive portion AD6 can also be in contact with the bottom surface of the body portion of the upper core 111 or the top surface of the body portion of the lower core 112, along with the line in which the first coil portion 120 and the second coil portion 130 are in contact. 【0120】 Each adhesive portion may be made with a resin-based adhesive, but is not necessarily limited to this. Furthermore, although not shown in the figures, adhesive portions can also be formed at the points where the first to fourth protrusions PT1, PT2, PT3, and PT4 are joined to the first to fourth grooves H1, H2, H3, and H4. 【0121】 The arrangement of the second coil C2 according to the embodiment will be described in more detail below with reference to Figures 7a to 7g. 【0122】 Figure 7a shows an example of the coil arrangement configuration of the second coil section according to one embodiment. 【0123】 In Figure 7a, for the sake of explanation, the second coil C2 is shown as being placed on the second bobbin B2, but it should be noted that in reality, the second coil C2 is placed between the second upper plate TP2 and the second lower plate BP2 of the second bobbin B2. 【0124】 Referring to Figure 7a, the second bobbin B2 may include a central portion CP, a first portion 1P located on one side in the axial direction from the central portion CP or the second through-hole CH2, and a second portion 2P located on the other side opposite the first portion 1P in the axial direction from the central portion CP or the second through-hole CH2. 【0125】 A second through-hole CH2 can be placed in the central part CP, and multiple terminal pins T1, T2, T3, T4, T5, T6, T7, and T8 that constitute the second terminal TM2 can be arranged in the first part 1P in a biaxial direction. 【0126】 The second coil C2 may contain multiple conductive wires L1, L2, L3, and L4. 【0127】 The ends of multiple conductive wires L1, L2, L3, and L4 are electrically connected to different terminal pins T1, T2, T3, T4, T5, T6, T7, and T8, respectively, and each can form a turn around the second through-hole CH2. 【0128】 For example, both ends of the first conductive wire L1 are connected to the second terminal pin T2 and the fifth terminal pin T5, and both ends of the third conductive wire L3 are connected to the first terminal pin T1 and the sixth terminal pin T6, respectively. Also, both ends of the second conductive wire L2 are connected to the fourth terminal pin T4 and the seventh terminal pin T7, respectively, and both ends of the fourth conductive wire L4 are connected to the third terminal pin T3 and the eighth terminal pin T8, respectively. 【0129】 On the other hand, the first conductive wire L1 and the third conductive wire L3 can intersect in the second section 2P such that at least a portion of them overlap with the second conductive wire L2 and the fourth conductive wire L4 in three axes. Also, multiple conductive wires L1, L2, L3, and L4 can be arranged side by side in two axes in the central section CP and extend in one axis. In Figure 7a, multiple conductive wires L1, L2, L3, and L4 are shown not overlapping each other in three axes in the central section CP, but in the region adjacent to the second section 2P, some overlap in three axes may occur. That is, one side of each of the multiple conductive wires L1, L2, L3, and L4 can extend so that it is positioned on the second section 2P, and the other side can extend so that both ends are positioned on the first section 1P. 【0130】 As a result of the configuration of the second coil section 130 described above, there are parts in the second section 2P and other areas where superposition occurs between the conductive wires constituting the second coil C2. However, from the perspective of individual conductive wires, this constitutes only one turn, so the second coil C2 can be considered as being wound in a single layer. 【0131】 This terminal pin connection configuration and the intersection at part 2P are for inductance matching between sections that form the same turn from a circuit perspective. 【0132】 This will be explained with reference to Figures 7b and 7c. 【0133】 Figure 7b shows the pin map of the second coil section according to one embodiment, and Figure 7c is the circuit diagram of the transformer according to one embodiment. 【0134】 Referring to Figures 7b and 7c, the first conductive wire L1 and the third conductive wire L3 are connected in parallel to form the first turn NS2 for the first signal of the second coil section of the transformer, and the second conductive wire L2 and the fourth conductive wire L4 form the second turn NS3 for the second signal of the second coil section. In this case, the first terminal pin T1 and the second terminal pin T2 correspond to the input terminals for the first signal, and the fifth terminal pin T5 and the sixth terminal pin T6 correspond to the ground for the first signal. Also, the seventh terminal pin T7 and the eighth terminal pin T8 correspond to the input terminals for the second signal, and the fourth terminal pin T4 and 3 Terminal pin T 3 This corresponds to the ground for the second signal. Here, the grounds of each signal can be electrically connected to each other to form a so-called Center Tap CT structure. 【0135】 Returning to Figure 7a, the connection between the conductive wires and terminal pins described above causes the first conductive wires L1 and L3, which constitute the first turn section NS2 in parallel, to mirror (symmetrical) the second conductive wires L2 and L4, which constitute the second turn section NS3 in parallel, in one axial direction with respect to the second through-hole CH2. Therefore, since the first turn section NS2 and the second turn section NS3 have substantially the same conductive wire configuration, the inductance deviation due to the difference in conductive wire length is minimized, thereby reducing heat generation due to current unevenness. 【0136】 On the other hand, because the crossing of conductive wires occurs in the second part 2P of the second bobbin B2, superposition of conductive wires occurs in the three axial directions. Therefore, deformation of the second bobbin B2 can be prevented in the second part 2P only when the height of the second side wall SW2 of the second bobbin B2 is more than twice the thickness of the conductive wires. However, securing the height of the second side wall SW2 in this way makes the second bobbin B2 thicker overall, which can increase the total thickness of the transformer. This will be explained with reference to Figure 7d. 【0137】 Figure 7d is a diagram illustrating the form in which superposition occurs between conductive wires in the second part of the second coil section according to one embodiment. In Figure 7d, conductive wires L1, L2, L3, and L4 are shown as solid lines regardless of superposition to aid understanding. 【0138】 Referring to Figure 7d, the second part 2P of the second coil section has multiple superposition regions due to superposition combination pairs between multiple conductive wires. For example, in the second part 2P, a first region A1 is generated where the third conductive wire L3 and the fourth conductive wire superimpose on a plane, a second region A2 is generated where the first conductive wire L1 and the fourth conductive wire L4 superimpose on a plane, a third region A3 is generated where the second conductive wire L2 and the third conductive wire L3 superimpose on a plane, and a fourth region A4 is generated where the first conductive wire and the second conductive wire superimpose on a plane. 【0139】 In these regions A1, A2, A3, and A4, a larger accommodation space is required in the three axial directions than in the remaining regions. 【0140】 Therefore, by forming the first recess RC1 in the second bobbin B2, it is possible to prevent an increase in the thickness of the second bobbin B2. 【0141】 Figure 7e shows a rear view of the second coil section according to one embodiment, and Figure 7f shows a side view of the second coil section shown in Figure 7e, viewed in the direction of the arrow at the top of Figure 7e. 【0142】 Referring together to Figures 7e and 7f, a first recess RC1 having a semicircular planar shape is formed in each of the second lower plates BP2 of the second coil section 130. By having the first recess RC1, as shown in Figure 7f, even if the height h2 of the housing space (i.e., the height of the second side wall SW2) is less than twice the diameter D of the conductive wire, the crossing space for the conductive wires can be secured without deformation of the bobbin. Therefore, an increase in the thickness of the second bobbin B2 can be prevented. 【0143】 On the other hand, the maximum length h1 of the first recess RC1 in the axial direction is preferably greater than twice the diameter of each conductive wire (2*D), as shown in Figure 7d. Furthermore, the position of the first recess RC1 is preferably located within at least a portion of each of the four regions A1, A2, A3, and A4 where superposition between conductive wires occurs, as shown in Figure 7d. In addition, the planar area of ​​the first recess RC1 is preferably 50% to 90% of the sum of the areas of the four regions A1, A2, A3, and A4 where superposition between conductive wires occurs, but is not necessarily limited to this. 【0144】 Furthermore, the planar shape of the first recess RC1 is shown in Figure 7e Although it is shown as a semicircle, this is merely an example, and the shape is not limited to circles, track shapes, polygons, etc., as long as it includes at least a portion of each of the four regions A1, A2, A3, and A4 where superposition between conductive wires occurs. 【0145】 Figure 7g is a plan view showing an example of the configuration of the second bobbin according to another embodiment. 【0146】 The configuration of the second bobbin B2 in the other embodiment shown in Figure 7g is the same as the configuration of the second bobbin B2 described above with reference to Figure 4a, except for the short-circuit sections SP1, SPC, and SP2, so a redundant explanation will be omitted. 【0147】 Referring to Figure 7g, the first terminal pin T1 and the second terminal pin T2, which correspond to the input terminals of the first signal, can be short-circuited via the first short-circuit section SP1. Also, the seventh terminal pin T7 and the eighth terminal pin T8, which correspond to the input terminals of the second signal, can be short-circuited via the second short-circuit section SP2. Furthermore, the third to sixth terminal pins T3, T4, T5, and T6, which correspond to the ground in the center-tapped configuration, can be short-circuited via the center short-circuit section SPC. 【0148】 Here, each of the short-circuit sections SP1, SP2, and SPC can be implemented by soldering, but this is illustrative and not necessarily limited to this method; any method that enables a short circuit between terminal pins is acceptable. For example, each of the short-circuit sections SP1, SP2, and SPC can also be implemented by a conductor clip, a conductor pin, or a combination of these with soldering. 【0149】 In Figure 7g, the center short-circuit section SPC is shown as an integrated unit that short-circuits all of the third to sixth terminal pins T3, T4, T5, and T6. However, in other embodiments, the center short-circuit section SPC can also consist of a first center short-circuit section (not shown) that short-circuits the third terminal pin T3 and the fourth terminal pin T4, and a second center short-circuit section (not shown) that short-circuits the fifth terminal pin T5 and the sixth terminal pin T6. In such cases, the first center short-circuit section (not shown) and the second center short-circuit section (not shown) do not need to be electrically connected within the transformer. 【0150】 On the other hand, as mentioned above, the transformer 100 according to the embodiment can be used to form a circuit board (not shown) that constitutes a power supply unit (PSU) or the like, together with other magnetic elements (for example, an inductor). 【0151】 Figure 8a shows a perspective view of a transformer according to yet another embodiment, and Figure 8b shows a plan view of a transformer according to yet another embodiment. Furthermore, Figure 9 is an exploded perspective view of a transformer according to yet another embodiment, and Figure 10 is a perspective view of the first bobbin according to yet another embodiment. Furthermore, Figure 11 is an exploded perspective view of the bobbin section according to yet another embodiment. 【0152】 Referring together to Figures 8a to 11, the transformer 101 according to further embodiments may include a core section 110, bobbin sections B1 and B2, and terminal terminals TM1 and TM2. Each of these components will be described in detail below. 【0153】 The core portions 111 and 112 have the characteristics of a magnetic circuit and can act as a magnetic flux path. The core portions 111 and 112 may include an upper core 111 coupled at the top and a lower core 112 coupled at the bottom. The two cores 111 and 112 may be vertically symmetrical or asymmetrical. However, for the sake of explanation, the following disclosure will assume that they are vertically symmetrical. 【0154】 Each of the upper core 111 and the lower core 112 may include a flat body portion and a plurality of leg portions OL1-1, OL1-2, OL2-1, OL2-2, CL1, CL2 projecting from the body portion in the thickness direction (i.e., the Z-axis direction) and extending in a predetermined direction. For example, the plurality of leg portions OL1-1, OL1-2, CL1 of the upper core 111 may include two outer feet OL1-1, OL1-2 extending in one axis direction (here, the Y-axis) on a plane and spaced apart from each other in the other axis direction (here, the X-axis), and a single midfoot CL1 positioned between the two outer feet OL1-1, OL1-2. 【0155】 When the upper core 111 and the lower core 112 are joined vertically, the outer foot OL1-1, OL1-2 and the midfoot CL1 of the upper core 111 face the corresponding outer foot OL2-1, OL2-2 and the midfoot CL2 of the lower core 112. The outer foot pairs OL1-1 and OL2-1 on one side that face each other can be called the first outer foot, the outer foot pairs OL1-2 and OL2-2 on the other side can be called the second outer foot, and the midfoot pairs CL1 and CL2 can be called the midfoot. 【0156】 A gap of a predetermined distance (for example, 10 to 200 μm, but not necessarily limited thereto) can be formed between at least some of the opposing pairs of outer and middle feet. The inductance of the core 110 can be controlled by adjusting the size of the gap between one pair of middle feet and two pairs of outer feet, and the heat generation can be controlled by the number of gaps. 【0157】 Furthermore, the core portion 110 may, but is not limited to, a magnetic material such as iron or ferrite. 【0158】 The core part 110 is the bobbin part B1, B2 Because it surrounds a part of the outside, the bobbin part B1, B2 It can be assumed that a portion of the first coil section (not shown) and the second coil section (not shown) housed within the core section 110 are arranged within the core section 110. 【0159】 Bobbin section B1, B2 This can include a first bobbin B1 and a second bobbin B2. 【0160】 The first bobbin B1 and the second bobbin B2 each have a first through hole TH1 and a second through hole TH2, and the midfoot portions CL1 and CL2 of the core portion 110 can be aligned so as to pass through the first through hole TH1 and the second through hole TH2. 【0161】 The first bobbin B1 can be accommodated in at least part within the second bobbin B2 and may include a first top portion 121, a first intermediate portion 123, and a first bottom portion 122. 【0162】 The first top portion 121 and the first bottom portion 122 may each have a square planar shape with rounded corners, but are not necessarily limited to this. Furthermore, the first bottom portion 122 may have a planar shape that extends outward from the first top portion 121 in the direction of separation from the leg portion (i.e., in the X-axis direction). 【0163】 The first intermediate section 123 is positioned vertically between the first top section 121 and the first bottom section 122, and can insulate the conductive wires (not shown) constituting the first coil section from the intermediate foot section. The inner surface of the first intermediate section 123 can define the first through-hole TH1. In addition, the space defined by the lower surface of the first top section 121, the outer surface of the first intermediate section 122, and a portion of the upper surface of the first bottom section can function as a housing space for accommodating the conductive wires constituting the first coil section. 【0164】 The second bobbin B2 may include a second top portion 131, a second intermediate portion 133, a second bottom portion 132, and substrate support portions CBS1 and CBS2. 【0165】 The second intermediate section 133 is positioned vertically between the second top section 131 and the second bottom section 132, and can insulate the conductive wires (not shown) that constitute the second coil section from the conductive wires (not shown) that constitute the first coil section. Also, a part of the lower surface of the second top section 131, the second intermediate section 13 3 The space defined by the outer surface and a portion of the upper surface of the second bottom portion can function as a housing space for accommodating the conductive wires that constitute the second coil portion. 【0166】 Furthermore, the substrate support portions CBS1 and CBS2, which are spaced apart from each other in the longitudinal direction of the second bottom portion 132, can function to support the transformer 101 when mounted on a circuit board (not shown) of a device such as a PSU. Among the substrate support portions, a plurality of protrusions 136 can be formed around the second substrate support portion CBS2 located on the second terminal TM2 side, protruding downward and arranged side by side spaced apart from each other in the y-axis direction. The protrusions 136 support the transformer 101 on the substrate together with the second substrate support portion CBS2, and can also be drawn out from between the second top portion 131 and the second bottom portion 132, and can act as wire guides so that the ends of the conductive wires constituting the second coil portion extend to the second terminal TM2. 【0167】 In the center of the second top section 131 is the second through hole TH 2 A transformer is positioned, and terminal terminals TM1 and TM2 can be positioned at both ends in the direction of the long axis. Terminal terminals TM1 and TM2 can serve the function of fixing the transformer 101 to the circuit board (not shown) of the power supply unit (PSU) and as an electrical connection path between the first coil section and the second coil section (not shown) of the transformer 101 and the circuit board (not shown) of the power supply unit (PSU). 【0168】 More specifically, the first terminal TM1 may include a plurality of pins spaced apart from each other, and at least some of these pins may be electrically connected to one of the ends of the conductive wires constituting the first coil. For example, some of the multiple pins constituting the first terminal TM1 may face each other in the x-axis direction, and each of the pins may be arranged side by side along the y-axis. 【0169】 The second terminal TM2 may include a plurality of pins arranged side by side along the x-axis and spaced apart from one another, and at least some of these pins can be electrically connected to one of the ends of the conductive wires that constitute the second coil. 【0170】 On the upper surface of the second top portion 131, a first guide 134 and a second guide 135 are arranged, facing each other in the long axis direction (i.e., Y axis direction) of the second bobbin B2, with the second through hole TH2 in between, and extending in the short axis direction (i.e., X axis direction). Here, the first guide 134 can be positioned on the second terminal TM2 side, and the second guide can be positioned on the first terminal TM1 side. The upper core 111 is positioned between the first guide 134 and the second guide 135, which fixes the position of the upper core 111 and also increases the insulation distance between the upper core 111 and the terminal terminals TM1 and TM2. 【0171】 Furthermore, a reinforcing pattern section 136 can be placed on the upper surface of the second top section 131 between the second terminal TM2 and the first guide 134. For example, the reinforcing pattern section 136 can be arranged in a shape where patterns having an "F"-shaped planar shape are arranged opposite each other in the X-axis direction, but is not necessarily limited to this. The reinforcing pattern section 136 can improve the rigidity of the second top section 131 and prevent deformation, and the difference in height between the reinforcing pattern section 136 and the second top section 131 can form multiple grooves H1 and H2 extending in the X-axis direction, and can also play a role in increasing the insulation distance between the upper core 111 and the second terminal TM2. 【0172】 When the transformer 101 is constructed, at least a portion of the first bobbin B1 can be housed in a recess RC defined by the lower surface of the second top portion 131 and the inner surface of the second intermediate portion 133 of the second bobbin B2. 【0173】 Furthermore, when the first bobbin B1 and the second bobbin B2 are joined together, the upper surface of the first top portion 121 faces the lower surface of the second top portion 131, and the portion of the upper surface of the first bottom portion 122 that does not overlap with the first top portion 121 in the vertical direction (i.e., the portion that extends outward) faces the lower surface of the second bottom portion 132. 【0174】 Furthermore, the coil lead-out portion 124 of the first top portion 121 can be exposed upwards by passing through the third through-hole TH3 of the second top portion 131 when connected. The coil lead-out portion 124 is designed so that both ends of the conductive wires constituting the first coil portion can be easily pulled out and fixed from the upper surface of the second top portion 131, and immediately connected to the first terminal TM1. 【0175】 Also, the first top part 1 of the first bobbin B1 2 On the upper surface of 1, a protruding pin 125 is positioned between the first through-hole TH1 and the coil lead-out portion 124, projecting upward and extending in the X-axis direction. When the first bobbin B1 and the second bobbin B2 are joined, the protruding pin 125 can be inserted into a blind hole BH formed inside the second guide 135 on the bottom surface of the second top portion 131. This allows the first bobbin B1 and the second bobbin B2 to maintain a stronger and more stable bond, and a cross-section of the joined state is shown in Figure 6a. 【0176】 On the other hand, adhesive bonding can also be considered between the bobbin sections B1 and B2 and the core section 110 for a more robust bond. For example, see Figure 8As shown in b, the first bonding groups AD1, AD2, AD3, and AD4 can be arranged in a side bonding configuration between the outer legs of the core portion 110 and the bobbin portions B1 and B2 that are exposed in the Y-axis direction from the internal housing holes of the core portion 110. For example, the first bonding groups AD1, AD2, AD3, and AD4 may or may not be in contact with the bobbin portions B1 and B2, but it is preferable that they are arranged so that they are in full contact with at least the upper core 111 and the lower core 112, respectively, in order to fix the space between the upper core 111 and the lower core 112. 【0177】 Furthermore, second bonding groups AD5 and AD6 can also be placed between the bottom surface of the upper core 111 between the midfoot and outer foot and the top surface of the second bobbin B2. The aforementioned bonding parts AD1, AD2, AD3, AD4, AD5, and AD6 can prevent vibration caused by the air gap between the bobbin parts B1 and B2 and the core part 110. Here, adhesives with the same components can be applied to the first bonding groups AD1, AD2, AD3, AD4 and the second bonding groups AD5 and AD6, or adhesives with different components can be applied. However, it is preferable to apply a resin-based adhesive (Adhesive Resin) to the second bonding groups AD5 and AD6, but it is not necessarily limited to this. 【0178】 The diagram shows the housing state of the first coil section and the second coil section by the coupling structure of the bobbin sections B1 and B2 described above. 12 See the explanation below. 【0179】 Figure 12 is a cross-sectional view of a transformer according to one embodiment, obtained by cutting along the line B-B' in Figure 8b. 【0180】 Referring to Figure 12, bobbin sections B1 and B2 are positioned between the core section 110 and the coil sections 120 and 130. More specifically, the coil sections 120 and 130 and bobbin sections B1 and B2 are partially positioned across the first space SB1 and the second space SB2 within the core section 110. The first space SB1 and the second space SB2 can each have a configuration in which the leg sections are separated from each other in a direction (i.e., in the X-axis direction) with the midfoot sections CL1 and CL2 in between, and the rectangular cross-section extends in the Y-axis direction. Furthermore, the first space SB1 can be located between the midfoot sections CL1 and CL2 of the core section 110 and the one-sided outer foot section OL1-1 and OL2-1, and the second space SB2 can be located between the midfoot sections CL1 and CL2 and the other-sided outer foot section OL1-2 and OL2-2. 【0181】 The first bobbin B1 has a first coil section 1 2 A first storage section RP1 that accommodates 0, and a second bobbin from the first storage section RP1. B2 It may have a first extension EP1 extending in that direction. That is, the first housing RP1 may correspond to the portion obtained by removing the first extension EP1 from the first top portion 121, the first intermediate portion 123, and the first bottom portion 122. 【0182】 Second bobbin B2 The coil may have a second housing portion RP2 that accommodates the second coil portion 130, and a second extension portion EP2 that extends from the second housing portion RP2 in the direction of the first bobbin B1. That is, the second housing portion RP2 may include the portion of the second top portion 131 excluding the second extension portion EP2, a second intermediate portion 133, and a second bottom portion 132. 【0183】 Furthermore, the second housing section RP2 is positioned on the first extension section EP1, and the first housing section RP1 is positioned below the second extension section EP2. As a result, the shortest distance h1 from the lower surface of the lower core 112 to the first coil section 120 is different from the shortest distance h2 from the lower surface of the lower core 112 to the second coil section 130. That is, the shortest distance h1 from the lower surface of the lower core 112 to the first coil section 120 is smaller than the shortest distance h2 from the lower surface of the lower core 112 to the second coil section 130. For example, the shortest distance h1 from the lower surface of the lower core 112 to the first coil section 120 may be 0.3 to 0.7 times the shortest distance h2 from the lower surface of the lower core 112 to the second coil section 130. 【0184】 Furthermore, due to the aforementioned coupling structure of bobbin sections B1 and B2, the first coil section 120 and the second coil section 130 partially overlap from one outer foot section to the other outer foot section, while the remaining portion does not overlap. In the vertical direction, the first coil section 120 and the second coil section 130 do not necessarily have to overlap each other. 【0185】 At least a portion of the second coil section 130 is positioned on the side of the first coil section 120, and a portion of the second housing section RP2, i.e., the second intermediate section 133, is positioned horizontally between the first coil section 120 and the second coil section 130. 【0186】 Each of the first coil section 120 and the second coil section 130 may be a multi-winding structure in which a rigid metal conductor, such as copper conductive wire, is wound several times, but is not necessarily limited to this. Also, the thickness of the conductive wire constituting the second coil section 130 may be 50% to 150% of the thickness of the conductive wire constituting the first coil section 120, but is not necessarily limited to this. 【0187】 On the other hand, insulating parts 161 and 162 can be positioned between the bobbin sections B1 and B2 and the outer legs on both sides. The insulating parts 161 and 162 can extend outward from the upper surface of the second housing section RP2, then bend, further extend to surround the outside of the second housing section RP2 and the first extension section EP1, and then bend and extend to the lower surface of the first extension section EP1. This allows both the second coil section 130 and the first coil section 120 to be insulated from the outer legs of the core section 110. The insulating parts 161 and 162 may contain, but are not necessarily limited to, components with excellent insulating properties such as ketones and polyimides. 【0188】 The above-described structure allows for a significant increase in the insulation distance between the first coil section 120 and the core section 110. For example, the first insulation distance PATH1 above the first coil section 120 would immediately reach the lower surface of the upper bobbin if the second extension EP2 were absent, but the presence of the second extension EP2 extends it by at least the length of the second extension in the x-axis direction. Furthermore, the second insulation distance PATH2 below the first coil section 120 is extended by the length of the first extension EP1 in the x-axis direction and the lengths of the insulation sections 161 and 162 in the same direction. 【0189】 Furthermore, in addition to the leakage inductance due to the shortest distance β between the first coil section 120 and the second coil section 130, an additional leakage inductance can be secured by the horizontal displacement of the first housing section RP1 and the second housing section RP2. 【0190】 In the following section, we will examine the cross-section of the portion not surrounded by the core portion 110, referring to Figures 13a and 13b. 【0191】 Figure 13a is a cross-sectional view of a transformer according to another embodiment, cut along the line A-A' in Figure 8b, and Figure 13b is an enlarged view of section "C" in Figure 13a. 【0192】 Referring together to Figures 13a and 13b, the first extension EP1 does not need to be placed on the first bobbin B1 in the portion where the bobbin portions B1 and B2 are not surrounded by the core portion 110. Also, the shortest distance α between the first coil portion 120 and the second coil portion 130 in the portion where the bobbin portions B1 and B2 are not surrounded by the core portion 110, i.e., outside the first space SB1 and the second space SB2, may be the same as or different from the shortest distance β between the first coil portion 120 and the second coil portion 130 in the portion where the bobbin portions B1 and B2 are surrounded by the core portion 110. 【0193】 Preferably, the ratio of the shortest distances (β / α) can be between 1 and 1.3. If the ratio of the shortest distances (β / α) is less than 1, it causes an overall increase in the size of the transformer 101, and the change in leakage inductance is not significant. Conversely, if the ratio of the shortest distances (β / α) exceeds 1.3, the energy conversion efficiency of the transformer 101 decreases. However, this range corresponds to when the A-A' cutting line and the B-B' cutting line in Figure 8b intersect in the center of the midfoot on a plane, and the ratio of the shortest distances (β / α) can vary depending on the radius of curvature in the winding direction of the first intermediate section 123 and the second intermediate section 133. 【0194】 In the following section, a transformer 101 according to an embodiment will be described along with the circuit configuration on which the transformer 101 can be implemented, with reference to Figure 14. 【0195】 Figure 14 shows an example of a power supply circuit configuration for an electronic product. 【0196】 Referring to Figure 14, the circuit configuration of an electronic product, such as the power supply unit (i.e., PSU) of a flat panel TV, is shown, which includes a square wave generator 210, a resonant section 220, and a rectifier section 230. Flat panel TVs generally support other operating modes, such as a low-power mode, in addition to the normal mode, and high efficiency is required for each operating mode, so the resonant section 220 is implemented in the form of an LLC resonant converter. The LLC resonant converter includes a first inductor Lr, 221, a second inductor Lm, 222, and a capacitor Cr, 223, and the inductance Lm of the second inductor 222 can be considered as the inductance that operates the circuit. The resonant frequency changes depending on the operating frequency of the PSU, and factors that determine the operating frequency include the inductance Lr of the first inductor 221 and the capacitance Cr of the capacitor 223. If the inductance Lr of the first inductor 221 and the capacitance Cr of the capacitor 223 are not matched to appropriate values, the efficiency of the overall circuit will decrease or a situation will occur where normal operation is not possible. 【0197】 In the embodiment, the inductance L of a leakage inductance-integrated transformer such as transformer 101 corresponds to Lm in the resonant section 220, and the leakage inductance Lk corresponds to Lr. 【0198】 The Lk / Lm ratio required for a typical flat-panel TV PSU is around 10% to 20%, but conventional transformers had such low Lk values ​​that it was difficult to meet this requirement. 【0199】 More specifically, the leakage inductance of the transformer can be calculated using Equation 1 below. 【0200】 【number】 【0201】 In Equation 1, Lk is the leakage inductance, k is the coupling coefficient, and Lm is the inductance of the transformer. Here, the coupling coefficient (k) can be determined experimentally. For example, it can be determined as shown in Equation 2 below. 【0202】 【number】 【0203】 In Equation 2, X is the winding separation ratio, which represents the separation distance between the first coil section and the second coil section with respect to the shortest distance between the outermost edge of the first coil section, which defines the space in which the second coil section can be wound (hereinafter referred to as the "winding space" for convenience), and the adjacent outer foot section. 【0204】 More specifically, when both the first bobbin B1 and the second bobbin B2 are present, the shortest distance between the first coil section 120 and the second coil section 130 (i.e., β in Figure 5) corresponds to the distance between the outermost edge of the first coil section 120 and the innermost edge of the second coil section 130. Also, assuming that only the first bobbin B1 is present, the maximum distance that the second coil section 130 can make relative to the first coil section 120 within the winding space is the shortest distance from the outermost edge of the first coil section 120 to the adjacent outer foot section (i.e., d1 in Figure 12). 【0205】 The leakage inductance of the transformer varies with the coupling coefficient, which is particularly affected by the shortest distance between the first coil section 120 and the second coil section 130 inside the core section 110. 【0206】 However, the shortest distance β between the first coil section 120 and the second coil section 130 is determined by where the innermost part of the second coil section 130 is located within the winding space. If we only consider increasing the shortest distance β, when the winding space is fixed, the number of turns in the second coil section 130 is limited, and in order for the winding space to become larger, the size of the core section 110 must also become larger. Therefore, it is difficult to approach this from the perspective of expanding the winding space. 【0207】 Therefore, in this embodiment, leakage inductance can be secured by controlling the ratio of the shortest distance β between the first coil section 120 and the second coil section 130 to the shortest distance d2 from the outermost edge of the first coil section 120 to the adjacent outer foot section, i.e., the winding gap ratio. 【0208】 For example, the shortest distance β between the first coil section 120 and the second coil section 130 is preferably 0.1 to 0.3 times d1. This is because if the ratio is less than 0.1 times, the LLC matching of the circuit (e.g., PSU) board on which the transformer is mounted will be misaligned, causing the operating frequency to rise and resulting in problems where the board cannot be controlled. If it exceeds 0.3 times, the efficiency of the transformer 101 will decrease, which may cause oscillation on the board. However, this is an illustrative example assuming a typical PSU, and is not necessarily limited to this depending on the implemented circuit. 【0209】 In conclusion, referring to Equations 1 and 2, the leakage inductance is affected by the coupling coefficient (k), which is affected by the distance and superimposed area between the first and second coil sections. The transformer 101 according to the embodiment secured additional leakage inductance by controlling the separation distance between the first and second coil sections to lower the coupling coefficient and by causing the housing spaces of the first and second coil sections to be horizontally offset in order to increase the leakage inductance. 【0210】 Therefore, the transformer according to the embodiment is suitable for configuring the power supply unit of a flat panel TV because it can secure a high Lk value while remaining slim due to the bobbin coupling structure described above. 【0211】 In the transformer 101 according to the embodiment described so far, the coupling structure of the bobbin sections B1 and B2 ensures that, at least in the portion surrounded by the core section 110, the second housing section RP2 is positioned on the first extension section EP1 and the first housing section RP1 is positioned below the second extension section EP2, so that the first housing section RP1 and the second housing section RP2 do not overlap horizontally in at least a portion of the area. However, according to other embodiments, the space housing the first coil section 120 and the space housing the second coil section 130 can be parallel. 【0212】 Although the invention has been described above based on examples, these are merely illustrative and do not limit the invention. Those with ordinary skill in the art to which the invention pertains will understand that various modifications and applications not exemplified above are possible, as long as they do not deviate from the essential characteristics of these examples. For example, each component specifically shown in the examples can be modified and implemented. Any differences related to such modifications and applications should be interpreted as being within the scope of the invention as defined in the appended claims. [Industrial applicability] 【0213】 The modes for carrying out the invention have been sufficiently explained in the aforementioned "Modes for Carrying Out the Invention".

Claims

[Claim 1] A core section including an upper core and a lower core, A first coil section and a second coil section, at least a portion of which are disposed between the upper core and the lower core, Includes a terminal bobbin coupled to one side of the second coil portion in the first direction, The first coil portion includes a first coil and a first bobbin that houses the first coil, with the middle leg of the core portion passing through a first through hole. The second coil section includes a second coil, a second through-hole that accommodates at least a portion of the first coil section, and a second bobbin that accommodates the second coil. The terminal bobbin includes, on one side in the first direction, a plurality of first terminals spaced apart from each other in a second direction intersecting the first direction, and on the other side facing the one side in the first direction, an opening into which one side of the second coil portion is inserted. A transformer in which both ends of the first coil are drawn out from the first bobbin and connected to different first terminals among the plurality of first terminals of the terminal bobbin. [Claim 2] The first bobbin is It includes a first upper plate, a first lower plate spaced apart from the first upper plate in a third direction intersecting the first and second directions, and a first side wall portion disposed between the first upper plate and the first lower plate. The first upper plate is, The transformer according to claim 1, further comprising pull-out grooves on the first upper plate that allow the ends to be pulled out. [Claim 3] The aforementioned terminal bobbin is The first direction includes a recess on the other side, The recess is, The transformer according to claim 2, wherein the pull-out groove and the transformer overlap each other in the third direction. [Claim 4] The aforementioned terminal bobbin is It includes a plurality of first wire guides extending from the recess toward each of the plurality of first terminal terminals, The transformer according to claim 3, wherein both ends of the first coil drawn out through the lead groove extend to the first terminal along different first wire guides among the plurality of first wire guides. [Claim 5] The aforementioned second bobbin is The transformer according to claim 4, comprising: a second upper plate; a second lower plate spaced apart from the second upper plate in a third direction intersecting the first and second directions, respectively; and a second side wall portion disposed between the second upper plate and the second lower plate. [Claim 6] A first part positioned on one side of the second bobbin in the first direction from the second through hole, The second part includes the second through-hole and the second part located on the other side opposite to the first part, The second coil includes a plurality of conductive wires arranged around the second through-hole, One side of the plurality of conductive wires extends so as to be positioned on the second part, The other ends of the plurality of conductive wires extend so that both ends are positioned on the first portion. Of the plurality of conductive wires, at least a portion of the first conductive wire and the second conductive wire overlaps on the second portion. The aforementioned second bobbin is The transformer according to claim 5, wherein the second part has a recess in which at least a portion of the region where the superposition occurs is superimposed in the third direction. [Claim 7] The recess is, The transformer according to claim 6, formed on the second lower plate. [Claim 8] The aforementioned second bobbin is The transformer according to claim 6 or 7, further comprising a plurality of second terminals arranged on the second lower plate in the first part. [Claim 9] The transformer according to any one of claims 6 to 8, wherein the first conductive wire and the second conductive wire have a symmetrical shape in the first direction with respect to the second through-hole. [Claim 10] The aforementioned plurality of conductive wires are A third conductive wire that forms a turn on the outside of the first conductive wire on a plane, The transformer according to any one of claims 6 to 9, further comprising a fourth conductive wire that forms a turn on the outside of the second conductive wire in a plane. [Claim 11] The third conductive wire and the first conductive wire are arranged in parallel to form a turn. The transformer according to claim 10, wherein the fourth conductive wire and the second conductive wire are arranged in parallel to form a turn. [Claim 12] The second upper plate is, The transformer according to any one of claims 8 to 11, comprising a first partition wall portion that protrudes upward in the third direction from the edge of the first portion in the first direction and extends in the second direction. [Claim 13] The aforementioned second bobbin is The transformer according to claim 8, further comprising a second wire guide extending in the first direction between the second side wall and the plurality of second terminals. [Claim 14] The aforementioned second bobbin is The transformer according to any one of claims 6 to 13, further comprising a second partition wall portion projecting downward from the second lower plate in the third direction and extending in the second direction between the second through-hole and the recess. [Claim 15] The aforementioned second bobbin is A first support portion protruding in the first direction toward the second through-hole from the second partition wall portion, The present invention further includes a second support portion that faces the first support portion with the second through-hole in between, The transformer according to claim 14, wherein the first support portion and the second support portion support the first coil portion. [Claim 16] circuit board and The substrate includes a transformer, The aforementioned Transformer is A core section including an upper core and a lower core, A first coil section and a second coil section, at least a portion of which are disposed between the upper core and the lower core, Includes a terminal bobbin coupled to one side of the second coil portion in the first direction, The first coil portion includes a first coil and a first bobbin having a first through-hole through which the middle leg of the core portion passes, and which houses the first coil. The second coil section includes a second coil and a second bobbin having a second through-hole that accommodates at least a portion of the first coil section and that accommodates the second coil. The terminal bobbin includes, on one side in the first direction, a plurality of first terminals spaced apart from each other in a second direction intersecting the first direction, and on the other side facing the one side in the first direction, an opening into which the one side of the second coil portion is inserted. Both ends of the first coil are A circuit board drawn out from the first bobbin and connected to different first terminal terminals among the plurality of first terminal terminals of the terminal bobbin.

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