CIRCUIT BOARD HAVING COMPOSITE MAGNETIC COMPONENTS MOUNTED THEREON

The present invention relates to a main magnetic component applicable to a core module of an electric vehicle. A composite magnetic component according to one embodiment of the present invention comprises: a transformer that converts power on an input side to transmit same to an output side, and has a first core and a first coil disposed in the first core; a ZVS inductor that refluxes a residual current to the input side without FET operation loss, and has a second core and a second coil disposed within the second core; an output inductor that removes the ripple of a current on the output side, and has a third core and a third coil disposed in the third core; and an EMI inductor that reduces electric noise of the current on the output side, and has a fourth core and a fourth coil disposed in the fourth core. Here, the second core, the third core, and the fourth core are made of different materials, and the first core and the second core are made of the same material.

TECHNICAL FIELD

The present disclosure relates to a main magnetic component applicable to a core module of an electric vehicle.

BACKGROUND ART

An electric vehicle [xEV: a generic term for a hybrid electric vehicle (HEV),

a plug-in hybrid electric vehicle (PHEV), and an electric vehicle (EV)] includes a DC-DC converter, an on-board charger (OBC), and an inverter as core modules.

An electric vehicle is generally equipped with both a high-voltage battery for driving an electric motor and an auxiliary battery for supplying power to an electronic load, and the auxiliary battery may be charged by power of the high-voltage battery.

In this case, in order to charge the auxiliary battery, it is necessary to convert the DC power of the high-voltage battery into DC power corresponding to the voltage of the auxiliary battery through voltage drop. To this end, a DC-DC converter is used.

A high-voltage battery for an electric vehicle is designed to be slowly or quickly charged by external power. Here, an OBC is used as a charging device for converting AC electricity, which is external electricity, into DC power for the high-voltage battery.

These core modules may be configured such that two or more magnetic components are mounted on a circuit board in combination. In order to improve efficiency of use of electricity of an electric vehicle, research on technology related to combination and disposition of magnetic components for realizing system efficiency improvement, densification, and weight reduction has been increasingly conducted.

In particular, a compact structure and high efficiency are as important to large vehicle makers as price competitiveness. In order to realize a module having high performance characteristics in a confined space, high-density/high-performance design of a main magnetic component applied to the module needs to be performed.

DISCLOSURE

Technical Problem

It is an object of the present disclosure to provide a circuit board on which a high-density and high-efficiency magnetic component composite module applicable to a core module of an electric vehicle is mounted.

In particular, the present disclosure provides a circuit board having composite magnetic components mounted thereon as a high-density and high-efficiency circuit board applicable to a DC-DC converter module.

Technical Solution

A circuit board according to an embodiment of the present disclosure includes a board including a circuit unit formed thereon, a first module disposed on the board, and a second module disposed on the board so as to be adjacent to the first module and electrically connected to the first module.

Here, the first module includes a transformer including a first core and a first coil disposed in the first core and including primary and secondary coils in order to convert power on an input side and to transmit the converted power to an output side and a zero voltage switching (ZVS) inductor disposed adjacent to the transformer and including a second core and a second coil disposed in the second core in order to return a residual current to the input side.

In addition, the second module includes an output inductor including a third core and a third coil disposed in the third core in order to remove ripple components included in a current on the output side and an EMI inductor disposed adjacent to the output inductor and including a fourth core and a fourth coil disposed in the fourth core in order to reduce electric noise included in the current on the output side.

In one embodiment of the present disclosure, the first coil and the second coil are electrically connected to each other, and at least partially overlap each other in a first direction from the first core toward the second core. The third coil and the fourth coil are electrically connected to each other, and the third core and the fourth core at least partially overlap each other in a second direction perpendicular to the first direction. The first core includes a material identical to the material of the second core, and the second core includes a material different from the material of at least one of the third core and the fourth core.

Here, the first and second cores may include ferrite, and the third and fourth cores may include iron (Fe) and silicon (Si).

The circuit board according to at least one embodiment of the present disclosure further includes a first base at least partially disposed in the third core and configured to receive the third coil and a second base configured to receive the fourth core.

Here, in at least one embodiment of the present disclosure, the first base includes a third-coil-seating portion including a through-hole formed therein to allow a center leg of the third core to pass therethrough and configured to allow the third coil to be seated thereon, an inner side wall formed on the third-coil-seating portion so as to surround the through-hole, and an outer side wall formed on the outer circumference of the third-coil-seating portion and including a coil path slot formed therein to allow a flat wire coil escaping from the third core to pass therethrough.

In addition, in at least one embodiment of the present disclosure, the first base further includes a pair of third-core-outer-leg-slot portions formed in both sides of the third-coil-seating portion to allow a pair of outer legs of the third core to be inserted thereinto and located therein.

In addition, here, each of the third-core-outer-leg-slot portions may include a pair of first extension walls extending from the outer side wall in an outward direction, with the outer legs interposed therebetween.

In addition, in at least one embodiment of the present disclosure, the first base includes a first coil hole formed in one side of the third-coil-seating portion, and the third coil is disposed so as to be inserted into the first coil hole.

In addition, in at least one embodiment of the present disclosure, the first base further includes a fastening portion extending outside the third core from the third-coil-seating portion and including at least one fastening hole formed therein.

Meanwhile, in at least one embodiment of the present disclosure, the second base includes a fourth-core-seating portion configured to allow the fourth core to be seated and supported thereon and a fourth-coil-seating portion configured to allow the fourth coil to be seated thereon. The fourth-core-seating portion includes a pair of vertical walls disposed with the fourth core interposed therebetween and a seating protrusion protruding from the lower end of each of the vertical walls to support the fourth core seated thereon, and the fourth-coil-seating portion is formed so as to interconnect the pair of vertical walls in the fourth core.

Here, the second base may further include a pin portion extending from the fourth-coil-seating portion and including a pin hole formed therein.

Meanwhile, in at least one embodiment of the present disclosure, the first base and the second base are integrally formed with each other.

In at least one embodiment of the present disclosure, the first base, as another embodiment, may include a third-coil-seating portion including a through-hole formed therein to allow a center leg of the third core to pass therethrough and configured to allow the third coil to be seated thereon and a protruding portion protruding from one side of the third-coil-seating portion to a height lower than the thickness of a coil wire of the third coil and including a coil path slot formed therein to allow the third coil escaping from the third core to pass therethrough.

In addition, here, one end portion of the third coil may be disposed above the fourth core, and the circuit board may further include a bracket configured to surround an upper surface and both side surfaces of the fourth core in the state in which the third coil is disposed above the fourth core.

In at least one embodiment of the present disclosure, the third coil and the fourth coil are continuously formed using a single flat wire coil.

Here, the flat wire coil may be disposed so as to enter the third core, to be spirally wound around a center leg of the third core in a downward direction, to escape from the third core, and to be bent upward to penetrate the fourth core.

In addition, in at least one embodiment of the present disclosure, the third coil and the fourth coil are electrically connected to each other via the circuit unit.

In addition, the first module and the second module may be electrically connected to each other via the circuit unit.

In at least one embodiment of the present disclosure, the third core may further include nickel (Ni), and the fourth core may further include boron (B).

Advantageous Effects

According to the present disclosure, a circuit board on which high-density and high-efficiency composite magnetic components are mounted may be obtained, and efficiency of use of electricity of an electric vehicle may be improved by applying the circuit board to a core module of the electric vehicle.

BEST MODE

The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. The examples, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. It is to be understood that the present disclosure covers all modifications, equivalents, and alternatives falling within the scope and spirit of the present disclosure.

The suffixes “module” and “unit” used herein to describe configuration components are assigned or used in consideration only of convenience in creating this specification, and the two suffixes themselves do not have any distinguishable meanings or roles from a physicochemical point of view.

While ordinal numbers including “first”, “second”, etc. may be used to describe various components, they are not intended to limit the components. These expressions are used only to distinguish one component from another component.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, the phrase “A and/or B” means “(A), (B), or (A and B)”.

In the description of the embodiments, it will be understood that when an element, such as a layer (film), a region, a pattern or a structure, is referred to as being “on” or “under” another element, such as a substrate, a layer (film), a region, a pad or a pattern, the term “on” or “under” means that the element is directly on or under another element or is formed such that an intervening element may also be present. In addition, it will also be understood that criteria of “on” or “under” is on the basis of the drawing for convenience unless otherwise defined due to the characteristics of each of components or the relationship therebetween. The term “on” or “under” is used only to indicate the relative positional relationship between components and should not be construed as limiting the actual positions of the components.

For example, the phrase “B on A” merely indicates that B is illustrated in the drawing as being located on A, unless otherwise defined or unless A must be located on B due to the characteristics of A or B. In an actual product, B may be located under A, or B and A may be disposed in a leftward-rightward direction.

In addition, the thickness or size of a layer (film), a region, a pattern, or a structure shown in the drawings may be exaggerated, omitted or schematically drawn for the clarity and convenience of explanation, and may not accurately reflect the actual size.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments of the disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “include” or “have”, when used herein, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined, all terms used herein, which include technical or scientific terms, have the same meanings as those generally appreciated by those skilled in the art. The terms, such as ones defined in common dictionaries, should be interpreted as having the same meanings as terms in the context of pertinent technology, and should not be interpreted as having ideal or excessively formal meanings unless clearly defined in the specification.

A circuit board according to an embodiment of the present disclosure includes a board including a circuit unit formed thereon, a first module disposed on the board, and a second module disposed on the board so as to be adjacent to the first module and to be electrically connected to the first module.

Here, the board illustratively includes a PCB, and the circuit unit illustratively includes patterned plated wires formed to electrically connect various electronic elements on the PCB to each other.

The electrical connection between the first module and the second module is illustratively made through the circuit unit. That is, the first module and the second module may be electrically connected to each other via the plated wires on the board in a state of being mounted on the board.

In addition, the first module includes a transformer, which includes a first core and a first coil disposed in the first core and including primary and secondary coils in order to convert power on an input side and to transmit the converted power to an output side, and a ZVS inductor, which is disposed adjacent to the transformer and includes a second core and a second coil disposed in the second core in order to return a residual current to the input side.

In addition, the second module includes an output inductor, which includes a third core and a third coil disposed in the third core in order to remove ripple components included in a current on the output side, and an EMI inductor, which is disposed adjacent to the output inductor and includes a fourth core and a fourth coil disposed in the fourth core in order to reduce eletric noise included in the current on the output side.

Here, the first coil and the second coil may be electrically connected to each other, and may at least partially overlap each other in a first direction from the first core toward the second core. In addition, the third coil and the fourth coil may be electrically connected to each other, and the third core and the fourth core may at least partially overlap each other in a second direction perpendicular to the first direction. The electrical connection between the coils includes not only a case in which the corresponding coils are connected to each other in a manner of being formed so as to continuously extending using a single coil wire but also a case in which the corresponding coils are connected to each other via the circuit unit on the board.

Here, the material of the first core and the material of the second core may be identical to each other, and the material of the second core may be different from the material of at least one of the third core and the fourth core.

The third and fourth cores may include iron (Fe) and silicon (Si). In addition, the third core may further include nickel (Ni), and the fourth core may further include boron (B).

The third core is made of a material having relatively high saturated magnetic flux density (e.g. 1.6 T) and high DC-bias characteristics, and thus is suitable for high current (e.g. 100 A or more) and is capable of being miniaturized.

The fourth core is made of a material having high permeability (e.g. μi 30,000 at 100 kHz) and low loss characteristics, whereby inductance is improved by 50% compared to a core made of a crystalline metal and having the same size.

The first core and the second core are made of ferrite (e.g. Mn—Zn-based ferrite), whereby heat generation is reduced through low loss, and power density is increased.

Hereinafter, structures of the output inductor, the EMI inductor, the ZVS inductor, and the transformer according to embodiments will be described in detail with reference to the drawings.

First Embodiment of Output Inductor and EMI Inductor

A first embodiment of the output inductor and the EMI inductor according to the present disclosure will be described with reference toFIGS.1to4.

The output inductor includes a third core10and a third coil20disposed in the third core10.

In addition, the EMI inductor includes a fourth core40and a fourth coil50disposed in the fourth core40.

The third core10is formed in such a manner that an upper core portion11and a lower core portion12contact each other, and the upper core portion11and the lower core portion12are vertically symmetrical with each other with respect to the contact surface therebetween.

In detail, the upper core portion11of the third core10includes an upper plate11a, a pair of outer legs11bprotruding from both sides of the upper plate11aand extending vertically, and a center leg11cdisposed between the outer legs11b.

The fourth core40is disposed adjacent to one side of the third core10, and has a structure including a through-hole31aformed therein to allow the fourth coil50to pass therethrough.

If a first core and a second core are stacked to overlap each other in a vertical direction (the first direction) in an embodiment to be described later with reference toFIGS.20to22, the third core10and the fourth core40of this embodiment are disposed so as to overlap each other in a horizontal direction (the second direction). Such overlapping disposition is advantageous for increase in density and efficiency.

In this embodiment, the third coil20and the fourth coil50are continuously and integrally formed using a single flat wire coil.

That is, a single flat wire coil enters the third core10through one side of the third core10, is spirally wound around the center leg11cso as to extend downward, escapes from the third core10through the one side of the third core10, is bent upward, and then is bent horizontally to penetrate the fourth core40.

This embodiment includes an integrated base30and60in which a first base30and a second base60are integrally formed with each other, which will be described below.

First, the integrated base30and60includes a third-coil-seating portion31, in which a through-hole31ais formed to allow the center leg11cof the third core10to pass therethrough and a flat surface is formed around the through-hole31ato allow the third coil20to be seated thereon.

An inner side wall32is formed on the inner circumference of the third-coil-seating portion31so as to surround the through-hole31a, and outer side walls33aand33bare formed on the outer circumference of the third-coil-seating portion31.

A path slot33cis formed in one side of each of the outer side walls33aand33bso that the flat wire coil escaping from the third core10after being spirally wound in the downward direction in the third core10passes through the outer side wall33b.

Outer-leg-slot portions34_1and34_2in which the pair of outer legs11bof the third core10is located are formed in both sides of the third-coil-seating portion31.

In addition, the outer-leg-slot portions34_1and34_2include extension walls34a,34b,34c, and34dextending laterally from the outer side walls33aand33b.

That is, as shown inFIG.4, the first outer-leg-slot portion34_1includes a pair of extension walls34aand34bprotruding and extending laterally from the outer side walls33aand33bso as to be disposed with one outer leg11binterposed therebetween. In addition, the second outer-leg-slot portion34_2includes a pair of extension walls34cand34dprotruding and extending laterally from the outer side walls33aand33bso as to be disposed with the other outer leg11binterposed therebetween.

When the third core10and the integrated base30and60are assembled with each other, the center leg11cof the third core10is inserted into the through-hole31ain the third-coil-seating portion31, and the pair of outer legs11bof the third core10is located in the outer-leg-slot portions34_1and34_2, respectively, whereby the third-coil-seating portion31is disposed in the third core10.

Meanwhile, a fourth-core-seating portion61on which the fourth core40is seated is formed on one side of the integrated base30and60.

The fourth-core-seating portion61includes a bottom surface and a circumferential wall formed on an edge of the bottom surface.

The fourth core40is seated on the fourth-core-seating portion61such that an imaginary straight line passing through the through-hole is parallel to the bottom surface.

A first coil hole37into which the flat wire coil is inserted is formed between the fourth-core-seating portion61and the third-coil-seating portion31.

In addition, a pin portion36including a pin hole36ais formed on one side of the fourth-core-seating portion61, and a second coil hole62into which the flat wire coil is inserted is formed in the opposite side of the fourth-core-seating portion61.

The flat wire coil, which continuously forms the third coil20and the fourth coil50, passes through the first coil hole37from below to above, is bent horizontally to enter an upper portion in the third core10, is spirally wound around the center leg11cof the third core10in the downward direction, and then is seated on the bottom of the third-coil-seating portion31. Subsequently, the flat wire coil passes through the path slot33cin the outer side wall33b, is bent upward, is bent horizontally to be placed on the pin portion36, is bent horizontally via the pin portion36to pass through the through-hole in the fourth core40, and then is bent downward to be inserted into the second coil hole62. Here, a pin p may penetrate the flat wire coil placed on the pin portion36to be inserted into the pin hole36a.

Meanwhile, the integrated base30and60includes a fastening portion39extending horizontally from one side of the third-coil-seating portion31and including a fastening hole39afor fastening of a screw or the like.

Second Embodiment of Output Inductor and EMI Inductor

FIGS.5to7show a second embodiment of the output inductor and the EMI inductor, which will be described below.

In this embodiment, the structures of a third core110and a fourth core140are the same as those in the first embodiment, and therefore, detailed description thereof will be omitted.

Further, similar to the first embodiment, the third core110and the fourth core140are disposed so as to partially overlap each other in the horizontal direction (the second direction).

In this embodiment, a third coil120and a fourth coil150are not formed integrally or continuously, and a base is of a separation type, and includes a first base130and a second base160.

First, the first base130will be described in detail with reference toFIG.8.

The first base130includes a third-coil-seating portion131, in which a through-hole131ais formed to allow a center leg of the third core110to pass therethrough and a flat surface is formed around the through-hole131ato allow the third coil120to be seated thereon.

An inner side wall132is formed on the inner circumference of the third-coil-seating portion131so as to surround the through-hole131a, and outer side walls133aand133bare formed on the outer circumference of the third-coil-seating portion131.

A path slot133cis formed in one side of the outer side wall133bso that the flat wire coil escaping from the third core110after being spirally wound in the downward direction in the third core110passes through the outer side walls133aand133b.

Outer-leg-slot portions134_1and134_2in which a pair of outer legs of the third core110is located are formed in both sides of the third-coil-seating portion131.

In addition, the outer-leg-slot portions134_1and134_2include extension walls134a,134b,134c, and134dextending laterally from the outer side walls133aand133b.

That is, as shown inFIG.8, the first outer-leg-slot portion134_1includes a pair of extension walls134aand134bprotruding and extending laterally from the outer side walls133aand133bso as to be disposed with one outer leg interposed therebetween. In addition, the second outer-leg-slot portion134_2includes a pair of extension walls134cand134dprotruding and extending laterally from the outer side walls133aand133bso as to be disposed with the other outer leg interposed therebetween.

When the third core110and the first base130are assembled with each other, the center leg of the third core110is inserted into the through-hole131ain the third-coil-seating portion131, and the pair of outer legs of the third core110is located in the outer-leg-slot portions134_1and134_2, respectively, whereby the third-coil-seating portion131is disposed in the third core110.

A first coil hole137aand a third coil hole173binto which both end portions of the flat wire coil of the third coil120are inserted are formed in one side of the first base130.

The flat wire coil forming the third coil120passes through the first coil hole137afrom below to above, is bent horizontally to enter an upper portion in the third core110, is spirally wound around the center leg of the third core110in the downward direction, and then is seated on the bottom of the third-coil-seating portion131. Subsequently, the flat wire coil passes through the path slot133cin the outer side wall133b, is bent upward, makes a U-turn to extend downward, and then is inserted into the third coil hole173b.

Meanwhile, the first base130includes a fastening portion139extending horizontally from one side of the third-coil-seating portion131and including a fastening hole139afor fastening of a screw or the like.

As shown inFIG.9, the second base160includes fourth-core-seating portions161,161a,162, and162a, on which the fourth core140is seated and supported.

The fourth-core-seating portions161,161a,162, and162ainclude a pair of vertical walls161and162disposed with the fourth core140interposed therebetween, and seating protrusions161aand162aprotruding from the lower ends of the respective vertical walls to allow the fourth core140to be seated and supported thereon.

In addition, the second base160includes a fourth-coil-seating portion163, which penetrates the fourth core140and is formed to interconnect the pair of vertical walls161and162and on which the fourth coil150is seated.

In the second base160, coil-receiving recesses161band162bin which end portions of the fourth coil150are received are formed in the outer surfaces of the respective vertical walls.

The fourth coil150is made using a flat wire coil, and is seated and supported on the fourth-coil-seating portion163. Both sides of the fourth coil150are bent downward to be received in the coil-receiving recesses161band162b, respectively, and extend downward.

Third Embodiment of Output Inductor and EMI Inductor

FIGS.10to12show a third embodiment of the output inductor and the EMI inductor, which will be described below.

In this embodiment, the structures of a third core210and a fourth core240are the same as those in the first embodiment, and therefore, detailed description thereof will be omitted.

In this embodiment, the third core210and the fourth core240are disposed so as to overlap each other in the horizontal direction (the second direction). However, unlike the first and second embodiments in which the penetration direction of the through-hole in the third core and the penetration direction of the through-hole in the fourth core are perpendicular to each other, this embodiment is configured such that the penetration direction of a through-hole in the third core210and the penetration direction of a through-hole in the fourth core240are parallel to each other.

In this embodiment, a third coil220and a fourth coil250are continuously and integrally formed, similar to the first embodiment.

Similar to the second embodiment, a base is of a separation type, and includes a first base230and a second base260.

First, the first base230will be described in detail with reference toFIG.13.

The first base230includes a third-coil-seating portion231, in which a through-hole231ais formed to allow a center leg of the third core210to pass therethrough and a flat surface is formed around the through-hole231ato allow the third coil220to be seated thereon.

An inner side wall232is formed on the inner circumference of the third-coil-seating portion231so as to surround the through-hole231a, and outer side walls233aand233bare formed on the outer circumference of the third-coil-seating portion231.

A path slot233cis formed in one side of the outer side wall233bso that the flat wire coil escaping from the third core210after being spirally wound in the downward direction in the third core210passes through the outer side wall233b.

Outer-leg-slot portions234_1and234_2in which a pair of outer legs of the third core210is located are formed in both sides of the third-coil-seating portion231.

In addition, the outer-leg-slot portions234_1and234_2include extension walls234a,234b,234c, and234dextending laterally from the outer side walls233aand233b.

That is, as shown inFIG.8, the first outer-leg-slot portion234_1includes a pair of extension walls234aand234bprotruding and extending laterally from the outer side walls233aand233bso as to be disposed with one outer leg interposed therebetween. In addition, the second outer-leg-slot portion234_2includes a pair of extension walls234cand234dprotruding and extending laterally from the outer side walls233aand233bso as to be disposed with the other outer leg interposed therebetween.

When the third core210and the first base230are assembled with each other, the center leg of the third core210is inserted into the through-hole231ain the third-coil-seating portion231, and the pair of outer legs of the third core210is located in the outer-leg-slot portions234_1and234_2, respectively, whereby the third-coil-seating portion231is disposed in the third core210.

A first coil hole237ainto which one end portion of the flat wire coil of the third coil220is inserted is formed in one side of the first base230.

As shown inFIG.14, the second base260includes fourth-core-seating portions261,261a,262, and262a, on which the fourth core240is seated and supported.

The fourth-core-seating portions261,261a,262, and262ainclude a pair of vertical walls261and262disposed with the fourth core240interposed therebetween, and seating protrusions261aand262aprotruding from the lower ends of the respective vertical walls261and262to allow the fourth core240to be seated and supported thereon.

In addition, the second base260includes a fourth-coil-seating portion263, which penetrates the fourth core240and is formed to interconnect the pair of vertical walls261and262and on which the fourth coil250is seated.

In the second base260, a coil-receiving recess262bin which an end portion of the fourth coil250is received is formed in the outer surface of the vertical wall262. In addition, a pin portion264, which further extends from the fourth-coil-seating portion263and includes a pin hole264a, is formed on the outer surfaces of the other vertical walls261and262. The pin portion264includes a curved portion264bformed on an edge of the upper end thereof to guide bending of the coil, which will be described later.

Due to the above-described structures of the first base230and the second base260, the flat wire coil forming the third coil220passes through the first coil hole237afrom below to above, is bent horizontally to enter an upper portion in the third core210, is spirally wound around the center leg of the third core210in the downward direction, and then is seated on the bottom of the third-coil-seating portion231. Subsequently, the flat wire coil passes through the path slot233cin the outer side wall233b, is bent upward, and then is bent horizontally to be placed on the pin portion264and to be seated and supported on the fourth-coil-seating portion263. Subsequently, the flat wire coil passes through the fourth core240, is bent downward to be received in the coil-receiving recess262b, and extends downward.

Fourth Embodiment of Output Inductor and EMI Inductor

FIGS.15and16show a fourth embodiment of the output inductor and the EMI inductor, which will be described below.

In this embodiment, the structures of a third core310and a fourth core340are the same as those in the first embodiment, and therefore, detailed description thereof will be omitted.

In this embodiment, the third core310and the fourth core340are disposed so as to overlap each other in the horizontal direction (the second direction). However, in this embodiment, the penetration direction of a through-hole in the third core310and the penetration direction of a through-hole in the fourth core340form a predetermined angle (about 45 degrees) therebetween.

In this embodiment, a third coil320and a fourth coil350are continuously and integrally formed, similar to the first embodiment.

This embodiment includes a first base330and a bracket360, the structures of which will be described below in detail with reference toFIGS.18and19.

The first base330includes a third-coil-seating portion331, in which a through-hole331ais formed to allow a center leg of the third core310to pass therethrough and a flat surface is formed around the through-hole331ato allow the third coil320to be seated and supported thereon.

In addition, the first base330includes a protruding portion338, which is formed on one side of the third-coil-seating portion331so as to protrude to a height lower than the thickness of the flat wire coil of the third coil320. Here, the protruding portion338includes a coil path slot338aformed in one side thereof to allow the coil escaping from the third core310to pass therethrough.

The third coil320is placed on the upper surface of the fourth core340before entering the third core310. The bracket360is formed so as to surround the upper surface and both side surfaces of the fourth core340in the state in which the third coil320is disposed on the fourth core340.

The bracket360may have a shape in which a thin metal strip is bent, and includes an upper strip portion361and side strip portions362and363bent and extending from both sides of the upper strip portion361to be formed in a substantially U-shape.

Here, the upper strip portion361includes a protruding receiving portion361aformed on one side thereof so as to protrude upward. The third coil320is placed on the upper surface of the fourth core340, is received in the protruding receiving portion361a, and is fixed by the bracket360.

In this embodiment, the flat wire coil forming the third coil320is placed on the fourth core340, is received in the protruding receiving portion361a, enters an upper portion in the third core310at the same height, is spirally wound around the center leg of the third core310in the downward direction, and then is seated on the bottom of the third-coil-seating portion331. Subsequently, the flat wire coil passes through the path slot338a, is bent upward, and then is bent horizontally to penetrate the fourth core340.

Here, as shown inFIG.15, the end portion of the fourth coil350may increase in planar area to include a bus bar structure including a through-hole formed in the center thereof.

Embodiment of ZVS Inductor and Transformer

FIGS.20to22show an embodiment of the ZVS inductor and the transformer according to the present disclosure, which will be described below.

In this embodiment, the transformer is a ZVS-inductor-integrated transformer with which the ZVS inductor is integrally formed.

A first core70is formed in such a manner that an upper core portion71and a lower core portion72contact each other, and has the same shape as the third core10in the first embodiment, and therefore, detailed description thereof will be omitted.

Further, a second core80has substantially the same shape as the upper core portion71of the first core70.

In this embodiment, the second core80is disposed above the first core70, and the second core80and the first core70overlap each other in the vertical direction (the first direction).

A first coil73is disposed in the first core70so as to be wound around a center leg of the first core70to form a primary coil73, and a secondary coil74is disposed in the first core70so as to surround the center leg in a state of being separated and electrically isolated from the primary coil73.

In this embodiment, the secondary coil74is implemented as a plurality of conductive plates, but the disclosure is not limited thereto.

The first coil73, which constitutes the primary coil73, enters a lower portion in the first core70, is spirally wound in the upward direction, and then escapes from the first core70. Subsequently, the first coil73enters the second core80, is wound around the center leg of the second core80, and then escapes from the second core80.

That is, in this embodiment, the first coil73and a second coil81are integrally formed in such a manner that a single coil wire is continuously wound.

In this embodiment, a bobbin or a base structure, which is a plastic injection-molded product for electrical isolation between the primary coil73and the secondary coil74, is omitted from the transformer.

A more compact structure may be realized through omission of a bobbin or a base structure.

MODE FOR INVENTION

Various embodiments have been described in the best mode for carrying out the disclosure.