Magnetic element and circuit board including the same

Abstract

The present invention relates to a slimmable magnetic element and a circuit board including the same. An EMI filter according to one embodiment includes a core unit including an upper core and a lower core, and a coil unit partially disposed within the core unit and including a first coil unit and a second coil unit, wherein the first coil unit includes a first substrate, a first upper conductive pattern disposed on an upper surface of the first substrate, and a first lower conductive pattern disposed on a bottom surface of the first substrate, and the second coil unit includes a second substrate, a second upper conductive pattern disposed on an upper surface of the second substrate, and a second lower conductive pattern disposed on the bottom surface of the second substrate, and the coil unit includes the first upper conductive pattern, the first lower conductive pattern, and the second upper conductive pattern. a primary pattern lead-out portion disposed on one side of the central portion, where one ends of the first upper conductive pattern and the first lower conductive pattern are led out from the central portion; and a second pattern lead-out portion disposed on the other side of the central portion, where one ends of the second upper conductive pattern and the second lower conductive pattern are led out from the central portion, and within the second pattern lead-out portion, the second upper conductive pattern and the second lower conductive pattern may be overlapped in a vertical direction so that at least a portion of the second upper conductive pattern and the second lower conductive pattern intersect on a plane.

Description

[Technical Field]

[0001] The present invention relates to a magnetic element that can be slimmed down and a circuit board including the same. [Background technology]

[0002] Magnetic elements are also called magnetic coupling devices, and typical examples include EMI filters that combine an inductor and a transformer, or an inductor and a capacitor. Such magnetic elements can be mounted on various types of circuit boards. However, when configuring an EMI filter for the power supply of an electronic product, the layout of the circuit can be an issue depending on the operating mode. This will be explained with reference to Figure 1.

[0003] FIG. 1 is a circuit diagram showing a part of the EMI filter configuration.

[0004] Although not shown, an EMI filter is an inductor and capacitor connected to the circuit board, i.e., power board, of an electronic product, and serves to pass signals necessary for circuit operation while filtering out noise. Here, noise transmitted from the power board can be broadly divided into radiated noise and conducted noise transmitted through the power line.

[0005] Conductive noise transmission methods can be divided into differential mode and common mode. Of these, common mode noise, even a small amount, returns in a large loop, affecting electronic devices located far away. This common mode noise can also be generated by impedance imbalance in the wiring system, and is more pronounced in high-frequency environments. To eliminate this common mode noise, as shown in Figure 1(a), the input lines of the primary coil L1 and secondary coil L2 in the EMI filter must be connected with the same polarity. This is because magnetic flux reinforcement occurs inside the magnetic core when common mode noise is applied.

[0006] However, in response to the recent trend toward slimmer electronic products, slim EMI filters have become popular, in which the primary coil L1 and secondary coil L2 each have the form of a printed circuit board (PCB) and share the center leg of the magnetic core. In such slim EMI filters, the design of the circuit board to meet the demand for slimness can sometimes result in opposite polarities being connected to the input lines of the primary coil L1 and secondary coil L2, as shown in Figure 1(b).

[0007] Therefore, when using a slim type EMI filter, in order to connect the same polarity to the input lines of the primary coil L1 and the secondary coil L2, the configuration of the existing circuit board must be changed accordingly, which increases the difficulty of design compared to a board pattern designed for optimized efficiency and may even result in a decrease in the efficiency of the power supply itself. Summary of the Invention [Problem to be solved by the invention]

[0008] The technical problem to be solved by the present invention is to provide a slim EMI filter and a circuit board that can be further slimmed down without affecting the structure of the circuit board.

[0009] The technical problems to be achieved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0010] An EMI filter according to an embodiment includes a core unit including an upper core and a lower core, and a coil unit partially disposed within the core unit and including a first coil unit and a second coil unit, wherein the first coil unit includes a first substrate, a first upper conductive pattern disposed on an upper surface of the first substrate, and a first lower conductive pattern disposed on a bottom surface of the first substrate, and the second coil unit includes a second substrate, a second upper conductive pattern disposed on an upper surface of the second substrate, and a second lower conductive pattern disposed on the bottom surface of the second substrate, and the coil unit includes the first upper conductive pattern, the first lower conductive pattern, and the second upper conductive pattern. a primary pattern lead-out portion disposed on one side of the central portion, where one ends of the first upper conductive pattern and the first lower conductive pattern are led out from the central portion; and a second pattern lead-out portion disposed on the other side of the central portion, where one ends of the second upper conductive pattern and the second lower conductive pattern are led out from the central portion, and within the second pattern lead-out portion, the second upper conductive pattern and the second lower conductive pattern may be overlapped in a vertical direction so that at least a portion of the second upper conductive pattern and the second lower conductive pattern intersect on a plane.

[0011] For example, each of the first upper conductive pattern, the first lower conductive pattern, the second upper conductive pattern, and the second lower conductive pattern may have a spiral planar shape.

[0012] For example, the first upper conductive pattern may have a spiral planar shape rotating in a first direction on a plane, and one of the second upper conductive pattern and the second lower conductive pattern may have a spiral planar shape rotating in the first direction on a plane.

[0013] For example, the first lower conductive pattern may have a spiral planar shape rotating in a second direction opposite to the first direction on a plane, and the other of the second upper conductive pattern and the second lower conductive pattern may have a spiral planar shape rotating in the second direction on a plane.

[0014] For example, the other ends of the first upper conductive pattern and the first lower conductive pattern may be electrically connected to each other through a first via hole that penetrates the first substrate, and the other ends of the second upper conductive pattern and the second lower conductive pattern may be electrically connected to each other through a second via hole that penetrates the second substrate.

[0015] For example, the first upper conductive pattern and the first lower conductive pattern may be spaced apart from each other in the primary pattern lead-out portion on a plane.

[0016] For example, the length of the second upper conductive pattern and the length of the second lower conductive pattern within the second pattern leading portion may be the same.

[0017] For example, the deviation between the sum of the first length of the first upper conductive pattern and the first lower conductive pattern and the sum of the second length of the second upper conductive pattern and the second lower conductive pattern may be within 5%.

[0018] For example, the deviation between the sum of the third lengths of the first upper conductive pattern and the first lower conductive pattern in the primary pattern lead-out portion and the sum of the fourth lengths of the second upper conductive pattern and the second lower conductive pattern in the second pattern lead-out portion may be within 5%.

[0019] For example, at least one of the first upper conductive pattern and the first lower conductive pattern in the primary pattern extraction portion may have a curved planar shape having a curvature at a point where the first upper conductive pattern and the first lower conductive pattern are closest to each other on a plane.

[0020] For example, within the primary pattern lead-out portion, at least one of the first upper conductive pattern and the first lower conductive pattern may have an apex forming an inflection at a point where the first upper conductive pattern and the first lower conductive pattern are closest to each other on a plane, and a bridge portion disposed around the apex.

[0021] A circuit board according to an embodiment of the present invention comprises: A substrate; The EMI filter includes a circuit unit formed on the substrate, and an EMI filter electrically connected to the circuit unit, the EMI filter including an inductor and a capacitor, the inductor including a core unit including an upper core and a lower core, and a coil unit partially disposed within the core unit and including a first coil unit and a second coil unit, the first coil unit including a first substrate, a first upper conductive pattern disposed on an upper surface of the first substrate, and a first lower conductive pattern disposed on a bottom surface of the first substrate, the second coil unit including a second substrate, a second upper conductive pattern disposed on the upper surface of the second substrate, and a second lower conductive pattern disposed on the bottom surface of the second substrate, the coil unit being a primary pattern lead-out portion disposed on one side of the central portion, where one ends of the first upper conductive pattern and the first lower conductive pattern are led out from the central portion; and a second pattern lead-out portion disposed on the other side of the central portion, where one ends of the second upper conductive pattern and the second lower conductive pattern are led out from the central portion, and within the second pattern lead-out portion, the second upper conductive pattern and the second lower conductive pattern may be vertically overlapped so that at least a portion of the second upper conductive pattern and the second lower conductive pattern intersect on a plane.

[0022] For example, the first upper conductive pattern and the first lower conductive pattern may be spaced apart from each other in the primary pattern lead-out portion on a plane.

[0023] For example, the deviation between the sum of the first length of the first upper conductive pattern and the first lower conductive pattern and the sum of the second length of the second upper conductive pattern and the second lower conductive pattern may be within 5%.

[0024] For example, the deviation between the sum of the third lengths of the first upper conductive pattern and the first lower conductive pattern in the primary pattern lead-out portion and the sum of the fourth lengths of the second upper conductive pattern and the second lower conductive pattern in the second pattern lead-out portion may be within 5%. [Effects of the Invention]

[0025] In the EMI filter and the circuit board including the same according to the embodiment, at least one coil portion has a cross pattern, so that it is easy to match the connection polarity of the primary coil and the secondary coil.

[0026] In addition, if both coil portions of the EMI filter have cross patterns, there is no problem with inductance deviation even if the filter is placed independently on the circuit board.

[0027] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a circuit diagram showing a part of the configuration of an EMI filter. [Figure 2] FIG. 1 is a perspective view of an EMI filter according to an embodiment. [Figure 3] FIG. 1 is an exploded perspective view of an EMI filter according to an embodiment. [Figure 4a-4b]FIG. 2 is a diagram illustrating an example of the configuration of a primary coil section according to an embodiment. [Figure 5a-5b] FIG. 3 is a diagram illustrating an example of the configuration of a secondary coil section according to an embodiment. [Figure 6] FIG. 2 is a plan view showing an example of the configuration of a coil unit according to an embodiment. [Figure 7] 10A and 10B are diagrams for explaining the effect of the crossing pattern of the secondary coil section according to one embodiment. [Figure 8] FIG. 1 is a diagram illustrating an example of a concept of a circuit configuration using an EMI filter according to an embodiment. [Figure 9] FIG. 10 is a plan view showing an example of the configuration of a coil portion according to another embodiment. [Figure 10] FIG. 10 is a plan view showing another example of the configuration of the coil portion according to another embodiment. [Figure 11] FIG. 10 is a diagram showing yet another example of the configuration of a coil portion according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0029] Although the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described with reference to the drawings. However, it should be understood that this is not intended to limit the present invention to the specific embodiments, and that the present invention includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention.

[0030] Terms including ordinal numbers such as "second," "first," etc. may be used to describe various elements, but the elements are not limited by these terms. These terms are used solely to distinguish one element from another. For example, a second element may be referred to as a first element, and similarly, a first element may be referred to as a second element, without departing from the scope of the present invention. The term "and / or" includes a combination of multiple related listed items or any of multiple related listed items.

[0031] When a component is said to be "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that there may be additional components in between. On the other hand, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no additional components in between.

[0032] In the description of the embodiments, when a layer (film), region, pattern, or structure is described as being "on" or "under" a substrate, layer (film), region, pad, or pattern, this includes those formed directly or with other layers interposed therebetween. The reference to "on" or "under" each layer is based on the drawings. In addition, the thickness and size of each layer (film), region, pattern, or structure in the drawings may be modified for clarity and convenience of description and do not necessarily reflect the actual size.

[0033] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as idealized or overly formal unless expressly defined in this application.

[0035] Hereinafter, in a detailed description of the embodiments based on the accompanying drawings, the same or corresponding components are denoted by the same reference numerals regardless of the drawing number, and redundant description thereof will be omitted. In addition, some embodiments are described using a coordinate system, and in the coordinate system, the first, second, and third axes shown in each drawing are orthogonal to each other, but the embodiments are not limited thereto. The first, second, and third axes may also intersect each other.

[0036] Hereinafter, the EMI filter according to the present embodiment will be described in detail with reference to the accompanying drawings.

[0037] FIG. 2 is a perspective view of an EMI filter according to an embodiment, and FIG. 3 is an exploded perspective view of the EMI filter according to an embodiment.

[0038] 2 and 3, an EMI filter 100 according to an embodiment may include a core portion 110 and coil portions 120 and 130. Each component will be described in detail below.

[0039] The core units 111 and 112 have magnetic circuit characteristics and can serve as a magnetic flux path. The core units 111 and 112 may include an upper core 111 joined at the top and a lower core 112 joined at the bottom. The two cores 111 and 112 may be vertically symmetrical or asymmetrical to each other, or one of the upper core 111 and the lower core 112 may be removed. However, for the convenience of explanation, the following disclosure will be assumed to be vertically symmetrical.

[0040] 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, and CL2 that protrude from the body portion in a first direction (i.e., one axial direction) and extend along a predetermined direction. For example, the plurality of leg portions OL1-1, OL1-2, and CL1 of the upper core 111 may include two outer leg portions OL1-1 and OL1-2 that are spaced apart from each other along a second direction (i.e., two axial directions) that intersects the first direction on a plane, and one middle leg portion CL1 that is disposed between the two outer leg portions OL1-1 and OL1-2. Furthermore, each of the plurality of leg portions OL1-1, OL1-2, OL2-1, OL2-2, CL1, and CL2 may extend along a third direction (i.e., three axial directions) that intersects the first and second directions on a plane.

[0041] When the upper core 111 and the lower core 112 are joined together, the outer legs OL1-1, OL1-2 and the middle leg CL1 of the upper core 111 face the corresponding outer legs OL2-1, OL2-2 and the middle leg CL2 of the lower core 112. The opposing outer leg pair OL1-1, OL2-1 on one side can be called a first outer leg portion, the opposing outer leg pair OL1-2, OL2-2 on the other side can be called a second outer leg portion, and the middle leg pair CL1, CL2 can be called a middle leg portion.

[0042] A gap of a predetermined distance (for example, 10 to 200 μm, but not limited thereto) may be formed between at least some of the opposing outer leg pairs and middle leg pairs. The inductance of the core part 110 can be controlled by adjusting the size of the gap between one middle leg pair and two outer leg pairs, and heat generation can be controlled by adjusting the number of gaps.

[0043] Additionally, the core portion 110 may include a magnetic material such as, but not limited to, iron or ferrite.

[0044] Since the core portion 110 surrounds a portion of the coil portions 120 and 130 , it can be considered that a portion of each of the primary coil portion 120 and the secondary coil portion 130 that constitute the coil portions 120 and 130 is disposed within the core portion 110 .

[0045] The primary coil unit 120 and the secondary coil unit 130 have a first through hole TH1 and a second through hole TH2 at their centers, respectively, and the middle legs CL1 and CL2 of the core unit 110 may pass through the first through hole TH1 and the second through hole TH2. That is, the first through hole TH1 and the second through hole TH2 allow the primary coil unit 120 and the secondary coil unit 130 to be aligned on a plane centered on the middle legs CL1 and CL2.

[0046] Primary coil section 120 and secondary coil section 130 Each of the conductive patterns may have a configuration in which a conductive pattern is printed to form a plurality of turns on the top and bottom surfaces of a flat substrate having a rectangular planar shape.

[0047] The configurations of the primary coil section 120 and the secondary coil section 130 will be described in more detail with reference to FIGS. 4a to 5b.

[0048] 4a and 4b show an example of the configuration of the primary coil section according to one embodiment.

[0049] 4a shows a side view of primary coil portion 120 in the center, a plan view of first upper conductive pattern 121 at the top, and a plan view of first lower conductive pattern 123 at the bottom. Also, in FIG. 4b, a plan view of the primary coil portion is shown, but for ease of understanding, first upper conductive pattern 121 and first lower conductive pattern 123 are shown overlapping on a plane.

[0050] Referring to Figures 4a and 4b, the primary coil part 120 may include a first substrate 122, a first upper conductive pattern 121 disposed on the upper surface of the first substrate 122, and a first lower conductive pattern 123 disposed on the bottom surface of the first substrate 122.

[0051] Each of the first upper conductive pattern 121 and the first lower conductive pattern 123 has a spiral planar shape and may have a plurality of turns.

[0052] One end 121-1 of the first upper conductive pattern 121 is disposed on an edge side of the substrate 122, and the other end 121-2 is disposed at the innermost side of the spiral pattern. That is, the first upper conductive pattern 121 may extend from one end 121-1 on the edge side of the substrate 122 along the longitudinal axis direction of the substrate (i.e., the third direction), and then extend from the outer side to the inner side to the other end 121-2 in a spiral pattern.

[0053] One end 123-1 of the first lower conductive pattern 123 is disposed on the edge side of the substrate 122, and the other end 123-2 is disposed on the innermost side of the spiral pattern.

[0054] In addition, the spiral patterns of the first upper conductive pattern 121 and the first lower conductive pattern 123 may have opposite rotation directions. For example, the first upper conductive pattern 121 may have a spiral pattern extending from one end 121-1 to the other end 121- 2 to The first lower conductive pattern 123 has a spiral pattern that rotates counterclockwise from one end 123-1 to the other end 123- 2 to It may have a spiral pattern that rotates in a clockwise direction.

[0055] Here, the other end 121-2 of the first upper conductive pattern 121 and the other end 123-2 of the first lower conductive pattern 123 may at least partially overlap on a plane and be electrically connected through a via hole penetrating the substrate 122.

[0056] Since the first lower conductive pattern 123 is electrically connected through the via holes and has spiral patterns with opposite rotation directions, when one end 123-1 of the first lower conductive pattern 123 becomes the input end of the primary current and one end 121-1 of the first upper conductive pattern 121 becomes the output end of the primary current, the primary current flows uniformly in one direction (i.e., clockwise) within the primary coil portion 120.

[0057] Meanwhile, one end 121-1 of the first upper conductive pattern 121 and one end 123-1 of the first lower conductive pattern 123 are spaced apart from each other in the shortening direction (i.e., the second direction or the two-axis direction) of the substrate 122, but may have the same length extending along the long axis direction (i.e., the third direction or the three-axis direction) of the substrate 122.

[0058] 5a and 5b show an example of the configuration of the secondary coil section according to one embodiment.

[0059] 5a, a side view of secondary coil portion 130 is shown in the center, a plan view of second upper conductive pattern 131 is shown at the top, and a plan view of second lower conductive pattern 133 is shown at the bottom, similar to Fig. 4a. Also, Fig. 5b shows a plan view of the secondary coil portion, but for ease of understanding, second upper conductive pattern 131 and second lower conductive pattern 133 are shown overlapping on a plane.

[0060] Referring to Figures 5a and 5b, the secondary coil part 130 may include a second substrate 132, a second upper conductive pattern 131 arranged on the upper surface of the second substrate 132, and a second lower conductive pattern 133 arranged on the bottom surface of the second substrate 132.

[0061] The second upper conductive pattern 131 and the second lower conductive pattern 133 each have a spiral planar shape and may have a plurality of turns.

[0062] One end 131-1 of the second upper conductive pattern 131 is disposed on the edge of the substrate 132, and the other end 131-2 is disposed on the innermost side of the spiral pattern. Here, the second upper conductive pattern 131 extends from one end 131-1 on the edge of the substrate 132 and then extends from the outside to the inside. Heading to The wire 131 may extend in a spiral pattern in the opposite direction to the other end 131-2.

[0063] In addition, one end 133-1 of the second lower conductive pattern 133 is disposed on the edge side of the substrate 132, and the other end 133-2 is disposed on the innermost side of the spiral pattern.

[0064] The spiral patterns of the second upper conductive pattern 131 and the second lower conductive pattern 133 may have opposite rotation directions. For example, the second upper conductive pattern 131 has a spiral pattern that rotates counterclockwise from one end 131-1 to the other end 131-2, and the second lower conductive pattern 133 has a spiral pattern that rotates counterclockwise from one end 133-1 to the other end 133-2. Heading to The pattern may have a spiral shape that rotates clockwise.

[0065] Here, the other end 131-2 of the second upper conductive pattern 131 and the other end 133-2 of the second lower conductive pattern 133 may at least partially overlap on a plane and be electrically connected through a via hole penetrating the substrate 132.

[0066] By being electrically connected through such via holes and having spiral patterns with opposite rotation directions, when one end 133-1 of the second lower conductive pattern 133 becomes the input end of the secondary current and one end 131-1 of the second upper conductive pattern 131 becomes the output end of the secondary current, the secondary current flows uniformly in one direction (i.e., clockwise) within the secondary coil part 130.

[0067] Meanwhile, one end 131-1 of the second upper conductive pattern 131 and one end 131-2 of the second lower conductive pattern 133 oneThe ends 133-1 may be spaced apart from each other in the shortening direction (i.e., the second direction or the biaxial direction) of the substrate 132. Here, the first upper conductive pattern 1 2 One end of 1 2 1-1 and the first lower conductive pattern 1 2 One end of 3 2 3-1 extend straight along the third direction, whereas one end 131-1 of the second upper conductive pattern 131 and one end 133-1 of the second lower conductive pattern 133 extend along the third direction, then extend in the opposite direction along the second direction, and then extend to form a turn. Therefore, the second upper conductive pattern 131 and the second lower conductive pattern 133 at least partially overlap each other in a plane before forming a turn. In other words, the second upper conductive pattern 131 and the second lower conductive pattern 133 have portions that intersect with each other in a plane before forming a turn. Therefore, it can be said that the second upper conductive pattern 131 and the second lower conductive pattern 133 of the secondary coil unit 130 have a "cross pattern."

[0068] FIG. 6 is a plan view showing an example of the configuration of the coil section according to one embodiment.

[0069] FIG. 6 shows a shape in which the primary coil section 120 and the secondary coil section 130 overlap each other on a plane.

[0070] Referring to FIG. 6, the coil units 120 and 130 may include a central portion PC, which is a portion where the first upper conductive pattern 121, the first lower conductive pattern 123, the second upper conductive pattern 131, and the second lower conductive pattern 133 each form a turn, a primary pattern lead-out portion P1 located on one side of the central portion PC along the longitudinal axis direction (i.e., the third or third axis direction) of the coil units 120 and 130, and a secondary pattern lead-out portion P2 located on the other side of the central portion PC along the longitudinal axis direction of the coil units 120 and 130.

[0071] It is preferable that the length L1 of the primary pattern lead portion P1 and the length L2 of the secondary pattern lead portion P2 along the third direction are the same, but this is merely an example and the length L1 of the primary pattern lead portion P1 and the length L2 of the secondary pattern lead portion P2 may be different.

[0072] For example, the length of the first upper conductive pattern 121 and the length of the first lower conductive pattern 123 within the primary pattern leading portion P1 may be the same.

[0073] Additionally, the length of the second upper conductive pattern 131 and the length of the second lower conductive pattern 133 within the secondary pattern leading portion P2 may be the same.

[0074] Meanwhile, in FIG. 6, the second upper conductive pattern 131 and the second lower conductive pattern 133 are shown as being symmetrical to each other along the second direction within the secondary pattern lead-out portion P2 to form an "X"-shaped cross pattern, but this is merely an example and does not necessarily mean that they must be symmetrical within the secondary pattern lead-out portion P2.

[0075] The effect achieved by having the configurations of the coil sections 120 and 130 described with reference to FIGS. 4 to 6 will be described with reference to FIG.

[0076] FIG. 7 is a diagram for explaining the effect of the crossing pattern of the secondary coil portion according to one embodiment.

[0077] In FIG. 7, a plan view of the primary coil section 120 is shown at the top, and a plan view of the secondary coil section 130 is shown at the bottom.

[0078] 7, similar to (a) of FIG. 1, a situation is assumed in which one end 123-1 of the primary lower conductive pattern 123 is the primary input end, one end 121-1 of the first upper conductive pattern 121 is the primary output end, one end 133-1 of the second lower conductive pattern 133 is the secondary input end, and one end 131-1 of the second upper conductive pattern 131 is the secondary output end.

[0079] In this case, as shown in Fig. 7, the primary current and the secondary current flow in the same direction (here, clockwise). Therefore, when the EMI filter 100 functions as a common mode choke, the input lines of the primary coil L1 and the secondary coil L2 can be connected with the same polarity, as in the case of an existing circuit board configuration. As a result, when applied to the EMI filter 100 according to the embodiment, a circuit board configuration in the form of existing general conductive wire windings can be configured.

[0080] In the embodiments described so far, only the lead-out portion of the secondary coil unit 130 has a cross pattern. 2 Only the 0 lead may have a cross pattern.

[0081] FIG. 8 shows an example of the concept of a circuit configuration using an EMI filter according to an embodiment.

[0082] In the EMI filter 100 according to one embodiment, the length of the conductive pattern within the pattern lead-out portion of one of the primary coil portion 120 and the secondary coil portion 130, which has a cross pattern, is longer than the remaining coil portions without a cross pattern. Therefore, the inductance of the one coil portion with a cross pattern is relatively high, which can result in inductance asymmetry between the primary and secondary coils. This can act as an additional heat generation channel when the magnetic element is driven, reducing the efficiency of the magnetic element. To address this issue, as shown in FIG. 8, when an even number of EMI filters 100A and 100B according to the embodiment are arranged in series, the combined inductance of the entire circuit board can be symmetrical. That is, by arranging the input and output terminals of each EMI filter 100A and 100B in series so that they are symmetrical, inductance can be matched.

[0083] Meanwhile, in another embodiment of the present invention, a solution is proposed for solving the inductance asymmetry caused by the cross pattern within a single EMI filter.

[0084] 9 to 11 are plan views showing examples of the configuration of the coil portion according to other embodiments.

[0085] 9 to 11 show the primary coil section 120' and the secondary coil section 130 overlapping each other on a plane.

[0086] Referring to FIG. 9, the secondary coil unit 130 of the coil units 120′ and 130 according to another embodiment has the same configuration as that described with reference to FIG. 5. Unlike the configuration shown in FIG. 4, the first upper conductive pattern 121′ and the first lower conductive pattern 123′ constituting the primary coil unit 120′ do not extend straight in the third direction within the primary pattern extension portion P1, but are curved or folded into a predetermined shape and connected to the center portion PC. Here, the point of the curved fold may be the point where the first upper conductive pattern 121′ and the first lower conductive pattern 123′ are closest in plan view. When folded, the conductive patterns may have a vertex that forms an inflection. Here, the planar shapes of the first upper conductive pattern 121′ and the first lower conductive pattern 123′ within the primary pattern extension portion P1 are shown as being similar and symmetrical to the second upper conductive pattern 131 and the second lower conductive pattern 133 within the secondary pattern extension portion P2. However, this is merely an example, and the conductive patterns located in the primary pattern lead-out portion P1 and the secondary pattern lead-out portion P2 do not necessarily have to be symmetrical. However, for inductance matching, it is preferable that the overall lengths of the first upper conductive pattern 121' and the first lower conductive pattern 123' are the same as the overall lengths of the second upper conductive pattern 131 and the second lower conductive pattern 133. Here, even if the deviation between the overall lengths of the first upper conductive pattern 121' and the first lower conductive pattern 123' and the overall lengths of the second upper conductive pattern 131 and the second lower conductive pattern 133 is within 5%, it has been confirmed that there is no significant impact on the efficiency of the magnetic element, and therefore the overall lengths can be considered to be included in the same concept. However, if the deviation between the respective overall lengths is within 3%, more preferably within 1%, the difference in inductance can be made smaller, making fine tuning of inductance matching easier. For example, in the central portion PC, the first upper conductive pattern 121', the first lower conductive pattern 123', the second upper conductive pattern 131, and the second lower conductive pattern 133 may have the same length.In this case, the sum of the length of the first upper conductive pattern 121′ and the length of the first lower conductive pattern 123′ in the primary pattern lead-out portion P1 may be the same as the sum of the length of the second upper conductive pattern 131 and the length of the second lower conductive pattern 133 in the secondary pattern lead-out portion P2.

[0087] In addition, in the secondary pattern lead-out portion P2, the second upper conductive pattern 131 and the second lower conductive pattern 133 form a cross pattern in which at least a portion of them overlap along the first direction on a plane, while in the primary pattern lead-out portion P1, the first upper conductive pattern 121' and the first lower conductive pattern 123' may be spaced apart without overlapping each other along the first direction on a plane.

[0088] 10 showing another embodiment, in the primary pattern extension portion P1, the first upper conductive pattern 121′ and the first lower conductive pattern 123′ do not overlap each other in the first direction on a plane, and within the range where the overall lengths of the first upper conductive pattern 121′ and the first lower conductive pattern 123′ are the same as the overall lengths of the second upper conductive pattern 131 and the second lower conductive pattern 133, at least one of the first upper conductive pattern 121′ and the first lower conductive pattern 123′ in the primary pattern extension portion P1 may be embodied in a curved shape having a curvature in one of their respective bending regions. For example, at least one of the first upper conductive pattern 121′ and the first lower conductive pattern 123′ may be applied so that the shape of the vertex region nearest to each other is curved.

[0089] 11, in the primary pattern extension portion P1, the first upper conductive pattern 121' and the first lower conductive pattern 123' do not overlap each other in the first direction on a plane, and within the range in which the overall lengths of the first upper conductive pattern 121' and the first lower conductive pattern 123' are the same as the overall lengths of the second upper conductive pattern 131 and the second lower conductive pattern 133, at least one of the first upper conductive pattern 121' and the first lower conductive pattern 123' in the primary pattern extension portion P1 may form a bridge portion between the patterns forming each vertex in the region of the vertex that is closest to each other, thereby increasing the area. For example, the bridge portion may be arranged around the vertex forming the inflection to fill at least a portion of the space between two sides extending from the vertex. This may facilitate the flow of charges in this region.

[0090] The above description has been given based on the embodiments, but these are merely examples and are not intended to limit the present invention. Those skilled in the art will recognize that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the present embodiments. For example, each component specifically illustrated in the embodiments can be modified and implemented. Differences related to such modifications and applications should be interpreted as being included within the scope of the present invention as defined in the appended claims.

Claims

1. a core portion including an upper core and a lower core; a coil portion, the coil portion being partially disposed within the core portion and including a first coil portion and a second coil portion; the first coil unit includes a first substrate, a first upper conductive pattern disposed on a top surface of the first substrate, and a first lower conductive pattern disposed on a bottom surface of the first substrate; the second coil unit includes a second substrate, a second upper conductive pattern disposed on a top surface of the second substrate, and a second lower conductive pattern disposed on a bottom surface of the second substrate; The coil portion a central portion in which each of the first upper conductive pattern, the first lower conductive pattern, the second upper conductive pattern, and the second lower conductive pattern forms a plurality of turns; a primary pattern lead-out portion disposed on one side of the central portion, where one end of each of the first upper conductive pattern and the first lower conductive pattern is led out from the central portion; a second pattern lead-out portion disposed on the other side of the central portion, where one end of each of the second upper conductive pattern and the second lower conductive pattern is led out from the central portion, In the second pattern extension portion, the second upper conductive pattern and the second lower conductive pattern overlap each other in a vertical direction so that at least a portion of the second upper conductive pattern intersects with the second lower conductive pattern on a plane.

2. The inductor of claim 1 , wherein the first upper conductive pattern, the first lower conductive pattern, the second upper conductive pattern, and the second lower conductive pattern each have a spiral planar shape.

3. the first upper conductive pattern has a spiral planar shape rotating in a first direction on a plane; The inductor of claim 2 , wherein one of the second upper conductive pattern and the second lower conductive pattern has a spiral planar shape that rotates in the first direction on a plane.

4. the first lower conductive pattern has a spiral planar shape rotating in a second direction opposite to the first direction on a plane; The inductor of claim 3 , wherein the other of the second upper conductive pattern and the second lower conductive pattern has a spiral planar shape that rotates in the second direction on a plane.

5. the other ends of the first upper conductive pattern and the first lower conductive pattern are electrically connected to each other through a first via hole that penetrates the first substrate; The inductor of any one of claims 1 to 4, wherein the other ends of the second upper conductive pattern and the second lower conductive pattern are electrically connected to each other through a second via hole that penetrates the second substrate.

6. The inductor according to claim 1 , wherein the first upper conductive pattern and the first lower conductive pattern are spaced apart from each other on a plane within the primary pattern lead-out portion.

7. The inductor of claim 1 , wherein a length of the second upper conductive pattern and a length of the second lower conductive pattern are the same within the second pattern lead-out portion.

8. 8. The inductor of claim 1, wherein a deviation between a sum of a first length of the first upper conductive pattern and the first lower conductive pattern and a sum of a second length of the second upper conductive pattern and the second lower conductive pattern is within 5%.

9. An inductor described in any one of claims 1 to 7, wherein the first sum of lengths of the first upper conductive pattern and the first lower conductive pattern is the same as the second sum of lengths of the second upper conductive pattern and the second lower conductive pattern.

10. An inductor as described in any one of claims 1 to 7, wherein the deviation between the third sum of lengths of the first upper conductive pattern and the first lower conductive pattern within the first pattern pull-out portion and the fourth sum of lengths of the second upper conductive pattern and the second lower conductive pattern within the second pattern pull-out portion is within 5%.

11. An inductor as described in any one of claims 1 to 7, wherein the third sum of lengths of the first upper conductive pattern and the first lower conductive pattern within the first pattern pull-out portion and the fourth sum of lengths of the second upper conductive pattern and the second lower conductive pattern within the second pattern pull-out portion are the same.

12. 12. The inductor of claim 8, wherein at least one of the first upper conductive pattern and the first lower conductive pattern in the primary pattern extension portion has a curved planar shape having a curvature at a point where the first upper conductive pattern and the first lower conductive pattern are closest to each other on a plane.

13. 12. The inductor of claim 8, wherein at least one of the first upper conductive pattern and the first lower conductive pattern in the primary pattern lead-out portion has an apex where the first upper conductive pattern and the first lower conductive pattern form an inflection at a point where they are closest to each other on a plane, and a bridge portion disposed around the apex.

14. An inductor described in any one of claims 1 to 13, wherein within the central portion, the lengths of the first upper conductive pattern, the first lower conductive pattern, the second upper conductive pattern and the second lower conductive pattern are the same.

15. One end of the first lower conductive pattern is a first input terminal, and one end of the first upper conductive pattern is a first output terminal; The inductor according to any one of claims 1 to 14, wherein one end of the second lower conductive pattern is a second input terminal and one end of the second upper conductive pattern is a second output terminal.

16. An inductor as described in Claim 15, wherein the direction in which a first current flows from the first input terminal to the first output terminal is the same as the direction in which a second current flows from the second input terminal to the second output terminal.

17. A substrate, a circuit portion formed on the substrate; an EMI filter electrically connected to the circuit unit, The EMI filter comprises: Including an inductor and a capacitor, The inductor is a core portion including an upper core and a lower core; a coil portion, the coil portion being partially disposed within the core portion and including a first coil portion and a second coil portion; The first coil portion a first substrate; a first upper conductive pattern disposed on a top surface of the first substrate; and a first lower conductive pattern disposed on a bottom surface of the first substrate; The second coil portion is a second substrate; a second upper conductive pattern disposed on a top surface of the second substrate; and a second lower conductive pattern disposed on a bottom surface of the second substrate; The coil portion a central portion in which each of the first upper conductive pattern, the first lower conductive pattern, the second upper conductive pattern, and the second lower conductive pattern forms a plurality of turns; a first pattern lead-out portion disposed on one side of the central portion, where one end of each of the first upper conductive pattern and the first lower conductive pattern is led out from the central portion; a second pattern lead-out portion disposed on the other side of the central portion, where one end of each of the second upper conductive pattern and the second lower conductive pattern is led out from the central portion, In the second pattern lead-out portion, the second upper conductive pattern and the second lower conductive pattern overlap each other in a vertical direction so that at least a portion of the second upper conductive pattern intersects on a plane.

18. A circuit board as described in Claim 17, wherein within the first pattern pull-out portion, the first upper conductive pattern and the first lower conductive pattern are spaced apart from each other in a plane.

19. A circuit board as described in claim 17 or 18, wherein the deviation between the first sum of lengths of the first upper conductive pattern and the first lower conductive pattern and the second sum of lengths of the second upper conductive pattern and the second lower conductive pattern is within 5%.

20. A circuit board as described in claim 17 or 18, wherein the deviation between the third sum of lengths of the first upper conductive pattern and the first lower conductive pattern within the first pattern pull-out portion and the fourth sum of lengths of the second upper conductive pattern and the second lower conductive pattern within the second pattern pull-out portion is within 5%.

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