Magnetic cores, inductors and EMI filters containing them

Abstract

To provide a magnetic core part excellent in magnetic properties and strength, and an inductor and an EMI filter that include the magnetic core part.SOLUTION: In an inductor, a magnetic core 800A comprises: a first magnetic body 810 having a toroidal shape, and including a ferrite; and a second magnetic body 820 disposed on an outer circumferential surface or an inner circumferential surface of the first magnetic body. The second magnetic body 820 includes: a second outer magnetic body 822 disposed on the outer circumferential surface S2 of the first magnetic body 810; and a second inner magnetic body 824 disposed on the inner circumferential surface S4 of the first magnetic body 810. The second outer magnetic body 822 and the second inner magnetic body 824 each have a thickness smaller than the thickness of the first magnetic body 810, and are obtained by forming a resin material on a metal ribbon wound in multiple layers.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a magnetic core, an inductor, and an EMI filter including the same. [Background technology]

[0002] An inductor is an electronic component that is applied to a printed circuit board and has electromagnetic properties. This can be applied to a resonant circuit, a filter circuit, a power circuit, etc.

[0003] On the other hand, EMI (Electro Magnetic Insulation) applied inside the power board An interference filter passes signals necessary for circuit operation and removes noise. It plays a role in

[0004] Figure 1 shows a typical power board with an EMI filter connected to a power supply and a load. FIG. 1 is a block diagram showing the configuration of the system.

[0005] The types of noise transmitted from the power board of the EMI filter shown in Figure 1 are broadly The radiated noise from the power board in the frequency range of 30MHz to 1GHz and the noise transmitted through the power line It can be divided into conducted noise in the range of 150 kHz to 30 MHz and conducted noise in the range of 150 kHz to 30 MHz.

[0006] The transmission method of conducted noise is the same as differential mode. Common mode noise is a small Even if the amount is small, it returns in a large loop, so it can reach electronic devices far away. Such common mode noise can also affect the impedance imbalance of the wiring system. This can also occur due to noise, and becomes more pronounced in high frequency environments.

[0007] To eliminate common mode noise, the inductor applied to the EMI filter shown in Figure 1 The rotor is generally a toroidal rotor containing Mn-Zn ferrite material. Mn-Zn ferrite core is used for 100kHz to 1 Its high permeability at MHz allows it to effectively filter out common mode noise.

[0008] FIG. 2 is a perspective view showing a general inductor 100. As shown in FIG.

[0009] Referring to FIG. 2, the inductor 100 includes a magnetic core 110 and a A wound coil 120 may be included.

[0010] The magnetic core 110 may be toroidal in shape, and the coil 120 may be a magnetic A first coil 122 is wound on the magnetic core 110, and a second coil 123 is wound opposite to the first coil 122. The first coil 122 and the second coil 124 may include a second coil 124. The windings can be wound on the top surface S1, the side surface S2, and the bottom surface S3 of the toroidal magnetic core 110, respectively. do.

[0011] The magnetic core 110 may further include a bobbin (not shown) for insulating the coil 120. The coil 120 may be made of a conductive wire whose surface is coated with an insulating material.

[0012] FIG. 3 is an exploded perspective view of the magnetic core shown in FIG. 2 further including a bobbin, and FIG. 4 is a perspective view of a process for manufacturing the magnetic core shown in FIG. 3.

[0013] 3, the magnetic core 110 may be housed in a bobbin 130. The bobbin 130 may include: An upper bobbin 132 and a lower bobbin 134 may be included.

[0014] Next, referring to FIG. 4(a), the upper bobbin 132, the magnetic core 110, and the With the lower bobbin 132 provided, the magnetic core 110 is disposed on the bottom surface of the lower bobbin 132. Then, as shown in FIG. 4(b), the upper bobbin is applied to the result shown in FIG. 4(a). In this case, each component may be bonded to each other with an adhesive.

[0015] In order to improve the performance of the inductor, the magnetic core 110 may be made of a different material. As an example, the Mn-Zn ferrite (F The surface of a toroidal magnetic core containing errite material is However, the metal ribbons have high magnetic properties. To obtain the desired properties (i.e., high magnetic permeability), heat treatment is performed at high temperatures (e.g., 500°C to 600°C). However, metal ribbons that have undergone high-temperature heat treatment tend to retain their magnetic properties. Although the strength is improved, the strength is too weak and it is prone to brittleness even with a small impact. ) and it becomes very difficult to transport and handle during the manufacturing process, resulting in a decrease in workability. This also leads to a problem of a decrease in the yield of the finished product. Summary of the Invention [Problem to be solved by the invention]

[0016] The technical problem that the present invention aims to achieve is to provide a magnetic core component having excellent magnetic properties and strength, and The present invention provides an inductor and an EMI filter including: [Means for solving the problem]

[0017] The inductor according to one embodiment has a toroidal shape and includes a first magnetic material including ferrite. and a second magnetic body disposed on an outer circumferential surface or an inner circumferential surface of the first magnetic body, The first magnetic body includes a plurality of layers of metal ribbons and a resin material wound around the circumference of the first magnetic body. The resin material is a first resin material arranged to cover the outer surface of the multiple layers of metal ribbons, and a multiple layers of and a second resin material disposed in at least a portion of the interlayer space.

[0018] For example, the first magnetic body includes a Mn-Zn ferrite, and the second magnetic body includes a Fe-Si metal. The second resin material includes a ribbon, and the second resin material extends from the lower surface to the upper surface of the second magnetic body relative to the entire height of the second magnetic body. It can be placed in the range of 0% to 5% and in the range of 95% to 100%.

[0019] For example, the thickness of the first magnetic body in the diametric direction is greater than the thickness of the second magnetic body in the diametric direction, and The magnetic body may have a diametrical thickness greater than the diametrical thickness of the first resin material.

[0020] For example, the thickness of the first resin material may be 20 μm to 30 μm.

[0021] For example, the height of the first resin material layer may be greater than the height of the second magnetic body.

[0022] For example, the second resin material may be disposed in an amount of 15% to 30% of the interlayer spaces between the multiple layers.

[0023] For example, the second resin material may be disposed in an amount of 20% to 25% of the interlayer spaces between the multiple layers.

[0024] The EMI filter according to the embodiment includes an inductor and a capacitor. The magnetic core has a toroidal shape and includes a first magnetic body containing ferrite, and the first magnetic body has an outer circumferential surface or an inner circumferential surface thereof. a second magnetic body disposed on the circumferential surface of the first magnetic body, the second magnetic body being arranged along the circumferential direction of the first magnetic body; The metal ribbon may include multiple layers of wound metal ribbon and a resin material, where the resin material is a first resin substance disposed so as to cover the outer surfaces of the plurality of layers of metal ribbons; and and a second resin material disposed at least partially therebetween.

[0025] For example, the first magnetic body includes a Mn-Zn ferrite, and the second magnetic body includes a Fe-Si metal. The second resin material includes a ribbon, and the second resin material extends from the lower surface to the upper surface of the second magnetic body relative to the entire height of the second magnetic body. It can be placed in the range of 0% to 5% and in the range of 95% to 100%.

[0026] For example, a portion of the second resin material may be disposed in an amount of 15% to 30% relative to the interlayer space of the plurality of layers. do. [Effects of the Invention]

[0027] The inductor and the EMI filter including the inductor according to the embodiment are formed by winding a plurality of layers. The metal ribbon magnetic core is coated with a resin material, improving strength while providing excellent It has excellent magnetic properties. [Brief explanation of the drawings]

[0028] [Figure 1] This is a block diagram showing a general power board to which an EMI filter is applied, connected to a power supply and a load. [Figure 2] FIG. 1 is a perspective view showing a general inductor. [Figure 3] 3 is an exploded perspective view showing a case where the magnetic core shown in FIG. 2 further includes a bobbin. [Figure 4] 4 is a perspective view of the magnetic core shown in FIG. 3 in a manufacturing process. [Figure 5] 1A and 1B are a perspective view and a cross-sectional view of a magnetic core according to an embodiment of the present invention; [Figure 6] FIG. 6 is a process diagram of the magnetic core of FIG. 5. [Figure 7] 10A and 10B are a perspective view and a cross-sectional view of a magnetic core according to still another embodiment of the present invention; [Figure 8] 10A and 10B are a perspective view and a cross-sectional view of a magnetic core according to still another embodiment of the present invention; [Figure 9] 10A and 10B are a perspective view and a cross-sectional view of a magnetic core according to still another embodiment of the present invention; [Figure 10] 1 is a graph showing the magnetic permeability and inductance of a ferrite material and a metal ribbon material. [Figure 11] 1 is a cross-sectional image showing the epoxy ratio in the interlayer space depending on the dilution ratio of the epoxy coating liquid according to an embodiment. [Figure 12] FIG. 12 is a diagram for explaining a sample measurement region according to the embodiment. [Figure 13] FIG. 13 shows the measurement results for each region in FIG. [Figure 14] 1 is an example of an EMI filter including an inductor according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention can be modified in various ways and can have various embodiments. Specific embodiments will be illustrated and described in the drawings. However, this does not mean that the invention is limited to specific implementations. It is not intended to be limited to the form, and all forms within the spirit and technical scope of the present invention are included. It should be understood that this includes any modifications, equivalents or alternatives.

[0030] Ordinal terms such as second, first, etc. may be used to describe various components. However, these terms do not limit the components. Terms are used only to distinguish one component from another. Without departing from the scope of the invention, the second element may be named as the first element, and similarly The term and / or may be used to refer to multiple relationships. It includes any combination of related items or a plurality of related items.

[0031] When an element is referred to as being "coupled" or "connected" to another element, When a component is connected to another component, it may be directly connected or directly connected to the other component. It should be understood that there may be additional components between the two. When an element is said to be "directly coupled" or "directly connected" to another element, In such cases, it should be understood that there are no further components in between.

[0032] In the description of the embodiments, each layer (film), region, pattern or structure is a substrate, each layer (film), region Shaped "on" or "under" an area, pad, or pattern The phrase "formed" means formed directly or via other layers. The reference to the top / top or bottom / bottom of each layer is explained based on the drawing. In addition, the thickness and size of each layer (film), region, pattern or structure in the drawings may be omitted from the description. The dimensions may be modified for clarity and convenience, and may not reflect the actual size. do not have.

[0033] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the scope of the present invention. The singular term "a," "the," or "the" is used unless the context clearly dictates otherwise. In this application, terms such as "including" or "having" are used to refer to the Any feature, number, step, operation, component, part or combination thereof described in It is intended to specify the presence of one or more other features, numbers, steps, actions, The possibility of the presence or addition of any work, component, part or combination thereof is not excluded in advance. It should be understood that this does not exclude

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, , which are generally understood by those skilled in the art to which the present invention pertains. Terms as defined in commonly used dictionaries have the same meaning as those in the related art. shall be interpreted to have a meaning consistent with the meaning in the context of the Unless expressly defined, it is not to be construed in an idealized or overly formal sense.

[0035] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Corresponding components are given the same reference numerals, and duplicated descriptions thereof will be omitted. do.

[0036] According to one embodiment of the present invention, the magnetic core includes a first magnetic body and a second magnetic body made of different materials. The magnetic material may include a second magnetic material, where the second magnetic material covers at least a portion of the surface of the first magnetic material. The metal ribbon may be disposed on a surface and may include multiple layers of wound metal ribbon. This second magnetic body solves the problem of weakening strength after heat treatment of wound multi-layer metal ribbons. The resin material may include a resin material for forming a multi-layered metal ribbon wound thereon. a resin material covering the outer surface of the plurality of layers, and a resin material disposed in at least a portion of the interlayer spaces of the plurality of layers. Here, the interlayer space is defined as the space between the layers that is created by the centrifugation caused by the winding of the metal ribbon. In two ribbon layers adjacent to each other in the direction, the outer surface of the layer relatively closer to the centrifugal The term "a space" can refer to a space formed between the inner surface of the layer farthest from the centrifuge and the surface of the resin material. The details of the characteristics will be described later. First, referring to FIGS. 5 to 8, the different characteristics according to the embodiment of the present invention will be described. Various forms of magnetic materials constituting the magnetic core will be described. For convenience of explanation, FIGS. 7, the resin material is not shown.

[0037] FIG. 5 is a perspective view and a cross-sectional view of a magnetic core according to an embodiment of the present invention, and FIG. 6 is a perspective view and a cross-sectional view of the magnetic core shown in FIG. 7 to 9 are perspective views and a diagram of a magnetic core according to another embodiment of the present invention. FIG.

[0038] Referring to FIG. 5, the magnetic core 800 includes a first magnetic body 810 and a second magnetic body 820. The first magnetic body 810 and the second magnetic body 820 are different types, and the second magnetic body 820 is the first magnetic body. The second magnetic body 820 may be disposed on at least a portion of the surface of the first magnetic body 810. It may have a higher saturation magnetic flux density than body 810.

[0039] Here, the first magnetic body 810 includes ferrite, and the second magnetic body 820 includes a metal ribbon. Here, the magnetic permeability (μ) of ferrite can be 2,000 to 15,000. The magnetic permeability (μ) of the metal ribbon can be 100,000 to 150,000. The ferrite can be a Mn-Zn based ferrite and the metal ribbon can be an Fe based nanocrystalline metal ribbon. The Fe-based nanocrystalline metal ribbon may be a nanocrystalline metal ribbon containing Fe and Si. The thickness of the metal ribbon can be 15 μm to 20 μm, but is not necessarily limited to this. It will not be done.

[0040] At this time, the first magnetic body 810 and the second magnetic body 820 are each toroidal. The second magnetic body 820 includes a second outer magnetic body 822 disposed on the outer peripheral surface S2 of the first magnetic body 810, and a second inner magnetic body 824 disposed on the inner circumferential surface S4 of the first magnetic body 810. do.

[0041] At this time, the thickness of the second outer magnetic body 822 and the second inner magnetic body 824 is equal to that of the first magnetic body. The thickness of the second outer magnetic body 822 is thinner than the thickness of the first magnetic body 810. and at least one of the ratio between the thickness of the second inner magnetic body 824 and the thickness of the first magnetic body 810. By adjusting either of these, the magnetic permeability of the magnetic core 800 can be adjusted.

[0042] To manufacture such a magnetic core, two second magnetic bodies 822, Each of the second magnetic bodies 822 and 824 is a metal wire wound in multiple layers. The second magnetic bodies 822 and 824 may be formed of a resin material. The second inner magnetic body 824 corresponding to the inner circumferential surface S4 of the toroidal first magnetic body 810 is The first magnetic body 810 is inserted into the hollow of the first magnetic body 810, and the first magnetic body 810 also has a second outer magnetic body corresponding to the outer peripheral surface S2. Of course, the relative position of each second magnetic body to the first magnetic body 810 can be adjusted. The join order may be changed.

[0043] At this time, the outer peripheral surface S2 of the first magnetic body 810, the second outer magnetic body 822, and the first magnetic body 8 The inner circumferential surface S4 of the magnetic body 10 and the second inner magnetic body 824 may be bonded with an adhesive. The adhesive may be at least one of epoxy resin, acrylic resin, silicon resin, and varnish. In this way, when different types of magnetic materials are joined using an adhesive, , and performance degradation will no longer occur even when physical vibrations occur.

[0044] Here, each of the second magnetic bodies 822 and 824 is wound multiple times as shown in FIG. The metal ribbon may be laminated in multiple layers. The thickness and magnetic permeability of the second magnetic bodies 822 and 824 change depending on the number of layers. The magnetic permeability of Core 800 changes, and the noise reduction of the EMI filter to which Magnetic Core 800 is applied Removal performance may vary.

[0045] That is, the thicker the second magnetic bodies 822 and 824 are, the higher the noise removal performance can be. Using this principle, the second magnetic body 822, which is arranged in the area where the coil is wound, The thickness of 824 is the thickness of the second magnetic bodies 822 and 824 arranged in the area where the coil is not wound. The number of layers of metal ribbons stacked can be adjusted so that the thickness is greater than the thickness.

[0046] The number of layers of the metal ribbon depends on the number of windings, the winding start point and the winding As shown in FIG. 5(a), the outer circumferential surface of the first magnetic body 810 The relationship between the start point and the end point of the winding is determined based on the second outer magnetic body 822 arranged at S2. The relationship between the first magnetic body 810 and the second outer magnetic body 822 is as follows. Before joining, the winding and resin material (not shown) are already formed. As mentioned above, for the sake of convenience, the magnetic flux is generated at one point on the outer circumferential surface of the first magnetic body 810. It is assumed that winding starts based on

[0047] When winding the second outer magnetic body 822, which is a metal ribbon, When winding once from the starting point, the second outer magnetic body 822 includes one layer of metal ribbon. If you wind twice from the winding start point, the second outer magnetic The body 822 can include two layers of metal ribbon. If the winding end points are different from each other, for example, 1.5 turns from the winding start point When binding, the second outer magnetic body 822 is a region where a metal ribbon is laminated in one layer. This includes the area where the metal ribbon is stacked in two layers. When winding 2.5 times from the point, the second outer magnetic body 822 has two layers of metal ribbon. This includes the area where the metal ribbon is laminated in three layers and the area where the metal ribbon is laminated in three layers. If the coil is arranged in an area with a larger number of layers, the magnetic core 800 according to the embodiment of the present invention can be This can further improve the noise removal performance of the EMI filter to which it is applied.

[0048] For example, the magnetic core 800 is toroidal, and the first coil 122 is disposed on the magnetic core 800. When the first and second coils 124 are wound symmetrically, the first and second coils 124 are arranged on the outer circumferential surface of the first magnetic body 810. The first coil 122 is disposed in a region where the number of stacked layers of the second outer magnetic body 822 is large. The area where the number of layers of the second inner magnetic body 824 arranged on the inner circumferential surface of the first magnetic body 810 is large is The second coil 124 can be placed in the region. The two coils 124 are formed in the region where the number of layers stacked in the second magnetic bodies 822 and 824 is large. In the region where the number of layers is small, the first coil 122 and the second coil 124 are arranged. is not arranged, high noise removal performance can be obtained.

[0049] Assuming that the second outer magnetic body 822 and the second inner magnetic body 824 have the same material and thickness, However, the present invention is not limited to this. 4 may have different materials or different magnetic permeabilities, and may have different thicknesses. This allows the magnetic core 800 to have a range of magnetic permeability.

[0050] On the other hand, as shown in FIG. 7, the height h1 of the first magnetic body 810 is greater than the height h2 of the second magnetic body 820. For this reason, in the manufacturing process of the second magnetic body 820, the high A metal ribbon having a width shorter than the thickness h1 can be wound up. 2 is the boundary between the upper surface S1 and the outer peripheral surface S2 of the first magnetic body 810 and the lower surface S3 of the first magnetic body 810 and the outer peripheral surface S2, and the second inner magnetic body 824 is not disposed at the boundary between the upper surface of the first magnetic body 810 and the outer peripheral surface S3. and the boundary between the lower surface S3 of the first magnetic body 810 and the inner peripheral surface S4. This prevents the boundary between the upper surface S1 and the outer peripheral surface S2 of the first magnetic body 810 from being broken. The boundary between the bottom surface S3 and the outer peripheral surface S2 of the first magnetic body 810, the top surface S1 and the inner peripheral surface S2 of the first magnetic body 810, The second outer magnetic body 810 is formed at the boundary between the first magnetic body 810 and the inner peripheral surface S4 of the first magnetic body 810, and at the boundary between the lower surface S3 of the first magnetic body 810 and the inner peripheral surface S4 of the second outer magnetic body 810. This can prevent cracks in the insulating body 822.

[0051] Alternatively, as shown in FIG. 8, the second magnetic body 820 is formed only on the outer peripheral surface S2 of the first magnetic body 810. As shown in FIG. 9, the second magnetic body 820 may be disposed on the inner circumferential surface S of the first magnetic body 810. It may only be placed on 4.

[0052] In this way, if the magnetic core 800 contains different types of magnetic materials with different magnetic permeabilities, a wide range of frequencies can be achieved. It is possible to remove noise in the band. In particular, toroidal Compared to a magnetic core with a shaped core, the phenomenon of magnetic flux gathering on the surface is prevented, so high frequency noise can be removed. The effect is large and the internal saturation is low, so it can be applied to high-power products. By adjusting the magnetic permeability and volume ratio of the magnetic body 810 and the second magnetic body 820, the magnetic core 800 The performance can be adjusted.

[0053] On the other hand, referring to Figure 10, the magnetic permeability of ferrite material and metal ribbon material differs depending on frequency. A magnetic core that includes all of these elements exhibits high inductance in a specific frequency range, resulting in high It can be seen that excellent noise reduction performance can be obtained.

[0054] The above has described the relative positional relationship between the first magnetic body and the second magnetic body according to the embodiment. Next, the resin material of the second magnetic body according to an embodiment of the present invention will be described in more detail.

[0055] According to one embodiment, the resin material is applied by heat treating a metal ribbon wound into a plurality of layers. It can be formed by dipping the processed product in a coating liquid and then drying it. In some embodiments, the drying process may include a thermal drying process in an environment of 60° to 150°. do.

[0056] As shown in FIG. 8(c), in the second magnetic body 820, the resin material R is wound around the metal. The metal ribbon MR is placed on the outer surface (upper surface, lower surface, inner peripheral surface, outer peripheral surface) and wound up. It may also be placed between the bones (not shown).

[0057] According to one embodiment, the coating liquid is a mixture of epoxy resin and diluent in a predetermined ratio. The diluent may be a mixture of specific components as long as it can dissolve the epoxy resin. The following Tables 1 to 4 show the results of inductor tests using different ratios of epoxy resin and diluent. An example of the results of measuring the rate of decrease in performance is shown below.

[0058] [Table 1]

[0059] [Table 2]

[0060] [Table 3]

[0061] [Table 4]

[0062] Referring to Tables 1 to 4, the higher the ratio of epoxy resin, the higher the inductance reduction rate. It can be seen that the higher the diluent ratio, the smaller the inductance reduction rate. When the ratio of epoxy resin to diluent is 5:5, the inductance reduction rate is close to 30%. When the ratio of epoxiesin to diluent was 3:7, the inductance reduction rate was approximately 15%. However, the inductance when the ratio of epoxy resin to diluent is 2:8 and 1:9 The decrease rates are 5.72% and 4.7%, respectively, and the difference is not large, but it is a relatively good indicator. The inductance reduction rate was shown.

[0063] Next, the strength of each diluent is compared with reference to Table 5.

[0064] [Table 5]

[0065] Table 5 shows the results of the heat treatment of a metal ribbon wound into 15 turns at one point on the outer surface. The external force required to cause damage when applying pressure in the diametric direction is shown in g. See Table 5. When an external force of about 70 g is applied to the metal ribbon before it is soaked in the coating liquid, However, depending on the ratio of epoxy resin to diluent, the strength can be increased by approximately 3 to 10 times. It can be seen that...

[0066] The difference in strength improvement depending on the dilution ratio is due to the dilution of the coating liquid (i.e., the impregnation liquid). The viscosity of the epoxy resin varies depending on the dilution ratio, so when picking up the metal ribbon after impregnation, This is one of the reasons why a relatively large amount of epoxy remains on the outer periphery of the ribbon, but it is also because the gold wound in the impregnation liquid This is also due to the increased amount of epoxy resin that penetrates into the interlayer spaces of the metal ribbon. In addition, the volume of epoxy resin in the spaces between the layers of the wound metal ribbon increases during the drying process. As the wire expands, microcracks increase in the metal ribbon, causing a decrease in inductance. This will be explained with reference to Figs. 11 to 13. Although not shown in the figures, Figs. In 13, the position where the resin material is arranged in the interlayer space of the wound ribbon is 2. When the total height of the magnetic body 820 is defined as the height from the bottom surface to the top surface, They can be arranged in the region of 0% to 5% and the region of 95% to 100% of the total height. Located in the areas of 0% to 15% and 85% to 100% of the total height from the bottom to the top More preferably, the thickness of the slit is 0% to 30% and 70% to 100% of the total height in the direction from the bottom to the top. 00% of the total height from the bottom to the top. , the strength improvement and inductance reduction may be slight.

[0067] FIG. 11 shows the epoxy content in the interlayer space depending on the dilution ratio of the epoxy coating liquid according to the embodiment. Figure 11 shows a cross-sectional image of a metal ribbon wound into 15 layers (turns). The second magnetic material is impregnated with epoxy coating liquid with different dilution ratios. The images in Figure 11 are enlarged cross-sections after cutting. The end is the centrifugal direction, and the top image shows all 15 layers of metal ribbon for each dilution ratio. The bottom image is further enlarged to show only the five layers of metal ribbon. The circles in the bottom images indicate the areas where the epoxy resin is located. do.

[0068] Referring to Figure 11, when the epoxy to diluent ratio is 1:9, the adjacent ribs in the centrifugal direction The epoxy resin is located in the space between the bond layers, i.e., in a ratio of about 10% of the entire interlayer space. If the ratio of epoxy to diluent is 2:8, the epoxy resin will be present at about 25%. Also, when the ratio of epoxy to diluent is 3:7, the ratio of the entire interlayer space is about 30%. When the epoxy resin is located in the epoxy and diluent ratio is 5:5, the epoxy resin is about 50%. The epoxy resin is located.

[0069] As shown in Figure 11, the strength changes depending on the ratio of epoxy resin in the interlayer space. We can see that.

[0070] Below, we will comprehensively compare the inductance reductions in Tables 1 to 4 and the strength improvements in Table 5. .

[0071] A 5:5 ratio of epoxy to diluent provides the highest strength but reduces inductance. If the ratio is too high and the epoxy to diluent ratio is 1:9, the inductance reduction rate is the lowest. The strength improvement was also low.

[0072] In addition, when the ratio of epoxy to diluent is 2:8 and 1:9, respectively, the inductance The epoxy and diluent ratios were similar in terms of strength improvement. Similar superiority was observed at ratios of 2:8 and 3:7, respectively.

[0073] In other words, if the ratio of epoxy to diluent is 2:8, the inductance reduction is 1: It shows a similar degree of excellence to the case of 9, and the strength is similar to the case of 3:7. As shown, this is the most preferable ratio.

[0074] Therefore, in the following, when the ratio of epoxy to diluent is 2:8, the epoxy in the interlayer space The ratio will be explained more specifically with reference to FIGS.

[0075] FIG. 12 is a diagram for explaining a sample measurement area according to the embodiment, and FIG. 13 is a diagram for explaining a sample measurement area according to the embodiment. These are the measurement results for each of the two areas.

[0076] FIG. 12 shows the results of the coating liquid immersed in the coating solution having a dilution ratio of 2:8 according to the embodiment and then dried. A plan view of the dried second magnetic body 820 is shown. The second magnetic body 820 is divided into four areas, Area_1 to Area_4, Therefore, a cross-sectional image of one second magnetic sample is taken. The epoxy ratio in the interlayer space was measured four times for each sample, for a total of 20 measurements using five samples. A decision was made.

[0077] Figure 13 shows images of some samples taken during this measurement process. The metal ribbon wound into 15 turns was then coated with an epoxy resin with a dilution ratio of 2:8. The second magnetic body impregnated with the coating liquid was cut in the circumferential direction, and then the cross section was enlarged. In addition, in Figure 13, the bottom of each image is in the centrifugal direction, and the top The images in the bottom row indicate which part of the cross section the image in the bottom row corresponds to, and the bottom row shows the five layers. The images are further enlarged so that only the metal ribbons are visible. means the area where the epoxy resin is located.

[0078] In Figure 13(a), the epoxy resin occupies 15% of the interlayer space, and in Figure 13(b), The ratio is 20% in (c) of Figure 13, 25% in (d) of Figure 13, and 30% in (d) of Figure 13. This indicates that epoxy occupies the

[0079] In other words, when the dilution ratio is 2:8, the epoxy ratio in the interlayer space is 15% to 30%. This is a range including the maximum and minimum values, and the results of 20 measurements are shown in Table 6 below.

[0080] [Table 6]

[0081] Referring to Table 6, in a total of 20 experiments, there were two 15% cases and four 20% cases. The dilution ratio was 100% in 10 cases, 25% in 7 cases, and 30% in 3 cases. If the ratio is 2:8, the epoxy ratio in the interlayer space is 15% to 30%, preferably 20% to 25%. %, more preferably 23% to 25%. The thickness of the outer coating layer can be 10 μm to 40 μm, preferably 20 μm to 30 μm. If the thickness is less than 10 μm, the strength is low and the metal ribbon breaks. If it is larger than 40μm, the inductance reduction rate will be large and performance will be deteriorated. may decrease.

[0082] Meanwhile, the inductor according to the above-described embodiment can be included in a line filter. The line filter is suitable for AC-to-DC converters. FIG. 14 shows an inductor according to an embodiment of the present invention. This is an example of an EMI filter that includes

[0083] Referring to FIG. 14, the EMI filter 2000 includes a plurality of X-capacitors Cx, a plurality of The circuit may include a Y-capacitor Cy and an inductor L.

[0084] The X-capacitor Cx is connected between the first terminal P1 of the live line LIVE and the neutral line N Between EUTRAL's third terminal P3 and LIVE's second terminal P2 and New and the fourth terminal P4 of the NEUTRAL line.

[0085] The Y-capacitors Cy are connected to the second terminal P2 of the live line LIVE and the neutral line The fourth terminal P4 of the input NEUTRAL may be disposed in series with the fourth terminal P4 of the input NEUTRAL.

[0086] The inductor L is connected between the first terminal P1 and the second terminal P2 of the live line LIVE, It may be disposed between the third terminal P3 and the fourth terminal P4 of the neutral line NEUTRAL. Here, the inductor L can be the inductor 100 according to the above embodiment.

[0087] When common mode noise enters the EMI filter 2000, the primary inductance (P Composite impedance characteristics of Y-capacitor Cy and Y-primary inductance Here, the primary inductor of the live line LIVE is The third and fourth terminals P3 and P4 are open, and the first and second The inductance between terminals P1 and P2 can be measured and the neutral line NE The primary inductance of the UTRAL is set by opening the first and second terminals P1 and P2. n) and measure the inductance between the third and fourth terminals P3 and P4. can.

[0088] When differential mode noise enters the EMI filter 2000, the leakage inductance (l Composite impedance characteristics of the X-capacitor Cx and the leakage inductance Here, the leakage inductance of the live line LIVE is The first and second terminals are connected while the third and fourth terminals P3 and P4 are shorted. The inductance between P1 and P2 can be measured and the neutral line NEUT The leakage inductance of the RAL is the third and fourth terminals when the first and second terminals P1 and P2 are short-circuited. The inductance between the first terminal P1 and the fourth terminal P2 can be measured.

[0089] The inductor of the EMI filter 2000 according to the embodiment is the inductor according to the embodiment described above. This applies to the ctor.

[0090] The description of each of the above embodiments may be used interchangeably with other embodiments unless the contents are inconsistent. It is also applicable to

[0091] The above description has been centered on the examples, but these are merely examples and do not limit the present invention. In addition, a person having ordinary skill in the art to which the present invention pertains will be able to easily understand the essential features of this embodiment. It is understood that various modifications and applications not exemplified above are possible within the scope of the invention. For example, each component specifically shown in the embodiment can be modified and implemented. and the differences relating to such modifications and applications are defined in the appended claims. should be construed as being included within the scope of the present invention.

Claims

1. a toroidal first magnetic body including a first inner peripheral surface disposed at the innermost side along the centrifugal direction and a first outer peripheral surface disposed at the outermost side along the centrifugal direction; a second magnetic body disposed on at least one of the first inner circumferential surface and the first outer circumferential surface of the first magnetic body, The second magnetic body is a metal ribbon provided in a plurality of layers along the centrifugal direction, the metal ribbon including a second inner circumferential surface disposed on the innermost side along the centrifugal direction, a second outer circumferential surface disposed on the outermost side along the centrifugal direction, an upper surface of each of the plurality of layers disposed between the second inner circumferential surface and the second outer circumferential surface, and a lower surface of each of the plurality of layers disposed between the second inner circumferential surface and the second outer circumferential surface; a resin portion covering the upper surface, the lower surface, the second inner peripheral surface, and the second outer peripheral surface of the metal ribbon; a first resin member and a second resin member disposed spaced apart from each other between the plurality of layers of the metal ribbon, The first resin member and the second resin member are spaced apart from the resin portion.

2. 2. The magnetic coupling device according to claim 1, wherein the first resin member has a length in the vertical direction that is different from the length of the second resin member in the vertical direction.

3. further comprising a third resin member disposed between the plurality of layers of the metal ribbon; The magnetic coupling device according to claim 1 , wherein at least a portion of the third resin member is in contact with the resin portion.

4. 4. The magnetic coupling device according to claim 3, wherein the vertical length of the third resin member is greater than 0% and less than or equal to 5% of the vertical length of the metal ribbon.

5. The magnetic coupling device according to claim 3 , wherein the third resin member has a vertical length equal to the vertical length of the metal ribbon and is in contact with the resin portion.

6. 4. The magnetic coupling device according to claim 3, wherein at least one of the first resin member, the second resin member, and the third resin member occupies 15% to 30% of the space between the plurality of layers.

7. the first magnetic body includes a Mn—Zn-based material, The magnetic coupling device of claim 1 , wherein the metal ribbon comprises an Fe—Si based material.

8. The metal ribbon extends 15 times along the circumferential direction of the first magnetic body, The magnetic coupling device of claim 1 , wherein the plurality of layers of metal ribbons are provided in a number of 15 layers along the centrifugal direction.

9. 2. The magnetic coupling device according to claim 1, further comprising a coil wound around the first magnetic body and the second magnetic body in a perpendicular direction.

10. The magnetic coupling device of claim 9 , wherein the magnetic coupling device is an EMI filter or an inductor.

11. The magnetic coupling device according to claim 9 , wherein the coil is provided in a plurality of layers along the circumferential direction of the first magnetic body.

12. 2. The magnetic coupling device according to claim 1, wherein the vertical length of the second magnetic body is different from the vertical length of the first magnetic body.

13. The magnetic coupling device according to claim 12 , wherein the length of the first magnetic body in the vertical direction is greater than the length of the second magnetic body in the vertical direction.

14. 2. The magnetic coupling device according to claim 1, wherein the vertical length of the second magnetic body is the same as the vertical length of the first magnetic body.

15. 2. The magnetic coupling device according to claim 1, wherein the length of the first magnetic body in the centrifugal direction is greater than the length of the second magnetic body in the centrifugal direction.

16. 2. The magnetic coupling device according to claim 1, wherein the thickness of the resin portion in the centrifugal direction is 10 μm to 40 μm.

17. 17. The magnetic coupling device according to claim 16, wherein the thickness of the resin portion in the centrifugal direction is the thickness of a portion of the metal ribbon disposed on the second outer circumferential surface or the second inner circumferential surface.

18. A method for manufacturing a magnetic coupling device according to claim 1, preparing a toroidal first magnetic body including a first inner circumferential surface disposed at an innermost position along a centrifugal direction and a first outer circumferential surface disposed at an outermost position along the centrifugal direction; winding a metal ribbon in a circumferential direction to have a plurality of layers in the centrifugal direction; impregnating the metal ribbon with resin to form a first resin member and a second resin member spaced apart along the centrifugal direction between the plurality of layers of the metal ribbon, and a resin portion covering the metal ribbon; drying the first resin member, the second resin member, and the resin portion; and placing the resin portion covering the metal ribbon on the first inner circumferential surface or the first outer circumferential surface of the first magnetic body.

19. The method for manufacturing a magnetic coupling device according to claim 18, wherein the step of drying the first resin member, the second resin member, and the resin portion includes a step of thermally drying them in an environment of 60°C or higher and 150°C or lower.

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