Coil electronic component

Abstract

To provide a coil electronic component having a high breakdown voltage (BDV), and a high flatness of an electrode, and securing a sufficient MUF gap.SOLUTION: A coil electronic component has: a body having a first face and a second face facing each other in a first direction, a third face and a fourth face facing each other in a second direction and connecting the first face and the second face, and a fifth face and a sixth face facing each other in a third direction and connecting the first face and the second face, the body containing a magnetic material; a coil at least partially embedded in the body; an insulation layer arranged over the sixth face of the body; a conductive layer covering a portion of the insulation layer; and an external electrode covering the conductive layer and being connected to the coil. When the coil electronic component has a first length L1 in the first direction and has a second length L2 in the first direction of an area where the insulation layer, the conductive layer, and the external electrode overlap each other, the ratio of the second length L2 to the first length L1 (L2 / L1) ranges from 0.3 to 0.7.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to coil electronics, and more particularly to coil electronics with improved breakdown voltage (BDV). [Background technology]

[0002] In recent years, as the functions of mobile devices become more diverse and power consumption increases, coil electronic components with low loss and excellent efficiency are being adopted around power semiconductors (power management integrated circuits: PMICs) to extend the battery life of mobile devices. 2. Description of the Related Art There is an increasing demand for thin power inductors in order to slim down products and increase the freedom of component layout.

[0003] In this case, however, an increase in leakage current and a decrease in breakdown voltage (BDV) may occur. If the surface of the external electrodes is not flat or if there is not enough MUF (molded underfill) gap, it may be difficult to ensure mounting stability. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in consideration of the problems with the conventional coil electronic components described above, and an object of the present invention is to provide a coil electronic component with an improved breakdown voltage (BDV). Another object of the present invention is to provide a coil electronic component that improves the flatness of the electrodes and ensures a sufficient MUF gap. [Means for solving the problem]

[0005] The coil electronic component according to the present invention, made to achieve the above-mentioned object, is a coil electronic component having a first surface and a second surface facing a first direction, a third surface and a fourth surface facing a second direction and connecting the first surface and the second surface, and a fifth surface and a sixth surface facing a third direction and connecting the first surface and the second surface, the coil electronic component having a main body containing a magnetic material, a coil at least a portion of which is embedded in the main body, an insulating layer disposed on the sixth surface of the main body, a conductive layer covering a portion of the insulating layer, and an external electrode covering the conductive layer and connected to the coil, the coil electronic component having a first length L1 in the first direction, and a ratio (L2 / L1) of a second length L2 in the first direction of a region where the insulating layer, the conductive layer, and the external electrode overlap to the first length L1 is greater than or equal to 0.3 and less than 0.7.

[0006] The insulating layer is preferably spaced apart from the first surface and the second surface of the body, respectively. It is preferable that the conductive layer includes a first conductive layer covering the sixth surface between the insulating layer and the first surface of the body, and a second conductive layer covering the sixth surface between the insulating layer and the second surface of the body. It is preferable that the first conductive layer and the second conductive layer are spaced apart from each other, the first conductive layer covers the first surface of the insulating layer, and the second conductive layer covers the second surface of the insulating layer. The external electrodes preferably include a first external electrode covering the first conductive layer, and a second external electrode covering the second conductive layer. It is preferable that the first external electrode extends to the first surface of the body and is connected to the coil, and the second external electrode extends to the second surface of the body and is connected to the coil. It is preferable that the second length L2 is the sum of a third length L3 in the first direction of the region where the insulating layer, the first conductive layer, and the first external electrode overlap, and a fourth length L4 in the first direction of the region where the insulating layer, the second conductive layer, and the second external electrode overlap. The coil is preferably a wire-wound coil. It is preferable that the main body further includes a support substrate disposed inside the main body and including a first support surface and a second support surface facing each other, and the coil includes a first coil pattern disposed on the first support surface of the support substrate, a second coil pattern disposed on the second support surface of the support substrate, and a via connecting the first coil pattern and the second coil pattern. It is preferable that the main body is a laminate in which a plurality of sheets are stacked, and the coil includes a plurality of coil patterns arranged on each of the plurality of sheets and connected to each other. The external electrodes preferably include a first metal layer covering the conductive layer, a second metal layer covering the first metal layer, and a third metal layer covering the second metal layer. It is preferable that the first metal layer contains copper (Cu), the second metal layer contains nickel (Ni), and the third metal layer contains tin (Sn). Effect of the Invention

[0007] By using the configuration and structure of the coil electronic component according to the present invention, it is possible to provide a coil electronic component with an improved breakdown voltage (BDV). Also, it is possible to provide a coil electronic component having electrodes with improved flatness and ensuring a sufficient MUF gap. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a schematic configuration of a coil electronic component according to an embodiment of the present invention; [Diagram 2] 2 is a schematic cross-sectional view taken along line II-II' in FIG. 1. [Diagram 3] FIG. 13 is a perspective view showing a schematic configuration of a coil electronic component according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line IV-IV' in FIG. [Diagram 5] FIG. 11 is a cross-sectional view showing a schematic configuration of a coil electronic component according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, a specific example of an embodiment of a coil electronic component according to the present invention will be described with reference to the drawings.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the present invention. In order to clearly illustrate the present invention in the drawings, parts that are not necessary for the explanation are omitted, and the same reference numerals are used throughout the specification to refer to the same or similar components. In addition, in the accompanying drawings, some components are exaggerated, omitted, or illustrated diagrammatically, and the size of each component does not entirely reflect the actual size. The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and the attached drawings do not limit the technical ideas disclosed in this specification, and it should be understood that the drawings include all modifications, equivalents, and alternatives included in the idea and technical scope of the present invention.

[0011] Although terms including ordinal numbers such as first, second, etc. may be used to describe various components, the components are not limited by the terms. The terms are used only to distinguish one component from another. In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, there is no other part in between. Additionally, "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" in the direction against gravity.

[0012] Throughout the specification, the terms "comprise" or "have" and the like are intended to specify the presence of any feature, number, step, operation, component, part, or combination thereof described in the specification, and are to be understood as not precluding the presence or additional possibility of one or more other features, number, step, operation, component, part, or combination thereof. Thus, when a part is said to "comprise" certain elements, this does not mean to exclude other elements, but rather that it may further include other elements, unless specifically stated to the contrary. Also, throughout the specification, the term "in a plane" means when the subject part is viewed from above, and the term "in cross section" means when the subject part is cut vertically and viewed from the side. In addition, throughout the specification, when the term "connected" is used, this does not only mean that two or more components are directly connected, but also that two or more components are indirectly connected through other components, or that they are not only physically connected, but also electrically connected, or that they are referred to by different names depending on their position or function but are still one body.

[0013] FIG. 1 is a perspective view showing a schematic configuration of a coil electronic component according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line II-II' in FIG. 1 and 2, a coil electronic component 1000 according to an embodiment of the present invention includes a body 100, a coil 200, a supporting substrate 300, an insulating layer 400, a conductive layer 500, a first external electrode 700, and a second external electrode 800.

[0014] The main body 100 may be formed in a roughly rectangular parallelepiped shape, but the present embodiment is not limited thereto. During sintering, due to shrinkage of the magnetic powder and the like, the body 100 may have a substantially rectangular hexahedral shape, although not a perfect rectangular hexahedral shape. For example, the main body 100 may have a roughly rectangular hexahedral shape, but the corners and apexes may be rounded. In this embodiment, for ease of explanation, the two surfaces facing each other in the length direction (L axis direction) are defined as the first surface S1 and the second surface S2, the two surfaces facing each other in the width direction (W axis direction) are defined as the third surface S3 and the fourth surface S4, and the two surfaces facing each other in the thickness direction (T axis direction) are defined as the fifth surface S5 and the sixth surface S6.

[0015] The length of the coil electronic component 1000 means the maximum length of multiple line segments parallel to the length direction (L axis direction) by connecting the two outermost boundary lines facing each other in the length direction (L axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph taken with an optical microscope or a scanning electron microscope (SEM) of a length direction (L axis direction)-thickness direction (T axis direction) cross section at the center of the width direction (W axis direction) of the coil electronic component 1000. Alternatively, the length of the coil electronic component 1000 means the minimum value among the lengths of multiple line segments parallel to the length direction (L-axis direction) that connect the two outermost boundary lines facing each other in the length direction (L-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above. Alternatively, the length of the coil electronic component 1000 means the arithmetic average value of the lengths of at least two of the multiple line segments that connect the two outermost boundary lines facing each other in the longitudinal direction (L-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above and are parallel to the longitudinal direction (L-axis direction).

[0016] The thickness of the coil electronic component 1000 means the maximum length of multiple line segments parallel to the thickness direction (T axis direction) by connecting two outermost boundary lines facing each other in the thickness direction (T axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph taken with an optical microscope or a scanning electron microscope (SEM) of a longitudinal (L axis direction)-thickness (T axis direction) cross section at the center of the width direction (W axis direction) of the coil electronic component 1000. Alternatively, the thickness of the coil electronic component 1000 means the minimum value among the lengths of multiple line segments that connect the two outermost boundary lines facing each other in the thickness direction (T-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above and are parallel to the thickness direction (T-axis direction). Alternatively, the thickness of the coil electronic component 1000 means the arithmetic average value of the lengths of at least two of the multiple line segments that connect the two outermost boundary lines facing each other in the thickness direction (T-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above and are parallel to the thickness direction (T-axis direction).

[0017] The width of the coil electronic component 1000 means the maximum length of multiple line segments parallel to the width direction (W axis direction) by connecting the two outermost boundary lines facing each other in the width direction (W axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph taken with an optical microscope or a scanning electron microscope (SEM) of a longitudinal (L axis direction)-width direction (W axis direction) cross section at the center of the thickness direction (T axis direction) of the coil electronic component 1000. Alternatively, the width of the coil electronic component 1000 means the minimum value among the lengths of multiple line segments parallel to the width direction (W-axis direction) that connect the two outermost boundary lines facing each other in the width direction (W-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above. Alternatively, the width of the coil electronic component 1000 means the arithmetic average value of the lengths of at least two of the multiple line segments that connect the two outermost boundary lines facing each other in the width direction (W-axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph described above and are parallel to the width direction (W-axis direction).

[0018] Meanwhile, the length, width and thickness of the coil electronic component 1000 can also be measured by a micrometer measurement method. In the micrometer measurement method, the zero point is set with a micrometer that has been subjected to Gage R&R (Repeatability and Reproducibility), the coil electronic component 1000 according to this embodiment is inserted between the tips of the micrometer, and the measurement lever of the micrometer is turned to perform the measurement. Meanwhile, when measuring the length of the coil electronic component 1000 using a micrometer measurement method, the length of the coil electronic component 1000 may mean a value measured once, or may mean the arithmetic average of values ​​measured multiple times. This applies equally to the width and thickness measurements of the coil electronics 1000.

[0019] The body 100 forms the exterior of the coil electronic component 1000, and is a space in which a magnetic path is formed, which is a path through which magnetic flux induced in the coil 200 passes when a current is applied to the coil 200 through the first external electrode 700 and the second external electrode 800. The body 100 surrounds and encapsulates the coil 200 and the supporting substrate 300 and contains magnetic material. The body 100 contains magnetic particles with insulating material between the magnetic particles.

[0020] The magnetic substance includes a first metal magnetic powder, a second metal magnetic powder having a larger particle size than the first metal magnetic powder, and a third metal magnetic powder having a larger particle size than the second metal magnetic powder. The average particle size of the first metallic magnetic powder (D 50 ) is 0.1 μm or more and 0.2 μm or less, and the average particle size (D 50 ) is 1 μm or more and 2 μm or less, and the average particle size (D 50 ) may be greater than or equal to 25 μm and less than or equal to 30 μm. The magnetic particles are ferrite particles or metallic magnetic particles that exhibit magnetic properties. The ferrite particles may be at least one of spinel-type ferrites such as Mg-Zn-, Mn-Zn-, Mn-Mg-, Cu-Zn-, Mg-Mn-Sr-, and Ni-Zn-based ferrites, hexagonal-type ferrites such as Ba-Zn-, Ba-Mg-, Ba-Ni-, Ba-Co-, and Ba-Ni-Co-based ferrites, garnet-type ferrites such as Y-based ferrites, and Li-based ferrites.

[0021] The metal magnetic particles are composed of two or more types of powders having different compositions, and may include one or more types selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), cobalt (Co), molybdenum (Mo), aluminum (Al), niobium (Nb), copper (Cu) and nickel (Ni). For example, the metal magnetic particles may be at least one of pure iron, Fe-Si based alloys, Fe-Si-Al based alloys, Fe-Ni based alloys, Fe-Ni-Mo based alloys, Fe-Ni-Mo-Cu based alloys, Fe-Co based alloys, Fe-Ni-Co based alloys, Fe-Cr based alloys, Fe-Cr-Si based alloys, Fe-Si-Cu-Nb based alloys, Fe-Ni-Cr based alloys, and Fe-Cr-Al based alloys. Here, the different compositions of the metal magnetic particles may mean different contents. The metallic magnetic particles may be amorphous or crystalline. For example, the metal magnetic particles are Fe-Si-B-Cr based amorphous alloy, but the present embodiment is not limited thereto.

[0022] The metal magnetic particles have an average particle size of about 0.1 μm to 30 μm, but is not limited to this. In this specification, the average particle size is D 90 Or D 50 This refers to the particle size distribution expressed as: Particle size distribution is an index showing the ratio of particles of different sizes (particle diameters) contained in a particle group being measured, and is well known to ordinary engineers. D 50 (Particle size corresponding to 50% cumulative volume of particle size distribution) indicates the average particle size. The metallic magnetic particles may be two or more different types of metallic magnetic particles. Here, different types of metal magnetic particles means that the metal magnetic particles are distinguished from one another in at least one of the average particle size, composition, component ratio, crystallinity, and shape.

[0023] The insulating material may include, but is not limited to, epoxy, polyimide, liquid crystal polymer, and the like, either alone or in combination. The method for forming the body 100 is not particularly limited. For example, sheets of magnetic material may be placed on the top and bottom of the coil 200 and then compressed and cured to form the body 100 .

[0024] The support substrate 300 is disposed inside the main body 100 and supports the coil 200 . The support substrate 300 is formed of an insulating material including a thermosetting insulating resin such as an epoxy resin, a thermoplastic insulating resin such as a polyimide, or a photosensitive insulating resin, or is formed of an insulating material in which such an insulating resin is impregnated with a reinforcing material such as glass fiber or an inorganic filler. For example, the support substrate 300 is formed from an insulating material such as prepreg, ABF (Ajinomoto Build-up Film), FR-4, BT (Bismaleimide Triazine) film, or PID (Photo Imagable Dielectric) film, but the present embodiment is not limited thereto.

[0025] As the inorganic filler, at least one selected from the group consisting of silica (SiO2), alumina (Al2O3), silicon carbide (SiC), barium sulfate (BaSO4), talc (Talc), mud, mica powder, aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), magnesium carbonate (MgCO3), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO3), barium titanate (BaTiO3), and calcium zirconate (CaZrO3) may be used.

[0026] The support substrate 300 has a through-hole 310 in its center. The through hole 310 is filled with a magnetic material constituting the main body 100 to form a core, thereby improving the performance of the coil electronic component. The coil 200 is disposed inside the main body 100 and exerts the characteristics of the coil electronic component 1000 . For example, when the coil electronic component 1000 of the present embodiment is used as a power inductor, when a current is applied to the coil 200, it stores energy in the form of a magnetic field to maintain an output voltage, thereby stabilizing the power supply of an electronic device. The coil 200 is disposed on a first supporting surface 320 and a second supporting surface 330 of a supporting substrate 300 which face each other. The coil 200 includes a first coil pattern 210 and a second coil pattern 220 , and the first coil pattern 210 and the second coil pattern 220 are electrically connected through a via 230 .

[0027] The first coil pattern 210 is disposed on a first supporting surface 320 of the supporting substrate 300 and includes a first lead portion 213 . The first lead portion 213 is exposed from the first surface S 1 of the body 100 and is electrically connected to the first external electrode 700 . The second coil pattern 220 is disposed on a second supporting surface 330 of the supporting substrate 300 and includes a second lead portion 223 . The second lead portion 223 is exposed from the second surface S 2 of the body 100 and is electrically connected to the second external electrode 800 .

[0028] On the other hand, when the first coil pattern 210, the first extraction portion 213, and the via 230 are formed by plating on the first support surface 320 side of the support substrate 300, the first coil pattern 210, the first extraction portion 213, and the via 230 each include a seed layer such as an electroless plating layer and an electrolytic plating layer. Here, the electrolytic plating layer may have a single-layer structure or a multi-layer structure. The multi-layered electroplating layer may be formed in a conformal film structure in which one electroplating layer covers another electroplating layer, or in a shape in which one electroplating layer is laminated on only one side of another electroplating layer. The seed layer of the first coil pattern 210, the seed layer of the first lead-out portion 213, and the seed layer of the via 230 are integrally formed so that no boundaries are formed between them, but the present embodiment is not limited thereto. The electrolytic plating layer of the first coil pattern 210, the electrolytic plating layer of the first lead-out portion 213, and the electrolytic plating layer of the via 230 are integrally formed so that no boundaries are formed between them, but this embodiment is not limited to this. The above description also applies to the second coil pattern 220, the second lead-out portion 223, and the vias 230.

[0029] Each of the coil 200 and the vias 230 is formed from a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof, but the present embodiment is not limited thereto.

[0030] An insulating film IF is provided between the coil 200 and the main body 100 . The insulating film IF is formed along the surfaces of the support substrate 300 and the coil 200 . The insulating film IF is not present in the portion where the supporting substrate 300 and the coil 200 are connected to the external electrodes (700, 800). The insulating film IF is for insulating the coil 200 from the body 100, and may include a known insulating material such as Parylene. The insulating material contained in the insulating film IF can be any material and is not particularly limited. For example, the insulating film IF can be a polyurethane resin, a polyester resin, an epoxy resin, or a polyamide-imide resin. The insulating film IF is formed by a method such as, but not limited to, vapor phase deposition. For example, the insulating film IF can be formed by laminating insulating films on both sides of the support substrate 300 .

[0031] The insulating layer 400 is disposed on the sixth surface S6 of the body 100. The insulating layer 400 is spaced apart from the first surface S1 and the second surface S2 of the body 100, respectively. That is, the insulating layer 400 partially covers the sixth surface S6 of the main body 100. The insulating layer 400 is made of a thermoplastic resin such as polystyrene, vinyl acetate, polyester, polyethylene, polypropylene, polyamide, rubber, or acrylic; a thermosetting resin such as phenol, epoxy, urethane, melamine, or alkyd; a photosensitive resin; parylene; or SiO x or SiN x may include. The insulating layer 400 is formed through a process such as screen printing, pad printing, dipping, spray printing, or the like. For example, the insulating layer 400 may be formed by applying a liquid insulating resin onto the surface of the body 100, laminating an insulating film such as a dry film onto the surface of the body 100, or through a thin film process such as vapor phase deposition. In the case of an insulating film, ABF (Ajinomoto Build-up Film) or a polyimide film that does not contain a photosensitive insulating resin may be used.

[0032] The thickness of the insulating layer 400 may be greater than or equal to 3 μm and less than or equal to 25 μm. If the thickness of the insulating layer 400 is less than 3 μm, the insulating performance is degraded, and the breakdown voltage may decrease. If the thickness of the insulating layer 400 exceeds 25 μm, the increase in the breakdown voltage is limited, but the thickness of the coil electronic component 1000 is too thick, which may cause mounting defects or loss of electrical characteristics.

[0033] The conductive layer 500 covers a portion of the insulating layer 400 and includes a first conductive layer 510 and a second conductive layer 520 . The first conductive layer 510 and the second conductive layer 520 are spaced apart from each other and cover a portion of the insulating layer 400 . The first conductive layer 510 partially covers the sixth surface S6 of the body 100. That is, the first conductive layer 510 covers the area in the sixth surface S6 of the main body 100 between the insulating layer 400 and the first surface S1. The first conductive layer 510 covers a surface of the outer surface of the insulating layer 400 that is relatively close to the first surface S 1 of the main body 100 . Here, the outer surface of the insulating layer 400 refers to the surface of the insulating layer 400 that contacts the main body 100, that is, the surface that faces the inner surface. The outer surface of the insulating layer 400 is divided into two parts based on the center of the insulating layer 400, that is, a surface on the first surface S1 side of the body 100 and a surface on the second surface S2 side. The first conductive layer 510 partially covers the surface of the insulating layer 400 on the first surface S1 side.

[0034] The second conductive layer 520 partially covers the sixth surface S6 of the body 100. That is, the second conductive layer 520 covers the area in the sixth surface S6 of the main body 100 between the insulating layer 400 and the second surface S2. The second conductive layer 520 covers the surface of the outer surface of the insulating layer 400 that is relatively close to the second surface S2 of the main body 100. That is, the second conductive layer 520 partially covers the surface of the insulating layer 400 on the second surface S2 side. In this manner, both sides of the insulating layer 400 relative to the center thereof may be partially covered by the first conductive layer 510 and the second conductive layer 520, respectively. That is, the center of the insulating layer 400 is not covered by the conductive layer 500 .

[0035] Both side edges of the insulating layer 400 contact the first conductive layer 510 and the second conductive layer 520, respectively. The regions between the edges of the insulating layer 400 close to the first surface S1 of the body 100 and the first surface S1 of the body 100 in both side edges are covered with a first conductive layer 510. The regions between the edges of the insulating layer 400 close to the second surface S2 of the body 100 and the second surface S2 of the body 100 in both side edges are covered with a second conductive layer 520. The first conductive layer 510 and the second conductive layer 520 function as seed layers for forming the first external electrode 700 and the second external electrode 800 by plating. That is, the first external electrode 700 is formed by directly plating the first conductive layer 510 with a conductive metal, and the second external electrode 800 is formed by directly plating the second conductive layer 520 with a conductive metal. The first external electrode 700 and the second external electrode 800 formed by the direct plating method in which a conductive metal is grown using the first conductive layer 510 and the second conductive layer 520 as seed layers have a high degree of flatness, thereby ensuring a sufficient MUF gap.

[0036] The first conductive layer 510 and the second conductive layer 520 are formed through a process such as screen printing, pad printing, dipping, spray printing, or the like. The thickness of the first conductive layer 510 and the second conductive layer 520 may be greater than or equal to 1 μm and less than or equal to 25 μm. If the thickness of the first conductive layer 510 and the second conductive layer 520 is less than 1 μm, the first conductive layer 510 and the second conductive layer 520 are too thin to function adequately as a seed layer. That is, there may be areas where the plating layer is not formed, and the external electrodes may not be formed to a sufficient thickness in those areas. If the thickness of the first conductive layer 510 and the second conductive layer 520 exceeds 25 μm, the thickness of the coil electronic component 1000 may be too thick, resulting in mounting failure or deterioration of electrical characteristics.

[0037] The first external electrode 700 and the second external electrode 800 are provided outside the body 100 and connected to the coil 200 . That is, the first external electrode 700 and the second external electrode 800 are connected to the first lead-out portion 213 and the second lead-out portion 223 of the coil 200, respectively. The first external electrode 700 extends from the sixth surface S 6 of the body 100 to a portion of the first surface S 1 and is connected to the first lead-out portion 213 of the coil 200 . For example, the first external electrode 700 includes a first electrode pad 710 and a first connection part 720 .

[0038] The first electrode pad 710 is disposed on a sixth surface S6 of the body 100, and the first connection part 720 extends from the first electrode pad 710 to the first surface S1 of the body 100. The first lead-out portion 213 of the coil 200 is exposed to the first surface S 1 of the body 100 and is connected to the first connection portion 720 . This electrically connects the coil 200 to the first external electrode 700 . The first electrode pad 710 and the first connector 720 may be a monolithic structure. For example, the first electrode pad 710 and the first connection part 720 may be formed by plating. The second external electrode 800 extends from the sixth surface S 6 of the body 100 to a portion of the second surface S 2 and is connected to the second lead-out portion 223 of the coil 200 . For example, the second external electrode 800 includes a second electrode pad 810 and a second connection part 820 .

[0039] The second electrode pad 810 is disposed on a sixth surface S6 of the body 100, and the second connection part 820 extends from the second electrode pad 810 to a second surface S2 of the body 100. The second lead-out portion 223 of the coil 200 is exposed to the second surface S2 of the body 100 and is connected to the second connection portion 820. This electrically connects the coil 200 to the second external electrode 800 . The second electrode pad 810 and the second connector 820 may be a monolithic structure. For example, the second electrode pad 810 and the second connection part 820 may be formed by plating.

[0040] The first external electrode 700 includes a first metal layer 701 , a second metal layer 702 , and a third metal layer 703 . The first metal layer 701 contains copper (Cu) as a plating layer in contact with the first lead portion 213 of the coil 200 and the outer surface of the main body 100, that is, the first surface S1. In addition, the first metal layer 701 covers the first conductive layer 510 . On the other hand, the first metal layer 701 passes through the first conductive layer 510 and contacts a portion of the insulating layer 400 . The first metal layer 701 forms a first electrode pad 710 and a first connector 720 of the first external electrode 700 . The second metal layer 702 is a plating layer that covers the first metal layer 701 and contains nickel (Ni). The third metal layer 703 is a plating layer that covers the second metal layer 702 and contains tin (Sn). However, this embodiment is not limited to such a three-layer structure, and a two-layer structure in which only one metal layer is added on the first metal layer 701 is also possible.

[0041] The second external electrode 800 includes a first metal layer 801 , a second metal layer 802 , and a third metal layer 803 . The first metal layer 801 contains copper (Cu) as a plating layer in contact with the second lead portion 223 of the coil 200 and the outer surface of the main body 100, that is, the second surface S2. In addition, the first metal layer 801 covers the second conductive layer 520 . On the other hand, the first metal layer 801 passes through the second conductive layer 520 and contacts a portion of the insulating layer 400 . The first metal layer 801 forms a second electrode pad 810 and a second connector 820 of the second external electrode 800 . The second metal layer 802 is a plating layer that covers the first metal layer 801 and contains nickel (Ni). The third metal layer 803 is a plating layer that covers the second metal layer 802 and contains tin (Sn). However, this embodiment is not limited to such a three-layer structure, and a two-layer structure in which only one metal layer is added on the first metal layer 801 is also possible.

[0042] As described above, a portion of the insulating layer 400 is covered by the first conductive layer 510 and the second conductive layer 520 , the first conductive layer 510 is covered by the first external electrode 700 , and the second conductive layer 520 is covered by the second external electrode 800 . Therefore, the insulating layer 400, the conductive layer 500, and the external electrodes (700, 800) form a triple layer structure. That is, there is a first overlapping region A1 where the insulating layer 400, the first conductive layer 510, and the first external electrode 700 all overlap, and there is a second overlapping region A2 where the insulating layer 400, the second conductive layer 520, and the second external electrode 800 all overlap. Hereinafter, the first overlapping area A1 and the second overlapping area A2 will be referred to as "overlapping area" when they are referred to together.

[0043] When the coil electronics 1000 has a first length L1, the overlap region has a second length L2, and the ratio of the second length L2 to the first length L1 may be within a particular range. The first overlap region A1 has a third length L3, and the second overlap region A2 has a fourth length L4. Therefore, the second length L2 of the overlapping region is the sum of the third length L3 of the first overlapping region A1 and the fourth length L4 of the second overlapping region A2. The ratio (L2 / L1) of the second length L2 of the overlap region to the first length L1 of the coil electronic component 1000 (hereinafter referred to as the "ratio of the overlap region") may be 0.3 or more and 0.7 or less. If the overlapping area ratio (L2 / L1) is less than 0.3, the effect of blocking leakage current between the coil and the external electrode may not be large, and the effect of increasing the breakdown voltage may not be large. If the overlapping area ratio (L2 / L1) exceeds 0.7, the first external electrode 700 and the second external electrode 800 become too close to each other, which may increase the possibility of current leakage and reduce the breakdown voltage.

[0044] Here, L1 refers to the maximum length of multiple line segments parallel to the length direction (L axis direction) that connect the two outermost boundary lines facing each other in the length direction (L axis direction) of the coil electronic component 1000 shown in the cross-sectional photograph taken with an optical microscope or a scanning electron microscope (SEM) of a length direction (L axis direction)-thickness direction (T axis direction) cross section at the center of the width direction (W axis direction) of the coil electronic component 1000. L3 means the distance between two straight lines perpendicular to the length direction (L-axis direction) that pass through both side edges of the area where the insulating layer 400, the first conductive layer 510, and the first external electrode 700 overlap shown in the cross-sectional photograph above. L4 means the distance between two straight lines perpendicular to the length direction (L-axis direction) that pass through both side edges of the area where the insulating layer 400, the second conductive layer 520, and the second external electrode 800 overlap shown in the cross-sectional photograph above. L2 means the sum of L3 and L4 mentioned above.

[0045] As described above, the insulating layer 400 is disposed on the sixth surface S6 of the main body 100, but the insulating layer 900 is also disposed on other parts of the main body 100. For example, the insulating layer 900 is disposed on the third surface S3, the fourth surface S4, and the fifth surface S5 of the body 100. Furthermore, when the first external electrode 700 partially covers the first surface S1 of the main body 100 and the second external electrode 800 partially covers the second surface S2 of the main body 100, the insulating layer 900 is also disposed on the remaining portion of the first surface S1 and the remaining portion of the second surface S2. In this manner, the insulating layer 900 is disposed on at least a portion of the first surface S1, the second surface S2, the third surface S3, the fourth surface S4, the fifth surface S5, and the sixth surface S6 of the main body 100 to prevent electrical shorts between other electronic components and the external electrodes (700, 800). The insulating layer 900 can be used as a resist when forming the external electrodes 700 and 800 by electrolytic plating, but is not limited thereto.

[0046] FIG. 3 is a perspective view showing a schematic configuration of a coil electronic component according to another embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view taken along line IV-IV' in FIG. 3 and 4, the coil electronic component 2000 includes a body 1100, a coil 1200, an insulating layer 400, a conductive layer 500, a first external electrode 700, and a second external electrode 800.

[0047] Coil 1200 includes at least one turn of conductive wire. For example, the coil 1200 is formed by winding a metal (eg, copper (Cu) or silver (Ag)) wire whose surface is coated with an insulating material into a spiral shape. That is, the coil 1200 is a wire-wound coil. The coil 1200 is not limited to a single wire, but may be a twisted wire or may be made up of two or more wires. Coil 1200 is, but is not limited to, a circular coil. For example, the coil 1200 can be a variety of known coils, such as a rectangular coil. The cross section of the individual wires of the coil 1200 may have a variety of known shapes, such as a square, a circle, an oval, or a triangle. The coil 1200 is constructed from multiple layers.

[0048] The coil 1200 includes a first coil 1210 and a second coil 1220 . The first coil 1210 is connected to the second coil 1220 and is disposed on the upper side of the second coil 1220, that is, on the fifth surface S5 side of the main body 1100, to form a layer. The number of turns in the first coil 1210 and the number of turns in the second coil 1220 may be the same or different. The coil 1200 is formed into a planar helix and has multiple turns. For example, the first coil 1210 includes, from the inside to the outside of the body 1100, an innermost turn coil C1, at least one intermediate turn coil C2, and an outermost turn coil C3. The second coil 1220 also includes, from the inside to the outside of the body 1100, an innermost turn coil C1', at least one intermediate turn coil C2', and an outermost turn coil C3'.

[0049] An insulating film IF is provided along the surface of each of the multiple turns of the coil 1200 . The insulating film IF is for protecting and insulating the multiple turns of the first coil 1210 and the second coil 1220, and may include a known insulating material such as Parylene. The insulating material contained in the insulating film IF can be any material and is not particularly limited. For example, the insulating film IF can be a polyurethane resin, a polyester resin, an epoxy resin, or a polyamide-imide resin. The insulating film IF can be formed by a method such as, but not limited to, vapor phase deposition.

[0050] The coil 1200 includes a winding portion 1230 , a first lead portion 1213 , and a second lead portion 1223 . The winding portion 1230 is a portion in which the metal wire makes at least one turn. The first lead-out portion 1213 extends from one end of the winding portion 1230 and is exposed to a first surface S 1 of the body 1100 . The first lead portion 1213 is connected to the first external electrode 700 . The second lead-out portion 1223 extends from the other end of the winding portion 1230 and is exposed to the second surface S 2 of the body 1100 . The second lead portion 1223 is connected to the second external electrode 800 . The remaining components other than those described above are the same as the components of the coil electronic component shown in FIG. 1, so a duplicated description thereof will be omitted.

[0051] FIG. 5 is a cross-sectional view showing a schematic configuration of a coil electronic component according to another embodiment of the present invention. Referring to FIG. 5, the coil electronic component 3000 includes a body 2100, a coil 2200, an insulating layer 400, a conductive layer 500, a first external electrode 700, and a second external electrode 800. The main body 2100 is a laminate in which a plurality of sheets containing a magnetic material are laminated in the thickness direction (T-axis direction). The coil 2200 includes a number of coil patterns 2210 disposed on respective sheets and interconnected.

[0052] The coil 2200 has a first lead-out portion 2213 at one end and a second lead-out portion 2223 at the other end. The first lead-out portion 2213 is exposed from the first surface S 1 of the body 2100 and is connected to the first external electrode 700 . The second lead portion 2223 is exposed from the second surface S 2 of the body 2100 and is connected to the second external electrode 800 . The remaining components other than those described above are the same as the components of the coil electronic component shown in FIG. 1, so a duplicated description thereof will be omitted.

[0053] Specific embodiments of the present invention are presented below. However, the embodiments described below are merely intended to specifically illustrate or explain the invention, and should not be construed as limiting the scope of the invention.

[0054] Example [Manufacturing example: Manufacturing of coil electronic parts] Comparative Example 1 A coil electronic component is manufactured in which the first length L1 is 2500 μm and the second length L2 of the overlapping region is 0 μm. Comparative Example 2 This is the same as Comparative Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 250 μm. Comparative Example 3 This is the same as Comparative Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 500 μm. Example 1 A coil electronic component is manufactured in which the first length L1 is 2500 μm and the second length L2 of the overlapping region is 750 μm. Example 2 This is the same as Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 1230 μm. Example 3 This is the same as Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 1700 μm. Comparative Example 4 This is the same as Comparative Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 1850 μm. Comparative Example 5 This is the same as Comparative Example 1, except that the first length L1 is 2500 μm and the second length L2 of the overlapping region is 2000 μm.

[0055] [Experimental example: Breakdown voltage stability of coil electronic components] After manufacturing 50 coil electronic components each of Examples 1 to 3 and Comparative Examples 1 to 5, the ratio (L2 / L1) of the second length L2 of the overlapping region to the first length L1 of the coil electronic components and the breakdown voltage were measured, and the minimum breakdown voltage (BDV min ) was used as the standard to judge the breakdown voltage stability. That is, BDV min If the BDV is less than 200V, the stability is judged as “poor” and min When the voltage was 200V or higher, the stability was judged to be “good”. The results are summarized in Table 1 below.

[0056] [Table 1]

[0057] Referring to Table 1, the coil electronic components manufactured in Examples 1 to 3 had a minimum breakdown voltage of 200 V or more, and had good breakdown voltage stability. In the coil electronic components manufactured in Comparative Examples 1 to 5, the minimum breakdown voltage was shown to be less than 200 V, and the breakdown voltage stability was poor. This is because the ratio (L2 / L1) of the second length L2 of the overlapping region to the first length L1 of the coil electronic component was less than 0.3 (Comparative Examples 1 and 2) or exceeded 0.7 (Comparative Examples 4 and 5).

[0058] [Experimental example: Electrode flatness and MUF gap of coil electronic components] Ten coil electronic components each according to Example 1 and Comparative Example 1 were manufactured, and the ten point height of roughness profile (Rz) of the external electrodes and the size of the MUF gap were measured, and the results are summarized in Table 2 below. The ten-point average roughness (Rz) is a measure of the flatness of an electrode; the smaller the value, the flatter the electrode. If the electrodes are flat, the contact area with the lands (electrodes for mounting) increases, which is advantageous for mounting on a board.

[0059] The MUF gap is the size of the gap that exists between the insulating band portion of the coil electronic component (the area between the first external electrode and the second external electrode) and the substrate when the coil electronic component is mounted on the substrate. When modularized as a SiP (System in Package), multiple device components are mounted and then encapsulated with sealing materials such as EMC (Epoxy Molding Compound) and liquid underfill through a packaging process. At this time, a sufficient space (20±5μm) must be secured between the MUF gaps.

[0060] For example, if the MUF gap is 5 μm or less, the gap between the coil electronic component and the substrate is small and the sealing material does not flow easily, which may reduce the filling property and cause voids to be generated. The generated voids exist as defects in the package and can induce various defects such as poor thermal and mechanical reliability. In addition, if the MUF gap is 0 μm or less, the position of the coil electronic component may be distorted or raised when mounted on the board, resulting in a phenomenon in which one external electrode of the coil electronic component is fixed to the board while the other external electrode stands up away from the board (Manhattan effect or Tombstone defect).

[0061] [Table 2]

[0062] Referring to Table 2, the coil electronic component manufactured in Example 1 exhibited a lower 10-point average roughness (Rz) than the coil electronic component manufactured in Comparative Example 1. It can be seen that the flatness of the external electrodes of the coil electronic component manufactured in Example 1 is improved. Also, in the case of the coil electronic component manufactured in Example 1, it can be confirmed that a sufficient MUF gap was ensured.

[0063] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical scope of the present invention. [Explanation of symbols]

[0064] 1000, 2000, 3000 Coil Electronic Components 100, 1100, 2100 Main unit 200, 1200, 2200 coils 210 First coil pattern 220 Second coil pattern 230 Beer 213, 1213, 2213 1st drawer 223, 1223, 2223 2nd drawer 300 Support substrate 400, 900 Insulation layer 500 Conductive layer 510 First conductive layer 520 Second conductive layer 700 1st external electrode 701, 801 1st metal layer 702, 802 2nd metal layer 703, 803 Third metal layer 710 First electrode pad 720 1st connection part 800 2nd external electrode 810 Second electrode pad 820 2nd connection part 1210 First coil 1220 Second coil 1230 Winding section 2210 coil pattern C1, C1' Innermost turn coil C2, C2' Middle turn coil C3, C3' Outermost turn coil IF insulating film

Claims

1. A coil electronic component, a main body including a magnetic material, the main body having a first surface and a second surface facing a first direction, a third surface and a fourth surface facing a second direction and connecting the first surface and the second surface, and a fifth surface and a sixth surface facing the third direction and connecting the first surface and the second surface; a coil at least partially embedded in the body; an insulating layer disposed on the sixth surface of the body; a conductive layer covering a portion of the insulating layer; an external electrode covering the conductive layer and coupled to the coil; The coil electronic component has a first length L1 in the first direction, A coil electronic component characterized in that the ratio (L2 / L1) of a second length L2 in the first direction of the region where the insulating layer, the conductive layer, and the external electrode overlap to the first length L1 is 0.3 or more and 0.7 or less.

2. The coil electronic component according to claim 1 , wherein the insulating layer is spaced apart from the first surface and the second surface of the body.

3. The conductive layer is a first conductive layer covering the sixth surface between the insulating layer and the first surface of the body; 3. The coil electronics component of claim 2, further comprising: a second conductive layer covering the sixth surface between the insulating layer and the second surface of the body.

4. the first conductive layer and the second conductive layer are spaced apart from each other; the first conductive layer covers the first surface side of the insulating layer, The coil electronic component according to claim 3 , wherein the second conductive layer covers the second surface of the insulating layer.

5. The external electrode is a first external electrode covering the first conductive layer; 5. The coil electronic component according to claim 4, further comprising: a second external electrode covering the second conductive layer.

6. the first external electrode extends to the first surface of the body and is connected to the coil; The coil electronic component of claim 5 , wherein the second external electrode extends to the second surface of the body and is connected to the coil.

7. The second length L2 is a third length L3 in the first direction of a region where the insulating layer, the first conductive layer, and the first external electrode overlap; and a fourth length L4 in the first direction of an area where the insulating layer, the second conductive layer, and the second external electrode overlap.

8. 2. The coil electronic component according to claim 1, wherein the coil is a wire-wound coil.

9. a support substrate disposed within the body and including a first support surface and a second support surface facing each other; The coil is a first coil pattern disposed on the first support surface of the support substrate; a second coil pattern disposed on the second support surface of the support substrate; The coil electronic component according to claim 1 , further comprising a via connecting the first coil pattern and the second coil pattern.

10. The main body is a laminate in which a plurality of sheets are laminated, The coil electronic component according to claim 1 , wherein the coil includes a plurality of coil patterns disposed on each of the plurality of sheets and connected to each other.

11. The external electrode is a first metal layer covering the conductive layer; a second metal layer covering the first metal layer; 2. The coil electronic component according to claim 1, further comprising: a third metal layer covering the second metal layer.

12. the first metal layer includes copper (Cu); the second metal layer includes nickel (Ni); The coil electronic component according to claim 11 , wherein the third metal layer contains tin (Sn).

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