Patent Publication Number: US-11380475-B2

Title: Coil component

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of priority to Korean Patent Application No. 10-2018-0106426 filed on Sep. 6, 2018 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a coil component. 
     BACKGROUND 
     An inductor, a coil component, is a representative passive electronic component used together with a resistor and a capacitor in electronic devices. 
     As electronic devices are designed to have higher performance and to be reduced in size, electronic components used in electronic devices have been increased in number and reduced in size. 
     In the case of an inductor, an aspect ratio is increased to improve a performance, but there may be a limitation in increasing an aspect ratio. 
     SUMMARY 
     An aspect of the present disclosure is to provide a coil component configured to have multiple layers to increase the number of turns. 
     Another aspect of the present disclosure is to reduce costs of manufacturing a coil having multiple layers. 
     According to an aspect of the present disclosure, a coil component includes a body including a magnetic metal powder; an internal insulating layer buried in the body; an internal coil portion disposed on the internal insulating layer, and having turns of which cross-sectional areas increase towards the internal insulating layer from externally of the internal insulating layer; an external insulating layer covering the internal coil portion; an external coil portion disposed on the external insulating layer, and having a greater number of turns than a number of turns of the internal coil portion; a connection via penetrating through the external insulating layer and connecting the internal coil portion and the external coil portion; and an insulating film surrounding the internal insulating layer, the internal coil portion, the external insulating layer, and the external coil portion. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic diagram illustrating a coil component according to an exemplary embodiment in the present disclosure; 
         FIG. 2  is a cross-sectional diagram taken along line I-I′ in  FIG. 1 ; 
         FIG. 3  is a cross-sectional diagram taken along line II-II′ in  FIG. 1 ; 
         FIG. 4  is a diagram illustrating portion A in  FIG. 3  in magnified form; 
         FIGS. 5A and 5B  are diagrams illustrating an example of an internal coil portion provided in a coil component according to an exemplary embodiment in the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described as follows with reference to the accompanying drawings. The shape and size of constituent elements in the drawings may be exaggerated or reduced for clarity. 
     The terms used in the exemplary embodiments are used to simply describe an exemplary embodiment, and are not intended to limit the present disclosure. A singular term includes a plural form unless otherwise indicated. The terms used in the exemplary embodiments are used to simply describe an exemplary embodiment, and are not intended to limit the present disclosure. A singular term includes a plural form unless otherwise indicated. The terms, “include,” “comprise,” “is configured to,” etc. of the description are used to indicate the presence of features, numbers, steps, operations, elements, parts or combination thereof, and do not exclude the possibilities of combination or addition of one or more features, numbers, steps, operations, elements, parts or combination thereof. Also, the term. “disposed on,” “positioned on,” and the like, may indicate that an element is positioned on or below an object, and does not necessarily mean that the element is positioned on the object with reference to a gravity direction. 
     Herein, a lower side, a lower portion, a lower surface, and the like, are used to refer to a direction toward amounted surface of the fan-out semiconductor package in relation to cross sections of the drawings, while an upper side, an upper portion, an upper surface, and the like, are used to refer to an opposite direction to the direction. However, these directions are defined for convenience of explanation, and the claims are not particularly limited by the directions defined as described above. 
     It can be understood that when an element is referred to with “first” and “second”, the element is not limited thereby. The terms “first,” “second,” etc. may be used only for a purpose of distinguishing the element from the other elements, and may not limit the sequence or importance of the elements. In some cases, a first element may be referred to as a second element without departing from the scope of the claims set forth herein. Similarly, a second element may also be referred to as a first element. 
     The term “an exemplary embodiment” used herein does not refer to the same exemplary embodiment, and is provided to emphasize a particular feature or characteristic different from that of another exemplary embodiment. However, exemplary embodiments provided herein are considered to be able to be implemented by being combined in whole or in part one with another. For example, one element described in a particular exemplary embodiment, even if it is not described in another exemplary embodiment, may be understood as a description related to another exemplary embodiment, unless an opposite or contradictory description is provided therein. 
     The term “coupled to,” “combined to,” and the like, may not only indicate that elements are directly and physically in contact with each other, but also include the configuration in which the other element is interposed between the elements such that the elements are also in contact with the other component. 
     Sizes and thicknesses of elements illustrated in the drawings are indicated as examples for ease of description, and exemplary embodiments in the present disclosure are not limited thereto. 
     In the drawings, an L direction is a first direction or a length direction, a W direction is a second direction or a width direction, a T direction is a third direction or a thickness direction. 
     In the descriptions described with reference to the accompanied drawings, the same elements or elements corresponding to each other will be described using the same reference numerals, and overlapped descriptions will not be repeated. 
     In electronic devices, various types of electronic components may be used, and various types of coil components may be used between the electronic components to remove noise, or for other purposes. 
     In electronic devices, a coil component may be used as a power inductor, a high frequency inductor, a general bead, a high frequency bead, a common mode filter, and the like. 
       FIG. 1  is a schematic diagram illustrating a coil component according to an exemplary embodiment.  FIG. 2  is a cross-sectional diagram taken along line I-I′ in  FIG. 1 .  FIG. 3  is a cross-sectional diagram taken along line II-II′ in  FIG. 1 .  FIG. 4  is a diagram illustrating portion A illustrated in  FIG. 3  in magnified form.  FIGS. 5A and 5B  are diagrams illustrating examples of internal coil portion provided in a coil component according to an exemplary embodiment. 
     Referring to  FIGS. 1 to 5 , a coil component  1000  according to the exemplary embodiment may include a body  100 , an internal insulating layer  200 , an internal coil portion  300 , an external insulating layer  400 , an external coil portion  500 , a connection via  600 , an insulating film  700 , and external electrodes  800  and  900 . 
     The body  100  may form an exterior of the coil component  1000 , and may bury the internal insulating layer  200 , the internal coil portion  300 , the external insulating layer  400 , the external coil portion  500 , the connection via  600 , and the insulating film  700 . 
     The body  100  may have a hexahedral shape. 
     Referring to  FIG. 1 , the body  100  may include a first surface  101  and a second surface  102  opposing each other in a length direction L, a third surface  103  and a fourth surface  104  opposing each other in a width direction W, and a fifth surface  105  and a sixth surface  106  opposing each other in a thickness direction T. The first to fourth surfaces  101 ,  102 ,  103 , and  104  of the body  100  may be walls of the body  100  connecting the fifth surface  105  and the sixth surface  106  of the body  100 . In the description below, “both front and rear surfaces of the body” may refer to the first surface  101  and the second surface  102 , and “both side surfaces of the body” may refer to the third surface  103  and the fourth surface  104  of the body. 
     As an example, the body  100  may be configured such that the coil component  1000  on which the external electrodes  800  and  900  are formed may have a length of 2.0 mm, a width of 1.2 mm, and a thickness of 0.65 mm, but an exemplary embodiment of the coil component  1000  is not limited thereto. 
     The body  100  may include a magnetic material and a resin material. For example, the body  110  may be formed by layering one or more magnetic composite sheets including a magnetic material dispersed in a resin. Alternatively, the body  100  may have a structure different from the structure in which a magnetic material is dispersed in a resin. For example, the body  100  may be formed of a magnetic material such as a ferrite. 
     The magnetic material may be a ferrite or a magnetic metal powder. 
     The ferrite may include, for example, one or more materials among a spinel ferrite such as an Mg—Zn ferrite, an Mn—Zn ferrite, an Mn—Mg ferrite, a Cu—Zn ferrite, an Mg—Mn—Sr ferrite, an Ni—Zn ferrite, and the like, a hexagonal ferrite such as a Ba—Zn ferrite, a Ba—Mg ferrite, a Ba—Ni ferrite, a Ba—Co ferrite, a Ba—Ni—Co ferrite, and the like, a garnet ferrite such as a Y ferrite, and a Li ferrite. 
     The magnetic metal powder may include one or more selected from a 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 magnetic metal powder may be one or more among a pure iron powder, a Fe—Si alloy powder, a Fe—Si—Al alloy powder, a Fe—Ni alloy powder, a Fe—Ni—Mo alloy powder, Fe—Ni—Mo—Cu alloy powder, a Fe—Co alloy powder, a Fe—Ni—Co alloy powder, a Fe—Cr alloy powder, a Fe—Cr—Si alloy powder, a Fe—Si—Cu—Nb alloy powder, a Fe—Ni—Cr alloy powder, and a Fe—Cr—Al alloy powder. 
     The magnetic metal powder may be amorphous or crystalline. For example, the magnetic metal powder may be a Fe—Si—B—Cr amorphous alloy powder, but an exemplary embodiment of the magnetic metal powder is not limited thereto. 
     The ferrite and the magnetic metal powder may have an average diameter of 0.1 μm to 30 μm, but an example of the average diameter is not limited thereto. 
     The body  100  may include two or more types of magnetic materials dispersed in a resin. The notion that types of the magnetic materials are different may indicate that one of an average diameter, a composition, crystallinity, and a form of one of magnetic materials is different from those of the other magnetic material. 
     The body  100  may include a core  110  penetrating through the internal insulating layer  200 , the internal coil portion  300 , the external insulating layer  400 , and the external coil portion  500 . The core  110  may be formed by filling a through hole of the coil portion  200  with a magnetic composite sheet, but an exemplary embodiment thereof is not limited thereto. 
     The internal insulating layer  200  may be buried in the body  100 . The internal insulating layer  200  may support the internal coil portion  300  and the external coil portion  500 . 
     The internal insulating layer  200  may be 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 may be formed of an insulating material in which a reinforcing material such as a glass fiber or an inorganic filler is impregnated with such an insulating resin. For example, the internal insulating layer  200  may be formed of an insulating material such as prepreg, ajinomoto build-up film (ABF), FR-4, a bismaleimide triazine (BT) resin, a photoimageable dielectric (PID), and the like, but an example of the material of the internal insulating layer is not limited thereto. 
     As an inorganic filler, one or more materials selected from a group consisting of silica (SiO 2 ), alumina (Al 2 O 3 ), silicon carbide (SiC), barium sulfate (BaSO 4 ), talc, mud, a mica powder, aluminum hydroxide (Al(OH) 3 ), magnesium hydroxide (Mg(OH) 2 ), calcium carbonate (CaCO 3 ), magnesium carbonate (MgCO 3 ), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO 3 ), barium titanate (BaTiO 3 ), and calcium zirconate (CaZrO 3 ) may be used. 
     When the internal insulating layer  200  is formed of an insulating material including a reinforcing material, the internal insulating layer  200  may provide improved stiffness. When the internal insulating layer  200  is formed of an insulating material which does not include a glass fiber, the internal insulating layer  200  may be desirable to reducing an overall thickness of the coil component. 
     The internal insulating layer  200  in the exemplary embodiment may be manufactured using a raw material such as a copper clad laminate (CCL) in which metal films are attached to both surfaces of an insulating material, but an exemplary embodiment thereof is not limited thereto. 
     The internal coil portion  300  and the external coil portion  500  may be connected to each other through the connection via  600  and may function as a single coil. The internal coil portion  300  and the external coil portion  500  may be buried in the body  100  and may embody properties of a coil component. For example, when the coil component  1000  is used as a power inductor, the internal coil portion  300 , the external coil portion  500 , and the connection via  600  may store an electric field as a magnetic field such that an output voltage may be maintained, thereby stabilizing power of an electronic device. 
     The internal coil portion  300  may be disposed on the internal insulating layer  200 , and may have turns of which cross-sectional areas increase towards the internal insulating layer  200  from externally of the internal insulating layer  200 . The internal coil portion  300  in the exemplary embodiment may be formed by selectively etching a copper film of the copper clad laminate described above. As a copper etchant penetrates into a surface of the copper film, the closer to an insulating material the copper film of the copper clad laminate is, the less the time for which the copper film is exposed to the copper etchant. Due to the difference described above, the turns of the internal coil portion  300  remaining after selectively etching the copper film using the copper etchant may be formed to increase towards the internal insulating layer  200  from externally of the internal insulating layer  200 . 
     The internal coil portion  300  may include first and second internal coil patterns  310  and  320  respectively formed on both surfaces of the internal insulating layer  200  opposing each other, and a through-via  330  penetrating through the internal insulating layer  200  to connect the first and second internal coil patterns  310  and  320 . Thus, the internal coil portion  300  may be configured such that the first and second internal coil patterns  310  and  320  formed on both surfaces of the internal insulating layer  200  may be connected to each other through the through-via  330  penetrating through the internal insulating layer  200  and may form a single coil. 
     The internal coil portion  300  may include a first conductive layer  10  being in contact with the internal insulating layer  200 , a second conductive layer  30  disposed on the first conductive layer  10 , and a seed layer  20  disposed between the first conductive layer  10  and the second conductive layer  30 . In this case, the first and second internal coil patterns  310  and  320  each may include the first conductive layer  10 , the seed layer  20 , and the second conductive layer  30 . 
     The CCL may have a form in which copper films are attached to both surfaces of an insulating material, and may form the internal coil portion  300  through the selective etching process as described above. The copper films attached to both surfaces of the insulating material may be electrically connected to each other. For example, a through-via hole may be formed on the CCL using a laser drill or a mechanical drill to penetrate through both of the insulating material and the copper films attached to both surfaces of the insulating material, an electroless plating process may be performed to an overall surface of the CCL including an internal wall of the through-via hole to form the through-via  330 , and an electroplating layer may be formed on an overall surface of the CCL using an electroless plating layer as a seed layer. Thereafter, the first and second internal coil patterns  310  and  320  may be formed through the selective etching process described above. The electroless plating layer and the electroplating layer may form the through-via  330 . Also, the remaining portion of the copper film of the CCL may correspond to the first conductive layer  10 , the electroless plating layer may correspond to the seed layer  20 , and the electroplating layer may correspond to the second conductive layer  30 . The electroless plating layer and the electroplating layer each may include copper, but an exemplary embodiment is not limited thereto. 
       FIG. 4  illustrates the example in which a thickness of the first conductive layer  10  is the same as a thickness of the second conductive layer  30 , but an exemplary embodiment thereof is not limited thereto. A thickness of the second conductive layer  30  may be configured to be smaller or greater than a thickness of the first conductive layer  10 . Also, as illustrated in  FIGS. 5A and 5B , a shape of the internal coil portion and the number of turns of the internal coil portion may vary. 
     The external insulating layer  400  may cover the internal coil portion  300 . In the exemplary embodiment, as the internal coil portion  300  includes the first and second internal coil patterns  310  and  320  disposed on both surfaces of the internal insulating layer  200 , the external insulating layer  400  may include first and second external insulating layers  410  and  420  disposed on both surfaces of the internal insulating layer  200  to respectively cover the first and second internal coil patterns  310  and  320 . 
     The external insulating layer  400  may be 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 may be formed of an insulating material in which a reinforcing material such as a glass fiber or an inorganic filler is impregnated with such an insulating resin. For example, the internal insulating layer IL may be formed of an insulating material such as prepreg, ajinomoto build-up film (ABF), FR-4, a bismaleimide triazine (BT) resin, a photoimageable dielectric (PID), and the like, but an example of the material of the internal insulating layer is not limited thereto. 
     As an inorganic filler, one or more materials selected from a group consisting of silica (SiO 2 ), alumina (Al 2 O 3 ), silicon carbide (SiC), barium sulfate (BaSO 4 ), talc, mud, a mica powder, aluminum hydroxide (Al(OH) 3 ), magnesium hydroxide (Mg(OH) 2 ), calcium carbonate (CaCO 3 ), magnesium carbonate (MgCO 3 ), magnesium oxide (MgO), boron nitride (BN), aluminum borate (AlBO 3 ), barium titanate (BaTiO 3 ), and calcium zirconate (CaZrO 3 ) may be used. 
     When the external insulating layer  400  is formed of an insulating material including a reinforcing material, the external insulating layer  400  may provide improved stiffness. When the external insulating layer  400  is formed of an insulating material which does not include a glass fiber, the external insulating layer  400  may be desirable to reducing an overall thickness of the coil component. When the external insulating layer  400  includes a photosensitive insulating resin, the connection via  600  may be formed in fine form. 
     The external coil portion  500  may be disposed on the external insulating layer  400 , and may have a greater number of turns than the number of turns of the internal coil portion  300 . As the external coil portion  500  is configured to have a greater number of turns than the number of turns of the internal coil portion  300 , the external coil portion  500  may be useful for the coil component  1000  to embody coil properties. Thus, in the exemplary embodiment, coil properties of the coil component  1000  may mainly be embodied by the external coil portion  500  having a greater number of turns, and the internal coil portion  300  having a less number of turns may be an auxiliary element of the external coil portion  500 . 
     The external coil portion  500  may include first and second external coil patterns  510  and  520  respectively disposed on the first and second external insulating layers  410  and  420 . Thus, referring to  FIG. 2  and other diagrams, the external coil portion  500  may be formed in each of an upper portion and a lower portion of the internal insulating layer  200 . The connection via  600  connecting the external coil portion  500  and the internal coil portion  300  may be formed in each of an upper portion and a lower portion of the internal insulating layer  200 . 
     Ends  511  and  521  of the first and second external coil patterns  510  and  520  may be exposed to the first and second surfaces  101  and  102  of the body  100 . For example, the end  511  of the first external coil pattern  510  may be exposed to the first surface  101  of the body  100 , and the end  521  of the second external coil pattern  520  may be exposed to the second surface  102  of the body  100 . The ends  511  and  521  of the first and second external coil patterns  510  and  520  exposed to the first and second surfaces  101  and  102  of the body  100  may be in contact with and electrically connected to the external electrodes  800  and  900 . 
     At least one of the first and second external coil patterns  510  and  520  and the connection via  600  may include at least one conductive layer. 
     For example, when the first external coil pattern  510  and the connection via  600  are formed on the first external insulating layer  410  through a plating process, the first external coil pattern  510  and the connection via  600  each may include a seed pattern such as an electroless plating layer, and an electroplating layer. The electroplating layer may have a single-layer structure, or may have a multiple-layer structure. The electroplating layer having a multiple-layer structure may have a conformal film structure in which one of the electroplating layers is covered by the other electroplating layer, or may have a form in which one of the electroplating layers is disposed on one surface of the other plating layers. 
     A seed pattern of the first external coil pattern  510  and a seed pattern of the connection via  600  may be integrated with each other such that no boundary may be formed therebetween, but an exemplary embodiment thereof is not limited thereto. The electroplating layer of the first external coil pattern  510  and the electroplating layer of the connection via  600  may be integrated with each other such that no boundary may be formed therebetween, but an exemplary embodiment thereof is not limited thereto. 
     Referring to  FIGS. 2 and 3 , the first and second external coil patterns  510  and  520  may be formed on and protrude from the external insulating layer  400 . As another example, the first external coil pattern  510  may be formed on and protrude to an upper surface of the first external insulating layer  410 , and the second external coil pattern  520  may be buried in a lower surface of the second external insulating layer  420  and the lower surface of the second external coil pattern  520  may be exposed to a lower surface of the second external insulating layer  420 . 
     The internal coil portion  300 , the external coil portion  500 , and the connection via  600  may be formed of a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or alloys thereof, but an example of the material is not limited thereto. 
     The insulating film  700  may surround the internal insulating layer  200 , the internal coil portion  300 , the external insulating layer  400 , and the external coil portion  500 . The insulating film  700  may insulate the internal coil portion  300  and the external coil portion  500  from the body  100 , and may include an insulating material such as a parylene, and the like. A material included in the insulating film  700  is not limited to any particular material. The insulating film  700  may be formed through a method such as a vapor deposition process, or the like, but the method for forming the insulating film  700  is not limited thereto. The insulating film  700  may be formed by layering insulating films on both surfaces of the internal insulating layer  200  on which the external coil portion  500  is formed. 
     The first and second external electrodes  800  and  900  may be disposed on both front and rear surfaces of the body opposing each other, and may be connected to the external coil portion  500 . For example, the first external electrode  800  may be disposed on the first surface  101  of the body  100  and may be connected by being in contact with the end  511  of the first external coil pattern  510  exposed to the first surface  101  of the body  100 . The second external electrode  900  may be disposed on the second surface  102  of the body  100 , and may be connected by being in contact with the end  521  of the second external coil pattern  520  exposed to the second surface  102  of the body  100 . 
     The external electrodes  800  and  900  may have a single-layer structure or a multiple-layer structure. For example, the first external electrode  800  may include a first layer including copper (Cu), a second layer disposed on the first layer and including nickel (Ni), and a third layer disposed on the second layer and including tin (Sn). Alternatively, the first external electrode  800  may include a resin electrode layer formed by curing a conductive paste including a resin and a conductive powder, and a plating layer formed on the resin electrode layer. 
     The first and second external electrodes  800  and  900  each may be formed of a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), chromium (Cr), titanium (Ti), or alloys thereof, but an example of the material is not limited thereto. 
     As described above, in the coil component in the exemplary embodiment, by forming a coil having a multiple-layer structure including an internal coil portion and an external coil portion, the number of turns required for a product and an effective region of a coil may be secured. Thus, in the exemplary embodiment, the number of turns required for a product and an effective region of a coil may be secured in a simplified manner by configuring a coil to have a structure having two or more layers, rather than increasing an aspect ratio of a coil. 
     Further, by forming an internal coil portion by a subtractive method of which manufacturing costs are relatively low, the number of turns required for a product may be secured in lower costs and through a simplified process. 
     According to the aforementioned exemplary embodiments, the number of turns of a coil may easily be increased. 
     Further, according to the aforementioned exemplary embodiments, the number of turns of a coil may be increased in lower costs. 
     While the exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present invention as defined by the appended claims.