Patent Publication Number: US-9899149-B2

Title: Electronic component and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of priority to Korean Patent Application No. 10-2014-0189112 filed on Dec. 24, 2014, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to an electronic component and a method of manufacturing the same. 
     An inductor, an electronic component, is a representative passive element configuring an electronic circuit, together with a resistor and a capacitor, to remove noise. 
     The inductor is manufactured by forming internal coil patterns in a magnetic body including a magnetic material and forming external electrodes on outer surfaces of the magnetic body. 
     SUMMARY 
     An aspect of the present disclosure provides an electronic component in which exposure of internal coil patterns may be prevented and high inductance may be implemented, and a method of manufacturing the same. 
     According to an aspect of the present disclosure, an electronic component includes a magnetic body having first and second end surfaces opposing each other and first and second side surfaces connected to the first and second end surfaces, and first and second internal coil patterns disposed in the magnetic body, and including coil pattern portions having a spiral shape and lead portions connected to ends of the coil pattern portions and exposed to one surfaces of the magnetic body, respectively. The coil pattern portions are exposed to the first and second side surfaces. First and second side parts cover at least portions of the first and second side surfaces. 
     According to another aspect of the present disclosure, a method of manufacturing an electronic component includes forming a laminate by forming a plurality of first and second internal coil patterns including coil pattern portions having a spiral shape and lead portions connected to ends of the coil pattern portions, and stacking magnetic sheets on upper and lower portions of the first and second internal coil patterns, cutting the laminate to form individual electronic components in which the first and second internal coil patterns are embedded in a magnetic body of each individual electronic components, to expose the lead portions to first and second end surfaces of the magnetic body and to expose the coil pattern portions to first and second side surfaces of the magnetic body, and forming first and second side parts on the first and second side surfaces of the magnetic body, respectively. 
    
    
     
       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 perspective view of an electronic component according to an exemplary embodiment in the present disclosure so that internal coil patterns thereof are visible; 
         FIG. 2  is a cross-sectional view taken along line I-I′ of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view illustrating a magnetic body and first and second side parts of the electronic component according to the exemplary embodiment in the present disclosure; 
         FIG. 4  is a cross-sectional view taken along line II-II′ of  FIG. 1 ; 
         FIG. 5  is a top plan view of a magnetic body and first and second side parts of the electronic component according to an exemplary embodiment in the present disclosure; and 
         FIGS. 6A, 6B, 7, and 8  are views schematically illustrating a method of manufacturing an electronic component according to the exemplary embodiment in the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
     The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. 
     In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements. 
     Electronic Component 
     Hereinafter, an electronic component according to an exemplary embodiment, particularly, a thin film type inductor, will be described. However, the electronic component according to an exemplary embodiment is not necessarily limited thereto. 
       FIG. 1  is a schematic perspective view of an electronic component according to an exemplary embodiment so that internal coil patterns thereof are visible, and  FIG. 2  is a cross-sectional view taken along line I-I′ of  FIG. 1 . 
     Referring to  FIG. 1 , as an example of the electronic component, a thin film type inductor used in a power line of a power supply circuit is disclosed. 
     In the electronic component  100  according to an exemplary embodiment, a “length” direction refers to an “L” direction of  FIG. 1 , a “width” direction refers to a “W” direction of  FIG. 1 , and a “thickness” direction refers to a “T” direction of  FIG. 1 . 
     The electronic component  100 , according to an exemplary embodiment, includes a magnetic body  50 , internal coil patterns  40  embedded in the magnetic body  50 , first and second side parts  61  and  62  disposed at first and second side surfaces of the magnetic body  50 , and first and second external electrodes  81  and  82  disposed at outer surfaces of the magnetic body  50  to be connected to the internal coil patterns  40 . 
     The internal coil patterns  40  of the magnetic body  50  of the electronic component  100 , according to an exemplary embodiment, include first and second internal coil patterns  41  and  42  therein. 
     The first internal coil pattern  41  having a plane coil shape are formed on one surface of an insulating substrate  20  disposed in the magnetic body  50 , and the second internal coil patterns  42  having a plane coil shape are formed on the other surface of the insulating substrate  20  opposing one surface of the insulating substrate  20 . 
     The first and second internal coil patterns  41  and  42  are formed on the insulating substrate  20  through electroplating, but are not necessarily limited thereto. 
     The first and second internal coil patterns  41  and  42  may have a spiral shape, and the first and second internal coil patterns  41  and  42  formed on one surface and the other surface of the insulating substrate  20 , respectively, may be electrically connected to each other through a via (not illustrated) penetrating through the insulating substrate  20 . 
     The first and second internal coil patterns  41  and  42  and the via may contain a metal having excellent electric conductivity, such as silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt), and alloys thereof. 
     The first and second internal coil patterns  41  and  42  may be coated with an insulating layer (not illustrated), and thus they may not directly contact the magnetic material forming the magnetic body  50 . 
     For example, the insulating substrate  20  may be a polypropylene glycol (PPG) substrate, a ferrite substrate, or a metallic soft magnetic substrate. 
     The insulating substrate  20  may have a through-hole formed in a central portion thereof to penetrate through the central portion thereof, wherein the through-hole may be filled with a magnetic material to form a core part  55 . The core part  55  filled with the magnetic material thus is formed, thereby improving inductance (L). 
     Meanwhile, the insulating substrate  20  is not necessarily included in the magnetic body, and the internal coil patterns may be formed with a metal wire without including the insulating substrate. 
     The first and second internal coil patterns  41  and  42  may include coil pattern portions  43  and  44  having a spiral shape, and lead portions  46  and  47  connected to ends of the coil pattern portions  43  and  44  and exposed to one surface of the magnetic body  50 . 
     Referring to  FIG. 2 , the lead portions  46  and  47  may be formed by extending the one ends of the coil pattern portions  43  and  44 , and may be exposed to one surface of the magnetic body  50  to be connected to the first and second external electrodes  81  and  82  disposed in a direction toward the outside of the magnetic body  50 . 
     For example, as shown in  FIG. 2 , the lead portion  46  of the first internal coil pattern  41  may be exposed to one end surface of the magnetic body  50  in a length L direction, and the lead portion  47  of the second internal coil pattern  42  may be exposed to the other end surface of the magnetic body  47  in the length L direction. 
     However, the lead portions  46  and  47  of each of the first and second internal coil patterns  41  and  42  are not necessarily limited to being exposed as described above, and may be exposed to at least one surface of the magnetic body  50 . 
     The magnetic body  50  of the electronic component  100 , according to an exemplary embodiment, includes magnetic metal powder. However, the magnetic body  50  is not necessarily limited to containing the magnetic metal powder, and may contain any magnetic powder exhibiting magnetic characteristics. 
     The magnetic metal powder may be a crystalline or amorphous metal containing at least any one selected from the group consisting of iron (Fe), silicon (Si), boron (B), chrome (Cr), aluminum (Al), copper (Cu), niobium (Nb), and nickel (Ni). 
     For example, the magnetic metal powders may be an Fe—Si—B—Cr based amorphous metal. 
     The magnetic metal powder may be contained in a thermosetting resin such as an epoxy resin, polyimide, or the like, in a form in which it is dispersed in the thermosetting resin. 
       FIG. 3  is an exploded perspective view illustrating a magnetic body and first and second side parts of the electronic component according to the exemplary embodiment. 
     Referring to  FIG. 3 , the magnetic body  50  of the electronic component  100 , according to an exemplary embodiment, has first and second end surfaces S L1  and S L2  opposing each other in the length L direction, first and second side surfaces S W1  and S W2  connected to the first and second end surfaces S L1  and S L2 , respectively, and opposing each other in a width W direction, and first and second main surfaces S T1  and S T2  opposing each other in a thickness T direction. 
     The coil pattern portions  43  and  44  of the first and second internal coil patterns  41  and  42 , according to an exemplary embodiment, are exposed to the first and second side surfaces S W1  and S W2  of the magnetic body  50 . 
     The first and second side surfaces S W1  and S W2  to which the coil pattern portions  43  and  44  are exposed may be disposed with the first and second side parts  61  and  62 . 
     In another exemplary embodiment of an electronic component in which side parts are not attached to side surfaces of a magnetic body, the magnetic body includes margin parts having a predetermined interval in a direction toward side surfaces of the magnetic body in order to prevent exposure of the internal coil patterns to the side surfaces of the magnetic body. 
     However, due to a cutting deviation occurring at the time of cutting the laminate to form the magnetic body, the margin parts may not be appropriately formed, and an electrode exposure defect in which the internal coil patterns are exposed to the side surfaces of the magnetic body may occur. 
     In addition, a delamination defect rate may be increased due to an increase in electrode steps according to high current of the electronic component. 
     Accordingly, in an exemplary embodiment, the first and second side parts  61  and  62  may be disposed on the first and second side surfaces S W1  and S W2  of the magnetic body  50 . Therefore, electrode exposure defects may be prevented and delamination defects rate may be reduced. 
     In addition, in order to further attach the first and second side parts  61  and  62  on the first and second side surfaces S W1  and S W2  of the magnetic body  50 , the margin parts may not be needed in the magnetic body  50 , and therefore, the area of the internal coil  40  to be disposed may be significantly increased. As a result, high inductance is implemented. 
     The first and second side parts  61  and  62  are fixed onto the first and second side surfaces S W1  and S W2  of the magnetic body  50  to which the coil pattern portions  43  and  44  are exposed. 
     Boundaries among the magnetic body  50  and the first and second side parts  61  and  62  may be confirmed by using a scanning electron microscope (SEM). However, the magnetic body  50  and the first and second side parts  61  and  62  may not be necessarily classified by the boundaries observed by the SEM, and regions separately attached to the first and second side surfaces S W1  and S W2  of the magnetic body  50  may be classified as the first and second side parts  61  and  62 . 
     The first and second side parts  61  and  62  may include a thermosetting resin. 
     For example, the first and second side parts  61  and  62  may include a thermosetting resin such as an epoxy resin, a polyimide resin, or the like. However, the side parts are not necessarily limited to the above-described materials, and may be formed of any material exhibiting an insulation effect. 
     The first and second side parts  61  and  62  in the embodiment are formed by applying the thermosetting resin to the first and second side surfaces S W1  and S W2  of the magnetic body  50  to which the coil pattern portions  43  and  44  are exposed, and performing a hardening process, but the method of forming the side parts is not necessarily limited thereto. 
     The first and second side parts  61  and  62  may further include magnetic metal powder to implement higher inductance. 
     The first and second side parts  61  and  62  may include the magnetic metal powder having an amount of 3 wt % to 70 wt %. 
     When the first and second side parts  61  and  62  include less than 3 wt % of the magnetic metal powder, increased inductance may not be significant, and when the first and second side parts  61  and  62  include more than 70 wt % of the magnetic metal powder, increased rate of inductance may be small, and appearance defects may occur. 
     The first and second side parts  61  and  62  may be formed on the entire area of the first and second side surfaces S W1  and S W2  of the magnetic body  50 . 
     In order to effectively insulate the coil pattern portions  43  and  44  exposed to the first and second side surfaces S W1  and S W2 , the first and second side parts  61  and  62  may be formed on the entire area of the first and second side surfaces S W1  and S W2 . Meanwhile, the first and second side parts  61  and are not necessarily limited to being formed by the above-described methods, and may be formed only on a portion of the first and second side surfaces S W1  and S W2 . 
       FIG. 4  is a cross-sectional view taken along line II-II′ of  FIG. 1 . 
     Referring to  FIG. 4 , the coil pattern portions  43  and  44  of the first and second internal coil patterns  41  and  42  may be exposed to the first and second side surfaces S W1  and S W2  of the magnetic body  50 , and the first and second side parts  61  and  62  may be disposed on the first and second side surfaces S W1  and S W2 . 
     High inductance may be implemented since the internal coil  40  has a significantly increased area so that the coil pattern portions  43  and  44  are exposed to the first and second side surfaces S W1  and S W2  of the magnetic body  50 . 
     Each of the first and second side parts  61  and  62  may have a thickness t of 10 μm to 40 μm. 
     When the thickness t of the first and second side parts  61  and  62  is less than 10 μm, the coil pattern parts  43  and  44  exposed to the first and second side surfaces S W1  and S W2  may not be insulated, and when the thickness t of the first and second side parts  61  and  62  is more than 40 μm, a volume occupied by the first and second side parts  61  and  62  may be excessively increased, and therefore, it may be difficult to implement high inductance. 
       FIG. 5  is a top plan view of the magnetic body and first and second side parts of the electronic component according to an exemplary embodiment. 
     Referring to  FIG. 5 , in the electronic component according to an exemplary embodiment, with an area of a cross section of a core part  55  formed at an inner side of the first and second internal coil patterns  41  and  42  in a length-width L-W direction being a c , the sum of areas of cross sections of the magnetic body  50  at an outer side of the first and second internal coil patterns  41  and  42  in the length-width L-W direction being a e , and the sum of areas of cross sections of the first and second side parts  61  and  62  in the length-width L-W direction being a s , a e +a s ≦a c  may be satisfied. 
     Since the first and second side parts  61  and  62  are further attached on the first and second side surfaces S W1  and S W2  of the magnetic body  50 , the margin parts may not be needed in the magnetic body  50 , and therefore, the first and second internal coil patterns  41  and  42  may have a significantly increased area so that the coil pattern portions  43  and  44  are exposed to the first and second side surfaces S W1  and S W2  of the magnetic body  50 . 
     Accordingly, the area a c  of the core part  55  formed in the first and second internal coil patterns  41  and  42  may be increased, and a e +a s ≦a c  may be satisfied. 
     The electronic component according to an exemplary embodiment may satisfy a e +a s ≦a c  to implement high inductance. 
     Method of Manufacturing an Electronic Component 
       FIGS. 6A, 6B, 7, and 8  are views schematically illustrating a method of manufacturing an electronic component according to the exemplary embodiment. 
     Referring to  FIG. 6A , a plurality of first and second internal coil patterns  41  and  42  may be formed on one surface and the other surface of an insulating substrate  20 . 
     A via hole (not illustrated) may be formed in the insulating substrate  20 , a plating resist having an opening part may be formed on the insulating substrate  20 , and the via hole and the opening part may be filled with a conductive metal by plating to form the first and second internal coil patterns  41  and  42  and a via (not illustrated) connecting the first and second internal coil patterns. 
     The first and second internal coil patterns  41  and  42  and the via may be formed of a conductive metal having excellent electrical conductivity, such as silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), platinum (Pt), and alloys thereof. 
     Meanwhile, the formation of the internal coil patterns  41  and  42  is not necessarily limited to the above-described plating, and the internal coil patterns may be formed of a metal wire. 
     The first and second internal coil patterns  41  and  42  may include coil pattern portions  43  and  44  having a spiral shape, and lead portions  46  and  47  connected to ends of the coil pattern parts  43  and  44 . 
     Insulating layers (not illustrated) coating the first and second internal coil patterns  41  and  42  may be formed on the first and second internal coil patterns  41  and  42 . 
     The insulating layer (not illustrated) may be formed by a method well-known in the art such as a screen printing method, an exposure and development method of a photo-resist (PR), a spray applying method, or the like. 
     For example, the insulating substrate  20  may be a polypropylene glycol (PPG) substrate, a ferrite substrate, a metallic soft magnetic substrate, and the like. 
     The insulating substrate  20  may have a core part hole  55 ′ formed by removing a central portion of a region in which the first and second internal coil patterns  41  and  42  are not formed. 
     The insulating substrate  20  may be removed by mechanical drilling, laser drilling, sandblasting, punching, or the like. 
     Referring to  FIG. 6B , magnetic sheets  51  may be stacked on upper and lower portions of the first and second internal coil patterns  41  and  42  to form a laminate. 
     The magnetic sheets  51  may be manufactured in a sheet shape by mixing magnetic metal powder, a thermosetting resin, and organic materials such as a binder, a solvent, and the like, with each other to prepare slurry and applying and then drying the slurry at a thickness of several tens of micrometers on carrier films by a doctor blade method. 
     In the manufactured magnetic sheets  51 , the magnetic metal powder may be dispersed in the thermosetting resin such as an epoxy resin, polyimide, or the like. 
     The magnetic sheets  51  may be stacked, compressed and hardened to form the laminate in which the internal coil patterns  41  and  42  are embedded. 
     The core part hole  55 ′ may be formed with magnetic material to form a core part  55 . 
       FIG. 6B  illustrates stacking the magnetic sheets  51  to form the laminate  50  in which the internal coil patterns  41  and  42  are embedded. However, the laminate  50  is not necessarily limited to being formed by the above-described method, and may be formed by any method that may form a magnetic metal powder-resin composite in which the internal coil patterns are embedded. 
     Referring to  FIG. 7 , the laminate may be cut along a C 1 -C 1  cutting line to expose the coil pattern parts  43  and  44 . 
     Referring to  FIG. 8 , the first and second side parts  61  and  62  may be formed on surfaces to which the coil pattern parts  43  and  44  are exposed, and the laminate may be cut along a C 2 -C 2  cutting line to form individual electronic components in which the first and second internal coil patterns  41  and  42  are embedded in the magnetic body  50 . 
     A sequence of the formation of the first and second side parts  61  and  62  and the formation of the individual electronic components by cutting the laminate is not necessarily limited to the above-described sequence. 
     As illustrated in  FIG. 8 , the first and second side parts  61  and  62  may be formed and the laminate may be cut into the individual electronic components, or the laminate may be cut into the individual electronic components and the first and second side parts  61  and  62  may be formed. 
     In the cutting of the laminate, the lead portions  46  and  47  may be exposed to first and second end surfaces S L1  and S L2  of the magnetic body  50 , and the coil pattern parts  43  and  44  may be exposed to first and second side surfaces S W1  and S W2  of the magnetic body  50 . 
     According to a method of manufacturing an electronic component according to an exemplary embodiment, since the first and second side parts  61  and  62  are formed on the first and second side surfaces S W1  and S W2  of the magnetic body  50 , the margin parts may not be needed in the magnetic body  50 , and therefore, the first and second internal coil patterns  41  and  42  may have significantly increased areas. As a result, high inductance may be implemented. 
     The first and second side parts  61  and  62  may be formed by applying and hardening a thermosetting resin such as an epoxy resin, polyimide, or the like, on a surface to which the coil pattern parts  43  and  44  are exposed, but the first and second side parts  61  and  62  are not necessarily limited to being formed by the above-described methods. 
     The first and second side parts  61  and  62  may further include magnetic metal powder. The first and second side parts  61  and  62  may further include magnetic metal powder to implement higher inductance. 
     The first and second side parts  61  and  62  may include 3 wt % to 70 wt % of the magnetic metal powder. 
     When the first and second side parts  61  and  62  include less than 3 wt % of the magnetic metal powder, an increased inductance may not be significant, and when the first and second side parts  61  and  62  include more than 70 wt % of the magnetic metal powder, an increased rate of inductance may be small, and appearance defects may occur. 
     The first and second side parts  61  and  62  may have a thickness t of 10 μm to 40 μm. 
     When the thickness t of the first and second side parts  61  and  62  is less than 10 μm, the coil pattern parts  43  and  44  exposed to the first and second side surfaces S W1  and S W2  may not be insulated, and when the thickness t of the first and second side parts  61  and  62  is more than 40 μm, a volume occupied by the first and second side parts  61  and  62  may be excessively increased, and therefore, it may be difficult to implement high inductance. 
     A description of features overlapping with those of the electronic component according to the exemplary embodiment described above except for the above-mentioned description will be omitted. 
     As set forth above, according to exemplary embodiments, exposure of the internal coil patterns may be prevented and high inductance may be implemented. 
     While 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 disclosure as defined by the appended claims.