Patent Publication Number: US-10777351-B2

Title: Complex electronic component

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority to Korean Patent Application No. 10-2016-0066799, filed on May 30, 2016 with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a complex electronic component, and in more detail, to a complex electronic component having excellent durability so as to withstand electrostatic discharge (ESD). 
     BACKGROUND 
     Since a tendency to use metallic cases having conductivity in electronic devices has recently increased, there has been a growing need to prevent electric shorts from occurring in the interior and an electrical charge being transferred to the exterior of electronic devices. 
     In detail, there are an increasing number of cases in which the front surface of a portable electronic device is manufactured using a metal frame in order to improve the aesthetic properties and strength thereof. Therefore, there is an increased demand for a method to protect electronic components in the interior of electronic devices from being affected by an ESD on the exterior thereof or to protect users from receiving an electric shock caused by an internal power defect. 
     However, due to the miniaturization and integration of portable electronic devices, additional ESD protection devices or electric shock prevention devices have been difficult to provide. 
     SUMMARY 
     An aspect of the present disclosure provides a complex electronic component including an electrostatic discharge (ESD) protection portion having a vertically stacked structure and having excellent durability so as to withstand static electricity. 
     According to an aspect of the present disclosure, a complex electronic component comprises a body including a first external electrode and a second external electrode, disposed on an external surface thereof and a laminate; a plurality of first electrodes and a plurality of second electrodes, disposed in the laminate and electrically connected to the first external electrode and the second external electrode, respectively; a third electrode and a fourth electrode, disposed on the laminate to be spaced apart from each other and electrically connected to the first external electrode and the second external electrode, respectively; and an ESD discharge layer disposed between the third electrode and the fourth electrode. In addition, a distance between the third electrode and the fourth electrode is within a range of 30 μm to 60 μm. 
     According to an aspect of the present disclosure, a complex electronic component comprises a laminate including a first external electrode and a second external electrode, disposed on an external surface of the laminate; a first discharge electrode and a second discharge electrode, disposed on an upper surface of the laminate, connected to the first external electrode and the second external electrode, respectively, and disposed to be spaced apart from each other; an ESD discharge layer disposed between the first discharge electrode and the second discharge electrode; and a cover layer disposed to cover an upper portion of the laminate. 
    
    
     
       BRIEF DESCRIPTION OF THE 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 a complex electronic component according to an exemplary embodiment; 
         FIG. 2  is a cross-sectional view taken along line I-I′ of  FIG. 1  and a schematic cross-sectional view of a complex electronic component according to an exemplary embodiment; 
         FIG. 3  is a top view taken along line II-II′ of  FIG. 1  and a schematic top view of a complex electronic component according to an exemplary embodiment; 
         FIG. 4  is a perspective view of a complex electronic component according to an exemplary embodiment, while  FIG. 5  is a cross-sectional view taken along line III-III′ of  FIG. 4 ; and 
         FIG. 6  is a perspective view of a complex electronic component according to an exemplary embodiment, while  FIG. 7  is a cross-sectional view taken along line IV-IV′ of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described with reference to schematic views illustrating embodiments of the present disclosure. In the drawings, for example, due to manufacturing techniques and/or tolerances, modifications of the shape shown may be estimated. Thus, embodiments of the present disclosure should not be construed as being limited to the particular shapes of regions shown herein, for example, to include a change in shape results in manufacturing. The following embodiments may also be constituted by one or a combination thereof. 
     The contents of the present disclosure described below may have a variety of configurations and propose only a required configuration herein, but are not limited thereto. 
     A device portion of a complex electronic component of the present disclosure may be provided as a capacitor, an inductor, or a thermistor, but is not limited thereto. 
     However, in the present disclosure, a capacitor will be described as an example, in order to clarify a description thereof. 
       FIG. 1  is a schematic perspective view of a complex electronic component  100  according to an exemplary embodiment. 
     With reference to  FIG. 1 , a complex electronic component, according to an exemplary embodiment, may include a body having a device portion A and an ESD protection portion B as well as a first external electrode  111  and a second external electrode  112 , disposed on an external surface of the body. 
     The first external electrode  111  and the second external electrode  112  may be disposed on opposing surfaces of the body in a length direction. 
     The first external electrode  111  and the second external electrode  112  may include a plurality of metal layers. 
     In detail, the first external electrode  111  and the second external electrode  112  may include a first metal layer formed using a conductive paste including silver (Ag), nickel (Ni), or the like and a second metal layer and a third metal layer, formed using a plating process. 
     The first external electrode  111  and the second external electrode  112  may be electrically connected to a first electrode  121  and a second electrode  122 , to be subsequently described, and may be electrically connected to a third electrode  131  and a fourth electrode  132 . 
       FIG. 2  is a cross-sectional view taken along line I-I′ of  FIG. 1  and a schematic cross-sectional view of a complex electronic component according to a first exemplary embodiment. In addition,  FIG. 3  is a top view taken along line II-II′ of  FIG. 1  and a schematic top view of a complex electronic component according to an exemplary embodiment. 
     With reference to  FIGS. 2 and 3 , a complex electronic component  100 , according to the first exemplary embodiment, may include a device portion A and an ESD protection portion B. 
     The device portion A may include a laminate  101  and a first electrode  121  and a second electrode  122 , disposed in the laminate  101 . 
     The laminate  101  may be provided as a plurality of dielectric layers  102 , including a ferroelectric material, which are stacked, compressed, and sintered. In addition, each layer of the plurality of dielectric layers  102  may be integrated, so that each layer thereof may be indiscernible to the naked eye. 
     A dielectric layer  102  may be formed using a material having a perovskite structure, such as barium titanate (BaTiO 3 ), a ferroelectric material. However, in a case in which the device portion A is provided as an inductor, a magnetic material may be used. In a case in which the device portion A is provided as a thermistor, a material having properties in which a resistance thereof is changed depending on a temperature may be used. 
     The laminate  101  may include a plurality of first electrodes  121  and second electrodes  122 , disposed therein. 
     The first electrode  121  and the second electrode  122  may be formed in such a manner that a conductive paste including a conductive material is printed on a dielectric layer. However, in the case of an inductor, the first electrode  121  and the second electrode  122  may be provided as an electrode having a coil form. 
     A conductive material used in the first electrode  121  and the second electrode  122  may be provided as one selected from Ni, copper (Cu), Ag, and the like, but is not limited thereto. 
     The ESD protection portion B may be disposed on a surface of the device portion A, for example, an upper surface of the device portion A. 
     The ESD protection portion B may include an ESD discharge layer  150 , a cover layer  160 , a third electrode  131 , and a fourth electrode  132 . 
     The cover layer  160  may be disposed in an upper portion of the ESD protection portion B, and may include an insulating material. Since the cover layer  160  includes an insulating material, contact with a metal can may not have an influence on an upper portion of the complex electronic component  100 . Therefore, positional freedom may be increased in a case in which a printed circuit board (PCB) is designed. 
     The third electrode  131  may refer to a first discharge electrode, while the fourth electrode  132  may refer to a second discharge electrode. 
     The third electrode  131  and the fourth electrode  132  may be formed in such a manner that a conductive paste including Ag or Cu is printed. 
     However, in a case in which the third electrode  131  and the fourth electrode  132  are formed using a conductive paste, the third electrode  131  and the fourth electrode  132  may be damaged at a temperature of 700° C. or higher in a sintering process among processes of manufacturing the complex electronic component  100 . Therefore, the third electrode  131  and the fourth electrode  132  may be formed using an Ag-epoxy or a Cu-epoxy. The Ag-epoxy or the Cu-epoxy may refer to an epoxy resin including conductive powder. 
     A gap  135  may be disposed between the third electrode  131  and the fourth electrode  132 . The gap  135  may be provided as a rectangle including end portions of the third electrode  131  and the fourth electrode  132  as opposing sides. 
     In other words, the gap  135  may refer to a portion in which the third electrode  131  and the fourth electrode  132  are disposed to be spaced apart from each other. Therefore, a length of the gap  135  may refer to a distance between the third electrode  131  and the fourth electrode  132 . 
     The ESD discharge layer  150  may be disposed in the gap  135 , that is, between the third electrode  131  and the fourth electrode  132 . 
     The ESD discharge layer  150  may be formed using a paste for ESD in which at least one metal particle among Ag, Cu, Ni, and palladium (Pd) is mixed with at least one ceramic material of a silicon dioxide (SiO 2 ) and zinc peroxide (ZnO 2 ). 
     The ESD discharge layer  150  may have insulating properties at a voltage limit or lower. However, in a case in which a voltage higher than the voltage limit is applied thereto, an electric current may flow through a metal particle included in the ESD discharge layer  150 . 
     The voltage limit may be controlled through a content of a metal particle included in the ESD discharge layer  150 . 
     In other words, the ESD discharge layer  150  may be disposed in the gap  135 . Therefore, the device portion A may be prevented from being damaged, in a case in which static electricity or overvoltage, higher than the voltage limit, is applied thereto, an electric current flows between the third electrode  131  and the fourth electrode  132 , and static electricity or overvoltage is applied to the device portion A. 
     In a case in which static electricity or overvoltage flows through the third electrode  131  once, the fourth electrode  132 , or the ESD discharge layer  150 , the third electrode  131 , the fourth electrode  132 , or the ESD discharge layer  150  may withstand static electricity or overvoltage. However, in a case in which a phenomenon described above is repeated several times, the third electrode  131 , the fourth electrode  132 , or the ESD discharge layer  150  may be damaged. 
     Therefore, the capability in which the third electrode  131 , the fourth electrode  132 , or the ESD discharge layer  150  withstands static electricity or overvoltage several times may be referred to as durability. In addition, durability may need to be increased. 
     Table 1 below illustrates measures of turn-on characteristics and ESD durability according to a length (Da) of a gap, in a case in which a ratio (Wa/Wt) of a line width (Wa) of the third electrode  131  and the fourth electrode  132  with respect to a width (Wt) is more than 0.2 and less than 0.5. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Exemplary 
                   
                 Turn-on 
                   
               
               
                   
                 Embodiment 
                 Da (μm) 
                 Characteristics 
                 ESD Durability 
               
               
                   
                   
               
             
            
               
                   
                 1 
                 10 
                 ∘ 
                 x 
               
               
                   
                 2 
                 30 
                 ⊚ 
                 ⊚ 
               
               
                   
                 3 
                 40 
                 ⊚ 
                 ⊚ 
               
               
                   
                 4 
                 60 
                 ∘ 
                 ∘ 
               
               
                   
                 5 
                 80 
                 x 
                 x 
               
               
                   
                   
               
            
           
         
       
     
     Turn-on characteristics may refer to characteristics in which an electric current flows in an ESD protection portion when a voltage higher than a specific voltage (400V) is applied thereto. In addition, ESD durability may refer to a measure of a defect in the ESD protection portion after ESD is applied thereto under IEC-61000-4-2 Level 4 standard (8 kV), 100 times. 
     With reference to Table 1, in order to secure excellent turn-on characteristics and high ESD durability, the third electrode  131  and the fourth electrode  132  may be disposed so that a length (Da) of the gap  135  may be within a range of 30 μm to 60 μm. 
     In detail, in a case in which the ratio (Wa/Wt) of the line width (Wa) of the third electrode  131  and the fourth electrode  132  with respect to a width (Wt) of the body is more than 0.2 and less than 0.5, and the length (Da) of the gap  135  is within a range of 30 μm to 60 μm, the complex electronic component, according to an exemplary embodiment, may have excellent turn-on characteristics and high ESD durability. 
     In a case in which the length (Da) of the gap  135  is less than 30 μm, durability so as to withstand a high voltage repeatedly applied to the ESD discharge layer  150  or static electricity may be reduced, as illustrated in Exemplary Embodiment 1. In a case in which the length (Da) of the gap  135  is greater than 60 μm, a minimum voltage at which a high voltage or static electricity may be discharged may be increased. Therefore, turn-on characteristics may be degraded. In detail, a reaction to a high voltage or static electricity may be irregular. 
     Table 2 below illustrates measures of turn-on characteristics and ESD durability, according to the ratio (Wa/Wt) of the line width (Wa) of the third electrode  131  and the fourth electrode  132  with respect to the width (Wt), in a case in which the length (Da) of the gap  135  is greater than 30 μm and less than 60 μm. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Exemplary 
                   
                 Turn-on 
                   
               
               
                   
                 Embodiment 
                 Wa/Wt 
                 Characteristics 
                 ESD Durability 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 6 
                 0.1 
                 x 
                 x 
               
               
                   
                 7 
                 0.2 
                 ∘ 
                 ∘ 
               
               
                   
                 8 
                 0.4 
                 ⊚ 
                 ⊚ 
               
               
                   
                 9 
                 0.5 
                 ∘ 
                 ∘ 
               
               
                   
                 10 
                 0.6 
                 x 
                 ∘ 
               
               
                   
                   
               
            
           
         
       
     
     With reference to  FIG. 2 , in a case in which the ratio (Wa/Wt) of the line width (Wa) of the third electrode  131  and the fourth electrode  132 , with respect to the width (Wt) of the body, is formed to be 0.2 to 0.5, the complex electronic component, according to an exemplary embodiment, may have excellent turn-on characteristics and high ESD durability. 
     In other words, in a case in which Wa/Wt is more than 0.5, turn-on characteristics are likely to be degraded by short circuits. In a case in which Wa/Wt is less than 0.2, reactivity to a high voltage or static electricity may be reduced. Therefore, there may be a problem in which turn-on characteristics are degraded, and durability is also reduced. 
     Therefore, the complex electronic component, according to an exemplary embodiment, may have excellent turn-on characteristics and high ESD durability in such a manner that the ratio (Wa/Wt) of the line width (Wa) of the third electrode  131  and the fourth electrode  132 , with respect to the width (Wt) of the body, is formed to be 0.2 to 0.5. 
     Table 3 illustrates measures of turn-on characteristics and ESD durability according to a content of a ceramic particle, in a case in which a content of a metal particle is greater than 37 wt % and less than 48 wt % in an ESD discharge layer. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                   
                 Content of Ceramic 
                   
                   
               
               
                 Exemplary 
                 Particle (wt %) 
                 Turn-on 
                 ESD 
               
            
           
           
               
               
               
               
               
               
            
               
                 Embodiment 
                 SiO 2   
                 ZnO 2   
                 Total 
                 Characteristics 
                 Durability 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 11 
                 7.5 
                 0 
                 7.5 
                 ⊚ 
                 ∘ 
               
               
                 12 
                 12.0 
                 0 
                 12.0 
                 ∘ 
                 ∘ 
               
               
                 13 
                 17.0 
                 0 
                 17.0 
                 x 
                 x 
               
               
                 14 
                 7.5 
                 5.0 
                 12.5 
                 ∘ 
                 ∘ 
               
               
                 15 
                 10.0 
                 5.0 
                 15.0 
                 x 
                 x 
               
               
                   
               
            
           
         
       
     
     With reference to  FIG. 3 , in a case in which the ESD discharge layer contains 7.5 wt % to 12.5 wt % of a ceramic particle, based on a total weight of the ESD discharge layer, the complex electronic component, according to an exemplary embodiment, may have excellent turn-on characteristics and high ESD durability. 
     In a case in which the ESD discharge layer contains less than 7.5 wt % of a ceramic particle, uniformity of a form of the ESD discharge layer is difficult to maintain. Therefore, there may be a problem in which ESD durability is reduced by non-uniformity of the form of the ESD discharge layer. In addition, in a case in which uniformity of the form of the ESD discharge layer is not maintained, there may be a problem in which discharge characteristics of ESD are not uniform. 
     In a case in which the ESD discharge layer contains greater than 12.5 wt % of the ceramic particle, there may be a problem in which turn-on characteristics and ESD durability are degraded, simultaneously. 
     Therefore, the complex electronic component, according to an exemplary embodiment, may have excellent turn-on characteristics and high ESD durability in such a manner that the ESD discharge layer contains 7.5 wt % to 12.5 wt % of the ceramic particle. 
     In detail, in a case in which SiO 2  or ZnO 2  is used as the ceramic particle, there may not be a significant difference in results illustrated in Table 3. It could be determined that turn-on characteristics and ESD durability are affected by the content of the ceramic particle. Therefore, in a case in which a ceramic particle having properties similar to that of SiO 2  or ZnO 2 , besides SiO 2  or ZnO 2 , is used, the same result is expected to be produced. 
       FIG. 4  is a perspective view of a complex electronic component  200  according to another exemplary embodiment, while  FIG. 5  is a cross-sectional view taken along line III-III′ of  FIG. 4 . 
     A description of a composition of a complex electronic component  200 , according to a different exemplary embodiment, the same as that of a complex electronic component  100 , according to the exemplary embodiment described above, will be omitted. 
     With reference to  FIGS. 4 and 5 , the complex electronic component  200 , according to a different exemplary embodiment in the present disclosure, may include a laminate  201  having a first external electrode  211  and a second external electrode  212 , disposed on an external surface thereof, a first discharge electrode  231  and a second discharge electrode  232 , disposed on an upper surface of the laminate  201 , connected to the first external electrode  211  and the second external electrode  212 , respectively, and disposed to be spaced apart from each other, an ESD discharge layer  250  disposed between the first discharge electrode  231  and the second discharge electrode  232 , and a cover layer  260  disposed to cover an upper portion of the laminate  201 . 
     The laminate  201  may be provided as a plurality of dielectric layers  202 , including a ferroelectric material, which are stacked, compressed, and sintered. The laminate  201  may include a plurality of first electrodes  221  and second electrodes  222 , disposed therein. 
     A gap  235  may be disposed between the first discharge electrode  231  and the second discharge electrode  232 . The ESD discharge layer  250  may be disposed in the gap  235 , that is, between the first discharge electrode  231  and the second discharge electrode  232 . 
     The first external electrode  211  and the second external electrode  212  may include lowermost electrode layers  211   a  and  212   a  and plating layers  211   b  and  212   b  formed using the lowermost electrode layers  211   a  and  212   a  as a seed layer. 
     The complex electronic component  200 , according to the present exemplary embodiment, may include the lowermost electrode layers  211   a  and  212   a  to cover opposing surfaces of the laminate  201  in a length direction, and may include the first discharge electrode  231  and the second discharge electrode  232  on the laminate  201 . Subsequently, the cover layer  260  may be disposed to cover the upper portion of the laminate  201 , and the plating layers  211   b  and  212   b  may be formed using a plating process. Therefore, in a complex electronic component according to the present exemplary embodiment, the plating layers  211   b  and  212   b  may be disposed in a portion exposed outwardly of the first external electrode  211  and the second external electrode  212 . In addition, the plating layers  211   b  and  212   b  may not be formed in a region in which the cover layer  260  is in contact with the laminate  201 . 
     In the complex electronic component  200  according to the present exemplary embodiment, since the cover layer  260  acting as a protective layer is disposed on an upper surface of a final product, contact with a metal can may not have an influence on an upper surface thereof. Therefore, positional freedom may be increased in a case in which a PCB is designed. 
     In addition, after a laminate used as a device portion is completed, a complex electronic component including an ESD protection portion using a simple additional process may be manufactured. 
       FIG. 6  is a perspective view of a complex electronic component according to another exemplary embodiment, while  FIG. 7  is a cross-sectional view taken along line IV-IV′ of  FIG. 6 . 
     A description of a composition of a complex electronic component  300 , according to the present exemplary embodiment, which is the same as that regarding complex electronic component  100 , according to an exemplary embodiment described above, and a complex electronic component  200 , according to a different exemplary embodiment, will be omitted. 
     With reference to  FIGS. 6 and 7 , plating layers  311   b  and  312   b  may extend from a portion exposed outwardly of a first external electrode  311  and a second external electrode  312  to be disposed to cover opposing surfaces of a cover layer  360  in a length direction. Furthermore, plating layers  311   b  and  312   b  may extend to cover portions of an upper surface of the cover layer  360  in a thickness direction. 
     As set forth above, according to an exemplary embodiment, an complex electronic component may include an ESD protection portion and include an ESD discharge layer disposed between a first discharge electrode and a second discharge electrode, thus improving durability of the ESD protection portion to withstand static electricity. 
     In addition, a distance between the first discharge electrode and the second discharge electrode is within a range of 30 μm to 60 μm. Therefore, in a case in which static electricity is generated, an electric current may be prevented from being concentrated, thus improving durability of the ESD protection portion to withstand static electricity. 
     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 invention as defined by the appended claims.