Patent Publication Number: US-2010127302-A1

Title: Light emitting diode package

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of Korean Patent Application No. 10-2008-0119099 filed on Nov. 27, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to light emitting diode packages, and more particularly, to a light emitting diode package that can be mounted on an application without changing a lead pattern of the light emitting diode package when the light emitting diode package is connected to the application having leads whose number is different from that of the leads of the light emitting diode package. 
     2. Description of the Related Art 
     Light emitting diodes are semiconductor devices that generate light of various colors when a current is applied. When compared to filament-based light emitting devices, these light emitting diodes have a longer life span, low power consumption, excellent initial driving characteristics, high vibration resistance and high tolerance for repetitive power switching. Thus, there has been an increasing demand for light emitting diodes. 
     Recently, light emitting diode packages are being mounted onto various kinds of applications, such as vehicles, display boards or backlights. At this time, depending on the lead patterns of the applications, the number of leads in light emitting diode packages needs to be changed or light emitting diode packages need to be mounted onto different parts of the applications. 
     For example, when a light emitting diode has a lead including a two-terminal electrode consisting of an anode and a cathode, and a PCB of an application includes a four-terminal electrode consisting of three anodes and one cathode, the lead pattern of the light emitting diode package or the external electrode pattern of the PCB needs to be changed in order to provide an electrical connection. 
     In order to manufacture a light emitting diode package, a lead is disposed at the center of a mold, and molding materials are then injected into the mold. Therefore, a body has a larger thickness under the lead, which increases the thickness of the light emitting diode package. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a light emitting diode package that can be mounted to an application without changing a lead pattern of the light emitting package when the light emitting diode package is connected to an application having leads whose number is different from that of the leads of the light emitting diode package. 
     Another aspect of the present invention provides a light emitting diode package that is reduced in thickness by forming a lead, electrically connected to a light emitting diode, on the bottom of a body and connecting the body having the lead formed thereon to an adapter to thereby form a package. 
     According to an aspect of the present invention, there is provided a light emitting diode package including: a body receiving a light emitting diode; a lead electrically connected to the light emitting diode; and an adapter receiving a modified electrode electrically connected to the lead so that the polarity of the modified electrode is changed into the polarity of the lead, the adapter in which the body is received and fixed. 
     The lead may be an electrode extending from the bottom of the body to the edges thereof, and the modified electrode may include a conductive pad formed of conductive materials and a non-conductive pad formed of non-conductive materials so that the modified electrode is electrically connected to an external connection electrode. 
     A lead receiving groove may be provided within both sides of the adapter so that the lead is received in the lead receiving groove having the corresponding shape. 
     The adapter completely may cover the sides of the body. 
     The adapter may include a projection coupled and fixed to the top of the body being received. 
     A heat dissipation hole may be provided in a lower surface of the adapter. 
     A heat sink may be provided in the bottom of the adapter to dissipate heat generated from the light emitting diode. 
     According to an aspect of the present invention, there is provided a light emitting diode package including: a body having a lead electrically connected to a light emitting diode; and an adapter having the shape of a plate attached to the bottom of the body, and including a modified electrode allowing the lead to be electrically connected to an external connection electrode of an application having terminals whose number is different from the number of terminals of the lead. 
     The body and the adapter may have the same width. 
     The lead may be an electrode provided on a lower surface of the body, and the modified electrode includes three conductive pads formed of conductive materials and one non-conductive pad formed of non-conductive materials so that the modified electrode is electrically connected to the external connection electrode. 
     A heat dissipation hole may be provided in the lower surface of the adapter to dissipate heat generated from the light emitting diode. 
     A heat sink may be provided on the bottom of the adapter to dissipate heat generated from the light emitting diode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and other advantages of the present invention 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 illustrating a light emitting diode package according to an exemplary embodiment of the invention; 
         FIG. 2  is an exploded perspective view illustrating the light emitting diode package, shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 1 , taken along the line A-A′; 
         FIG. 4  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 1 , in which heat dissipation holes are formed; 
         FIG. 5  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 1 , in which a heat sink is additionally formed; 
         FIG. 6  is a schematic perspective view illustrating a light emitting diode package according to another exemplary embodiment of the invention; 
         FIG. 7  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 6 , taken along the line B-B′; 
         FIG. 8  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 6 , in which heat dissipation holes are formed; 
         FIG. 9  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 6 , in which a heat sink is formed; and 
         FIG. 10  is a schematic view illustrating how an adapter of a light emitting diode package according to an exemplary embodiment of the invention is connected to an external connection electrode. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may however be embodied in many different forms and should not be construed as 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 invention to those skilled in the art. 
     In the drawings, the same reference numerals will be used throughout to designate the same or like components. 
       FIG. 1  is a schematic perspective view illustrating a light emitting diode package according to an exemplary embodiment of the invention.  FIG. 2  is an exploded perspective view illustrating the light emitting diode package, shown in  FIG. 1 .  FIG. 3  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 1 , taken along the line A-A′. 
     Referring to  FIGS. 1 through 3 , a light emitting diode package  10  according to this embodiment includes a body  20 , a lead  24  and an adapter  40 . 
     A cavity  22  is formed within the body  20  so that a light emitting diode  25  can be mounted within the cavity  22 . The body is formed of resin and may be manufactured by injection molding. 
     The light emitting diode  25  is electrically connected to the lead that extends from the lower part of the body  20  to the edges thereof. In the drawings, the light emitting diode is electrically connected to the lead  24  by chip bonding. However, the invention is not limited thereto. The light emitting diode  25  may be electrically connected to the lead  24  by wire bonding. 
     The lead  24  includes two electrodes consisting of anode (positive) polarity and cathode (negative) polarity. The lead  24  may be mounted onto the body  20 , partially exposed to a lower surface of the body  20  and extend to the edges thereof. The larger the lead  24  is, the more heat generated from the light emitting diode can be dissipated. For this reason, it is preferable to manufacture a larger lead. 
     The adapter  40  has a modified electrode that is electrically connected to the lead  24  exposed to the bottom of the body  20 . Here, the modified electrode has polarity that changes according to the polarity of the lead  24  so that the modified electrode has the same polarity as the lead  24 . The adapter  40  accommodates the body  20 , not exposing the sides of the body  20 . The modified electrode is electrically connected to an external connection electrode (electrodes  74   a  and  74   b  in  FIG. 10 ) of an application  70 . 
     Particularly, when the external connection electrode of the application  70  is a four-terminal electrode (three anodes and one cathode), the modified electrode includes three conductive pads  44  formed of conductive materials and one non-conductive pad  48  formed of non-conductive materials that are formed on the adapter  40  so that the modified electrode is electrically connected to the external connection electrode. 
     Here, the number of leads and the number of terminals of the electrode connection electrode may be changed by a person skilled in the art. 
     A pad insertion hole  47  may be formed in the adapter  40  so that the conductive pad  44  or the non-conductive pad  48  may be inserted and fixed into the pad insertion hole  47 . 
     The adapter  40  includes a projection  42  that is coupled to the top of the body  20  being received. Since the projection  42  is formed of materials having elasticity, the projection  42  opens when receiving the body  20 , and closes after the body  20  is completely received. 
     The adapter  40  completely covers the edges of the body  20  to firmly support the body  20 . Further, the adapter  40  may have a lead receiving recess  46  formed in both sides thereof so that the lead  24  can be received in the lead receiving recess  46  having the shape corresponding to the lead  24 . 
       FIG. 4  is a cross-sectional view illustrating the adapter of the light emitting diode package, shown in  FIG. 1 , in which heat dissipation holes are formed.  FIG. 5  is a cross-sectional view illustrating the adapter of the light emitting diode package, shown in  FIG. 1 , in which a heat sink is formed. 
     Referring to  FIG. 4 , heat dissipation holes  50  through which heat generated from the light emitting diode  25  is dissipated to the outside are formed in the bottom of the adapter  40  of the light emitting diode package  10 . 
     The heat dissipation holes  50  may be evenly formed over the entire lower side of the adapter  40 . Alternatively, the number of heat dissipation holes  50  formed in a region of the lower side of the adapter  40  that is adjacent to the be light emitting diode  25  may be greater than that of heat dissipation holes  50  formed in other regions. 
     Referring to  FIG. 5 , heat sink insertion holes  52  may be formed in the bottom of the adapter  40  of the light emitting diode package  10  so that a heat sink  60 , including a metallic plate having excellent thermal conductivity, can be inserted into the heat sink insertion holes  52 . 
     By the use of the heat sink  60 , the area contacting the air increases to thereby dissipate heat generated from the light emitting diode to the outside. 
       FIG. 6  is a schematic perspective view illustrating a light emitting diode package according to another exemplary embodiment of the invention.  FIG. 7  is a cross-sectional view illustrating the light emitting diode package, shown in  FIG. 6 , taken along the line B-B′.  FIG. 8  is a cross-sectional view illustrating an adapter of the light emitting diode package, shown in  FIG. 6 , in which heat dissipation holes are formed.  FIG. 9  is a cross-sectional view illustrating the adapter of the light emitting diode package, shown in  FIG. 6 , in which a heat sink is formed. 
     Referring to  FIGS. 6 through 9 , the light emitting diode package  10  according to this embodiment may include the body  20  and the adapter  40 . 
     The body  20  having the lead  24  electrically connected to the light emitting diode  25  according to this embodiment is the same as the body  20 , as illustrated in the embodiment with reference to  FIGS. 1 through 5 . Thus, a detailed description thereof will be omitted. 
     The adapter  40  has the same width as the body  20 . The adapter  40  does not completely cover the sides of the body  20  but is formed into a single plate that is attached to the lower surface of the body  20 . 
     The body  20  and the adapter  40  have the same width. The lead  24  only extends along the lower surface of the body  20  but is not exposed to the edges of the body  20 . As a result, the width of the light emitting diode package  10  is reduced along the axial direction to facilitate an electrical connection with the application. 
     The configurations of the heat sink  60  and the heat dissipation holes  50 , formed in the bottom surface of the adapter  40 , are the same as those of the embodiment illustrated in  FIGS. 1 through 5 . Thus, a detailed description thereof will be omitted. 
       FIG. 10  is a schematic view illustrating how an adapter of a light emitting diode package according to an exemplary embodiment of the invention is connected to an external connection electrode. 
     When the light emitting diode package  10  is mounted onto the application  70 , such as a vehicle, a display board or a backlight, electrical connections between the lead  24  of the body  20 , a modified electrode of the adapter  40 , and an external connection electrode  74  of the application  70  will be described in detail with reference to  FIG. 10 . 
     The lead  24  of the body  20  includes a two-terminal electrode. The lead  24  includes a lead  24   a  having cathode polarity and a lead  24   b  having anode polarity. 
     The external connection electrode  74  of the application  70  is a four-terminal electrode and includes one electrode  74   a  having cathode polarity and three electrodes  74   b  having anode polarity. 
     The modified electrode of the adapter  40  includes one non-conductive pad  48  and three conductive pads  44  so that the modified electrode corresponds to the external connection electrode  74  of the application  70 . 
     The adapter  40  and the body  20  are electrically connected to each other to form one light emitting diode package  10 . The lead  24   a , having cathode polarity, is electrically connected to the one of the conductive pads  44  and the one non-conductive pad  48  of the modified electrode, so that the polarity of the one conductive pad  44  is changed into cathode polarity. That is, the light emitting diode package  10  has one cathode electrode  44   a.    
     Further, the lead  24   b , having anode polarity, is electrically connected to the other two conductive pads  44  of the modified electrode, so that the polarity of each of the two conductive pads  44  is changed into anode polarity. That is, the light emitting diode package  10  has two anode electrodes  44   b.    
     The two anode electrodes  44   b  of the light emitting diode package  10  are connected to the anode electrodes  74   b  of the application  70 . The one cathode electrode  44   a  is connected to the cathode electrode  74   a  of the application  70 . 
     The electrodes of the light emitting diode package  10  are electrically connected to the corresponding electrodes of the application  70 . Therefore, electrodes having different numbers of terminals can be connected to each other without using a separate adapter. 
     As set forth above, in the light emitting diode package according to the exemplary embodiment of the invention, when the light emitting diode package is connected to an application having leads whose number is different from that of the leads of the light emitting diode package, the light emitting diode package can be easily mounted onto the application without changing a lead pattern of the light emitting diode package. 
     Furthermore, in the light emitting diode package according to the exemplary embodiment of the invention, an electrical connection can be made without mounting, depending on the arrangement of the external connection terminal of the application. 
     In addition, in the light emitting diode package according to the exemplary embodiment of the invention, the lead can be attached without molding to thereby facilitate the manufacturing of the light emitting diode package. Since the body is not formed under the bottom surface of the lead, the thickness of the light emitting diode package can be reduced. 
     While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.