Patent Publication Number: US-2016240740-A1

Title: Led package having an array of light emitting cells coupled in series

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/599,932, filed on Jan. 19, 2015, which is a divisional of U.S. patent application Ser. No. 13/033,702, filed on Feb. 24, 2011, now issued as U.S. Pat. No. 8,937,326, which is a continuation of U.S. patent application Ser. No. 11/908,112, filed on Sep. 7, 2007, now issued as U.S. Pat. No. 8,076,680, which is the National Stage of PCT/KR2005/003565, filed on Oct. 26, 2005, and claims priority from and the benefit of Korean Patent Application Nos.: 10-2005-0026090, filed on Mar. 29, 2005; 10-2005-026078, filed on Mar. 29, 2005; 10-2005-0026067, filed on Mar. 29, 2005; 10-2005-0026108, filed on Mar. 29, 2005; and 10-2005-0020377, filed on Mar. 11, 2005, which are all hereby incorporated by reference for all purposes as if fully set forth herein. 
    
    
     BACKGROUND 
     1. Field 
     Exemplary embodiments of the present invention relate to a light emitting diode (LED) package, and more particularly, to an LED package having an array of light emitting cells coupled in series, which can be directly connected to and driven by an AC power source. 
     2. Discussion of the Background 
     Since light emitting diodes (LEDs) can realize colors, they have been widely used for indicating lamps, electric display boards and displays. The LEDs have also been used for general illumination because they can realize white light. Since such LEDs have high efficiency and longer life span and are environment-friendly, their applicable fields have been continuously expanded. 
     Meanwhile, an LED is a semiconductor device which is formed of a p-n junction structure of semiconductors and emits light through recombination of electrons and holes. In general, the LED is driven by a current flowing in a direction. Thus, when the LED is driven using an AC power source, there is a need for an AC/DC converter for converting an AC current to a DC current. With the use of an AC/DC converter together with LEDs, installation costs of LEDs increase, which makes it difficult to use the LEDs for general illumination at home. II) Therefore, to use LEDs for general illumination, there is a need for an LED package capable of being directly driven using an AC power source without an AC/DC converter. 
     Such an LED lamp is disclosed in U.S. Pat. No. 5,463,280 entitled “LIGHT EMITTING DIODE RETROFIT LAMP” issued to James C. Johnson. The LED lamp includes a plurality of light emitting diodes coupled in series, a means for limiting a current, and a diode bridge. Since an AC current is converted to a DC current through the diode bridge, the LED lamp can be driven by an AC power source. 
     However, since the LED lamp have serially coupled LEDs with individual LED chips mounted thereon, the process of coupling the LEDs is complicated, and the size of the LED lamp considerably increases since the LEDs occupy a large space. 
     In the meantime, since the luminous power of an LED is substantially in proportion to an input power, increase of electric power to be input into the LED enables high luminous power. However, the junction temperature of the LED increases due to the increase of the input electric power. The increase of the junction temperature of the LED results in decrease of photometric efficiency that represents the degree of conversion of input energy into visual light. Therefore, it is necessary to prevent the junction temperature of the LED from rising due to the increased input power. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art. 
     SUMMARY 
     An object of the present invention is to provide a light emitting diode (LED) package, which can be driven using an AC power source without an external AC/DC converter and thus can be miniaturized. 
     Another object of the present invention is to provide an LED package of which fabricating processes can be simplified and which is advantageous to mass production. 
     A further object of the present invention is to provide an LED package, which can improve photometric efficiency by easily dissipating generated heat and has a stable structure. 
     In order to achieve these objects of the present invention, the present invention provides an LED package having an array of light emitting cells coupled in series. An LED package according to an aspect of the present invention comprises a package body, and an LED chip mounted on the package body. The LED chip has an array of light emitting cells coupled in series. Since the LED package according to this aspect of the present invention mounts the LED chip having the array of light emitting cells coupled in series thereon, it can be driven directly using an AC power source. 
     Here, the term “light emitting cell” means a minute LED formed in a single LED chip. Although an LED chip generally has only one LED, the LED chip of the present invention has a plurality of light emitting cells. 
     In embodiments of the present invention, the LED chip comprises a substrate and a plurality of light emitting cells formed on the substrate. The light emitting cells are electrically insulated from the substrate. 
     In some embodiments of the present invention, the LED chip may comprise wires for electrically connecting the light emitting cells to one another in series. The array of light emitting cells coupled in series is formed by the light emitting cells and the wires. 
     In other embodiments of the present invention, a submount may be interposed between the LED chip and the package body. The submount may have electrode patterns corresponding to the light emitting cells, and the electrode patterns may couple the light emitting cells to one another in series. As a result, the array of light emitting cells coupled in series is formed by the light emitting cells and the electrode patterns. 
     Further, the LED chip may further comprise a rectification bridge unit for applying predetermined rectified power to the array of light emitting cells coupled in series. Accordingly, the LED chip can be driven using an AC power source. 
     Meanwhile, the LED chip may further comprise one or more arrays of light emitting cells coupled in series. The arrays of light emitting cells coupled in series may be connected to one another in reverse parallel. Accordingly, the LED chip can be driven using an AC power source without a rectification bridge unit or an AC/DC converter. 
     An encapsulant and/or a molding member may encapsulate the LED chip. The encapsulant and/or molding member protect the LED chip against moisture or external forces. The terms “encapsulant” and “molding member” herein are used without any differences from each other. However, in some embodiments, they are used together for discriminately referring to components. 
     Meanwhile, the LED package may further comprise a phosphor for converting the wavelength of light emitted from the LED chip. The phosphor may be incorporated in the molding member, or it may be located between the molding member and the LED chip, or on the molding member. With appropriate selection of the phosphor, it is possible to provide a LED package that can realize light with various colors or white light. 
     Meanwhile, the package body may have various structures. 
     For example, the package body may be a printed circuit board (PCB) with lead electrodes. The LED chip is electrically connected to the lead electrodes. In addition thereto, a reflective portion may be located on the PCB to reflect light emitted from the LED chip and incident thereon. 
     Moreover, the LED package may further comprise a pair of lead frames spaced apart from each other, and a heat sink. The package body supports the pair of lead frames and the heat sink. The package body may have an opening for exposing a portion of each of the lead frames and an upper portion of the heat sink. Meanwhile, the LED chip is mounted on the heat sink. By employing the heat sink, heat generated from the LED chip can be easily dissipated. 
     In some embodiments of the present invention, the heat sink may be connected directly to one of the lead frames at a side surface thereof and spaced apart from the other of the lead frames. Accordingly, the heat sink can be prevented from being separated from a package body, thereby providing an LED package that is stable in view of its structure. 
     In addition thereto, the heat sink may comprise a base and a protrusion protruding upwardly at a central portion of the base. Accordingly, the area of a heat dissipation surface increases so that heat can be easily dissipated and the size of an LED package can be minimized as well. The protrusion may protrude beyond a top surface of the package body. 
     Further, the heat sink may have a lead frame-receiving groove for receiving one of the lead frames at a side surface of the protrusion. The directly connected lead frame may be inserted into the lead frame-receiving groove. On the contrary, the heat sink and the lead frame connected directly to the heat sink may be formed integrally with each other. 
     In other embodiments of the present invention, the package body has a through-hole exposed through the opening. Further, the pair of lead frames have a pair of inner frames exposed inside the opening of the package body, and outer frames extending from the respective inner frames and protruding to the outside of the package body. In addition thereto, the heat sink is combined with a lower portion of the package body through the through-hole. 
     In addition, the heat sink may comprise a base combined with the lower portion of the package body, and a protrusion protruding upwardly at a central portion of the base and coupled with the through-hole. Further, the heat sink may have a latching step at a side surface of the protrusion. The latching step is caught by an upper surface of the package body or inserted into a sidewall defining the through-hole so that the heat sink is prevented from being separated from the package body. 
     According to another aspect of the present invention, there is provided an LED lamp on which an LED chip with an array of light emitting cells coupled in series is mounted. The LED lamp comprises a first lead having a top portion and a pin-type or snap-type leg extending from the top portion, and a second lead arranged to be spaced apart from the first lead and having a pin-type or snap-type leg corresponding to the first lead. The LED chip with the array of light emitting cells coupled in series is mounted on the top portion. Meanwhile, bonding wires electrically connect the LED chip to the first lead and the second lead, respectively. In addition, a molding member encapsulates the top portion of the first lead, the LED chip and a portion of the second lead. According to this aspect, by mounting the LED chip with the array of light emitting cells coupled in series, it is possible to provide an LED lamp that can be driven using an AC power source without an AC/DC converter. 
     The top portion of the first lead may have a cavity, and the LED chip may be mounted inside the cavity. 
     Meanwhile, if the first and second leads have pin-type legs, each of the first and second leads may have two pin-type legs. Such an LED lamp is generally known as a high flux LED lamp. Thus, according to this aspect, it is possible to provide a high flux LED lamp which can be driven using an AC power source. 
     Furthermore, a heat sink may extend from the top portion of the first lead in parallel with the leg of the first lead. The heat sink easily dissipates heat generated from the LED chip, thereby improving the photometric efficiency of the LED lamp. Further, the heat sink may have grooves on the surface thereof. The grooves increase the surface area of the heat sink, thereby more enhancing heat dissipation performance. 
     In embodiments of this aspect, the LED chip comprises a substrate and a plurality of light emitting cells formed on the substrate. The light emitting cells are electrically insulated from the substrate. 
     In some embodiments of this aspect, the LED chip may comprise wires for connecting the light emitting cells to one another in series. 
     In other embodiments of this aspect, a submount may be interposed between the LED chip and the top portion. The submount may have electrode patterns corresponding to the light emitting cells, and the electrode patterns may connect light emitting cells to one another in series. 
     Meanwhile, the LED chip may further comprises a rectification bridge unit for applying predetermined rectified power to the array of light emitting cells coupled in series. 
     Further, the LED chip may further comprise one or more arrays of light emitting cells coupled in series. The arrays of light emitting cells coupled in series may be connected to one another in reverse parallel. 
     Meanwhile, the LED lamp may further comprise a phosphor for converting the wavelength of light emitted from the LED chip. The phosphor may be dispersed in the molding member, or may be located between the molding member and the LED chip or on the molding member. 
     According to a further aspect of the present invention, there is provided an LED package having light emitting cells coupled in series. The LED package comprises a package body. A submount with electrode patterns is mounted on the package body. Meanwhile, the light emitting cells are bonded to the electrode patterns of the submount. At this time, the light emitting cells are coupled to one another in series through the electrode patterns. In addition thereto, a molding member may encapsulate the light emitting cells. 
     The package body may be a printed circuit board with lead electrodes, and the submount may be electrically connected to the lead electrodes. 
     Meanwhile, the LED package according to this aspect may further comprise a pair of lead frames spaced apart from each other, and a heat sink. The package body supports the pair of lead frames and the heat sink, and it may have an opening for exposing a portion of each of the lead frames and an upper portion of the heat sink. Further, the submount may be mounted on the heat sink. 
     According to a still further aspect of the present invention, there is provided an LED lamp having an array of light emitting cells coupled in series. The LED lamp comprises a first lead having a top portion and a pin-type or snap-type leg extending from the top portion, and a second lead arranged to be spaced apart from the first lead and having a pin-type or snap-type leg corresponding to the first lead. Meanwhile, a submount with electrode patterns is mounted on the top portion. In addition thereto, the light emitting cells are bonded to the electrode patterns of the submount. At this time, the light emitting cells are coupled to one another in series through the electrode patterns. Further, bonding wires electrically connect the submount to the first and second leads, respectively. Meanwhile, a molding member encapsulates the top portion of the first lead, the light emitting cells and a portion of the second lead. 
     According to the present invention, it is possible to provide an LED package and an LED lamp, which can be driven using an AC power source without an external AC/DC converter and thus can be miniaturized. Further, since light emitting cells formed on a single substrate are employed, the process of fabricating a package can be simplified and thus is advantageous to mass production. Moreover, since generated heat can be easily dissipated by employing the heat sink, the photometric efficiency of the light emitting cells can be improved. Furthermore, since the heat sink can be prevented from being separated from the package body, it is possible to provide an LED package that is stable in view of its structure. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the present invention, and together with the description serve to explain the principles of the present invention. 
         FIGS. 1 and 2  are sectional views illustrating light emitting diode (LED) chips each of which has an array of light emitting cells coupled in series, which are applicable to embodiments of the present invention. 
         FIGS. 3 to 5  are sectional views illustrating arrays of light emitting cells coupled in series through electrode patterns of a submount, which are applicable to embodiments of the present invention. 
         FIGS. 6 and 7  are circuit diagrams illustrating arrays of light emitting cells according to embodiments of the present invention. 
         FIGS. 8 to 10  are sectional views illustrating LED packages according to embodiments of the present invention. 
         FIG. 11  is a sectional view illustrating an LED package on which a plurality of light emitting devices with an array of light emitting cells coupled in series are mounted. 
         FIGS. 12 and 13  are sectional views illustrating LED packages each of which employs a heat sink, according to some embodiments of the present invention. 
         FIGS. 14 to 18  are views illustrating LED packages each of which employs a heat sink, according to other embodiments of the present invention. 
         FIGS. 19 to 23  are views illustrating LED packages each of which employs a heat sink, according to further embodiments of the present invention. 
         FIG. 24  is a sectional view illustrating an LED lamp having light emitting cells coupled in series according to an embodiment of the present invention. 
         FIGS. 25 to 32  are views illustrating high flux LED lamps according to other embodiments of the present invention. 
         FIG. 33  and  FIG. 34  are sectional views illustrating a light emitting device having a plurality of light emitting cells mounted on a submount substrate according to exemplary embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments. It is apparent, however, that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring various exemplary embodiments. 
     Unless otherwise specified, the illustrated exemplary embodiments are to be understood as providing exemplary features of varying detail of various exemplary embodiments. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions, and/or aspects of the various illustrations may be otherwise combined, separated, interchanged, and/or rearranged without departing from the disclosed exemplary embodiments. Further, in the accompanying figures, the size and relative sizes of layers, films, panels, regions, etc., may be exaggerated for clarity and descriptive purposes. When an exemplary embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. Also, like reference numerals denote like elements. 
     When an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it may be directly on, connected to, or coupled to the other element or layer or intervening elements or layers may be present. When, however, an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Further, the x-axis, the y-axis, and the z-axis are not limited to three axes of a rectangular coordinate system, and may be interpreted in a broader sense. For example, the x-axis, the y-axis, and the z-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms “first,” “second,” etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, and/or section from another element, component, region, layer, and/or section. Thus, a first element, component, region, layer, and/or section discussed below could be termed a second element, component, region, layer, and/or section without departing from the teachings of the present disclosure. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for descriptive purposes, and, thereby, to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of an apparatus in use, operation, and/or manufacture in addition to the orientation depicted in the drawings. For example, if the apparatus in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and, as such, the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Various exemplary embodiments are described herein with reference to sectional illustrations that are schematic illustrations of idealized exemplary embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments disclosed herein should not be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to be limiting. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein. 
     &lt;Array of Light Emitting Cells Coupled in Series&gt; 
     A light emitting diode (LED) package according to the present invention includes an array of light emitting cells coupled in series.  FIGS. 1 to 5  are sectional views illustrating arrays of light emitting cells coupled in series, which are applicable to embodiments of the present invention. Here,  FIGS. 1 and 2  are sectional views illustrating LED chips each of which has an array of light emitting cells coupled in series through wires,  FIGS. 3 and 5  are sectional views illustrating LED chips each of which has an array of light emitting cells coupled in series through electrode patterns of a submount, and  FIG. 4  is a sectional view illustrating an array of light emitting cells coupled in series through electrode patterns of a submount. 
     Referring to  FIGS. 1 and 2 , an LED chip of the present invention is formed on a substrate  20  and has a plurality of light emitting cells  100 - 1  to  100 - n  coupled to one another in series through wires  80 - 1  to  80 - n . That is, the LED chip comprises the plurality of light emitting cells  100  in which N-type semiconductor layers  40  and P-type semiconductor layers  60  of the adjacent light emitting cells  100 - 1  to  100 - n  are electrically connected, an N-type pad  95  is formed on the N-type semiconductor layer  40  of a light emitting cell  100 - n  located at one end of the LED chip, and a P-type pad  90  is formed on the P-type semiconductor layer  60  of a light emitting cell  100 - 1  located at the other end thereof. 
     The N-type semiconductor layers  40  and the P-type semiconductor layers  60  of the adjacent light emitting cells  100 - 1  to  100 - n  are electrically connected to each other through the metal wires  80  to form an array of the light emitting cells coupled in series. The light emitting cells  100 - 1  to  100 - n  can be coupled in series as many as the number of light emitting cells that can be driven by an AC power source. In the present invention, the number of the light emitting cells  100  coupled in series is selected according to a voltage/current for driving a single light emitting cell  100  and an AC driving voltage applied to an LED chip for illumination. 
     In the LED chip with first to n-th light emitting cells  100 - 1  to  100 - n  coupled in series, as shown in  FIG. 1 , the P-type pad  90  is formed on the P-type semiconductor layer  60  of the first light emitting cell  100 - 1 , and the N-type semiconductor layer  40  of the first light emitting cell  100 - 1  and the P-type semiconductor layer  60  of the second light emitting cell  100 - 2  are connected through a first wire  80 - 1 . Further, the N-type semiconductor layer  40  of the second light emitting cell  100 - 2  and the P-type semiconductor layer (not shown) of the third light emitting cell (not shown) are connected through a second wire  80 - 2 . An N-type semiconductor layer (not shown) of the (n−2)-th light emitting cell (not shown) and a P-type semiconductor layer  60  of the (n−1)-th light emitting cell  100 - n −1 are connected through an (n−2)-th wire  80 - n −2, and an N-type semiconductor layer  40  of the (n−1)-th light emitting cell  100 - n −1 and a P-type semiconductor layer  60  of the n-th light emitting cell  100 - n  are connected through an (n−1)-th wire  80 - n −1. Further, the N-type pad  95  is formed on the N-type semiconductor layer  40  of the n-th light emitting cell  100 - n.    
     The substrate  20  in the present invention may be a substrate on which a plurality of LED chips can be fabricated. Here, positions designated by “A” as shown in  FIGS. 1 and 2  refer to cutting positions for cutting the substrate into discrete LED chips. 
     Further, the aforementioned LED chip may have rectification diode cells for rectifying an external AC voltage. The diode cells are connected in the form of a rectification bridge to form a bridge rectifier. The bridge rectifier is arranged between an external power source and the array of light emitting cells coupled in series. Accordingly, a current flowing in a certain direction is supplied to the array of light emitting cells coupled in series. The rectification diode cells may have the same structures as those of the light emitting cells. In other words, the rectification diode cells may be formed through the same process as the light emitting cells. 
     Meanwhile, at least two arrays of light emitting cells coupled in series may be formed on the substrate. The arrays may be connected in reverse parallel to each other to be alternately driven by an AC power source. 
     A method of fabricating an LED chip having the light emitting cells coupled in series will be described below. 
     A buffer layer  30 , an N-type semiconductor layer  40 , an active layer  50  and a P-type semiconductor layer  60  are sequentially grown on a substrate  20 . A transparent electrode layer  70  may further be formed on the P-type semiconductor layer  60 . The substrate  20  may be a substrate made of sapphire (Al 2 O 3 ), silicon carbide (SiC), zinc oxide (ZnO), silicon (Si), gallium arsenide (GaAs), gallium phosphide (GaP), lithium-alumina (LiAl 2 O 3 ), boron nitride (BN), aluminum nitride (AlN) or gallium nitride (GaN), and the substrate  20  may be selected depending on the material of a semiconductor layer formed thereon. The substrate  20  may be a sapphire substrate or a silicon carbide (SiC) substrate in a case where a GaN based semiconductor layer is formed thereon. 
     The buffer layer  30  is a layer for reducing the lattice mismatch between the substrate  20  and the subsequent layers upon growth of crystals, and may be, for example, a GaN film. It is preferred that the buffer layer  30  is formed of an insulating layer in a case where a SiC substrate is a conductive substrate, and it may be formed of a semi-insulating GaN. The N-type semiconductor layer  40  is a layer in which electrons are produced and may be formed of an N-type compound semiconductor layer and an N-type cladding layer. At this time, the N-type compound semiconductor layer may be made of GaN doped with N-type impurities. The P-type semiconductor layer  60  is a layer in which holes are produced and may be formed of a P-type cladding layer and a P-type compound semiconductor layer. At this time, the P-type compound semiconductor layer may be made of AlGaN doped with P-type impurities. 
     The active layer  50  is a region in which a predetermined band gap and a quantum well are formed so that electrons and holes are recombined, and may include an InGaN layer. Further, the wavelength of emitted light, which is generated due to the recombination of an electron and a hole, varies depending on the kind of a material constituting the active layer  50 . Therefore, it is preferred that a semiconductor material comprised in the active layer  50  be controlled depending on a target wavelength. 
     Thereafter, the P-type semiconductor layer  60  and the active layer  50  are patterned such that a portion of the N-type semiconductor layer  40  is exposed, using lithographic and etching techniques. Also, the exposed portion of the N-type semiconductor layer  40  is partially removed to electrically isolate the light emitting cells  100  from each other. At this time, as shown in  FIG. 1 , a top surface of the substrate  20  may be exposed by removing an exposed portion of the buffer layer  30 , or the etching may be stopped at the buffer layer  30 . In a case where the buffer layer  30  is conductive, the exposed portion of the buffer layer  30  is removed to electrically isolate the light emitting cells. 
     By using the same process as the aforementioned fabricating process, diode cells for a rectification bridge may be formed at the same time. It will be apparent that diode cells for a rectification bridge may be separately formed through a typical semiconductor fabricating process. 
     Then, the conductive wires  80 - 1  to  80 - n  for electrically connecting the N-type semiconductor layers  40  and the P-type semiconductor layers  60  of the adjacent light emitting cells  100 - 1  to  100 - n  are formed through a predetermined process such as a bridge process or a step-cover process. The conductive wires  80 - 1  to  80 - n  are formed of a conductive material such as metal, silicon doped with impurities, or a silicon compound. 
     The bridge process is also referred to as an air bridge process, and this process will be described in brief. First, a photoresist is provided on a substrate having light emitting cells formed thereon, and a first photoresist pattern having openings for exposing the exposed portion of the N-type semiconductor layer and the electrode layer on the P-type semiconductor layer is then formed using an exposure technique. Thereafter, a metal material layer with a small thickness is formed using an e-beam evaporation technique or the like. The metal material layer is formed on entire top surfaces of the openings and photoresist pattern. Subsequently, a second photoresist pattern for exposing regions between the adjacent light emitting cells to be connected to one another as well as the metal material layer on the openings is formed again on the first photoresist pattern. Thereafter, gold is formed using a plating technique, and the first and second photoresist patterns are then removed. As a result, wires for connecting the adjacent light emitting cells to one another are left, and all the other metal material layers and photoresist patterns are removed so that the wires can connect the light emitting cells to one another in the form of bridges as shown in the figures. 
     Meanwhile, the step-cover process includes the step of forming an insulating layer on a substrate with light emitting cells. The insulating layer is patterned using lithographic and etching techniques to form openings for exposing the N-type semiconductor layer and the electrode layer on the P-type semiconductor layer. Subsequently, a metal layer for filling the openings and covering the insulating layer is formed using an e-beam evaporation technique or the like. Thereafter, the metal layer is patterned using lithographic and etching techniques to form wires for connecting the adjacent light emitting cells to one another. It is possible to make various modifications to such a step-cover process. Upon use of the step-cover process, the wires are supported by the insulating layer, thereby improving the reliability of the wires. 
     Meanwhile, the P-type pad  90  and the N-type pad  95  for electrical connection with the outside are formed on the light emitting cells  100 - 1  and  100 - n  located at both ends of the LED chip, respectively. Bonding wires (not shown) may be connected to the P-type pad  90  and N-type pad  95 . 
     The aforementioned method of fabricating the LED chip of the present invention is only a specific embodiment and is not limited thereto. Various modifications and additions can be made thereto depending on features of a device and convenience of a process. 
     For example, a plurality of vertical light emitting cells each of which has an N-type electrode, an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a P-type electrode sequentially laminated one above another are formed on a substrate, or light emitting cells having such a structure are arrayed by being bonded on the substrate. Then, the plurality of light emitting cells are coupled in series by connecting the N-type electrodes and P-type electrodes of the adjacent light emitting cells to one another, thereby fabricating an LED chip. It will be apparent that the vertical light emitting cell is not limited to the structure of the aforementioned example but may have various structures. Further, it is possible to form a plurality of light emitting cells on an additional host substrate by forming the plurality of light emitting cells on a substrate, bonding the light emitting cells on the host substrate, and separating the substrate using a laser or removing it using a chemical mechanical polishing technique. Thereafter, the adjacent light emitting cells can be coupled in series through wires. 
     Each of the light emitting cells  100  comprises the N-type semiconductor layer  40 , the active layer  50  and the P-type semiconductor layer  60 , which are sequentially laminated on a substrate  20 , and the buffer layer  30  is interposed between the substrate  20  and the light emitting cell  100 . Each of the light emitting cells  100  comprises the transparent electrode layer  70  formed on the P-type semiconductor layer  60 . Further, in case of a vertical light emitting cell, it comprises an N-type electrode located beneath the N-type semiconductor layer. 
     The N-type pad and P-type pad are pads for use in electrically connecting the light emitting cell  100  to an external metal wire or bonding wire, and may be formed as a laminated structure of Ti/Au. Further, electrode pads for connection to the wires  80  may be formed on the P-type and N-type semiconductor layers of the light emitting cells  100 . In addition, the aforementioned transparent electrode layer  70  distributes an input current such that the current is uniformly input into the P-type semiconductor layer  60 . 
     The LED chip described with reference to  FIGS. 1 and 2  has the array of light emitting cells  100  coupled in series through the wires  80 . However, there are various methods of coupling the light emitting cells in series. For example, light emitting cells may be coupled in series using a submount.  FIGS. 3 to 5  are sectional views illustrating arrays of light emitting cells coupled in series using submounts. 
     Referring to  FIG. 3 , an LED chip  1000  has a plurality of flip-chip type light emitting cells arrayed on a substrate  110 . Each of the light emitting cells comprises an N-type semiconductor layer  130  formed on the substrate  110 , an active layer  140  formed on a portion of the N-type semiconductor layer  130  and a P-type semiconductor layer  150  formed on the active layer  140 . Meanwhile, a buffer layer  120  may be interposed between the substrate  110  and the light emitting cell. At this time, an additional P-type electrode layer  160  for reducing the contact resistance of the P-type semiconductor layer  150  may be formed on the P-type semiconductor layer  150 . Although the P-type electrode layer may be a transparent electrode layer, it is not limited thereto. Moreover, the LED chip  1000  further comprises a P-type metal bumper  170  for bumping formed on the P-type electrode layer  150  and an N-type metal bumper  180  for bumping formed on the N-type semiconductor layer  130 . Furthermore, a reflective layer (not shown) having a reflectivity of 10 to 100% may be formed on the top of the P-type electrode layer  160 , and an additional ohmic metal layer for smooth supply of a current may be formed on the P-type semiconductor layer  150 . 
     The substrate  110 , the buffer layer  120 , the N-type semiconductor layer  130 , the active layer  140  and the P-type semiconductor layer  150  may be formed of the substrate  20  and the semiconductor layers described with reference to  FIGS. 1 and 2 . 
     A submount  2000  comprises a submount substrate  200  having a plurality of N-regions and P-regions defined thereon, a dielectric film  210  formed on the surface of the submount substrate  200 , and a plurality of electrode patterns  230  for connecting adjacent N-region and P-region to each other. Further, the submount  2000  further comprises a P-type bonding pad  240  located at an edge of the substrate, and an N-type bonding pad  250  located at the other edge thereof. 
     The N-regions refer to regions to which the N-type metal bumpers  180  in the LED chip  1000  are connected, and the P-regions refer to regions to which the P-type metal bumpers  170  in the LED chip  1000  are connected. 
     At this time, a substrate with superior thermal conductivity is used as the submount substrate  200 . For example, a substrate made of SiC, Si, germanium (Ge), silicon germanium (SiGe), AlN, metal and the like can be used. The dielectric film  210  may be formed as a multi-layered film. In a case where the substrate is conductive, the dielectric film  210  may be omitted. The dielectric film  210  may be made of silicon oxide (SiO 2 ), magnesium oxide (MgO) or silicon nitride (SiN). 
     The electrode pattern  230 , the N-type bonding pad  250  and the P-type bonding pad  240  may be made of a metal with superior electrical conductivity. 
     A method of fabricating a submount substrate for an LED chip having flip-chip type light emitting cells constructed as above-mentioned will be described below. 
     Concave portions and convex portions are formed on the substrate  200  to define the N-regions and the P-regions thereon. The widths, heights and shapes of the N-regions and P-regions may be modified variously depending on the sizes of the N-type metal bumpers  180  and P-type metal bumpers  170  of the LED chip  1000  to be bonded thereon. In this embodiment, the convex portions of the substrate  200  become the N-regions, and the concave portions of the substrate  200  become the P-regions. The substrate  200  with such a shape may be fabricated using a mold or through a predetermined etching process. That is, a mask for exposing the P-regions is formed on the substrate  200 , and exposed portions of the substrate  200  are then etched to form the recessed P-regions. Then, the mask is removed so that the recessed P-regions and the relatively protruding N-regions are formed. Alternatively, the recessed P-regions may be formed by means of machining. 
     Then, the dielectric film  210  is formed on the entire structure. At this time, the dielectric film  210  may not be formed in a case where the substrate  200  is not made of a conductive material. If a metal substrate with superior electrical conductivity is used to improve thermal conductivity, the dielectric film  210  is formed to function as a sufficient insulator. 
     The electrode patterns  230  each of which connects adjacent N-region and P-region in pair are formed on the dielectric film  210 . The electrode patterns  230  may be formed through a screen printing method, or the electrode patterns  230  may be formed by patterning through lithographic and etching techniques after an electrode layer is deposited. 
     The P-type metal bumpers  170  of the LED chip  1000  are bonded to the electrode patterns  230  on the P-regions, and the N-type metal bumpers  180  thereof are bonded to the electrode patterns  230  on the N-regions so that the LED chip  1000  and the submount substrate  200  are bonded together. At this time, the light emitting cells of the LED chip  1000  are coupled in series through the electrode patterns  230  to form an array of light emitting cells coupled in series. The P-type bonding pad  240  and N-type bonding pad  250  located at both the ends of the array of light emitting cells coupled in series may be connected through bonding wires, respectively. 
     The metal bumpers  170  and  180 , the electrode patterns  230 , and the bonding pads  240  and  250  can be bonded through various bonding methods, e.g., a eutectic method using the eutectic temperature. 
     At this time, the number of the light emitting cells coupled in series can be variously modified depending on an electric power source to be used and power consumption of the light emitting cells. 
     Referring to  FIG. 4 , the light emitting cells  100   a  to  100   c  are not arrayed on the substrate ( 110  in  FIG. 3 ) but are bonded to the submount  200  while being separated from one another, as compared with the light emitting cells of  FIG. 3 . Such light emitting cells may be formed by separating the substrate  110  from the LED chip  1000  using a laser or by removing the substrate  110  using a chemical mechanical polishing technique, after bonding the LED chip  1000  on the submount  2000 , as shown in  FIG. 4 . Alternatively, the light emitting cells  100   a ,  100   b , and  100   c  can be fabricated by partially separating the substrate  110  from each of the light emitting cells, as shown in  FIG. 34 . At this time, the N-type metal bumpers  170  and the P-type metal bumpers  180  of adjacent light emitting cells  100   a  to  100   c  are bonded to the electrode patterns  230  formed on the submount  2000  so that the light emitting cells can be electrically coupled in series. 
     In another exemplary embodiment of the present invention, as  FIG. 33  shows, the light emitting cells  100   a ,  100   b  and  100   c  may be fabricated by separating the substrate  110  from the plurality of light emitting cells in the light emitting cell block  1000  of  FIG. 3 . In this case, however, the light emitting cell block  1000  is formed without the buffer layer  120 . 
     Referring to  FIG. 5 , a flat substrate  200  with a plurality of N-regions and P-regions defined thereon is formed with electrode patterns  230  for connecting adjacent N-regions A and P-regions B, and an LED chip  1000  is then mounted on a submount  2000 . That is, contrary to  FIG. 3 , the electrode patterns  230  are formed on the submount substrate  200  on which certain patterns, e.g., concave and convex portions, are not formed, and the N-type metal bumpers  180  and the P-type metal bumpers  170  of adjacent light emitting cells of the LED chip  1000  are bonded on the electrode patterns  230  to electrically connect the light emitting cells to one another. At this time, it is preferred that the N-type metal bumpers  180  and the P-type metal bumpers  170  be formed such that top surfaces thereof are located in the substantially same plane. 
     In these embodiments, although it has been illustrated that the P-type and N-type metal bumpers  170  and  180  are formed on the light emitting cells within the LED chip  1000 , it is not limited thereto but the P-type and N-type metal bumpers  170  and  180  may be formed on the P-regions A and the N-regions B, respectively. At this time, certain metal electrodes (not shown) may be further formed on the N-type and P-type semiconductor layers  130  and  150  so as to be bonded to the metal bumpers  170  and  180 . 
       FIGS. 6 and 7  are circuit diagrams illustrating arrays of light emitting cells according to embodiments of the present invention. 
     Referring to  FIG. 6 , a first serial array  31  is formed by coupling light emitting cells  31   a ,  31   b  and  31   c  in series, and a second serial array  33  is formed by coupling other light emitting cells  33   a ,  33   b  and  33   c  in series. Here, the term “serial array” refers to an array of a plurality of light emitting cells coupled in series. 
     Both ends of each of the first and second serial arrays  31  and  33  are connected to an AC power source  35  and a ground, respectively. The first and second serial arrays are connected in reverse parallel between the AC power source  35  and the ground. That is, both ends of the first serial array are electrically connected to those of the second serial array, and the first and second serial arrays  31  and  33  are arranged such that their light emitting cells are driven by currents flowing in opposite directions. In other words, as shown in the figure, anodes and cathodes of the light emitting cells included in the first serial array  31  and anodes and cathodes of the light emitting cells included in the second array  33  are arranged in opposite directions. 
     Thus, if the AC power source  35  is in a positive phase, the light emitting cells included in the first serial array  31  are turned on to emit light, and the light emitting cells included in the second serial array  33  are turned off. On the contrary, if the AC power source  35  is in a negative phase, the light emitting cells included in the first serial array  31  are turned off, and the light emitting cells included in the second serial array  33  are turned on. 
     Consequently, the first and second serial arrays  31  and  33  are alternately turned on/off by the AC power source so that the light emitting chip including the first and second serial arrays can continue to emit light. 
     Although LED chips each of which comprises a single LED can be connected to one another to be driven by an AC power source as in the circuit of  FIG. 6 , space occupied by the LED chips are increased. However, in the LED chip of the present invention, a single chip can be driven by being connected to an AC power source, thereby preventing an increase in space occupied by the LED chip. 
     Meanwhile, although the circuit shown in  FIG. 6  is configured such that the both ends of each of the first and second serial arrays are connected to the AC power source  35  and the ground, respectively, the circuit may be configured such that the both ends thereof are connected to both terminals of the AC power source. Further, although each of the first and second serial arrays comprises three light emitting cells, this is only an illustrative example for better understanding and the number of light emitting cells may be increased, if necessary. The number of serial arrays may also be increased. 
     Referring to  FIG. 7 , a serial array  41  comprises light emitting cells  41   a ,  41   b ,  41   c,    41   e  and  41   f  Meanwhile, a bridge rectifier including diode cells D 1 , D 2 , D 3  and D 4  is arranged between an AC power source  45  and the serial array  41 , and between a ground and the serial array  41 . Although the diode cells D 1 , D 2 , D 3  and D 4  may have the same structure as the light emitting cells, they are not limited thereto but may not emit light. An anode terminal of the serial array  41  is connected to a node between the diode cells D 1  and D 2 , and a cathode terminal thereof is connected to a node between the diode cells D 3  and D 4 . Meanwhile, a terminal of the AC power source  45  is connected to a node between the diode cells D 1  and D 4 , and the ground is connected to a node between the diode cells D 2  and D 3 . 
     If the AC power source  45  is in a positive phase, the diode cells D 1  and D 3  of the bridge rectifier are turned on, and the diode cells D 2  and D 4  thereof are turned off. Therefore, current flows to the ground via the diode cell D 1  of the bridge rectifier, the serial array  41  and the diode cell D 3  thereof. 
     Meanwhile, if the AC power source  45  is in a negative phase, the diode cells D 1  and D 3  of the bridge rectifier are turned off, and the diode cells D 2  and D 4  thereof are turned on. Therefore, current flows to the AC power source via the diode cell D 2  of the bridge rectifier, the serial array  41  and the diode cell D 4  thereof. 
     Consequently, the bridge rectifier is connected to the serial array  41  so that the serial array  41  can be continuously driven using the AC power source  45 . Here, although the bridge rectifier is configured such that the terminals of the bridge rectifier are connected to the AC power source  45  and the ground, the bridge rectifier may be configured such that the both terminals are connected to both terminals of an AC power source. Meanwhile, as the serial array  41  is driven using the AC power source, a ripple may occur, and an RC filter (not shown) may be connected to prevent the occurrence of a ripple. 
     According to this embodiment, a single serial array may be driven by being electrically connected to an AC power source, and the light emitting cells can be effectively used as compared with the LED chip of  FIG. 6 . 
     LED packages or LED lamps with various structures may be provided by mounting an LED chip with the array of light emitting cells coupled in series or a submount having light emitting cells bonded thereto. LED packages or LED lamps with the array of light emitting cells coupled in series will be described in detail below. 
       FIGS. 8 to 10  are sectional views illustrating LED packages according to embodiments of the present invention. 
     Referring to  FIG. 8 , the LED package comprises a substrate  310 , electrodes  320  and  325  formed on the substrate  310 , a light emitting device  350  mounted on the substrate  310  and a molding member  370  encapsulating the light emitting device  350 . 
     The light emitting device  350  comprises an array of light emitting cells coupled in series through wires  80  as described with reference to  FIGS. 1 and 2 , or comprises a submount  2000  with the electrode patterns  250  and an array of light emitting cells coupled in series through the electrode patterns of the submount  2000  as described with reference to  FIGS. 3 to 5 . The light emitting device  350  comprises at least one array of light emitting cells, and may comprise at least two arrays of light emitting cells coupled in reverse parallel and/or an additional rectification bridge unit for a predetermined rectification operation. 
     Each of the light emitting cells comprises an N-type semiconductor layer and a P-type semiconductor layer, and the N-type semiconductor layer of one light emitting cell and the P-type semiconductor layer of another light emitting cell adjacent thereto are electrically connected to each other. Meanwhile, an N-type bonding pad and a P-type bonding pad may be formed to connect an external power source to one end and the other end of the array of light emitting cells coupled in series. In addition thereto, power source pads may be formed in the rectification bridge unit in a case where the light emitting device  350  includes the additional rectification bridge unit. 
     Since the light emitting cells are formed on a single substrate, it is possible to simplify a fabricating process and to reduce the size of a package as compared with a prior art in which respective light emitting diodes are mounted and then coupled in series. 
     The substrate  310  may be a printed circuit board with first and second lead electrodes  320  and  325  printed thereon. The lead electrodes  320  and  325  are electrically connected to the P-type bonding pad ( 90  in  FIGS. 1 and 2 , or  240  in  FIGS. 3 to 5 ) and the N-type bonding pad ( 95  in  FIGS. 1 and 2 , or  250  in  FIGS. 3 to 5 ), or the power source pads of the light emitting device  350 , respectively. 
     The lead electrodes  320  and  325  may be formed using a printing technique or attached to the substrate  310  using an adhesive. The first and second electrodes  320  and  325  may be made of a metallic material containing copper or aluminum with superior conductivity and formed such that they are electrically separated from each other. 
     The lead electrodes  320  and  325 , and the light emitting device  350  are electrically connected to one another through bonding wires  390 . That is, the first electrode  320  and one pad of the light emitting device  350  are connected through one bonding wire  390 , and the second electrode  325  and the other pad of the light emitting device  350  are connected through another bonding wire  390 . 
     The molding member  370  may be formed by curing a thermosetting resin, e.g., an epoxy or silicone resin. The molding member  370  may be formed in various forms such as a lens, a hexahedron, a flat plate, a hemisphere or a cylinder and further include a plurality of small lens features on the top surface thereof. 
     Meanwhile, the LED package may further comprise a predetermined phosphor (not shown) for realizing light of a target color over the light emitting device  350 . The phosphor may be applied on the light emitting device  350 . Further, after the phosphor and the thermosetting resin are mixed together, the molding member  370  is formed using the mixture so that the phosphor can be dispersed in the molding member  370 . 
     The LED package according to this embodiment may further comprise a reflective portion.  FIGS. 9 and 10  show LED packages with such a reflective portion. 
     Referring to  FIG. 9 , the light emitting device  350  is mounted within a reflective portion  340 . The reflective portion  340  may be formed by mechanically processing the substrate ( 310  in  FIG. 8 ) to form a predetermined groove. An inner wall of the groove is formed to have a certain slope. As a result, light emitted from the light emitting device  350  and then incident on the reflective portion  340  is reflected from the reflective portion  340  to the outside so that luminance of the light can be improved. It is preferred that a bottom surface of the groove is in the form of a plane to mount the light emitting device  350  thereon. 
     Referring to  FIG. 10 , a reflective portion  360  is formed on a flat substrate  310  to surround a light emitting device  350 . The reflective portion  360  has a certain slope to reflect light, which is incident from the light emitting device  350 , to the outside. The reflective portion  360  may be formed by molding a thermoplastic or thermosetting resin. Meanwhile, a molding member  370  encapsulates the light emitting device  350  by filling the inside of the reflective portion  360 . 
     Further, the reflective portion  360  and the substrate  310  may be formed integrally with each other. At this time, lead electrodes  320  and  325  are formed using a lead frame, and the reflective portion  360  and the substrate  310  are formed by insert-molding the lead frame. 
     The LED packages according to embodiments of the present invention may comprise one or more light emitting devices  350  as described above.  FIG. 11  is a sectional view illustrating an LED package having a plurality of light emitting devices  350 . 
     Referring to  FIG. 11 , the LED package according to this embodiment comprises a substrate  310 , lead electrodes  320  and  325  formed on the substrate  310 , and a plurality of light emitting devices  350  mounted on the substrate  310 . To enhance luminance of light, a reflective portion  360  is formed to surround the light emitting devices  350 , and a molding member  370  encapsulating the light emitting devices  350  is formed over the light emitting devices  350 . Further, the lead electrodes  320  and  325  are formed on the substrate  310  and connected to the plurality of light emitting devices  350  through bonding wires  390 . Accordingly, the plurality of light emitting devices  350  can be connected to an external power source through the lead electrodes  320  and  325  and the bonding wires  390 . 
     As described with reference to  FIG. 8 , each of the light emitting devices  350  comprises an array of light emitting cells coupled in series. 
     According to this embodiment, the plurality of light emitting devices  350  are variously mounted in series, parallel or series-parallel on the substrate  310  to obtain desired luminous power, and high luminous power can be obtained by mounting the plurality of light emitting devices  350 . 
       FIGS. 12 and 13  are sectional views illustrating LED packages each of which employs a heat sink according to some embodiments of the present invention. 
     Referring to  FIG. 12 , the LED package according to this embodiment comprises a substrate or housing  311 , which is formed with lead electrodes  320  and  325  at both sides thereof and also has a through-hole, a heat sink  313  mounted inside the through-hole of the housing  311 , a light emitting device  350  mounted on the heat sink  313 , and a molding member  370  encapsulating the light emitting device  350 . 
     The heat sink  313  mounted inside the through-hole of the housing  311  is made of a material with superior thermal conductivity and dissipates heat generated from the light emitting device  350  to the outside. As shown in  FIG. 13 , the heat sink  313  may have a recessed region of an inverted frusto-conial shape in a predetermined region of the center thereof. The recessed region constitutes a reflective portion  380 , and the light emitting device  350  is mounted on a bottom surface of the recessed region. To enhance luminance and light-focusing performance, the recessed region of the inverted frusto-conial shape is formed to have a certain slope. 
     As described with reference to  FIG. 8 , the light emitting device  350  comprises an array of light emitting cells coupled in series. The light emitting device  350  is connected to the lead electrodes  320  and  325  through bonding wires  390 . Further, in these embodiments, a plurality of light emitting devices  350  may be mounted on the heat sink  313 . 
     As described with reference to  FIG. 8 , the molding member  370  encapsulating the light emitting device  350  may be formed in various shapes. Further, a phosphor (not shown) is formed over the light emitting device  350  to emit light of a target color. 
       FIGS. 14 to 17  are views illustrating LED packages each of which employs a heat sink according to other embodiments of the present invention.  FIGS. 14 and 15  are perspective and plan views illustrating an LED package  410  according to an embodiment of the present invention, respectively, and  FIG. 16  is a plan view illustrating lead frames  415  and  416  used in the LED package  410 . Meanwhile,  FIG. 17  is a sectional view illustrating the LED package. 
     Referring to  FIGS. 14 to 17 , the LED package  410  comprises a pair of lead frames  415  and  416 , a heat sink  413  and a package body  411  supporting the lead frames and the heat sink. 
     As shown in  FIG. 17 , the heat sink  413  may have a base and a protrusion protruding upwardly from a central portion of the base. Although the base and the protrusion can have cylindrical shapes as shown in the figure, they are not limited thereto but may have various forms such as a polygonal post and combinations thereof. Meanwhile, an external appearance of the package body  411  may be modified depending on the shape of the base of the heat sink  413 . For example, in a case where the base is in the form of a cylinder, the external appearance of the package body  411  may be a cylinder as shown in the figure. Alternatively, in a case where the base is in the form of a rectangular post, the external appearance of the package body  411  may be a rectangular post. 
     The heat sink  413  has a lead frame-receiving groove  413   a  for receiving the lead frame  415  at a side surface of the protrusion. Although the receiving groove  413   a  can be formed at a portion of the side surface of the protrusion, it may be preferably formed as a continuous groove along the side surface of the protrusion. Accordingly, it is easy to combine the lead frame  415  into the continuous receiving groove  413   a  regardless of rotation of the heat sink  413 . 
     Meanwhile, the heat sink  413  may have a latching groove at a side surface  413   b  of the base. The latching groove may be formed at a portion of the side surface  413   b  of the base, or it may be continuous along the surface thereof. Since heat dissipation is promoted as a bottom surface of the heat sink  413  becomes broader, a lower end portion of the side surface of the base may be exposed to the outside as shown in  FIGS. 14 and 17 . However, the latching groove and a portion of the side surface of the base above the latching groove are covered with the package body  411 . Thus, the latching groove receives a portion of the package body  411 , so that the heat sink  413  can be prevented from being separated from the package body  411 . 
     The heat sink  413  is made of a conductive material, particularly, a metal such as copper (Cu) or aluminum (Al), or an alloy thereof. Further, the heat sink  413  may be formed using a molding or pressing technique. 
     The pair of lead frames  415  and  416  are located around the heat sink  413  while being spaced apart from each other. The lead frames  415  and  416  have inner lead frames  415   a  and  416   a , and outer lead terminals  415   b  and  416   b , respectively. The inner lead frames  415   a  and  416   a  are located inside the package body  411 , and the outer lead frames  415   b  and  416   b  extend from the inner lead frames and protrude toward the outside of the package body  411 . At this time, the outer lead frames  415   b  and  416   b  may be bent for surface mounting. 
     Meanwhile, the inner lead frame  415   a  is combined into the receiving groove  413   a  of the heat sink  413  and then electrically connected directly to the heat sink. As shown in  FIG. 16 , the inner lead frame  415   a  may take the shape of a ring of which a portion is removed to be received in the receiving groove  413   a  of the heat sink  413 . As the portion removed from the ring-shaped inner lead frame becomes smaller, a contact surface between the heat sink  413  and the inner lead frame  415   a  more increases to reinforce electrical connection. At this time, the inner lead frame  415   a  may take various shapes such as a circular ring or a polygonal ring depending on the shape of the protrusion of the heat sink  413 . 
     On the other hand, the inner lead frame  416   a  is located while being spaced apart from the heat sink  413 . The inner lead frame  416   a  is located at the removed portion of the inner lead frame  415   a  so that it can be located close to the heat sink  413 . The lead frame  416  may have a fastening groove  416   c , and the fastening groove  416   c  receives a portion of the package body  411  so that the lead frame  416  can be prevented from being separated from the package body  411 . The lead frame  415  may also have a fastening groove. 
     The package body  411  supports the heat sink  413  and the lead frames  415  and  416 . The package body  411  may be formed using an insert-molding technique. That is, the package body  411  may be formed by combining the lead frame  415  into the receiving groove of the heat sink  413 , positioning the lead frame  416  at a corresponding position, and insert-molding a thermoplastic or thermosetting resin. Using the insert-molding technique, the package body  411  of such a complicated structure can be easily formed. At this time, the protrusion of the heat sink  413  may protrude upwardly beyond the top of the package body  411 . 
     Meanwhile, the package body  411  has an opening for exposing portions of the respective inner lead frames  415   a  and  416   a , and a portion of the protrusion of the heat sink  413 . Thus, a groove is formed between the protrusion of the heat sink  413  and the package body  411 . As shown in  FIGS. 14 and 15 , although the groove may be a continuous groove along the periphery of the protrusion, it is not limited thereto but may be intermittent. 
     Further, the package body  411  may further comprise an encapsulant receiving groove  411   a  located along the outer periphery thereof. The encapsulant receiving groove  411   a  receives a molding member or encapsulant  421  so that the encapsulant  421  is prevented from being separated from the package body  411 . In addition thereto, a marker  411   b  for indicating the positions of the lead frames  415  and  416  may be formed at the package body as shown in  FIGS. 14 and 15 . The marker  411   b  indicates the position of the lead frame  415  directly connected to the heat sink  413  and the position of the lead frame  416  spaced apart from the heat sink. 
     Since the package body  411  is formed using the insert-molding technique, it fills the latching groove formed at the side surface  413   b  of the base of the heat sink  413 , thereby supporting the heat sink. In addition thereto, the lead frame  415  is received in the receiving groove  413   a  of the heat sink, and the lead frame is also supported by the package body. Further, the package body fills the remainder of the receiving groove  413   a  except the portion thereof contacted with the lead frame. Thus, according to the embodiments of the present invention, the heat sink is prevented from being separated from the package body. 
     Referring again to  FIG. 17 , a light emitting device  417  is mounted on the heat sink  413 . The light emitting device  417  comprises an array of light emitting cells coupled in series through bonding wires  80  as described with reference to  FIGS. 1 and 2 , or comprises a submount  2000  with electrode patterns  250  and an array of light emitting cells coupled in series through the electrode patterns  250  of the submount  2000 . The light emitting device  417  may comprise at least one array of light emitting cells, and may comprise at least two arrays of light emitting cells connected in reverse parallel and/or an additional rectification bridge unit for a predetermined rectification operation. 
     The light emitting device  417  is electrically connected to the lead frames  415  and  416  through bonding wires  419   a  and  419   b . For example, in a case where the light emitting device  417  is an LED chip described with reference to  FIG. 1 or 2 , the bonding wires  419   a  and  419   b  connect the bonding pads ( 90  and  95  of  FIG. 1 or 2 ) formed at both ends of the array of light emitting cells coupled in series to the lead frames  415  and  416 . 
     Further, in a case where the light emitting device  417  comprises the submount  2000  and the light emitting cells  100  bonded on the submount as described with reference to  FIGS. 3 to 5 , the bonding wires  419   a  and  419   b  connect the bonding pads  240  and  250  formed on the submount to the lead frames  415  and  416 . If the LED chip  1000  is bonded to the submount  2000  as shown in  FIG. 3 or 5 , the submount  2000  is interposed between the LED chip  1000  and the heat sink  413 . 
     The bonding wire  419   b  may be connected directly to the lead frame  415  or the heat sink  413 . 
     Meanwhile, the encapsulant  421  covers the top of the LED chip  417 . The encapsulant  421  may be an epoxy or silicone resin. Further, the encapsulant may contain a phosphor  421   a  for converting the wavelength of light emitted from the LED chip  417 . For example, in a case where the LED chip  417  emits blue light, the encapsulant  421  may contain the phosphor  421   a  for converting the blue light into yellow light, or green and red light. As a result, white light is emitted from the LED package to the outside. 
     The encapsulant  421  fills the opening of the package body  411  and the encapsulant receiving groove  411   a . Therefore, the bonding force of the encapsulant  421  with the package body  411  increases so that the encapsulant is prevented from being separated from the LED package. Meanwhile, the encapsulant  421  may be a lens and take the shape of a convex lens such that light emitted from the LED chip  417  emerges in a predetermined range of directional angles as shown in  FIG. 17 . Otherwise, the encapsulant may have various shapes depending on the object of use thereof. 
       FIG. 18  is a sectional view illustrating an LED package employing a heat sink according to a further embodiment of the present invention. 
     Referring to  FIG. 18 , the LED package according to this embodiment comprises a pair of lead frames  415  and  416 , a heat sink  413  and a package body  411 . Further, as described with reference to  FIG. 17 , a light emitting device  417  is mounted on the heat sink  413 , bonding wires  419   a  and  419   b  connect the light emitting device  417  to the lead frames  415  and  416 , and an encapsulant  421  covers the top of the LED chip  417 . A phosphor  421   a  may be contained within the encapsulant  421 . Features thereof different from the LED package of  FIG. 17  will be described below. 
     In the LED package according to this embodiment, the heat sink  413  and the lead frame  415  are formed integrally with each other. That is, the lead frame  415  is made of the same material as the heat sink  413 , and formed together with the heat sink  413 . Since the heat sink  413  and the lead frame  415  are formed integrally with each other, the receiving groove ( 413   a  of  FIG. 17 ) for the lead frame can be eliminated. 
     According to this embodiment, since the heat sink  413  and the lead frame  415  are formed integrally with each other, the heat sink  413  can be more prevented from being separated from the package body  411 . 
       FIGS. 19 to 23  are views illustrating LED packages each of which employs a heat sink according to further embodiments of the present invention. Here,  FIGS. 19 and 20  are upper and lower perspective views illustrating an LED package according to an embodiment of the present invention, and  FIG. 21  is an exploded perspective view illustrating the LED package. Meanwhile,  FIG. 22  is a sectional view showing that an LED chip is mounted on the LED package of  FIGS. 19 and 20  and connected thereto through bonding wires, and  FIG. 23  is a sectional view showing that a molding member is formed on an LED package of  FIG. 22  and a lens is mounted thereon. 
     Referring to  FIGS. 19 to 21 , the LED package of the present invention comprises a package body including a first package body  506  and a second package body  509 . Although the first package body and the second package body may be separately fabricated, they may be formed integrally with each other using an insert-molding technique. If they are formed integrally with each other, they are not separated into the first package body  506  and the second package body  509 . For the sake of convenience of description, however, they are shown in a separated state. 
     The first package body  506  has an opening  508  and is formed at an upper face thereof with a groove that is recessed to receive an encapsulant or a molding member and surrounded by an inner surface thereof. Although the opening  508  has the same area as the recessed portion, it may have an area smaller than that of the recessed portion as shown in the figure. A stepped portion  507  may be formed in the inner wall of the first package body to receive the molding member that will be described later. The second package body  509  has a through-hole  511  exposed through the opening of the first package body  506 . Further, inner frame-receiving grooves  510  are formed in an upper face of the second package body  509 , and a heat sink-seating groove  512  is formed in a lower face thereof. The inner frame-receiving grooves  510  are located around the through-hole  511  while being spaced apart therefrom. 
     A pair of lead frames  501  are located between the first package body  506  and the second package body  507  while being spaced apart from each other. The lead frames  501  have a pair of inner frames  503  exposed through the opening of the first package body  506 , and outer frames  503  extending from the inner frames and protruding to the outside of the package body. The inner frames  503  are arranged to form a symmetric structure so that a hollow portion  505  can be defined at a central position therebetween. The inner frames  503  are seated inside the inner frame-receiving grooves  510  such that the through-hole  511  is located inside the hollow portion  505 . 
     Meanwhile, each of the inner frames  503  may have supports  504  extending therefrom. The supports  504  function to support the lead frames  501  when a lead panel (not shown) having a plurality of lead frames  501  connected thereto is used for mass-production of LED packages. Further, as shown in  FIGS. 19 and 20 , the outer frames  502  may be bent such that the LED package can be mounted on the surface of a printed circuit board or the like. 
     Meanwhile, the lead frames  501  can form a symmetric structure as shown in the figure but is not limited thereto. Moreover, although the hollow portion  505  surrounded by the inner frames may have a hexagonal shape, it is not limited thereto but may have various shapes such as a circle, a rectangle and the like. 
     The heat sink  513  is combined with the second package body  509  on the lower face of the second package body  509 . The heat sink  513  has a base  514  seated in the heat sink-seating groove  512  of the second package body, and a protrusion  515  to be combined with the second package body while protruding at a central portion of the base and to be inserted into the through-hole  511  of the second package body. A latching step may be formed on a side surface of the protrusion  515 . An upper surface  516  of the protrusion  515  may be recessed and exposed through the opening  508  of the first package body  506 . 
     Meanwhile, the first and second package bodies  506  and  509  can be made of materials such as thermal conductive plastics or high thermal conductive ceramics. The thermal conductive plastics include acrylonitrile butadiene styrene (ABS), liquid crystalline polymer (LCP), polyamide (PA), polyphenylene sulfide (PPS), thermoplastic elastomer (TPE) and the like. The high thermal conductive ceramics include alumina (Al 2 O 3 ), silicon carbide (SiC), aluminum nitride (AlN) and the like. Among the ceramics, aluminum nitride (AlN) has properties equivalent to those of alumina and is superior to alumina in view of thermal conductivity. Thus, aluminum nitride has been widely used in practice. 
     If the first and second package bodies  506  and  509  are made of thermal conductive plastics, they may be formed using an insert-molding technique after the lead frames  501  are located therebetween. 
     On the other hand, if the first and second package bodies  506  and  509  are made of the high thermal conductive ceramics, the first package body  506  and the second package body  509  may be separately formed and then fixedly attached thereto using an adhesive with strong adhesive force or the like. 
     Referring to  FIG. 22 , in the LED package according to the present invention, two stepped portions  507  are formed in the inner wall of the first package body  506 , so that they can serve as fixing steps for use in molding the molding member or in mounting a lens, which will be described later. 
     Meanwhile, a latching step  515   a  of the heat sink  513  is formed at an side surface of the protrusion  515  so that it can be fixedly inserted into a groove formed in a wall defining the through-hole  515  of the second package body  509 . Further, the latching step  515   a  may be formed at an upper portion of the protrusion  515  to be coupled to the upper face of the second package body  509 . Accordingly, the heat sink  513  can be prevented from being separated from the package body. The latching step may be formed on a side surface of the base. 
     The heat sink  513  is made of a thermally conductive material, particularly, a metal such as copper (Cu) or aluminum (Al), or an alloy thereof. Further, the heat sink  513  may be formed using a molding or pressing technique. 
     The light emitting device  517  is mounted on the upper surface  516  of the heat sink  513 . Since the light emitting device  517  is the same as the light emitting device  417  described with reference to  FIG. 17 , a description thereof will be omitted. 
     Referring to  FIG. 23 , molding members  521  and  523  encapsulate the top of the light emitting device  517  and are molded inside the groove of the first package body  506 . The molding member can comprise the first molding member  521  and the second molding member  523 . Each of the first and second molding members may be made of an epoxy or silicone resin, and they may be made of the same material or different materials. It is preferred that the second molding member  523  have a value of hardness larger than that of the first molding member  521 . The first and second molding members can fill the groove of the first package body  506  to form an interface in the vicinity of the stepped portions  507   a.    
     Meanwhile, a phosphor may be contained in the first molding member  521  and/or the second molding member  523 . Further, a diffuser for diffusing light may be contained in the first molding member  521  and/or the second molding member  523 . The phosphor is applied on the light emitting device  517  so that it may be disposed between the first molding member  521  and the light emitting device  517 , or on the first molding member  521  or the second molding member  523 . 
     Further, a lens  525  may be disposed on the top of the molding member. The lens  525  is fixed to an upper one of the stepped portions  507   b . The lens  525  take the shape of a convex lens such that light emitted from the LED chip  517  emerges in a predetermined range of directional angles as shown in the figure. Otherwise, the lens may have various shapes depending on the object of use thereof. 
       FIG. 24  is a sectional view illustrating an LED lamp having light emitting cells coupled in series according to an embodiment of the present invention. 
     Referring to  FIG. 24 , the LED lamp comprises a top portion  603 , and a first lead with a pin-type leg  601   a  extending from the top portion  603 . A second lead with a pin-type leg  601   b  is arranged to correspond to the first lead while being spaced apart from the first lead. 
     The light emitting device  617  is mounted on the top portion  603  of the first lead. The top portion  603  of the first lead may have a recessed cavity, and the light emitting device  617  is mounted inside the cavity. A sidewall of the cavity may form an inclined reflective surface such that light emitted from the light emitting device  617  can be reflected in a predetermined direction. The light emitting device  617  is electrically connected to the first and second leads through bonding wires  613   a  and  613   b.    
     Since the light emitting device  617  is the same as the light emitting device  417  described with reference to  FIG. 17 , a description thereof will be omitted. 
     Meanwhile, a molding member  611  encapsulates the top portion  603  of the first lead, the light emitting device  617 , and a portion of the second lead. The molding member  611  is generally formed of a transparent resin. The molding member  611  may protect the light emitting device  617  and simultaneously have a lens function of refracting light, which has been emitted from the LED chip  617 , in a range of predetermined directional angles. 
     In addition thereto, an encapsulant  609  is formed inside the cavity to cover the top of the light emitting device  617 . The encapsulant  609  may be made of an epoxy or silicone resin. 
     Meanwhile, the encapsulant  609  may contain a phosphor. The phosphor converts the wavelength of light emitted from the light emitting device  617  so that light with a desired wavelength can be emitted. The phosphor may be formed by being applied on the light emitting device  617 . 
     The pin-type legs  601   a  and  601   b  are inserted through and mounted on a printed circuit board (PCB) (not shown), and a current is applied to the LED lamp through the PCB so that the light emitting device  617  can emit light. Meanwhile, the pin-type legs  601   a  and  601   b  may be directly connected to a socket of a household AC power source. Thus, the LED lamp can be used for general illumination at home. 
     Next, high flux LED lamps, which are a kind of LED lamp, according to other embodiments of the present invention will be described with reference to  FIGS. 25 to 32 . 
       FIGS. 25 and 26  are perspective views illustrating high flux LED lamps according to other embodiments of the present invention, and  FIG. 27  is a sectional view of  FIG. 26 . 
     Referring to  FIGS. 25 to 27 , the high flux light emitting diode (LED) lamp has a first lead and a second lead. The first lead has a top portion  703 . Two pin-type legs  701   a  and  701   c  extend from the top portion  703  and are exposed to the outside. The second lead has two pin-type legs  701   b  and  701   d  corresponding to the first lead, and the two pin-type legs  701   b  and  701   d  are connected to each other at upper portions thereof. The first and second leads may be made of a metal such as copper or iron, or an alloy thereof, and they may be formed using a molding technique. 
     The top portion  703  of the first lead has an upper surface oil which a light emitting device  717  is to be mounted, and a lower surface. The upper surface of the top portion  703  may be a flat surface. Further, as shown in  FIG. 27 , a cavity may be formed in the upper surface of the top portion  703 , and the light emitting device  717  is mounted inside the cavity. A sidewall of the cavity may form an inclined reflective surface such that light emitted from the LED can be reflected in a predetermined direction. 
     Since the light emitting device  717  is the same as the light emitting device  417  described with reference to  FIG. 17 , a description thereof will be omitted. The light emitting device  717  is electrically connected to the first and second leads through bonding wires  713   a  and  713   b.    
     Meanwhile, molding member  711  encapsulates the top portion  703  of the first lead, the light emitting device  717  and a portion of the second lead. Although the molding member  711  may be formed of a transparent resin such as an epoxy or silicone resin, it may be formed of a translucent resin depending on the object thereof. The molding member  711  may protect the light emitting device  717  and simultaneously have a lens function of refracting light, which has been emitted from the LED chip  717 , in a predetermined range of directional angles. Thus, an external appearance of the molding member  711  may take various shapes depending on a desired directional angle. For example, an upper portion of the molding member  711  may be convex with a smaller curvature to obtain a narrow range of directional angles, whereas the upper portion of the molding member  711  may be substantially flat with a larger curvature to obtain a wide range of directional angles. Further, as shown in  FIG. 25 , the molding member  711  may be formed such that a lens  711   a  is defined in the vicinity of the upper portion of the light emitting device  717 . Alternatively, as shown in  FIG. 26 , the molding member  711  may be formed such that the entire upper portion thereof takes the shape of a lens. 
     In addition thereto, an encapsulant  709  may be formed inside the cavity to cover the top of the light emitting device  717 . The encapsulant  709  may be made of an epoxy or silicone resin. Meanwhile, the encapsulant  709  may contain a phosphor as described with reference to  FIG. 24 . 
     The pin-type legs  701   a ,  701   b ,  701   c  and  701   d  are inserted through and mounted on a printed circuit board (PCB) (not shown), and may be then fixed by means of soldering. A current is applied to the LED lamp through the PCB so that the light emitting device can emit light. 
       FIG. 28  is a perspective view illustrating a high flux LED lamp according to a further embodiment of the present invention, and  FIGS. 29 and 30  are sectional and side views of  FIG. 28 , respectively. 
     Referring to  FIGS. 28 to 30 , the LED lamp comprises a top portion  723  and a first lead with a snap-type leg  721   a  extending from the top portion  723 . The snap-type leg  721   a  has a wide side surface and a bent portion  722   a  that is bent substantially perpendicularly at a lower portion thereof. Further, a second lead with a snap-type leg  721   b  is arranged to correspond to the first lead while being spaced apart therefrom. The snap type leg  721   b  of the second lead also has a wide side surface and a bent portion  722   b  that is bent substantially perpendicularly at a lower portion thereof. It is preferred that the bent portions  722   a  and  722   b  extend in opposite directions. The first and second leads may be made of a metal such as copper or iron, or an alloy thereof, and they may be formed using a molding technique. 
     As described with reference to  FIG. 27 , the top portion  723  of the first lead has an upper surface on which a light emitting device  717  is to be mounted and a lower surface. The upper surface of the top portion  723  may be a flat surface. Alternatively, as shown in  FIG. 29 , a cavity may be formed in the upper surface of the top portion  723 , and the light emitting device  717  is mounted inside the cavity. A sidewall of the cavity may form an inclined reflective surface such that light emitted from the LED can be reflected in a predetermined direction. 
     As described with reference to  FIG. 27 , the light emitting device  717  is electrically connected to the first and second leads through bonding wires  713   a  and  713   b . Thus, after the bent portions  722   a  and  722   b  of the first and second leads are fixed to the PCB, a current is applied to the LED lamp through the PCB. 
     Meanwhile, as described above, the molding member  711  encapsulates the top portion  723  of the first lead, the light emitting device  717  and a portion of the second lead, and an encapsulant  709  can cover the light emitting device  717  inside the cavity. Further, the encapsulant  709  may contain a phosphor. 
     Meanwhile, a heat sink  723   a  may extend from the top portion  723  of the first lead in a direction parallel with the leg  721   a  of the first lead. The heat sink  723   a  protrudes at least outside the molding member  711 . The heat sink  723   a  may extend to the lowermost portion of the leg  721   a  of the first lead. Accordingly, in a case where the LED lamp is mounted on the PCB, the heat sink  723   a  may also be attached to the PCB. The heat sink  723   a  may have grooves on the surface thereof. The grooves increase the surface area of the heat sink  723   a . Such grooves may be formed to have various shapes and widths. The heat sink  723   a  may be formed integrally with the top portion  723  and leg  721   a  of the first lead. 
     According to the embodiments of the present invention, the LED chip  717  emits light by means of the current applied thereto and also generates heat at this time. The heat generated from the LED chip  717  is dissipated to the outside via the top portion  723  and leg  721   a  of the first lead, the second lead and the wires  713   a  and  713   b . Since the legs  721   a  and  721   b  of the first and second leads are of a snap type, the surface area thereof is broader than those of the pin-type legs. Thus, the heat dissipation performance of the LED lamp is enhanced. In addition thereto, in a case where the heat sink  723   a  extends from the top portion  723  of the first lead, heat can be dissipated through the heat sink  723   a , so that the heat dissipation performance of the LED lamp can be more enhanced. The heat sink  723   a  may extend from the top portion  703  of the high flux LED lamp with the pin-type legs  701   a  to  701   d  described with reference to  FIGS. 25 to 27 . 
       FIGS. 31 and 32  are side views illustrating high flux LED lamps in which heat dissipation performance is enhanced by modifying the snap-type legs  721   a  and  721   b.    
     Referring to  FIG. 31 , although the LED lamp has the same components as the LED lamp described with reference to  FIGS. 28 to 30 , it has a snap-type leg  751   a  of a first lead and/or a snap-type leg (not shown) of a second lead, which are modified from the snap-type legs  721   a  and  721   b  of the first lead and/or the second lead. That is, the leg  751   a  of the first lead has at least one through-hole  751   h  through which air can pass. Further, the leg of the second lead may also have at least one through-hole through which air can pass. The through-holes  751   h  may be formed to take various shapes such as a rectangle, a circle, and an ellipse. Moreover, the through-holes  751   h  may be arranged in various patterns within the leg  751   a  of the first lead. That is, as shown in  FIG. 31 , the through-holes may be arranged in rows, in columns, or in a matrix. The through-holes  751   h  may also be arranged within the leg of the second lead. 
     According to this embodiment, since air can pass through the through-holes  751   h , the legs of the leads can be cooled by means of convection. Thus, the heat dissipation performance of the LED lamp can be more enhanced. 
     Referring to  FIG. 32 , although the LED lamp according to this embodiment has the same components as the LED lamp described with reference to  FIGS. 28 to 30 , it has a snap-type leg  771   a  of a first lead and/or a snap-type leg (not shown) of a second lead, which are modified from the snap-type legs  721   a  and  721   b  of the first lead and/or the second lead. That is, the leg  771   a  of the first lead has grooves  771   g . The grooves  771   g  may be formed on an outer surface and/or an inner surface of the leg  771   a  of the first lead. Further, the grooves  771   g  may be formed on the leg of the second lead. The grooves  771   g  may be formed to take various shapes such as a line and a spiral. 
     According to this embodiment, the surface area of the leg of the first lead and/or that of the second lead can be increased, thereby more enhancing heat dissipation performance through the leg of the first lead and/or the leg of the second lead. 
     Although some exemplary embodiments have been described herein, it should be understood that the present invention is not limited to certain embodiments. In addition, some features of a certain embodiment may also be applied to other embodiments in the same or similar ways without departing from the spirit and scope of the present invention as set forth in the claims.