Abstract:
A light emitting device includes a package body, a light emitting diode, a transparent resin material, and a wire. The package body includes a bottom part and a side part. The bottom part includes a first electrode and a second electrode electrically connecting the upper surface and the bottom surface of the bottom part, respectively. The side part includes an upper surface including a trench and a bottom surface being in contact with the upper surface of the bottom part, wherein the upper surface of the bottom part is lower than the upper surface of the side part such that the package body includes a cavity surrounded by the side part, and the bottom surface of the bottom part includes a second opened portion that divides the first electrode and the second electrode, and wherein a portion of the transparent resin material is disposed inside of the trench.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuous application of Ser. No. 12/436,522 filed on May 6, 2009, and claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2008-0042236, filed on May 7, 2008, which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    Embodiments relate to a semiconductor light emitting device. 
         [0003]    Light Emitting Diodes (LEDs) use GaAs, GaN, InGaN and InGaAlP-based compound semiconductor materials to constitute a light emitting source, thereby realizing various colors. 
         [0004]    Characteristics of the LEDs are determined depending on materials, colors, brightness and brightness intensity of the compound semiconductor materials. In addition, the LEDs are fabricated in the form of package and are applied to various fields of a lightening indicator, a character displayer and an image displayer. 
       SUMMARY 
       [0005]    Embodiments provide a light emitting device comprising a package body comprising a trench around a light emitting diode. 
         [0006]    Embodiments provide a light emitting device in which a cavity and a trench are defined on/around a package body to prevent a resin from overflowing. 
         [0007]    An embodiment provides a light emitting device comprising: a package body including a bottom part having a first electrode and a second electrode, a side part having a trench, and a cavity, a light emitting diode disposed on the first electrode, a transparent resin material disposed inside of the cavity, and a wire connecting the light emitting diode to at least one of the first electrode and the second electrode, wherein the bottom part having an upper surface and a bottom surface, wherein the bottom part includes a first electrode and a second electrode electrically connecting the upper surface and the bottom surface of the bottom part, respectively, wherein a side part has an upper surface including the trench and a bottom surface being in contact with the upper surface of the bottom part, wherein the upper surface of the bottom part is lower than the upper surface of the side part such that the package body includes a cavity surrounded by the side part, wherein the upper surface of the bottom part includes a first opened portion that divides the first electrode and the second electrode, and the bottom surface of the bottom part includes a second opened portion that divides the first electrode and the second electrode, and wherein a portion of the transparent resin material is disposed inside of the trench. 
         [0008]    The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a side-sectional view of a light emitting device according to a first embodiment. 
           [0010]      FIG. 2  is a plan view illustrating a trench of a package body of  FIG. 1 . 
           [0011]      FIG. 3  is a side-sectional view of  FIG. 2 . 
           [0012]      FIG. 4  is a plan view of a light emitting device according to a second embodiment. 
           [0013]      FIG. 5  is a plan view of a light emitting device according to a third embodiment. 
           [0014]      FIG. 6  is a perspective view of a light emitting device according to a fourth embodiment. 
           [0015]      FIG. 7  is a side-sectional view of a light emitting device according to a fifth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0016]    Hereinafter, a light emitting device according to embodiments will be described with reference to the accompanying drawings. 
         [0017]      FIG. 1  is a side-sectional view of a light emitting device according to a first embodiment,  FIG. 2  is a plan view illustrating a trench of a package body of  FIG. 1 , and  FIG. 3  is a side-sectional view of  FIG. 2 . 
         [0018]    Referring to  FIGS. 1 to 3 , a light emitting device  100  comprises a package body  110  having a cavity  101  and a trench  130 , electrodes  112  and  114 , a light emitting diode  120 , a resin material  140 , and a lens  150 . The light emitting device  100  may be defined as a light emitting diode package. This term may be variously defined within the technical scope of embodiments. 
         [0019]    For example, the package body  110  may be formed of a material having a high insulating property or a high thermal conductivity such as silicon, silicon carbide (SiC), and aluminum nitride (AlN). Hereinafter, for convenience of description, the package body  110  will refer to as a silicon-based wafer level package (WLP). 
         [0020]    The package body  110  may comprise a frame having a polyhedral shape. The package body  110  may have the same length as each other or lengths different from each other in horizontal and vertical length, but it is not limited thereto. 
         [0021]    The cavity  101  is defined in an inner upper portion of the package body  110 . A predetermined etching process, e.g., a wet etching process and/or a dry etching process may be performed on the package body  110  to form the cavity  101  having a vessel (or a bathtub) shape or a depressed structure. 
         [0022]    A lateral surface  117  of the cavity  101  may be perpendicular to a bottom surface of the cavity  101  or inclined outwardly with respect to a vertical shaft. 
         [0023]    The cavity  101  of the package body  110  may have a single layer or a multi-layer structure. In case of the cavity  101  having the multi-layer structure, at least one cavity may be further defined in a portion of the bottom surface of the cavity  101 . 
         [0024]    Referring to  FIGS. 2 and 3 , the trench  130  is defined around a top surface of the package body  110 . The trench  130  is disposed along an outer circumference of the cavity  101  by a predetermined depth. The trench  130  may have a shape different from an outer shape of the cavity  101 , e.g., a circular or an oval shape. 
         [0025]    Referring to  FIG. 3 , the trench  130  may have a depth less than about 30 um from a top surface  103  of the package body  110 . The depth of the trench  130  may be defined by considering prevention of resin overflow and electrode formation. 
         [0026]    The dry etching process and/or the wet etching process may be performed to form the trench  130 . In detail, in the dry etching process, a mask layer may be formed on a surface of the package body  11 , and then, the mask layer may be patterned to form a mask pattern having a desired shape using exposing, developing, and etching processes of photolithography processes. An open region having a trench shape is formed using the mask pattern, and then, the dry etching process is performed. Reactive ion etching (RIE), magnetically enhanced reactive ion etching (MERIE), inductively coupled plasma (ICP) processes using plasma may be selectively performed in the dry etching process. The dry etching process may be performed on the package body  110  to form the trench  130  having the predetermined depth (e.g., less than about 30 um). 
         [0027]    In the wet etching process, when the mask pattern having the circular or oval shape is formed on the surface of the package body  110 , the trench  130  having the predetermined depth may be formed using a wet etching solution. 
         [0028]    The wet etching process may be performed after the dry etching process. At this time, the wet etching process is an isotropic wet etching process. At least one of an acetic acid, a hydrofluoric acid, and a nitric acid may be used as the wet etching solution, or a solution in which the etching solutions are mixed at a predetermined ratio may be used as the wet etching solution. 
         [0029]    The trench  130  may be formed in the package body  110  before or after the cavity  101  is formed. The trench  130  may have a close-loop shape in which a cut portion does not exist or an open-loop shape in which the cut portion exists. 
         [0030]    The plurality of electrodes  112  and  114  are disposed on the surface of the package body  110 . The electrodes  112  and  114  are divided by an opened portion  115  through which the top surface of the package body  110  is partitioned into both sides. Each of the electrodes  112  and  114  may extend from the bottom surface of the cavity  101  up to the top surface, a lateral surface, and a bottom surface of the package body  110 . Both ends of the electrodes  112  and  114  may be disposed on the bottom surface of the package body  110  and used as external electrodes P 1  and P 2 . The electrodes  112  and  114  may be disposed on the trench  130  and in a region except the opened portion  115 . 
         [0031]    E-beam, sputtering, and electro plating deposition processes may be performed to form the electrodes  112  and  114 . 
         [0032]    The plurality of electrodes  112  and  114  may have different electrode patterns according to a structure of the cavity  101  and a mounting position of the light emitting diode  120 , respectively, but it is not limited thereto. Any one of the plurality of electrodes  112  and  114  may have a via structure. 
         [0033]    At least one light emitting diode  120  is disposed on the cavity  101  of the package body  110 . An LED chip may be used as the light emitting diode  120 . 
         [0034]    The light emitting diode  120  may selectively comprise a red LED chip, a blue LED chip, a green LED chip, an ultraviolet (UV) LED chip, and a yellow LED chip, but it is not limited thereto. An electrostatic protection device may be mounted on the package body  110 , or an ion implantation or diffusion process may be performed on the package body  110  to realize the electrostatic protection device. The electrostatic protection device may be realized as a zener diode for protecting the light emitting diode  120 . 
         [0035]    The light emitting diode  120  may be connected to the plurality of electrodes  112  and  114  using wires  120 . Wire bonding, die bonding, and flip bonding processes may be selectively performed according to the chip types of the light emitting diode  120  to connect the light emitting diode  120  to the electrodes  112  and  114 . The connection structure of the light emitting diode  120  may be variously modified according to a type of LED chip, the number of LED chip, and patterns of the electrodes  112  and  114 , but it is not limited thereto. 
         [0036]    The resin material  140  is filled into the cavity  101 . The resin material  140  may comprise a transparent insulating material, e.g., a resin material such as an epoxy resin or silicon or a polymer material, but it is not limited thereto. A liquid resin material is dispensed to form the resin material  140 . 
         [0037]    At least one phosphor of phosphors (not shown) such as red, green, and blue phosphors may be added to the resin material  140 , and this may be changed within the technical scope of embodiments. 
         [0038]    The resin material  140  seals portions of the light emitting diode  120  and the electrodes  112  and  114  to protect them. The lens  150  is disposed on the resin material  140 . A transparent resin material may be dispensed to form the lens  150  before or after the resin material  140  is hardened. The lens  150  may be changed in shape according to a shape of the trench  130  and an amount of the dispensed resin material. 
         [0039]    The trench  140  may prevent the resin material dispensed for forming the lens  150  from overflowing. Thus, an outer shape of the lens  150  may be uniform. 
         [0040]    The outer shape and size of the lens  150  may be changed according to the shape and size of the trench  140 . For example, when the trench has the circular shape, the outer shape of the lens  150  may have a circular shape. Also, when the trench has the oval shape, the outer shape the lens  150  may have an oval shape. An orientation angle may be adjusted according to the shape of the lens  150  using the trench  130 . 
         [0041]    A process for manufacturing the light emitting device according to the first embodiment will now be roughly described. 
         [0042]    The cavity  101  is formed in the inner upper portion of the package body  110 , and the trench  130  is formed around the outside of the cavity  101 . The plurality of electrodes  112  and  114  are formed on the package body  110  and the surface of the cavity  101 . The light emitting diode  120  is mounted on the electrodes  112  and  114 . The resin material is formed in the cavity  101 , and the lens  150  is formed inside the trench  130  on the resin material  140 . 
         [0043]      FIG. 4  is a plan view of a light emitting device according to a second embodiment. In the following description of the second embodiment, duplicate descriptions for elements which are the same as those of the first embodiment will be omitted. 
         [0044]    Referring to  FIG. 4 , in a light emitting device  100 A, a trench  130  is disposed around a cavity  101  of a package body  110 . 
         [0045]    The trench  130  may have a circular shape and be divided into a plurality of trenches  130 A and  130 B that does not communicate with each other. Both ends of the plurality of trenches  130 A and  130 B are spaced a predetermined gap  113  from an opened portion  115 . Thus, the opened portion  115  may divide the plurality of trenches  130 A and  130 B and a plurality of electrodes  112  and  114  into both sides thereof. 
         [0046]    When the trenches  130 A and  130 B are not formed in the opened portion  115 , it may prevent the plurality of electrodes  112  and  114  from being electrically shorted within the opened portion  115 . 
         [0047]    Two or more trenches  130  may be formed, and each of the trenches may have the circular shape. The number of trenches may be changed within the technical scope of embodiments. 
         [0048]      FIG. 5  is a plan view of a light emitting device according to a third embodiment. In the following description of the third embodiment, duplicate descriptions for elements which are the same as those of the first embodiment will be omitted. 
         [0049]    Referring to  FIG. 5 , a light emitting device  100 B comprises a package body  110 A having a rectangular shape and a cavity  101 A having a rectangular shape. The package body  110 A has a horizontal length X and a vertical length Y which are different from each other. The cavity  101 A having the rectangular shape may be disposed inside the package body  110 A. The cavity  101 A may have a shape different from that of the package body  110 A, e.g., a square or circular shape, but it is not limited thereto. 
         [0050]    A trench  130  is disposed around the outside of the cavity  101 A. The trench  130  may have an oval shape. A lens  150  having an oval shape may be manufactured by the trench  130 . Light may be oriented in a specific direction or in a specific region due to the lens  150 . 
         [0051]    The light emitting device  100 B may have a large orientation angle in an X-axis direction and a small orientation angle in a Y-axis direction due to the cavity  101 A having the rectangular shape and the lens  150  having the oval shape. 
         [0052]      FIG. 6  is a perspective view of a light emitting device according to a fourth embodiment. In the following description of the fourth embodiment, duplicate descriptions for elements which are the same as those of the first embodiment will be omitted. 
         [0053]    Referring to  FIG. 6 , a light emitting device  100 C comprises a package body  110  in which a cavity  101 B having a circular shape is provided. An outer shape of the cavity  101 B has the circular shape. 
         [0054]    A resin material is filled in the cavity  101 B, and a lens  150  is disposed on the resin material. An outer surface of the lens  150  is disposed along the trench  130 . 
         [0055]    The trench  130  is spaced the same distance from a circumference of the cavity  101 B. Also, the outer surface of the lens  150  may be spaced the same distance from the circumference of the cavity  101 B. Thus, light emitted from the lens  150  may be irradiated with a smooth distribution. 
         [0056]    Dry and wet etching processes may be selectively performed to form the cavity  101 B having the circular shape. When the wet etching process is performed after the dry etching process is performed, an isotropic wet etching process is performed. Thus, the cavity  101 B may have a lateral surface  117  curved with a predetermined curvature. 
         [0057]    The trench  130  of the package body  110  may be formed after the cavity  101 B is formed first, and the process procedure may be changed. 
         [0058]      FIG. 7  is a side-sectional view of a light emitting device according to a fifth embodiment. In the following description of the fifth embodiment, duplicate descriptions for elements which are the same as those of the first embodiment will be omitted. 
         [0059]    Referring to  FIG. 7 , a light emitting device  100 D has a flat top surface without forming a cavity on a package body  110 . 
         [0060]    A trench  130  having a circular or oval shape is disposed around an outer top surface of the package body  110 . A plurality of electrodes  112  and  114  may be disposed around the outer top surface of the package body  110 . A light emitting diode  120  is attached in the inside or a central region of the trench  130 . The light emitting diode  120  is electrically connected to the plurality of electrodes  112  and  114 . 
         [0061]    According to the fifth embodiment, the number of processes for forming the cavity in the silicon-based package body  110  may be reduced. 
         [0062]    Technical characteristics of the first to fifth embodiments are not limited to a characteristic of each of the embodiments, and any embodiment may be selectively applied to another embodiment within the technical scope of the embodiments. 
         [0063]    In the description of embodiments, it will be understood that when a layer (or film), region, pattern or structure is referred to as being ‘on’ another layer (or film), region, pad or pattern, the terminology of ‘on’ and ‘under’ comprises both the meanings of ‘directly’ and ‘indirectly’. Further, the reference about ‘on’ and ‘under’ each layer will be made on the basis of drawings. 
         [0064]    Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is comprised in at least one embodiment of the invention. The shapes of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
         [0065]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.