Abstract:
Disclosed are a light emitting device. The light emitting device comprises a board comprising a plurality of lead frames, a light emitting diode chip electrically connected to the lead frames, and a reflective member formed coupled on the board while surrounding the light emitting diode.

Description:
[0001]    The present application claims priority under 35 U.S.C. 365 to Korean Patent Application No. 10-2007-00126195 (filed on Dec. 6, 2007), which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    A light emitting diode (LED) constitutes a light emitting source by using a compound semiconductor material, such as a GaAs-based compound semiconductor material, AlGaAs-based compound semiconductor material, a GaN-based compound semiconductor material, an InGaN-based compound semiconductor material or an InGaAlP-based compound semiconductor material. 
         [0003]    The light emitting diode is packaged and used as a light emitting device for emitting light having various colors. Such a light emitting diode is used as a light source in various fields, such as a lightening indicator for displaying colors, a character indicator, and an image indicator. 
       SUMMARY 
       [0004]    The embodiment provides a light emitting device comprising an LED chip formed on a board and a reflective member provided around the LED chip The embodiment provides a light emitting device comprising a box-type reflective member provided around an LED chip formed on a board. 
         [0005]    An embodiment provides a light emitting device comprising: a board comprising a plurality of lead frames, a light emitting diode (LED) chip electrically connected to the lead frames, and a reflective member coupled on the board while surrounding the light emitting diode. 
         [0006]    An embodiment provides a light emitting device comprising: a board comprising a lead frame, a box-shape reflective member coupled on the board and comprising open upper and lower potions, and an LED chip electrically connected to the lead frame in the reflective member. 
         [0007]    An embodiment provides a light emitting device comprising: a board comprising a plurality of lead frames; a reflective member comprising a sidewall frame and a base frame extend from the sidewall on the board; and a light emitting diode (LED) in the reflective member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view showing a light emitting device according to a first embodiment; 
           [0009]      FIG. 2  is a side sectional view of  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view showing a reflective member illustrated in  FIG. 1 ; 
           [0011]      FIG. 4  is a sectional view taken along line A-A′ of  FIG. 3 ; 
           [0012]      FIGS. 5 to 9  are sectional views showing the manufacturing procedure for a light emitting device according to a first embodiment; 
           [0013]      FIG. 10  is a section view showing a light emitting device according to a second embodiment; and 
           [0014]      FIG. 11  is a perspective view showing a light emitting device array according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0015]    Hereinafter, a light emitting device according to the embodiment will be described with reference to accompanying drawings. 
         [0016]      FIG. 1  is a perspective view showing a light emitting device according to a first embodiment,  FIG. 2  is a side sectional view of  FIG. 1 ,  FIG. 3  is a perspective view showing a reflective member illustrated in  FIG. 1 , and  FIG. 4  is a sectional view taken along line A-A′ of  FIG. 3 . 
         [0017]    Referring to  FIGS. 1 and 2 , the light emitting device  100  comprises a board  110 , an LED chip  130 , a reflective member  150  and a resin material  180 . 
         [0018]    The board  110  comprises one of a metal PCB (printed circuit board), a flexible PCB, a CEM (Contract Electronics Manufacturing) PCB, and an FR (Flame retardant) PCB. The board  110  may comprise a heat slug type PCB, in which a chip mounting region is made from a metallic material, by taking the heat dissipation characteristic into consideration. The board  110  may have a single layer structure or a multi-layer structure, and the embodiment is not limited thereto. 
         [0019]    A plurality of lead frames  113  and  114  are formed on the board  110  such that the lead frames  113  and  114  can be electrically open. Insulating ink  115  can be coated on the board  110 , except for a bonding region of the lead frames  113  and  114  and a chip mounting region. The insulating ink  115  may comprise PSR (photo solder resist) ink, which can improve the reflective efficiency. 
         [0020]    The LED chip  130  is attached to the first lead frame  113 . The LED chip  130  comprises at least one of a color LED chip, such as a red LED chip, a blue LED chip or a green LED chip, and a UV (Ultra-Violet) LED chip. In addition, a plurality of LED chips can be combined in use within the technical scope of the embodiment. 
         [0021]    The LED chip  130  is attached to the first lead frame  113  by a conductive adhesive, and electrically connected to the second lead frame  114  through a wire  132 . The LED chip  130  can be electrically connected to the lead frames  113  and  114  through a plurality of wires or a flip chip scheme. However, the embodiment is not limited thereto. 
         [0022]    At least one fixing hole  117  can be formed in an outer peripheral portion of the board  110 . If plural fixing holes  117  are provided, the fixing holes  117  are formed at both sides of the board  110  and the embodiment is not limited thereto. The fixing hole  117  has a via structure in the board  110 . 
         [0023]    The reflective member  150  has a container shape or a box shape having open upper and lower portions. For instance, the reflective member  150  may have a cylindrical shape or a polyhedral shape. The reflective member  150  is inclined such that the size of a lower portion of the reflective member  150  is smaller than the size of an upper portion of the reflective member  150 . 
         [0024]    The reflective member  150  is provided around the LED chip  130  on the board  110  and serves as a reflective cup. 
         [0025]    Referring to  FIGS. 2 to 4 , the reflective member  150  comprises a sidewall frame  151  and a base frame  153  and is made from a reflective material. For instance, the reflective member  150  is fabricated through an injection molding process by using a resin material, such as PPA (Polyphthalamide) and the like. 
         [0026]    The sidewall frame  151  has a container shape or a box shape and a hole  155  is formed in the sidewall frame  151 . The hole  155  has a circular shape or a polygonal shape. The hole  155  has a shape identical to or different from a shape of the sidewall frame  151 . 
         [0027]    The sidewall frame  151  is inclined outward by a predetermined angle about an axis perpendicular to the base frame  153  and protrudes upward from the base frame  153  by a predetermined height. 
         [0028]    The base frame  153  horizontally extends outward from a lower end of the sidewall frame  151  in parallel to the board  110 . The base frame  153  can be formed at left and right sidewalls of the sidewall frame  151 . However, the embodiment is not limited thereto. 
         [0029]    The reflective member  150  has a size smaller than or identical to a size of the board  110 . 
         [0030]    The base frame  153  is provided at a lower portion thereof with at least one fixing pin  157 . The fixing pin  157  protrudes in the form of a leg. The number and the position of the fixing pin  157  correspond to the number and position of the fixing hole  117  formed in the board  110 . 
         [0031]    Although the reflective member  150  has been described in that the reflective member  150  comprises the base frame  153  and the sidewall frame  151 , the shape, the size and the structure of the reflective member  150  can be modified within the technical scope of the embodiment. 
         [0032]    Referring to  FIGS. 1 and 2 , the base frame  153  makes surface-contact with an upper surface of the board  110  or is fixed thereto by an adhesive, a screw, a hook or an adhesion as well as a pin. The fixing pin  157  of the base frame  153  is inserted into the fixing hole  117  of the board  110 . An end portion  159  of the fixing pin  157  is thermally compressed through a thermal pressing process, so that the fixing pin  157  is prevented from being separated from the fixing hole  117 . 
         [0033]    The fixing pin  157  of the base frame  153  and the fixing hole  117  of the board  110  may have circular shapes or polygonal shapes. However, the embodiment is not limited thereto. In addition, the reflective member  150  can be coupled to the board  110  by using a screw, a hook, an adhesive or an adhesion as well as a pin. 
         [0034]    The resin material  180  is formed in the reflective member  150 . The resin material  180  comprises a light transmitting material, such as silicon or epoxy. A fluorescent substance (not shown), which can be mixed with a color of the LED chip  130 , can be added to the resin material  180 . 
         [0035]      FIGS. 5 to 9  are sectional views showing the manufacturing procedure for the light emitting device according to a first embodiment. 
         [0036]    Referring to  FIG. 5 , a plurality of lead frames  113  and  114 , which are electrically open, are formed on the board  110  in a predetermined pattern. The board  110  comprises one of a metal PCB, a flexible PCB, a CEM PCB, an FR PCB, and a heat slug type PCB. Insulating ink  115 , such as PSR ink, can be coated on the board  110  by a predetermined thickness, except for a bonding region of the lead frames  113  and  114  and a chip mounting region. 
         [0037]    The lead frames  113  and  114  are exposed to the insulating ink  115 . 
         [0038]    Referring to  FIG. 6 , the fixing holes  117  are formed at outer portions of the board  110 . The lead frames  113  and  114  may have openings for the fixing holes  117 . The openings can prevent short or current leakage from occurring in the fixing holes  117  when forming the fixing holes  117 . 
         [0039]    Referring to  FIG. 7 , the reflective member  150  is formed on the board  110  in such a manner that the fixing pin  157  of the reflective member  150  corresponds to the fixing hole  117  of the board  110 . The fixing pin  157  of the reflective member  150  and the fixing hole  117  of the board  110  may have shapes corresponding to each other. For instance, the fixing pin  157  of the reflective member  150  and the fixing hole  117  of the board  110  may have circular shapes or polygonal shapes. 
         [0040]    Referring to  FIG. 8 , when the reflective member  150  is coupled to the board  110 , the base frame  153  of the reflective member  150  makes surface-contact with the upper surface of the board  110 . The reflective member  150  is secured to the board  110  by applying an adhesive or an adhesion between the base frame  153  of the reflective member  150  and the board  110 . 
         [0041]    The fixing pin  157  of the reflective member  150  is inserted into the fixing hole  117  of the board  110 . The end portion  159  of the fixing pin  157  protrudes downward out of the board  110  and is thermally compressed by applying heat to the end portion  159  of the fixing pin  157 . Thus, the fixing pin  157  can be prevented from being separated from the fixing hole  117  by the end portion  159  of the fixing pin  157 . 
         [0042]    Referring to  FIG. 9 , the LED chip  130  is mounted on the board  110  after the reflective member  150  has been coupled to the board  110 . 
         [0043]    The LED chip  130  is attached to the first lead frame  113  in the reflective member  150  and electrically connected to the second lead frame  114  through the wire  132 . The LED chip  130  can be electrically connected to the lead frame  113  by a conductive adhesive. In addition, the LED chip  130  can be electrically connected on the lead frames  113  and  114  through wires or a flip chip scheme. However, the embodiment is not limited thereto. 
         [0044]    The LED chip  130  comprises at least one of a color LED chip, such as a red LED chip, a blue LED chip or a green LED chip, and a UV LED chip. In addition, a plurality of LED chips can be combined in use within the technical scope of the embodiment. 
         [0045]    The resin material  180  is filled in the hole  155  of the reflective member  150 . The resin material  180  comprises silicon or epoxy. A fluorescent substance can be added to the resin material  180 . 
         [0046]    The LED chip  130  can be mounted on the on the board  110  after or before the reflective member  150  has been coupled to the board  110 . The surface of the resin material  180  has a flat shape, a concave lens shape or a convex lens shape. However, the embodiment is not limited thereto. 
         [0047]      FIG. 10  is a section view showing a light emitting device according to a second embodiment. In the description of the second embodiment, elements that have been described in the first embodiment will not be further described in order to avoid redundancy. 
         [0048]    Referring to  FIG. 10 , the light emitting device  100  comprises a lens  182  provided on the resin material  180 . 
         [0049]    A stopper  161  is formed at an inner upper portion of the sidewall frame  151  of the reflective member  150 . The stopper  161  protrudes from the inner peripheral surface of the sidewall frame  151 . 
         [0050]    The resin material  180  is formed in the reflective member  150  and has a convex upper portion. The lens  182  is formed on the convex upper portion of the resin material  180  and the stopper  161  supports a lower peripheral portion of the lens  182 . 
         [0051]      FIG. 11  is a perspective view showing a light emitting device array according to a third embodiment. In the description of the third embodiment, elements that have been described in the first embodiment will not be further described in order to avoid redundancy. 
         [0052]    Referring to  FIG. 11 , the light emitting device array  100 A comprises a reflective member assembly  101  having a plurality of reflective members  150 A to  15 ON prepared in the form of an array, and an array board  103  disposed below the reflective member assembly  101 . 
         [0053]    The reflective members  150 A to  15 ON are fabricated through an injection molding process such that the reflective members  150 A to  150 N are spaced apart from each other by a predetermined distance (D 1 ). A hole is formed in each reflective member and a fixing pin  157  protrudes downward from a bottom surface of the reflective member assembly  101 . 
         [0054]    The array board  103  has board regions  110 A to  110 N, which are spaced part from each other by a predetermined distance (D 1 ). The board regions  110 A to  110 N correspond to the reflective members  150 A to  150 N of the reflective member assembly  101 , respectively. The lead frames  113  and  114  and the fixing holes  117  are formed in the board regions  110 A to  110 N of the array board  103 . 
         [0055]    At least on LED chip (not shown) can be mounted on the lead frames  113  and  114 . The embodiment does not limit the number and the type of the LED chips. 
         [0056]    The LED chip can be mounted on the on the array board  103  after or before the reflective member assembly  101  has been coupled to the array board  113 . 
         [0057]    The light emitting device array may be cut into at least one the reflective members unit for using as a light emitting device. 
         [0058]    The light emitting device according to the embodiment comprises the board assembled with the reflective member so that the light emitting device can be simply fabricated. In addition, since various types of boards can be applied to the light emitting device of the embodiment, the board having superior heat dissipation characteristic can be adopted in the embodiment. In addition, the light emitting device can improve the heat dissipation characteristics and the light efficiency. Further, the productivity can be improved by aligning the reflective members on the board in the form of an array. 
         [0059]    When it is described in the embodiment that a layer (film), a region, a pattern, or structures are formed “on” or “under” aboard, another layer (film), another region, or another pattern, it means that they are “directly” or “indirectly” formed “on” or “under” the board, another layer, another region, or another pattern. 
         [0060]    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 appearances 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. 
         [0061]    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.