Abstract:
An LED package module according to an aspect of the invention may include: a substrate having predetermined electrodes thereon; a plurality of LED chips mounted onto the substrate, separated from each other at predetermined intervals, and electrically connected to the electrodes; a first color resin portion molded around at least one of the plurality of LED chips; a second color resin portion molded around all of the LED chips except for the LED chip around which the first color resin portion is molded, and having a different color from the first color resin portion; and a third color resin portion encompassing both the first color resin portion and the second color resin portion and having a different color from the first color resin portion and the second color resin portion. Accordingly, a reduction in luminous efficiency of an LED caused by yellowing is prevented to thereby increase luminous efficiency and achieve a reduction in size.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of Korean Patent Application No. 10-2008-0101265 filed on Oct. 15, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to LED package modules, and more particularly, to an LED package module for lighting that is used in lighting components or devices. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, light emitting diode (LED) package modules for lighting have silicon lenses and packages mounted with LED chips, phosphors and resin. LED package optical systems maintain stable optical output in an optimum state, protect light source devices, and ensure the reliability of light source devices for long-term use in any environment. 
         [0006]    Recently, applications and requirements for lighting for various purposes, including landscape lighting and other functional lighting, have greatly increased. The demand for high-power output has also increased accordingly. In order to meet various applications, the reduction in size, thickness, and weight has been demanded for the practicality and convenience of design. Therefore, heat-dissipating designs and mechanical designs of LED packages have been important issues. 
         [0007]    Research and development of mechanical packages and ceramic packages has been conducted for heat dissipation. In terms of mechanical design, chip-on-board (COB) technology has been used. Compared to existing plastic molding and lead-frame packaging technologies, the above-described technologies are very effective in the areas of mechanical design and heat-dissipating design. 
         [0008]    However, lighting package modules using ultra violet (UV) LEDs may significantly reduce luminous efficiency due to the yellowing of plastics exposed to ultraviolet rays for extended periods. 
       SUMMARY OF THE INVENTION 
       [0009]    An aspect of the present invention provides an LED package module that prevents a reduction in luminous efficiency of an LED caused by yellowing to thereby increase luminous efficiency and achieve a reduction in size. 
         [0010]    According to an aspect of the present invention, there is provided an LED package module including: a substrate having predetermined electrodes thereon; a plurality of LED chips mounted onto the substrate, separated from each other at predetermined intervals, and electrically connected to the electrodes; a first color resin portion molded around at least one of the plurality of LED chips; a second color resin portion molded around all of the LED chips except for the LED chip around which the first color resin portion is molded, and having a different color from the first color resin portion; and a third color resin portion encompassing both the first color resin portion and the second color resin portion and having a different color from first color resin portion and the second color resin portion. 
         [0011]    The first color resin portion may be a red resin portion including a red phosphor, the second color resin portion may be a green resin portion including a green phosphor, and the third color resin portion may be a blue resin portion including a blue phosphor. 
         [0012]    Each of the red resin portion and the green resin portion may be molded around one LED chip on the substrate and be substantially in the form of a dome, and the blue resin portion may be molded around both the red resin portion and the green resin portion and be substantially in the form of a dome. 
         [0013]    The LED package module may further include a body including a first layer provided on the substrate and receiving the plurality of separated LED chips, the red resin portion, and the green resin portion, and a second layer provided on the first layer and receiving the blue resin portion encompassing the red resin portion and the green resin portion. 
         [0014]    The body may include: a plurality of cavities provided in the first layer, receiving the plurality of LED chips, and filled with the red resin portion and the green resin portion; and an opening provided in the second layer and filled with the blue resin portion to encompass both the red resin portion and the green resin portion. 
         [0015]    A plurality of cavities may be provided on the substrate, receive the plurality of LED chips, and be filled with the red resin portion and the green resin portion, and an opening may be formed above the cavities and filled with the blue resin portion to encompass the red resin portion and the green resin portion. 
         [0016]    The plurality of LED chips may be inclined at predetermined angles so that central lines of optical paths of the plurality of LED chips cross each other. 
         [0017]    A bottom surface of each of the plurality of cavities to be mounted with the separated LED chips may be inclined at a predetermined angle to form an inclined surface so that central lines of optical paths of the plurality of LED chips cross each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0019]      FIG. 1  is a view schematically illustrating a lateral cross section of an LED package module according to an exemplary embodiment of the present invention; 
           [0020]      FIG. 2  is a plan view schematically illustrating the LED package module, illustrated in  FIG. 1 ; 
           [0021]      FIG. 3  is a view schematically illustrating an LED package module according to another exemplary embodiment of the present invention; and 
           [0022]      FIG. 4  is a view schematically illustrating a lateral cross-section of an LED package module according to another exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
         [0024]    First, with reference to  FIGS. 1 and 2 , an LED package module according to an exemplary embodiment of the invention will be described.  FIG. 1  is a view schematically illustrating a lateral cross-section of an LED package module according to an exemplary embodiment of the invention.  FIG. 2  is a plan view schematically illustrating the LED package module, shown in  FIG. 1 . 
         [0025]    As shown in  FIGS. 1 and 2 , an LED package module according to an exemplary embodiment of the invention includes a substrate  10 , a body  20 , and a plurality of LED chips L 1  and L 2 . The LED chips L 1  and L 2  are positioned in the body  20  and mounted onto the substrate  10  by bonding. 
         [0026]    The substrate  10  is a ceramic substrate on which electrode patterns  12  are formed to provide an electrical connection with other components. Via electrodes  11  are formed in the substrate  10  to electrically connect the substrate  10  and the LED chips L 1  and L 2  mounted above the electrode patterns  12 . 
         [0027]    Heat sinks  15  are provided to dissipate heat from the LED chips L 1  and L 2 . Vias  14  are formed through the substrate  10  such that the heat sinks  15  and the LED chips L 1  and L 2  are thermally connected to each other. 
         [0028]    The body  20  has two layers. That is, a first layer  21  forms the lower side of the body  20 , and a second layer  22  forms the upper side thereof. The first layer  21  and the second layer  22  may be separately manufactured and then connected to each other. Alternatively, the first layer  21  and the second layer  22  may be formed integrally with each other. 
         [0029]    The first layer  21  includes a plurality of cavities  31  and  32  in which the plurality of LED chips L 1  and L 2  are respectively received. 
         [0030]    Each of the cavities  31  and  32  has a reflective surface inclined at a predetermined angle and a bottom surface through which the via  14  and the via electrode  11  are exposed. 
         [0031]    The via  14  is thermally connected to the LED chip L 1  or L 2 , and the via electrode  11  is connected to the LED chip L 1  or L 2  by bonding using wires w or flip chip bonding. 
         [0032]    The cavities  31  and  32  are filled with a red resin portion  41  including a red phosphor and a green resin portion  42  including a green phosphor, respectively. 
         [0033]    Preferably, the heights of the red resin portion  41  and the green resin portion  42  filling the cavities  31  and  32 , respectively, do not exceed the height of the interface between the first layer  21  and the second layer  22 . 
         [0034]    An opening  33  is formed in the second layer  22 . As shown in  FIGS. 1 and 2 , the opening  33  is preferably large enough to encompass both the cavities  31  and  32  that are formed in the first layer  21 . 
         [0035]    Then, the opening  33  is filled with a blue resin portion  43  including a blue phosphor. 
         [0036]    That is, the blue resin portion  43  fills the opening  33  to thereby encompass the red resin portion  41  and the green resin portion  42  that fill the cavities  31  and  32 , respectively. 
         [0037]    That is, the red resin portion  41  and the green resin portion  42  are disposed adjacently on the first layer  21 . The blue resin portion  43  is placed in the opening  33  of the second layer  22  formed on the first layer  21 . 
         [0038]    Light generated from the LED chip L 1  around which the red resin portion  41  is molded supplies energy to the red phosphor included in the red resin portion  41 , thereby generating red light. Light generated from the LED chip L 2  around which the green resin portion  42  is molded supplies energy to the green phosphor included in the green resin portion  42 , thereby generating green light. 
         [0039]    Here, the red light and the green light move toward the blue resin portion  43 . In the blue resin portion  43 , the red light and the green light are mixed together and affected by the blue phosphor included in the blue resin portion  43  to thereby generate white light, which is then emitted to the outside. 
         [0040]    As the red resin portion  41  and the green resin portion  42  are disposed in the first layer  21 , and the blue resin portion  43  is disposed in the second layer  22  formed on the first layer  21 , light ultimately passes through the blue resin portion  43  to thereby generate white light with high luminance. 
         [0041]    In this embodiment, illustrated in  FIGS. 1 and 2 , the red resin portion  41  and the green resin portion  42  are disposed in the first layer  21 , and the blue resin portion  43  is disposed in the second layer  22  formed on the first layer  21 . However, the invention is not limited thereto, and the arrangement of the red, green, and blue resin portions can be changed. 
         [0042]    However, when the color arrangement is changed, white light is not necessarily emitted. 
         [0043]    Referring to  FIG. 3 , an LED package module according to another exemplary embodiment of the invention will be described. 
         [0044]    Like the body of the LED package module according to the embodiment, illustrated in  FIGS. 1 and 2 , the body  20  of an LED package module according to the embodiment, illustrated in  FIG. 3 , includes a first layer  21  and a second layer  22 . The first layer  21  includes a plurality of cavities  31  and  32 . The second layer  22  has an opening  33  that is large enough to encompass both the cavities  31  and  32 . 
         [0045]    Here, in the same manner as the first and second layers of the LED package module according to the embodiment, shown in  FIG. 1 , the first layer  21  and the second layer  22  may be separately manufactured and then are connected to each other, or be formed integrally with each other. 
         [0046]    The cavities  31  and  32 , formed in the first layer  21  of the body  20  of the LED package module according to the embodiment, shown in  FIG. 3 , include inclined surfaces  31   a  and  32   a , respectively. That is, the bottom surface of each of the cavities  31  and  32  is inclined at a predetermined angle. 
         [0047]    That is, in the embodiment, illustrated in  FIG. 3 , the bottom surfaces of the cavities  31  and  32  form the inclined surfaces  31   a  and  32   a , respectively, such that the central line of the optical path of a first LED chip L 1  and the central line of the optical path of a second LED chip L 2  cross each other. 
         [0048]    As shown in  FIG. 3 , the cavities  31  and  32  have the inclined surfaces  31   a  and  32   a  at the bottom surfaces thereof, respectively, so that the LED chips L 1  and L 2  are inclined in a direction in which the LED chips L 1  and L 2  face each other. As a result, red light and green light can be effectively mixed together to thereby generate high quality white light. 
         [0049]    In  FIG. 3 , the two LED chips in the cavities are mounted so that they are inclined at predetermined angles in a direction in which they face each other. However, the invention is not limited thereto. When more than two LED chips are mounted, the LED chips are inclined at predetermined angles in a direction in which all of the LED chips face each other, so that color separation can be prevented and color mixing can be more efficiently performed. 
         [0050]    Since the LED package module according to this embodiment is substantially the same as the LED package module according to the embodiment, illustrated in  FIGS. 1 and 2 , except for the inclined surfaces formed on the cavities, a detailed description thereof will be omitted. 
         [0051]    An LED package module according to another exemplary embodiment of the invention will now be described with reference to  FIG. 4 . 
         [0052]    Basically, the LED package module according to the embodiment, illustrated in  FIG. 4 , does not have a body. 
         [0053]    That is, a plurality of LED chips L 1  and L 2  are separated from each other at a predetermined interval and mounted onto a substrate  10 . Resins having different colors are applied to the LED chips L 1  and L 2 . 
         [0054]    In the LED package module according to the embodiment of the invention, illustrated in  FIG. 4 , the LED chip L 1  is mounted onto the first substrate  10 , and a red resin portion  41  is in the form of a dome and molded around the first LED chip L 1 . 
         [0055]    When the second LED chip L 2  is separated from the first LED chip L 1 , a green resin portion  42  is in the form of a dome and molded around the second LED chip L 2 . 
         [0056]    Further, a blue resin portion  43  is in the form of a dome and molded around the red resin portion  41  and the green resin portion  42 . 
         [0057]    That is, the red resin portion  41  and the green resin portion  42  are disposed adjacently on the substrate  10 , and the blue resin portion  43  encompasses the red resin portion  41  and the green resin portion  42 . 
         [0058]    Light generated from the LED chip L 1  around which the red resin portion  41  is molded supplies energy to a red phosphor included in the red resin portion  41 , thereby generating red light. Light generated from the LED chip L 2  around which the green resin portion  42  is molded supplies energy to a green phosphor included in the green resin portion  42 , generating green light. 
         [0059]    Here, red light and green light move toward the blue resin portion  43 . In the blue resin portion  43 , the red light and the green light are mixed together and affected by the blue phosphor included in the blue resin portion  43  to generate white light, which is then emitted to the outside. 
         [0060]    Here, like the embodiment, illustrated in  FIG. 1 , the arrangement of the red resin portion, the green resin portion, and the blue resin portion may be changed. Here, white light is not necessarily emitted from the LED package module. 
         [0061]    Since the LED package module according to this embodiment, illustrated in  FIG. 4 , is substantially the same as the LED package module according to the embodiment, illustrated in  FIG. 1 , that is, the substrate  10  and the via electrodes formed thereon, except for the above-described features, a detailed description thereof will be omitted. 
         [0062]    As set forth above, according to exemplary embodiments of the invention, the LED package module prevents a reduction in luminous efficiency of an LED caused by yellowing, thereby increasing luminous efficiency and achieving a reduction in size. 
         [0063]    While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.