Abstract:
A light emitting device is provided. The light emitting device comprises: a package body comprising a multilayer cavity; a first light emitting part comprising a first light emitting device in a first cavity of a first layer area of the multilayer cavity; and a second light emitting part comprising a second light emitting device in a second cavity of a second layer area higher than the first layer area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. 126 and 35 U.S.C. 365 to Korean Patent Application No. 10-2007-0062914 (filed on Jun. 26, 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 GaAs series, AlGaAs series, CaN series, InGaN series, and InGaAlP series, etc. such that various colors can be realized. 
         [0003]    Characteristics of the LED may be determined by materials a compound semiconductor, color and brightness, and a range of brightness intensity. Additionally, the LED is packaged and is applied to various fields such as lightening displays, character displays, and image displays. 
         [0004]    Embodiments provide a light emitting device capable of mounting a light emitting device on each layer after forming a multilayered cavity in a package body. 
         [0005]    Embodiments provide a light emitting device capable of mounting light emitting devices with respectively difference sizes and colors on each layer after forming a multilayered cavity in a package body. 
         [0006]    An embodiment provides a light emitting device comprising: a package body comprising a multilayer cavity; a first light emitting part comprising a first light emitting device in a first cavity of a first layer area of the multilayer cavity; and a second light emitting part comprising a second light emitting device in a second cavity of a second layer area higher than the first layer area. 
         [0007]    An embodiment provides a light emitting device comprising: a package body comprising a cavity of a multilayer area; a first light emitting part comprising a first light emitting device in a first layer area of the package body; and a second light emitting part comprising a second light emitting device smaller than the first light emitting device in a second layer area of the package body. 
         [0008]    An embodiment provides a light emitting device comprising: a package body comprising a multilayer cavity; a first light emitting part comprising a first light emitting device and a first resin material in a first cavity of a first layer area of the multilayer cavity; and a second light emitting part comprising a second light emitting device and a second resin material in a second cavity of a second layer area higher than the first layer area, and emitting at least one light of a wavelength range different from that of the first light emitting part. 
         [0009]    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 
         [0010]      FIG. 1  is a plan view of a light emitting device according to a first embodiment. 
           [0011]      FIG. 2  is a cross-sectional view of  FIG. 1 . 
           [0012]      FIG. 3  is a view illustrating a first driving circuit of a light emitting device of  FIG. 1 . 
           [0013]      FIG. 4  is a view illustrating a second driving circuit of a light emitting device of  FIG. 1 . 
           [0014]      FIG. 5  is a view illustrating a third driving circuit of a light emitting device of  FIG. 1 . 
           [0015]      FIG. 6  is a plan view of a light emitting device according to a second embodiment. 
           [0016]      FIG. 7  is a first driving circuit of a light emitting device of  FIG. 6 . 
           [0017]      FIG. 8  is a view illustrating a second driving circuit of a light emitting device of  FIG. 6 . 
           [0018]      FIG. 9  is a cross-section view of a light emitting device according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0019]    Hereinafter, embodiments will be described with reference to the accompanying drawings. 
         [0020]      FIG. 1  is a plan view of a light emitting device according to a first embodiment,  FIG. 2  is a cross-sectional view of  FIG. 1 . 
         [0021]    Referring to  FIGS. 1 and 2 , a light emitting device  100  comprises a package body  101 , a first light emitting part  110  in an area of a first cavity  111 , and a second light emitting part  120  in an area of a second cavity  121 . 
         [0022]    The package body  101  may be formed of one of a silicon material, a ceramic material, and a resin material (for example, silicon, silicon carbide (SiC), aluminum nitride (AlN), poly phthal amide (PPA), and liquid crystal polymer (LCP)) and also is not limited thereto. 
         [0023]    A multilayered cavity  111  and  121  is formed in the package body  101 . Here, the first cavity  111  is formed in the lowest first layer with respect to the top surface of the package body  101 , and the second cavity  121  is formed in a second layer higher than the first cavity. The first cavity  111  may be formed with a step form in a predetermined area such as the middle or the edge of the second cavity  121 . Positions and areas of the first cavity  111  and the second cavity  121  may respectively vary, and are not limited the above. 
         [0024]    The first cavity  111  is formed with the thickness that is greater than a half of the thickness of the package body  101  and the depth of the minimum 150±5 μm. 
         [0025]    The sides  115  and  125  of the first cavity  111  and the second cavity  121  are inclined toward the outer at a predetermined angle (e.g., 91° to 160°), and a reflective material may be coated thereon. 
         [0026]    The first cavity  111  is used as a first light emitting part  110 , and the second cavity  121  is used as a second light emitting part  120 . That is, the first light emitting part  110  may be formed on a predetermined position (e.g., the middle area) of the second light emitting part  120 . 
         [0027]    A first electrode pad  119  is formed in the first cavity  111 , and a second electrode pad  129  is formed in the second cavity  121 . A plurality of the first electrode pad  119  is formed to be electrically open on the bottom of the first cavity  111 , and a plurality of second electrode pads  129  is formed to be electrically open on the bottom of the second cavity  121 . Additionally, a circuit structure of the first electrode pad  119  and the second electrode pad  129  may vary according to driving methods or electrode patterns, but is not limited thereto. 
         [0028]    Electrode terminals  102  and  103 , electrically connected to the first and second electrode pads  119  and  129 , may be formed on the outer side of the package body  101 . The number of the electrode terminals  102  and  103  may vary according to driving methods, and is not limited thereto. Here, the electrode pads  119  and  129  may be realized with a lead frame type or a gold plate pad type, and are not limited thereto. 
         [0029]    Additionally, as illustrated in  FIG. 2 , a via hole  134  is formed in the package body  101  to electrically connect the electrode pads  119  and  129  of the first and second cavities  111  and  121 . 
         [0030]    A first light emitting device  113  is formed on the first electrode pad  119  of the first cavity  111 , and a second light emitting device  123  is formed on the second electrode pad  129  of the second cavity  121 . Accordingly, an area of the first cavity  111  can be also defined as the first light emitting part  111  and an area of the second cavity  121  can be also defined as the second light emitting part  120 . 
         [0031]    Here, the first light emitting device  113  and the second light emitting device  123  may use a III V group compound semiconductor material such as GaAs, AlGaAs, GaN, InGaN and AlGaInP, or may be selected from a blue light emitting device (LED) chip, a green LED chip, a yellow LED chip, a red LED chip, and an ultra violet (UV) LED chip, and are not limited thereto. 
         [0032]    The first light emitting device  113  is electrically connected to one of a pair of the first electrode pads  119  through a wire  117 , and the second light emitting device  123  is electrically connected to one of a pair of the second electrode pads  129  through a wire  127 . Here, the first and second light emitting devices  113  and  123  are connected to the electrode pads  119  and  129 , respectively, but may vary according to a parallel semiconductor light emitting device or a vertical semiconductor light emitting device. Additionally, the first and second light emitting devices  113  and  123  are connected the electrode pads  119  and  129  using a flip method. 
         [0033]    The size of the first light emitting device  113  may be different from that of the second light emitting device  123 . For example, the first light emitting device  113  may be formed with a size that is more than two times that of the second light emitting device  123 . That is, the first light emitting device  113  may be formed with a relatively large size. 
         [0034]    Light emitted from the first and second light emitting devices  113  and  123  may be the same. For example, the first and second light emitting device  113  and  123  may be a blue LED chip, and are not limited thereto. 
         [0035]    Additionally, the first and second light emitting devices  113  and  123  may be mounted using the same method or different methods. For example, the first light emitting device  113  may be mounted using a flip method and the second light emitting device  123  may be mounted using a wire method. The mounting method is not limited to the above. 
         [0036]    The number of the first light emitting devices  113  formed in the first cavity  111  is different from the number of second light emitting devices  123  formed in the second cavity  121 . There may be at least one first light emitting device  113  and there is a plurality of the second light emitting device  123  at respectively different positions. The number of light emitting devices is not limited to the above. 
         [0037]    A first resin material  130  may be formed in the first cavity  111  and a second resin material  132  may be formed in the second cavity  121 . The first and second resin materials  130  and  132  comprise transparent silicon or epoxy. A fluorescent material may be added to one of the first and second resin materials  130  and  132 . The fluorescence material comprises at least one of a red fluorescence material, a blue fluorescence material, a green fluorescence material, and a yellow fluorescence material. 
         [0038]    Here, in relation to manufacturing processes of the light emitting device  100 , the first and second cavities  111  and  121  having a predetermined depth are formed in the package body  101 . The first and second electrode  119  and  129  are exposed to be electrically open. 
         [0039]    The first light emitting device  113  is mounted on the first electrode pad  119  of the first cavity  111 , and the second light emitting device  123  is mounted on the second electrode pad  129  of the second cavity  121 . A plurality of electrode terminals  102  and  103  are prepared at the outer of the package body  101 , and the number of the electrode terminal  102  and  103  may vary according to internal circuit patterns. 
         [0040]    Next, the first resin material  130  is filled in the first cavity  111  for hardening, and the second resin material  132  is filled in the second cavity  121  for hardening. Here, a yellow fluorescence material may be added to the first resin material  130 . Accordingly, the light emitting device package is completed. 
         [0041]    Additionally, a convex lens or a flat Fresnel lens is attached on the package body  101 , in order to change pointing characteristics of emitting light. The lens may be integrated into the surface of the second resin material  132 . 
         [0042]    On the other hand, the first light emitting part  110  emits a white light at the center of the package body  101  through the first cavity  111 . If the first light emitting device  113  is a blue LED chip, a yellow fluorescence material may be added to the first resin material  130  and the blue light and yellow light may be mixed and emitted as a white light. Additionally, if the first light emitting device  113  is an UV LED, a red fluorescence material, a blue fluorescence material, and a green fluorescence material may be added to the first resin material  130 . Additionally, the first light emitting device  113  may emit a white light by using a three color LED chip. 
         [0043]    On the other hand, the second light emitting part  120  emits a blue light at the second cavity  121 . If the second light emitting device  123  is a blue LED chip, an additional fluorescence material is not added to the second resin material  132 . The second light emitting device  123  may be formed at each corner or the middle of each side of the second cavity  121 . 
         [0044]    The size of the first light emitting device  113  of the first light emitting part  110  may be different from that of the second light emitting device  123  of the second light emitting part  120 . For example, one side length of the first light emitting device  113  may be two times that of the second light emitting device  123 . The first light emitting device  113  may be disposed with the size that is the sum of sizes of a plurality of second light emitting devices  123 . For example, when the four second light emitting devices  123  are disposed, the size of the first light emitting device  113  may be four times that of the one second light emitting device  123 . 
         [0045]    A color temperature of a white light emitted from the first light emitting part  110  may be adjusted by a blue light emitted from the second light emitting part  120 . Here, a color temperature can be controlled depending on the number of the driven second light emitting devices  123  in the second light emitting part  120 . 
         [0046]    Additionally, a yellow fluorescence material may be added to the second resin material  132  of the second light emitting part  120 . Accordingly, light intensity of a white light emitted from the first and second light emitting parts  110  and  120  can be increased. 
         [0047]    A protection device such as shottky diode and zener diode may be formed in the package body  101  in order to protect the light emitting devices  113  and  123  mounted on each layer area. 
         [0048]      FIG. 3  is a view illustrating a first driving circuit of a light emitting device of  FIG. 1 . 
         [0049]    Referring to  FIG. 3 , light emitting devices  113  and  123  are commonly connected to two electrode terminals  102  and  103 . That is, all the light emitting devices  113  and  123  can be simultaneously driven by using the two electrode terminals  102  and  103 . 
         [0050]      FIG. 4  is a view illustrating a second driving circuit of a light emitting device of  FIG. 1 . 
         [0051]    Referring to  FIG. 4 , five light emitting devices  113  to  123  can be separately driven by using five anode electrode terminals A 1  to A 5  and five cathode electrode terminals C 1  to C 5 . This circuit structure can drive all the second light emitting devices  123  or one by one incrementally after driving the first light emitting device  113 . Color rendering of the light emitting device can be improved and a color temperature can be adjusted. 
         [0052]      FIG. 5  is a view illustrating a third driving circuit of a light emitting device of  FIG. 1 . 
         [0053]    Referring to  FIG. 5 , the first light emitting device  113  is connected to two electrode terminals A 6  and C 6 , and a plurality of second light emitting devices  123  is commonly connected to two electrode terminals A 7  and C 7 . That is, the first light emitting device  113  and the second light emitting device  123  can be separately controlled. 
         [0054]    As mentioned above, the first embodiment may comprise two to ten electrode terminals according to driving methods of the first and second light emitting devices  113  and  123 , and is not limited to the driving circuits of  FIGS. 3 to 5 . 
         [0055]      FIG. 6  is a plan view of a light emitting device according to a second embodiment. An overlapping description in the first and second embodiments will be omitted for conciseness. 
         [0056]    Referring to  FIG. 6 , the light emitting device  200  comprises a package body  201 , a first light emitting part  210  in an area of a first cavity  211 , and a second light emitting part  220  in an area of a second cavity  221 . 
         [0057]    The first light emitting part  210  is formed at the first cavity  211  of the package body  201 , and the first light emitting device  213  disposed in the first cavity  211  may be formed of a green LED chip. 
         [0058]    The second light emitting part  220  is formed at the second cavity  221  of the package body  201 , and the second light emitting devices  223  and  225  disposed in the second cavity  221  may be formed of a plurality of red LED chips  223  and blue LED chips  225 . 
         [0059]    The red LED chips  223  may be diagonally disposed to face each other and the blue LED chips  225  may be diagonally disposed to face each other. The arrangement positions of the LED chips  223  and  225  may vary in order to improve light efficiency. 
         [0060]    A first resin material (not shown) is formed in the first cavity  211  and a second resin material (not shown) is formed in the second cavity  221 . An additional fluorescent material may not be added to the first and second resin materials. 
         [0061]    The green LED chip (i.e., the first light emitting device  213 ) may have the size that is more than two times that of the red LED chip (i.e., the second light emitting devices  223 ) or the blue LED chips (i.e., the second light emitting devices  225 ). 
         [0062]    Additionally, the green LED chip  213  may be formed with the size proportional to the sum of sizes of the red LED chip  223  or/and the blue LED chip  225 . Moreover, the size of the green LED chip  213  may be formed with the size less than the sum of sizes of the second light emitting devices  223  and  225 . 
         [0063]    A plurality of electrode terminals  202  and  203  may be formed on the outer side of the package body  201  according to a structure of the electrode pads  219  and  229 . 
         [0064]    By driving the first light emitting device  213  of the first light emitting part  210  and the second light emitting devices  223  and  225  of the second light emitting part  220 , a white light may be emitted. At this point, a relatively large size of the green LED chip is driven and the red LED chip or/and the blue LED chip is/are selectively driven, such that a color temperature and color coordinates can be adjusted. 
         [0065]      FIG. 7  is a first driving circuit of a light emitting device of  FIG. 6 . 
         [0066]    Referring to  FIG. 7 , the green LED chip (i.e., the first light emitting device  213 ) is connected to two electrode terminals A 8  and C 8 , and also the red LED chip (i.e., the second light emitting device  223 ) and the blue LED chip (i.e., the second light emitting device  225 ) are commonly connected to two electrode terminals A 9  and C 9 . By driving the green LED chip  213  and the red LED chip  223  and the blue LED chip  225 , a color temperature and color coordinates can be adjusted. 
         [0067]      FIG. 8  is a view illustrating a second driving circuit of a light emitting device of  FIG. 6 . 
         [0068]    Referring to  FIG. 8 , the green LED chip  213  of the first light emitting device is connected to two electrode terminals A 10  and C 10 , the red LED chip  213  of the second light emitting device is connected to two electrodes terminal A 11  and C 11 , and the blue LED chip  225  of the second light emitting device is connected to two electrode terminals A 12  and C 12 . That is, each of the color LED chips  213 ,  223 , and  225  is connected to two electrode terminals such that it is possible to drive each of the color LED chip  213 ,  223 , and  225  separately. 
         [0069]    According to the second embodiment, each LED chip, each color of the LED chip, each layer can be driven independently according to the driving method of the LED chips. 
         [0070]      FIG. 9  is a cross-section view of a light emitting device according to a third embodiment. 
         [0071]    Referring to  FIG. 9 , a light emitting device  300  comprises a package body  301 , a first light emitting part  310  in an area of a first cavity  311 , and a second light emitting part  320  in an area of a second cavity  321 . 
         [0072]    The first cavity  311  and the second cavity  321  are formed in the package body  301 , and the first cavity  311  is formed at the middle of the second cavity  321 . Coated electrode pads  319  and  329  are formed on the side  315  of the first cavity  311  and the side  325  of the second cavity  321 , respectively. The electrode pads  319  and  329  are formed on the top, the outer side, and the bottom of the package body  301  and also the surface of the cavities  311  and  321 , such that at least two electrode terminals  302  and  303  are formed. 
         [0073]    The first light emitting device  313  and the first resin material  330  are formed in the first cavity  311 , and a plurality of second light emitting devices  323  and second resin materials  332  are formed in the second cavity  321 . The first and second light emitting devices  313  and  323  may be connected through wires  317  and  327 , but are not limited thereto. 
         [0074]    The size and kinds of emitting lights of the first light emitting device  313  and the second light emitting device  323  may vary according to a target light. Additionally, kinds of fluorescent materials added to the first resin material  330  and the second resin material  332  may vary according to the target light. 
         [0075]    The structure of the first and second light emitting devices  313  and  323  and the first and second resin materials  330  and  332  of the third embodiment may adapt components of the first embodiment or/and the second embodiment but is not limited thereto. 
         [0076]    The above mentioned embodiments provide diodes, which can drive each of a white light and three color light separately, to one package, such that the diodes can be used as a flash light source of a mobile terminal. 
         [0077]    Furthermore, it is possible to provide a package that selectively emitting a white light and another color light. Moreover, when a white light is emitted, color rendering and brightness can be improved compared to a related art package by driving white and three color light emitting diodes simultaneously. Furthermore, it is used as a package for indication by using multi color light source. 
         [0078]    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. 
         [0079]    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.