Abstract:
A light emitting device package according to embodiments comprises: a package body; a lead frame on the package body; a light emitting device supported by the package body and electrically connected with the lead frame; a filling material surrounding the light emitting device; and a phosphor layer comprising phosphors on the filling material.

Description:
The present application is a Continuation of co-pending application Ser. No. 12/667,743 filed on Jan. 5, 2010, which is the national phase of PCT International Application No. PCT/KR2008/003960 filed on Jul. 4, 2008, which claims the benefit under 35 U.S.C. §119 of Korean Patent Application No. 10-2007-0067986 filed in Korea on Jul. 6, 2007. The entire contents of all of the above applications are hereby incorporated by reference. 
    
    
     BACKGROUND 
     1. Field of the Disclosure 
     The present disclosure relates to a light emitting device package. 
     2. Description of the Related Art 
     A light emitting diode (LED) is a semiconductor light emitting device converting a current into light. 
     The wavelength of light emitted from the LED depends on a semiconductor material used for manufacturing the LED because the wavelength of the emitted light depends on a band-gap of a semiconductor material representing an energy difference between electrons in a valence band and electrons in a conduction band. 
     Recently, as the brightness of the LED increases more and more, the LED is used as a light source for a display device, a lighting apparatus, and a light source for an automobile. The LED can be realized to emit white light with excellent efficiency by using a fluorescent material or combining LEDs of various colors. 
     To use the LED for this purpose, the operation voltage of a device should be lowered and a light emitting efficiency and brightness should be high. 
     In manufacturing such an LED, a silicon gel or an epoxy resin is coated on an LED chip of a package to increase efficiency and protect the LED chip. At this point, a method for coating a silicon gel or an epoxy resin, and a coating shape have a great influence on a light emitting efficiency. 
     Also, recently, a light emitting device package includes a lens to increase a light emitting efficiency. Such a lens not only increases a light emitting efficiency but also controls light distribution characteristic to a desired angle. 
     In a method of realizing various colors of an LED, a method of coating phosphor on an LED chip to realize various colors is generally used. At this point, a light emitting efficiency can change depending on a method and a position by which the phosphors are coated. 
     BRIEF SUMMARY 
     Embodiments provide a light emitting device package of a new structure. 
     Embodiments also provide a light emitting device package that can increase a light emitting efficiency without an additional process by manufacturing a lens shape using a dispensing method during a process of coating a silicon gel or an epoxy resin on the light emitting device package. 
     Embodiments also provide a light emitting device package that can reduce an influence by heat emitted from a light emitting device, on phosphors. 
     Embodiments also provide a light emitting device package that allows light exited from phosphors not to be absorbed to a light emitting device but to be effectively emitted to the outside. 
     Embodiments also provide a light emitting device package with an improved color uniformity. 
     In an embodiment, a light emitting device package comprises: a package body; a lead frame in the package body; a light emitting device supported by the package body and electrically connected with the lead frame; a filling material surrounding the light emitting device; and a phosphor layer comprising phosphors on the filling material. 
     In an embodiment, a light emitting device package comprises: a package body; a lead frame in the package body; a light emitting device supported by the package body and electrically connected with the lead frame; a filling material surrounding the light emitting device and having a dome-shaped upper surface; a phosphor layer comprising phosphors on the filling material; and a molding portion having a dome-shape upper shape on the phosphor layer. 
     Embodiments can provide a light emitting device package of a new structure. 
     Embodiments can also provide a light emitting device package that can increase a light emitting efficiency without an additional process by manufacturing a lens shape using a dispensing method during a process of coating a silicon gel or an epoxy resin on the light emitting device package. 
     Embodiments can also provide a light emitting device package that can reduce an influence by heat emitted from a light emitting device, on phosphors. 
     Embodiments can also provide a light emitting device package that allows light exited from phosphors not to be absorbed to a light emitting device but to be effectively emitted to the outside. 
     Embodiments also provide a light emitting device package with an improved color uniformity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view explaining a light emitting device package according to an embodiment 1. 
         FIG. 2  is a view explaining a light emitting device package according to an embodiment 2. 
         FIGS. 3 to 5  are views explaining a light emitting device package according to an embodiment 3. 
         FIGS. 6 to 8  are views explaining a light emitting device package according to an embodiment 4. 
         FIGS. 9 to 11  are views explaining a light emitting device package according to an embodiment 5. 
         FIGS. 12 to 14  are views explaining a light emitting device package according to an embodiment 6. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present disclosure with reference to the accompanying drawings. 
     While numerous modifications and variations are allowed by the present disclosure, specific embodiments thereof are exemplarily illustrated in the drawings, which will be described in detail. However, the embodiments are not intended for limiting the present disclosure to the disclosed specific forms but rather the present disclosure include all modifications, equivalents, and alternatives matching with the spirit of the present disclosure as defined by the appended claims. 
     Same reference numerals denote the same elements through the descriptions of the drawings. The dimensions of layers and regions in the drawings are exaggerated for clarity. 
     In the case where an element such as a layer, region, and a substrate is mentioned as being “on” another element, it is understood that it is directly on the another element or an intervening element may exist therebetween. In the case where a portion of an element such as a surface is expressed as an “inner portion”, it is understood that the portion is located far from the outer side of a device than other portions of the element. 
     It is understood that these terminologies are intended to include other directions of a device in addition to a direction described in the drawings. Last, a terminology “directly” means that there is no intervening element. As used here, a terminology “and/or” includes one or any combination of two or more, and all combinations of described associated items. 
     Embodiment 1 
       FIG. 1  is a view explaining a light emitting device package according to an embodiment 1. 
     Referring to  FIG. 1 , in the light emitting device package, a light emitting device  20  is mounted in a light emitting device mounting portion  11  provided to a package body  15 . The light emitting device  20  is electrically connected, through wires  16 , to first and second lead frames  12  and  13  connected to the outside by passing through the package body  15 . A heatsink portion  50  can be disposed under the light emitting device  20 . 
     The light emitting device mounting portion  11  is a space formed by the first and second lead frames  12  and  13 , the heatsink portion  50 , and the package body  15 , and provides a cavity in which the light emitting device  20  can be mounted. 
     The first and second lead frames  12  and  13 , and the heatsink portion  50  can be formed of copper, and a reflective layer formed of Ag or Al and having a high reflectivity can be formed on the surface of them. 
     The upper portion of the light emitting device mounting portion  11  including the light emitting device  20  is filled with a filling material  30 , and a lens  40  is attached on the filling material  30 . The filling material  30  can include phosphors. 
     At this point, the package body  15  is formed by injection molding with the first and second lead frames  12  and  13 , and the heatsink portion  50  disposed. 
     Therefore, the first and second lead frames  12  and  13 , and the heatsink portion  50  can be fixed by the package body  15 . The first and second lead frames  12  and  13  can pass through the package body  15  and be connected to the outside. 
     The package body  15  can be formed of a plastic material that can be formed by injection molding. 
     For the light emitting device  20 , a horizontal light emitting device, a flip-chip bonded light emitting device, and a vertical light emitting device can be applied depending on the formation position of an electrode layer. 
     Here, the vertical light emitting device can have a structure in which a light emitting device is formed on a support layer formed of metal or a semiconductor. 
     In the light emitting device package according to the embodiment, the lens  40  is attached. The lens  40  can improve the light power of the light emitting device, and control a light distribution characteristic. 
     Embodiment 2 
       FIG. 2  is a view explaining a light emitting device package according to an embodiment 2. 
     Hereinafter, the embodiment 2 is described with reference to  FIG. 2 . Parts not explained can be the same as those of the embodiment 1. 
     As in the embodiment 1, a separately manufactured lens can be attached to the light emitting device package. Also, as in  FIG. 2 , a silicon gel or an epoxy resin is dispensed on a light emitting device  20  to form a lens  60  also serving as a filling material. The lens  60  can include phosphors. 
     Particularly, since the lens  60  is formed using a dispensing method, a separate lens manufacturing is not required. Since the lens  60  can be simultaneously formed during a process of filling a filling material on the light emitting device  20 , the lens  60  can be formed without an additional process, so that light power can be improved. 
     Dispensing is a method of coating and forming liquid gel or resin using a nozzle, which is similar to an inkjet method. The dispensing includes hardening coated gel or resin. 
     To realize a light emitting device package emitting white, green, red, and yellow light, phosphors are coated on a blue or near ultraviolet light emitting device. According to the light emitting device package of the embodiment, phosphors are mixed in the form of powder with silicon gel or an epoxy resin, and coated on the light emitting device  20 . 
     For example, in the case where yellow phosphors are coated on a blue light emitting device, blue light emitted from the blue light emitting device excites yellow phosphors to generate yellow light. The blue light is mixed with the yellow light to create white light. 
     Also, to prevent a phenomenon that emission from the phosphors is absorbed in a chip of the light emitting device  20  and so efficiency reduces, silicon gel or an epoxy resin is filled on the chip of the light emitting device  20 , and the phosphors are mixed with the silicon gel or the epoxy resin and coated thereon to form a lens, so that a white light emitting device package of a high efficiency can be realized. 
     At this point, in coating the silicon gel or the epoxy resin on the light emitting device  20 , a dispersing agent or a diffusing agent can be mixed and coated in order to effectively disperse light emitted from the light emitting device  20 , and increase the refractive index of a resin and thus improve light extraction of the light emitting device chip. 
     Embodiment 3 
       FIGS. 3 to 5  are views explaining a light emitting device package according to an embodiment 3. 
     The embodiment 3 is described with reference to  FIGS. 3 to 5 . Parts not explained can be the same as those of the previous embodiment. 
     Referring to  FIG. 3 , a light emitting device  20  is mounted in a light emitting device mounting portion  11  provided to a package body  15 . The light emitting device  20  is electrically connected, through wires  16 , to first and second lead frames  12  and  13  connected to the outside by passing through the package body  15 . 
     A filling material  31  including phosphors are filled on the light emitting device  20 . The filling material  31  formed by mixing phosphors with a synthetic resin such as a silicon gel and an epoxy resin fills the inside of the light emitting device mounting portion  11 . 
     At this point, the phosphors can be phosphors that can emit various colors. That is, the phosphors can be materials emitting blue, green, yellow, and red light. 
     A molding portion  41  can be formed on the filling material  31  by coating silicon gel or an epoxy resin using various methods. That is, the molding portion  41  can be formed in a lens shape as illustrated in  FIG. 3 , or a plate-shaped molding portion  42  can be formed as illustrated in  FIG. 4 . 
     Meanwhile, referring to  FIG. 5 , the molding portion  43  can be formed lower than the case of  FIG. 4  to lower the height of the whole package. At this point, the molding portion  43  having this low height can be obtained by forming low the height of the package body  15 , and forming the molding portion  43  up to the height of the package body  15 . 
     Embodiment 4 
       FIGS. 6 to 8  are views explaining a light emitting device package according to an embodiment 4. The embodiment 4 is described with reference to  FIGS. 6 to 8 . Parts not explained can be the same as those of the previous embodiment. 
     Referring to  FIG. 6 , a light emitting device  20  is mounted in a light emitting device mounting portion  11  provided to a package body  15 . The light emitting device  20  is electrically connected, through wires  16 , to first and second lead frames  12  and  13  connected to the outside by passing through the package body  15 . 
     A filling material  32  formed of silicon gel or an epoxy resin is filled on the light emitting device mounting portion  11  on the light emitting device  20 . The filling material  32  does not include phosphors. 
     Also, a phosphor layer  33  including phosphors can be formed on the filling material  32 . The phosphor layer  33  can be formed by mixing the phosphors with a silicon gel or an epoxy resin. 
     That is, to prevent a phenomenon that emission from the phosphors is absorbed in the light emitting device  20  and so emission efficiency reduces, the filling material  32  formed of silicon gel or an epoxy resin is filled on the light emitting device  20 , and the phosphor layer  33  formed by mixing the phosphors with silicon gel or the epoxy resin is coated thereon, so that a white light emitting device package of a high efficiency can be realized. 
     Also, since the phosphor layer  33  including the phosphors are spaced from the light emitting device  20  by the filling material  32 , change in the characteristics of the phosphors by heat emitted from the light emitting device  20  can be prevented. 
     Also, since the phosphor layer  33  including the phosphors are spaced from the light emitting device  20  by the filling material  32 , color uniformity can improve. 
     A lens shaped molding portion  42  can be formed on the phosphor layer  33  using a silicon gel or an epoxy resin as illustrated in  FIG. 6 . Also, the molding portion may not be formed on the phosphor layer  33  as illustrated in  FIG. 7 . 
     Meanwhile, referring to  FIG. 8 , in forming the filling material  34  on the light emitting device  20 , a dispersing agent or a diffusing agent can be mixed in order to effectively disperse light emitted from the light emitting device  20 , and increase the refractive index of the resin and thus improve light extraction of the light emitting device  20 . 
     The dispersing agent or the diffusing agent  70  can be formed using at least one of SiO 2 , TiO 2 , and ZrO 2 . The dispersing agent or the diffusing agent  70  can be included when the phosphor layer  33  or the molding portion  42  as well as the filling material is formed. 
     A phosphor layer  33  including phosphors can be formed on the filling material  34  to change the wavelength of light emitted from the light emitting device  20 . 
     Embodiment 5 
       FIGS. 9 to 11  are views explaining a light emitting device package according to an embodiment 5. 
     Hereinafter, the embodiment 5 is described with reference to  FIGS. 9 to 11 . Parts not explained can be the same as those of the previous embodiment. 
     Referring to  FIG. 9 , a light emitting device  20  is mounted in a light emitting device mounting portion  11  provided to a package body  15 . The light emitting device  20  is electrically connected, through wires  16 , to first and second lead frames  12  and  13  connected to the outside by passing through the package body  15 . 
     A dome-shaped filling material  35  formed of silicon gel or an epoxy resin is filled on the light emitting device mounting portion  11  on the light emitting device  20 . 
     The dome-shaped filling material  35  is designed for improving light extraction efficiency. At this point, the dome-shape of a hemisphere can be more effective. Light passes vertically to a hemisphere surface regardless of the starting angle of the light. 
     Therefore, a high transmittance corresponding to a incident angle normal to the hemisphere surface can be obtained, and a total reflection angle does not exist any more. 
     Referring to  FIG. 9 , the dome-shaped filling material  35  is formed on a silicon gel or an epoxy resin on the light emitting device mounting portion  11 , and a phosphor layer  33  including phosphors is formed on the filling material  35  in order to improve the efficiency of the phosphor layer. 
     A lens-shaped molding portion  41  can be formed on the phosphor layer  33 . 
     Meanwhile, referring to  FIG. 10 , a dome-shaped filling material  36  formed of a silicon gel or an epoxy resin mixed with a dispersing agent or a diffusing agent  70  having a high refractive index can be formed. 
     Also, referring to  FIG. 11 , a dome-shaped phosphor layer  37  can be formed on the light emitting device mounting portion  11  in which the light emitting device  20  is mounted. Since the refractive index of the phosphor layer  37  is greater than that of the silicon gel, the phosphor layer  37  can be more effective in improving light extraction efficiency. A lens-shaped molding portion  41  can be located on the dome-shaped phosphor layer  37 . 
     Embodiment 6 
       FIGS. 12 to 14  are views explaining a light emitting device package according to an embodiment 6. 
     Hereinafter, the embodiment 6 is described with reference to  FIGS. 12 to 14 . Parts not explained can be the same as those of the previous embodiment. 
     Referring to  FIG. 12 , a light emitting device  20  is mounted in a light emitting device mounting portion  11  provided to a package body  15 . The light emitting device  20  is electrically connected, through wires  16 , to first and second lead frames  12  and  13  connected to the outside by passing through the package body  15 . 
     A dome-shaped molding portion  43  formed of silicon gel or an epoxy resin is filled on the light emitting device mounting portion  11  on the light emitting device  20 . The molding portion  43  is mixed with phosphors. The molding portion  43  is molded in a dome-shape using a dispensing method to realize various colors and can serve as a lens. 
       FIG. 12  illustrates the entire upper space of the light emitting device mounting portion  11  is filled with the molding portion  43  such that a lens shape is formed. 
     Meanwhile,  FIG. 13  illustrates an example in which the light emitting device mounting portion  11  in which the light emitting device  20  is mounted is filled with a filling material  38  formed of a material such as a silicon gel, and a molding portion  43  including phosphors is formed. 
     At this point, the molding portion  43  can include a dispersing agent or a diffusing agent. 
       FIG. 14  illustrates an example in which a filling material  38  is formed on the light emitting device mounting portion  11 , and the filling material  38  is filled up to a portion higher than the package body  15 , and a lens-shaped molding portion  44  including phosphors is formed on the filling material  38 . 
     As described above, the molding portion  44  in the example illustrated in  FIG. 14  can be manufactured in a lens shape. 
     As described above, in forming a filling material and a lens-shape when a light emitting device package is manufactured, a separately manufactured lens can be attached and the lens shape can be manufactured using a dispensing method while a silicon gel or an epoxy resin is coated, so that a structure that can increase light emission efficiency without an additional process. 
     Therefore, the light emitting device package according to the embodiment can be applied particularly to a decorative lighting requiring high power and high efficiency, a general light, an electric part for an automobile, and a backlight for an LCD. 
     The embodiments are provided to explain in detail the spirit of the present disclosure, and the present disclosure is not limited to the embodiments. 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. 
     The light emitting device package according to the embodiments can be used as a light source of various electronic apparatuses as well as a lighting apparatus.