Abstract:
Provided are a light emitting device package and a lighting device. The light emitting device package includes a base, a light emitting device on the base, a plurality of electrode pads on the base, the plurality of electrode pads electrically connected to the light emitting device, a frame disposed on the base, wherein a size of the frame is smaller than a size of the base, a silver layer on a portion of the plurality of electrode pads, the silver layer directly contacted with the frame and an optical member covering the light emitting device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/792,589, filed Jun. 2, 2010 (now U.S. Pat. No. 8,044,423 issued on Oct. 25, 2011), which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/146,292, filed Jun. 25, 2008 (now U.S. Pat. No. 7,755,099 issued on Jul. 13, 2010) and claims priority under 35 U.S.C. 119 Korean Patent Application No. 10-2007-0063771, filed on Jun. 27, 2007, each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     A light emitting diode (LED) is a semiconductor device that can be realized as various light emitting sources using compound semiconductor materials such as GaAs, AlGaAs, GaN, InGaN, and AlGaInP. 
     The characteristics of the LED can be determined by a material, color, brightness, and the range of brightness intensity of a compound semiconductor. Also, the LED is packaged and is applied to various fields such as a lighted-on display representing color, a character display, and an image display. 
     SUMMARY 
     Embodiments provide a light emitting device package that attaches a silicon wafer on a metal substrate and allows a light emitting device to be mounted through an opening of the wafer, and a manufacturing method thereof. 
     Embodiments provide a light emitting device package that can cover the outer periphery of a light emitting device with a reflective frame formed of silicon, and a manufacturing method thereof. 
     An embodiment provides a light emitting device package comprising: a base; a light emitting device on the base; a plurality of electrode pads on the base, the plurality of electrode pads electrically connected to the light emitting device; a frame disposed on the base, wherein a size of the frame is smaller than a size of the base; a silver layer on a portion of the plurality of electrode pads, the silver layer directly contacted with the frame; and an optical member covering the light emitting device. 
     An embodiment provides a lighting device comprising: a base; a light emitting device on the base; a plurality of electrode pads on the base, the plurality of electrode pads electrically connected to the light emitting device; a frame disposed on the base, wherein a size of the frame is smaller than a size of the base; a reflecting layer on a portion of the plurality of electrode pads, the silver layer directly contacted with the frame; and an optical member covering the light emitting device. 
     An embodiment provides a lighting device comprising: a base; a light emitting device on the base; a plurality of electrode pads on the base, the plurality of electrode pads electrically connected to the light emitting device; and a frame disposed on the base, wherein a size of an upper surface of the base is larger than a size of the frame, and a portion of at least one of the plurality of electrode pads formed outside is emerged through a bottom of the frame and is parallel to the base. 
     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 
         FIG. 1  is a plan view of a light emitting device package according to an embodiment. 
         FIG. 2  is a side cross-sectional view of  FIG. 1 . 
         FIGS. 3 to 6  are views illustrating a method for manufacturing a light emitting device package. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. 
       FIG. 1  is a plan view of a light emitting device package according to an embodiment. 
     Referring to  FIGS. 1 and 2 , a light emitting device package  100  comprises a silicon frame  101 A, a base substrate  111 , electrode pads  113  and  115 , and a light emitting diode  121 . 
     The silicon frame  101 A can comprise silicon and silicon carbide (SiC). When silicon is used, the frame can have a thinner thickness than that of ceramic frame. Also, the silicon frame is not deformed depending on temperature and time. That is, the silicon frame  101 A has no shape deformation or color change at high temperature compared to a polyphthalamide (PPA) resin. 
     Referring to  FIG. 2 , the silicon frame  101 A is attached on the base substrate  111 . Here, an adhesive  119  is used between the silicon frame  101 A and the base substrate  111 . The adhesive  119  can comprise Ag paste or a polymer resin material such as epoxy. 
     An opening is formed in the silicon frame  101 A. The opening  103  is a portion in which the light emitting diode  121  is disposed. The surface of the opening can be formed in a circular shape or a polygonal shape. 
     A lateral side  105  is formed around the opening  103 . The lateral side is formed to be inclined by 91-160° to the outer direction with respect to the bottom to efficiently reflect incident light. Metal material having high light reflectivity, such as Ag and Al can be formed on the lateral side  105 . 
     The base substrate  111  can comprise a substrate formed of metal such as aluminum oxide, copper, and tungsten having high thermal conductivity. 
     An insulating layer  112  can be formed on the base substrate  111 . The insulating layer  112  can be selected from a resin material, SiO 2 , Si 3 N 4 , Al 2 O 3 , and TiO 2 . 
     The plurality of electrode pads  113  and  115  are formed in a land shape on the insulating layer  112 . The plurality of electrode pads  113  and  115  are electrically open inside the opening  103  and exposed to both sides of the silicon frame  101 A. In the case where a via hole (not shown) is formed in the base substrate  111 , the plurality of electrode pads  113  and  115  can be electrically connected to the lower portion of the base substrate  111  through the via hole. 
     The light emitting device  121  is attached on at least one of the electrode pads  113  and  115  disposed in the opening  103  and electrically connected to the other electrode  115  using a wire  122 . Here, in the case where the light emitting device  121  is a vertical semiconductor light emitting device, it can be attached on the electrode pad  113  using a conductive adhesive. In the case where the light emitting device  121  is a lateral semiconductor light emitting device, it can be connected to respective electrode pads using a plurality of wires. Also, the light emitting device  121  can be connected to the respective electrode pads  113  and  115  using a flip method. There is no limitation in the chip structure of the light emitting device  121 , and a mounting method. 
     Also, at least one light emitting device  121  can be disposed in the opening  103 . A color LED chip such as a blue LED chip, a green LED chip, a red LED chip, and a yellow LED chip, and an ultraviolet (UV) LED chip can be selectively mounted as the light emitting device  103 . Here, the light emitting device  121  can be a compound semiconductor formed of a material such as GaAs, AlGaAs, GaN, InGaN, and AlGaInP. 
     A resin material  123  such as a transparent epoxy and silicon can be used as a molding in the opening  103  where the light emitting device  121  is disposed. Fluorescent material can be added to the resin material  123 . For example, in the case where target light is white light for lighting or indication and the light emitting device  121  emits blue light, yellow fluorescent material can be added to the resin material  123 . The yellow fluorescent material comprises but are not limited to YAG or yellow fluorescent material for silicate. A lens can be attached on the resin material. 
     The light emitting device package  100  is a chip-on-board (COB) type package, and has excellent heatsink performance and excellent light efficiency, so that it can be provided for use in a power package of 3 W or more. 
       FIGS. 3 to 6  are views illustrating a method for manufacturing a light emitting device package. 
       FIG. 3  is a plan view illustrating the silicon frame of  FIG. 1 . 
     Referring to  FIG. 3 , the silicon wafer  101  is the silicon frame of  FIG. 2 , and can comprise a material such as silicon and silicon carbide (SiC). When silicon is used, the frame can have a thinner thickness (ex: minimum thickness of 150 μm) than that of ceramic frame. Also, the silicon frame is not deformed depending on temperature and time. 
     The silicon wafer  101  is a nonconductor of electricity having electrical conductivity of 10 10  Ωcm or more, and can be formed of a material having high thermal conductivity of 140 W/mK or more. 
     The silicon wafer  101  comprises openings  103  and package boundary holes  107 . The openings  103  are separated with a constant interval and arranged in a matrix configuration. The opening  103  can have a circular or polygonal surface, which can be formed through a semiconductor etching process. 
     The lateral side  105  of the opening  103  is inclined by a predetermined angle (ex: 90-160° C.) to the outer side with respect the bottom. Metal material (ex: Ag and Al) having high light reflectivity can be deposited on the lateral side  105 . 
     Also, the package boundary holes  107  can be formed with a constant interval along the vertical direction and/or horizontal direction of the silicon wafer  101 , and can change depending on the dicing direction of a unit package. The package boundary hole  107  separates the openings  103  to the left and right. 
       FIG. 4  is a plan view illustrating the base substrate of  FIG. 1 . 
     Referring to  FIG. 4 , the base substrate  111  can comprise a metal substrate formed of a material such as aluminum oxide, copper, and tungsten. The insulating layer  112  is formed on the base substrate  111 . A pair of electrode pads  113  and  115  are formed on the insulating layer  112 . 
     The pair of electrode pads  113  and  115  are open, respectively, to correspond to the openings  103  (of  FIG. 2 ), and are realized in a land pattern. The electrode pads  113  and  115  are formed with a constant interval from the left to the right direction. One of the electrodes  113  and  115  is formed in a larger size to allow a light emitting device to be disposed thereon. 
       FIG. 5  is an exploded perspective view of a silicon wafer disposed on a base substrate, and  FIG. 6  is a side cross-sectional view illustrating a light emitting device is mounted after a silicon wafer is attached on a base substrate. 
     Referring to  FIG. 5 , the silicon wafer  101  is disposed in the upper portion, and the base substrate  111  is disposed in the lower portion, and then they are aligned such that the openings  103  are disposed on the plurality of electrode pads  113  and  115 . Also, the package boundary hole  107  is disposed between the electrode pads  113  and  115  forming a pair. 
     Referring to  FIGS. 5 and 6 , an adhesive  119  is coated on the electrode pads  113  and  115  of the base substrate  111 . The adhesive  119  can comprise an Ag adhesive material or a polymer resin material such as epoxy. The lower surface of the silicon wafer  101  is attached on the base substrate  111 . At this point, the bottom of the opening  103  is disposed such that the pair of electrode pads  113  and  115  are electrically open. 
     The light emitting device  121  is attached on one of the electrode pads  113  and  115  of the base substrate  111  disposed in the opening  103  using a conductive adhesive, and connected to the other pad  115  using a wire  122 . Here, the light emitting device  121  comprises but is not limited to an LED chip manufactured using a compound semiconductor formed of GaAs, AlGaAs, GaN, InGaN, and AlGaInP. Also, the light emitting device  121  can comprise one or more LED chips, for example, or one or more red/green/blue LED chips for a lighting purpose. The light emitting device  121  can be mounted on the electrode pads  113  and  115  using a wire or flip bonding, and is not limited thereto. 
     Also, at least one light emitting device  121  can be disposed in the opening  103  and is not limited thereto. 
     The light emitting device  121  is mounted on the base substrate  111  in a COB type, so that it has excellent heatsink performance and excellent light efficiency. Accordingly, the light emitting device  121  can be provided for use in a power package of 3 W or more. 
     The resin material  123  is formed in the opening  103 . At this point, the resin material  123  comprises a transparent silicon or epoxy. YAG or yellow fluorescent material for silicate can be added to the resin material. For example, yellow fluorescent material can be added to the resin material  123  to excite blue light into yellow light and emit the same. 
     After that, the silicon wafer  101  is diced in respective package units T 1  using the package boundary holes  107 , so that individual LED package  100  can be obtained as illustrated in  FIGS. 1 and 2 . 
     Since an outer frame formed of silicon is used for the LED package, a thinner package can be manufactured in comparison with using a ceramic material. Also, since the outer frame formed of silicon is used, limitations by a shape and color can be complemented and thus reliability of the package improves. 
     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. 
     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.