Abstract:
A semiconductor light emitting device package including a main body including a supporting member and an outside member on the supporting member; at least one semiconductor light emitting device disposed on the supporting member in which the outside member at least partially surrounds the at least one semiconductor light emitting device; first and second electrodes, at least one electrode of the first and second electrodes at least partially extending under the at least one semiconductor light emitting device; a metallic member disposed under the at least one semiconductor light emitting device and extending beyond outside edges of the at least one semiconductor light emitting device; a first molding part surrounded by the outside member and covering the at least one semiconductor light emitting device; and a second molding part disposed on the first molding part, the second molding part formed in a domed shape.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
     This application is a continuation application of Ser. No. 12/443,659 filed on Mar. 30, 2009 now U.S. Pat. No. 8,158,996, and claims priority to Korean application No. 10-2006-0134414 filed on Dec. 27, 2006, the entire contents of which are incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The embodiment relates to a semiconductor light emitting device package. 
     DISCUSSION OF THE BACKGROUND ART 
     A semiconductor light emitting device package comprises an LED light emitting diode), an LD (laser diode) and the like. A semiconductor light emitting device is used to convert electrical signals into infrared rays, visible rays and the like by using the characteristics of a compound semiconductor and to exchange the converted signals In general, an LED has been widely used for household electrical appliances, remote controllers, electric light boards, indicators, and various automation devices, and is largely clarified as an IRED (infrared emitting diode) and a VLED (visible light emitting diode). 
     In general, an LED having a small size is fabricated in the form of a surface mount device so that the LED is directly mounted on a PCB (printed circuit board). Accordingly, an LED lamp used as a display device is also fabricated in the form of a surface mount device. Such a surface mount device can replace an existing simple lighting lamp and is used as a lighting indicator producing various colors, a character indicator, an image indicator and the like. 
     As described above, such a semiconductor light emitting device package has been used for various fields, for example, electric lights for daily life, electric lights for outputting rescue signals and the like. Further, demand for a high-brightness semiconductor light emitting device has increased more and more. Thus, a high-power light emitting device package capable of improving the heat dissipation and light emitting efficiency has been actively developed. 
     SUMMARY OF THE INVENTION 
     The embodiment provides a semiconductor light emitting device package capable of improving the heat dissipation and light emitting efficiency by forming a single package using at least one high-power semiconductor light emitting device. 
     A semiconductor light emitting device package according to an embodiment comprising: a package body comprising a groove section; an electrode in the groove section; at least one semiconductor light emitting device electrically connected to the electrode in the groove section of the package body; an interconnection pattern on an outer peripheral surface of the package body and electrically connected to the electrode, wherein a part of the interconnection pattern is on a bottom surface of the package body; and a metal pattern is on the bottom surface of the package body corresponding to an area in which the semiconductor light emitting device is located. 
     A semiconductor light emitting device package according to an embodiment comprising: a heat conductive package body comprising a groove section; a electrode in the groove section; at least one semiconductor light emitting device electrically connected to the electrode in the groove section of the package body; an interconnection pattern on an outer peripheral surface of the package body and electrically connected to the electrode; a substrate supporting the package body; and a land pattern on the substrate. 
     According to the semiconductor light emitting device of the embodiment, heat radiating and light emitting efficiency is improved, so that a high brightness and high heating type semiconductor light emitting device, such as a light emitting device for illumination, can be easily prepared in the form of a single package regardless of the number of semiconductor light emitting devices. 
     According to the embodiment, the structure of the electrodes (comprising the interconnection pattern) is improved, so that heat dissipation can be easily performed, and a circuit construction of a plurality of semiconductor light emitting devices can be simplified. 
     According to the embodiment, the molding area having a superior optical function and the molding area having a superior protective function are individually formed, and are differentially molded by forming the groove section, so that the two molding areas can be firmly manufactured and the optical characteristics can be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side sectional view showing the structure of a semiconductor light emitting device package according to an embodiment; 
         FIG. 2  is a perspective view schematically showing the structure of a semiconductor light emitting device package according to an embodiment; 
         FIG. 3  is a bottom view schematically showing the structure of a semiconductor light emitting device package according to an embodiment; 
         FIG. 4  is a side sectional view showing a part of a package body constituting a semiconductor light emitting device package according to an embodiment; and 
         FIG. 5  is a side sectional view showing paths through which heat is radiated on a semiconductor light emitting device package according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the description of an embodiment, it will be understood that, when a layer (or film), a region, a pattern, or a structure is referred to as being “on” or “under” another substrate, another layer (or film), another region, another pad, or another pattern, it can be “directly” or “indirectly” on the other substrate, layer (or film), region, pad, or pattern, or one or more intervening layers may also be present. 
     Hereinafter, an embodiment will be described with reference to the accompanying drawings. 
       FIG. 1  is a side sectional view showing a semiconductor light emitting device package according to an embodiment. 
     As shown in  FIG. 1 , the semiconductor light emitting device package  100  according to the embodiment comprises a substrate  110 , an insulator  115 , a land pattern  120 , a solder part  125 , an interconnection pattern  130 , an electrode  132 , a reflective layer  135 , a semiconductor light emitting device  140 , a first molding part  145 , a second molding part  150  and a package body  160 . 
     The semiconductor light emitting device package  100  according to the embodiment achieves the high light efficiency and high heat radiating (heat conductive) efficiency as a light emitting device package for illumination. 
     The semiconductor light emitting device package  100  according to the embodiment may be divided into a first structure based on the package body  160  and a second structure based on the substrate  110 . 
     The semiconductor light emitting device package  100  according to the embodiment may also comprise only the first structure or a combination of the first structure and the second structure. 
     The first structure comprises the package body  160 , the interconnection pattern  130 , the electrode  132 , the reflective layer  135 , the semiconductor light emitting device  140 , the first molding part  145  and the second molding part  150 . The second structure comprises the substrate  110 , the insulator  115 , the land pattern  120  and the solder part  125 . The land pattern  120 , for example, denotes an electrode pad formed for contact with an external device on a PCB (printed circuit board). 
     According to the embodiment, processes of mounting the first structure including the package body  160  on the substrate  110 , and cutting and breaking the substrate  110  are performed, so that the semiconductor light emitting device package having a combination structure of the first structure and the second structure can be manufactured. 
     Hereinafter, the construction and operation of the semiconductor light emitting device package according to the embodiment will be described with reference to the accompanying drawings. 
       FIG. 2  is a perspective view schematically showing the structure of the semiconductor light emitting device package according to the embodiment, and  FIG. 1  is a side sectional view showing the section  1 - 1  of the semiconductor light emitting device package shown in  FIG. 2 . 
     Referring to  FIGS. 1 and 2 , the package body  160  serves as a housing, and has a groove section  155  at the central portion thereof. The semiconductor light emitting device  140  is located in the groove section  155 . 
     The package body  160  may be formed of materials (or combinations of materials) having superior insulating properties and heat conductivity such as silicon, SiC (silicon carbide), AlN (aluminum nitride) and the like. Preferably, the package body  160  may be subject to surface treating by using SiOx (silicon oxide) or SiNx (silicon nitride) under the conditions in which the electrical conductivity is 10 10  Ω/cm or more and the heat conductivity is 140 W/mK or more. 
     The package body  160  has a hexahedral shape including four sides inclined in upward and downward directions When the package body  160  comprises silicon, each side has an inclination angle of about 109°, e.g., 107° to 111°. 
     As the sides of the package body  160  are inclined as described above, when the solder part  125  is formed by soldering or reflowing, the solder part  125  can be coated on parts of the sides and upper surfaces of the package body  160 . Thus, an additional heat dissipation path can be formed through the solder part  125  together with the interconnection pattern  130 . Simultaneously, the package body  160  is drawn toward the substrate  110  to form a short heat dissipation path, so that heat dissipation can be easily achieved. 
     The groove section  155  is etched in a rectangular shape similarly to the shape of the package body  160 , and four sides thereof are inclined from the top to the bottom (i.e. the groove section  155  can be prepared in the form of a truncated square pyramid shape). 
     The reason for upwardly inclining the sides of the groove section  155  is to emit light in the upward direction by reflecting the light generated from the semiconductor light emitting device  140  (the reflective layer  135  is located at the groove section  155 ). The reflective layer  135  comprises material, such as silver, aluminum and the like, which has a reflectivity of 90% or more within the range of a visible ray. 
     When the side of the groove section  155  comprises silicon, an inclination angle between the side and the bottom surface thereof is about 125°, i.e., 123° to 127°. This denotes an angle formed when the crystal surface &lt;100&gt; of semiconductor silicon is etched. 
     The groove section  155  has a depth relatively shorter than the length and width thereof, and the length may have the same numerical value as that of the width. For example, the groove section  155  may have a depth corresponding to at least ½ of the length of the package body  160 . The depth is 150 μm or more. 
     Meanwhile, the electrodes  132  are formed at the inner surface of the groove section  155  to be electrically connected to the semiconductor light emitting device  140 . Further, the electrodes  132  are connected to the interconnection pattern  130  at the outer portion of the groove section  155 . The interconnection pattern  130  extends along the upper and bottom surfaces of the package body  160  to be electrically connected to the land pattern  120  of the substrate  110 . 
     The electrode  132  comprises the same conductive material as that of the interconnection pattern  130 . The electrode  132  and the interconnection pattern  130  may be provided as a single structure or may be separated from each other. The electrode  132  and the interconnection pattern  130  have sufficient thickness in consideration of the amount of electric current and current density applied thereto. 
     The interconnection pattern  130  is curved several times from the upper surface of the package body  160 , except for the groove section  155 , to the bottom surface of the package body  160  along the outer surface of the package body  160 . The interconnection pattern  130  formed along the upper and outer surfaces of the package body  160  serves as an electrical path and radiates heat, which is transferred to the package body  160 , to an exterior of the package body  160 . 
     Further, the interconnection pattern  130  formed along the bottom surface of the package body  160  is electrically connected to the land pattern  120  of the substrate  110  through the solder part  125 . The interconnection pattern  130  can physically adhere to the substrate  110 . 
     The interconnection pattern  130  may have the same curved structure on the four sides of the package body  160 . At this time, it is advantageous in terms of heat dissipation if the interconnection pattern  130  and the electrode  132  are designed to have a large area on the package body  160 . 
     The electrodes  132  may be individually formed on the bottom surface and the four sides in the groove section  155 . 
       FIG. 3  is a bottom view schematically showing the structure of the semiconductor light emitting device package according to the embodiment. 
       FIG. 3  shows the bottom surface of the package body  160  other than the bottom surface of the substrate  110 . Referring to  FIG. 3 , the interconnection pattern  130  extends up to the bottom surface of the package body  160  while being curved along the four sides of the package body  160 . Further, a metal pattern  130   a  is formed at the lower center portion of the package body  160 . 
     The metal pattern  130   a  is located corresponding to the groove section  155  to which the semiconductor light emitting device  140  is disposed, and can be connected to the land pattern  120  of the substrate  110  through the solder part  125 . 
     The metal pattern  130   a  connected to the land pattern  120  of the substrate  110  transmits the heat of the package body  160  to the substrate  110  through the shortest path to maximize the heat dissipation. 
       FIGS. 2 and 3  shows a case in which a single semiconductor light emitting device (chip type) is provided. However, a plurality of semiconductor light emitting devices may also be provided to be connected to the electrodes  132 , respectively. The semiconductor light emitting device according to the embodiment can be coupled to the electrodes  132  through flip chip bonding or wire bonding. 
     The semiconductor light emitting device  140  may comprise III-V group compound such as GaN, AlN, InN, GaAs and the like. 
     The substrate  110  comprises heat conductive material such as aluminum or copper, and radiates the heat, which is transferred from the interconnection pattern  130 , to the lower portion of the substrate  110 . The land pattern  120  formed on the surface of the substrate  110  is connected to the interconnection pattern  130  through the solder part  125 . 
     That is, the substrate  110  and the package body  160  can be physically fixed to each other through the solder part  125 . 
     The insulator  115  is formed between the substrate  110  and the land pattern  120 , so that the land pattern  120  can be electrically insulated from the substrate  110 . 
       FIG. 4  is a side sectional view showing a part of the package body constituting the semiconductor light emitting device package according to the embodiment.  FIG. 4  is an enlarged view of “A” shown in  FIG. 1  when the semiconductor light emitting device package according to the embodiment is manufactured. 
     As shown in  FIGS. 1 and 4 , the reflective layer  135  is formed on the electrodes  132  in the groove section  155  to reflect the light, which is emitted from the semiconductor light emitting device  140 , in the upward direction toward the semiconductor light emitting device  140 . Further, the reflective layer  135  may be formed on a part of the upper surface of the package body  160 , except for the groove section  155 , corresponding to the area in which the second molding part  150  is formed. 
     Referring to  FIG. 1 , the interconnection pattern  130 , the electrodes  132  and the reflective layer  135 , which comprise metal, and the first molding part  145  comprising transmissive resin is disposed on the package body  160  comprising silicon. 
     The first molding part  145  is formed in the groove section  155  and is provided as light transmissive protective resin. For example, the first molding part  145  can seal the groove section  155  by using silicon or epoxy comprising fluorescent material. 
     The reference light generated from the semiconductor light emitting device  140  is emitted in the upward direction. 
     In the vicinity of the surface of the semiconductor light emitting device  140 , the reference light is absorbed in the fluorescent material of the first molding part  145  and then is re-emitted as excited light (that is, excited secondary light). Thus, a white color may be displayed due to mixture of the excited light and the reference light. 
     In such a case, since color variation and difference of uniformity occur according to the shape of the first molding part  145  comprising the fluorescent material, the first molding part  145  preferably has a flat shape with respect to the opened surface of the groove section  155 . 
     As described above, the first molding part  145  is thinly formed on the semiconductor light emitting device  140  without extending out of the groove section  155 , so that a light path of the emitting light and reflecting light from the semiconductor light emitting device  140  to the first molding part  145  can be uniformly formed. 
     The first molding part  145  primarily seals the groove section  155  and the second molding part  150  secondarily seals the groove section  155 . At this time, the second molding part  150  has a dome shape. When the light generated from the semiconductor light emitting device  140  is emitted to the air, a proper interfacial angle is set between the second molding part  150  and the air such that the light can be efficiently emitted from the interface between the second molding part  150  and the air without total reflection. Further, the second molding part  150  guides an optical path such that the light can be uniformly emitted in an upward direction. 
     Further, the semiconductor light emitting device package  100  according to the embodiment may comprise an ESD protective device, such as a Schottky diode or a Zener diode, in order to protect the semiconductor light emitting device  140  when an ESD (electrostatic discharge) phenomenon or over-voltage occurs. 
     The ESD protective device may be formed at the package body  160 . According to one example, the ESD protective device may be located on the upper surface of the package body  160 , in which the groove section is not formed, instead of the groove section. At this time, the ESD protective device can be prepared in the form of a protective circuit, which is electrically connected to the interconnection pattern  130  and the electrodes  132 , which are formed along the package body  160 , in parallel to the semiconductor light emitting device  140  to protect the semiconductor light emitting device  140 . 
       FIG. 5  is a side sectional view showing paths through which heat is radiated on the semiconductor light emitting device package according to the embodiment. 
     Referring to  FIG. 5 , the heat radiated from the semiconductor light emitting device  140  is transferred to the substrate  110  through the paths via the electrodes  132 , the interconnection pattern  130 , the solder part  125  and the land pattern  120 . Accordingly, the heat transfer paths are expanded, so that a light emitting device emitting a large amount of heat, such as a semiconductor light emitting device for illumination, can efficiently dissipate heat. 
     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 included 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 drawing; 
     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. 
     According to the semiconductor light emitting device of the embodiment, heat radiating and light emitting efficiency is improved, so that a high brightness and high heating type semiconductor light emitting device, such as a light emitting device for illumination, can be easily prepared in the form of a single package regardless of the number of semiconductor light emitting devices. 
     According to the embodiment, the structure of the electrodes (comprising the interconnection pattern) is improved, so that heat dissipation can be easily performed, and a circuit construction of a plurality of semiconductor light emitting devices can be simplified 
     According to the embodiment, the molding area having a superior optical function and the molding area having a superior protective function are individually formed, and are differentially molded by forming the groove section, so that the two molding areas can be firmly manufactured and the optical characteristics can be improved.