Abstract:
A method of manufacturing an LED package including steps: providing an electrode, the electrode including a first electrode, a second electrode, a channel defined between the first electrode and the second electrode, the first electrode and the second electrode arranged with intervals mutually, a cavity arranged on the first electrode, and the cavity communicating with the channel; arranging an LED chip electrically connecting with the first electrode and the second electrode and arranged inside the cavity; providing a shield covering the first electrode and the second electrode; injecting a transparent insulating material to the cavity via the channel, and the first electrode, the second electrode, and the shield being interconnected by the transparent insulating material; solidifying the transparent insulating material to obtain the LED package.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a divisional application of patent application Ser. No. 13/326,340, filed on Dec. 15, 2011, entitled “LED PACKAGE AND METHOD FOR MANUFACTURING THE SAME,” which is assigned to the same assignee as the present application, and which is based on and claims priority from Chinese Patent Application No. 201110083148.2 filed in China on Apr. 2, 2011. The disclosures of patent application Ser. No. 13/326,340 and the Chinese Patent Application are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The disclosure relates to a method for manufacturing light emitting diode (LED) package, wherein the LED package has a good heat dissipation and a high luminous efficacy. 
         [0004]    2. Description of the Related Art 
         [0005]    The many advantages of light emitting diodes (LEDs), such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, easy driving, long term reliability, and environmental friendliness have promoted their wide use as a light source. Now, light emitting diodes are commonly applied in environmental lighting. However, an encapsulation layer must be formed on the substrate during the manufacture of a common LED package structure. The common LED package structure does not have good thermal dissipation efficiency. Thus, the reliability and luminous efficacy of the common LED package will decrease. 
         [0006]    Therefore, it is desirable to provide a method for manufacturing LED package which can overcome the described limitations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the disclosure can be better understood with reference to the drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present LED package. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views. 
           [0008]      FIG. 1  is a cross sectional view of an LED package in accordance with a first embodiment. 
           [0009]      FIG. 2  is a top view of the LED package of  FIG. 1 . 
           [0010]      FIG. 3  is a cross sectional view of an LED package in accordance with a second embodiment. 
           [0011]      FIG. 4  is a cross sectional view of an LED package in accordance with a third embodiment. 
           [0012]      FIG. 5  is a top view of the LED package of  FIG. 4 . 
           [0013]      FIG. 6  is a process flow for manufacturing the LED package of  FIGS. 1-2 . 
           [0014]      FIG. 7  is a cross sectional view of the LED package in accordance with the third embodiment and a mold for manufacturing the LED package. 
           [0015]      FIG. 8  is a cross sectional view of an LED package in accordance with a fourth embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Embodiments of an LED package and a method for manufacturing the LED package as disclosed are described in detail here with reference to the drawings. 
         [0017]    Referring to  FIGS. 1 and 2 , an LED package structure  100  includes an electrode  10 , a connection electrode  20 , an LED chip  30 , a lens  40 , and an insulation layer  50 . 
         [0018]    The electrode  10  includes a first electrode  11  and a second electrode  12 . The first electrode  11  and the second electrode  12  are arranged with intervals mutually. A channel  13  is formed between the first electrode  11  and the second electrode  12 . The first electrode  11  and the second electrode  12  are rectangular. 
         [0019]    The mass of the first electrode  11  exceeds that of the second electrode  12 . The first electrode  11  has a top surface  112 , and a cavity  111  is defined on the top surface  112 . The LED chip  30  is arranged inside the cavity  111 . Thus, the LED chip  30  is attached to the bottom surface of the cavity  111 . The bottom surface of the cavity  111  is a dished or curved surface. In this embodiment, the bottom surface of the cavity  111  is dished. The depth of the cavity  111  exceeds the thickness of the LED chip  30 . Thus, the LED chip  30  is totally within the cavity  111 . A reflection layer  114  is formed on the inside surface of the cavity  111 . The material of the electrode  10  is copper, and the material of the reflection layer  114  is silver. 
         [0020]    The connection electrode  20  includes a first connection electrode  21  and a second connection electrode  22 . The first connection electrode  21  is a strip of electrically conductive material. The first connection electrode  21  includes a fixture end  211  and a free end  212 . The fixture end  211  connects with the top surface  112  of the first electrode  11 . The free end  212  extends to the top of the cavity  111 . The second connection electrode  22  is also a strip of electrically conductive material. 
         [0021]    The second connection electrode  22  includes a fixture end  221  and a free end  222 . The fixture end  221  connects to the top surface of the second electrode  12 . The free end  222  extends to the top of the cavity  111 . A certain distance exists between the free end  212  of the first connection electrode  21  and the free end  222  of the second connection electrode  22 . The top surfaces of the first connection electrode  21  and the second connection electrode  22  are at the same horizontal level. A gap  23  is between the top surface  112  of the first electrode  11  and the second connection electrode  22 . The gap  23  communicates with the channel  13  and the cavity  111 . The material of the connection electrode  20  is the same as that of the electrode  10 . 
         [0022]    In another embodiment, the first electrode  11  and the first connection electrode  21  are formed in one piece. Furthermore, the second electrode  12  and the second connection electrode  22  may be formed in one piece. 
         [0023]    The LED chip  30  is arranged in the cavity  111  of the first electrode  11 . The LED chip  30  is attached at the bottom of the cavity  111 . The LED chip  30  has two electrodes (not shown). A welding spot  31  is arranged on each of the two electrodes. The welding spots  31  connect to the free ends  212  of the first connection electrode  21  and the free end  222  of the second connection electrode  22 . Thus, the LED chip  30  connects electrically to the first electrode  11  and to the second electrode  12 . 
         [0024]    The lens  40  is transparent. The lens  40  includes a light incident surface  41  near the LED lens  40 , a light emitting surface  42  away the LED chip  30 , and a side surface  43  connecting to the light incident surface  41  and the light emitting surface  42 . The light incident surface  41  is flat. The light incident surface  41  is attached to the first connection electrode  21  and the second connection electrode  22 . 
         [0025]    A space  44  exists between the light incident surface  41  and the top surface  112  of the first electrode  11 . The first light emitting surface  42  has at least one protrusion portion  421 . The protrusion portion  421  extends in a direction away the LED chip  30 . In another embodiment, the quantity and shape of the protrusion portion  421  can be changed according to specific needs. The side surface  43  is coplanar with the side surface defined by the first electrode  11  and the second electrode  12 . Thus, the lens  40  totally covers the first electrode  11  and the second electrode  12 . The lens  40  is made of silicon resin, epoxy resin, and silicon oxide. 
         [0026]    The insulation layer  50  fills the channel  13  between the lens  40 , the first electrode  11 , and the second electrode  12 . Furthermore, the insulation layer  50  also totally fills the surround of the LED chip  30  in the cavity  111  and the space  44  between the lens  40  and the electrode  10 . The insulation layer  50  is made by the injection method. Moreover, a plurality of fluorescent powders is uniformly added to the insulation layer  50 . Thus, the light emitting characteristics of the LED package structure  100  are enhanced. 
         [0027]      FIG. 3  shows an LED package structure  200  of a second embodiment. The only difference from the first embodiment is that a cavity  111   a  defined at the top surface  112  of the first electrode  11  has an opening facing the second electrode  12 . The cavity  111   a  communicates with to the channel  13   a  via the opening of the cavity  111   a.  In another embodiment, another cavity  121  (as shown in  FIG. 8 ) is defined at the second electrode  12 . The opening of the other cavity  121  of the second electrode  12  faces the first electrode  11 . 
         [0028]    Referring to  FIGS. 4 and 5 , an LED package  300  of a third embodiment includes an electrode  10 , a connection electrode  20 , an LED chip  30 , and an encapsulating layer  60 . 
         [0029]    The electrode  10 , the connection electrode  20 , and the LED chip  30  in the third embodiment are the same as in the first embodiment. The only differences from the first embodiment is that the encapsulating layer  60  includes an insulation layer  61  which fills the surrounding of the LED chip  30  and covers the connection electrode  20 , and a lens  62  on the insulation layer  61 . 
         [0030]    The insulation layer  61  and the lens  62  are formed in one piece. The insulation layer  61  fills the channel  13  defined by the first electrode  11  and the second electrode  12 . The lens  62  includes a light emitting surface  621  away the LED chip  30 . A protrusion portion  622  is formed on the light emitting surface  621  of the lens  62 . The insulation layer  61  connects around the edge of the light emitting surface  621 . A cover  63  extends from the edge of the light emitting surface  621  towards the electrode  10 . The cover  63  encapsulating the side wall of the electrode  10  has a bottom which is coplanar with the bottom of the electrode  10  away the LED chip  30 . 
         [0031]    The encapsulating layer  60  maintains a firm connection with the electrode  10  because of the formation of the cover  63 . 
         [0032]      FIG. 6  shows the process flow of the LED package  100  in the first embodiment. The electrode  10  including the first electrode  11 , and the second electrode  13 , the channel  13  defined by the first electrode  11  and the second electrode  12  are to be provided. A cavity  111  is defined on the first electrode  11 . The cavity  111  communicates with the cavity  13 . 
         [0033]    The LED chip  30  is arranged inside the cavity  111 . The LED chip  30  connects electrically to the first electrode  11  and the second electrode  12 . 
         [0034]    A shield covering the first electrode  11  and the second electrode  12  is to be provided. 
         [0035]    Inject a transparent insulating material(s) into the cavity  111  from the channel  13  by the injection method. The transparent insulating materials totally interconnect the first electrode  11 , the second electrode  12 , and the shield. 
         [0036]    When transparent insulating material(s) solidify, the package is formed. 
         [0037]    The shield can be the lens  40  in the first embodiment. The LED chip  30  connects with the electrode  10  by means of the connection electrode  20 . The connection electrode  20  includes the first connection electrode  21  and the second connection electrode  22 . The connection electrode  20  is pre-coated on the light incident surface  41  of the lens  40 . Then, the electrode  10  is attached on the lens  40 , and the LED chip  30  connects to the first connection electrode  21  and to the second connection electrode  22  by means of die bonding. 
         [0038]    In another embodiment, the connection electrode  20  and the electrode  10  are formed in one piece out of one piece of electrically conductive material. The LED chip  30  is connected to the connection electrode  20  by die bonding. Then, the lens  40  is attached on the electrode  10 . 
         [0039]    During the injection method, the transparent insulating material is injected into the channel  13  defined between the first electrode  11  and the second electrode  12  until the transparent insulating material totally fills the cavity  111  and the space  44  between the lens  40  and the electrode  10 . The insulation layer  50  is formed when the transparent insulating material solidifies. An amount of fluorescent powder(s) is added into the transparent insulating material before the injection process. Thus, the fluorescent powders will be uniformly mixed into the insulation layer  50  on solidification. 
         [0040]    Referring to  FIG. 7 , the shield can be a mold  70 . The mold  70  includes a receiving cavity  71  and a concave portion  72 . The size of the receiving cavity  71  exceeds the encircling size of the first electrode  11  and the second electrode  12 . 
         [0041]    Thus, the first electrode  11  and the second electrode  12  are fixed within the receiving cavity  71 . Then, during the injection method, the transparent insulating material is injected into the channel  13  defined between the first electrode  11  and the second electrode  12  until the mold  71  is totally filled. The transparent insulating material in the concave portion  72  forms the protrusion portion  622  of the lens  62  of  FIG. 4 . 
         [0042]    Thus, the transparent insulating material in the mold  70  becomes the encapsulating layer  60  in the third embodiment. 
         [0043]    The transparent material may be directly injected into the channel  13  defined between the first electrode  11  and the second electrode  12 . Thus, the packaged structure is completed. The packaging method is simple. The LED chip  30  is arranged inside the cavity  111 . The first electrode is a substrate carrying the LED chip  30 . The electrode  10  being made of metal results in good electrical and thermal conductivity by the first electrode  11 . Thus, any heat generated by the LED chip  30  can be efficiently dissipated via the first electrode  11 . The thermal dissipation efficiency of the LED package structure and the brightness of the LED product are increased. 
         [0044]    While the disclosure has been described by way of example and in terms of exemplary embodiments, it is to be understood that the disclosure is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.