Abstract:
A light emitting diode includes a substrate consisting two separated parts with a gap therebetween. A first electrical connecting portion is fixed to one of the two separated parts of the substrate and adjacent to the gap. A second electrical connecting portion is fixed to the other one of the two separated parts of the substrate and adjacent to the gap. An LED chip is mounted on the substrate and electrically connected to the first and second electrical connecting portions. An encapsulation covers the LED chip and fills in at least a part of the gap to connect the two separated parts of the substrate together.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a divisional application of U.S. patent application Ser. No. 13/332,380, filed on Dec. 21, 2011, entitled “METHOD FOR MANUFACTURING LIGHT EMITTING DIODES INCLUDING FORMING CIRCUIT STRUCTURES WITH A CONNECTING SECTION”, assigned to the same assignee, and claiming foreign priority of China patent application No. 201110104678.0 filed on Apr. 26, 2011. The disclosures of the copending U.S. patent application and the China patent application are incorporated herein by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to a method for manufacturing semiconductor lighting devices, and particularly, to a method for manufacturing light emitting diodes. The present disclosure also relates to light emitting diodes obtained by the method. 
         [0004]    2. Description of Related Art 
         [0005]    Light emitting diodes (LEDs) have many beneficial characteristics, including low electrical power consumption, low heat generation, long lifetime, small volume, good impact resistance, fast response and excellent stability. 
         [0006]    In general, the LEDs are formed by dividing an LED wafer. The LED wafer includes a substrate, LED chips arranged on the substrate and an encapsulation covering the LED chips. An upper surface and a bottom surface of the substrate have metal electrodes formed thereon. In manufacture of the LEDs, the metal electrodes have to be etched to insulate from each other. In addition, a plurality of holes are defined in the substrate and filled with electrical conductive materials to electrically connect the metal electrodes on the upper surface and lower surface of the substrate. The process wastes a lot of time and the yielding rate of the LEDs is relatively low. 
         [0007]    What is needed is a method for manufacturing LEDs which can ameliorate the problems of the prior art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0009]      FIG. 1  is a flow chart of a method for manufacturing LEDs according to an exemplary embodiment of the present disclosure. 
           [0010]      FIG. 2  is a cross sectional view showing a semi-finished product obtained from a first step and a second step of the method in  FIG. 1 . 
           [0011]      FIGS. 3-4  are views similar to  FIG. 2 , showing the semi-finished product obtained after a third step of the method in  FIG. 1 . 
           [0012]      FIG. 5  is a view similar  FIG. 2 , showing the semi-finished product obtained after a fourth step of the method in  FIG. 1 . 
           [0013]      FIG. 6  is a view similar  FIG. 2 , showing the semi-finished product obtained after a fifth step of the method in  FIG. 1 . 
           [0014]      FIG. 7  is a view similar  FIG. 2 , showing the semi-finished product obtained after a sixth step of the method in  FIG. 1 . 
           [0015]      FIG. 8  is a view similar  FIG. 2 , showing an LED manufactured by the method in  FIG. 1 . 
           [0016]      FIG. 9  shows a top view of the LED of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    An embodiment of the present disclosure will now be described in detail below, with reference to the accompanying drawings. 
         [0018]      FIG. 1  shows a flow chart of a method for manufacturing an LED according to an exemplary embodiment of the present disclosure. The method for manufacturing the LED includes following steps: providing a substrate; forming a circuit structure on the substrate; cutting the circuit structure; fixing LED chips on the substrate; encapsulating the LED chips; and cutting the substrate. Details are given below. 
         [0019]    Referring to  FIG. 2 , firstly, the substrate  10  is provided. The substrate  10  can be made of a material selected from a group consisting of sapphire, ZnO, silicate, and ceramic. In this embodiment, the substrate  10  has a plurality of concaves respectively formed in an upper surface and a bottom surface thereof. The concaves are in a uniform interval. A plurality of through holes extends through the substrate  10 . Each through hole is aligned with and communicates with one concave in the upper surface (upper concave) and one concave in the bottom surface (bottom concave) of the substrate  10 . The through hole and corresponding upper concave and bottom concave cooperatively form a receiving space. 
         [0020]    Then, a plurality of circuit structures  20  are formed on the substrate  10  in a uniform interval. Each of the circuit structure  20  includes a first metal layer  21 , a second metal layer  22  and a connecting section  23  interconnecting the first metal layer  21  with the second metal layer  22 . The first metal layer  21  and the second metal layer  22  are arranged on the upper surface and the bottom surface of the substrate  10  respectively, and paralleled to and vertically aligned with each other. In this embodiment, each circuit structure  20  is filled on one receiving space, with the first metal layer  21  filled in the upper concave, the second metal layer  22  filled in the bottom concave, and the connecting section  23  filled in the through hole. An upper surface of the first metal layer  21  is coplanar with the upper surface of the substrate  10 , and a bottom surface of the second metal layer  22  is coplanar with the bottom surface of the substrate  10 . In this embodiment, the circuit structures  20  can be formed by insert molding technology. In an alternative embodiment, the circuit structures  20  can also be formed by sputtering, vacuum evaporating or electroplating. The circuit structure  20  can be made of a material selected from a group consisting of Al (aluminum), Cu (copper), and Ag (sliver). 
         [0021]    Then, referring to  FIGS. 3-4 , each of the circuit structures  20  is cut through along the connecting section  23 , thereto form a first electrical connecting portion  24  and a second electrical connecting portion  25  insulated from each other. In addition the substrate  10  is separated into a plurality of parts. The first electrical connecting portion  24  and the second electrical connecting portion  25  each extend from the upper surface to the bottom surface of the substrate  10 , thereto form a surface-mounting structure. A gap  26  is formed between adjacent first electrical connecting portion  24  and second electrical connecting portion  25 . In this embodiment, a width of the gap  26  is not less than 0.1 mm. In addition, in forming the circuit structures  20 , indentations (not shown) can previously be formed in the positions needed to be cut off. Cross sections of the indentations can be V-shaped, arch-shaped or square-shaped. 
         [0022]    Referring to  FIG. 5 , a plurality of LED chips  30  is formed on the substrate  10 , and particularly on the upper surfaces of the first electrical connecting portions  24 . The LED chips  30  can be made of a material selected from a group consisting of GaN, InGaN, AlInGaN, and GaP. Each LED chip  30  is secured to a corresponding first electrical connecting portion  24  by gluing of adhesive, and is electrically connected to the corresponding first electrical connecting portion  24  and second electrical connecting portion  25  by wire bonding of gold wires  40 . 
         [0023]    Referring to  FIG. 6 , then an encapsulation  50  is formed on the substrate  10  and encapsulating all of the LED chips  30  and the gold wires  40 . The encapsulation  50  is made of transparent materials such as epoxy resin, polycarbonate (PC) and polymethyl methacrylate (PMMA). The encapsulation  50  is doped with phosphors (not shown), thereto change the color of light emitted by the LED chip  30 . The phosphors can be made of garnets, silicates, nitrides or nitrogen oxides. The encapsulation  50  covers the upper surface of the substrate  10 , the upper surfaces of the first electrical connecting portions  24  and the upper surfaces of the second electrical connecting portions  25  and fills in the gaps  26 , thereto isolate the LED chips  30  from the external environment. The gaps  26  can be fully filled with the encapsulation  50 , or be partly filled with the encapsulation  50 , whereby the separated parts of the substrate  10  are connected together by the encapsulation  50 . 
         [0024]    Finally, referring to  FIG. 7 , the semi-finished product is severed along paths between the first electrical connecting portion  24  and the second electrical connecting portion  25  of neighboring circuit structures  20  through the substrate  10  and the encapsulation  50  in a direction perpendicular to the substrate  10 , thereto form a plurality of individual LEDs as shown in  FIGS. 8-9 . 
         [0025]    As described above, the method for manufacturing the LEDs includes a step of forming circuit structure  20  on the substrate  10 . The circuit structure  20  includes the first metal layer  21  formed on the upper surface of the substrate  10 , the second metal surface  22  formed on the bottom surface of the substrate  10  and the connecting section  23  extending through the substrate  10  and connecting the first metal layer  21  with the second metal layer  22 . Then the circuit structure  20  is cut through along a middle of the connecting section  23  in a direction particular to the substrate  10 , thereto form the first electrical connecting portion  24  and the second electrical connecting portion  25  insulated from each other. A gap  26  is formed between adjacent first electrical connecting portion  24  and second electrical connecting portion  25 . LED chips  30  are adhered to the first electrical connecting portions  24 , respectively, and electrically connected to the first and second electrical connecting portions  24  by wire bonding. Encapsulation  50  is applied on the upper surface of the substrate  10  to encapsulate the LED chips  30  and fill in the gaps  26  to obtain a semi-finished product. Finally, the semi-finished product is severed along paths between the first electrical connecting portions  24  and the second electrical connecting portions  25  between neighboring circuit structures  20  through the encapsulation  50  and the substrate  10  in a direction particular to the substrate  10  to obtain the LEDs. The method for manufacturing the LEDs described above is simple and easy to operate. Thus, the yielding rate of the LEDs is high. 
         [0026]    While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The disclosure is not limited to the particular embodiments described and exemplified, and the embodiments are capable of considerable variation and modification without departure from the scope and spirit of the appended claims.