Abstract:
A light emitting element package includes a package substrate, at least one light emitting element, a first encapsulation layer and a second encapsulation layer. The at least one light emitting element is mounted on the package substrate. The first encapsulation layer is mounted on the package substrate for encapsulation the at least one light emitting element. The second encapsulation layer is configured for encapsulation a back side of the at least one light emitting element.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The disclosure relates generally to semiconductor packages, and more particularly to a light emitting element package and fabrication method for the package. 
         [0003]    2. Description of the Related Art 
         [0004]    Often thicknesses of metal electrodes mounted on LED chips are not uniform. When the LED chips are bonded to a substrate, poor solder joins are often formed between the metal electrodes and the substrate. 
         [0005]    Therefore, what is needed is a LED package that can alleviate the limitations described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the embodiments can be better understood with references 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 embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout two views. 
           [0007]      FIGS. 1-10  are schematic views of a fabrication method for a light emitting element package in accordance with one embodiment of the disclosure. 
           [0008]      FIG. 11  is a cross-section of a light emitting element package in accordance with one embodiment of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
         [0010]    A method for light emitting element package is as follows. 
         [0011]    Referring to  FIG. 1 , a temporary substrate  10  is provided. The temporary substrate  10  can be Al 2 O 3 , SiC, LiAlO 2 , LiGaO 2 , Si, GaN, ZnO, AlZnO, GaAs, GaP, GaSb, InP, InAs or ZnSe. 
         [0012]    Referring to  FIG. 2 , a semiconductor unit  11  is formed on the temporary substrate  10 . The semiconductor unit  11  can be formed by chemical vapor deposition (CVD), metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). The semiconductor unit  11  can be group III-V elements or group II-VI elements. In the embodiment, the semiconductor unit  11  includes a p-type semiconductive layer  111 , a light emitting layer  112  and an n-type semiconductive layer  113 . The light emitting layer  112  is single layer hetero structure, double heterostructure, single quantum well or multiple quantum well structure. 
         [0013]    Referring to  FIG. 3 , a plurality of light emitting elements  110  is formed on the semiconductor unit  11  by photolithography or lithography. Each of the light emitting elements  110  further includes a first electrode  114  and a second electrode  115 . Each first electrode  114  is electrically coupled to the p-type semiconductive layer  111 . Each second electrode  115  is electrically coupled to the n-type semiconductive layer  113 . The first electrodes  114  and the second electrodes  115  are Ni, Cr, Au, Ag, Pt, Cu, Zn, Ti, Si or a combination thereof. The first electrodes  114  and the second electrodes  115  are formed by evaporation, sputtering or etching. 
         [0014]    Referring to  FIG. 4 , a plurality of first protrusions  12   a  is formed on the first electrodes  114 . A plurality of second protrusions  12   b  is formed on the second electrodes  115 . The first protrusions  12   a  and the second protrusions  12   b  are Ni, Sn, Cr, Cu, Au, Ag, Pb, Pt, Zn, Ti, Si or a combination thereof. The first protrusions  12   a  and the second protrusions  12   b  are formed by stencil printing. 
         [0015]    Referring to  FIG. 5 , a first encapsulation layer  13  is formed on the temporary substrate  10  to encapsulate the light emitting elements  110 . The first encapsulation layer  13  is epoxy, silicone or a combination thereof. The first encapsulation layer  13  is formed by transfer molding, spin coating, or injection molding. 
         [0016]    Referring to  FIG. 6 , a smooth surface  131  of the encapsulation layer  13  is obtained by grinding using grinding equipment  100 . The first protrusions  12   a  and the second protrusions  12   b  can protrude from the surface  131 . 
         [0017]    Referring to  FIG. 7A , a package substrate  14  is mounted on the surface  131  of the first encapsulation layer  13 . The package substrate  14  is a circuit module  141 . The circuit module  141  is a plurality of first circuits  141   a  and a plurality of second circuits  141   b . Each first circuit  141   a  is electrically connected to each second circuit  141   b.    
         [0018]    The first electrodes  114  and the second electrodes  115  are electrically coupled to the second circuits  141   b  through the first protrusions  12   a , the second protrusions  12   b  and the first circuits  141   a . The package substrate  14  can be plastic, polymer, ceramic, silicon, metal, or a combination thereof. The circuit module  141  is made of conductive materials, such as Cu, Ni, Au, Ag or a combination thereof. 
         [0019]    Referring to  FIG. 7B , the package substrate  14  is mounted on the surface  131  by an adhesive layer  20  of anisotropic conductive material. The adhesive layer  20  can be a film, a gel or a paste. The adhesive layer  20  is formed on the surface  131  by thermal transfer printing. The anisotropic conductive material is conductive in direction perpendicular to the surface  131  and nonconductive parallel thereto. 
         [0020]    Referring to  FIG. 8 , the temporary substrate  10  is removed by lifting, etching, cutting, or grinding. 
         [0021]    Referring to  FIG. 9A , a second encapsulation layer  15  is formed on the downward surface of the light emitting elements  110 . The second encapsulation layer  15  and the first encapsulation layer  13  are not coplanar. The second encapsulation layer  15  is opposite to the first encapsulation layer  13 . The second encapsulation layer  15  is epoxy, silicone or a combination thereof. 
         [0022]    The second encapsulation layer  15  further is a phosphor element  151 . The phosphor element  151  is YAG, TAG, silicate, nitride, nitrogen oxide, phosphide, sulfide or a combination thereof. 
         [0023]    The phosphor element  151  can be regularly distributed in the second encapsulation layer  14 . 
         [0024]    Referring to  FIG. 9B , the phosphor element  152  is a patch. The phosphor element  151 ,  152  can also be a film or a lumiramic plate, not limited to the shape disclosed. The phosphor elements  151 ,  152  are formed by coating, paste, or spray. 
         [0025]    Referring to  FIG. 10 , a plurality of light emitting element packages  1  is diced by lifting. The semiconductor unit  11  is lifted along the scribe lines  16  to form the light emitting element packages  1 . 
         [0026]    Referring to  FIG. 11 , each light emitting element package  1  is the circuit module  141  defined in the package substrate  14 , light emitting element  110 , first encapsulation layer  13 , phosphor element  152  and the second encapsulation layer  15 . The number of light emitting elements defined in one light emitting element package  1  can exceed two. The first circuit  141   a  is electrically coupled to the second circuit  141   b  through conductive traces  17  defined in the package substrate  14 . 
         [0027]    While the disclosure has been described by way of example and in terms of exemplary embodiment, it is to be understood that the disclosure is not limited thereto. To 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.