Abstract:
The present invention discloses a high-efficiency light-focusing package structure for a solar chip, which includes: a solar-chip sustaining substrate, a pair of positive-electrode and negative-electrode lead frames, and a covering. The covering may focus sunlight and also has an anti-reflective function to promote sunlight absorption. Further, the package structure for a solar chip of the present invention is low-cost and can be designed and assembled according to the size and shape required by a user.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a light-focusing package structure for a solar chip, particularly to a package structure for a solar chip, which may be assembled in to an array of arbitrary shape.  
         [0003]     2. Description of the Related Art  
         [0004]     A solar cell utilizes photovoltaic effect to convert solar energy into electric energy. Refer to  FIG. 1  for the structure of a conventional solar cell. The conventional solar cell  105  has an N-type-semiconductor layer  110 , a P-type-semiconductor layer  112 , an anti-reflective layer, and two electrodes  114  and  116 . When photons enter into the solar cell  105 , there are electrons-holes generated and diffusing across the junction between the N-type-semiconductor layer  110  and the P-type-semiconductor layer  112 . Thus, a current is generated from the top electrode  114  and the bottom electrode  116 . Generally, the solar energy absorbed by the solar cell  105  may be raised by increasing the light-receiving area or utilizing a light-focusing device, such as a lens structure. However, a large-area light-focusing element is hard to fabricate, and an arbitrary-size assemblage of solar cells is also hard to accomplish. Besides, the yield thereof is also hard to promote, and the cost thereof is thus raised. Therefore, developing an easy-fabrication and easy-assemblage light-focusing package structure for a solar chip is also one of the important subjects in the fields concerned.  
       SUMMARY OF THE INVENTION  
       [0005]     One of objects of the present invention is to provide a light-focusing package structure for a solar chip, which may be fabricated with LED fabrication process to simply the packaging process of a light-focusing solar cell.  
         [0006]     Another one of objects of the present invention is to provide a package structure for a solar chip. The LED lead frame and epoxy encapsulation structure are used to package a solar chip in order to simplify the packaging process of a solar chip and implement the size-adjustability of a solar-cell assemblage.  
         [0007]     To achieve the abovementioned objects, an embodiment of the present invention proposes a high-efficiency light-focusing package structure for a solar chip, which includes: a solar chip; a substrate supporting the solar chip; multitudes of wiring connection structures electrically coupled to the solar chip; and an covering encapsulating the solar chip, the substrate, and a portion of the wiring connection structures. Furthermore, the covering may focus sunlight and has an anti-reflective function to increase sunlight absorption.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a diagram schematically showing the structure of a conventional solar cell.  
         [0009]      FIG. 2A  and  FIG. 2B  are diagrams schematically showing the package structure for a solar chip according to a first embodiment of the present invention.  
         [0010]      FIG. 3A  and  FIG. 3B  are diagrams schematically showing the package structure for a solar chip according to a second embodiment of the present invention.  
         [0011]      FIG. 4A  and  FIG. 4B  are diagrams schematically showing the package structure for a solar chip according to a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     Refer to  FIG. 2A  a diagram schematically showing the package structure for a solar chip according to a first embodiment of the present invention. The dual In-line solar-chip package structure  10  includes: a solar chip  12 , a substrate  14 , multitudes of wiring connection structures  16 , and a covering  18 . In this embodiment, the substrate  14  is used to sustain or support the solar chip  12  and made of an electrically-conductive metal, such as copper or iron. The solar chip  12  may be a mono-crystalline-silicon solar chip, a polycrystalline-silicon solar chip, an amorphous-silicon solar chip, or a gallium arsenide solar chip. The solar chip  12  is affixed onto the surface of the substrate  14  via an appropriate method, such as via an adhesive layer (not shown in the drawing). However, in the present invention, the affixing method is not limited to using an adhesive layer. The solar chip  12  includes: at least one N-type-semiconductor layer, at least one P-type-semiconductor layer, an absorptive layer, and two electrodes. Those two electrodes are respectively electrically coupled to different wiring connection structures  16 . In this embodiment, the positive electrode and the negative electrode are separately disposed at different sides of the solar chip  12 , but, in another embodiment of the present invention, the positive electrode and the negative electrode may be disposed at same side of the solar chip  12 , as shown in  FIG. 2B . It is understood that the structure of the solar chip  12  is not limited to that mentioned above but may further include other structures, such as a glass substrate and a barrier layer. Inner leads  13  and  19  are respectively used to electrically connect the electrodes to external leads  15  and  11 . The external leads  11  and  15  are configured to attach and electrically couple to an external structure (not shown in the drawing) and may also be used as power leads. The external leads  11  and  15  may be disposed at appropriate positions of the solar-chip package structure  10 , such as the lateral side or the bottom of the solar chip  12 . However, the present invention does not limit the external-lead position to those mentioned above.  
         [0013]     The covering  18 , such as an epoxy body, covers and protects the solar chip  12  and the inner leads  13  and  19 , and may focus sunlight. In another embodiment, the covering  18  may also function as an anti-reflective layer and let more sunlight enter into the dual In-line solar-chip package structure  10 . Due to the characteristic of its material, the covering  18  may be fabricated into various geometrical shapes to focus the sunlight from various directions. Thus, the dual In-line solar-chip package structure  10  may receive the sunlight coming from every direction even it is still at a fixed position. Therefore, the present invention may solve the problem that the solar panel consisting of assembled solar chips has to modify its orientation to follow the sun&#39;s track to increase incident sunlight. Besides, the dual In-line solar-chip package structure  10  can be fabricated with a common LED packaging process without any extra mold and machine. Further, the dual In-line solar-chip package structures  10  may be assembled in the same method as LED uses. Thus, the dual In-line solar-chip package structures  10  may be assembled into a solar-energy system of a desired size and geometry.  
         [0014]     Refer to  FIG. 3A  and  FIG. 3B  diagrams schematically showing the package structure for a solar chip according to a second embodiment of the present invention. Similar to the dual In-line solar-chip package structure  10 , the SMD (Surface Mount Device) solar-chip package structure  20  includes: a solar chip  12 , a substrate  14 , multitudes of wiring connection structures  16 , and a covering. Different wiring connection structures  16  are respectively connected to the positive electrode and the negative electrode, which are simultaneously disposed at same side of the solar chip  12  or separately disposed at different sides of the solar chip  12 . Dissimilar to the dual In-line solar-chip package structure  10 , the SMD solar-chip package structure  20  has external leads  11  and  15  extending from the lateral sides of the solar chip  12 . Therefore, the SMD solar-chip package structure  20  has a flattened geometry. Thus, the contact points of the external leads  11  and  15  may be affixed to an external element via an SMT method. Besides, the covering of the SMD solar-chip package structure  20  may be made of an anti-reflective transparent material to increase incident sunlight.  
         [0015]     Refer to  FIG. 4A  and  FIG. 4B  diagrams schematically showing the package structure for a solar chip according to a third embodiment of the present invention. The TO (Transistor Outline)-Cans solar-chip package structure  30  includes: a solar chip  12 , a TO header  14 , a TO body  18 . In this embodiment, the solar chip  12  is affixed to the TO header  14  and electrically coupled to the inner lead  13  and the contact  17  on the TO header  14 . The inner lead  13  and the contact  17  may penetrate the TO header  14  and extend outward to function as external leads  15  and  11 . The TO body  18  may protect the solar chip  12  and focus the sunlight coming from all directions, and the TO body  18  may be made of an anti-reflective material so that more sunlight may penetrate the TO body  18 . The shape of the TO body  18  is not limited to be the column shape shown  FIG. 4A  and  FIG. 4B  but may further include all shapes having light-focusing effect. Besides, what is installed on the TO header  14  is not limited to one or multitudes solar chips  12  but may also include chips and elements of other functions.  
         [0016]     Those embodiments described above are to clarify the technical thoughts and characteristics of the present invention in order to enable the persons skilled in the art to understand, make and use the present invention. However, it is not intended to limit the scope of the present invention, and any equivalent modification and variation according to the spirit of the present invention is to be also included within the scope of the claims of the present invention.