Abstract:
A method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring is disclosed, in which a slot space is defined by two optical glasses and a partition frame having a partition ring on the inner wall surface. The partition frame is installed with two slots diametrically opposite to each other, and the slot space is evacuated to allow filling of a fluorescent material, and then the two slots are sealed so that the moisture is prevented from permeating into the fluorescent layer, and thus the optical performance can be maintained over a long period.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates a method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring, and especially to a method of completely sealing a fluorescent layer in a slot space defined by two optical glasses and a fastening frame, so that the moisture is prevented from permeating into the fluorescent layer, and thus the optical performance can be maintained over a long period, and the method of the present invention can be applied to a light emitting diode (LED) array package. 
     2. The Prior Arts 
     An LED is a solid-state semiconductor device, which operates based on the recombination of carriers (electrons and holes) in a semiconductor. When an electron in the conduction band combines with a hole in the valence band, it loses energy equal to the bandgap of the semiconductor in the form of an emitted photon, i.e., light. The LED has advantages of compact volume, fast start-up time and high efficiency so that it has been applied to various fields. 
     Referring to  FIG. 1 , which is a cross sectional view showing a conventional array-type LED package structure, which includes a substrate  10   a , a package module  12   a , a lead frame  14   a , and a packaging cover  16   a . The substrate  10   a  is installed at the bottom of the package structure. The package module  12   a  is served to integrate the substrate  10   a  and the lead frame  14   a . The LED dices  18   a  are arranged on the substrate  10   a  in an array form, and the substrate  10   a  is made of a metal material. The LED dices  18   a  are electrically connected to the lead frame  14   a . The packaging cover  16   a  is closely engaged with the package module  12   a . An insulating protective layer  20   a  is formed on the LED dices  18   a  for covering the LED dices  18   a . Then, a fluorescent layer  22   a  is formed on the insulating protective layer  20   a.    
     However, one disadvantage of the prior art is that the fluorescent layer of the LED dice is directly in contact with moisture in the air. It is known that a fluorescent material can absorb moisture and would result in the deterioration of light property, and an initially white light would gradually decays while changing its hue. Moreover, the fluorescent layer can directly absorb heat generated by light irradiation. In general, the heat resistant temperature and thermal stability of a fluorescent layer are relatively low, and thereby once heat generated by light irradiation is conducted to the fluorescent layer, the fluorescent material would deteriorate and the illumination efficiency is affected and the chromaticity is altered. 
     Moreover, if a fluorescent material is formed on an LED chip by filling or coating, an extra amount of the fluorescent material has to be provided for ensuring that the fluorescent material will form substantially uniformly on a LED chip, which will increase the manufacturing cost. Moreover, if the fluorescent layer has flaws, the LED chip can not be recycled and reused. In a conventional method, various optical tests can only be carried out after the formation of the fluorescent layer. Therefore, there is a need to provide an LED package structure which can be optically tested in advance, has relatively low manufacturing cost, and has excellent heat dissipation. 
     SUMMARY OF THE INVENTION 
     The objective of the present invention is to provide a method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring. A partition frame is firstly provided. An inwardly protruding partition ring is arranged on the inner wall surface of the partition frame. An L-shaped structure is defined by a top surface of the partition ring and the inner wall surface of the partition frame, and a reverse L-shaped structure is defined by a bottom surface of the partition ring and the inner wall surface of the partition frame, wherein the partition ring of the partition frame is installed with at least two slots. A top optical glass and a bottom optical glass are respectively installed on the top surface and on the bottom surface of the partition ring. The top optical glass and the surface of the L-shaped structure, and the bottom optical glass and the surface of the reverse L-shaped structure are all integrally adhered and sealed together, so that a slot space is defined by the top optical glass, the bottom optical glass, and the partition ring of the partition frame. The top optical glass, the bottom optical glass, and the partition frame adhered and sealed together are put in a vacuum chamber. The slot space is evacuated through the at least two slots, and then a fluorescent material is filled in the slot space so as to form a fluorescent layer. An adhesive is used to seal the at least two slots, or a nail member coated with an adhesive is used to seal the two slots. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which: 
         FIG. 1  is a cross sectional view showing a conventional LED package structure; 
         FIG. 2  is a schematic view showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention; 
         FIG. 3  is a schematic view showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention; 
         FIG. 4  is a schematic view showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention; 
         FIG. 5  is a schematic view showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention; 
         FIG. 6  is a schematic view showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention; 
         FIG. 7  is a schematic view showing the partition frame according to the first embodiment of the present invention; 
         FIG. 8  is a schematic view showing the partition frame according to the second embodiment of the present invention; 
         FIG. 9  is a schematic view showing the partition frame according to the third embodiment of the present invention; 
         FIG. 10  is a schematic view showing the top optical glass according to one embodiment of the present invention; 
         FIG. 11  is a schematic view showing a product made by the present invention being applied in an array-type LED according to one embodiment of the present invention; and 
         FIG. 12  is a schematic view showing a product made by the present invention being applied in an array-type LED according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     Referring to  FIGS. 2-6 , which are schematic views showing the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring according to the present invention. As shown in  FIG. 2 , a partition frame  1  is provided, and an inwardly protruding partition ring  11  is arranged on the inner wall surface of the partition frame  1 . The inwardly protruding partition ring  11  has a top surface  111  and a bottom surface  113 . An L-shaped structure is defined by the top surface  111  of the partition ring  11  and the inner wall surface of the partition frame  1 . A reverse L-shaped structure is defined by the bottom surface  113  of the partition ring  11  and the inner wall surface of the partition frame  1 . At least two slots  115  are located in the partition ring  11  diametrically opposite to each other. 
     The two slots  115  diametrically opposite to each other can be the through-holes installed in the partition ring  11 , or the two slots  115  can be formed on the surfaces of the L-shaped structures. Referring to  FIG. 7 , one opening end of each of the two slots  115  is arranged on the inner surface of the partition ring  1 , and the other opening end of each of the two slots  115  is arranged on the top surface of the partition frame  1 . The two slots  115  can also be the through-holes installed in the partition frame  1 . However, the arrangement and the quantities of the slots  115  depend on the actual needs. The two slots disclosed in this embodiment are served for illustration and shall not be a limitation to the scope of the present invention, and any slot arrangement which can communicate the interior and exterior of the partition frame  1  is within the scope of the present invention. 
     The material of the partition frame  1  includes at least one of glass, aluminum, bronze, ceramic and an alloy composed of at least one of aluminum and bronze, or includes at least one of liquid crystal polymer (LCP), polyphthalamide (PPA), and all high temperature resistant materials. The shape of the partition frame  1  includes round, oval, rectangular and polygonal shapes. 
     A top optical glass  3  and a bottom optical glass  5  are respectively installed on the top surface  111  and the bottom surface  113  of the partition ring  11 . The top optical glass  3  and the surface of the L-shaped structure and the bottom optical glass  5  and the surface of the reverse L-shaped structure are integrally adhered and sealed, such that a slot space  6  is defined by the top optical glass  3 , the bottom optical glass  5  and the partition ring  11  of the partition frame  1 , as shown in  FIG. 3 . 
     After being assembled, the top optical glass  3 , the bottom optical glass  5  and the partition frame  1  are together disposed in a vacuum chamber  7 , as shown in  FIG. 4 . The slot space  6  is evacuated with a vacuum pump through the at least two slots  115 , meanwhile the slot space  6  is filled with a fluorescent material, so as to form a fluorescent layer  8  in the slot space  6 , as shown in  FIG. 5 . 
     As shown in  FIG. 6 , the adhesive  9  is used to seal the at least two slots  115 , then the adhesive  9  is filled into the slot space, so that the fluorescent layer  8  is prevented from leaking while being in a liquid state, or a nail member (not shown) coated with the adhesive  9  can be used to seal the at least two slots  115 . The adhesive  9  includes at least one of ultraviolet curing adhesive, silicon, epoxy resin and polyimide, and the material of the nail member includes at least one of plastic and metal. 
     Referring to  FIG. 8 , which is a schematic view showing the partition frame according to the second embodiment of the present invention. The two slots  115  are respectively installed on the surface of the partition ring  11  diametrically opposite to each other. The top optical glass  3  is formed with two grooves  31  diametrically opposite to each other, and the two grooves  31  can communicate with the two slots  115 , so that the adhesive  9  can be filled in the two slots and the two grooves. 
     Referring to  FIG. 9 , which is a schematic view showing the partition frame according to the third embodiment of the present invention. The partition ring  11  of the partition frame  1  is made of ultraviolet curing adhesive, silicon, epoxy resin, or polyimide. 
     Referring to  FIG. 10 , which is a schematic view showing the top optical glass according to one embodiment of the present invention. In  FIG. 3  to  FIG. 6 , the top optical glass  3  or the bottom optical glass  5  can be a flat lens, and the top optical glass  3  can also be a convex lens of which the top surface is convex for obtaining different optical guiding effects. 
     Referring to  FIG. 11 , which is a schematic view showing an array-type LED made by the method of the present invention according to one embodiment of the present invention. Referring to  FIG. 12 , which is a schematic view showing an array-type LED made by the method of the present invention according to another embodiment of the present invention. An array-type LED includes a substrate  100  and a package module  200 . The substrate  100  is disposed at the bottom of the array-type LED and is installed with a plurality of light emitting units  300 . The light emitting units  300  are arranged on the substrate  100  in an array form. The light emitting units  300  are electrically connected to two lead frames  400  installed in the package module  200  by wire bonding. A dice protective layer  500  and a silicon layer  600  are sequentially formed on top of the light emitting units  300 . The package module  200  is installed with a fastening frame slot  210  corresponding to the location of the partition frame  1  so that the partition frame  1  can be assembled with the package module  200 . Therefore, the method of filling and sealing a fluorescent layer in a slot space defined by two optical lenses and a partition ring can be applied to an LED array package. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.