Patent Publication Number: US-2015060912-A1

Title: Light emitting diode package having zener diode covered by reflective material

Description:
BACKGROUND 
       1 . Technical Field 
     This disclosure generally relates to light sources, and particularly to a light emitting diode (LED) package which has a zener diode covered by reflective material. 
       2 . Description of Related Art 
     A typical light emitting diode package includes a substrate, a first electrode formed on the substrate, a second electrode formed on the substrate, a light emitting diode located on the substrate and electrically connecting with the first electrode and the second electrode respectively, and a zener diode located on a plane the same as the light emitting diode to protect the light emitting diode from damage caused by current surge or electrostatic discharge. However, a portion of light emitted from the light emitting diode is absorbed by the zener diode, which decreases the lighting efficiency and the brightness of the light emitting diode package. 
     What is needed, therefore, is a light emitting diode package and a method for manufacturing the light emitting diode package which can overcome the forgoing drawbacks. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a light emitting diode package in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a side view of the light emitting diode package of  FIG. 1 . 
         FIGS. 3-8  show steps of manufacturing the light emitting diode package of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-2 , an exemplary light emitting diode package  100  of the present disclosure is provided. 
     The light emitting diode package  100  includes a substrate  10 , a light emitting diode  20  located on the substrate  10 , a zener diode  30  located on the substrate  10 , and an encapsulation layer  40  covering the light emitting diode  20  and the zener diode  30 . The light emitting diode  20  is spaced from the zener diode  30 . The light emitting diode  20  and the zener diode  30  are mounted on a top surface of the substrate  10 , and spaced from each other by a distance. 
     The substrate  10  has a rectangular configuration. The substrate  10  includes a first electrode  11 , a second electrode  12 , and an insulation layer  13  sandwiched by the first electrode  11  and the second electrode  12 . The first electrode  11  is spaced from the second electrode  12 . The insulation layer  13  fills into a gap between the first and second electrodes  11 ,  12 , and contacts with the first electrode  11  and the second electrode  12  respectively. The insulation layer  13  electrically insulates the first electrode  11  from the second electrode  12 . In this embodiment, the first electrode is a P-type electrode, and the second electrode  12  is an N-type electrode. 
     The light emitting diode  20  is formed on the first electrode  11 , and electrically connects with the first and second electrodes  11 ,  12  respectively via conducting wires. The zener diode  30  is formed on the second electrode  12  and electrically connects with the first by a conductive wire and the second electrode  12  by a direct bonding. In this embodiment, the light emitting diode  20  and the zener diode  30  are located at a same side of the substrate  10 . 
     A reflecting layer  50  is formed on the zener diode  30 . Preferably, the reflecting layer  50  covers the entire zener diode  30  therein. The reflecting layer  50  reflects light striking the reflecting layer  50 . The reflecting layer  50  is formed on the zener diode  30  by means of a glue dispensing process. The reflecting layer  50  is made of opaque materials. In this embodiment, the reflecting layer  50  contains reflective particles, such as TiO 2  or SiO 2  particles in silicone glue. 
     The encapsulation layer  40  is formed on the substrate  10 , and covers the light emitting diode  10 , the zener diode  30  and the reflecting layer  50  therein. The encapsulation layer  40  is transparent. The encapsulation layer  40  is made of transparent materials, such as silicone or epoxy resin. Preferably, the encapsulation layer  40  contains fluorescent powders therein, such as garnet fluorescent powders, silicate fluorescent powders, nitride fluorescent powders, nitride oxide fluorescent powders, phosphide fluorescent powders, sulfide fluorescent powders, or a combination thereof. The fluorescent powders can help the LED package  100  to emit light with the required color, for example, white. 
     According to the exemplary light emitting diode package  100  of the present disclosure, because a reflecting layer  50  is formed on the zener diode  30 , light emitted from the light emitting diode  20  and striking the reflecting layer  50  is reflected by the reflecting layer  50  to radiate out of the light emitting diode package  100 , rather than is absorbed by the zener diode  30 , whereby lighting efficiency and light brightness of the light emitting diode package  100  is increased. 
     The present disclosure also relates to a method for manufacturing the light emitting diode package  100 , and the method includes following steps: 
     S 1 : referring to  FIGS. 3-4 , a substrate  10  is provided. The substrate  10  includes the first electrode  11 , the second electrode  12  and the insulation layer  13  electrically insulating the first electrode  11  from the second electrode  12 . 
     S 2 : referring to  FIGS. 5-6 , the light emitting diode  20  is mounted on the first electrode  11  of the substrate  10 , and electrically connected to the first and second electrodes  11 ,  12 . 
     S 3 : the zener diode  30  is mounted on the second electrode  12 , and electrically connected to the first and second electrodes  11 ,  12 . 
     S 4 : referring to  FIGS. 7-8 , the reflecting layer  50  is formed on the zener diode  30 . In this embodiment, the reflecting layer  50  is formed by means of a glue dispensing process, and the reflecting layer  50  covers the entire zener diode  30  therein. 
     S 5 : referring to  FIGS. 1-2 , the encapsulation layer  40  is formed on the substrate  10  to cover the light emitting diode  20 , the zener diode  30  and the reflecting layer  50  therein to form the light emitting diode package  100 . 
     It is to be understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments without departing from the spirit of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure.