Abstract:
A method for manufacturing an LED (light emitting diode) package comprises following steps: providing an electrically insulated base, the base having a first surface and a second surface opposite thereto; an annular voltage stabilizing module is formed on the first surface; a first electrode is formed on the first surface, wherein the first electrode is attached to and encircled by the voltage stabilizing module; a second electrode is formed on the first surface, wherein the second electrode is attached to and encircles the voltage stabilizing module; an LED chip is mounted on the first electrode, wherein the LED chip is electrically connected to the first and second electrodes, and the LED chip and the voltage stabilizing module are connected in reverse parallel. Finally, an encapsulative layer is brought to encapsulate the LED chip.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a divisional application of patent application Ser. No. 13/533,981, filed on Jun. 27, 2012, entitled “LIGHT EMITTING DIODE PACKAGE HAVING A VOLTAGE STABILIZING MODULE CONSISTING OF TWO DOPING LAYERS”, assigned to the same assignee, which is based on and claims priority from China Patent Application No. 201110190981.7, filed in China on Jul. 8, 2011, and disclosures of both related applications are incorporated herein by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to semiconductor devices and, more particularly, to a light emitting diode (LED) package and a method for manufacturing the LED. 
         [0004]    2. Description of the Related Art 
         [0005]    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. These characteristics have enabled the LEDs to be widely used as a light source in electrical appliances and electronic devices. 
         [0006]    The LEDs are one-way conducting elements. If current flows through the LEDs in a forward direction, the LEDs emit light. If current flows through the LEDs in a reverse direction, the LEDs fail to emit light. In addition, the LEDs would be broken down if the reverse current is too large. There is unpredictable current, such that caused by static electricity, which may flow through the LEDs in the reverse direction during the operation of the LEDs. A voltage stabilizing diode such as a Zener diode, is therefore applied to the LEDs for preventing the LEDs from damage by such unpredictable current in the reverse direction. A typical design of the Zener diode is reverse parallel connecting the Zener diode with the LEDs via wires and positioning the Zener diode outside of the package of the LEDs. The reverse parallel connection means that the Zener diode is connected in parallel with LEDs while the Zener diode is reverse biased and the LEDs are forward biased. Such design has some deficiencies. For example, such a connection way results in a complicated structure, and a large volume of the LEDs. More importantly, such a connection way may not obtain a stable electrical connection between the Zener diode and the LEDs after the LEDs having been use for a certain time. 
         [0007]    What is needed is an LED package and a method for manufacturing the LED package which can overcome the problem of the prior art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a section view of an LED package in accordance with an exemplary embodiment of the present disclosure. 
           [0009]      FIG. 2  is a top view of the LED package in accordance with the exemplary embodiment of the present disclosure. 
           [0010]      FIG. 3  shows a plurality of structures being made according to a flow chart of a method of manufacturing the LED package in accordance with the exemplary embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Referring to  FIGS. 1 and 2 , a light emitting diode (LED) package in accordance with an exemplary embodiment of the present disclosure comprises an electrically insulated base  100 , two LED chips  11 , a voltage stabilizing module  12 , a first electrode  131 , a second electrode  132 , and an encapsulative layer  14 . The voltage stabilizing module  12  is formed on the base  100  and electrically connects to the first and second electrodes  131 ,  132 . The LED chips  11  are mounted on the first electrode  131  and electrically connect to the first and second electrodes  131 ,  132 . When the first and second electrodes  131 ,  132  electrically connect to a power source (not shown), the LED chips  11  have forward current flowing therethrough and emit light. The voltage stabilizing module  12  has a polarity arranged opposite to that of each of the LED chips  11 . Thus, the irregular current or static electricity, if there is any during the operation of the LED chips  11 , can be discharged by the voltage stabilizing module  12 , and the LED chips  11  are prevented from damage. In the preferred embodiment, the first electrode  131  is connected to the positive pole of the power source, while the second electrode  132  is connected to the negative pole of the power source, whereby the forward current can flow through the LED chips  11  to cause the LED chips  11  to emit light. 
         [0012]    Specifically, the base  100  has a first surface  101  and a second surface  102  opposite to the first surface  101 . A protrusion  103  extends upwardly and annularly from the first surface  101 . The protrusion  103  can be formed by patternizing the first surface  101  via microlithography and etching. The base  100  may be made of the following one or more than one of the materials: Si, GaAs, ZnO and InP. 
         [0013]    The voltage stabilizing module  12  can be formed by doping the protrusion  103  of the base  100  to convert the protrusion  103  into the voltage stabilizing module  12 . The doping can by any type such as epitaxial dope, diffusing dope or ion-implantation. It is understood that the voltage stabilizing module  12  can be formed on the surface of the protrusion  103 . The voltage stabilizing module  12  comprises a first doping layer  121  and a second doping layer  122 . The first doping layer  121  is located beside the second doping layer  122 . The first doping layer  121  and the second doping layer  122  have an identical thickness, and are in the same level. The first doping layer  121  is a P-type doping layer, and the second doping layer  122  is an N-type doping layer. 
         [0014]    The first electrode  131  is positioned on a center portion of the first surface  101  of the base  100 . The first electrode  131  has a rectangular shape. The first electrode  131  is encircled by the voltage stabilizing module  12 . Specifically, the second doping layer  122  encircles and is attached to the first electrode  131 , and the first doping layer  121  encircles and is attached to the second doping layer  122 . The second electrode  132  encircles and is attached to the first doping layer  121 . 
         [0015]    The voltage stabilizing module  12  is such configured to electrically connect the first and second electrodes  131 ,  132 , whereby when connecting with the power source, the LED chips  11  emit light, and the voltage stabilizing module  12  discharges the irregular current or static electricity. The second electrode  132  is formed on the first surface  101  of the base  100  and bends and extends to the second surface  102  of the base  100 . The first electrode  131  can also penetrate through the base  100  and extend to the second surface  102  of the base  100 ; thus, the LED package can be formed as a surface mounting device. 
         [0016]    Each of the LED chips  11  has two poles, i.e., anode pole  111  and cathode pole  112 . The poles  111 ,  112  are electrically connected to the first and second electrodes  131 ,  132  respectively via metal wires (not labeled). The LED chips  11  can be only one, or can be more than two in an alternative embodiment. When connecting with the power source, the current of the power source is flown through the LED chips  11  for emitting light, while the irregular current or static electricity can be discharged by the voltage stabilizing module  12 . 
         [0017]    The encapsulative layer  14  is made of transparent or translucent materials. The encapsulative layer  14  is formed on the base  100  and encapsulates the LED chips  11 . Phosphors can be contained in the encapsulative layer  14 . 
         [0018]    Compared with the conventional package structure, the LED package of the present disclosure provides the voltage stabilizing module  12  in an annular shape and in a position between the first and second electrodes  131 ,  132 , the thickness and indeed the volume of the LED package is therefore decreased. Simultaneously, the annular voltage stabilizing module  12  positioned between the first and second electrodes  131 ,  132  ensures a stable connection therebetween; thus, the object of preventing the LED package from breaking down such as via static electricity is achieved. Furthermore, the LED package in accordance with the present disclosure is more durable and reliable. 
         [0019]    Furthermore, the LED package can be formed as a surface mounting device thanks to the base  100  being formed of nonconductive materials, i.e., being insulated, and there is no need to form an insulating material on the base  100 . 
         [0020]    A method of manufacturing the LED package of the present disclosure now will be described in detail hereinafter with reference to  FIG. 3 . 
         [0021]    First, an electrically insulated base  100  is provided. The base  100  may be made of the following one or more than one of the materials: Si, GaAs, ZnO and InP. The base  100  has a first surface  101  and a second surface  102  opposite to the first surface  101 . A protrusion  103  is extended upwardly and annularly from the first surface  101  by patternizing the first surface  101  via etching or microlithography. 
         [0022]    Second, a first doping layer  121  and a second doping layer  122  are formed in the protrusion  103  by doping the protrusion  103  with two different elements or two types of different elements. An annular voltage stabilizing module  12  is thus formed and in the shape of the protrusion  103 . The type of doping can be epitaxial doping or iron implantation. The first doping layer  121  is a P-type doping layer, and the second doping layer  122  is an N-type doping layer. The first doping layer  121  and the second doping layer  122  are arranged side by side. The first and second doping layers  121 ,  122  are positioned in a same level and have an identical thickness. 
         [0023]    Third, a first electrode  131  is formed on a center portion of the first surface  101  of the base  100 . The first electrode  131  is encircled by and attached to the second doping layer  122  of the voltage stabilizing module  12 . The first electrode  131  penetrates through the base  100  and extends to the second surface  102  of the base  100 . A second electrode  132  is formed on a periphery portion of the first surface  101  of the base  100 . The second electrode  132  encircles and is attached to the first doping layer  121  of the voltage stabilizing module  12 . The second electrode  132  bends and extends to the second surface  102  of the base  100 . The first electrode  131  and the second electrode  132  are electrically insulated from each other on the second surface  102  of the base  100 . 
         [0024]    Fourth, two LED chips  11  are mounted on the first electrode  131 . The LED chips  11  are electrically connected to the first and second electrodes  131 ,  132  via wire bonding. The voltage stabilizing module  12  connects to the LED chips  11  in reverse parallel. The voltage stabilizing module  12  has a polarity opposite to that of the LED chips  11 ; that is, when connecting a power source to the LED package, the anode of the power source connects to the anode pole  111  of the LED chip  11  via the first electrode  131 , which connects with a P-type semiconductor layer of the LED chip  11 , while the anode of the power source connects to the second doping layer  122  of the voltage stabilizing module  12  via the first electrode  131 , which is an N-type doping layer (i.e., an N-type semiconductor layer). 
         [0025]    At last, an encapsulative layer  14  is formed on the base  100  and covers the LED chips  11 . The encapsulative layer  14  is made of transparent or translucent materials. Phosphors can be contained in the encapsulative layer  14 . 
         [0026]    It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.