HIGH POWER AllnGaN BASED MULTI-CHIP LIGHT EMITTING DIODE

Abstract

A light emitting diode chip having a substantially transparent substrate and having an aspect ratio which defines an elongated geometry provides enhanced efficiency and brightness. Method for forming and operating the same are also disclosed.

1 . A light emitting diode chip comprising a substantially transparent substrate and having an aspect ratio which defines an elongated geometry. 
     
     
         2 . A light emitting diode chip comprising:
 a substantially transparent substrate;   an active region formed upon the substrate; and   wherein an aspect ratio of the active area is greater than approximately 1.5 to 1.   
     
     
         3 . The device as recited in  claim 2 , wherein the aspect ratio of the active area is greater than approximately 2 to 1. 
     
     
         4 . The device as recited in  claim 2 , wherein the aspect ratio of the active area is between approximately 1.5 to 1 and approximately 10 to 1. 
     
     
         5 . The device as recited in  claim 2 , wherein the aspect ratio of the active area is approximately 4 to 1. 
     
     
         6 . The device as recited in  claim 2 , wherein the width thereof is approximately 250 microns and the length thereof is approximately 1000 microns. 
     
     
         7 . The device as recited in  claim 2 , wherein the active region is configured to operate at between approximately 3.0 volts and approximately 3.5 volts and between approximately 60 milliamps and approximately 90 milliamps. 
     
     
         8 . The device as recited in  claim 2 , wherein one light emitting diode device is formed upon the substrate. 
     
     
         9 . The device as recited in  claim 2 , wherein the active area substantially covers a surface of the substrate. 
     
     
         10 . The device as recited in  claim 2 , wherein the substrate comprises a material selected from the group comprising:
 sapphire;   spinel;   ZnO;   SiC;   MgO;   GaN;   AlN; and   AlGaN.   
     
     
         11 . The device as recited in  claim 2 , wherein the active region comprises AlInGaN. 
     
     
         12 . The device as recited in  claim 2 , further comprising:
 an upper LED layer and a lower LED layer cooperating to define the active region; an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer; and   a reflector disposed intermediate the active region and the lower contact finger, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip.   
     
     
         13 . The device as recited in  claim 2 , further comprising:
 an upper LED layer and a lower LED layer cooperating to define the active region;   an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer; and   a reflector formed upon the active region intermediate the active region and the lower contact finger, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip.   
     
     
         14 . The device as recited in  claim 2 , further comprising:
 an upper LED layer and a lower LED layer cooperating to define the active region;   an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer;   a transparent insulator formed upon the active region intermediate the active region and the lower contact finger; and   a reflector formed upon the transparent insulator, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip.   
     
     
         15 . The device as recited in  claim 2 , further comprising:
 an upper LED layer and a lower LED layer cooperating to define the active region;   an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer; and   a reflector formed upon the active region intermediate the active region and the lower contact finger, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip and the reflector being formed of a dielectric.   
     
     
         16 . The device as recited in  claim 2 , further comprising:
 an upper LED layer and a lower LED layer cooperating to define the active region;   an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer;   a transparent insulator formed upon the active region intermediate the active region and the lower contact finger; and   a reflector formed upon the transparent insulator, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip and the reflector being formed of a metal.   
     
     
         17 . A light emitting diode chip comprising:
 a substantially transparent substrate;   an active region formed upon the substrate;   an upper LED layer and a lower LED layer cooperating to define the active region;   an upper contact finger formed upon the upper LED layer;   a lower contact finger formed upon the lower LED layer; and   a reflector disposed intermediate the active region and the lower contact finger, the reflector being configured to reflect light directed from the active region toward the lower contact finger away from the lower contact finger so as to enhance a brightness of the light emitting diode chip.