High power leds

Abstract

LED chips and packages are disclosed having lenses made of materials that resist degradation at higher operation temperatures and humidity, and methods of fabricating the same. The lenses can be made of certain materials that can withstand high temperatures and high humidity, with the lenses mounted to the LED prior to certain critical metallization steps. This helps avoid damage to the metalized part that might occur as a result of the high mounting or bonding temperature for the lens. One embodiment of an LED chip comprises a flip-chip LED and a lens mounted to the topmost surface of the flip-chip LED. Lenses can be bonded to LEDs at the wafer level or at the chip level. Some of the LED chips and packages can have lenses of different materials with planar and/or curved surfaces.

We claim: 
     
         1 . A light emitting diode chip (LED) chip, comprising:
 an LED on a substrate; and   a lens directly on and covering the top surface of said LED and/or said substrate, with the lens having at least one vertical planar surface.   
     
     
         2 . The LED of  claim 1 , wherein at least one of said at least one vertical planar surface is aligned with an edge of said substrate. 
     
     
         3 . The LED chip of  claim 1 , wherein said lens has a curved surface. 
     
     
         4 . The LED chip of  claim 2 , wherein at least one of said at least one vertical planar surface is aligned with an edge of said LED. 
     
     
         5 . The LED chip of  claim 2 , wherein each said at least one vertical planar surface is aligned with are respective on of the edges of said substrate. 
     
     
         6 . The LED chip of  claim 1 , being square shaped. 
     
     
         7 . The LED chip of  claim 1 , wherein said lens is at least partially hemispheric. 
     
     
         8 . The LED chip of  claim 1 , wherein said lens is molded on said LED. 
     
     
         9 . The LED chip of  claim 3 , wherein each of said at least one vertical planar surface transitions directly into said curved surface. 
     
     
         10 . A light emitting diode chip (LED) chip, comprising:
 an LED on a substrate; and   an encapsulant directly on at least a portion of one surface of said substrate, said encapsulant comprising at least one planar surface, at least one of which is aligned with an edge of said substrate.   
     
     
         11 . The LED chip of  claim 10 , wherein each of said at least one planar surface is aligned with an edge of said substrate. 
     
     
         12 . The LED chip of  claim 10 , wherein said encapsulant further comprises at least one curved surface. 
     
     
         13 . The LED chip of  claim 10 , wherein the edges of said LED are aligned with the edges of said substrate. 
     
     
         14 . The LED chip of  claim 10 , having a square footprint. 
     
     
         15 . The LED chip of  claim 10 , being square shaped. 
     
     
         16 . The LED chip of  claim 10 , wherein said encapsulant is at least partially hemispheric. 
     
     
         17 . The LED chip of  claim 10 , wherein said encapsulant is molded on said substrate. 
     
     
         18 . The LED chip of  claim 10 , wherein all edges of said encapsulant are vertically aligned with the edges of said substrate. 
     
     
         19 . The LED chip of  claim 10 , wherein at least one of said at least one planar surface comprises a vertical planar surface. 
     
     
         20 . The LED chip of  claim 20 , wherein said encapsulant further comprises a curved surface, and wherein each said one vertical planar surface transitions directly into said curved surface. 
     
     
         21 . A light emitting diode (LED) chip, comprising:
 an LED; and   an encapsulant on said LED wherein the top portion of said encapsulant comprises glass.   
     
     
         22 . A light emitting diode (LED) chip wafer, comprising:
 a plurality of LEDs on a substrate;   a plurality of interconnected lenses on said LEDs.   
     
     
         23 . The LED chip wafer of  claim 22 , wherein each lens is over a respective one of said LEDs 
     
     
         24 . The LED chip wafer of  claim 22 , wherein as least some of said lenses are at least partially hemispheric. 
     
     
         25 . Method of forming LED chips, comprising:
 forming a plurality of LEDs on substrate;   forming a plurality of interconnected lenses over said LEDs; and   singulating said LED chips from said substrate.   
     
     
         26 . The method of  claim 25 , wherein each of said interconnected lenses is over a respective one of said LEDs. 
     
     
         27 . The method of  claim 25 , wherein at least some of said lenses are at least partially hemispheric. 
     
     
         28 . The method of  claim 25 , wherein each of said singulated LED chips comprises a lens on and covering substantially of a surface of said LED. 
     
     
         29 . The method of  claim 25 , wherein each of said singulated LED chips comprises a substrate and lens, with said lens having a vertical planar surface. 
     
     
         30 . The method of  claim 29 , wherein each said vertical planar surface is aligned with an edge its said substrate. 
     
     
         31 . The method of  claim 29 , wherein each said lens has a curved surface. 
     
     
         32 . The method of  claim 25 , wherein the top portion of each said lens comprises glass.