Micro-Structure Phosphor Coating

Abstract

An optical emitter includes micro-structure phosphor coating on a light-emitting diode die mounted on a package substrate. The micro-structures are transferred onto a micro-structure phosphor coating precursor by patterning and curing the precursor or by curing the precursor through a mold. The micro-structures are half spheroids, three-sided pyramids, or six-sided pyramids.

What is claimed is: 
     
         1 . An optical emitter comprising: a package substrate; a light-emitting diode (LED) die mounted on the package substrate, the LED die comprising an LED; a layer of micro-structure phosphor coating on a surface of the LED die opposite from the package substrate; and a lens over the layer of micro-structure phosphor coating and the LED die, the lens attached to the package substrate. 
     
     
         2 . The optical emitter of  claim 1 , further comprising a layer of conformal phosphor coating between the layer of micro-structure phosphor coating and the surface of the LED die opposite from the package substrate. 
     
     
         3 . The optical emitter of  claim 1 , wherein the layer of micro-structure phosphor coating comprises a plurality of micro-structures having a pitch of about 10 to 50 microns. 
     
     
         4 . The optical emitter of  claim 3 , wherein the micro-structures are half spheroids. 
     
     
         5 . The optical emitter of  claim 3 , wherein the micro-structures are pyramids. 
     
     
         6 . The optical emitter of  claim 5 , wherein the pyramids are three-sided or six-sided. 
     
     
         7 . The optical emitter of  claim 1 , wherein the layer of micro-structure phosphor coating has a thickness of about 10-50 microns. 
     
     
         8 . The optical emitter of  claim 3 , wherein the layer of micro-structure phosphor coating has non-uniform micro-structure density. 
     
     
         9 . The optical emitter of  claim 3 , wherein the layer of micro-structure phosphor coating includes micro-structures of different shapes. 
     
     
         10 . The optical emitter of  claim 3 , wherein the layer of micro-structure phosphor coating includes hardened ultraviolet (UV) gel, thermal gel, or photoresist. 
     
     
         11 . An optical emitter, comprising:
 a package substrate;   a light-emitting diode (LED) disposed over the package substrate;   a plurality of phosphor micro-structures disposed over the LED, wherein each of the phosphor micro-structures have a non-planar shape; and   a lens disposed over the package substrate, wherein the LED and the phosphor micro-structures disposed thereover are housed within the lens.   
     
     
         12 . The optical emitter of  claim 11 , wherein the LED is flip-chip bonded to the package substrate through a conductive layer disposed between the LED and the package substrate. 
     
     
         13 . The optical emitter of  claim 11 , wherein the phosphor micro-structures are each shaped as a half spheroid or a multi-sided pyramid. 
     
     
         14 . The optical emitter of  claim 11 , further comprising: a cured uniform coating precursor layer disposed between the LED and the phosphor micro-structures. 
     
     
         15 . The optical emitter of  claim 11 , wherein the plurality of phosphor micro-structures have a pitch in a range from about 10 microns to about 50 microns. 
     
     
         16 . The optical emitter of  claim 11 , wherein the plurality of phosphor micro-structures each have a thickness in a range from about 10 microns to about 50 microns. 
     
     
         17 . An optical emitter, comprising:
 a package substrate;   a conductive layer disposed over the package substrate;   a light-emitting diode (LED) die bonded to the package substrate through the conductive layer;   a phosphor layer disposed over the LED die, wherein the phosphor layer contains a plurality of phosphor elements that are each shaped as a half spheroid or as a multi-sided pyramid; and   a lens disposed over the package substrate, wherein the LED die and the phosphor layer are located underneath the lens.   
     
     
         18 . The optical emitter of  claim 17 , wherein the LED die is flip-chip bonded to the package substrate through the conductive layer. 
     
     
         19 . The optical emitter of  claim 17 , further comprising: a cured uniform coating precursor layer disposed between the LED die and the phosphor layer. 
     
     
         20 . The optical emitter of  claim 17 , wherein:
 the plurality of phosphor elements have a pitch in a range from about 10 microns to about 50 microns; and   the phosphor layer has a thickness in a range from about 10 microns to about 50 microns.