Wafer level packaging of multiple light emitting diodes (leds) on a single carrier die

Abstract

An LED wafer includes LED dies on an LED substrate. The LED wafer and a carrier wafer are joined. The LED wafer that is joined to the carrier wafer is shaped. Wavelength conversion material is applied to the LED wafer that is shaped. Singulation is performed to provide multiple LED dies that are joined to a single carrier die. The multiple LED dies on the single carrier die are connected in series and/or in parallel by interconnection in the LED dies and/or in the single carrier die. The singulated devices may be mounted in an LED fixture to provide high light output per unit area. Related devices and fabrication methods are described.

1 .- 20 . (canceled) 
     
     
         21 . A method for fabricating a lighting device, the method comprising:
 growing epitaxial layers over an inner face of a growth substrate and defining a plurality of trenches in the epitaxial layers to produce an array of LEDs;   providing a plurality of anode contacts and a plurality of cathode contacts in conductive electrical communication with the array of LEDs;   mounting the array of LEDs over a carrier, including establishing conductive electrical communication between the plurality of anode contacts and a plurality of anode pads of the carrier, and establishing conductive electrical communication between the plurality of cathode contacts and a plurality of cathode pads of the carrier; and   processing at least one light extraction surface including an outer face of the growth substrate to shape and/or texture the at least one light extraction surface, wherein the processing of the at least one light extraction surface is performed after the mounting of the array of LEDs over the carrier.   
     
     
         22 . The method of  claim 21 , wherein the processing of the at least one light extraction surface comprises shaping the light extraction surface to bevel portions of the at least one light extraction surface. 
     
     
         23 . The method of  claim 22 , wherein the shaping of the light extraction surface to bevel portions of the at least one light extraction surface comprises forming bevels with a saw blade or laser. 
     
     
         24 . The method of  claim 22 , wherein the shaping of the light extraction surface to bevel portions of the at least one light extraction surface comprises forming bevels by wet and/or dry etching. 
     
     
         25 . The method of  claim 22 , wherein the shaping of the light extraction surface to bevel portions of the at least one light extraction surface comprises beveling areas of the substrate between individual LEDs of the array of LEDs. 
     
     
         26 . The method of  claim 22 , wherein the shaping of the light extraction surface to bevel portions of the at least one light extraction surface forms a plurality of facets on the at least one light extraction surface. 
     
     
         27 . The method of  claim 21 , wherein the processing of the at least one light extraction surface comprises texturing the at least one light extraction surface. 
     
     
         28 . The method of  claim 27 , wherein the texturing of the at least one light extraction surface comprises etching the at least one light extraction surface. 
     
     
         29 . The method of  claim 27 , wherein the texturing of the at least one light extraction surface comprises texturing outer faces and sidewalls of LEDs of the array of LEDs. 
     
     
         30 . The method of  claim 21 , wherein the processing of the at least one light extraction surface further comprises thinning the growth substrate. 
     
     
         31 . The method of  claim 30 , wherein the thinning of the growth substrate is performed prior to the processing to shape and/or texture the at least one light extraction surface. 
     
     
         32 . The method of  claim 21 , further comprising defining a plurality of recesses in the growth substrate in a direction extending from the outer face toward the inner face. 
     
     
         33 . The method of  claim 21 , further comprising applying a wavelength conversion material on or over the at least one light extraction surface. 
     
     
         34 . The method of  claim 33 , wherein the applying of a wavelength conversion material on or over the at least one light extraction surface comprises applying wavelength conversion material by spraying. 
     
     
         35 . The method of  claim 33 , wherein the applying of a wavelength conversion material on or over the at least one light extraction surface comprises applying wavelength conversion material over outer faces and sidewalls of LEDs of the array of LEDs. 
     
     
         36 . The method of  claim 33 , wherein the wavelength material is applied into trenches between LEDs of the array of LEDs. 
     
     
         37 . The method of  claim 21 , wherein the array of LEDs is embodied in an LED wafer. 
     
     
         38 . The method of  claim 21 , further comprising electrically connecting at least some LEDs of the array of LEDs in series and/or in parallel. 
     
     
         39 . The method of  claim 21 , further comprising singulating some LEDs of the array of LEDs to form a plurality of LED chips. 
     
     
         40 . A lighting device produced by the method of  claim 21 .