Passivation covered light emitting unit stack

Abstract

A light emitting diode (LED) pixel for a display including a light emitting structure including at least one active layer and configured to generate light, a first passivation layer covering the light emitting structure, a protection structure disposed on the first passivation layer, a plurality of lower via contacts passing through the first passivation layer and electrically connected to the light emitting structure; and a plurality of upper via contacts passing through the protection structure and electrically connected to the lower via contacts, respectively, in which the lower via contacts and the upper via contacts are disposed outside of the at least one active layer.

What is claimed is: 
     
         1 . A light emitting diode (LED) pixel for a display, comprising:
 a light emitting structure comprising at least one active layer and configured to generate light;   a first passivation layer covering the light emitting structure;   a protection structure disposed on the first passivation layer,   a plurality of lower via contacts passing through the first passivation layer and electrically connected to the light emitting structure; and   a plurality of upper via contacts passing through the protection structure and electrically connected to the lower via contacts, respectively,   wherein the lower via contacts and the upper via contacts are disposed outside of the at least one active layer.   
     
     
         2 . The LED pixel for a display of  claim 1 , wherein the light emitting structure comprises:
 a first LED sub-unit;   a second LED sub-unit disposed on the first LED sub-unit; and   a third LED sub-unit disposed on the second LED sub-unit;   wherein the first, second, and third LED sub-units comprise first, second, and third LED stacks, respectively, and   wherein each of the first, second, and third LED stacks comprises a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer.   
     
     
         3 . The LED pixel for a display of  claim 2 , wherein the first LED stack, the second LED stack, and the third LED stack are configured to emit light having different wavelengths from each other. 
     
     
         4 . The LED pixel for a display of  claim 3 , wherein the first LED stack, the second LED stack, and the third LED stack are configured to emit red light, green light, and blue light, respectively, and
 wherein the lower via contacts and the upper via contacts do not overlap the at least one active layer when viewed in plan.   
     
     
         5 . The LED pixel for a display of  claim 2 , further comprising:
 a first thin film conductor electrically coupled with the first LED sub-unit;   a second thin film conductor electrically coupled with the second LED sub-unit;   a third thin film conductor electrically coupled with the third LED sub-unit;   a fourth thin film conductor electrically coupled with the first, second, and third LED sub-units in common,   wherein the first, second, third, and fourth thin film conductors are disposed on the light emitting structure.   
     
     
         6 . The LED pixel for a display of  claim 5 , wherein the lower via contacts comprise first, second, third, and fourth via contacts, and the upper via contacts comprise first, second, third, and fourth upper via contacts electrically connected to the first, second, third, and fourth lower via contacts, respectively. 
     
     
         7 . The LED pixel for a display of  claim 6 , wherein at least one of the first, second, third, and fourth thin film conductors extends from the top of the light emitting structure towards the outside of the active layers, and
 wherein at least one of the first, second, third, and fourth lower via contacts are electrically connected to at least one of the first, second, third, and fourth thin film conductors.   
     
     
         8 . The LED pixel for a display of  claim 7 , wherein the protection structure comprises a second passivation layer. 
     
     
         9 . The LED pixel for a display of  claim 8 , wherein the first and second passivation layers comprise at least one of polyimide and epoxy molding compound (EMC). 
     
     
         10 . The LED pixel for a display of  claim 8 , wherein a side surface of the first passivation layer and a side surface of the second passivation layer are substantially flush with each other. 
     
     
         11 . The LED pixel for a display of  claim 10 , wherein the upper via contacts have inclined sidewalls. 
     
     
         12 . The LED pixel for a display of  claim 11 , wherein the lower via contacts have inclined sidewalls. 
     
     
         13 . The LED pixel for a display of  claim 12 , wherein the sidewalls of the upper via contacts and the sidewalls of the lower via contacts have the same inclined angle with respect to a bottom surface of the light emitting structure. 
     
     
         14 . The LED pixel for a display of  claim 8 , further comprising:
 a plurality of lower conductive patterns disposed on the first passivation layer and corresponding to the respective lower via contacts; and   a plurality of upper conductive patterns disposed on the second passivation layer and corresponding to the respective upper via contacts.   
     
     
         15 . The LED pixel for a display of  claim 8 , further comprising a substrate on which the light emitting structure is disposed. 
     
     
         16 . The LED pixel for a display of  claim 8 , further comprising a plurality of bumps disposed on the second passivation layer. 
     
     
         17 . The LED pixel for a display of  claim 7 , wherein the protection structure is rigid and comprises a through-silicon via (TSV) substrate. 
     
     
         18 . The LED pixel for a display of  claim 17 , further comprising:
 a plurality of lower conductors disposed on a bottom surface of the TSV substrate; and   a plurality of upper conductors disposed on a top surface of the TSV substrate,   wherein the lower conductors are electrically coupled to the lower via contacts, and   wherein the upper conductors are disposed on the corresponding upper via contacts, respectively.   
     
     
         19 . The LED pixel for a display of  claim 18 , wherein each of the lower via contacts comprises a first portion filling a via hole and a second portion having an area wider than the first portion,
 wherein the lower conductors disposed on the TSV substrate are coupled to the second portions of the via contacts, respectively, and   wherein the second portions and the corresponding lower conductors have the same area as each other.   
     
     
         20 . The LED pixel for a display of  claim 12 , wherein the sidewalls of the upper via contacts and the sidewalls of the lower via contacts have different inclined angles with respect to a bottom surface of the light emitting structure.