Display contrast

Patent metadata

Field	Value
Publication number	US-10490715-B2
Application number	US-201715587328-A
Country	US
Kind code	B2
Filing date	May 4, 2017
Priority date	Dec 20, 2011
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Display devices with improved display contrast and methods of manufacturing the display devices. Some embodiments include a method of manufacturing a light emitting diode (LED) array. The method includes forming a first mesa area of a first LED and a second mesa area of a second LED, where a trench is defined between the first and second mesa areas. At least a portion of the trench is filled with a non-transparent or substantially non-transparent polymeric material that absorbs light emitted from the first and second LEDs.

First claim

The invention claimed is:

1. A method of manufacturing a light emitting diode (LED) array comprising:
forming a first mesa area of a first LED and a second mesa area of a second LED, wherein a trench is defined between the first and second mesa areas; and
filling at least a portion of the trench with a polymeric material having a thickness such that the polymeric material is non-transparent to light emitted from the first and second LEDs and absorbs the light, at least a portion of the light absorbed by the polymeric material from the first LED being reflected from the first mesa area toward the polymeric material.

2. The method of claim 1 , wherein the polymeric material is one of: polymide, epoxy, or benozcyclobutene.

3. The method of claim 1 , further comprising:
forming a first pixel on the first mesa area and a second pixel on the second mesa area;
filling the polymeric material to extend above the first pixel and the second pixel;
etching a first space within the polymeric material above the first pixel of the first mesa area and a second space within the polymeric material above the second pixel of the second mesa area; and
depositing a first metal within the first space and a second metal within the second space.

4. The method of claim 3 , further comprising depositing a metal layer on top of the polymeric material to electrically connect the first metal and the second metal.

5. The method of claim 4 , wherein;
the first and second mesa areas are of different heights; and
the polymeric material provides a conformal layer for depositing the metal layer.

6. The method of claim 1 , wherein forming the first mesa area and the second mesa area includes performing dry etching on a semiconductor layer.

7. The method of claim 1 , further comprising curing the polymeric material subsequent to filling the at least a portion of the trench with the polymeric material.

8. The method of claim 1 , wherein the first and second mesa areas are formed on a semiconductor layer, and the polymeric material at the trench absorbs the light emitted from the first and second LEDs and propagated through the semiconductor layer.

9. The method of claim 1 , wherein filling the at least a portion of the trench with the polymeric material includes annealing the polymeric material in an oxygen atmosphere.

10. The method of claim 1 , wherein the first and second LEDs are micro-LEDs.

11. The method of claim 1 , wherein filling the at least a portion of the trench with the polymeric material includes forming a polymeric material layer over the first and second mesa areas.

12. A light emitting diode (LED) array, comprising:
a first mesa area of a first LED;
a second mesa area of a second LED, a trench defined between the first and second mesa areas; and
a polymeric material within the trench having a thickness such that the polymeric material is non-transparent to light emitted from the first and second LEDs and absorbs the light, at least a portion of the light absorbed by the polymeric material from the first LED is reflected from the first mesa area toward the polymeric material.

13. The LED array of claim 12 , wherein the polymeric material is one of: polymide, epoxy, or benozcyclobutene.

14. The LED array of claim 12 , wherein:
a first pixel is formed on the first mesa area and a second pixel is formed on the second mesa area;
the polymeric material within the trench extends above the first pixel and the second pixel;
the polymeric material defines a first space within the polymeric material above the first pixel of the first mesa area and a second space within the polymeric material above the second pixel of the second area; and
the LED array further includes a first metal deposited within the first space and a second metal deposited within the second space.

15. The LED array of claim 14 , further comprising a metal layer on top of the polymeric material to electrically connect the first metal and the second metal.

16. The LED array of claim 15 , wherein:
the first and second mesa areas are of different heights; and
the polymeric material provides a conformal layer for the metal layer disposed on top of the polymeric material.

17. The LED array of claim 12 , wherein the first and second mesa areas are formed on a semiconductor layer, and the polymeric material at the trench absorbs the light emitted from the first and second LEDs and propagated through the semiconductor layer.

18. The LED array of claim 12 , wherein the first and second LEDs are micro-LEDs.

Assignees

• Facebook Tech Llc

Inventors

• Gong Zheng
• Small James
• Bonar James Ronald

Classifications

• G02B5/003

  Light absorbing elements · CPC title

• H01L33/58 Primary

  Electricity · mapped topic

• H01L2933/0066

  Electricity · mapped topic

• H01L2933/0058

  Electricity · mapped topic

• H01L33/005

  Electricity · mapped topic