Display device using semiconductor light-emitting element

Patent metadata

Field	Value
Publication number	US-11437352-B2
Application number	US-201817254656-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	Jun 22, 2018
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

Discussed are a display device, and a method of manufacturing the display device. The display device includes a substrate having a plurality of metal pads, and a semiconductor light-emitting element electrically connected to the plurality of metal pads through self-assembly. Specifically, each metal pad includes a bonding metal electrically connected to a conductive electrode of a respective semiconductor light-emitting element, and a coating layer encompassing the bonding metal.

First claim

What is claimed is:

1. A display device, comprising:
a substrate having a plurality of metal pads; and
a semiconductor light-emitting element electrically connected to the plurality of metal pads through self-assembly,
wherein each metal pad comprises:
a metal layer;
a bonding metal provided on the metal layer, and electrically connected to the semiconductor light-emitting element; and
a coating layer surrounding the bonding metal, and

wherein the coating layer is formed of an amphiphilic organic material.

2. The display device of claim 1 , wherein the bonding metal comprises at least one of copper (Cu), silver (Ag), indium (In), tin (Sn), and bismuth (Bi).

3. The display device of claim 1 , wherein the coating layer is formed of oleic acid.

4. The display device of claim 1 , wherein a hydrophilic portion of the amphiphilic organic material forms an electrostatic bond with a natural oxide layer of the bonding metal to form the coating layer.

5. A method of manufacturing a display device, the method comprising:
coupling a semiconductor light-emitting element to a substrate on which a plurality of metal pads are formed through self-assembly in a fluid-filled chamber,
wherein a metal pad among the plurality of metal pads is formed on the substrate by:
forming a metal layer on the substrate to form ohmic contact with the semiconductor light-emitting element;
forming a bonding metal electrically connected to a conductive electrode of the semiconductor light-emitting element on the substrate; and
forming a coating layer surrounding the bonding metal,

wherein in the forming of the coating layer surrounding the bonding metal,
the coating layer surrounding the bonding metal is formed of an amphiphilic organic material, and
the substrate on which the bonding metal is formed is immersed in a solution of a predetermined concentration containing the amphiphilic organic material to self-align the amphiphilic organic material on a surface of the bonding metal, and

wherein a hydrophilic portion of the amphiphilic organic material forms an electrostatic bond with a natural oxide layer of the bonding metal to form the coating layer.

6. The method of claim 5 , further comprising:
growing the semiconductor light-emitting element on a growth substrate;
separating the semiconductor light-emitting element from the growth substrate, and fixing the semiconductor light-emitting element to a temporary substrate;
separating the semiconductor light-emitting element from the temporary substrate in the fluid-filled chamber; and
forming a sacrificial layer to surround the semiconductor light-emitting element between growing the semiconductor light-emitting element on the growth substrate and separating the semiconductor light-emitting element therefrom,
wherein the sacrificial layer is a layer removed by a wet etching process.

7. The method of claim 6 , wherein in the separating the semiconductor light-emitting element,
the sacrificial layer is wet etched in a fluid, and the semiconductor light-emitting element is separated from the temporary substrate.

8. The method of claim 5 , wherein in the coupling of the semiconductor light-emitting element to the substrate on which the plurality of metal pads are formed,
the metal pad on which the coating layer is formed and the semiconductor light-emitting element are allowed to collide with each other in a fluid so that the metal pad is coupled to the semiconductor light-emitting element as the coating layer is pushed to an outer edge of the bonding metal due to a surface tension of the coating layer.

9. The method of claim 5 , wherein the forming the coating layer surrounding the bonding metal and the coupling the semiconductor light-emitting element to the substrate on which the plurality of the metal pads are formed are performed a plurality of times.

10. The method of claim 5 , further comprising forming an insulation member on the substrate and the semiconductor light-emitting element.

11. The method of claim 10 , wherein the coating layer is interposed between the bonding metal and the insulating member.

12. The display device of claim 1 , wherein the coating layer surrounds an outer edge of the bonding metal.

13. The display device of claim 1 , further comprising an insulating member disposed on the substrate to surround the semiconductor light-emitting element.

14. The display device of claim 13 , wherein the coating layer is interposed between the bonding metal and the insulating member.

15. A display device, comprising:
a substrate having a plurality of metal pads; and
a plurality of semiconductor light-emitting elements electrically connected to the plurality of metal pads, respectively,
wherein each metal pad comprises:
a bonding metal electrically connected to a respective semiconductor light-emitting element; and
a coating layer on the bonding metal,

wherein the coating layer and the bonding metal are coplanar and disposed on the respective semiconductor light-emitting element, and
wherein the coating layer is formed of an amphiphilic organic material.

16. The display device of claim 15 , wherein the coating layer is disposed at an outer edge of the bonding metal.

17. The display device of claim 15 , further comprising an insulating member disposed on the substrate to surround the respective semiconductor light-emitting element.

18. The display device of claim 17 , wherein the coating layer is interposed between the bonding metal and the insulating member.

Assignees

• Lg Electronics Inc

Inventors

• Kim Junghoon
• Kim Dohee

Classifications

• H10P72/7434

  used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate · CPC title

• H10P72/7428

  used to support diced chips prior to mounting · CPC title

• H10P72/74

  using temporarily an auxiliary support · CPC title

• H10W90/00 Primary

  Package configurations · CPC title

• H10P72/744

  Details of chemical or physical process used for separating the auxiliary support from a device or a wafer · CPC title