Ultra-thin printed LED layer removed from substrate

• US 9,299,887 B2
• Filed: 03/12/2014
• Issued: 03/29/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: NthDegree Technologies Worldwide Inc.
• Original Assignee: NthDegree Technologies Worldwide Inc.
• Inventors: Lowenthal, Mark David, Baldridge, Jeffrey
• Primary Examiner(s): Payen, Marvin
• Assistant Examiner(s): JOY, JEREMY J
• Application Number:
  US14/206,985
• Publication Number:
  US 20140264396A1
• Time in Patent Office: 748 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 2221/68381 Details of chemical or physical process used for separating the auxiliary support from a device or wafer
• CPC Class Codes: H01L 2224/95085 being a liquid, e.g. for fluidic self-assembly
• CPC Class Codes: H01L 2224/95101 in a liquid medium
• CPC Class Codes: H01L 24/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/1033 Gallium nitride [GaN]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Ultra-thin flexible LED lamp layers are formed over a release layer on a substrate. The LED lamp layers include a first conductor layer overlying the release layer, an array of vertical light emitting diodes (VLEDs) printed over the first conductor layer, where the VLEDs have a bottom electrode electrically contacting the first conductor layer, and a second conductor layer overlying the VLEDs and contacting a top electrode of the VLEDs. Other layers may be formed, such as protective layers, reflective layers, and phosphor layers. The LED lamp layers are then peeled off the substrate, wherein the release layer provides a weak adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage. The resulting LED lamp layers are extremely flexible, enabling the LED lamp layers to be adhered to flexible target surfaces including clothing.

Claims

1. A method of forming an illumination structure comprising:

providing a substrate;

providing a release layer overlying the substrate;

forming a first conductor layer overlying the release layer;

depositing an array of vertical light emitting diodes (VLEDs) over the first conductor layer, the VLEDs having a bottom electrode electrically contacting the first conductor layer;

forming a second conductor layer overlying the VLEDs, the VLEDs having a top electrode electrically contacting the second conductor layer, wherein the first conductor layer, the VLEDs and the second conductor layer comprise flexible LED lamp layers; and

removing the LED lamp layers from the substrate, wherein the release layer provides an adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage,

wherein a surface of the LED lamp layers opposing the substrate is a bottom surface and a surface of the LED lamp layers facing away from the substrate is a top surface, the method further comprising adhering the bottom surface of the LED lamp layers to a target surface after removing the LED lamp layers from the substrate, wherein light exits the top surface of the LED lamp layers.

3. The method of claim 1 wherein at least one of the first conductor layer or the second conductor layer is transparent to allow light from the VLEDs to pass through.

4. The method of claim 1 further comprising adhering the LED lamp layers to a target surface after removing the LED lamp layers from the substrate.

5. The method of claim 1 further comprising adhering the LED lamp layers to a target surface prior to removing the LED lamp layers from the substrate, then removing the LED lamp layers from the substrate.

7. The method of claim 1 wherein the release layer remains adhered to the substrate after removing the LED lamp layers from the substrate.

8. The method of claim 1 wherein the release layer comprises a varnish.

9. The method of claim 1 wherein the release layer is a thermoplastic.

12. The method of claim 1 wherein the substrate and LED lamp layers are flexible.

13. The method of claim 1 wherein the substrate and LED lamp layers are flexible and the steps of forming the first conductor layer, depositing the array of VLEDs over the first conductor layer, and forming the second conductor layer overlying the VLEDs are performed in a roll-to-roll process.

15. The method of claim 1 wherein the step of depositing the array of VLEDs over the first conductor layer comprises printing the array of VLEDs over the first conductor layer.

16. The method of claim 1 wherein the step of removing the LED lamp layers from the substrate comprises peeling the LED lamp layers off the substrate.

17. The method of claim 1 further comprising applying a voltage differential between the first conductor layer and the second conductor layer to illuminate the VLEDs.

18. The method of claim 1 wherein the LED lamp layers are substantially transparent, the method further comprising adhering the LED lamp layers to a target surface such that the target surface is visible through the LED lamp layers.

2. A method of forming an illumination structure comprising:

providing a substrate;

providing a release layer overlying the substrate;

forming a first conductor layer overlying the release layer;

depositing an array of vertical light emitting diodes (VLEDs) over the first conductor layer, the VLEDs having a bottom electrode electrically contacting the first conductor layer;

forming a second conductor layer overlying the VLEDs, the VLEDs having a top electrode electrically contacting the second conductor layer, wherein the first conductor layer, the VLEDs and the second conductor layer comprise flexible LED lamp layers;

removing the LED lamp layers from the substrate, wherein the release layer provides an adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage; and

at least one intermediate layer between the release layer and the first conductor layer.

10. The method of claim 2 wherein a surface of the LED lamp layers opposing the substrate is a bottom surface and a surface of the LED lamp layers facing away from the substrate is a top surface, the method further comprising adhering the bottom surface of the LED lamp layers to a target surface after removing the LED lamp layers from the substrate, wherein light exits the top surface of the LED lamp layers.

6. A method of forming an illumination structure comprising:

providing a substrate;

providing a release layer overlying the substrate;

forming a first conductor layer overlying the release layer;

depositing an array of vertical light emitting diodes (VLEDs) over the first conductor layer, the VLEDs having a bottom electrode electrically contacting the first conductor layer;

forming a second conductor layer overlying the VLEDs, the VLEDs having a top electrode electrically contacting the second conductor layer, wherein the first conductor layer, the VLEDs and the second conductor layer comprise flexible LED lamp layers; and

removing the LED lamp layers from the substrate, wherein the release layer provides an adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage,

wherein the release layer remains adhered to the LED lamp layers after removing the LED lamp layers from the substrate.

11. A method of forming an illumination structure comprising:

providing a substrate;

providing a release layer overlying the substrate;

forming a first conductor layer overlying the release layer;

depositing an array of vertical light emitting diodes (VLEDs) over the first conductor layer, the VLEDs having a bottom electrode electrically contacting the first conductor layer;

forming a second conductor layer overlying the VLEDs, the VLEDs having a top electrode electrically contacting the second conductor layer, wherein the first conductor layer, the VLEDs and the second conductor layer comprise flexible LED lamp layers; and

removing the LED lamp layers from the substrate, wherein the release layer provides an adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage,

wherein a surface of the LED lamp layers opposing the substrate is a bottom surface and a surface of the LED lamp layers facing away from the substrate is a top surface, the method further comprising adhering the top surface of the LED lamp layers to a target surface after removing the LED lamp layers from the substrate, wherein light exits the bottom surface of the LED lamp layers.

14. A method of forming an illumination structure comprising:

providing a substrate;

providing a release layer overlying the substrate;

forming a first conductor layer overlying the release layer;

depositing an array of vertical light emitting diodes (VLEDs) over the first conductor layer, the VLEDs having a bottom electrode electrically contacting the first conductor layer;

forming a second conductor layer overlying the VLEDs, the VLEDs having a top electrode electrically contacting the second conductor layer, wherein the first conductor layer, the VLEDs and the second conductor layer comprise flexible LED lamp layers; and

removing the LED lamp layers from the substrate, wherein the release layer provides an adherence between the substrate and the LED lamp layers to allow the LED lamp layers to be separated from the substrate without damage,

wherein the substrate and LED lamp layers are flexible and the steps of forming the first conductor layer, depositing the array of VLEDs over the first conductor layer, and forming the second conductor layer overlying the VLEDs are performed in a roll-to-roll process, and

wherein the step of removing the LED lamp layers from the substrate is also performed in the roll-to-roll process.