Micro-transfer printed LED and color filter structure

• US 10,008,483 B2
• Filed: 03/17/2017
• Issued: 06/26/2018
• Est. Priority Date: 04/05/2016
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Cok, Ronald S., Bower, Christopher Andrew
• Primary Examiner(s): Gebreyesus, Yosef
• Application Number:
  US15/461,871
• Publication Number:
  US 20170287882A1
• Time in Patent Office: 466 Days
• CPC Class Codes: H01L 24/00 Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/50 Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

A micro-transfer printed intermediate structure comprises an intermediate substrate and one or more pixel structures disposed on the intermediate substrate. Each pixel structure includes an LED, a color filter, and a fractured pixel tether physically attached to the pixel structure. A fractured intermediate tether is physically attached to the intermediate substrate. A method of making an intermediate structure source wafer comprises providing a source wafer having a patterned sacrificial layer including sacrificial portions separated by anchors, disposing an intermediate substrate over the patterned sacrificial layer, and disposing one or more pixel structures on the intermediate substrate entirely on or over each sacrificial portion. Each pixel structure includes an LED, a color filter, and a fractured pixel tether physically attached to the pixel structure to form an intermediate structure.

Claims

1. A color-filter source wafer, comprising:

a source wafer comprising a patterned sacrificial layer comprising sacrificial portions separated by anchors;

a plurality of color filters, wherein for each sacrificial portion in the sacrificial layer, a color filter of the plurality of color filters is disposed entirely on or over the sacrificial portion; and

one or more color-filter tethers physically connecting (i) each color filter of the plurality of color filters or (ii) one or more layers formed in contact with each color filter of the plurality of color filters, to a corresponding anchor in the patterned sacrificial layer.

2. The color-filter source wafer of claim 1, wherein:

(i) each color filter of the plurality of color filters comprises one or more of a curable resin, a dye, a pigment, a color conversion material, a semiconductor crystal, a phosphor and a quantum dot;

(ii) the source wafer comprises at least one of a glass, a polymer, a semiconductor and silicon;

(iii) the sacrificial portions comprise at least one of a designated portion of an anisotropically etchable silicon and a designated portion of a selectively etchable material;

or

(iv) any combination of (i), (ii), and (iii).

3. The color-filter source wafer of claim 1, wherein each color filter of the plurality of color filters and the corresponding one or more color-filter tethers comprise at least one common material.

4. The color-filter source wafer of claim 1, comprising a corresponding encapsulation layer at least partially encapsulating each color filter of the plurality of color filters, wherein the one or more color-filter tethers and the corresponding encapsulation layer for each color filter of the plurality of color filters comprises at least one common material.

5. The color-filter source wafer of claim 4, wherein at least a portion of the corresponding encapsulation layer forms the one or more color-filter tethers for each of the plurality of color filters.

6. A method of making a color-filter source wafer, comprising:

providing a source wafer comprising a patterned sacrificial layer comprising sacrificial portions separated by anchors;

disposing a color filter layer on or over the wafer; and

patterning a color filter entirely on or over each of the sacrificial portions.

7. The method of claim 6, comprising disposing an encapsulation layer encapsulating the color filter for each of the sacrificial portions.

8. The method of claim 6, comprising etching each of the sacrificial portions to form one or more color-filter tethers physically connecting each of the color filters entirely on or over the sacrificial portions, or layers formed in contact with each of the color filters entirely on or over the sacrificial portions, to one of the anchors.

9. The method of claim 8, comprising micro-transfer printing at least one of the color filters disposed on or over the sacrificial portions from the color-filter source wafer to a destination substrate.

10. A pixel structure source wafer, comprising:

a source wafer comprising a patterned sacrificial layer comprising sacrificial portions separated by anchors;

a plurality of LEDs, wherein, for each sacrificial portion in the patterned sacrificial layer, an LED of the plurality of LEDs is disposed entirely on or over the sacrificial portion and the LED has a light-emitting side;

a color filter disposed adjacent to the light-emitting side of each LED of the plurality of LEDs; and

one or more pixel tethers physically connecting each LED of the plurality of LEDs or the color filter disposed adjacent to the light-emitting side of each LED of the plurality LEDs to a corresponding anchor in the patterned sacrificial layer.

11. The pixel structure source wafer of claim 10, wherein:

(i) the color filter comprises one or more of a curable resin, a dye, a pigment, a color conversion material, a semiconductor crystal, a phosphor and a quantum dot;

(ii) the source wafer comprises at least one of a glass, a polymer, a semiconductor and silicon;

(iii) the sacrificial portions comprise at least one of a designated portion of an anisotropically etchable silicon and a designated portion of a selectively etchable material;

or

(iv) any combination of (i), (ii), and (iii).

12. The pixel structure source wafer of claim 10, wherein the one or more pixel tethers and corresponding LED of the plurality of LEDs or the color filter disposed adjacent to the light-emitting side of the corresponding LED comprise at least one common material.

13. The pixel structure source wafer of claim 10, comprising a corresponding encapsulation layer at least partially encapsulating each LED of the plurality of LEDs and adjacent color filter, wherein the one or more pixel tethers and the corresponding encapsulation layer for each LED of the plurality of LEDs comprises at least one common material.

14. The pixel structure source wafer of claim 13, wherein, for each of the plurality of LEDs, at least a portion of the corresponding encapsulation layer forms the one or more fractured pixel tethers or the one or more pixel tethers are attached to the encapsulation layer.

15. An intermediate structure source wafer, comprising:

a source wafer comprising a patterned sacrificial layer comprising sacrificial portions separated by anchors;

a plurality of separate and independent intermediate substrates, each intermediate substrate of the plurality of intermediate substrates disposed entirely over a sacrificial portion in the patterned sacrificial layer;

one or more pixel structures disposed entirely on each intermediate substrate of the plurality of intermediate substrates, wherein each pixel structure of the one or more pixel structures comprises an LED having a light-emitting side, a color filter disposed adjacent to the light-emitting side of the LED, and one or more fractured pixel tethers physically attached to the pixel structure; and

an intermediate tether physically attached to the intermediate substrate or a layer disposed on the intermediate substrate, for each of the intermediate substrates, wherein each intermediate tether physically connects the intermediate substrate or the layer on the intermediate substrate to a corresponding anchor in the patterned sacrificial layer.

16. The intermediate structure source wafer of claim 15, wherein:

(i) the color filter of each of the one or more pixel structures comprises one or more of a curable resin, a dye, a pigment, a color conversion material, a semiconductor crystal, a phosphor and a quantum dot;

(ii) the source wafer comprises at least one of a glass, a polymer, a semiconductor and silicon;

(iii) the intermediate substrate is or includes a glass, a polymer, a semiconductor, or silicon;

(iv) the sacrificial portions comprise at least one of a designated portion of an anisotropically etchable silicon and a designated portion of a selectively etchable material;

or

(v) any combination of (i), (ii), (iii) and (iv).

17. The intermediate structure source wafer of claim 15, wherein, for each of the one or more pixel structures, the one or more fractured pixel tethers and at least one of (i) the color filter and (ii) the LED comprise at least one common material.

18. The intermediate structure source wafer of claim 15, wherein the intermediate tether physically attached to each intermediate substrate of the plurality of intermediate substrates or a layer disposed on each intermediate substrate of the plurality of intermediate substrates and (i) a color filter of the one or more pixel structures disposed entirely on the intermediate substrate or (ii) the intermediate substrate comprise at least one common material.

19. The intermediate structure source wafer of claim 15, wherein each intermediate substrate of the plurality of intermediate substrates comprises at least a portion of the color filter.

20. The intermediate structure source wafer of claim 15, comprising a corresponding encapsulation layer at least partially encapsulating the LED and the color filter for each of the one or more pixel structures, wherein the one or more fractured pixel tethers and the corresponding encapsulation layer, for each of the one or more pixel structures, comprise at least one common material.

21. The intermediate structure source wafer of claim 20, wherein, for each of the one or more pixel structures, at least a portion of the corresponding encapsulation layer forms the one or more fractured pixel tethers or the one or more pixel tethers are attached to the encapsulation layer.

22. The intermediate structure source wafer of claim 15, comprising a corresponding encapsulation layer at least partially encapsulating the LED and the color filter for each of the one or more pixel structures disposed on each of the plurality of intermediate substrates, wherein, for each of the plurality of intermediate substrates, the corresponding encapsulation layer for each of the one or more pixel structures and the intermediate tether comprises at least one common material.

23. The intermediate structure source wafer of claim 22, wherein, for each of the plurality of intermediate substrates, at least a portion of the corresponding encapsulation layer forms the intermediate tether or the intermediate tether is a part of or is attached to the encapsulation layer.