Thermal transfer element and process for forming organic electroluminescent devices

• US 6,194,119 B1
• Filed: 12/28/1999
• Issued: 02/27/2001
• Est. Priority Date: 01/15/1999
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: McCormick, Fred B., Hsu, Yong, Wolk, Martin B., Baude, Paul F.
• Primary Examiner(s): Schilling, Richard L.
• Application Number:
  US09/473,115
• Time in Patent Office: 427 Days
• Field of Search: 430/200, 430/273.1, 430/271.1, 430/312, 430/319, 430/964, 503/227, 156/234, 427/66, 346/135.1
• US Class Current: 430/200
• CPC Class Codes: B41M 3/006 Patterns of chemical products used for a specific purpose, e.g. pesticides, perfumes, adhesive patterns; use of microencapsulated material; Printing on smoking articles
• CPC Class Codes: B41M 5/265 for the production of optical filters or electrical components
• CPC Class Codes: B41M 5/38207 characterised by aspects not provided for in groups B41M5/385 - B41M5/395
• CPC Class Codes: B41M 5/38214 Structural details, e.g. multilayer systems composition of individual layers B41M5/42
• CPC Class Codes: B41M 5/392 Additives, other than colour forming substances, dyes or pigments, e.g. sensitisers, transfer promoting agents
• CPC Class Codes: B41M 5/395 Macromolecular additives, e.g. binders
• CPC Class Codes: B41M 5/42 Intermediate, backcoat, or covering layers B41M5/405 takes precedence; multilayer thermal transfer systems in general B41M5/38214
• CPC Class Codes: G02B 6/1221 made from organic materials
• CPC Class Codes: G02B 6/138 by using polymerisation
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H05K 3/046 by selective transfer or selective detachment of a conductive layer
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/10 Deposition of organic active material
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing
• CPC Class Codes: H10K 71/18 using non-liquid printing techniques, e.g. thermal transfer printing from a donor sheet
• CPC Class Codes: H10K 71/421 using coherent electromagnetic radiation, e.g. laser annealing
• CPC Class Codes: Y10S 430/165 Thermal imaging composition
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]

Abstract

Disclosed are thermal transfer elements and processes for patterning solvent-coated layers and solvent-susceptible layers onto the same receptor substrate. These donor elements and methods are particularly suited for making organic electroluminescent devices and displays. The donor elements can include a substrate, an optional light-to-heat conversion layer, and a single or multicomponent transfer layer that can be imagewise transferred to a receptor to form an organic electroluminescent device, portions thereof, or components therefor. The methods offer advantages over conventional patterning techniques such as photolithography, and make it possible to fabricate new organic electroluminescent device constructions.

Claims

1. A thermal transfer donor element for use in making organic electroluminescent devices, comprising in the following order:

a substrate;

a light-to-heat conversion layer;

an interlayer; and

a thermal transfer layer including, in the following order, a release layer, a cathode layer, a light emitting polymer layer, a small molecule hole transport layer, and an anode layer.

2. A method for patterning a first material and a second material on a receptor, which method comprises selectively thermal transferring the first material proximate to the second material on the receptor from a first donor element, the first material being formed on the donor element by solution coating using a solvent, the second material being incompatible with said solvent, wherein at least one of the first and second materials comprises an organic electroluminescent material, an organic conductor, or an organic semiconductor.

3. The method of claim 2, wherein the first material comprises a light emitting polymer.

4. The method of claim 2, wherein the second material comprises an organic small molecule material.

5. The method of claim 2, further comprising selectively thermal transferring the second material on the receptor from a second donor element.

6. The method of claim 2, wherein the second material is selectively thermal transferred along with the first material from the first donor sheet to the receptor.

7. The method of claim 2, wherein the first material is transferred next to the second material on the receptor.

8. The method of claim 2, wherein after transfer the second material is disposed between the first material and the receptor.

9. The method of claim 2, wherein the step of selectively thermal transferring the first material from the first donor element comprises selectively heating the first donor element using a thermal print head.

10. The method of claim 2, wherein the first donor element comprises a substrate and a light-to-heat conversion layer disposed between the substrate and the first material, and wherein the step of selectively thermal transferring the first material comprises selectively exposing the first donor element to imaging radiation.

11. A method for patterning materials comprising the steps of:

forming a donor element comprising a donor substrate and a multicomponent thermal transfer layer, the thermal transfer layer having at least a first layer comprising a solvent-coated material and a second layer comprising a solvent-susceptible material, the solvent-susceptible material being incompatible with the solvent used to coat the solvent-coated material, wherein the first layer is disposed between the second layer and the donor substrate;

placing the thermal transfer layer proximate a receptor; and

selectively thermally transferring the multicomponent transfer layer from the donor element to the receptor,

wherein at least one of the solvent-coated material and the solvent-susceptible material comprises an organic electroluminescent material, an organic conductor, or an organic semiconductor.

12. The method of claim 11, wherein the first layer comprises a light emitting polymer.

13. The method of claim 11, wherein the second layer comprises an organic small molecule material.

14. The method of claim 11, wherein the thermal transfer layer comprises a conductor layer, a light emitting polymer layer, and a small molecule layer.

15. The method of claim 11, wherein the donor element comprises a substrate, a light-to-heat conversion layer disposed between the substrate and the thermal transfer layer, and an interlayer disposed between the light-to-heat conversion layer and the thermal transfer layer.

16. The method of claim 15, wherein the donor element further comprises a release layer disposed between the interlayer and the thermal transfer layer.

17. The method of claim 16, wherein the release layer comprises copper phthalocyanine.

18. The method of claim 11, wherein the step of selectively thermally transferring comprises selectively heating the donor element using a thermal print head.

19. The method of claim 11, wherein the step of selectively thermally transferring comprises selectively exposing the donor element to imaging radiation, the donor element including a radiation absorber for converting the imaging radiation into heat.

20. A method for patterning materials comprising the steps of:

thermally transferring selected portions of a first transfer layer from a first donor element to a receptor, the first transfer layer containing a first material, the first material being solution-coated from a solvent onto the first donor; and

thermally transferring selected portions of a second transfer layer from a second donor element to the receptor, the second transfer layer containing a second material, the second material being incompatible with the solvent,

wherein at least one of the first and second materials comprises an organic electroluminescent material, an organic conductor, or an organic semiconductor.

21. The method of claim 20, wherein the first transfer layer comprises multiple layers.

22. The method of claim 20, wherein the second transfer layer comprises multiple layers.

23. The method of claim 20, wherein the first material comprises a light emitting polymer.

24. The method of claim 20, wherein the second material comprises a light emitting organic small molecule.

25. A method for making a thermal transfer donor element, which method comprises forming a donor element that has a donor substrate and a transfer layer, the transfer layer being formed by (a) solution coating a first material using a solvent, (b) drying the first material to substantially remove the solvent, and (c) depositing a second material such that the first material is disposed between the donor substrate and the second material, the second material being incompatible with the solvent used to coat the first material.

26. The method of claim 25, wherein the first material comprises a light emitting polymer.

27. The method of claim 25, wherein the second material comprises an organic small molecule material.