Passivation of electroluminescent organic devices

• US 5,811,177 A
• Filed: 11/30/1995
• Issued: 09/22/1998
• Est. Priority Date: 11/30/1995
• Status: Expired due to Term

• Current Assignee: Universal Display Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: So, Franky, Harvey, Thomas B. III, Shi, Song Q.
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US08/565,123
• Time in Patent Office: 1,027 Days
• Field of Search: 313/500, 313/505, 313/506, 313/512, 257/88, 257/98, 257/99, 257/100, 428/690, 428/917, 428/201, 428/209, 428/212, 428/457, 427/66, 427/68, 427/123, 427/126.1, 427/258, 427/404, 427/407.1, 427/419.1, 427/419.8
• US Class Current: 428/209
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A method of passivating electroluminescent organic devices positioned on a supporting substrate including the steps of overcoating or capping the individual pixels, which form an array of electroluminescent organic devices, with a layer of stable metal, overcoating the layer of stable metal with a buffer system including a buffer layer of organic material and a thermal coefficient matching layer on the buffer layer, depositing a low permeability inorganic layer over the thermal coefficient matching layer, and sealing the electroluminescent organic device with an epoxy encapsulant or polymer laminated aluminum foil.

Claims

1. A method of passivating organic devices comprising the steps of:

providing an organic device on a supporting substrate defining a plurality of pixels, each of the plurality of pixels including a cathode comprised of a low work function metal;

individually capping each of the plurality of pixels with a layer of indium;

overcoating the plurality of pixels of the organic device, each individually capped by the layer of indium, with a buffer system for protection of the plurality of pixels from further process steps and materials, including a layer of organic material positioned on each layer of indium;

depositing an inorganic layer over the buffer system; and

sealing the organic device with a sealing layer of one of an epoxy encapsulant or a polymer laminated aluminum foil.

2. A method of passivating organic devices as claimed in claim 1 including a step of depositing a thermal coefficient matching layer on the layer of organic material as a portion of the buffer system.

3. A method of passivating organic devices as claimed in claim 2 wherein the step of depositing the thermal coefficient matching layer on the layer of organic material includes depositing a layer of low work function metal.

4. A method of passivating organic devices as claimed in claim 2 wherein the step of depositing the thermal coefficient matching layer on the layer of organic material includes depositing a layer of gettering material.

5. A method of passivating organic devices as claimed in claim 4 wherein the step of depositing the gettering material includes depositing a layer of low work function metal.

6. A method of passivating organic devices as claimed in claim 5 wherein the step of depositing the layer of low work function metal includes depositing one of lithium or magnesium.

7. A method of passivating organic devices as claimed in claim 5 wherein the step of depositing the inorganic layer over the thermal coefficient matching layer includes depositing at least one of a layer of aluminum or indium over the layer of low work function metal.

8. A method of passivating organic devices as claimed in claim 1 wherein the step of overcoating the organic device with the layer of organic material includes overcoating the organic device with an organic polymer.

9. A method of passivating organic devices as claimed in claim 8 wherein the step of overcoating the organic device with the organic polymer includes overcoating with parylene.

10. A method of passivating organic devices as claimed in claim 1 wherein the step of overcoating the organic device with the layer of organic material includes overcoating the organic device with an organometallic complex.

11. A method of passivating organic devices as claimed in claim 10 wherein the step of overcoating the organic device with the organometallic complex includes overcoating with Alq.

12. A method of passivating organic devices as claimed in claim 1 wherein the step of sealing the organic device includes depositing a layer of epoxy encapsulant over the inorganic layer.

13. A method of passivating organic devices as claimed in claim 1 wherein the step of sealing the organic device includes applying a layer of polymer coated aluminum foil over the inorganic layer.

14. A method of passivating organic devices comprising the steps of:

providing an array of organic LEDs on a supporting substrate defining a plurality of pixels, each of the plurality of pixels including a cathode comprised of a low work function metal;

individually overcoating each of the plurality of pixels with a layer of indium;

overcoating the layer of indium of each of the plurality of pixels with a layer of one of an organic polymer or an organometallic complex;

depositing a thermal coefficient matching layer of a low work function metal on the layer of one of an organic polymer or an organometallic complex;

depositing an inorganic layer of at least one of a layer of aluminum or indium over the thermal coefficient matching layer; and

sealing the organic device with at least one of a layer of epoxy encapsulant or polymer laminated aluminum foil.

15. A passivated organic device comprising:

an organic device on a supporting substrate defining a plurality of pixels, each of the plurality of pixels including a cathode comprised of a low work function metal;

an overcoating layer of indium, individually capping the plurality of pixels;

a buffer system including an overcoating layer of organic material coating the layer of indium, individually capping the pixels;

an inorganic layer position on the buffer system; and

a sealing layer positioned on the inorganic layer.

16. A passivated organic device as claimed in claim 15 wherein the buffer system further includes a thermal coefficient matching layer positioned on the layer of organic material.

17. A passivated organic device as claimed in claim 16 wherein the thermal coefficient matching layer positioned on the layer of organic material includes a layer of low work function metal.

18. A passivated organic device as claimed in claim 16 wherein the inorganic layer includes at least one of a layer of aluminum or indium positioned over the thermal coefficient matching layer.

19. A passivated organic device as claimed in claim 16 wherein the thermal coefficient matching layer positioned on the layer of organic material includes a layer of gettering material.

22. A passivated organic device as claimed in claim 15 wherein the layer of organic material includes an organic polymer.

23. A passivated organic device as claimed in claim 22 wherein the organic polymer includes parylene.

24. A passivated organic device as claimed in claim 15 wherein the layer of organic material includes an organometallic complex.

25. A passivated organic device as claimed in claim 24 wherein the organometallic complex includes Alq.

26. A passivated organic device as claimed in claim 15 wherein the sealing layer includes a layer of epoxy encapsulant.

27. A passivated organic device as claimed in claim 15 wherein the sealing layer includes a layer of polymer laminated aluminum foil.

20. A passivated organic device as claimed in claim 20 wherein the gettering material includes a layer of low work function metal.

21. A passivated organic device as claimed in claim 20 wherein the layer of low work function metal includes one of lithium or magnesium.

28. A passivated organic device comprising:

an array of organic LEDs positioned on a supporting substrate, defining a plurality of pixels, each of the plurality of pixels including a cathode comprised of a low work function metal;

a layer of indium individually overcoating each of the plurality of pixels of the organic device;

a layer of one of an organic polymer or an organometallic complex overcoating the layer of indium;

a thermal coefficient matching layer of low work function metal positioned on the layer of one of an organic polymer or an organometallic complex;

an inorganic layer positioned on the thermal coefficient matching layer; and

a sealing layer of at least one of an epoxy encapsulant or a polymer laminated aluminum foil positioned over the inorganic layer.