Multilayer device and method of making

• US 20050133781A1
• Filed: 12/19/2003
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: General Electric Company
• Inventors: Yan, Min, Duggal, Anil Raj, Schaepkens, Marc, Kim, Tae Won
• Granted Patent: US 7,075,103 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: H10K 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: Y10S 428/918 Material abnormally transparent
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

The invention relates to composite articles comprising a substrate and additional layers on the substrate. According to one example, the layers are selected so that the difference in the coefficient of thermal expansion (CTE) between the substrate and a first layer on one side of the substrate is substantially equal to the CTE difference between the substrate and a second layer on the other side of the substrate. The stress caused by the CTE difference and/or shrinkage on one side of the substrate during heating or cooling is balanced by the stress caused by the CTE difference on the other side of the substrate during heating or cooling. Such stress balancing can reduce or minimize curling of the substrate.

Claims

1. An article comprising:

a polymeric substrate having a first side and a second side;

a first layer on the first side of the polymeric substrate, the first layer having a first coefficient of thermal expansion (CTE);

a second layer on the second side of the polymeric substrate;

a third layer on the second layer, the third layer comprising a transparent conductor; and

a fourth layer on the third layer, the fourth layer comprising an organic semiconductor layer;

wherein the second layer has a second CTE which is substantially equal to the first CTE.

2. The article of claim 1, wherein the fourth layer comprises an organic electroluminescent layer.

3. The article of claim 1, wherein the fourth layer comprises an organic photovoltaic layer.

4. The article of claim 1, wherein said transparent conductor comprises a metal or a conducting oxide.

5. The article of claim 1, wherein the transparent conductor comprises indium tin oxide.

6. The article of claim 1, wherein the polymeric substrate comprises polycarbonate.

7. The article of claim 1, wherein the polymeric substrate comprises at least one of:

polyethyleneterephthalate, polyacrylate, silicone, epoxy resin, silicone-functionalized epoxy resin, polyester, polyimide, polyetherimide, polyethersulfone, polyethylenenapthalene, polynorbonene, and poly(cyclic olefin).

8. The article of claim 1, wherein the polymeric substrate comprises at least one of:

polyethyleneterephthalate, polyethelenenapthalene, polynorbonene, and poly(cyclic olefins).

9. The article of claim 1 wherein the polymeric substrate comprises a polycarbonate with a 1,3-bis(4-hydroxyphenyl)menthane repeat unit, the second and third layers comprise SiNx, and the third layer comprises indium tin oxide.

10. The article of claim 1, wherein the first and third layers each comprise at least one of:

a metal nitride, a metal oxide, and a metal oxy-nitride.

11. The article of claim 1, wherein the first and second layers comprise the same material in substantially equal amounts.

12. The article of claim 1, wherein at least one of the first layer and the second layer comprises a gas/moisture barrier coating which causes a transmission rate of oxygen through the substrate of less than about 0.1 cm³/(m² day) as measured at 25 degrees C. and with a gas containing 21 volume-percent oxygen, and a transmission rate of water vapor through the substrate of less than about 1 g/(m² day) as measured at 25 degrees C. and with a gas having 100-percent relative humidity.

13. The article of claim 1, wherein the article forms part of an electronic device.

14. An article comprising:

a composite substrate comprising a first plastic substrate, a second plastic substrate, and a layer between the first plastic substrate and the second plastic substrate, wherein the composite substrate has a first coefficient of thermal expansion (CTE); and

a transparent conductor on the composite substrate, the transparent conductor having a second CTE, wherein the first CTE is substantially equal to the second CTE.

15. The article of claim 14, wherein the composite substrate has a CTE of less than 20 ppm/K.

16. The article of claim 14, wherein the composite substrate has a CTE of less than 5 ppm/K.

17. The article of claim 14, wherein the transparent conductor comprises a metal or a conducting oxide.

18. The article of claim 14, wherein the first and second plastic substrates comprise polycarbonate.

19. The article of claim 14, wherein the layer between the first plastic substrate and the second plastic substrate comprises at least one of:

a metal nitride, a metal oxide, and a metal oxy-nitride.

20. A multilayer article comprising:

a polymeric substrate;

a first layer on one side of the polymeric substrate, the first layer having a first coefficient of thermal expansion (CTE); and

a second layer on the other side of the polymeric substrate, the second layer having a second CTE, wherein the second layer comprises a transparent conductor, and the first CTE is substantially equal to the second CTE.

21. The multilayer article of claim 20, wherein the polymeric substrate comprises polycarbonate.

22. The multilayer article of claim 20, wherein the first layer comprises SiNxOy, wherein x ranges from 0 to 2 and y ranges from 0 to 2.

23. The multilayer article of claim 20, wherein the second layer comprises a transparent conductor.

24. A method of making a multilayer article comprising the steps of:

applying a first layer on a first side of a polymeric substrate, the first layer having a first coefficient of thermal expansion (CTE);

applying a second layer on a second side of the polymeric substrate;

heating the polymeric substrate;

applying a third layer comprising a transparent conductor on the second layer;

cooling the article; and

applying a fourth layer on the third layer, the fourth layer comprising an organic semiconductor layer;

wherein the second layer has a second CTE which is substantially equal to the first CTE.

25. The method of claim 24, wherein the step of heating the substrate is carried out before applying the first and second layers.

26. The method of claim 24, wherein the step of heating the substrate is carried out after applying the first and second layers.

27. The method of claim 24, wherein the first and second layers are applied to the first substrate by one of the following methods:

plasma-enhanced chemical-vapor deposition, radio-frequency plasma-enhanced chemical-vapor deposition, expanding thermal-plasma chemical-vapor deposition, sputtering, reactive sputtering, electron-cyclotron-resonance plasma-enhanced chemical-vapor deposition, inductively-coupled plasma-enhanced chemical-vapor deposition, expanding thermal-plasma chemical-vapor deposition, and radio-frequency plasma-enhanced chemical-vapor deposition.

28. The method of claim 24, wherein the first and second layers are applied to the first substrate by at least one of:

plasma-enhanced chemical vapor deposition and sputtering.

29. The method of claim 24, wherein the fourth layer comprises an organic electroluminescent layer.

30. The method of claim 24, wherein the fourth layer comprises an organic photovoltaic layer.

31. The method of claim 24, wherein the polymeric substrate comprises polycarbonate.

32. The method claim 24, wherein the first and third layers each comprise at least one of:

a metal nitride, a metal oxide, and a metal oxy-nitride.

33. The method claim 24, wherein at least one of the first layer and the second layer comprises a gas/moisture barrier layer which causes a transmission rate of oxygen through the substrate of less than about 0.1 cm³/(m² day) as measured at 25 degrees C. and with a gas containing 21 volume-percent oxygen, and a transmission rate of water vapor through the substrate of less than about 1 g/(m² day) as measured at 25 degrees C. and with a gas having 100-percent relative humidity.

34. A method of making a multilayer article comprising:

applying a first layer on a first side of a first polymeric substrate;

applying a second polymeric substrate to the first layer, wherein the first and second polymeric substrates and the first layer comprise a composite substrate having a first coefficient of thermal expansion (CTE);

heating the substrates;

applying a second layer to a second side of the first polymeric substrate, the second layer comprising a transparent conductor and having a second CTE which is substantially equal to the first CTE; and

cooling the article.

35. The method of claim 34, wherein the first layer, the first polymeric substrate, the second polymeric substrate, and the second layer are selected such that after the cooling step, the article has a radius of curvature greater than or equal to 10 centimeters.

36. The method of claim 34, wherein the heating step occurs before the step of applying the first layer.

37. The method of claim 34, wherein the heating step occurs after the step of applying the first layer.

38. The method of claim 34, wherein:

the first layer comprises at least one of a metal nitride, a metal oxide, and a metal oxy-nitride; and

the first and second polymeric substrates comprise polycarbonate.

39. A method of making a multilayer article comprising:

applying a first layer on a first side of a polymeric substrate, the first layer having a first coefficient of thermal expansion (CTE);

heating the polymeric substrate;

applying a second layer to a second side of the polymeric substrate, the second layer comprising a transparent conductor and having a second CTE which is substantially equal to the first CTE; and

cooling the article.

40. The method of claim 39, wherein the first layer and the second layer are selected such that after the cooling step, the article has a radius of curvature greater than or equal to 10 centimeters.

41. The method of claim 39, further comprising the following additional three steps, prior to the heating step:

heating the polymeric substrate;

cooling the polymeric substrate, wherein the cooling results in significant curling of the substrate; and

storing the resulting article comprising the first layer and the first substrate.

42. The method of claim 39, wherein the heating step occurs before the step of applying the first layer.

43. The method of claim 39, wherein the polymeric substrate comprises polycarbonate and the first layer comprises SiNxOy, wherein x ranges from 0 to 2 and y ranges from 0 to 2.