Methods for Attaching Flexible Substrates to Rigid Carriers and Resulting Devices

• US 20110311789A1
• Filed: 09/10/2009
• Published: 12/22/2011
• Est. Priority Date: 09/12/2008
• Status: Abandoned Application

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Loy, Douglas E., O'Rourke, Shawn M.
• Application Number:
  US13/062,020
• Publication Number:
  US 20110311789A1
• Time in Patent Office: Days
• US Class Current: 428/198
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/6835 used as a support during build up manufacturing of active devices
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 3/007 Manufacture or processing of a substrate for a printed circuit board supported by a temporary or sacrificial carrier H05K1/187, H05K3/20 and H05K3/4682 take precedence
• CPC Class Codes: H05K 3/341 Surface mounted components
• CPC Class Codes: Y10T 428/24826 Spot bonds connect components

Abstract

Flexible substrates can be temporarily attached to a rigid carrier for processing a surface thereof by depositing a joining material at one or more contact points between a flexible substrate and a rigid carrier, contacting the flexible substrate and the rigid carrier at the one or more contact points; and exposing the one or more contact points to a temperature of between 219° C. and 1000° C. and under conditions suitable for attaching the flexible substrate and the rigid carrier at the one or more contact points via the joining material. Examples of suitable joining materials include, but are not limited to soldering or brazing materials. Such supported substrates can be used for preparing flexible displays comprising at least one electronic component and/or circuit on a surface of the flexible display.

Claims

1. A method for attaching a flexible substrate to a rigid carrier, comprising

(a) depositing a joining material at one or more contact points between a flexible substrate and a rigid carrier;

(b) contacting the flexible substrate and the rigid carrier at the one or more contact points; and

(c) exposing the one or more contact points to a temperature of between 219°

C. and 1000°

C. and under conditions suitable for attaching the flexible substrate and the rigid carrier at the one or more contact points via the joining material.

2. The method of claim 1 wherein the joining material comprises soldering or brazing material.

4. The method of claim 1 wherein the one or more contact points have a thickness of between 2 μ

m and 100 μ

m.

5. The method of claim 1 wherein the one or more contact points have a width of between 100 μ

m and 4 mm.

7. The method of claim 1 wherein the conditions comprise applying a force of between 5 and 40 kN to the one or more contact points between the flexible substrate and the rigid carrier prior to or simultaneously with exposing the one or more contact points to a temperature of between 219°

C. and 1000°

C.

11. The method of claim 1 wherein the flexible substrate is a plastic substrate or metal substrate.

14. The method of claim 1 wherein the rigid support comprises a semiconductor wafer, alumina, a glass, or a material coefficient of thermal expansion (CTE) matched to the flexible substrate.

3. (canceled)

6. (canceled)

8-10. -10. (canceled)

12-13. -13. (canceled)

15-17. -17. (canceled)

18. An assembly comprising:

(a) a flexible substrate;

(b) a rigid carrier; and

(c) a plurality of discrete contact points between the flexible substrate and the rigid carrier,

wherein the contact points comprise a joining material with a melting temperature between 219°

C. and 1000°

C., and wherein the flexible substrate and the rigid carrier have a melting temperature greater that the melting temperature of the joining material.

20. The assembly of claim 18 wherein the plurality of discrete contact points have a thickness of between 2 μ

m and 100 μ

m.

21. The assembly of claim 18 wherein the plurality of discrete contact points have a width of between 100 μ

m and 4 mm.

22. The assembly of claim 18 wherein the joining material is selected from the group consisting of SnAgCu alloys, SnZn alloys, Ni/Ag alloys, Cu/Zn alloys, SnCuSb Ag alloys, ZnAl alloys, and Cu/Ag alloys.

23. The assembly of claim 18 wherein the flexible substrate is a plastic substrate or metal substrate.

26. The assembly of claim 18 wherein the rigid support comprises a semiconductor wafer, alumina, a glass, or a material CTE matched to the flexible substrate.

28. The assembly of claim 18 wherein the flexible substrate comprises at least one electronic component and/or circuit on a surface of the flexible substrate.

29. The assembly of claim 18 further comprising a display architecture on the flexible substrate.

19. (canceled)

24-25. -25. (canceled)

27. (canceled)

30. (canceled)

31. An assembly, comprising

(a) a flexible substrate;

(b) a rigid carrier; and

(c) a joining material at one or more contact points between the flexible substrate and the rigid carrier,

wherein the joining material has a melting temperature between 219°

C. and 1000°

C., and wherein the flexible substrate and the rigid carrier have a melting temperature greater that the melting temperature of the joining material, and wherein the assembly has a bow of less than 150 μ

m.

33. The assembly of claim 31 wherein the one or more contact points have a thickness of between 2 μ

m and 100 μ

m.

34. The assembly of claim 31 wherein the one or more contact points has a width of between 100 μ

m and 4 mm.

35. The assembly of claim 31 wherein the joining material is selected from the group consisting of SnAgCu alloys, SnZn alloys, Ni/Ag alloys, Cu/Zn alloys, SnCuSb Ag alloys, ZnAl alloys, and Cu/Ag alloys.

36. The assembly of claim 31 wherein the flexible substrate is a plastic substrate or metal substrate.

39. The assembly of claim 31 wherein the rigid support comprises a semiconductor wafer, alumina, a glass, or a material coefficient of thermal expansion (CTE) matched to the flexible substrate.

43. The assembly of claim 31 further comprising one or more thin film transistors, organic light emitting diodes, inorganic light emitting diodes, electrode arrays, field effect transistors, passive structures, photovoltaic devices, or combinations thereof on a surface of the flexible substrate.

32. (canceled)

37-38. -38. (canceled)

40-42. -42. (canceled)

44. A method for attaching a plastic flexible substrate to a rigid carrier, comprising

(a) depositing a joining material on a surface of the rigid carrier at one or more contact points between the plastic flexible substrate and a rigid carrier;

(b) aligning a metalized surface of the plastic flexible substrate and the joining material on the surface of the rigid carrier surface, wherein the metallization is present on a surface of the flexible substrate at the one or more contact points;

(c) contacting the plastic flexible substrate and the rigid carrier at the one or more contact points; and

(d) exposing the one or more contact points to a temperature of between 219°

C. and 1000°

C. and under conditions suitable for attaching the plastic flexible substrate and the rigid carrier at the one or more contact points via the joining material.

45. The method of claim 44 wherein the joining material comprises soldering or brazing material.

47. The method of claim 44 wherein the one or more contact points have a thickness of between 2 μ

m and 100 μ

m.

48. The method of claim 44 wherein the one or more contact points have a width of between 100 μ

m and 4 mm.

49. The method of claim 44 where exposing the one or more contact points to a temperature of between 219°

C. and 1000°

C. is done under vacuum.

50. The method of claim 44 wherein the conditions comprise applying a force of between 5 and 40 kN to the one or more contact points between the plastic flexible substrate and the rigid carrier prior to or simultaneously with exposing the one or more contact points to a temperature of between 219°

C. and 1000°

C.

55. The method of claim 44 wherein the rigid support comprises a semiconductor wafer, alumina, a glass, or a material coefficient of thermal expansion (CTE) matched to the plastic flexible substrate.

46. (canceled)

51-54. -54. (canceled)

56-58. -58. (canceled)