Flexible substrates having a thin-film barrier

• US 20090121333A1
• Filed: 10/30/2007
• Published: 05/14/2009
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Bookbinder, Dana Craig, Aitken, Bruce Gardiner, Quesada, Mark Alejandro, Garner, Sean Matthew
• Granted Patent: US 8,115,326 B2
• Time in Patent Office: Days
• US Class Current: 257/678
• CPC Class Codes: C03C 3/122 containing oxides of As, Sb, Bi, Mo, W, V, Te as glass formers
• CPC Class Codes: C03C 3/14 containing boron
• CPC Class Codes: C03C 3/247 containing fluorine and phosphorus
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/5806 Thermal treatment
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 71/851 Division of substrate
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/239 Complete cover or casing
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/263 Coating layer not in excess of 5 mils thick or equivalent
• CPC Class Codes: Y10T 428/264 Up to 3 mils
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Methods and apparatus provide for: applying an inorganic barrier layer to at least a portion of a flexible substrate, the barrier layer being formed from a low liquidus temperature (LLT) material; and sintering the inorganic barrier layer while maintaining the flexible substrate below a critical temperature.

Claims

1. A method, comprising:

applying an inorganic barrier layer to at least a portion of a flexible substrate, the barrier layer being formed from a low liquidus temperature (LLT) material; and

sintering the inorganic barrier layer while maintaining the flexible substrate below a critical temperature thereof.

2. The method of claim 1, wherein a liquidus temperature of the barrier layer below about 1000 degrees C.

3. The method of claim 1, wherein a liquidus temperature of the barrier layer below about 600-degrees C.

4. The method of claim 1, wherein a liquidus temperature of the barrier layer below about 400 degrees C.

5. The method of claim 1, wherein the critical temperature is at least one of:

a softening temperature, a Tg temperature, and a temperature where about 10% weight loss occurs in the flexible substrate.

6. The method of claim 1, wherein the sintering step is such that at least one of pinholes, inherent porosity, and defects in the barrier layer are removed.

7. The method of claim 1, wherein the step of sintering includes controlling at least one of:

(i) a surface roughness of the inorganic barrier layer; and

(ii) a modulus of the inorganic barrier layer.

8. The method of claim 4, further comprising increasing the modulus of the inorganic barrier layer by sintering to a consolidation temperature.

9. The method of claim 1, wherein the modulus of the inorganic barrier layer is one of:

about 30 GPa to about 120 GPa, about 30 GPa to about 80 GPa., and about 30 GPa to about 50 GPa.

10. The method of claim 1, wherein the thickness of the inorganic barrier layer is one of:

less than about 10 um, less than about 5 um, and less than about 2 um.

11. The method of claim 7, further comprising sintering the inorganic barrier layer to form a modulus gradient such that the modulus at a first depth is different from the modulus at a second depth of the inorganic barrier layer.

12. The method of claim 1, wherein the step of sintering is performed by exposing the barrier layer to thermal or electromagnetic energy sources.

13. The method of claim 12, wherein the electromagnetic energy source includes at least one of UV, visible, infrared, and microwave energy.

14. The method of claim 1, wherein the flexible substrate comprises at least one of a polyimide, PEN, PET, PC, PP, OPP, PES, silicone, amorphous or crystalline polymer films, and composites.

15. The method of claim 1, wherein the inorganic barrier layer comprises at least one of a tin fluorophosphate material, chalcogenide material, phosphate material, borate material, bismuth zinc borate material, glass, CORNING Incorporated code 7070 glass, borosilicate glass., and a tellurite material.

19. The method of claim 13, wherein the thickness of the barrier layer is one of:

less than about 10 um, less than about 5 um, and less than about 2 um.

16. The method of step 1, wherein the step of applying includes utilizing a selected one or a combination of the following:

a sputtering process;

a thermal evaporation process;

an e-beam evaporation process;

a vacuum deposition process;

a spraying process;

a pouring process;

a frit-deposition process;

a vapor-deposition process;

a dip-coating process;

a painting process;

a laser-ablation process;

an electrophoretic deposition process;

a co-evaporation process;

a rolling process; and

a spin-coating process.

17. A method, comprising:

(a) computing stress in a barrier layer that has been disposed on a flexible substrate as a function of a modulus of the barrier layer, where the flexible substrate is of a given thickness, a given modulus, and a given radius of curvature;

(b) computing the stress in the barrier layer as a function of a thickness of the barrier layer;

(c) selecting a target stress for the barrier layer and determining a modulus and thickness for the barrier layer from the computation in (a)-(b);

applying the barrier layer to at least a portion of the flexible substrate; and

sintering the barrier layer while maintaining the flexible substrate below a critical temperature such that the target stress is not exceeded at the given radius of curvature.

18. The method of claim 17, wherein the modulus of the barrier layer is one of:

about 30 GPa to about 120 GPa, about 30 GPa to about 80 GPa, and about 30 GPa to about 50 GPa.

20. A method, comprising:

applying an inorganic barrier layer to at least a portion of a flexible substrate such that the inorganic barrier layer is patterned on the flexible substrate to create at least one region of the flexible substrate that is free of the inorganic barrier layer; and

sintering the inorganic barrier layer while maintaining the flexible substrate below a critical temperature.

21. The method of claim 20, further comprising cutting through the flexible substrate at the at least one region of the flexible substrate that is free of the inorganic barrier layer.

22. The method of claim 20, wherein the at least one region of the flexible substrate that is free of the inorganic barrier layer is at one or more peripheral edges of the flexible substrate.

23. An apparatus, comprising:

a flexible substrate;

an inorganic barrier layer covering at least a portion of the flexible substrate,

wherein at least one of;

(i) the modulus of the barrier layer is one of about 30 GPa to about 120 GPa, about 30 GPa to about 80 GPa, and about 30 GPa to about 50 GPa; and

(ii) the thickness of the barrier layer is one of less than about 10 um, less than about 5 um, and less than about 2 um.

24. The apparatus of claim 23, wherein a liquidus temperature of the barrier layer below about 1000 degrees C.

25. The apparatus of claim 23, wherein a liquidus temperature of the barrier layer below about 600 degrees C.

26. The apparatus of claim 23, wherein a liquidus temperature of the barrier layer below about 400 degrees C.

27. The apparatus of claim 23, further comprising:

a device disposed on the barrier layer; and

an encapsulation layer covering the device and terminating on the barrier layer, thereby forming an hermetic seal for the device.

28. The apparatus of claim 27, wherein the device is at least one of an electronic device, an optoelectronic device, an optical device, a light-emitting device, an OLED device, an organic semiconductor device, an LCD display device, a photovoltaic device, a thin-film sensor, an evanescent waveguide sensor, a food container, and a medicine container.

29. The apparatus of claim 23, wherein the flexible substrate and the inorganic barrier layer are capable of a bend radius less than at least one of:

about 20 cm, about 10 cm, and about 1 cm.

30. The apparatus of claim 23, wherein the substrate comprises least one of a, polyimide, PEN, PET, PC, PP, OPP, PES, silicone, amorphous or crystalline polymer films, or composites.

31. The device of claim 23, wherein the inorganic barrier layer comprises at least one of a tin fluorophosphate material, chalcogenide material, phosphate material, borate material, bismuth zinc borate material, glass, borosilicate glass, CORNING Incorporated code 7070 glass, and a tellurite material.

32. The apparatus of claim 23, wherein the inorganic barrier layer is patterned on the substrate.

33. The apparatus of claim 23, wherein the inorganic barrier layer does not cover an edge of the substrate.