Compositions and processes for format flexible, roll-to-roll manufacturing of electrophoretic displays

• US 20040045830A1
• Filed: 04/23/2003
• Published: 03/11/2004
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: E Ink California, LLC (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Wu, Zarng-Arh George, Liang, Rong-Chang, Wang, Xiaojia, Tseng, Scott C-J
• Granted Patent: US 6,873,452 B2
• Time in Patent Office: Days
• US Class Current: 204/600
• CPC Class Codes: G02F 1/094 based on magnetophoretic effect
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1681 having two or more microcells partitioned by walls, e.g. of microcup type

Abstract

The present invention is directed to a process which comprises removing and stripping off part of the display panel in order to expose and connect the conductor lines on an electrode plate to a driver circuitry. More specifically the process involves (1) preparing a display panel having filled display cells sandwiched between a first and a second substrate layers, preferably by a roll-to-roll process; (2) removing part of a first substrate by asymmetrical cutting by, for example, a die, diamond, knife or laser cutting method to expose the layers underneath (which may include adhesive layer, primer layer, display cell layer and in the case of a display prepared by the microcup technology, the microcup layer and the sealing layer); and (3) stripping off the exposed layers by a stripping solvent or solution. After stripping, the conductor lines on the second substrate are exposed and ready for connection to the driver circuitry.

Claims

1. A process for manufacturing an electrophoretic display comprising display cells sandwiched between a first electrode layer and a second electrode layer, which process comprises removing part of the first electrode layer and stripping off the display cell layer underneath to expose the conductor lines on the second electrode layer for connection to a driver circuitry.

42. A roll-to-roll process for the manufacture of an electrophoretic display which process comprises the process of claim 1 without the strip or patch coating/embossing process.

44. A process for the manufacture of an electrophoretic display which process comprises the process of claim 1 and the strip or patch coating/embossing process.

2. A process for manufacturing an electrophoretic display comprising a first electrode layer and a second electrode layer, a layer of display cells sandwiched between said two electrode layers;

and optionally a strippable adhesive layer between one of said electrode layers and said display cell layer, which process comprises;

a) removing the first electrode layer in a predetermined area;

b) stripping off said adhesive layer if present and display cell layer in the predetermined area to expose the second electrode layer thereunder; and

c) connecting the exposed conductor lines or patterns on the second electrode layer to a driver circuitry.

3. The process of claim 2, further comprising applying a protective coating or edge seal to protect areas not to be stripped, before step (b).

4. The process of claim 2 wherein said first electrode layer in the predetermined area is removed by die cutting, diamond cutting, knife cutting or laser cutting.

5. The process of claim 2 wherein said strippable adhesive layer is formed from one adhesive or a mixture of adhesives selected from a group consisting of pressure sensitive, hot melt and radiation curable adhesives.

6. The process of claim 5 wherein said strippable adhesive layer comprises a multifunctional acrylate and a solvent soluble or dispersible polymer or oligomer.

7. The process of claim 6 wherein said solvent soluble or dispersible polymer or oligomer is selected from a group consisting of polyester, polyvinyl butyral, acrylic or methacrylic copolymers, styrene copolymers, polycaprolactone, polyethers, polycarbonate, polyamides and polyurethane.

8. The process of claim 5 wherein said strippable adhesive layer comprises a multifunctional acrylate and a water soluble or dispersible polymer or oligomer.

9. The process of claim 8 wherein said water soluble or dispersible polymer or oligomer is selected from a group consisting of polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinylpyrrolidone, hydroxyethyl cellulose, hydroxypropyl cellulose, and their copolymers or block copolymers, acidic or basic copolymers derived from acrylic acid or methacrylic acid, itaconic acid, maleic anhydride, vinyl phthalate and vinylpyridine.

10. The process of claim 2 wherein said adhesive layer if present and display cell layer in the predetermined area where the first electrode layer has been removed are stripped off by a stripping solvent.

11. The process of claim 3 wherein said adhesive layer if present and display cell layer in the unprotected area are stripped off by a stripping solvent.

12. The process of claim 10 wherein said stripping solvent is selected from a group consisting of benzyl alcohol, isopropyl acetate, butyl acetate, methoxyethanol, butanol, toluene, xylene, cyclohexanone or ketones, lactones, esters, ethers, alcohols, amides, pyrrolidones and their derivatives or mixtures.

13. The process of claim 10 wherein said stripping solvent is an aqueous stripper.

14. The process of claim 13 wherein said aqueous stripper is aqueous developer Shipley 453 or CD26.

15. The process of claim 2 wherein the stripping of said adhesive layer if present and display cell layer comprises a step of using a nozzle or compressed air, a soft brush or other mechanical or physical means to assist stripping.

16. The process of claim 3 wherein said protective coating or edge seal material is a highly crosslinked polymer.

17. The process of claim 16 wherein said highly crosslinked polymer is selected from a group comprising epoxy resins, polyurethanes and radiation cured multifunctional acrylates and vinyls.

18. A process for manufacturing an electrophoretic display comprising a first electrode layer and a second electrode layer, a layer of display cells sandwiched between said two electrode layers and said display cells are sealed with a sealing layer, optionally a primer layer between the display cell layer and the second electrode layer and further optionally an adhesive layer between the display cell layer and the first electrode layer, which process comprises:

a) removing the first electrode layer in a predetermined area;

b) stripping off said adhesive layer if present, display cell layer, sealing layer and primer layer if present in the predetermined area to expose the second electrode layer thereunder; and

c) connecting the exposed conductor lines or patterns on the second electrode to a driver circuitry.

19. The process of claim 18, further comprising applying a protective coating or edge seal to protect areas not to be stripped, before step (b).

20. The process of claim 18 wherein said first electrode layer in the predetermined area is removed by die cutting, knife cutting, diamond cutting, or laser cutting.

21. The process of claim 18 wherein said strippable adhesive layer is formed from one adhesive or a mixture of adhesives selected from a group consisting of pressure sensitive, hot melt and radiation curable adhesives.

22. The process of claim 21 wherein said strippable adhesive layer comprises a multifunctional acrylate and a solvent soluble or dispersible polymer or oligomer.

23. The process of claim 22 wherein said solvent soluble or dispersible polymer or oligomer is selected from a group consisting of polyester, polyvinyl butyral, acrylic or methacrylic copolymers, styrene copolymers, polycaprolactone, polyethers, polycarbonate, polyamides and polyurethane.

24. The process of claim 21 wherein said strippable adhesive layer comprises a multifunctional acrylate and a water soluble or dispersible polymer or oligomer.

25. The process of claim 24 wherein said water soluble or dispersible polymer or oligomer is selected from a group consisting of polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl pyrrolidone, hydroxyethyl cellulose, hydroxypropyl cellulose, and their copolymers or block copolymers, acidic or basic copolymers derived from acrylic acid or methacrylic acid, itaconic acid, maleic anhydride, vinyl phthalate and vinylpyridine.

26. The process of claim 18 wherein said adhesive layer if present, display cell layer, sealing layer and primer layer if present in the predetermined area where the first electrode layer has been removed are stripped off by a stripping solvent.

27. The process of claim 19 wherein said adhesive layer if present, display cell layer, sealing layer and primer layer if present in the unprotected area are stripped off by a stripping solvent.

28. The process of claim 27 wherein said stripping solvent is selected from a group consisting of benzyl alcohol, isopropyl acetate, butyl acetate, methoxyethanol, butanol, toluene, xylene, cyclohexanone or ketones, lactones, esters, ethers, alcohols, amides, pyrrolidones and their derivatives or mixtures.

29. The process of claim 27 wherein said stripping solvent is an aqueous stripper.

30. The process of claim 29 wherein said aqueous stripper is aqueous developer Shipley 453 or CD26.

31. The process of claim 18 wherein the stripping of said adhesive layer if present, display cell layer, sealing layer and primer layer if present comprises a step of using a nozzle or compressed air, a soft brush or other mechanical or physical means to assist stripping.

32. The process of claim 19 wherein said protective coating or edge seal material is a highly crosslinked polymer.

33. The process of claim 32 wherein said highly crosslinked polymer is selected from a group consisting of epoxy resins, polyurethanes and radiation cured multifunctional acrylates and vinyls.

34. A process for manufacturing an electromagnetophoretic display comprising display cells sandwiched between a substrate layer and an electrode layer, which process comprises removing part of the substrate layer and stripping off the display cell layer underneath to expose the conductor lines on the electrode layer for connection to a driver circuitry.

43. A roll-to-roll process for the manufacture of an electromagnetophoretic display which process comprises the process of claim 34 without the strip or patch coating/embossing process.

45. A process for the manufacture of an electromagnetophoretic display which process comprises the process of claim 34 and the strip or patch coating/embossing process.

35. A process for manufacturing an electromagnetophoretic display comprising a substrate layer and an electrode layer, a layer of display cells sandwiched between the two layers;

and optionally a strippable adhesive layer between one of the two layers and said display cell layer, which process comprises;

a) removing the substrate layer in a predetermined area;

b) stripping off said adhesive layer if present and display cell layer in the predetermined area to expose the electrode layer thereunder; and

c) connecting the exposed conductor lines or patterns on the electrode to a driver circuitry.

36. The process of claim 35 further comprising applying a protecting coating or edge seal to protect areas not to be stripped, before step (b).

37. A process for manufacturing an electromagnetophoretic display comprising a substrate layer and an electrode layer, a layer of display cells sandwiched between said two layers and said display cells are sealed with a sealing layer, optionally a primer layer between the display cell layer and the second electrode layer and further optionally an adhesive layer between the display cell layer and the substrate layer, which process comprises:

a) removing the first electrode layer in a predetermined area;

b) stripping off said adhesive layer if present, display cell layer, sealing layer and primer layer if present in the predetermined area to expose the electrode layer thereunder; and

c) connecting the exposed conductor lines or patterns on the electrode to a driver circuitry.

38. The process of claim 37 further comprising applying a protecting coating or edge seal to protect areas not to be stripped, before step (b).

39. A composition for strippable sealing and adhesive layers useful in the preparation of an electrophoretic or electromagnetophoretic display, which composition comprises a solvent and a rubber material selected from the group consisting of thermoplastic elastomers, polyvalent acrylate or methacrylate, cyanoacrylates, polyvalent vinyl including vinylbenzene, vinylsilane, vinylether, polyvalent epoxide, polyvalent isocyanate, polyvalent allyl and oligomers or polymers containing crosslinkable functional groups.

40. The composition of claim 39 further comprising an additive.

41. The composition of claim 40 wherein said additive is a polymeric binder or thickener, photoinitiator, catalyst, filler, colorant or surfactant.