O2 and h2o barrier material

• US 20040209126A1
• Filed: 11/17/2003
• Published: 10/21/2004
• Est. Priority Date: 05/04/2001
• Status: Active Grant

• Current Assignee: General Atomics, Inc.
• Original Assignee: General Atomics, Inc.
• Inventors: Ziegler, John P, Piner, John R
• Granted Patent: US 7,077,935 B2
• Time in Patent Office: Days
• US Class Current: 428/702
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/546 Flexural strength; Flexion stiffness
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 2457/206 Organic displays, e.g. OLED
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 59/874 including getter material or desiccant
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]

Abstract

O₂ and H₂O barrier materials suitable for the protection of LCDs and flexible OLEDs are fabricated on a polymer substrate using dense inorganic barrier layers. A polymer surface having a low surface roughness has an inorganic layer of aluminum or silicon oxides deposited thereupon using ion-assisted vacuum deposition with an argon ion gun, which treatment surprisingly provides a smoothing effect on the surface of the polymer. By pretreatment of prefabricated polymeric film with ion-gun enhanced plasma in the presence of oxygen, commercially available heat-stabilized PET and PEN films can be directly employed as substrates. Protective polymer layers are optionally coated upon the thin inorganic barrier layer.

Claims

1. A method of making a flexible barrier material to prevent the passage of water and oxygen to a device which incorporates organic display material, said method comprising the steps of:

providing a polymer layer;

depositing an inorganic barrier layer on the polymer layer by ion-assisted sputtering or evaporation; and

depositing a second polymer layer on said inorganic layer, whereby a composite barrier material is provided that can be associated with an electronic display device to prevent degradation of the properties thereof as a result of passage of water and/or oxygen.

2. The method of claim 1 wherein said polymer layer is a prefabricated film.

3. The method of claim 2 wherein said polymer layer is bombarded with a 50 to 250 eV oxygen or argon beam during said depositing step, that is generated using a current of between about 10 and about 1,000 milliamps.

4. The method of claim 3 wherein said deposition of said inorganic barrier layer takes place at an atmosphere of between about 0.1 to 10 millitorr and is transparent.

5. The method of claim 1 wherein said polymer layer is maintained at about a temperature not greater than about 100°

C. during said depositing of said inorganic barrier layer.

6. The method of claim 1 wherein said deposition is carried out using reactive sputtering in the presence of a partial pressure of argon and oxygen gas.

7. The method of claim 1 wherein said inorganic layer is deposited using ion-assisted thermal or electron-beam evaporation.

8. The method of claim 7 wherein said inorganic barrier layer is transparent and is deposited by reactive deposition where elemental silicon or aluminum is evaporated and an oxygen ion gun is employed for said ion assist.

9. The method of claim 1 wherein said deposition of said inorganic barrier layer is of an aluminum nitride or a silicon nitride and is performed using reactive sputtering or evaporation in the presence of a partial structure of nitrogen.

10. The method of claim 1 wherein said deposition of said inorganic barrier layer is of an aluminum oxynitride or a silicon oxynitride and is performed using reactive sputtering or evaporation with a partial pressure of oxygen and nitrogen.

11. The method of claim 1 wherein said inorganic barrier layer is transparent and contains a mixture of an inorganic oxide or nitride and a material that absorbs oxygen or water.

12. The method of claim 1 wherein said polymer layer is one that has been applied to a surface of a substrate.

13. The method of claim 1 wherein a second transparent inorganic barrier layer is deposited onto said inorganic barrier layer by interrupting deposition of said inorganic barrier layer and then resuming deposition under substantially the same conditions to create two discrete layers.

14. The improved barrier material that results from the method of claim 1.

15. The improved barrier material of claim 14 wherein the inorganic barrier layer is a transparent indium zinc oxide.

16. A method of making a flexible barrier material to prevent the passage of water and oxygen to a device which incorporates organic display material, said method comprising the steps of:

subjecting a polymer layer to pretreatment by an ion-gun-generated plasma under vacuum conditions in the presence of a partial oxygen pressure, and

depositing a transparent inorganic barrier layer on the pretreated polymer layer using ion-assisted sputtering or evaporation;

whereby a barrier material is provided that can be associated with an electronic display device to prevent degradation of the properties thereof as a result of passage of water and/or oxygen.

17. The method of claim 16 wherein said polymer layer is a prefabricated polyester film.

18. The method of claim 16 wherein said polymer layer is bombarded with a 50 to 250 eV oxygen beam during said pretreatment step for between about 1 and about 15 minutes at an oxygen atmosphere of between about 0.1 to 10 millitorr.

19. The method of claim 18 wherein a protective polymer layer is applied onto said barrier layer.

20. The method of claim 17 wherein both surfaces of said polyester film are subjected to said pretreatment step and wherein a transparent inorganic barrier layer is thereafter deposited upon each of said pretreated surfaces.

21. The method of claim 20 wherein each of said inorganic barrier layers is aluminum oxide having a thickness between about 200 and about 800 angstroms that is deposited using ion-assisted sputtering or evaporation in the presence of argon or oxygen at a pressure of not greater than 10 millitorr.

22. A method of making a flexible composite barrier material to prevent the passage of water and oxygen to an electronic display device which incorporates organic material, said method comprising the steps of:

providing a flexible polymeric substrate,

pretreating a surface of said polymeric substrate with an ion gun generated plasma in the presence of an oxygen atmosphere of between about 0.1 to about 10 millitorrs so as to provide a smoothing of said surface;

depositing a dense inorganic barrier layer which is essentially free of pinholes onto said pretreated polymeric surface by ion-assisted sputtering or evaporation; and

depositing a protective polymer layer onto said inorganic barrier layer,

whereby a composite material is provided that is useful as a base for the construction of an organic electronic display device that will withstand degradation of its properties by water and/or oxygen.