Transparent conductive articles and methods of making same

Abstract

A lightweight, flexible, plastic substrate used to construct displays, including flat panel displays, to package materials and for electro luminescence lamps is coated with at least one layer, such that the substrate has desired barrier and electrode characteristics. The display medium of the flat panel display is protected from oxygen and moisture in order to avoid degradation with the coating. The layer with barrier and electrode characteristics has both a low enough resistance to function as an electrode for the display, and low oxygen and moisture permeability. For lower permeability and / or higher conductivity, multiple alternating layers of barrier materials and conductive materials are applied. The barrier material includes at least one of a thin metallic film, an organic polymer, a thin transparent dielectric, a thin transparent metal nitride, and a thin transparent conductive oxide. The conductive material includes at least one of a thin transparent conductive oxide, a thin transparent metallic film, and a thin transparent metal nitride. Preferably there is a Polymer Multi Layer (PML) processed base coat deposited over the substrate. The base coat produces substrate smoothing, and more importantly, in combination with another layer, the base coat improves vapor barrier properties. In the preferred embodiment, a PML processed top coat barrier layer is deposited before the coating contacts a surface, such as a roller. The PML processed top coat also excludes moisture (water vapor) and atmospheric gases that chemically degrade the device performance.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. patent application Ser. No. 10 / 317623, which is a Continuation of U.S. patent application Ser. No. 09 / 939008, filed Aug. 24, 2001, which is a Divisional Application of U.S. application Ser. No. 09 / 419870, filed Oct. 18, 1999, now abandoned, which claims the benefit of U.S. Provisional Application No. 60 / 106871, filed Nov. 2, 1998, all of which are incorporated by reference, including the original specification, first substitute specification, second substitute specification, and all attached Appendices of U.S. application Ser. No. 09 / 419870.FIELD OF THE INVENTION [0002] This invention relates to composite substrates for flat panel displays (FPD), packaging materials and light sources (electro luminescence lamps) comprising a plastic substrate having thin film barrier and conductive layers,in particular, multiple thin alternating layers of metallic film, transparent conductive oxide (TCO), meta...

AI Technical Summary

Benefits of technology

[0005] The present invention is directed to the fabrication of flat panel displays on lightweight, flexible, plastic substrates. Because plastic substrates for FPDs are flexible, smaller and lighter than glass substrates, the electronic device with the plastic FPD is more portable, space-efficient and lightweight. In addition, electroluminescent and organic light emitting devices fabricated on flexible polymeric substrates in a coating process have lower manufacturing costs than those with glass substrates, and improved ruggedness.

[0007] Using a smoothing base coat layer over the plastic substrate imparts good optical quality throughout the substrate layers and provides a pristine surface for nucleation of the deposited barrier or conductive layer, e.g. TCO. The pristine surface smooths over any surface roughness of the plastic substrate, thereby adding to the FPD lifetime and optical quality. Additionally, a hardcoat layer is applied over the substrate in lieu of or in addition to the smoothing basecoat layer.

[0011] The PML deposited organic polymer layer is used to produce substrate surface smoothing and improve barrier coatings in the multilayer structure. The benefit of a smooth substrate surface is that there is a clean surface for adhesion, nucleation, and growth of a deposited barrier or conductive layer, e.g. a TCO. Additionally, a PML deposited organic polymer layer provides protection of an underlying barrier layer in order to minimize holes or other defects in the layer so that there is low permeability.

[0013] In an embodiment, a PML processed top coat polymer layer is applied before the previously deposited layer contacts a surface, such as a roller, thereby protecting the previously deposited layer. The PML processed top coat greatly enhances the exclusion of moisture (water vapor) and atmospheric gases that chemically degrade the display medium and decrease the device performance, even though the polymer topcoat is not, itself, a good barrier material.

[0016] The thin layers of TCO are preferably deposited in combination with layers from the PML process, which leads to improved optical, electrical and mechanical performance. In particular, the polymer layers separate the TCO layers. Superior surface properties (low surface roughness, and high optical quality), barrier properties (low vapor permeability) and mechanical properties result when TCO coatings are deposited by magnetron sputtering on a plastic substrate in combination with the PML process.

Problems solved by technology

In particular, the layer has both low oxygen and water vapor permeability, and a low enough resistivity to function as an electrode for the display.

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