Hitachi Displays, Ltd.

Panasonic Liquid Crystal Display Co., Ltd.

Naoyuki Ito

Masaaki Okunaka

Kazuhiko Kai

An organic EL display device includes a substrate, pixel regions, each having a first electrode, a light emitting material layer, and a second electrode, and a bank film formed by a laminated structure of a plurality of inorganic material films having different etching rates from one another formed above the substrate to separate pixel regions from one another. The bank film has openings exposing upper surfaces of the first electrodes to the light emitting material layers, and the second electrode is formed over the openings in common with the pixel regions. A side wall of the bank film around the openings thereof is sloped at an angle 10 to 85 degrees (&#xb0;) with respect to a principal surface of the substrate to prevent deterioration of the light emitting material layer and disconnection of the second electrode at steps of the bank film in the vicinity of the openings.

Organic EL display device comprising moisture diffusion reduction banks structure

In an organic EL display device comprising a substrate, a plurality of pixel regions in each of which a first electrode, a light emitting material layer, and a second electrode are laminated in this order above the substrate, and a bank film formed above the substrate to separate respective one of the pixel regions from another of the pixel regions adjacent thereto, wherein the bank film has a plurality of openings exposing upper surfaces of the first electrodes to the light emitting material layers in the respective pixel regions, and the second electrode is formed over the a plurality of openings of the bank film in common with the pixel regions, the present invention forms the bank film of an inorganic material and shapes a side wall thereof lying around each of the openings thereof to be sloped at an angle less than 85 degrees (&#xb0;) with respect to a principal surface of the substrate in order to prevent the deterioration of the light emitting material layer and disconnection of the second electrode at steps of bank film lying in the vicinity of the openings thereof.

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Chiba, Japan

Naoyuki Ito