Flexible display device and manufacturing method of the same

1. A flexible display device comprising:

a display panel including a display substrate, an organic light emitting element formed on the display substrate, and a thin film encapsulation layer covering the organic light emitting element;

a first insulation layer formed under the display panel;

a lower protection film formed under the first insulation layer; and

a reinforcement layer formed under the lower protection film, between the lower protection film and the first insulation layer, or on the display panel,

wherein the reinforcement layer is configured to prevent damage to the display panel due to bending stress and comprises an oxide semiconductor and a metal.

2. The flexible display device of claim 1 , wherein the reinforcement layer is made of an oxide semiconductor.

3. The flexible display device of claim 1 , wherein the metal is one of copper, ITO, and aluminum.

4. The flexible display device of claim 2 , wherein the oxide semiconductor is made of at least one of an oxide based on zinc, gallium, tin, or indium, or as a complex oxide thereof, including zinc oxide, indium-gallium-zinc oxide, indium-zinc oxide, or zinc-tin oxide.

5. The flexible display device of claim 1 , wherein the reinforcement layer includes a plurality of layers.

6. The flexible display device of claim 1 , wherein the reinforcement layer is formed on the display panel, and wherein the device further includes

a second insulation layer formed between the display panel and the reinforcement layer.

7. A method of manufacturing the flexible display device of claim 1 , the method comprising:

forming the first insulation layer on a supporting substrate;

forming the display panel including the display substrate positioned on the first insulation layer, the organic light emitting element formed on the display substrate, and the thin film encapsulation layer covering the organic light emitting element;

separating the supporting substrate from the first insulation layer;

forming the reinforcement layer on or under the lower protection film positioned under the display panel; and

adhering the lower protection film under the first insulation layer,

wherein the reinforcement layer is configured to prevent damage to the display panel due to bending stress.

8. The method of claim 7 , wherein the reinforcement layer is made of an oxide semiconductor.

9. The method of claim 8 , wherein the oxide semiconductor is made of one of an oxide based on zinc, gallium, tin, or indium, as a complex oxide thereof, including zinc oxide, indium-gallium-zinc oxide, indium-zinc oxide, or zinc-tin oxide.

10. A method of manufacturing the flexible display device of claim 1 , the method comprising:

forming the first insulation layer on a supporting substrate;

forming the display panel including the display substrate positioned on the first insulation layer, the organic light emitting element formed on the display substrate, and the thin film encapsulation layer covering the organic light emitting element;

forming a second insulation layer on the display panel;

forming the reinforcement layer on the second insulation layer;

separating the supporting substrate from the display panel; and

adhering the lower protection film under the display panel,

wherein the reinforcement layer prevents damage to the display panel due to bending stress.

11. The method of claim 10 , wherein the reinforcement layer is made of an oxide semiconductor.

12. The method of claim 11 , wherein the oxide semiconductor is made of one of an oxide based on zinc, gallium, tin, or indium, or as a complex oxide thereof, including zinc oxide, indium-gallium-zinc oxide, indium-zinc oxide, or zinc-tin oxide.