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US-20260130060-A1 - DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF

US20260130060A1US 20260130060 A1US20260130060 A1US 20260130060A1US-20260130060-A1

Abstract

According to one embodiment, a display device includes a lower electrode, a rib covering a part of the lower electrode and including a pixel aperture, a partition surrounds the pixel aperture, an upper electrode facing the lower electrode, and an organic layer between the lower and upper electrodes. The partition includes a conductive lower portion including an annular side surface which surrounds the pixel aperture, and an upper portion including an annular protrusion which protrudes from the side surface. The upper electrode is in contact with the side surface of the lower portion. The protrusion has a constant width over a whole circumference.

Inventors

  • Arichika Ishida

Assignees

  • MAGNOLIA WHITE CORPORATION

Dates

Publication Date
20260507
Application Date
20251229
Priority Date
20220510

Claims (7)

  1. 1 . A display device comprising: a lower electrode; a rib which covers a part of the lower electrode and comprises a pixel aperture overlapping the lower electrode; a partition which is provided on the rib and surrounds the pixel aperture; an upper electrode which faces the lower electrode; and an organic layer which is provided between the lower electrode and the upper electrode and emits light based on a potential difference between the lower electrode and the upper electrode, wherein the partition includes: a conductive lower portion comprising an annular side surface which surrounds the pixel aperture; and an upper portion comprising an annular protrusion which protrudes from the side surface, the upper electrode is in contact with the side surface of the lower portion, and an inner peripheral portion of the partition surrounding the pixel aperture comprises, as seen in plan view, a plurality of first linear portions, and a first corner portion connecting adjacent two first linear portions of the plurality of first linear portions, in the first linear portions, the side surface and an end portion of the protrusion linearly extend, and in the first corner portion, the side surface and the end portion of the protrusion arcuately extend.
  2. 2 . The display device of claim 1 , wherein a curvature of the end portion of the protrusion in the first corner portion is greater than a curvature of the side surface in the first corner portion.
  3. 3 . The display device of claim 2 , wherein the pixel aperture comprises, as seen in plan view, a plurality of second linear portions parallel to the first linear portions, respectively, and a second corner portion connecting adjacent two second linear portions of the plurality of second linear portions, and the curvature of the end portion of the protrusion in the first corner portion is less than a curvature of the pixel aperture in the second corner portion.
  4. 4 . The display device of claim 1 , wherein in each of the first linear portions and the first corner portion, part of the organic layer covers an upper surface of the protrusion.
  5. 5 . The display device of claim 1 , further comprising: a cap layer which covers the upper electrode; and a sealing layer which covers the cap layer, and continuously covers the side surface and the protrusion in each of the first linear portions and the first corner portion.
  6. 6 . The display device of claim 1 , wherein the upper portion is thinner than the lower portion.
  7. 7 . The display device of claim 1 , wherein a width of the protrusion in the first corner portion is substantially equal to that of the protrusion in the first linear portions.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application No. Ser. No. 18/299,081, filed Apr. 12, 2023, which is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-077460, filed May 10, 2022, the entire contents of each are incorporated herein by reference. FIELD Embodiments described herein relate generally to a display device and a manufacturing method thereof. BACKGROUND Recently, display devices to which an organic light emitting diode (OLED) is applied as a display element have been put into practical use. This display element comprises a lower electrode, an organic layer which covers the lower electrode, and an upper electrode which covers the organic layer. When such a display device is manufactured, a technique which prevents the reduction in reliability is required. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration example of a display device according to an embodiment. FIG. 2 is a diagram showing an example of the layout of subpixels. FIG. 3 is a schematic cross-sectional view of the display device along the III-III line of FIG. 2. FIG. 4 is a diagram showing an example of a structure which could be applied to a partition and its vicinity. FIG. 5 is a schematic plan view showing the shape of the partition which surrounds a first subpixel. FIG. 6 is a schematic plan view in which the vicinity of a corner portion of the partition is enlarged. FIG. 7 is a schematic cross-sectional view showing part of the manufacturing process of the display device according to the embodiment. FIG. 8 is a schematic cross-sectional view showing a process following FIG. 7. FIG. 9 is a schematic cross-sectional view showing a process following FIG. 8. FIG. 10 is a schematic cross-sectional view showing a process following FIG. 9. FIG. 11 is a schematic cross-sectional view showing a process following FIG. 10. FIG. 12 is a schematic cross-sectional view showing a process following FIG. 11. FIG. 13 is a schematic cross-sectional view showing a process following FIG. 12. FIG. 14 is a schematic cross-sectional view showing a process following FIG. 13. FIG. 15 is a schematic cross-sectional view showing a process following FIG. 14. FIG. 16 is a schematic cross-sectional view showing a process following FIG. 15. FIG. 17 is a schematic cross-sectional view showing a process following FIG. 16. FIG. 18 is a diagram showing a comparative example of the embodiment. DETAILED DESCRIPTION In general, according to one embodiment, a display device comprises a lower electrode, a rib which covers a part of the lower electrode and comprises a pixel aperture overlapping the lower electrode, a partition which is provided on the rib and surrounds the pixel aperture, an upper electrode which faces the lower electrode, and an organic layer which is provided between the lower electrode and the upper electrode and emits light based on a potential difference between the lower electrode and the upper electrode. The partition includes a conductive lower portion comprising an annular side surface which surrounds the pixel aperture, and an upper portion comprising an annular protrusion which protrudes from the side surface. The upper electrode is in contact with the side surface of the lower portion. The protrusion has a constant width over a whole circumference. According to another embodiment, a manufacturing method of a display device includes forming a lower electrode above a substrate, forming a rib which covers at least part of the lower electrode, forming a metal layer which is a base of a lower portion of a partition on the rib, forming a thin film which is a base of an upper portion of the partition on the metal layer, forming a resist on the thin film, forming the upper portion by removing, of the thin film, a portion exposed from the resist by etching, and forming the lower portion and an annular protrusion having a constant width over a whole circumference by removing, of the metal layer, a portion exposed from the resist by etching and reducing a width of, of the metal layer, a portion located under the resist. The embodiments can provide a display device in which the reliability can be improved and a manufacturing method thereof. Embodiments will be described with reference to the accompanying drawings. The disclosure is merely an example, and proper changes in keeping with the spirit of the invention, which are easily conceivable by a person of ordinary skill in the art, come within the scope of the invention as a matter of course. In addition, in some cases, in order to make the description clearer, the widths, thicknesses, shapes, etc., of the respective parts are illustrated schematically in the drawings, rather than as an accurate representation of what is implemented. However, such schematic illustration is merely exemplary, and in no way restricts the interpretation of the invention. In addition, in the specification and drawings