Display device and method of manufacturing a display device
A display device, which includes a plurality of unit pixels, includes a plurality of first electrodes respectively corresponding to the plurality of unit pixels, an insulating layer which includes a plurality of through holes, a light emitting element layer, and a second electrode. Each of the plurality of through holes have inner surfaces including a forwardly tapered surface, which is inclined in a direction of enlarging the apertures toward a light emitting direction, and a reversely tapered surface, which is inclined in a direction of reducing the apertures toward the light emitting direction. The forwardly tapered surface is formed between the unit pixels arranged side by side in the first direction. The reversely tapered surface is formed between the unit pixels arranged side by side in the second direction.
1. A display device, which includes a plurality of unit pixels of a plurality of colors, and is configured to display a color image, comprising:
a plurality of first electrodes respectively corresponding to the plurality of unit pixels;
an insulating layer, which includes a plurality of through holes respectively overlapping the plurality of first electrodes, and is configured to cover peripheral portions of each of the plurality of first electrodes:
a light emitting element layer, which is laminated on the insulating layer, and is connected to the plurality of first electrodes via the plurality of through holes; and
a second electrode, which is laminated on the insulating layer and the light emitting element layer,
the plurality of unit pixels being arranged so that the unit pixels of the same color are arranged in a first direction and the unit pixels of different colors are arranged side by side in a second direction, which crosses the first direction,
the insulating layer including apertures of the plurality of through holes in a surface that is opposite to the light emitting element layer,
each of the plurality of through holes having inner surfaces including a forwardly tapered surface, which is inclined in a direction of enlarging the apertures toward a light emitting direction, and a reversely tapered surface, which is inclined in a direction of reducing the apertures toward the light emitting direction,
the forwardly tapered surface being formed between the unit pixels arranged side by side in the first direction,
the reversely tapered surface being formed between the unit pixels arranged side by side in the second direction,
wherein the insulating layer has a grating shape including a plurality of first rib portions, each of the plurality of first rib portions extending in the second direction, and being arranged at intervals from each other in the first direction, and a plurality of second rib portions, each of the plurality of second rib portions extending in the first direction to connect the intervals between the first rib portions arranged side by side, and being arranged at intervals from each other in the second direction,
wherein the forwardly tapered surface comprises at least a part of a first side surface facing the first direction of each of the plurality of first rib portions, and
wherein the reversely tapered surface comprises at least a part of a second side surface facing the second direction of each of the plurality of second rib portions.
2. The display device according to claim 1 , further comprising a color filter layer including a plurality of colored regions of a plurality of colors respectively corresponding to the plurality of unit pixels.
3. The display device according to claim 2 , wherein the light emitting element layer is configured to emit light of a single color toward the plurality of colored regions.
4. The display device according to claim 1 , wherein the insulating layer is configured to have a light shielding property.
5. The display device according to claim 1 , wherein the plurality of second rib portions have an upper surface that is formed higher than an upper surface of the plurality of first rib portions in sectional view, and have a difference in height between the plurality of first rib portions and the plurality of second rib portions of equal to or less than a thickness of the second electrode.
6. The display device according to claim 5 , wherein the plurality of second rib portions and the plurality of first rib portions are connected without a step to be flush with each other.
7. The display device according to claim 1 , wherein the plurality of second rib portions have an upper surface that is formed lower than an upper surface of the plurality of first rib portions in sectional view.
8. The display device according to claim 1 , further comprising a sealing layer, which is configured to cover the plurality of first electrodes, the insulating layer, the light emitting element layer, and the second electrode,
wherein an interface between the sealing layer and a layer immediately below the sealing layer has a shape corresponding to the reversely tapered surface above the plurality of first rib portions.
9. A method of manufacturing a display device, which includes a plurality of unit pixels of a plurality of colors, and is configured to display a color image, the method comprising:
forming an insulating layer, which has a grating shape including a plurality of through holes respectively overlapping a plurality of first electrodes respectively corresponding to the plurality of unit pixels, and is configured to cover peripheral portions of each of the plurality of first electrodes;
forming a light emitting element layer, which is laminated on the insulating layer, and is connected to the plurality of first electrodes via the plurality of through holes; and
forming a second electrode, which is laminated on the insulating layer and the light emitting element layer,
the plurality of unit pixels being arranged so that the unit pixels of the same color are arranged in a first direction and the unit pixels of different colors are arranged side by side in a second direction, which crosses the first direction,
the insulating layer including apertures of the plurality of through holes in a surface that is opposite to the light emitting element layer,
each of the plurality of through holes having inner surfaces including a forwardly tapered surface, which is inclined in a direction of enlarging the apertures, and a reversely tapered surface, which is inclined in a direction of reducing the apertures,
the forming an insulating layer comprising:
forming a first photosensitive resin layer of a negative type, which has solubility that is reduced in developer by exposure to light;
patterning the first photosensitive resin layer to form a plurality of first rib portions, each of the plurality of first rib portions extending in the second direction, and being arranged side by side in the first direction among the unit pixels, to have the forwardly tapered surface in at least a part of a first side surface facing the first direction;
forming, after patterning the first photosensitive resin layer, a second photosensitive resin layer of a positive type, which has solubility that is increased in developer by exposure to light; and
patterning the second photosensitive resin layer to form a plurality of second rib portions, each of the plurality of second rib portions extending in the first direction to connect intervals between the first rib portions that are arranged side by side, and being arranged among the unit pixels that are arranged side by side in the second direction, to have the reversely tapered surface in at least a part of a second side surface facing the second direction.