Display device having an undercut structure in a non-display area
A display device includes: a substrate having a display area and a non-display area; a lower connection line disposed in the non-display area; a bank layer disposed on the lower connection line and having an undercut structure at an edge of a lower end portion thereof; a bank etch layer disposed between the lower connection line and the bank layer and having an edge inside the edge of the lower end portion of the bank layer; and a second driving electrode disposed on the bank layer and electrically connected to the lower connection line at least once, wherein a plurality of bank holes are formed in the bank layer.
1. A display device, comprising:
a substrate having a display area and a non-display area;
a lower connection line disposed in the non-display area;
a bank layer disposed on the lower connection line in the non-display area;
a bank etch layer disposed between the lower connection line and the bank layer in the non-display area such that the bank etch layer is farther from the substrate than the lower connection line, the bank etch layer having an edge that is inset from an edge of a lower end portion of the bank layer such that an undercut structure is located between the edge of the lower end portion of the bank layer that extends beyond the edge of the bank etch layer and a portion of the lower connection line that overlaps the edge of the lower end portion of the bank layer; and
a second driving electrode disposed on the bank layer in the non-display area, the second driving electrode electrically connected to the lower connection line at least once in the non-display area via a plurality of bank holes in the bank layer.
2. The display device of claim 1 , wherein the second driving electrode is disposed to be spaced apart from the bank etch layer.
3. The display device of claim 1 , wherein the bank layer includes a bank open portion in an emission part of the display area, and the plurality of bank holes are disposed more densely as compared with the bank open portion.
4. The display device of claim 3 , wherein at least one of the plurality of bank holes is formed to be ⅓ to ⅕ smaller than the bank open portion.
5. The display device of claim 1 , wherein an edge of the bank etch layer disposed in the display area is more inset from an edge of a lower end portion of the bank layer in the display area than the edge of the bank etch layer disposed in the non-display area with respect to the lower end portion of the bank layer in the non-display area.
6. The display device of claim 1 , wherein the bank etch layer is formed as an inorganic insulating film.
7. The display device of claim 6 , wherein the inorganic insulating film includes at least one selected from among silicon nitride, silicon oxide, or silicon oxynitride.
8. The display device of claim 1 , further comprising:
a plurality of subpixels disposed in the display area;
a first driving electrode provided for each of the plurality of subpixels and made of a same material as the lower connection line; and
a hole injection layer disposed on the first driving electrode and the bank layer,
wherein the hole injection layer is divided and disposed at the edge of the bank layer.
9. The display device of claim 8 , wherein the hole injection layer is disposed to be spaced apart from the first driving electrode.
10. The display device of claim 8 , wherein a thickness of the bank etch layer is greater than or equal to a thickness of the hole injection layer.
11. The display device of claim 8 , wherein a lower end portion of the bank layer is vertically spaced apart from an upper portion of the first driving electrode.
12. The display device of claim 8 , wherein the hole injection layer is separated into a portion formed on the first driving electrode and a portion formed on the bank layer due to a shape of the bank etch layer, thereby allowing the hole injection layer to be separated for each subpixel.
13. The display device of claim 8 , wherein the bank layer includes a bank open portion in the display area and the plurality of bank holes in the non-display area,
wherein a size of the bank open portion is greater than a size of each of the plurality of bank holes such that the hole injection layer on the first driving electrode is divided from the hole injection layer on the bank layer and the second driving electrode on the lower connection line is connected to the second driving electrode of the bank layer.
14. The display device of claim 1 , wherein an interval between the plurality of bank holes is ⅓ to ⅕ smaller as compared with an interval between the bank layer of the display area.
15. The display device of claim 1 , wherein the bank layer is made of a material having an etch rate different from an etch rate of the bank etch layer.
16. The display device of claim 1 , wherein a top surface of the lower connection line, a side surface of the edge of the bank etch layer, a bottom surface of the edge of the lower end portion of the bank layer and a bottom surface of the second driving electrode constitute a void.
17. A display device comprising:
a substrate which has a display area including a plurality of subpixels and a non-display area outside the display area;
a plurality of first driving electrodes in the display area, each first driving electrode provided for a corresponding one of the plurality of subpixels;
a lower connection line in the non-display area, the lower connection line made of a same material as the plurality of first driving electrodes;
a bank layer having a first bank layer portion disposed on the plurality of first driving electrodes in the display area and a second bank layer portion on the lower connection line in the non-display area;
a second driving electrode that is disposed on the first bank layer portion in the display area and the second bank layer portion in the non-display area, the second driving electrode spaced apart from the first driving electrode, and connected to the lower connection line at least once in the non-display area; and
a bank etch layer disposed between the lower connection line and the second bank layer portion in the non-display area such that an upper surface of the bank etch layer is covered by the second bank layer portion in the non-display area, the bank etch layer having an edge that is inset from an edge of a lower end portion of the second bank layer portion in the non-display area such that an undercut structure is located between the edge of the lower end portion of the second bank layer portion that extends beyond the edge of the bank etch layer and a portion of the lower connection line that overlaps the edge of the lower end portion of the bank layer,
wherein the second driving electrode is in contact with a side portion of the bank layer.
18. The display device of claim 17 , wherein the non-display area includes:
a first area in contact with the display area to transmit a signal from a gate driver to the display area;
a second area in which the gate driver is disposed;
a third area and a fourth area in which a power supply line for supplying power to the second driving electrode is disposed;
a fifth area in which an end of an encapsulation layer configured to reduce permeation of oxygen or moisture is disposed; and
a sixth area in which a crack detector is disposed.
19. The display device of claim 18 , wherein a plurality of bank holes are disposed in the second area.
20. The display device of claim 19 , wherein the second driving electrode is disposed to extend to the second area and is formed so as to not be disconnected in a bank hole from the plurality of bank holes.
21. The display device of claim 20 , wherein the second driving electrode is connected to the lower connection line at least once through the plurality of bank holes and is disposed to be spaced apart from the bank etch layer.
22. The display device of claim 21 , wherein an edge of the bank etch layer disposed in the display area is more inset from an edge of a lower end portion of the first bank layer portion in the display area than the edge of the bank etch layer disposed in the non-display area with respect to the lower end portion of the second bank layer portion in the non-display area.
23. The display device of claim 19 , wherein the bank layer includes a bank open portion in an emission part of the display area, and the bank hole is formed to be ⅓ to ⅕ of a size of the bank open portion.
24. The display device of claim 19 , wherein an interval between the plurality of bank holes is ⅓ to ⅕ smaller as compared with an interval between the bank layer of the display area.
25. The display device of claim 18 , wherein, in the fourth area, a dam is disposed on the power supply line.
26. The display device of claim 25 , wherein the dam is formed by stacking a first intermediate layer, a second intermediate layer, the bank layer, and a spacer.
27. The display device of claim 26 , wherein the second area is implemented such that the first and second intermediate layers are separated by the lower connection line and the second driving electrode to block moisture permeation.
28. The display device of claim 26 , wherein the bank layer and the spacer are made of a same material.
29. The display device of claim 17 , wherein the bank layer is made of a material having an etch rate different from an etch rate of the bank etch layer.
30. The display device of claim 17 , wherein a lower end portion of the bank layer is vertically spaced apart from an upper portion of the first driving electrode.