Display panel and display device including the same
A display panel includes a base layer having a display area and a non-display area including a pad area; a plurality of transistors on the base layer; a first protective layer covering the plurality of transistors; a conductive layer on the first protective layer; a second protective layer over the conductive layer; a first electrode and a second electrode on the second protective layer, the first and second electrodes being spaced from each other; a plurality of light emitting elements between the first electrode and the second electrode; a first contact electrode on the first electrode, the first contact electrode being in contact with one end portion of the light emitting element, and a second contact electrode on the second electrode, the second contact electrode being in contact with the other end portion of the at least one light emitting element; and a first pad in the pad area.
1. A display device, comprising:
a base layer having a display area and a non-display area, the non-display area comprising a pad area;
a first insulating layer, a second insulating layer, a third insulating layer, a fourth insulating layer, and a fifth insulating layer sequentially stacked on the base layer; and
a first pad on the first insulating layer in the pad area,
wherein the first pad comprises:
a first pad pattern on the first insulating layer;
a second pad pattern on the first pad pattern with the second insulating layer interposed therebetween;
a third pad pattern on the second pad pattern with the third insulating layer interposed therebetween;
a fourth pad pattern on the third pad pattern and the fourth insulating layer; and
a fifth pad pattern on the fourth pad pattern,
wherein the first to fifth pad patterns are electrically connected to each other.
2. The display device of claim 1 , further comprising:
a first electrode and a second electrode disposed on the fourth insulating layer in the display area, the first and second electrodes being spaced from each other;
a plurality of light emitting elements located between the first electrode and the second electrode;
a first contact electrode on the first electrode, the first contact electrode being electrically connected to a first end portion of at least one light emitting element from among the plurality of light emitting elements; and
a second contact electrode on the second electrode, the second contact electrode being electrically connected to a second end portion of the at least one light emitting element.
3. The display device of claim 2 , wherein:
the fifth pad pattern is located at an uppermost portion of the first pad; and
the fifth pad pattern comprises a same material as the first contact electrode or the second contact electrode.
4. The display device of claim 3 , wherein the fifth pad pattern comprises ITO, IZO, or ITZO.
5. The display device of claim 3 , wherein the fifth pad pattern comprises a groove at an upper portion thereof, and a ratio of width to depth of the groove is 20 or more.
6. The display device of claim 5 , wherein the width of the groove is 20 μm or more, and the depth of the groove is 1 μm or less.
7. The display device of claim 2 , wherein the fourth pad pattern comprises a same material as the first electrode and the second electrode.
8. The display device of claim 2 , further comprising:
a buffer layer between the base layer and the first insulating layer;
a plurality of transistors on the buffer layer;
an interlayer insulating layer between the second insulating layer and the third insulating layer in the display area; and
a conductive layer on the third insulating layer in the display area,
wherein each of the transistors comprises:
a gate electrode on the first insulating layer;
a semiconductor pattern on the buffer layer; and
a source electrode and a drain electrode on the interlayer insulating layer.
9. The display device of claim 8 , wherein:
the first pad pattern comprises a same material as the gate electrode;
the second pad pattern comprises a same material as the source electrode and the drain electrode; and
the third pad pattern comprises a same material as the conductive layer.
10. The display device of claim 2 , wherein:
the fifth insulating layer is located on and covers the first and second contact electrodes in the display area; and
the fifth insulating layer exposes a portion of the fifth pad pattern in the pad area.
11. The display device of claim 2 , further comprising:
a color conversion layer and a color filter on the plurality of light emitting elements.
12. The display device of claim 1 , wherein the second pad pattern and the fifth pad pattern have a same width.
13. The display device of claim 1 , wherein the first pad pattern, the third pad pattern, and the fourth pad pattern have a same width.
14. The display device of claim 1 , wherein:
the second pad pattern is electrically connected to the first pad pattern through a first contact hole in the second insulating layer; and
the third pad pattern is electrically connected to the second pad pattern through a second contact hole in the third insulating layer.
15. The display device of claim 1 , wherein:
the fifth pad pattern is surrounded by the fifth insulating layer; and
a step difference between the fifth pad pattern and the fifth insulating layer is 0.6 μm to 2.0 μm.
16. The display device of claim 15 , wherein:
the fifth insulating layer comprises an area overlapping with an edge of the fifth pad pattern; and
the area has a width of 2 μm to 3 μm.
17. The display device of claim 15 , wherein the fifth insulating layer has a thickness of 6000 Å or less.
18. The display device of claim 1 , further comprising a second pad spaced from the first pad in the pad area,
wherein the first pad is a gate pad and the second pad is a data pad.