Display device having a plurality of pad layers and method of manufacturing the same
A display device includes a base layer including an upper base layer and a lower base layer on a rear surface of the upper base layer; at least one light emitting element on a surface of the upper base layer; and at least one pad on the rear surface of the upper base layer and including a first pad layer adjacent to the upper base layer and a second pad layer adjacent to the lower base layer. The second pad layer includes indium zinc oxide (IZO).
1 . A display device comprising:
a base layer including:
an upper base layer; and
a lower base layer on a rear surface of the upper base layer;
at least one light emitting element on a surface of the upper base layer; and
at least one pad on the rear surface of the upper base layer and including:
a first pad layer adjacent to the upper base layer; and
a second pad layer adjacent to the lower base layer,
wherein the second pad layer includes indium zinc oxide (IZO),
wherein the lower base layer does not overlap the second pad layer and forms an open area in a plan view.
2 . The display device of claim 1 , further comprising:
a display area in which a pixel including the at least one light emitting element is disposed;
a non-display area adjacent to at least a portion of the display area;
a driving chip that provides an electrical signal to the pixel; and
a chip-on-film on which the driving chip is provided, wherein
the at least one pad is electrically connected to the chip-on-film, and
the chip-on-film and the driving chip overlap the display area in a plan view.
3 . The display device of claim 2 , further comprising:
a lower connection electrode on the surface of the upper base layer and electrically connected to the at least one pad.
4 . The display device of claim 3 , wherein
the at least one pad each includes an extension pad layer,
the extension pad layer and the first pad layer are integral with each other, and
the lower connection electrode is electrically connected to the extension pad layer.
5 . The display device of claim 1 , wherein
the base layer further includes a barrier layer between the upper base layer and the lower base layer,
the barrier layer includes:
a first barrier layer adjacent to the upper base layer; and
a second barrier layer adjacent to the lower base layer, and
the first barrier layer covers a surface of the first pad layer.
6 . The display device of claim 5 , wherein
the second barrier layer covers a portion of a side surface of the first pad layer, exposes another portion of the side surface of the first pad layer, and does not cover a side surface of the second pad layer, and
the at least one pad protrudes with respect to the barrier layer.
7 . The display device of claim 6 , wherein a thickness of a protrusion of the at least one pad protruding with respect to the barrier layer is greater than a thickness of the second pad layer.
8 . The display device of claim 7 , wherein
the thickness of the protrusion is in a range of about 4,000 Å to about 7,000 Å, and
the thickness of the second pad layer is in a range of about 500 Å to about 700 Å.
9 . The display device of claim 5 , wherein the second barrier layer covers an entire side surface of the first pad layer and exposes at least a portion of a side surface of the second pad layer.
10 . The display device of claim 5 , wherein the second barrier layer exposes an entire side surface of the second pad layer.
11 . The display device of claim 1 , wherein the display device is provided as a tiled display device including a plurality of display devices.
12 . An electronic device comprising the display device of claim 1 .
13 . A display device comprising:
a base layer including:
an upper base layer; and
a lower base layer on a rear surface of the upper base layer;
at least one light emitting element on a surface of the upper base layer; and
at least one pad on the rear surface of the upper base layer and including:
a first pad layer adjacent to the upper base layer; and
a second pad layer adjacent to the lower base layer,
wherein
the second pad layer includes indium zinc oxide (IZO),
the base layer further includes a barrier layer between the upper base layer and the lower base layer,
the barrier layer includes:
a first barrier layer adjacent to the upper base layer; and
a second barrier layer adjacent to the lower base layer,
the first barrier layer covers a surface of the first pad layer,
the upper base layer includes polyimide,
the lower base layer includes polyimide,
the first barrier layer has a structure in which a layer including silicon nitride and a layer including silicon oxynitride are alternately disposed, and
the second barrier layer has a structure in which a layer including amorphous silicon and a layer including silicon oxide are alternately disposed.