Wiring substrate and display device including the same

1 . A display device comprising:

a display area and a pad area disposed on a side of the display area; and

conductive layers comprising wires and conductive patterns disposed in the display area and the pad area on a substrate,

wherein at least one of the conductive layers comprises a copper-indium alloy and comprises a metal layer having a grain size equal to or less than about 140 nm.

2 . The display device of claim 1 , wherein the metal layer has a resistivity equal to or less than about 2.3 μΩcm.

3 . The display device of claim 1 , wherein the metal layer has an indium content equal to or less than about 1 at %.

4 . The display device of claim 3 , wherein the metal layer has an indium content equal to or less than about 0.4 at %.

5 . The display device of claim 1 , wherein the metal layer has a thickness in a range of about 2,000 Å to about 20,000 Å.

6 . The display device of claim 5 , wherein

the metal layer has a thickness in a range of about 7,500 Å to about 8,500 Å, and

a sheet resistance value in a range of 0.02 about Ω/□ to about 0.03 Ω/□.

7 . The display device of claim 5 , wherein

the metal layer has a thickness in a range of about 2,500 Å to about 3,500 Å, and

a sheet resistance value in a range of about 0.06 Ω/□ to about 0.08 Ω/□.

8 . The display device of claim 1 , wherein the metal layer has a line edge roughness equal to or less than about 0.195 μm.

9 . The display device of claim 1 , further comprising:

a via layer disposed on the conductive layers in the display area,

wherein the conductive layers comprises:

a first conductive layer comprising a lower metal layer disposed in the display area and a first pad wire disposed in the pad area;

a second conductive layer comprising gate electrodes disposed in the display area on the first conductive layer and a second pad wire disposed in the pad area; and

a third conductive layer comprising a first conductive pattern disposed in the display area on the second conductive layer and a pad electrode lower layer disposed in the pad area, and

the display device further comprising:

a pad electrode upper layer disposed on the pad electrode lower layer in the pad area; and

a pad electrode capping layer disposed on the pad electrode upper layer.

10 . The display device of claim 9 , further comprising:

a first gate insulating layer disposed between the first conductive layer and the second conductive layer;

a first interlayer insulating layer disposed between the second conductive layer and the third conductive layer; and

a first passivation layer disposed on the third conductive layer,

wherein each of the first gate insulating layer, the first interlayer insulating layer, and the first passivation layer contains an inorganic insulating material.

11 . The display device of claim 10 , wherein

the conductive layer further comprises a fourth conductive layer disposed on the third conductive layer and comprising a first voltage line and a second voltage line, and

the display device further comprises:

a second interlayer insulating layer disposed on the first passivation layer; and

a second passivation layer disposed on the fourth conductive layer.

12 . The display device of claim 11 , further comprising:

a first electrode and a second electrode disposed on the via layer in the display area and spaced apart from each other;

a first insulating layer disposed on the first electrode and the second electrode;

light emitting elements disposed on the first electrode and the second electrode spaced apart from each other on the first insulating layer;

a first connection electrode disposed on the first electrode and electrically contacting the light emitting element; and

a second connection electrode disposed on the second electrode and electrically contacting the light emitting element, wherein

the via layer comprises a trench exposing a portion of a top surface of the second passivation layer,

at least a portion of the first electrode and the second electrode is disposed directly on the second passivation layer in the trench, and

the light emitting elements are disposed in the trench.

13 . The display device of claim 12 , wherein

the pad electrode upper layer, the first electrode, and the second electrode contain a same material, and

the pad electrode capping layer, the first connection electrode, the second connection electrode contain a same material.

14 . A wiring substrate comprising:

conductive layers comprising wires and conductive patterns disposed on a substrate; and

at least one insulating layer disposed between the conductive layers,

wherein at least one of the conductive layers contains a copper-indium alloy, and comprises a metal layer having a grain size equal to or less than about 140 nm and a resistivity equal to or less than about 2.3 μΩcm.

15 . The wiring substrate of claim 14 , wherein the metal layer has an indium content equal to or less than about 1 at %.

16 . The wiring substrate of claim 15 , wherein the metal layer has an indium content equal to or less than about 0.4 at %.

17 . The wiring substrate of claim 14 , wherein the metal layer has a thickness in a range of about 2,000 Å to about 20,000 Å.

18 . The wiring substrate of claim 17 , wherein

the metal layer has a thickness in a range of about 7,500 Å to about 8,500 Å, and

a sheet resistance value in a range of about 0.02 Ω/□ to about 0.03 Ω/□.

19 . The wiring substrate of claim 17 , wherein

the metal layer has a thickness in a range of about 2,500 Å to about 3,500 Å, and

a sheet resistance value in a range of about 0.06 Ω/□ to about 0.08 Ω/□.

20 . The wiring substrate of claim 14 , wherein the metal layer has a line edge roughness equal to or less than about 0.195 μm.