Organic electroluminescent display device

1. An organic electroluminescent display device, comprising:

a substrate including a display region, and first to fourth pad regions in a periphery of the display region, the display region including a pixel region, the first and second pad regions facing the third and fourth pad regions, respectively, the first pad region in one side of the display region, the second pad region in another side of the display region perpendicular to the one side;

a gate line, a data line crossing the gate line, and a power line on the substrate in the display region, the power line crossing one of the gate line and the data line;

a switching thin film transistor and a driving thin film transistor in the pixel region, the switching thin film transistor connected to the gate line and the data line, and the driving thin film transistor connected to the switching thin film transistor and the power line;

a gate pad in one of the first and second pad regions, a data pad in the other one of the first and second pad regions and a power pad in one of the third and fourth pad regions, the gate pad, the data pad and the power pad electrically connected to the gate line, the data line and the power line, respectively;

a first electrode in the pixel region, the first electrode connected to the driving thin film transistor;

an organic electroluminescent layer on the first electrode;

a second electrode over an entire display region of the substrate including the organic electroluminescent layer;

a dummy pad in at least one of the first and second pad regions, the dummy pad electrically connected to at least one of the power line and the second electrode; and

a ground pad in the other one of the third and fourth pad regions, the ground pad electrically connected to the second electrode.

2. The device according to claim 1 , wherein the dummy pad includes a first dummy pad electrically connected to the power line, and a second dummy pad electrically connected to the second electrode.

3. The device according to claim 2 , wherein the gate pad and the first dummy pad are disposed in the first pad region, and the data pad and the second dummy pad are disposed in the second pad region.

4. The device according to claim 2 , wherein the data pad and the first dummy pad are disposed in the first pad region, and the gate pad and the second dummy pad are disposed in the second pad region.

5. The device according to claim 2 , wherein the power pad is disposed in the third pad region, and the ground pad is disposed in the fourth pad region.

6. The device according to claim 1 , wherein the dummy pad is electrically connected to an external circuit by tape automated bonding.

7. The device according to claim 1 , wherein the first electrode acts as an anode.

8. The device according to claim 7 , wherein the first electrode includes indium tin oxide.

9. The device according to claim 1 , wherein the second electrode acts as a cathode.

10. The device according to claim 9 , wherein the second electrode includes one of aluminum (Al), calcium (Ca), magnesium (Mg) and lithium fluorine/aluminum (LiF/Al).