Flexible display apparatus

1. A flexible display apparatus comprising:

a substrate;

a display unit for displaying an image and located on the substrate;

a non-display area located on the substrate and formed outside the display unit, the non-display area comprising:

a stiffener comprising a plurality of reinforcement lines formed on the substrate and patterned to reduce or prevent thermal deformation of the substrate;

at least one pad formed on and electrically insulated from each of the reinforcement lines; and

a stiffener insulating layer between the reinforcement lines and the at least one pad, the stiffener insulating layer being configured to electrically insulate each of the reinforcement lines from the at least one pad; and

a circuit board comprising circuit terminals to be electrically connected to the at least one pad,

wherein the reinforcement lines are arranged apart from one another by a first distance in one direction of the substrate and are arranged in another direction of the substrate to constitute an aggregate having a regular pattern,

wherein the display unit comprises an organic light-emitting display apparatus comprising:

a semiconductor active layer having a source/drain region and a channel region;

a gate insulating layer formed on the semiconductor active layer;

a gate electrode formed on the gate insulating layer;

an interlayer insulating layer formed on the gate electrode and having a contact hole formed in the interlayer insulating layer;

a source/drain electrode that is electrically connected to the source/drain region;

a protective layer comprising a passivation layer and/or planarization layer formed on the interlayer insulating layer; and

a display device,

wherein the at least one pad is electrically connected to the gate electrode or the source/drain electrode,

wherein the at least one pad is patterned of a same material as a material for forming the source/drain electrode, and

wherein the stiffener is patterned of a same material as a material for forming the gate electrode.

2. The flexible display apparatus of claim 1 , wherein patterns of the reinforcement lines are separated from one another, and

a space is formed between adjacent reinforcement lines.

3. The flexible display apparatus of claim 2 , wherein the reinforcement lines comprise one selected from the group consisting of a plurality of serpentine type patterns, a plurality of zigzag type patterns, a plurality of network type patterns, a plurality of honeycomb type patterns, a plurality of straight type patterns, a plurality of curve type patterns, a plurality of circular shapes, and a plurality of polygonal shapes.

4. The flexible display apparatus of claim 1 , wherein the at least one pad overlays at least a portion of the reinforcement lines.

5. The flexible display apparatus of claim 4 , wherein the reinforcement lines are arranged between the at least one pad and the substrate.

6. The flexible display apparatus of claim 4 , wherein an insulating material is further deposited between the stiffener and the at least one pad.

7. The flexible display apparatus of claim 1 , wherein

the at least one pad is arranged in a first direction of the substrate,

each reinforcement line is arranged in the first direction, and

a perimeter of an aggregate of the reinforcement lines is arranged to contain a perimeter of the at least one pad in a second direction of the substrate that crosses the first direction.

8. The flexible display apparatus of claim 1 , wherein a thermal expansion coefficient of each reinforcement line is smaller than a thermal expansion coefficient of the substrate.

9. The flexible display apparatus of claim 8 , wherein

the substrate is formed of a polymer, and

each reinforcement line is formed of metal.

10. The flexible display apparatus of claim 1 , wherein the substrate comprises a flexible substrate.

11. The flexible display apparatus of claim 10 , wherein the substrate is formed of one selected from the group consisting of polyimide (PI), polycarbonate (PC), polyethersulphone (PES), polyethylene terephthalate (PET), polyethylenenaphthalate (PEN), polyarylate (PAR), or fiber glass reinforced plastic (FRP).

12. The flexible display apparatus of claim 1 , wherein

the at least one pad is arranged on the non-display area of the substrate, and

the stiffener is patterned between the substrate and the at least one pad.

13. The flexible display apparatus of claim 12 , wherein an insulating material is further deposited between the at least one pad and the stiffener.

14. The flexible display apparatus of claim 1 , further comprising an integrated circuit (IC) mounted on the circuit board, wherein the circuit board comprises a flexible film.