Flexible display panel and manufacturing method thereof

1. A flexible display panel comprising:

a flexible substrate including a display area and a peripheral area outside of the display area;

a wire or an organic layer disposed on the flexible substrate;

an insulating layer disposed on the flexible substrate; and

a neutral plane balancing layer disposed in the peripheral area, not disposed in the display area, and having a curvature radius which is greater than a curvature radius of the wire or the organic layer overlapping the neutral plane balancing layer,

wherein the peripheral area of the flexible substrate in which the neutral plane balancing layer is disposed is folded along a first bending line towards a rear side of the display area,

the neutral plane balancing layer overlaps the first bending line, and

a side surface of the neutral plane balancing layer is in contact with a side surface of the insulating layer.

2. The flexible display panel of claim 1 , wherein

a lower passivation film is disposed under the flexible substrate, and

a bottom side of the lower passivation film includes a plurality of grooves.

3. The flexible display panel of claim 1 , wherein

a thickness of the neutral plane balancing layer is from about 10 μm to about 150 μm.

4. The flexible display panel of claim 1 , wherein

the neutral plane balancing layer includes a resin including acryl or silicon.

5. The flexible display panel of claim 4 , wherein

the neutral plane balancing layer further includes nanoparticles or micro-particles.

6. The flexible display panel of claim 1 , wherein

a curvature radius of the flexible substrate folded along the first bending line is from about 0.5 mm to about 10 mm.

7. The flexible display panel of claim 1 , further comprising:

a display element layer including a plurality of thin film transistors, a plurality of light emitting elements, and an encapsulation layer sealing the light emitting elements.

8. The flexible display panel of claim 1 , wherein

the peripheral area includes a first peripheral area in which a wiring portion is disposed and a second peripheral area in which a pad area is disposed, and

the neutral plane balancing layer is formed in the second peripheral area.

9. A flexible display panel comprising:

a flexible substrate including a display area and a peripheral area outside of the display area;

a wire or an organic layer disposed on the flexible substrate;

a neutral plane balancing layer disposed in the peripheral area, not disposed in the display area, and having a curvature radius which is greater than a curvature radius of the wire or the organic layer overlapping the neutral plane balancing layer;

a lower passivation film disposed under the flexible substrate; and

an insulating layer disposed on the flexible substrate,

wherein the peripheral area of the flexible substrate is folded along a first bending line towards a rear side of the display area,

the neutral plane balancing layer overlaps the first bending line, and

a side surface of the neutral plane balancing layer is in contact with a side surface of the insulating layer.

10. The flexible display panel of claim 9 , wherein

a part of the peripheral area folded towards the rear side of the display area is folded outwards along a second bending line disposed outside of the first bending line.

11. A manufacturing method for a flexible display panel, comprising:

forming a plurality of layers on a flexible substrate which includes a display area and a peripheral area outside of the display area, the plurality of layers including an insulating layer;

forming a neutral plane balancing layer on the plurality of layers in the peripheral area, and not in the display area; and

folding the peripheral area of the flexible substrate where the neutral plane balancing layer is disposed towards a rear side of the display panel along a first bending line to have a curvature radius greater than a curvature radius of a layer of the plurality of layers overlapping the neutral plane balancing layer,

wherein the neutral plane balancing layer overlaps the first bending line, and

a side surface of the neutral plane balancing layer is in contact with a side surface of the insulating layer.

12. The manufacturing method of claim 11 , further comprising:

attaching a lower passivation film to a bottom side of the flexible substrate, wherein a bottom side of the lower passivation film includes a plurality of grooves.

13. A manufacturing method for a flexible display panel, comprising:

forming a plurality of layers on a flexible substrate which includes a display area and a peripheral area outside of the display area, the plurality of layers including an insulating layer;

forming a neutral plane balancing layer on the plurality of layers in the peripheral area, and not in the display area;

attaching a lower passivation film to a bottom side of the flexible substrate; and

bending the peripheral area of the flexible substrate towards a rear side of the display area along a first bending line to have a curvature radius greater than a curvature radius of a layer of the plurality of layers overlapping the neutral plane balancing layer,

wherein the neutral plane balancing layer overlaps the first bending line, and

a side surface of the neutral plane balancing layer is in contact with a side surface of the insulating layer.

14. The manufacturing method of claim 13 , further comprising:

before bending of the peripheral area of the flexible substrate towards the rear side of the display area along the first bending line, folding a part of the peripheral area forward along a second bending line disposed outside of the first bending line.