Flexible circuit board, COF module and electronic device comprising the same
A flexible circuit board and an electronic device including a flexible circuit board are provided. The flexible circuit board may include a substrate having a bending area and a non-bending area, a wiring pattern layer provided on the bending area and the non-bending area, a plating layer provided on the wiring pattern layer and including an open area in an area corresponding to the bending area, and a protective layer that directly contacts one surface of the wiring pattern layer exposed at the open area and a side surface of the plating layer. The protective layer may have a larger thickness than a thickness of the plating layer.
1. A flexible circuit board comprising:
a substrate having a bending area and a non-bending area;
a first wiring pattern layer provided on the bending area and the non-bending area on a first surface of the substrate;
a first plating layer provided on the first wiring pattern layer, and including a first open area in an area corresponding to the bending area;
a second plating layer provided on the first plating layer;
a first protective layer that directly contacts one surface of the first wiring pattern layer exposed at the first open area, a side surface of the first plating layer, and a side surface of the second plating layer;
a second wiring pattern layer provided on the bending area and the non-bending area on a second surface opposite to the first surface of the substrate;
a third plating layer provided on the second wiring pattern layer;
a fourth plating layer provided on the third plating layer; and
a second protective layer provided on an area corresponding to the bending area on the second surface of the substrate,
wherein the first protective layer is provided higher than an upper surface of the second plating layer, a width of a second open area of the second plating layer is larger than a width of the first open area of the first plating layer, and an upper surface of the first plating layer exposed in the second open area is in direct contact with the first protective layer.
2. The flexible circuit board of claim 1 , wherein the first protective layer is provided on at least a part of the bending area.
3. The flexible circuit board of claim 1 , wherein a width of a contact area between the first protective layer and the first wiring pattern layer is equal to a width of a contact area between the second protective layer and the second wiring pattern layer.
4. The flexible circuit board of claim 1 , wherein at least one protective layer of the first protective layer and the second protective layer has a thickness of 1 to 20 μm.
5. The flexible circuit board of claim 1 , wherein the third plating layer and the fourth plating layer include an open area in an area corresponding to the bending area, and the second protective layer contacts one surface of the second wiring pattern layer.
6. The flexible circuit board of claim 5 , wherein an open area on the first surface of the substrate vertically overlaps with an open area on the second surface of the substrate.
7. The flexible circuit board of claim 1 , wherein the second protective layer is in contact with one surface of the fourth plating layer.
8. A flexible circuit board chip package comprising the flexible circuit board of claim 1 , wherein the plating layer is connected to a chip in an area where the protective layer is not provided.
9. An electronic device comprising the flexible circuit board of claim 1 , further comprising:
a display panel connected to a first end of the flexible circuit board; and
a printed circuit board connected to a second end opposite to the first end of the flexible circuit board.
10. The flexible circuit board of claim 1 , wherein a cross-sectional shape of at least one protective layer of the first protective layer and the second protective layer is T-shaped.
11. The flexible circuit board of claim 1 , wherein the first protective layer has a shape different from a shape of the second protective layer.
12. The flexible circuit board of claim 1 , wherein one protective layer of the first protective layer and the second protective layer have an upper surface and a lower surface, the upper surfaces having widths different from widths of the lower surfaces.
13. The flexible circuit board of claim 12 , wherein a width of the upper surface of the one protective layer of the first protective layer is larger than the width of the lower surface of the one protective layer of the first protective layer.
14. The flexible circuit board of claim 1 , wherein a thickness of the first protective layer is larger than a thickness of the second protective layer.
15. The flexible circuit board of claim 1 , wherein an outer side of a first end of the bending area includes a first overlapping region in which the first plating layer and the first protective layer are in contact with each other, and an outer side of a second end of the bending area includes a second overlapping region in which the first plating layer and the first protective layer are in contact with each other.
16. The flexible circuit board of claim 15 , wherein a width of the first overlapping region corresponds to or is different from a width of the second overlapping region.
17. A flexible circuit board, comprising:
a substrate including a bending area and a non-bending area;
a first wiring pattern layer provided on the bending area and the non-bending area on a first surface of the substrate;
a first plating layer provided on the first wiring pattern layer, and including a first open area in an area corresponding to the bending area;
a second plating layer provided on the first plating layer;
a first protective layer that directly contacts one surface of the first wiring pattern layer exposed at the first open area, a side surface of the first plating layer, and a side surface of the second plating layer;
a second wiring pattern layer provided on the bending area and the non-bending area on a second surface opposite to the first surface of the substrate;
a third plating layer provided on the second wiring pattern layer;
a fourth plating layer provided on the third plating layer; and
a second protective layer provided on an area corresponding to the bending area on the second surface of the substrate,
wherein the first protective layer is provided higher than an upper surface of the second plating layer, the first protective layer includes an upper first protective layer and a lower first protective layer, and the upper first protective layer is in direct contact with the upper surfaces of the lower first protective layer and the second plating layer.
18. The flexible circuit board of claim 17 , wherein the upper first protective layer includes an overlapping region in contact with the second plating layer, and a width of the overlapping region is larger than a sum of thicknesses of the first plating layer and the second plating layer.
19. The flexible circuit board of claim 17 , wherein a width of a second open area of the second plating layer corresponds to a width of the first open area of the first plating layer.
20. A flexible circuit board comprising:
a substrate having a bending area and a non-bending area;
a first wiring pattern layer provided on the bending area and the non-bending area on a first surface of the substrate;
a first plating layer provided on the first wiring pattern layer, and including a first open area in an area corresponding to the bending area;
a second plating layer provided on the first plating layer;
a first protective layer that directly contacts one surface of the first wiring pattern layer exposed at the first open area, a side surface of the first plating layer, and a side surface of the second plating layer;
a second wiring pattern layer provided on the bending area and the non-bending area on a second surface opposite to the first surface of the substrate;
a third plating layer provided on the second wiring pattern layer;
a fourth plating layer provided on the third plating layer; and
a second protective layer provided on an area corresponding to the bending area on the second surface of the substrate,
wherein the first protective layer is provided higher than an upper surface of the second plating layer, the second protective layer includes an upper second protective layer and a lower second protective layer, and the upper second protective layer directly contacts the upper surfaces of the lower second protective layer and the fourth plating layer.