Flexible circuit board, COF module and electronic device comprising the same

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.

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.