Flexible printed circuit board

A flexible printed circuit board comprising;

• a base film formed of a flexible insulation material and having an end portion and a main portion, the main portion including an interim portion extending from the end portion and a circuit portion extending from the interim portion, the base film including a first connection hole formed adjacent to the end portion and a second connection hole formed at the main portion;
• a first conductive layer formed on an outer surface of the base film including an area covering the first and second connection holes of the base film;
• a second conductive layer formed on an inner surface of the base film including an area covering the first connection hole of the base film, said second conductive layer formation area excluding the main portion of the base film, the second conductive layer being electrically connected to the first conductive layer through the first connection hole;
• a third conductive layer formed on an inner surface of the base film including an area covering the second connection hole of the base film, said third conductive layer formation area excluding the end portion and the interim portion of the base film, the third conductive layer being electrically connected to the first conductive layer through the second connection hole, the third conductive layer being separated from the second conductive layer;
• a first cover layer formed of a flexible insulation material and covering the first conductive layer;
• and
• a second cover layer formed of a flexible insulation material and covering the third conductive layer, said second cover layer formation area excluding the end portion and the interim portion of the base film such that the flexible printed circuit board is subject to repetitive bending primarily at the interim portion thereof without developing cracks in the bending portion.