Patent ID: 8453324

Claim:
A method for manufacturing a flexible printed circuit board substrate, the method comprising: providing a flexible printed circuit board material comprising an insulation layer and an electrically conductive layer formed on the insulation layer, the electrically conductive layer having a first surface and a second surface at an opposite side thereof to the first surface, the insulation layer having a third surface and a fourth surface at an opposite side thereof to the third surface, the third surface of insulation layer coming into contact with the second surface of the electrically conductive layer; forming a first metal hole in the electrically conductive layer; enlarging the first metal hole to form a larger metal hole, and eliminating a portion of the insulation layer corresponding to the larger metal hole to form a first insulation hole, thereby the larger metal hole and the first insulation hole defining a first through hole, the first through hole extending from the first surface of the electrically conductive layer to the fourth surface of the insulation layer; enlarging the first insulation hole to form a larger insulation hole, thereby exposing an exposed edge of the electrically conductive layer surrounding the larger metal hole; and bending the exposed edge of the electrically conductive layer to form a petal-shaped hook having two petals which pass through the larger insulation hole and protrude from the fourth surface of the insulation layer.