Patent ID: 7429177

Claim:
A flexible printed circuit (FPC) board, comprising: a wiring layer comprising a plurality of conductive lines, each of the conductive lines comprising a finger, a line portion, and a junction portion between the finger and the line portion, a width of the finger being greater than a width of the line portion, a width of the junction portion gradually changing from the width of the line portion to the width of the finger to prevent overstress or break at the junction when the flexible printed circuit board is bent, two edges of the junction portion being curved lines; the junction portion comprising a first end and a second end, the first end connecting with the line portion, and the second end connecting with the finger; a width of the first end being equal to the width of the line portion, and a width of the second end being equal to the width of the finger; an insulating layer, the insulating layer covering most of the wiring layer; the insulating layer being made from polyimide (PI); a reinforcing layer, the reinforcing layer covering part of the insulating layer to reinforce the mechanical strength of the FPC board an edge portion of the reinforcing layer at a middle portion of the FPC board being wedge-shaped; the reinforcing layer being made from aluminum (Al); the line portions of the conductive lines being made from copper foil, the fingers of the conductive lines being made from gilded copper; the wiring layer further comprising a base, a thickness of the base being in the range from 10 gm to 100 gm.