and a third insulating layer 415 arranged in sequence and the second area 430 includes a first insulating layer 431 a first conductive layer 432 a second insulating layer 433 arranged in sequence and considered as a circuit area and at least one through hole 458 passing through the first conductive layer 452 the second insulating layer 453 and the second conductive layer 454 the first insulating layer 451 in the third area 450 includes a solder pad area 456 for exposing the first conductive layer 452 and the third insulating layer 455 includes a bonding area 457 for exposing the second conductive layer 454 and contacting a bonding head 459 the surface of the second conductive layer 454 exposed from the bonding area 457 could include a metal layer which is a single layer metal layer such as a gold layer or a double layer metal layer such as a nickel layer and a gold layer these materials are used for example to describe the present invention and not intended to limit the invention it is noteworthy that the through hole 458 is formed beyond the range of the solder pad area 456 and the bonding area 457 and the through hole 458 includes an electric conductive material such as nickel or any other substance having a thermal conductive property in addition the materials used for the first conductive layer 452 and the second conductive layer 454 could include a copper clad and an adhesive layer could be included between layers referring to fig4 and 5 a flexible printed circuit board and a flow chart of a manufacture process of a flexible printed circuit board according to a preferred embodiment of.