1. first, the FPC line factory will observe the line of the problem with microscope and find the location of the suspected fault.

2. if the microscope can not find any suspicious fault location, then the FPC line factory can divide the circuit into several small sections.

3. at both ends of the line that may break, or the position of the segment, cut the outer layer of the soft plate with the blade carefully. It is best to take the new aesthetic tool or the carving knife, then move the blade to the outer layer to remove the outer membrane and expose the copper foil below. So you can take three meters to measure the circuit. Then the position of the fracture may be eliminated step by step, and finally the exact fracture location of the copper foil line can be found.

4. if it is concerned that this method may break the copper foil line, the FPC line plant can also try to cut the position of copper foil at the side of the copper foil, and then try to tear off the outer layer of the coating to achieve the same purpose.

5. once the exact location of the copper foil line is found, if the fracture is not observed, the FPC line factory will try to bend the soft plate under the microscope so that the opening of the broken copper foil can be highlighted and amplified.