Detection of printed circuit board failures based on signal frequency analyses

The inspections of printed circuit boards are necessary carry out because of failures and defects detection. Cracks and change of conductive path width are included to the most frequently defects on printed circuits board where are difficulty detected. These defects can cause change of transmission signal integrity thereby it is necessary their detection. New method for detection of these defects was designed. This method is based on measurement of scattering parameters or spectrum of transmission signal. By evaluation of measurement values the failures and defects can be detected. The results obtained by scattering parameters measuring on conductive path with cracks are presented.