Detection of transmission lines discontinuities on printed circuit boards based on signal frequency analyses

Many transmission lines discontinuities such as cracks, short connections and changes of the conductive line width can create during printed circuit boards manufacturing. There are different methods for detection of these discontinuities on printed circuit boards (electrical and optical test methods) [1]. Unfortunately, these detection methods are not universal and particular methods do not detect all discontinuities especially for multilayer printed circuit boards where the transmission lines are hidden. For detection of hidden discontinuities we have to use special processes (scratch patterns) and equipment (microscope). The goal was to find a simple method for discontinuities detection on printed circuit boards without scratch patterns and microscopy.