FINE LINE THIN DIELECTRIC CIRCUIT-BOARD CHARACTERIZATION

The rough surface of the copper foil, introduced to enhance its interf acial adhesion to the dielectric medium, will increase the signal prop agation time constant and reduce the characteristic impedance of a sig nal line, The influence increases as the dielectric thickness decrease s, Two high resolution resonant measurement techniques will be present ed for such studies. The additional delay term due to the internal ind uctance at the frequency of interest is proportional to the square roo t of the signal rise time in the transient measurement, The additional delay associated with the signal rise time degradation due to skin ef fect resistance loss is minimized by measuring the delay at 1% of the voltage swing, We wilt also compare the results of different measureme nt techniques in this paper.