Effects of Adhesion Promotion Treatment On Electrical Signal Attenuation

As PCB signal speeds increase, the signal's current path switches from the path of least impedance to the path of least inductance. This path of least inductance is what is commonly known as the "skin effect" whereby an AC signal primarily flows nearer to the outside surfaces of a copper conductor rather than through the entire cross section of the conductor. As frequencies increase, the skin effect becomes more pronounced. Therefore it is very important to understand not only the mechanical reliability aspects of a given PCB design but also the electrical performance criteria it must function under. It is well known that the roughness of the surface of copper conductors can negatively influence electrical signal propagation at high frequencies. The experiment and results described herein quantify the electrical effects an individual OA may have on signal attenuation as well as an examination of the measurement method itself. PCBs were fabricated using a standardized test vehicle using two different oxide alternatives. The electrical characteristics were then measured using the short pulse propagation (SPP) test method. The conclusions are based on these characteristics.