Characterization of Electrodeposited Copper Foil Surface Roughness for Accurate Conductor Power Loss Modeling

As computer data rates have increased, designers observed that the standard models for estimating the impact of copper foil surface roughness on conductor loss are limited to a few GHz. The more recent snowball model (a “snowball” estimation of the Huray Model) has demonstrated improved conductor loss predictions up to 50 GHz by estimating the necessary parameters using reasonable assumptions about the geometric surface features of electrodeposited copper foil. Since then, the Huray Model has been incorporated into commercial electromagnetic field simulators. However, a standard method of characterizing the electrodeposited copper foil used in high-speed circuits to directly implement the snowball model has not yet been fully established. Therefore, the primary objective of this thesis was to develop a method of more accurately characterizing the geometric parameters of electrodeposited copper foil surfaces for accurate conductor loss modeling as defined by the snowball model. This thesis demonstrates the first methods of directly characterizing electrodeposited copper foil surface roughness to obtain snowball model parameters. Additionally, this research further legitimizes the analytic form of the snowball model as it pertains to scattered power, demonstrates the practical impact of its parameters, and reveals a source of existing irregularities between the estimated model parameters and actual performance measurements