Roger S. Krabbenhoft

Losses caused by roughness of metallization in printed-circuit boards

In this paper the effect of metal roughness on the total loss, the extracted tan /spl delta/, and signal integrity of typical interconnections found in printed-circuit boards is extracted from measurements on three different materials. The differing characteristics of the roughened metal cross sections are highlighted, and a simplified, practical, two-dimensional, causal, broadband modeling methodology is shown.

iNEMI BFR-free PCB materials evaluation project report

Brominated flame retardants, namely polybrominated diphenyl ethers (PBDEs), were one of the main materials used to reduce the flammability of consumer goods and electronics. Growing evidence shows that PBDE compounds are making their way into the environment. These chemicals may cause health effects, prompting many nations to ban or suspend their use in new consumer goods.

A neural network based method for predicting PCB glass weave induced skew

This paper proposes the use of a neural network based tool to predict the skew factor of PCB laminate differential channel designs. A multitude of differential stripline design scenarios are 3D modelled, each with a different expected within differential pair skew factor. The modelled data is used to train a neural network. The neural network is tested using an unseen set of design data in order to evaluate the goodness of its predictions. Preliminary results show this machine learned technique to be a viable way to predict PCB glass weave skew without the need to resort to intensive 3D modelling. This method has potential to shorten design cycles and simplify analysis while still achieving good simulation accuracy.

Realization of ultra-low power I/O

This paper summarizes the exploratory work conducted at IBM which seeks to reduce electrical I/O power consumption to facilitate both power distribution and device cooling for future exascale computing systems. The development of novel low-loss dielectric materials was coupled with design for performance to achieve low channel loss by minimizing reflections and energy dissipation due to non-ideal current return paths. A printed circuit board was fabricated and tested, with results confirming a 20% reduction of channel loss at 10GHz when compared to currently leading commercial materials. This 3dB improvement in loss for a 15dB channel, can offer a 50% I/O power reduction when used with power scalable driving/receiving circuits.