Melinda Piket-May has been a Professor at the University of Colorado Boulder for 27 years. Her areas of research include signal integrity, computational electrodynamics, assistive technology for special needs, engineering education and pre-collegiate outreach. She is very involved in faculty governance and has won numerous teaching and research awards.
With the recent introduction of the Averatek Semi-Additive Process (A-SAP) process, linewidths under 1 mil are possible using the same fabrication processing line as for traditional 4 mil wide lines. This opens up the possibility of using narrower traces in the BGA escape region than in long-path routing regions. However, using this routing architecture means the narrower traces in the BGA escape field are at a higher impedance than the wider, 50 ohm traces in the routing region. So, how long can these traces be before the impedance mismatch is a problem? The authors of this piece propose an analysis methodology to find out.
It’s easy to make a measurement in most instruments, but it’s sometimes hard to know what is real and what is an artifact. Gibbs Ringing is a common artifact in high-speed scope and TDR measurements that can lead you astray unless you understand how to avoid it. We reveal the secrets of avoiding this important artifact.
Few topics are as fundamental in signal integrity and create as much confusion as signal bandwidth. What exactly does bandwidth refer to and what features in the time domain influence bandwidth; rise time or slew rate?
The first goal in any high-speed board stack up design is to engineer interconnects with a target impedance, and the first step in this process is to use a 2D field solver to explore design space with a virtual prototype. Just how well can a field solver predict the impedance of traces on a real board? This article aims to answer this question.