-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueOpportunities and Challenges
In this issue, our expert contributors discuss the many opportunities and challenges in the PCB design community, and what can be done to grow the numbers of PCB designers—and design instructors.
Embedded Design Techniques
Our expert contributors provide the knowledge this month that designers need to be aware of to make intelligent, educated decisions about embedded design. Many design and manufacturing hurdles can trip up designers who are new to this technology.
Manufacturing Know-how
For this issue, we asked our expert contributors to share their thoughts on the absolute “must-know” aspects of fab, assembly and test that all designers should understand. In the end, we’re all in this together.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
A Fractal Conversation with Jim Howard and Greg Lucas
January 15, 2019 | Barry Matties and Andy Shaughnessy, I-Connect007Estimated reading time: 3 minutes
Veteran PCB technologists Jim Howard and Greg Lucas have made an interesting discovery: Certain shapes of copper planes make a PCB run more efficiently than other shapes, a process they dubbed fractal design. It doesn’t appear to cost a penny more, and testing suggests that fractal design techniques could eliminate edge noise.
Barry Matties and Andy Shaughnessy asked Jim and Greg to discuss the fractal design process, as well as some of the advantages of using this technique on your next PCB design.
Barry Matties: Gentlemen, tell us how you all got started with fractals and fractal design.
Jim Howard: Greg and I were in the midst of developing a technology known as buried capacitance, and we had a number of tests that we needed to run on PCBs to determine exactly what the effects of having this very thin distributed capacitance within the board would accomplish. We discovered some effects that really didn't gel with what we were doing at that time, but they were of interest.
A few years later, we went back and thought, "These things could be useful," because we discovered that certain shapes on the copper planes of the PCBs—which, at that time, were only dictated by anti-pads and various cuts and things in the copper—either increased or decreased its ability to operate efficiently as a power/ground plane. We didn't know precisely what that effect was.
Then, I spent a few years working for a Chinese company developing some technology for them, and they wanted to see if this was something that I could work on in the future. I found we could create an effect with a specific shape of putting anti-pads, cuts, and other things where we wanted to, but the problem was that no designer was ever going to let you do that. That's an impossible scenario.
So, I discarded that for a moment, and after I left that company as their technical director, I started to think about this particular problem again. I thought, "What related fields can I get information from?" because as an engineer, I can never be too proud to beg. I started investigating unusual bits of science, came across fractals, and immediately recognized the fractals exemplified the patterns we had been creating in their simplest form. The thing I was looking at, at the time, was a Cantor set, which is one of the very early fractal forms.
I researched that, talked to Greg about it, and he thought about it for a while. Then, we realized, "Hey, there's a reason to pursue this." We initially pursued it from the point of view of something very simple that we could initially find a reason for: If we could etch this around the outside of a PCB, perhaps we could reduce the noise given off by the edges of the board. Edge noise was a significant issue with buried capacitance. We started working with it and developing some IP to give us a history in the field, and also to serve as a vehicle for further study.
Next, we created some samples. We went through testing in Silicon Valley at Dr. Earl McCune's laboratory. We did a lot of analysis with Dr. McCune. From that, we derived and sent the samples that gave us the very most interesting results to an FCC testing laboratory with a set of engineers at that end to help us interpret the responses. The responses were as we expected in terms of reducing the noise from the PCB for virtually no cost or no cost that we could think of.
To read this entire interview, which appeared in the December 2018 issue of Design007 Magazine, click here.
Suggested Items
Trouble in Your Tank: Supporting IC Substrates and Advanced Packaging, Part 5
03/19/2024 | Michael Carano -- Column: Trouble in Your TankDirect metallization systems based on conductive graphite or carbon dispersion are quickly gaining acceptance worldwide. Indeed, the environmental and productivity gains one can achieve with these processes are outstanding. In today’s highly competitive and litigious environment, direct metallization reduces costs associated with compliance, waste treatment, and legal issues related to chemical exposure. What makes these processes leaders in the direct metallization space?
AT&S Shines with Purest Copper on World Recycling Day
03/18/2024 | AT&SThe Styrian microelectronics specialist AT&S is taking World Recycling Day as an opportunity to review the progress that has been made in recent months at its sites around the world in terms of the efficient use of resources:
Matrix to Exhibit at IPC APEX EXPO 2024 in Anaheim, CA
03/05/2024 | MatrixMatrix will be exhibiting at IPC APEX EXPO 2024, to be held on April 9-12, 2024, at the Anaheim Convention Center, Anaheim, CA.
The Chemical Connection: Getting to Know Your Vendor
02/16/2024 | Don Ball -- Column: The Chemical ConnectionAfter working for a capital equipment supplier for almost 50 years, I’ve found that the most important part of getting to know your vendor is good communication among all parties. While contact between fabricators of a constantly changing product line and the designers of those products may occur daily or weekly, conversations between you and your equipment supplier may be years apart. That lengthy gap often means that previous contacts may have been promoted, retired, or moved on to other opportunities. You may have also migrated to a new supplier with whom you have little or no history. In either case, you will be interacting with someone you are unfamiliar with (as they are with you). Therefore, it is essential for both sides to communicate clearly so expectations will align.
EIPC Winter Conference 2024, Day 2: A Closer Look at Global Trends
02/14/2024 | Pete Starkey, I-Connect007The opening session of the second day’s conference proceedings focused on global PCB trends and was introduced and moderated by Dr. Michele Stampanoni, vice president of strategic sales and business development at Cicor Group in Switzerland. He opened the session with Dr. Hayao Nakahara’s knowledgeable and enlightening video presentation on the IC substrates industry.