Eliminating ‘Garbage In, Garbage Out’ With Checks and Balances

Reading time ( words)

The proverbial saying “garbage in, garbage out” holds true in the electronic product development world. PCB designers stand squarely in the middle of a busy information intersection flowing with inputs and outputs. Missing or bad information at the beginning of a design project will undoubtedly lead to board re-spins, increased costs, and most importantly, a delayed product release. The same can be said about the PCB designer who doesn’t provide a fully checked and comprehensive data package to the downstream manufacturers, i.e., “throwing it over the fence.”

Certainly, there is only so much a person can do with wrong or missing information, but to help ensure the success of a design project, it is incumbent upon the PCB designer to have systems in place to manage the flow of information through documented standards and guidelines, effective communication, and a series of checks and balances.

It is important to understand that most electrical engineers are not PCB designers, and many do not know exactly what information is required. Therefore, it is up to the PCB designer to be proactive and to request all the information and specifications needed for the project beyond the obvious items (schematic, mechanical, and BOM). This can be accomplished with a design specification document as we employ at Optimum or just a document checklist of items, such as the items listed below:

  • Component datasheets and application notes
  • Placement floor plan
  • Stack-up, copper weight, material, via spans, etc.
  • ICT or flying probe requirements
  • Copper constraints that address impedance, timing, topology, current, etc.
  • Board nomenclature details/special notes 

As with most things in life, effective communication is key to ensuring information is not missed. At Optimum, every design project begins with a kick-off meeting (via Zoom these days), preferably with all the stakeholders present, but at a minimum between the electrical engineer and PCB designer to go over the details regarding the project. This is a great time, if not already provided, to document items such as from the example list above into a design specification.

Once a design project begins, the PCB designer will inevitably have questions or concerns about something in the input package—an obvious schematic error, mechanical conflict, etc. Although a phone call is great, we have found sometimes engineers would rather communicate via email. We find it better to keep emails short and concise. Lengthy emails with too many questions (more than three) will generally result in some questions going unanswered.

On extra-large design projects that may span many months, there can be literally hundreds of emails, most with very important information from a variety of stakeholders. In these cases, it is very easy, due to a variety of reasons, for an instruction to be missed or forgotten. We find it best to organize these emails by moving them into a Word or Excel document where they can be tracked through a typical color-coding system (red, yellow, and green) to ensure nothing gets missed.

To read this entire article, which appeared in the March 2021 issue of Design007 Magazine, click here.



Suggested Items

Why We Simulate

04/29/2021 | Bill Hargin, Z-zero
When Bill Hargin was cutting his teeth in high-speed PCB design some 25 years ago, speeds were slow, layer counts were low, dielectric constants and loss tangents were high, design margins were wide, copper roughness didn’t matter, and glass-weave styles didn’t matter. Dielectrics were called “FR-4” and their properties didn’t matter much. A fast PCI bus operated at just 66 MHz. Times have certainly changed.

Bridging the Simulation Tool Divide

04/12/2021 | I-Connect007 Editorial Team
Todd Westerhoff of Siemens EDA recently spoke with the I-Connect007 Editorial Team about the divide between users of high-powered enterprise simulation tools and those who need a more practical tool for everyday use, and how Siemens is working to bridge the gap. Todd also shared his views on why so many engineers do not use simulation, as well as advice for engineers just getting started with simulation tools.

Barry Olney’s High-Speed Simulation Primer

04/09/2021 | I-Connect007 Editorial Team
The I-Connect007 editorial team recently spoke with Barry Olney of iCD about simulation. Barry, a columnist for Design007 Magazine, explains why simulation tools can have such a steep learning curve, and why many design engineers are still not using simulation on complex high-speed designs.

Copyright © 2021 I-Connect007. All rights reserved.