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

Estimated reading time: 2 minutes

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.