Issue link: https://iconnect007.uberflip.com/i/1538269
AUGUST 2025 I DESIGN007 MAGAZINE 39 the screen. Alex opened with good news: She had created every component footprint over the week- end as per the current BOM and populated the lay- out as logically as possible. The parts were placed. She looked around, and saw the nods from her audience—momentarily impressed. Without skipping a beat, an electrical engineer said, "Alex, I added four more ICs and a trans- former to the schematic yesterday. You should see the updated BOM in your inbox." Then a mechan- ical engineer, wanting to be helpful, said, "And I finally locked in the official PCB outline over the weekend, too. Let me pull up the CAD." He launched his 3D model onto the big screen. Alex's jaw dropped. The newly revealed outline was anything but ordinary. It was tight, irregular, and con- toured in a way that made her logical, symmetrical component placement seem like a distant dream. How would she fit those new parts into this geometry? All those carefully crafted footprints suddenly looked like oversized furniture for a stu- dio apartment. Speaking of which, back at the apartment, Lisa was in tears. Movers had unloaded her furniture, which now sat neatly arranged on the sidewalk outside the apartment door. The prob- lem was that the door was too narrow for most of it to get through. What little did fit was wedged diag- onally into the space, lying awkwardly between opposing walls. The entertainment center blocked a closet. When it was empty, the apartment had felt spacious. But now, it was painfully obvious: Floor planning for these living quarters would be impos- sible. There was no way to fit everything inside and still leave space to walk. While Lisa and the movers wrestled with physi- cal space and oversized furniture, Alex faced the same spatial crisis—only in 3D PCB layout form. Both were the result of the same problem: Act- ing on floor planning before obtaining well-defined constraints. In residential and electrical realms, beautiful plans based upon guesswork mean noth- ing if they won't fit through the door. PCB design is complex. Some of it is literally rocket science. But the most frequent bottlenecks aren't found in high-end equations or exotic ICs. They come from skipping the basics. A successful floor plan isn't magic. It's math, logic, and discipline. Measure twice, place once, and make sure it fits through the door. Before starting the layout, make sure you've locked down these three essential constraints: • A well-defined PCB outline, including keepout area and height limitations • A finalized bill of materials • A complete netlist or connectivity plan Anything less, and you're not designing; you're gambling. Finish what's ready. Start what's defined. Begin with the end in sight. DESIGN007 Kelly Dack, CIT, CID+, provides DFx centered PCB design and manufacturing liaison exper- tise for a dynamic EMS pro- vider in the Pacific North- west while also serving as an IPC design certification instructor (CID) for EPTAC. To read past columns, click here. TA RG E T C O N D I T I O N