SDG #090 PCB Design Tips and Design Rules

This episode steps away from tool teardowns and examines the part of hobby electronics where mistakes become expensive: laying out a board that a fabricator can build correctly the first time. The focus is on design rules, the constraints set up in the CAD package before routing so that the software catches errors rather than the assembly stage.

The practical value is in understanding where those figures come from. Trace width is driven by current handling and copper weight, clearance by voltage and manufacturing tolerance, and annular ring and drill sizes by what the board house can reliably produce at low cost. Exceeding a manufacturer’s standard capability means either paying for an advanced specification or receiving boards with broken tracks and tented vias that were never meant to be tented. Matching the design rule set to the published capability sheet of the fabricator actually intended is the single highest value habit a beginner can adopt.

Also covered is the wider layout discipline that a design rule check will never flag: sensible component spacing for hand soldering and rework, keeping test points accessible, silkscreen that survives the printing process at small sizes, and considering ground return paths rather than treating a ground pour as automatically good practice.

For anyone whose prototype run has come back unusable, the lesson is that most respins trace back to constraints that were never entered in the first place. Time spent on setup before routing means the board largely checks itself.