Avoid These 5 PCB Design Mistakes That Cause Scrap

{
"title": "Avoid These 5 PCB Design Mistakes That Cause Scrap",
"meta_description": "Prevent trace spacing, impedance, copper balancing, via, and layer alignment defects that drive PCB scrap. Improve manufacturability before production.",
"content_markdown": "A single batch of scrapped printed circuit boards can wipe out thousands of dollars in materials, production time, and delayed delivery. Most of that waste is preventable. The root cause almost always traces back to recurring PCB design mistakes—not fabrication limitations. Common errors include insufficient trace spacing, uncontrolled impedance, uneven copper distribution, poor via geometry, and weak layer registration. Missing test points or fiducials add further manufacturability risk that fabricators often discover too late.\n\nApplying design for manufacturability (DFM) principles early in the PCB design process is the most effective way to cut scrap rates. A formal DFM review catches these issues before files reach the fab. This guide provides actionable fixes for each mistake. Improve your PCB design quality and you will improve production yield.\n\n## 1. Trace Spacing and Acid Traps\n\nTraces placed too close together remain a leading reason PCB batches fail. When copper features sit too near each other, the etching process creates acid traps. These traps produce defects that frequently ruin entire boards. Acute angles below 90 degrees allow etchant to pool in sharp corners, corroding copper locally and creating open circuits or shorts. Minimal gaps between pads, traces, and vias let acid seep between conductors, sometimes fusing traces during etching. Isolated copper islands trap etchant that later leaks out and damages adjacent circuitry. Even design software can inadvertently generate acute angles or insufficient clearances, producing the same failures.\n\nA couple of small spacing errors can scrap an entire production order. Thin traces also suffer from overheating and voltage drops, compounding reliability problems. To prevent these defects, follow the fabricator’s DFM rules from the beginning. Every manufacturer publishes minimum spacing requirements; apply them consistently throughout the layout.\n\nThe IPC-2221 standard provides baseline spacing guidelines based on voltage:\n