Design for Manufacturing (DFM) review catches problems before they become scrap or delays. Here are the eight issues our engineers find most often, and how to avoid them.

1. Annular ring too small

Drill registration tolerance means a small annular ring can break out. Keep at least 0.15 mm of copper around the finished hole on dense boards.

2. Acid traps in acute angles

Acute trace angles hold etchant and over-etch the trace neck. Use 45 degree or curved routing instead of sharp angles.

3. Copper slivers

Very thin copper features between spacing rules can flake off during etching. Keep copper features and spacing above your manufacturer minimum.

4. Insufficient trace spacing to board edge

Routing too close to the edge risks exposure of copper during depaneling. Maintain at least 0.3 mm copper-to-edge clearance, more for V-cut boards.

5. Missing thermal relief on plane connections

Direct connections of through-hole pins to large planes make soldering difficult. Use thermal relief spokes unless current carrying demands solid connections.

6. Unbalanced copper distribution

Large solid areas on one layer with sparse copper opposite create warpage risk. Balance copper across layers or add hatched pours.

7. Silkscreen over pads

Legend printed over SMD pads can contaminate solder joints. Move reference designators clear of pads or remove them.

8. Underspecified impedance requirements

Saying controlled impedance without target values forces assumptions. Provide the single-ended and differential pairs with their target impedance and reference layers.

Most of these issues are caught automatically in a professional DFM report. Upload your design for a free review before you order, and keep these rules in your checklist from the start.